Group for Earth Observation

The Independent Amateur Quarterly Publication for

Number 11

Earth Observation and Weather Satellite Enthusiasts

September 2006

Inside this issue . . .
Tropical Cyclones arecovered in depth in an
informative article from
Ferdinand Valk, who
discusses the why, when
and where of Tropical
Storm formation
We also take a close look atcurrent trends in the North
Atlantic and present
evidence that suggests
strongly that recent
heightened hurricane
activity does not owe its
origin to Climate Change.
Arne van Belle reveals moreof his secrets by explaining
how to make the mostefficient use of twin PCs for
EUMETCast reception
Gérard Kruger describes aninteresting technique toenhance your HRPT images
by rendering them in 3D
David Taylor tackles thechallenging issue of data
throughput for
EUMETCast users keen to
add the new EARS-AVHRR
services
And have you heard of‘Ship Waves’: Les Hamilton
describes this unusual
cloud phenomenon you cansee in your weather satellite
imagesPlus many more features ...

Keep up with the latest WXsat News every Month
Radio and Communications Monitoring Monthly provides a regular4-page Weather Satellite column, “Satellites' View”, by Lawrence
Harris. In addition, there is an annual ‘special’ issue covering
WXsats containing additional features and reviews written by
Lawrence.
‘We are pleased to serve all the specialist areas of the hobby’,commented Editor Kevin Nice. ‘I am pleased to say that all of ourregular columns provide more information than any current orformer alternative.’
Radio and Communications Monitoring Monthly (ISSN 1749-7809)
aims to become the magazine of choice for all serious radio
enthusiasts and is available from most good newsagents as well as
direct from the publishers
Subscriptions are available world-wide. For more information
contact Nice One Publishing Ltd, Tel: +44 (0)1202 862690 or visit
the website

CONTACT INFORMATIONF

ollowing several increasingly turbulent years in the North
Atlantic Ocean, the 2005 Hurricane Season proved the mostactive ever recorded, breaking almost every record in the book.
Almost inevitably, pundits around the world seek to pin the cause on
what they variously term ‘Global Warming’ or ‘Climate Change’. But
a recent report in NOAA Magazine explains that there is now
general agreement amongst a number of their hurricane researchersand forecasters that the recent increase in activity is primarily the
result of natural fluctuations in the tropical climate system. You canread about their findings in our page 26 article, which also summarises the final weeks of Hurricane Season and lists the manyrecords achieved.
ontinuing with this stormy theme, Ferdinand Valk has prepared
an in-depth article on the subject of tropical cyclones. If you haveany queries about how and why tropical storms and hurricanes form
you are sure to find your answer here.
ast January, NOAA acceded to requests from many UK-based
GEO members by switching the NOAA-18 APT frequency to137.10 MHz to allow them pager-free reception. Alas, with thisfrequency now required by EUMETSAT for their MetOp satellites,
NOAA-18 resumed transmissions on 137.91 MHz on June 20, a movethat is sure to disappoint many GEO Quarterly readers. We are
grateful to NOAA for having afforded the amateur community thiswindow of opportunity to enjoy NOAA-18 APT at its best throughout
the past six months.

C
L

Contents
GEO Report
Experiments with Receivers and Antennas
Tropical Cyclones
Ship Waves
EUMETCast Reception with a semi 2-PC setup
MSG Images from Dundee Satellite Station
Full Steam Ahead for the A-Train
POVIM Presentation Manager - the Software
Current Developments in EARS-AVHRR
News in Brief

Francis Bell
2John Tellick
4
Ferdinand Valk
5
Les Hamilton
10
Arne van Belle14
Les Hamilton/David Taylor 17
Peter Wakelin
18
Fred van den Bosch
20
David Lee
21
22

GEO Shop
NOAA Satellite Predictions for the UK and western Europe
Helplines and Internet Discussion Groups
Copy Deadline for December issue
GEO Membership Renewal Form

i
ii
iii
iii
iv

POVIM 2 - Automating all processes
Store your APT Recording Level
Hurricane Season 2005 Update
Monitoring Lightning Strikes in Real Time
EUMETCast Data Throughput
HRPT Images in 3D
Warning - Anthriscus sylvestris
Colour Image Details
A Novice’s Experiences setting up MSG
News from Sweden
APT on the Move
Symposium 2006
In Tray - Readers’ Letters
Using the ARSoft RAMdisk on Windows XP
Early Icemelt in the Canadian Arctic
Software Showcase
Earth Imaging NewsSt Georges Channel Sunglint Mystery

23
25
26
29
30
31
34
34
35
36
36
38
39
39
40
41
43
44

Fred van den BoschFred van den BoschLes Hamilton
John Heath
David Taylor
Gérard Kruger
John Tellick
David Tyler
Anders Höök
Norbert Puetz
Peter Green
Arne van Belle
Keith Fraser
Peter Wakelin
Robert Moore

Public Relations
Francis Bell,
Coturnix House,
Rake Lane,
Milford,Godalming,
Surrey GU8 5AB
England.
Tel:(01483) 416 897
e-mail: francis@geo-web.org.uk
General Information
John Tellick
e-mail: info@geo-web.org.uk
EditorLes Hamilton,
8 Deeside Place
Aberdeen AB15 7PW
Scotland, UK.
e-mail: editor@geo-web.org.uk
Membership and Subscriptions
Nigel Evans,
L’Eventail, 7 Gloster Ropewalk, Aycliffe,
Dover CT17 9ES
England, UK.
e-mail: members@geo-web.org.uk
Meteorological Consultant
Peter Wakelin
e-mail: meteo@geo-web.org.uk
Technical Consultant (hardware)David Simmonse-mail: tech@geo-web.org.uk
Webmaster and Website Matters
Ray Godden
e-mail: webmaster@geo-web.org.uk
Education Coordinator
David Paintere-mail: education@geo-web.org.uk
GEO Shop Manager
Clive Finnis
e-mail: shop@geo-web.org.uk
International LiaisonPeter Green‘Hollowtree’
Eggesford
Devon EX18 7QX
Tel:(01769) 580 700
e-mail: international@geo-web.org.uk
PublisherGroup for Earth Observation Ltd.
The Group for Earth Observation Limited is acompany in England and Wales limited byguarantee and not having share capital.
Company number 4975597.
The registered office is Coturnix House, Rake
Lane, Milford, Godalming, Surrey GU8 5AB
Printing
Advent Colour Ltd., Unit 1, Crown Way,
Walworth Industrial Estate
Andover, Hampshire SP10 5LU.
Responsibility for Constructional
Projects and Software
Every effort is made to ensure that the technicaland constructional articles published in thisQuarterly are correct. However, the ultimate
responsibility is with the reader to ensure thesafety of constructions and for any interfacingwith other equipment. GEO cannot accept
liability for shortcomings in any publisheddesign or any constructions carried out bymembers or other third parties.
Copyright GEO © 2006
The contents of this Quarterly remain theintellectual property of the Group for Earth
Observation Ltd. and its contributors. Copyingof text or images, either from the printed
Quarterly or from any electronically stored
source, is forbidden without permission from theeditor.

GEO Quarterly No 11Group for Earth Observation

September 2006

Francis BellA New Member of the GEO TeamDavid Simmons has formally agreed to join
GEO’s management team and we areconfident that he will be a great asset toour group. Many members will alreadyhave met David because he has attended
all our Leicester events where he has beenconspicuous giving demonstrations, on one
occasion, fitting hardware into a newcomputer and loading the software to set
up a running EUMETCast system inside
30 minutes. Last April, he demonstrated theextraordinary data rates coming fromHot Bird-6. David has appeared inphotographs in several GEO Quarterlies.

Shop hardware. Most importantly, we talked to
the visitors and, as last year, we estimated thenumber coming to our stand to be about 200.

A busy GEO stand at Kempton, showing thewide age range of visitors attending
We did take in some GEO membershiprenewals but the most important factor was theinteraction with our visitors. Secretaries of two
different clubs asked if they could have extra
literature for their clubs and of course theirrequests were fulfilled. Almost all the posters,
bearing images of the Earth, were taken. I
remember two children, not related I think,
who both said: ‘These pictures would looksuper on my bedroom wall’. Surely no better
use for them!
David Simmons talking to visitors to the
GEO stand at Kempton last March

GEO plans to be at Kempton again in
November. Do come and visit us if you can.

AMSAT Colloquium
David G1MAL has been involved inamateur radio for about 20 years. He ismembership secretary for the TCARC andplays an active role in the local 70 cm
repeater group GB3GF. He supports GEO
at the Kempton rallies and the AMSAT
colloquium in Guildford.
We extend a warm, formal welcome toDavid. He has said that he would try to fulfil
a technical role, mainly on the hardware
side. David who lives in Surrey may becontacted by email at:
g1mal@btinternet.com or tech@geo-web.org.uk

Kempton Rally
The South London Amateur Radio andComputer Rally is held at Kempton where, on
May 7, 2006, GEO attended for a second time.
We had a double stand and also resourcefully
made use of existing shelving and extra floor
space under a window. From a dish positioned
just outside this window we ran live
EUMETCast signals to the stand all day, plus
recorded images. EUMETSAT as usual had
provided us with literature: both technical andposters and we displayed some of our GEO

2

I have just returned from the AMSAT
colloquium in Guildford. GEO was invited togive a presentation during the three-day
meeting at Surrey University and I made abrief presentation relating to the background of
GEO. David Taylor was also present andbrought us all up to date with the latest
weather satellite news. I hope that a fullerreport with photographs will appear in our next
Quarterly.
In preparation for the AMSAT meeting I had adiscussion with some members of GEO's
management team asking what I could reportin relation to GEO's achievements in the brief
two and a half years of our existence. The
answers impressed me:
1 The production of a quality quarterly
publication—recognising the skills of theeditor and contributors
2 An established good relationship with our
national Meteorological Office who allow a
EUMETCast receiving licence in the UK
without a fee. This precedent was
successfully taken up by our Dutch friends.
This license policy has now cascaded
across Europe, and countries who used tocharge for a receiving licence now in manycases allow the license free of charge

www.geo-web.org.uk

3 A friendly and informed relationship withEUMETSAT and NOAA. These
organisations know about GEO and ourinternational membership. An example
here would be NOAA's knowledge ofproblems in the UK with reception of
NOAA 18. They changed the APT downlink
frequency to reduce interference problems.
It has now been restored to the originalplanned frequency but as a gesture of
goodwill it's difficult to think of anything
more responsive than changing a satellite
frequency
4 A busy web site, a busy shop and a usergroup forum providing advice on technicalissues and software from our membership.
Not bad in two and a half years. The above ismore or less what I said at the AMSAT
meeting.

Renewals
Please try to renew your membership on timeotherwise it makes work for an already busy
team. If you do not wish to renew that's fine,but by default don't just forget your renewal.
Two members have recently been in touchwith me, interestingly, making almost the same
point. They remarked that our hobby haschanged from the pioneering stage in which
weather satellite enthusiasts engaged in the
1970s, 1980s and 1990s, to a morecommercial dimension today. Perhaps an
aspect of this argument is true but this has tobe set against a long and distinguishedtradition within the amateur radio and satellite
community to push back the frontiers of what
is technically possible. Long may this continue.
However, numerically, we do need a healthy
membership to maintain our shared skills andtalent within our group.

If you remember from our last issue, I asked
the question: “How many European or North
African country outlines can you see fromweather satellites?”
My answer is two. Iceland and Malta. I ruled
out Cyprus because it is politically divided.
Within contiguous mainland Europe I cannot
see any complete country outlines. Of course
major rivers and mountains are visible fromweather satellites but nowhere do theseenclose a complete country. The point of thequestion relates to the ephemeral nature of acountry: we all share the same planet but
countries seem to be more dynamic.
If anybody wishes to contribute to this topic
please send me an e-mail or letter.

September 2006

Group for Earth Observation

GEO Quarterly No 11

Future GEO Events
GEO is planning to be at the Kempton Park
amateur radio and computer rally in SW
London, on Sunday 19th November 2006.
This will be the third time that GEO has run astand at this event.
Our own events for 2007 are in the planningstage. It has been suggested that we move our
symposium from Leicester, where we havebeen for the last three years, to a location in
the SE of England - perhaps Guildford. The
date will be planned to avoid any public holiday
weekend.
GEO has been invited to visit EUMETSAT's
headquarters in Darmstadt. This is an
opportunity which we will not miss.
Arrangements still have to be made but a datesometime during June or July 2007 looks
promising, again avoiding public holidays.
Details of our events will be published on our
web site and in the Quarterly as soon as they
are firmly established.
My thanks to GEO's friendly and talented
membership for contributing to our hobby.
Don't forget: if you have any experiences
which you can share with us, any text or
photographs they are always welcome.

Swallow This!
Now I don't suppose anybody will beinterested, but that will not stop me. The familyof swallows which I photographed on my VHF
aerial and which were featured in GEO Q8 did

After 3 years in post, Nigel Evans plans
to stand down as GEO Membership
Secretary at the end of this year.

return this year. They built a new nest within a
few centimetres of the previous one and reared
four of five fledglings.
Two of these were very lucky! They fell out of
the nest! I was privileged to find them andgentlly pick them up and return them to theirnest—and they survived.
How these birds manage to navigate aroundthe world is a mystery to me. Celestial,
terrestrial and magnetic I guess. They certainly

Les Hamilton has combined the roles ofPrincipal Feature Writer with both Editor
and Make-up Editor since GEO first
appeared. He now looks to take a wellearned break.

do more Earth observation than I do. Me: I
don't even know what GPS stand for!

New Editor and Membership Secretary
Disappointingly, I have had no offers from ourmembership regarding the posts of Editor andMembership Secretary. These two members of
the GEO Management Team have given
substantial warning that they wish to step downfrom what can be demanding posts toconcentrate their own interests.

David Taylor submitted this segment from the 06:15 UT Meteosat-8 HRV image on July 27
where the low sun angle gives an alsost 3D appearance to the large Atlantic depression.
Image © EUMETSAT 2006

www.geo-web.org.uk

3

GEO Quarterly No 11Group for Earth Observation

appeared as light ‘banding’ on
images when the satellite was at
a lower elevation. But one
receiver, the Dartcom module,
showed no interference at all.
Antenna Experiments
It was at this time, using aturnstile antenna, that I
accidentally noticed a reduction
in pager breakthrough could beachieved on some receivers byrotating the turnstile slightly, sothat the relationship of theantenna rods to the direction of
the paging transmitter changed.

John Tellick
Living in SW London, I havebeen plagued with pager
interference to polar orbiting
satellite APT ever since paging
services around 138 MHz
became operational in the early
1990’s. Pager transmitter sites
are normally spaced 18 km
apart, but more densely in urban
areas where buildings reduce
the effective reception area.
I have three nearby pager
transmitter sites, one just threequarters of a mile away, emitting
100 W on 137.975 MHz andother sites just a couple milesaway.
I long ago gave up polar orbiting
reception owing to theinterference, as my maininterest was the Sahara and theArctic. I used to receive noisefree imaging from AOS to LOS
using a beam antenna on arotator and a turnstile mounted
on the roof. But with the adventof wide-area paging channels
around 138 MHz in the UK,obtaining even the overhead
sections of passes on somefrequencies without interference
was a bonus.
The distant imaging ofMeteor 3-05, which had a higher
orbit than NOAA satellites,
therefore gave me extended
coverage N and S well into the
Arctic and southern Sahara
while its higher APT resolution(around 2 km) gave superb
images of these distantlocations.
But living in a bad paging
interference area is useful forinvestigating APT receiversusceptibility to interference.
New Frequencies
NOAA-N and NOAA-N prime,
the two final NOAA APT/HRPT
satellites, use one or other of
two new frequencies,
137.9125 MHz and 137.10 MHz.
The new European MetOp

4

series of satellites will all use
137.10 MHz for their digital
LRPT. Since I had suffered frompager interference to the Meteor
3-5 on137.85 MHz, I initiallyassumed that trying to receive
NOAA-18, would be a waste oftime.
Nevertheless, when NOAA-18
started transmitting on the upper
new frequency, widespread
pager interference was reported
from across the UK in a survey
undertaken by two GEO
members [1]. I set out todetermine what the possible
interference situation would be
like using an assortment of APT
receivers—a Proscan, a
RIG/Dartcom module receiverwith EPROM tuning, an RX2, a
Gola, an R2FX and a Vierling.

Following a suggestion by a
GEO member, I’d previously
done some tests using ferrite
rings and cores around thephasing harness and downleadof the turnstile antenna butthese appeared to make little if
any difference to my highinterference levels. I was also
told that a good earth rod
should help reduce interference.
My receivers were duly earthed
to a metal rotary clothes line
spike embedded in damp soil on
my lawn but again this didn’t
reduce the interference.

Of the six receivers tested, threewere ‘flattened’ by my local
137.975 MHz pager and proved
to be incapable of producing
satellite images; two of thesereceivers also suffered frompager interference problems at
lower frequencies.
Two other receivers, the RX2
and Vierling, experienced only
slight pager interference, which

vertically polarised.
Next I tested a QFH which hassome vertical components in its
construction, and which I foundto be more prone to pager pickup. This also demonstrated
some reduction of pager pick-up
by rotating it – albeit very muchless so than the turnstile.
There was of course thepossibility that the effects I was
experiencing might be due toreflection of pager signals fromsomething in myneighbourhood, so I should
moved the antenna to a newlocation to see if the same
phenomenon occurred. In theevent there was no difference: a
360° rotation still produced
identical pager nulls and peaksof the same intensity. I repeatedthe experiment with a turnstile
antenna from a different
manufacturer, and once more
the results were identical.
But how much reduction in
pager pick-up was I obtaining byrotating the antenna?
I consulted Dartcom Electronics
who kindly loaned me a
precision switchable attenuator.
By matching meter readings,
with the attenuator in-line on
maximum pager pick-up
antenna orientation, and not inline on pager null orientation,
gave a figure of 35 dB+
difference between peak andnull signal levels at the same
frequency just by rotating theantenna by a quarter-turn.

Receiver Experiments
Since the squirrels that live inthe trees at the bottom of mygarden had long ago chewed
through the cables from my roof
mounted antenna and beam, I
set up a turnstile antenna in thegarden atop a 16-foot pole.
Not having any test gear, my
experiments were quite ‘nontechnical’: the receivers either
demonstrated pager
breakthrough at 137.91 MHz(the nearest most could tune to.the NOAA-18 frequency) or
they didn’t. This was initiallydone by listening for pager
break-through this under zero
APT signal conditions (i.e. nosatellite within range).

September 2006

Although rather crude and nontechnical, this experimentdemonstrated a staggering
reduction in pager signal pick-up
by merely rotating the antenna. As
to what is actually happening here,
I don’t know, and would welcome
any suggestions.

The pole-mounted turnstile

Using my Dartcom module
receiver, I tuned to 137.94 MHz
where the pager signal started
to break through strongly,
reaching close to maximum on
my signal level meter. Turning
the antenna slowly through 360°
produced two deep, sharp nulls
and two broad high peaks inpager pick-up, which clearly
depended on the horizontal
orientation of the antenna
elements to the direction of thepaging transmitter site. Pager
transmissions are, of course,

www.geo-web.org.uk

In practical terms this means thatcertain receivers (the RX2 and theVierling, which had previously
shown slight banding) were nolonger affected by pager
interference.

Postscript
With all MetOp satellites using
137.10 MHz, NOAA may
eventually have to utilise 137.9125
MHz again for APT transmission.
In that case, pager interference
could again pose a problem forsome users.

Reference
1 NOAA-18 Reception andPagers, GEO Quarterly No 7,
page 11, September 2005

September 2006

Group for Earth Observation

GEO Quarterly No 11

Ferdinand Valk
By the time this article reaches you, theAtlantic Hurricane Season should be wellunder way and those of us receiving
EUMETCast will already have sifted throughmany Meteosat and GOES images—and eventhrough AVHRR material—to see with ourown eyes the impressive behaviour of thesemonster storms. Not everybody, however, isfully aware of what a hurricane actually is,
how it forms and from where it draws its
enormous power.
The purpose of this article is to provide someinsight into these energetic weather
phenomena, commonly referred to as Tropical
Cyclones.
What exactly is a Tropical Cyclone?
Let’s start out with a definition:
A tropical cyclone is a storm system with aclosed circulation around a low pressure
centre that is driven by heat energy.

Figure 1 - Basins of Tropical Cyclone Formation

With this rather simple definition in hand we
immediately recognise three important aspects:• they form in the tropics,• are cyclonic in nature,• and are heat engines.
Three types of tropical cyclone can be
distinguished depending on the windspeeds
reached:1 A Tropical Depression, which is anorganised system of clouds andthunderstorms that, as a whole, alreadypossesses a distinct surface circulation.
The maximum sustained wind speed isless than 17 m/s. The depression has noorganised overall spiral shape and no eye.
Again, as the name implies, it is a
depression in a tropical region. They areplentiful, can be inconvenient, but seldom
cause disruption of daily life.
2 A Tropical Storm, which is an organised
system of strong thunderstorms with apronounced surface circulation andmaximum sustained winds between
17 and 32 m/s. Although a distinctive
cyclonic shape starts to form, an eye isusually not present. It is common practicein most regions in the world to identify
the Tropical Storm with a name ornumber at this stage of its formation, .
3 Hurricane, Typhoon or Cyclone. Once a
tropical storm system has reached an
intensity such that it produces sustained
wind speeds greater than 33 m/s(118 km/h), we no longer call it a tropicalstorm but a hurricane, a typhoon or just a
cyclone, depending on the region in which
it occurs. At this stage, a strong spiralshape has formed and we can normally
clearly recognise an eye.

Figure 2 - Global Ocean Surface Currents

Figure 3 - Atmospheric Belts

There are seven regions along theequator where Tropical Cyclones of thethird type form (figure 1). Those thatform within the Tropic of Cancer, east
and west of Central America, arecalled Hurricanes while all those thatform in the Pacific, north of theequator and west of Hawaii, arewww.geo-web.org.uk

labelled Typhoons. All other Tropical
Cyclones of the third type are simply
referred to as ‘Cyclones’. These include
tropical cyclones occurring east andwest of India, all those that form southof the equator in the Indian Ocean andthose to both the northwest andnortheast of Australia.

5

GEO Quarterly No 11Group for Earth Observation

The same figure also shows that there are regions in the Tropics
where, apparently, no cyclone formation takes place. Largeparts of the Pacific Ocean south of the Equator, and the entire
Atlantic Ocean south of the Equator, seem to lack the conditions
for cyclone formation. The reason for this is reflected in figure 2
where the temperatures of the major ocean currents have beenplotted (red is warm and purple is cold) as well as the flow
direction of the surface currents.
Along the western South American coast we find the Humboldt
stream, a cold upwelling current that causes the waters near
the equator to be far too cold to trigger tropical cyclone
formation. Also, the waters flowing along the West African
coasts of Namibia and Angola in the Benguela current are very
frigid, due to their Antarctic origin. The low surface
temperatures are not conducive to the formation of a tropical
cyclone.
Not surprisingly, the basins associated with Cyclone formation
coincide largely with the areas shown in red in the image. It is
important to note, however, that the figure is drawn for
northern hemisphere summertime. During winter, the region ofwarm ocean surface waters moves south, explaining theseasonal nature of cyclone formation.
Preconditions for the Formation of Tropical Cyclones
Tropical Cyclones can only form when a number ofenvironmental conditions are met. First of all, as can beunderstood from figure 2, the ocean water temperature should behigh. A minimum temperature of 26.5°C is required and thatvalue should extend down to a depth of at least 50 meters. The
reasons for this are twofold: waters of this temperature cause
enough instability in the overlying atmosphere to sustain
convection and thunderstorm systems, and on the other hand
the warm waters form the reservoir of energy on which thecyclone feeds.
A second precondition is that the air temperature should bedecreasing quite rapidly with increasing altitude. The quicker
the air cools down the greater the rate at which latent heat(energy stored in water vapour) is released from theatmosphere. The principle behind this is that, when air
saturated with water vapour gets cooled down, the water
vapour transitions to a liquid (condenses). The amount ofenergy released during the transition from vapour to liquid is aphysical property of the substance in question. For water this isabout 2240 kJ/kg of water produced—about five times theenergy needed to heat water from 0 to 100°C. If we calculate thetotal number of kilograms of water produced in an active
hurricane it becomes apparent that the quantity of latentenergy available in the water vapour must be enormous.
Scientists at the National Centre for Atmospheric Research(Boulder, Colorado) have estimated that the rate at which ahurricane releases heat energy is of the order of 100 to 200
terawatt. And all of this is green energy. By comparison, thetotal energy production capacity of the whole world is estimatedat one terawatt.
Note: one terawatt = one million megawatts.
High humidity, especially in the lower-to-middle troposphere, isanother requirement. When there is a significant amount ofmoisture in the atmosphere conditions are more favourable forthe development of disturbances. And, as all things big start out
small, the atmospheric disturbance is at the root of any major
tropical cyclone. For clarity of definition I mention here that thetroposphere is the lowermost portion of the atmosphere; it
extends from the surface up to the tropopause, where thestratosphere begins. The extent of the troposphere varies
around the globe but is greatest in the tropics, reaching up to
about 16 kilometres, and smallest at the poles where thetropopause starts at around 8 km above the surface.
Low Wind Shear. In the definition of a Tropical Cyclone
provided at the beginning of the article, mention was made of a6

September 2006

closed circulation pattern around a low pressure centre. When
there are high winds passing the region of closed circulation
with a different tangent (not necessarily at the sameatmospheric level), wind shear will disrupt the required
convection in a cyclonic system which then loses its coherence.
Conditions that are conducive to hurricane formation include a
troposphere in which wind shear is virtually absent.
Source of Bad Weather. Again, for a weather system to grow toimpressive proportions it has to have originated from somethingsmall. It is therefore not surprising that a system of disturbed
weather must already be in place, and that that system shouldhave some sort of circulation as well as a low pressure centre
that can serve as the catalyst for cyclone formation and forrotation.

The Coriolis Effect
The last in the list of requirements has to do with a minimum
distance from the Equator. In this context, two aspects are
relevant: the Inter-tropical Convergence Zone, a low pressure
belt around the Equator caused by the constant updraft ofwarm air, and the Coriolis force. As the world turns around its
axis, the rotational movement influences the motion of both theatmosphere and large bodies of water via the so-called Coriolis
force. The strength of this force is greatest in the polar regions,because there, the surface of the Earth is at right angles to theaxis of rotation; it is weakest near the equator because there thesurface of the Earth is parallel with the axis of rotation. If the
Earth were not rotating, air would flow directly into the lowpressure belt (towards the equator), but as the Earth isspinning, the Coriolis force causes that air to be deviated and totravel around the low pressure centre. We have seen thatrotation is a prime ingredient in cyclone formation. The factthat the Coriolis force can impart considerable rotational
momentum to a forming cyclone makes it understandable thathurricanes do not form at or very near to the equator, wherethat force is weakest. It needs to be sufficiently distant from theequator to be strong enough to deflect winds blowing into thelow pressure centre. In practice this is at a distance of 500 km
or more from the equator. It is the Coriolis force that is
responsible for the direction of rotation of both air and water
masses on earth: cyclonic or anti-clockwise in the northernhemisphere, anti-cyclonic or clockwise in the southernhemisphere.

Setting the StageAll of the aforementioned variables need to be in place
simultaneously for a tropical storm to attain hurricane
proportions. However, we still need to set the stage upon which
the performance is going to take place.
This stage is well depicted in figure 3. Starting out from theequator we first encounter the Inter-Tropical Convergence Zone,
a belt of low pressure that girdles the Earth. The Tropics ofCancer and Capricorn are both home to a belt of subtropicalhigh pressure, bordering winds with a fixed westward
orientation, the Trade Winds or Tropical Easterlies. At higher
latitudes, outside the Tropics, we find in both hemispheres arather wide band of principally eastward flowing air, the MidLatitude Westerlies, which is bordered on one side by thesubtropical high (30°) and on the other by a belt of sub polar low(60°).
All these belts are organised parallel with the equator. One
more essential actor in the show is the Hadley Cell. This isessentially a global air transportation system that moves warm
air away from the Tropics to higher latitudes and colder air
away from the higher latitudes back towards the Tropics.
Finally, the Tropical Wave illustrated in figure 3 is the source ofthe bad weather I mentioned earlier under ‘Preconditions for
Hurricane Formation’.
Now that the stage is set, the actors identified and all props areavailable, we can try to attend the show itself. In the example

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September 2006

below I have considered events in the
Atlantic Basin.
The Life and Times of a Hurricane
The proverbial butterfly has been busy
flapping its wings in sunny western
India, setting off a tiny rhythmic local
oscillation in a pocket of air; this acts as
an amplifier and vehicle for the
propagation of a signal destined for
greater things. Left in the hands ofMother Nature, chaos theory takes over,transforming the flapping into an area oflow pressure, also called a Tropical Wave;
this travels westward with the prevailing
air currents over the warm waters of the
Indian Ocean. The funnel formed by the
Gulf of Aden directs the wind flow
straight into the Ethiopian
highlands where the interplay
between warm moist air
brought in from the Indian
Ocean and the cold air fromthe highlands causes theformation of strong gusty
winds and thunderstorms
with heavy rain.
By this time the Tropical
Wave has transformed into a
Tropical Disturbance, which
in turn crosses the full widthof the continent of Africa,
increasing in intensity but
remaining structurally unchanged. Whena Tropical Disturbance persists for morethan 24 hours and increases in intensity,
as is the case in our example, it isupgraded to the level of a Tropical
Depression. During its crossing of thecontinent the Tropical disturbance also
obtains a more pronounced Coriolis
driven rotational motion. Once it hasreached the west coast, the system isblown off Africa into the Atlantic Ocean,well within the region of persistent low
we call the Inter Tropical Convergence
Zone (figures 5-8).
Once the depression has entered theConvergence Zone, it arrives in an area
where there is a constant influx of moist
air. The Hadley Cell mechanism that isalways at work causes an updraft of thewarm moist air towards the colder upper
air. When the cooling is rapid enough thewarm water-vapour condenses on a large
scale, thus releasing huge quantities oflatent heat energy (see the explanation
earlier under ‘Preconditions’).
The energy that is freed in thecondensation process is used in two
different ways. Part of the heat energy isconverted into kinetic energy whichcauses the wind speed to increase. It
should be remembered that therotation—in our example anticlockwise—is already present in thesystem. Those higher wind speeds andthe consequential lower pressure resultin the capacity to suck in much morewarm saturated air, driving storm
intensity up in the process. AnotherGroup for Earth Observation

substantial part of the energy freed up by
condensation goes towards increasing theheight of the storm clouds. The fact thatthe heights of the clouds increase meansthat the system reaches into a colder
environment. It also means that the total
surface exposed to the cold condensing
environment will increase and thus thecapacity for condensation is greatly
enhanced.
Eventually, the amount of energy within
the cyclonic system may increase to apoint where enough energy is released for
it to become self-sustaining. This positive
feedback loop ensures that the systemremains self-supporting until one or moreof the input requirements starts failing.

Figure 4 - Rain Bands

Left undisturbed in the positive feedback
loop, the Tropical Cyclone progresses
naturally through the stages from
Tropical Depression and Tropical Storm
to a real hurricane. Wind speeds within
the system keep increasing, as do height,
diameter and the rate of rotation. The
pressure at the centre of rotation drops
dramatically and the fast rotation of thesystem causes an eye to form. Althoughwind speeds within a hurricane system
can reach values from 120 to over
250 kph, the total hurricane complex infact flows with the prevailing windcurrents at a speed that is often
comparable with that of a cyclist.
At this stage, when we have a fullfledged hurricane in place, a cross sectionof the system would look something likefigure 4.
We recognise the eye chimney in the
middle, the main lobes and a number ofside lobes on each side. Arrow 1
represents the influx of air which, by
passing over the warm ocean surface, hasabsorbed great quantities of moisture. As
this hot air is loaded with water vapour
it rises up the centre (arrow 2) to thelevel where condensation takes place.
The faster the updraft of this air the
more explosive the release of latent heat.
The energy released by condensation
speeds up the wind movement andincreases the height and volume of thecloud column. At point 3 the ceiling of thetroposphere has been reached and the airstops climbing further. This typicallywww.geo-web.org.uk

GEO Quarterly No 11

occurs at an altitude of some 16 km. By
this stage the clouds have cooled down
considerably, and as indicated byarrow 4, drop back to sea level.
It should be understood that, because of
the very low air pressure at the core of
the hurricane, the ceiling of thetroposphere is sucked in as it were,
resulting in an influx of cold air from thetropopause into the chimney. This is
depicted at point 5. This cold air passes
downward through the chimney along theeyewall to point 6, helping to cool theocean surface.
The Eye and Eyewall
There is something more to say about theeye and eyewall. Due to therotation of the whole complex,
the updraft of warm air forms
an upward spiral, right up to
the top of the hurricane. Thisspiral forms the eyewall of thehurricane and it is the region
with the strongest winds, thetallest clouds and the heaviest
precipitation. In really strong
tropical cyclones the eyewall
wraps completely around theupper portion of the eye of thestorm. The greater the storm
intensity the tighter the
eyewall winds and consequently
the more the storm speeds up. It is thesame process by which a pirouetting ice
skater speeds up when pulling the arms
in.
Because thunderstorm activity also takes
place outside the eyewall region thisprocess of speeding up has a natural
maximum limit. At a point when theeyewall and area of strongest winds has
contracted to a diameter of between 8
and 25 km, thunderstorm activity in the
periphery may become disassociated fromthe eyewall region and outer rain bands
may organise into an outer ring ofthunderstorms (an outer eyewall) thatslowly moves inward and robs the inner
eyewall of its necessary moisture andmomentum. Such an outer eyewall
typically forms some 80 km from thecentre of the storm.
During this phase, the hurricane
weakens, which means that the
maximum winds die off a bit and thecentral pressure rises. Eventually, theouter eyewall may replace the inner one
completely and the storm can then regain
its previous intensity or, in some cases,
become even stronger. This is called the
Eyewall Replacement Cycle, and is aphenomenon that may repeat itself
several times during the life of ahurricane, effectively placing an upper
limit to possible wind speeds. The
schematic overview in figure 4 also shows
the regions of heaviest precipitation orrain bands. The wider the hurricane
system, the more side lobes and hence
rain bands will be present.

7

GEO Quarterly No 11

Figure 5 - The Ethiopian highlands

Group for Earth Observation

Figure 6 - The complex crosses Africa
Figure 8 (left)
Over the Atlantic ocean

Figure 9 (right)
A 3D rain intensity graph by
the TRMM satellite

Figure 10 (below)
Hot towers in hurricane Ivan
Figures 5-8: Credit NASA
Figure 9: NASA/JAXA

8

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September 2006

Figure 7 - Arrival at the west CoastSeptember 2006

Group for Earth Observation

There is another quite remarkable aspect of very active
hurricanes which has to do with the rain intensity andconcentration throughout the storm complex. Since the launch ofNASA’s Tropical Rainfall Measuring Mission (TRMM), it has
become possible to study this in a detailed and structured way.
Figure 9 is a 3D product from TRMM (rather in the style of a
CAT scan) in which we see the distribution of rain within thecloud complex of hurricane Rita. The colour is a measure of thestorm’s rain intensity with red being most intense and blue least,
while the height of the each peak refers to the actual elevation of
the cloud column. In this true-to-reality graph, two spikes appear
in the rain structure. These spikes are termed Hot Towers andare in fact tall cumulonimbus clouds that, in the case of hurricane
Rita, reached an altitude of almost 20 km. The phenomenon has
a rather limited diameter when compared with the hurricane
itself and it is of quite short duration. Still, it is one of themechanisms by which the intensity of a tropical cyclone ismaintained or enhanced. This is, in itself, quite understandable,
because when, in a very short time, a huge column of hot wet air
soars to the very cold stratosphere, the resulting condensation
and release of energy must be truly explosive. This energy can dobut one thing: drive the hurricane to greater intensity.
Figure 10 shows an AVHRR image from hurricane Ivan taken atdaybreak on September 1, 2004. The very low angle of incoming
sunlight clearly demonstrates the presence of a significant
number of hot towers outside of the eye region. They are alreadystarting to form an independent ring (outer eyewall) that, at alater stage, will replace the inner eyewall. The occurrence of hot
towers is now being used as an accurate parameter in forecasting
the intensification of hurricanes.
Assessing Hurricane Intensity
It has always been very difficult to provide an objective measureof the force associated with a particular Tropical Cyclone. Even
today, classification is not commonly done outside the northeast
Pacific and western Atlantic. However, for these two regions,
Herbert Saffir developed a scale to classify them in accordancewith objective and measurable criteria (largely based on windspeeds and the typical damage associated with certain windspeed categories). Bob Simpson, working on behalf of insurancecompanies, realised that certain damage not directly attributable
to high winds remained unaddressed. This was the damage
inflicted by the surge of water that usually accompanies a heavy
storm. He incorporated this information into the scale, mainly tohave a measure for assessing inflicted damage more accurately.
The resulting Saffir-Simpson scale has since been widely adopted
within the Western World to classify all hurricane-force tropical
cyclones.
Saffir-Simpson
Category

Maximum sustained
wind speed(Herbert Saffir)

Minimum
surfacepressure

Storm surge(Bob Simpson)

m/s

kp h

millibar (mB)metres1

33-42

118-152>980

1.0 - 1.7

2

43-49

153-177979-965

1.8 - 2.6

3

50-58

178-209964-945

2.7 - 3.8

4

59-69

210-249944-920

3.9 - 5.6

5

70+

250+

<920

5.7+

GEO Quarterly No 11

Westerlies: It has been noted that the entire hurricane complex
drifts with the prevailing winds and currents. Such currents may
drive the hurricane out of the Tropics into the belt of westerly
winds, which may destroy its structure and/or drive it into colder
waters. In the first case the hurricane will hiccough and stop,whereas in the second, it loses its tropical characteristics andmay convert into an extra-tropical cyclone.
High wind shear: When a hurricane drifts into a region where
there is a strong higher level wind, wind shear takes the stability
out of the circulation pattern and the direction out of theconvection. The hurricane cannot then support itself any further.
Semi-stationary: When a hurricane remains in the same area of
ocean for too long, it draws heat from the ocean surface until
locally, there is no longer enough sufficiently warm water
available to feed it (remember: 26.5°C and 50 m deep). Again theheat engine will stop and the hurricane cannot survive.
Weakness: Even a hurricane can fall victim to another area oflow pressure and be consumed by it. Usually such a merger
causes disruption, resulting in a large area of non-cyclonic
thunderstorms. Of course, it may very well turn out to strengthen
the non-tropical system as a whole instead, but it still spells theend for the original hurricane.
Outer eyewall: The formation of an outer eyewall reduces theintensity of the hurricane. Such weakening is generally
temporary unless it meets other conditions such as I mentioned
above. This can then lead to its demise even when the otherconditions by themselves are of insufficient intensity to cause thedissipation.
CaveatThis article has focused exclusively on generic tropical cyclones
and the mechanisms involved in their creation and demise. It by
no means implies that this is the full story, as many unknowns
remain and many deviations from the standard description occur
in Nature.
Examples of Non-Standard Tropical Cyclones
Typhoon Vamei defied the Coriolis restriction when it appearedin the South China Sea a mere 1.5° north of the Equator. Veryspecific local conditions took over the function of the Coriolis
force. Cyclone Catarina was, in March 2004, the first everrecorded hurricane-force storm south of the equator in the
Atlantic ocean, in an area where the prevailing ocean surface
currents are normally too cold to allow hurricane formation.
Non Tropical Cyclones
Extra-tropical cyclones draw a portion of their energy from theevaporation and condensation of ocean water, and some throughhorizontal temperature gradients in the atmosphere. They occur
in-between tropical and mid-latitude cyclones. Many tropical
cyclones turn into extra-tropical ones at the end of their life cycle.
Extra-tropical storms seldom transition into tropical ones.
Subtropical cyclones, like their extra-tropical counterparts,
constitute an intermediate form between tropical and midlatitude cyclones. They are, however, mostly associated with theregion south of the Azores and the Mediterranean basin

Table 1 - The Saffir-Simpson Scale

The Demise of a Hurricane
I noted earlier that, as long as there are no changes to theconditions present once the hurricane is established, it willsustain itself ‘indefinitely’. Fortunately, the strict conditions
required for the formation of a hurricane are also instrumental toits stagnation and dissipation. This can be summarised asfollows:
Landfall: When the storm’s centre reaches land (i.e. the centreof the eye, not its edge) then no more moist air is fed from theocean surface into the system and thus the condensation motor
runs out of fuel and switches off.

Mid-latitude cyclones are driven by baroclinic processes, whichmeans that the temperature contrast between warm and cold air
masses is the driving process behind their energy influx. They
are found in the temperate regions (between the tropical andpolar regions) and occur above land as well as sea.
The sub-Arctic and sub-Antarctic systems are basically the sameas mid-latitude ones, but they occur at very high latitudes andinvolve very cold winds.
Acknowledgement
Thanks to Jonathan Valk for proofreading this article and for suggesting
helpful improvements.

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9

GEO Quarterly No 11Group for Earth Observation

September 2006

Les Hamilton
The image at the foot of this page,acquired by the NASA Terra satellite, isa prime example of a cloud pattern
known as a Ship Wave. Although thename might suggest otherwise, thisphenomenon does not owe its origin toany ship, unlike a ship trail [1]. Ship
waves are so named because of theirresemblance to the wake of a ship as it
moves through still water, an effectidentical with that observed downstream
from a duck swimming in a pond.

Figure 1 - A mallard trailing ‘ship waves’

The 250-metre resolution MODIS image
reproduced in figure 2 contains aparticularly well-developed ship wave tothe lee of Amsterdam Island in thesouthern Indian Ocean. Anotherparticularly good example of ship waves,this time emanating from the South
Sandwich Islands, appears opposite.
Kelvin ship waves, as these phenomena
are correctly termed in the sphere of fluid
dynamics, form a distinctive feathered
wave pattern within an envelope thatmakes a fixed angle of 19.5 degrees withthe direction of travel; they are named
after the physicist Lord Kelvin whoestablished the mathematics governing
their formation. Note that they arecompletely distinct from—and unrelated
to—the churned-up wake emanating froma ship’s propellors. Though originallydescribed in liquids, these wave patterns
can occur in any fluid, including Earth’s
atmosphere. The drawing in figure 3
illustrates a set of Kelvin waves trailingbehind a moving ship. The cloud patterns
in figure 2 resemble these waves very
closely, although in this instance it is thefluid itself (the atmosphere) that is inmotion and the waves derive from theobstructing effect of Amsterdam Island.
Cloud Patterns
Air is a fluid and, when wind encounters
an obstacle, it must move around andFigure 3 - Kelvin ship waves

Figure 4This aerial photograph shows actual Kelvinship waves trailing behind the USS John F
Kennedy and her escorts in the Arabian Gulf
Image: US Navy (Christian Eskelund)

Figure 2 - A MODIS image of Ship Waves induced by Amsterdam Island in the southern Indian Ocean on December 19, 2005
Image: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC

10

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Kelvin Ship Waves
Waves induced by the South Sandwich Islands in this 250-metre resolution MODIS image from NASA’
NASA’ s Terra satellite on September 18, 2003
Image: Jacques Descloitres, MODIS Rapid Response System

GEO Quarterly No 11Group for Earth Observation

September 2006

over it. This causes it to trail a wakethrough the atmosphere, very similar tothe one shown in figure 3. Everyone isfamiliar with the way in which ripples
crossing a pond cause floating objects tobob up and down. The air within a Kelvinship wave oscillates up and down inexactly the same manner.
Where the air is relatively dry thesewaves will remain invisible but, when air
oscillates in this manner as it must in a
Kelvin wave, it alternately cools at eachwave-crest and warms at each trough. In
air that is close to being saturated withwater vapour, cooling causes
condensation and cloud formation while
warming makes the cloud evaporate once
more, rendering the Kelvin wave visible
as a cloud pattern which repeats itself at
each wave crest.
Jan Mayen Island
The north Atlantic Jan Mayen Island canalso give rise to ship waves. The 2280
metre conical volcano Beerenberg
produced the cloud pattern shown infigure 4
The Crozet Archipelago
The appearance of ship waves is favoured
by the same general weather conditions
that produce the more familiar Von
Kármán vortices[2]: a low levelsubsidence temperature inversion above
a warm sea. In figure 5, dating from late2004, islands of the Crozet Archipelago in
the southern Indian Ocean havedisrupted air flow and formed both shipwaves and Van Kármán vortices[3].
In this particular instance the elevationof the obstructing islands is all-Figure 4 - Kelvin ship waves spreading from Jan Mayen island in the north Atlantic
NOAA-15 at 14:56 UT on January 25, 2000
Image: NOAA CLASS archive (www.class.noaa.gov)

important. Where the inversion occurs below the highest part of the obstructing island,as it does in the case of Île de l’Est (1090 m) at the eastern end of the group, thevertical oscillation of the cloud wakes is compromised because the air can no longer
flow over the obstruction. The consequence is that a series of eddies forms as air iscompelled to flow around the island, creating the familiar Von Kármán vortex street.
However, where the inversion lies well above the highest part of the obstruction, aswith Île aux Cochons (826 m) to the west of the archipelago, the air can flow freely
both around and over the island, resulting in the formation of ship waves.
References
1 GEO Quarterly No 6, page 28
2 GEO Quarterly No 2, page 46
3 http://www.weathersa.co.za/Pressroom/2005/2005Oct21ShipwaveCrozet.jsp

Figure 5 - A MODIS image showing both Kelvin ship waves and Van Karman vortices spreading from the
Crozet Archipelago in the Indian Ocean, viewed from NASA’s Aqua satellite on November 2, 2004.
Image: : Jacques Descloitres, MODIS Rapid Response System

12

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GEO Quarterly No 11Group for Earth Observation

September 2006

Arne van Belle
EUMETSAT’s recommended system consists of a dedicated PC
which receives EUMETCast data using the Tellicast client
software and then sends this data to a networked second PC forconversion into images and storage on disk. This means that you
need both PCs running 24 hours a day if you want up-to-date
images.
However, with the advent of the fast modern PC, it is now
possible to use a single PC to receive, decode and store images
and data. This setup is ideal, specially if you don’t want to receiveand decode 24 hours a day. But you do have to limit the load on
the system. Starting other demanding programs like
GeoSatSignal or a large animation will take so much of yoursystem resources away from the Tellicast client that you suffer
missing segments.
There are other disadvantages with a single PC

If the process PC has been switched off during the night and mostof the day it will take around 15 to 20 minutes to transfer all thereceived images and data to it (including the recent AVHRR trialdata). By prioritising the channel-12 north images, I can have an
up-to-date High Resolution Visual animation running only
5 minutes after booting up the process PC. If the process PC isswitched off, or if a previous transfer is in progress, the script will
halt.
Advantages• Any minor hiccough affecting Windows (which happens
now and then) is also likely to cause missing data,
specially if you have to reboot.
• Running your fast PC for 24 hours a day will cause a highenergy bill as fast PCs run at between 150 and 250 watt
nowadays.
• In the near future, EUMETCast will be extended toinclude high volumes of MetOp data.
• If you want to receive this data too, the performance ofyour single-PC setup might prove insufficient.
The Receive PC
An alternative to using a single high-performance PC is what I
call the ‘Semi 2-PC Setup’. This involves running an older, lesspowerful PC 24 hours per day to receive all data (currently I use
a 1 GHz Pentium-3 computer). This same PC also runs MSG
Data manager which decodes and stores the images. A RAM disk
is used to buffer the Tellicast file database, which not only eases
the load on the hard disk but also helps Tellicast to continue it’svital job at times when other programs are accessing it.
The Process PC
All your decoded images and data are transferred to a second,
faster, networked processing PC (this could be your normal
Internet/work computer) for all subsequent image browsing,viewing, processing and animating using programs likeMSG Animator and GeoSatSignal. This PC is only switched onwhen you actually need it and can also be used for lots of othertasks like photo or movie editing, surfing and so on. An
unexpected system halt or other mishap on this system will not
result in missing segments or lost data.
Transferring the Data
To make this setup work we need to move all decoded data fromthe receive PC to the process PC. I have written a simple scriptthat runs on the receive PC and which is started by MSG DataManager after every 15-minute cycle. The script checks whether
the process PC is ready to receive data and if so, moves all
decoded images and data to it. Folders are created on the fly sothat, in the end, you have exactly the same folder structure on
your process PC as if MSG Data manager were running on it too.

14

I run MSG Animator, GeoSatSignal and the AVHRR Manager on
the process PC. To automatically update the animation you haveto set ‘updates’ to 15 minutes as MSG Data Manager runs only on
the receive PC and cannot trigger an update in MSG Animator
over the network. Within 15 minutes of starting up the process
PC, data will be transferred.

• Because you move decoded images, not the raw data, thequantity of data that needs to be transferred over the
network is much reduced.
• The receive PC is not used for other tasks that could
interfere and runs remarkably stably.
I have run this setup using Windows 2000 since early April 2003
and the receive PC has never been halted unexpectedly or neededa forced reboot.
Disadvantages• You need network interfaces in both PC’s and a networkhub.
• If you do not have a network already, a simple network
cross-cable can be used to interconnect the two PCs (Cross
cables are now available from the GEO Shop).
The Script
Here are some details about the script I use to copy the images
from the receive PC to the process PC.
Microsoft offers the Robocopy command line utility. This is partof the Microsoft Windows resource kit and can be downloaded forfree. Robocopy stands for ‘Robust File Copy Utility’ and is used byMicrosoft to synchronise servers. Robocopy will automaticallyresume broken transfers and can be set up to throttle down to
reduce the load on disk and CPU. It comes with a 35-page manualthat explains all options in detail.
The Windows resource kit has to be installed on Windows XP or
Windows server 2003 first. Once installed, the Robocopy
command can be copied and also works on Windows 2000 and
NT4.
Before using my script you have to set the source and destination
once. You can tailor this script to your needs. Another useful
option could be to synchronise time on the receive PC.
A copy of the script and instructions are available at:www.geo-web.org.uk

http://www.satsignal.eu/software/msg_dm_pc2.zipSeptember 2006

Group for Earth Observation

This script actually converts an older PC into a ‘Set And Forget’
EUMETCast receive-and-decode server. Although I do have a
Keyboard/Video/Mouse switch to control my receive PC, I only
check signal strength now and then. It runs at 60 to 90 watt andruns fairly cool.
Requirements for the Receive PC• 1 GHz pentium-3 or better (current status receiving all
PID’s including the new AVHRR data and processing all
images except Meteosat-8 LRIT).
• At least 512 MB is required for MSG Data Manager but
more memory is recommended for the future EUMETCast
extensions.
• A 100 Mbit network interface card
• Crosslink cable to processing PC or a network switch/hub• Windows XP or Windows 2000. I prefer Windows 2000
because it uses less memory and runs more stably.
Optimising a PC for 24 hour use
A PC that needs to run stably for 24 hours a day needs ourattention:• We want it to run stably, for a lengthy period of time, withlow maintenance and cost.
• The average home PC is not designed to run continuously.
• Most hardware failures are caused by prolonged
overheating, so we need to keep it running cool.
• To save power and reduce heating, disconnect the CD-ROM
and diskette drive after installation of the system.
• If needed you can use the CD-ROM drive on yourprocessing PC by sharing it over the network.
• A bare-bones PC does take up less space but I prefer a
tower model as this can be modified more easily to run cooland with low noise.
• You need to monitor the temperatures of the CPU and hard
drive. If temperatures remain high (over 50° for the disk
and over 60° for the CPU), hardware failures are quite
likely within 2 years.
• Most mainboards and discs are equipped with onboard
temperature sensors; you only need to install software to
get a readout.
• DTEMP and MBM5 are two universal programs that canbe downloaded free.
• To ease the load on the disk use a RAM Disk to buffer the
Tellicast file database.
• If you use XP you need to exclude the RAM Disk fromsystem restore! See article on page 39.
• As the PC runs 24 hours we don’t want a lot of noise either.
• A quick way to solve this would be putting you PC in thefreezer and closing the door ! But this way you will run outof cooled beverages very quickly during summer.
Don’t try this at home as condensation
will ruin your system in the end.
So I opted for Case Modding.
• By improving airflow inside the case and mounting thehard disk at a better location, you can lower temperatures
drastically.
• Most PC cases are designed to look nice but not for cool
running.
• The air intake area at the front should be at least twice aslarge as the exhaust area at the back!
• If needed, drill additional holes in the front.
• With an increased airflow inside you can use passive
cooling for the chipset and CPU.
• You can use plastic or cardboard guides to force airflow
through the passive CPU cooler.
• To keep the noise and maintenance low, use large fans.
• Large sized fans (120 or 92 mm) run with lower rpm. They
not only give less whining noise, the bearings last much
longer and they transport more air ! Use vibration
dampening mounts to reduce fan noise.

GEO Quarterly No 11• To handle different load situations and varying ambient
temperatures efficiently I use a fan controller that
automatically adjusts fan speed according to the insidetemperature.
• Alternatively you can run a 12 V fan from 7 or 5 volts tolower noise level.
• Do not use fan grills that have sharp edges or block airflow.
Grills made up from round wire are the best and these also
provide good Radio Frequency Interference shielding.
With the rise of the Multimedia or Home Theatre PC there aregood low-noise fans and accessories available nowadays. I canrecommend the low noise fans from Glacial Tech called ‘silent
blade’, as these use nine specially formed blades and double ballbearings to give high airflow at low rpm. Other brands like SilenX
and Nexus also offer low-noise fans but are priced a bit higher.
• Don’t use a high performance graphics card as these use asmall fan. You do not need high graphics performance forthis purpose.
• By mounting the disk upright behind the front air intake,it gets a continuous flow of cold air. Point the electronics
board towards the incoming air and use rubber dampers or
grommets to isolate vibrations from the case.
• Using this setup I have disk temperatures that are only 5
to 10 degrees above room temperature.
• To further reduce noise and vibrations you can pad thelarger inside panels with carpeting tiles.
• The ‘woolly’ side effectively dampens high frequency noises.
• Use the type with a bitumen or rubber base and glue it to
the inside of the panel. This dampens any low frequency
vibrations.
• Do not use carpet tiles with a foam base as the glue will
dissolve the foam!
• Self adhesive dampening mats can be bought at computer
stores but come at a cost and are not as efficient at
dampening.
Maintenance• Do not forget to plan a ‘dust out’ maintenance at least half
yearly as too much dust will reduce cooling and raise
temperatures. Be very careful when using a vacuum
cleaner to dust out; never touch electronic components withthe hose as static build-up in the hose could jump over. Use
a clean paintbrush to loosen the dust and keep the vacuum
cleaner at a distance.
• The cheaper fans use sleeve bearings and these may run
dry after a year, emitting rumbling sounds or even seizing
up completely.
There is an easy fix to prolong the life of your fans. Remove
the sticky label. Most fans have a rubber cover underneathto seal the sleeve bearing. Apply 2 to 5 drops of motor oil tothe spindle bearing. Use Sellotape to seal the bearing coveragain. If done in time and, say, every two years, your fanswill run smoothly for ever.
• Power cuts are unavoidable. Uninterruptible power
supplies are cheap nowadays but they can only bridge shortinterruptions of up to 20 minutes. But you can set up yoursystem to help it recover better from a power failure. In the
BIOS, set ‘power state’ to ‘always on’. Now your PC will
reboot directly when power is restored.
• Windows2000 and XP can be set to boot automatically witha given username and password.
• Setup4PC and Tellicast should already start up
automatically.
• The next step is to add the parameter ‘-Start’ to your MSG
Data Manager link and place a copy of this link in the‘Startup’ group.
• Never choose ‘reconnect at startup’ when you map a
network drive on the receive PC as this will halt windows
at reboot !

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GEO Quarterly No 11Group for Earth Observation

September 2006

Above is a colour composite image utilising the full ‘north’ segment provided by Dundee Satellite Receiving Station. At lower left is a segment fromthis image at full resolution while at lower right is a full resolution section from the ‘south’ image showing Namibia and part of South Africa.
All images © EUMETSAT 2006, NERC Satellite Receiving Station, University of Dundee - Processing in GeoSatSignal-6 by David Taylor

16

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September 2006

Group for Earth Observation

GEO Quarterly No 11

Les Hamilton and David Taylor
Registering
GEO readers who do not have access to EUMETCast may beinterested to learn that all ‘essential’ 6-hourly MSG images are now
available for download from Dundee Satellite Receiving Station. To
gain free access to these, all that is required is that you visit
http://www.sat.dundee.ac.uk

and click the ‘Register for free images’ button. Supply a username(your own choice) along with your e-mail address and you will be
forwarded a password which you can then use to access the MSG
images, which are archived at
http://www.sat.dundee.ac.uk/abin/geobrowse

be downloaded as small(1250 pixels2), medium (2500 pixels2)
and large (5000 pixels2) sizes, with orwithout a grid overlay (country
outlines); the IR and WV channel
images are half these heights andwidths.The archive dates back to (andoffers 3-hourly images prior to) June 8
2006, since when only 6-hourly images
are available. The Indian Ocean Data Coverage (IODC) archive
contains only the previous 30 days worth of 6-hourly images.
GOES East and West
There are three download options, consisting of the high resolution
visible, infrared and water vapour images. Both visible and infrared
channels may be downloaded in small (704x812 pixels), medium(1408x1624 pixels) and large(2816x3248 pixels) sizes, with orwithout a grid overlay (country outlines); the WV channel images
come at 50% width and height. The archive consists of theprevious 30 days worth of 3-hourly images.
MTSAT
Three channels are available at present, channel-1 (visible),channel-4 (infrared) and channel-6 (water vapour). All may be
downloaded as small (640x696 pixels), medium(1280x1392 pixels)
and large(2560x2784 pixels) sizes, without gridding only. The
archive includes the previous 30 days worth of 3-hourly images.
Image Quality
All the images are provided in ‘a slightly degraded JPEG format’(histogram equalised), so cannot be used for accurate calibration
purposes like the directly received EUMETCast data. Also, as the
MSG data are available only every six hours, these images are notreally suitable for animation purposes.

Images Available
As is clear from the screen-shot of the web page above, you will
also have access to relayed imagery from the first generation
Meteosat-7 (6-hourly), Indian Ocean Data Coverage (IODC),
currently from Meteosat-5 (6-hourly), GOES-E and GOES-W(3-hourly) and MTSAT-1R (3-hourly).
MSG
In all, 14 download options are provided. These consist of the fullrange of 11 normal resolution channels, 2 HRV options (‘north’ and‘south’) plus an RGB321 colour composite. All are available assmall (928 pixels2), medium(1856 pixels2) and large(3712 pixels2)
sizes, with or without a grid overlay (country outlines). There is anarchive available stretching back to noon on August 11, 2004.
Meteosat 7 and Indian Ocean Data Coverage (Meteosat 5)
There are three download options, consisting of high resolution
visible, infrared and water vapour images. The visible channel may

Nevertheless, the still images are of excellent quality and should
appeal to anyone without direct EUMETCast access—whether forcost or antenna planning permission reasons. The latest versionsof David Taylor’s software have been updated to handle theDundee data: the free AutoGet program can download them on to
your PC while GeoSatSignal-6 can process them into spectacularfalse-colour images.
As a sample of what can be done, David Taylor has kindly supplied
the false-colour images reproduced on page 16 and on the insideback cover of this issue. All were processed using GeoSatSignal 6
using data downloaded from Dundee, by combining a highresolution visible image from channel-12 with a thermal image fromchannel-9. Note that Dundee splits the channel-12 HRV data into
‘north’ and ‘south’ regions.
The Europe image on page 16 shows the full ‘north’ segment(though inevitably at reduced scale: the full image measures 5568
x 2784 pixels and would stretch across three pages of GEO
Quarterly). A full size clip containing Britain, France and Spain
serves to illustrate the resolution that is available.
The inside back cover of this issue shows the full ‘south’ region at
reduced scale while the lower right-hand image on page 16 is a fullsize clip depicting part of southern Africa.

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GEO Quarterly No 11Group for Earth Observation

September 2006

Peter WakelinWith the recent successful CloudSat/CALIPSO launch, theambitious A-Train project has come a step closer to realisation.
The A-Train Constellation
When completed, the constellation will comprise six quite
different spacraft, in co-planar orbits, carrying a wide range ofcomplementary instruments to study many aspects of theatmosphere, clouds and weather. For the first time, nearsimultaneous measurements from six satellites passing within a
few minutes will be possible. The five satellites of theconstellation now in orbit are Aqua, which is followed by
CloudSat, then CALIPSO, PARASOL and Aura. Aura trails
about eight minutes behind Aqua. Still to be launched is OCO,
which will lead the train some 15 minutes ahead of Aqua.
Launch is due in early 2008.
The Orbit
Each of the satellites has the ability to manoeuvre occasionallyto maintain the required ground track and spacecraft
separation. The 705 km circular orbit requires an inclination
close to 98.237 degrees to maintain sun-synchronism and theatmospheric drag effects have to be compensated for to ensure
the ground track repeats precisely after 233 orbits to match the
WRS-2 grid whereby orbits are separated by 172 km at theequator. The World Reference System-2 Grid was developed
many years ago to facilitate regular sampling patterns byremote sensors in the Landsat programme. The orbit plane isoriented so that the satellites cross the equator, in a northbounddirection, at about 13.30 local time, which is several hours later
than the mid-morning plane favoured for most Earth-imaging
spacecraft.
Aqua
Currently the leader in the A-Train, Aqua was launched in May
2004 and, initially, was known as EOS PM as it was the the‘afternoon’ satellite in the NASA-centred international Earth
Observing System (EOS). Aqua, the Latin word for water, is anappropriate name as the mission is gathering large amounts ofdata about the Earth’s water cycle, including ocean evaporation,
atmospheric water vapour, precipitation, clouds, soil moistureand ice on both land and sea. Aerosols, vegetation cover on landand phytoplankton and dissolved organic matter in the oceans
are also being routinely measured, as are temperatures of theair, the land and ocean surfaces.

18

Aqua's instruments
Credit: NASA

Two of the instruments on Aqua will be familiar to readers; theAdvanced Microwave Sounding Unit (AMSU-A) is also on board
the NOAA weather satellites (since NOAA 15) and measurestemperature profiles in the high atmosphere. The Moderate
Resolution Imaging Spectroradiometer (MODIS) is also aboard
NASA’s Terra satellite.
Also carried are the Humidity Sounder for Brazil (HSB)
developed by the Brazilian National Institute for Space Studies,
Clouds and the Earth’s Radiant Energy System (CERES), which
evolved from NASA’s Earth Radiation Budget Experiment,
Japan’s Advanced Microwave Scanning Radiometer for EOS(AMSR-E) and the Atmospheric Infrared Sounder (AIRS). Data
from the 2,378 infrared channels on the latter, together withthose from the microwave sounders, permit a highly accurate
temperature profile of the atmosphere from the surface to thehigh stratosphere to be derived.
CloudSat
Launched on a Delta rocket on April 28, 2006, CloudSat,
together with CALIPSO, was placed in a deployment orbit a few
kilometres below the planned operational orbit. After a 30-day
checkout period, CloudSat was nudged upwards to its operating
position trailing Aqua by about one minute.

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September 2006

Group for Earth Observation

GEO Quarterly No 11

CloudSat’s only
instrument is the Cloud
Profiling Radar (CPR)
developed jointly by
NASA’s Jet Propulsion
Laboratory and theCanadian Space Agency.
Both organisations haveextensive experience indesigning and building
satellite-borne radarsystems and are confident
that CPR will exceed its
22-month design life.
Artist's impression of CloudSat in orbit

CPR is a 94 GHz nadirCredit: NASAlooking radar; thisfrequency was considered to be the best compromise between
the larger antenna needed for a lower frequency and signal
attenuation through cloud at higher frequencies. Most groundbased weather radars operate at 3 GHz and are ideal for
locating heavy rain and hail but 94 GHz is well-suited forprofiling the much smaller drop sizes making up the clouds.

CALIPSO
CALIPSO, Cloud-Aerosol Lidar and Infrared Pathfinder
Satellite Observations, is stationed no more than 15 seconds(about 100 km) behind CloudSat so that they can both observe
the same clouds. Aerosols are small particles suspended in theatmosphere and arise both naturally, such as sea salt, desert
dust, forest fires and volcanic eruptions, and also as a result of
man’s activities such as the burning of fossil fuels and chemical
manufacturing. Not only are they a health hazard in highconcentrations but they are known to affect weather andclimate. Observations from spaceborne lidar, combined with
passive imagery, will lead to improved understanding of the role
aerosols and clouds play in regulating the Earth’s climate, inparticular, how the two interact. CALIPSO’s payload comprises
three co-aligned nadir-viewing instruments designed to operateautonomously and continuously.

Artist's impression of CALIPSO (foreground) with CloudSat
Credit: NASAtransmitter and an active boresight system to maintain coalignment between the transmitter and receiver• IIR (Imaging Infrared Radiometer), a nadir-viewing, threechannel imager with a swath width of 64 km and a pixel
size of 1 km. The CALIOP beam is aligned with the centreof the IIR image. The three channels in the thermal
infrared region are centred on 8.7, 10.5 and 12.0
micrometres to optimise joint CALIOP/IIR retrievals of
cirrus cloud emissivity and particle size
• WFC (Wide Field Camera), a modified version of acommercially available Ball Aerospace camera. It is a
fixed, nadir-viewing instrument with a single 50nm-wide
channel centred on 645nm which matches band 1 of the
MODIS instrument on Aqua.
PARASOL
PARASOL (Polarisation & Anisotropy of Reflectances for
Atmospheric Sciences coupled with Observations from a Lidar)
is the smallest component of the A-Train at just 120 kg and was
one of several secondary payloads launched with the French
military surveillance satellite Helios 2A in December 2004. It
was developed by CNES, France and lags CALIPSO by about
one minute.
The only instrument on PARASOL is POLDER (POLarisation
and Directionality of Earth’s Reflectances) whose measurements
will allow better characterisation of clouds and aerosols in
Earth’s atmosphere and, in particular, will distinguish between
natural and manmade aerosols. Three of POLDER’s nine
spectral bands are dedicated to observing ocean colour.
Aura
This word is derived from Latin and Greek words for breath or
breeze so is an appropriate name for a satellite carrying a suiteof instruments designed to gather data on five of the six ‘criteria
pollutants’ as identified by the US Environmental Protection
Agency. This powerful chemistry laboratory, launched in July
2004, flies about five minutes behind PARASOL and its four
instruments are studying the evolution of the vertical andhorizontal distribution of pollutants. They are the Tropospheric
Emission Spectrometer (TES), the Microwave Limb Sounder(MLS), the Ozone Monitoring Instrument (OMI) and the High
Resolution Dynamics Limb Sounder (HIRDLS).

Calipso's instruments
Credit: NASA

They are:• CALIOP (Cloud-Aerosol Lidar with Orthogonal
Polarisation), a two-wavelength polarisation-sensitive lidarthat provides high-resolution vertical profiles of aerosols
and clouds. The laser beams operate at 532 and 1064
nanometres in the green and near-infrared part of thespectrum respectively and the receive telescope has an
aperture of one metre. Ball Aerospace Corp developed the
instrument which also incorporates a redundant laser

OMI is far more sensitive than the Total Ozone Mapping
Spectrometer (TOMS) carried on seven earlier spacecraft andalso measures many other chemicals and trace gases. In
conjuction with Aura’s other instruments, it is now possible todistinguish between the ‘good’ ozone at high level which protects
us from dangerous ultraviolet radiation, and the ‘bad’ low-levelozone that creates a serious health hazard.
Within months of Aura’s launch there were two major volcanic
eruptions on inhabited Manam Island, Papua New Guinea, andon remote, uninhabited Anatahan in the Mariana Islands.

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19

GEO Quarterly No 11Group for Earth Observation

September 2006

Fred van den BoschThe activities concerning weather satellites consist of manydifferent, and often separate and independent programs. This
often results in a messy system where it’s difficult to find files
and automate processes. POVIM has been developed to provide a
structured and integrated environment. POVIM stands for
Product Oriented Video, Images and Maps (see page 23).
POVIM PM software integrates all the separate programs, andconsists of two parts:• the Product Manager and• the Presentation Manager
and offers the following possibilities:

This volcanic eruption on Anatahan Island was
subjected to detailed study by Aura's instruments.
Credit: MODIS Rapid Response Teamat NASA/GSFC

Aura’s instruments are ideally suited to monitor such events
within hours of their occurrence. Sulphur dioxide emissions areof particular concern; in the troposphere it is readily washed out
as acid rain but above the tropopause it is converted toparticulate sulphates which can persist for years and affect the
Earth’s radiation balance.
OCO
NASA’s Jet Propulsion Laboratory, in conjunction with Orbital
Sciences Corporation and Hamilton Sundstrand Sensor
Systems, are developing the Orbiting Carbon Observatory. To
be launched in 2008, OCO will be placed at the front of the
train, some 15 minutes ahead of Aqua. OCO’s instruments willmeasure carbon dioxide concentrations globally to an
unprecedented precision and resolution leading to a better
understanding of the sources, both natural and man-made, ofthe gas and where human-generated carbon dioxide is absorbed
from the atmosphere by natural processes.
Further Information
This has necessarily been only a brief account of a complex
project. Much more information can be found by entering ‘ATrain’ or the individual satellite names into one of the Internet
search engines.
Acknowledgement
The A-Train constellation image used in the heading for this article.
credit: NASA

Product Manager
Product Manager allows you to:• Create your own products and determine where they are to
be stored• Structure products to a maximum of 3 levels• Permits each level to be user-defined• Lets you combine similar products into specified groups, e.g.
Oceans, Hurricanes, Europe etc.
• You can create files with basic information• All the programs you use for weather satellites and weather
watching can be defined
Presentation Manager
The Product Manager allows you to:• Select up to 20 products from a list of products• Display all products as thumbnails• Synchronise scrolling in steps of 5, 15 and 60 minutes• Call your favourite photo viewer to examine the images on fullscreen• Use all the options of your photo viewer like zoom, scroll andprint• Choose a different date and time
• Display saved images or generate an image ‘on the fly’
• Display image details stored in the database• Display the latest received image• Display images (jpg, bmp) video (avi, mpeg) and maps(jpg,bmp) from other programs (e.g. Digital Atmosphere)• Start up a satellite or weather related program or visit a
specific Internet site.
• Directly start the photo viewer to see the content of all thefolders as thumbnails (depending on the options your viewer
provides)For whom is this program intended?
POVIM PM is useful for everybody using programs for generating
images from weather satellites or weather programs and wants
to maintain and view them in an easy and structured way.
A prototype was first showed on the GEO symposium 2006. You
can find my program on my website:
http://www.vandenbosch.speedlinq.nl/downloads.html

I will of course be interested in your comments, particularly any
bugs that you encounter.
I can be contacted by e-mail at:
Mount Etna trails an eruption plume in this Meteosat-8
HRV segment from 06:15 UT on July 27, 2006
Image © EUMETSAT 200620www.geo-web.org.uk

fred@vandenbosch.speedlinq.nl

September 2006

Group for Earth Observation

GEO Quarterly No 11David LeeDavid Lee is an employee of Moltek Consultants Limited, working at
EUMETSAT on the EARS project. David is in regularcommunication with David Taylor, who is currently developing thesoftware readers require to create images from the EAR-AVHRR
data (and shortly from MetOp). The article below is based on acommunication from David Lee outlining recent progress with theservices.
I am glad to see that you are enjoying the joined Svalbard / Lannion
AVHRR data! The step of getting Lannion and Svalbard to send out
AVHRR data is a very significant one for the EARS project and team.
We have been pushing to get the EARS stations upgraded for MetOp,
which has now mostly been done at Lannion (France), Longyearbyen(Svalbard) and Maspalomas (Canary Islands). This meant a lot ofwork with our station partners and our own new hardware
installations, and of course software upgrades, reconfigurations anddevelopment.
The Lannion and Svalbard stations, along with the central
EUMETSAT computer, are now working as an integrated system.
The stations are sending three-minute segments acquired from thesatellites to our remote computers at these sites. These computersthen create one-minute segments ready for dissemination and report(send a message) availability, completeness and quality to the centralcomputer ‘decision maker’. The decision maker will wait a short time
to receive messages about available segments at the remotecomputers and identify if there are any duplicate segments for thesame time slot (duplicates arise due to station coverage overlaps).
Finally, a decision is made as to which station has the best segment
and this decision is sent to the particular remote computer
instructing it to send the segment to the EUMETCast uplink server
and on to users. This means that overlaps between stations are
removed and end users should get a continuous set of ‘best quality’segments.
As I say, this is a significant step as there is a lot more involved ingetting the multi-station system communicating and working wellthan was the case in the simple single-station case we originallyoperated at Maspalomas. This also means that we will be able to add
new stations in more easily and provide users with long passes ofcontinuous high quality data. So Maspalomas should fit into thesystem fairly easily, though it is just going to take a bit of work to do
the upgrades.
The other target stations, Athens (Greece) and Kangerlussuaq(Greenland) could take a bit longer though—Greenland because of
the special communications to this site and Athens because ofongoing discussions with our station partner and other technicalissues.
I think the three stations (Lannion, Svalbard and Maspalomas)
should offer a good service for a while, though. We have been working
hard to get the data element up and running. Then I can work on
improving the monitoring and reporting of the system. We have some
limited monitoring on our side, but this needs to be finalised and thenput onto the ‘public’ side for reporting to users. For the moment weneed to keep taking all NOAA birds at Svalbard for test purposes, but
you should still get some nice long passes. Eventually we will send
the Svalbard and Lannion data out for the ATOVS service also. I’m
also glad to see that users understand that these systems are all newand that we will be working to improve the service in the near future.
Right:

A joined NOAA-17 channel-2 image comprising data captured
from both the Svalbard and Lannion acquisition stations.
Assembled by David Taylor using the AVHRR Manager,
then processed with HRPT Reader.

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GEO Quarterly No 11Group for Earth Observation

MSG2 Commissioning
MSG-2 was due to become operational on August 1, following
completion of commissioning operations, when it would be renamed
Meteosat-9. However, due to unexpected anomalies with two of its WV
6.2 µm channel detectors (discovered during the commissioning process
and still being investigated) it will be remain a back-up to Meteosat-8,
replacing Meteosat-7 which is being moved over the Indian Ocean totake over the IODC service from Meteosat-5. A trial of the direct
Meteosat-9 LRIT service commenced on August 2 and will continue,
possibly till the end of September. Meanwhile, Meteosat-8 will continue
as the primary operational satellite until further notice.

September 2006

NOAA-18 Frequency Change
The launch of MetOp inevitably resulted in the NOAA-18 frequency(changed to 137.10 MHz on January 4 this year) being switched back to
137.91 MHz on July 20. EUMETSAT requires the 137.10MHz frequency
for its MetOp LRPT service.

GEO Shop
Carol and Clive wish to thank all their customers for supporting the GEO
Shop. Already, they have exceeded last year’s entire turnover in just thefirst eight months of 2006. GEO Shop profits play an important role instabilising membership contributions and financing the group.

Dissemination of MSG-2 image data and meteorological products willcontinue on a trial basis via EUMETCast's Ku-band until the end of
September 2006, with meteorological products also being madeavailable on the Global Telecommunication System.

The Post Office launches its new ‘price in proportion’ scheme August 21
this year but, after looking at our prices, we have decided not to passon any additional costs incurred. Once again thank you all for yourcontinued support. We hope that you value our service.

Meteosat-7 Termination

R2FX NewsOn June 14, just before 09:00 UT, Meteosat-7 sent its final WEFAX
frame (a CTH) and so ended a service of WEFAX and PDUS imaging
from 0° which began in 1977 with Meteosat-1 (see GEO Quarterly 5
page 33). There was no 'on-air' celebration with a ‘goodbye’ ADMIN
frame—the transponder simply went dead.

Meteosat-7 heads for the Indian Ocean
On July 11, the operations team at EUMETSAT's Mission Control Centre
initiated Meteosat-7's three-month drift from 0° longitude to its new
location at 57.5° over the Indian Ocean where it will replace the longserving Meteosat-5. Both satellites will operate in parallel during
December, disseminating data via EUMETCast's Ku-band service. The
Indian Ocean Data Coverage (IODC) service provides critical data in aregion subject to severe, life-threatening natural events such as tropical
cyclones and tsunami, and Meteosat-7 will ensure continuation of thisservice until the end of 2008.
Meteosat-7 will also take over the Meteosat-5 Data Collection Platform(DCP) acquisition service from buoys located in the Indian Ocean. This
service makes data available to the international community for atsunami warning system for the region.
Once Meteosat-7 reaches its destination, Meteosat-6 will be drifted from
9.5°E to 63°E in early 2007. Meteosat-5 will then be jettisoned into agraveyard orbit during March 2007 prior to Meteosat-6’s arrival in
April/May.

How Meteosat-7 is Relocated
Geostationary satellites orbit the Earth from west to east, keeping pacewith the planet’s rotation and completing a full orbit once every siderealday. In order to relocate such a satellite, its path has to be changed bymoving it away from a geostationary orbit, when it will start drifting either
east or west depending on whether the orbit is lowered or raised
respectively. In order to move Meteosat-7 eastward its orbit has to belowered below geostationary level. Since the physical length of the orbit
is thus reduced, the satellite starts drifting to the east, a manoeuvre
effected by firing small thruster motors mounted on its side: these areangled appropriately to apply thrust in the desired direction. Once therequired longitude over the Indian Ocean has been attained thethrusters will be used to raise the satellite back into geostationary orbit.
In planning the drift itself, care has to be taken so that the east-drifting
orbit keeps Meteosat-7 at a safe distance from other objects in ageostationary orbit. The current catalogue of near-synchronous objects
was analysed in order to determine a safe altitude range during the drift
phase and a minimum distance of 39 kilometres below geostationary
altitude was determined to be appropriate. This corresponded to aminimum daily drift rate of 0.5 degree.
While Meteosat-7 is being drifted to its new position, it will continue
sending back images of the Earth, rectified every 10° to a different subsatellite point. Images captured during the drift should make for aninteresting animation as the satellite passing over regions previously notcovered by Meteosat-7, such as India, Siberia, China and parts ofSouth-East Asia. From its final position over the Indian Ocean,Meteosat-7 will have an excellent view of large parts of Europe, Africa,
the Middle East and Asia, as well as coverage of the Indian Ocean.

John Tellick has been testing an improved version of the German R2FXAPT receiver. John writes:‘I had been disappointed with the performance (at my location in SW
London) of the R2FX receiver, which was being badly affected by pager
interference. However, Holger Eckardt has provided an upgraded R2FX
which I have recently tested with the same set-up described in myarticle on page 4. I am very pleased to report that 137.91 MHz (and all
the other frequencies) are now free from pager breakthrough.
‘I haven’t been able to test 137.91 MHz with an actual APT signal ofcourse, but all my previous tests have shown that, if there is no pager
breakthrough on a frequency under zero-signal conditions, there has
been no problem with an APT signal present.’
The down side of all this is that the upgraded model would have tobe specially manufactured solely for the UK market, which would
inevitably make it more expensive. In the light of the NOAA-18
frequency change, any reader thinking of purchasing an upgraded
R2FX is advised to contact GEO Shop as soon as possible toexpress an interest. If there is sufficient interest (a minimum batch of
25 units would have to be produced), GEO will pursue the matter
further.

Svalbard Station Comes On-line
On July 18, 2006, the first data from the Svalbard (Norway) station
joined the stream of polar orbiting data now being broadcast over
EUMETSAT’s EUMETCast service (see our front cover illustration). Thisparticular data was received from the 14:20 UT pass of NOAA-17 andthe image includes the North Pole (upper left), Greenland (lower centre),and Svalbard (upper centre), where the reception station was located.
Data from the polar orbiting NOAA satellites complement those from theexisting geostationary satellites operated by EUMETSAT by providing
high-resolution polar coverage.
The data was sent from Svalbard to Darmstadt in Germany, where it
was processed and uplinked to the Hot Bird-6 satellite as part of the
EUMETCast pilot EARS AVHRR service. Well over a hundred users
were ready with David Taylor’s updated AVHRR Manager software,
which assembles the segments into a composite pass which can thenbe viewed using HRPT Reader.
For more information about software for processing EARS AVHRR data,
visit the ‘Satellite Tools’ section on David Taylor’s website (note the new
address) at:
Http://www.satsignal.eu

GEO-NETCastNOAA have begun a year long trial of Ku-band GEO-NETCast in theUSA. This is based on the Ku-band EUMETCast service we have inEurope (from Hot Bird-6), and the C-band service for Africa (via Atlantic
Bird-3) and the Americas (via NSS-806). The trial is being disseminated
via the AMC-3 satellite from a Ku-band transponder. An overview of thesystem can be found at
http://www.osd.noaa.gov/geo-netcast/... concluded on page 34

22

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September 2006

Group for Earth Observation

GEO Quarterly No 11

GEO PIC 1.0 for the RX2
Programmed with the
new channel frequencies
required for NOAA-18.
UK
Continental Europe
Rest of World

-

£7.00
£7.80
£8.40

GEO/Dartcom EPROM v 1.3
This new EPROM forthe Dartcom APT
receiver is available
exclusively from GEO.

Telestar 80 cm dish and Universal
0.6 dB LNB

R2FX APT Weather Satellite ReceiverThis diminutive German-built APT receiver is packed with features and is the ideal
receiver for the newcomer to the hobby. May be affected by pagers on the upper
NOAA frequency of 137.91 MHz.
UK member’s price
UK non-member’s price-(or similar model)
A quality German made aluminium dishand LNB with an AZ/EL mount to fit onto avertical pole. (Wall or patio mounts areavailable from local satellite TV dealers)
UK members price£49.00
UK non-members price£56.00UK
Continental Europe
Rest of World-£10.00£10.75£11.25

Martelec MSR40 EPROM
UK
Continental Europe
Rest of World-£10.00£10.75£11.25£135.00£149.00

Ordering and Shipping

R2FX Accessory Pack
This contains everything required to implement a complete APT receiving system
when used with the R2FX receiver. It comprises:• 137 MHz Turnstile Antenna• UK plug-in power supply• PC audio lead + PC Serial ‘computer control’ lead
• Aerial lead (20 m with fitted connector)• CD of PC shareware starter software• Instructions

few days for items to arrive in Europe

GEO can provide most of the items

and perhaps a few weeks for the Rest ofadvertised (with the exception of GEO

the World.

Quarterly back-issues and CDs) to both
members and non members. However,

Orders should be sent to:

the latter cannot benefit from thediscounted prices available to members.

GEO Shop,
We do not normally ship outside the UK as this receiver should be available
elsewhere more cheaply from the manufacturer. But contact the GEO Shop if you
wish a quote.
UK member’s price - £59.00
UK non-member’s price - £69.00

If you are not a GEO Member?

We will ship by post, so please allow a

44 Disraeli Road
Christchurch BH23 3NB
Dorset, England

Why not join GEO and takeadvantage of the discounted
prices we can offer members.

If you are paying by credit card, you can

Subscription Rates (12 months/4 issues

FAX us your order to:

of GEO Quarterly) are just £18 (UK),+44 (0) 1202 893 323£21 (EU) and £24 (rest of world).

GEO Members’ PRICE LIST
Members Prices
UK
EU RoW

Non Members
UK
EU RoW

135.00- 147.00
59.00
349.00259.00 279.00
37.50
7.00
7.80
8.40
10.00 10.75 11.25
10.00 10.75 11.25

149.00- 161.00
69.00
369.00279.00 299.00
42.50
7.00
7.80
8.40
10.00 10.75 11.25
10.00 10.75 11.25

53.50 55.00
94.50 113.50
49.00
11.00 12.50
21.50 24.50

59.50 61.00
119.50 123.50
56.00
17.50 19.00
24.50 27.50

APT Equipment
TechniSat SkyStar 2 PCI Card
This 'free-to-air' DVB satellite TV and data
receivercard
recommended
by
EUMETSAT must be installed inside yourcomputer. It comes with comprehensive
installation instructions and a CD-ROM ofdriver software (if you do not feel confident
about installing cards inside yourcomputer, we recommend the USB version
above)UK members price- £53.50
UK non-members price- £59.50

TechniSat SatFinder
Antenna Alignment Meter
This sensitive meter is a great help insetting up and aligning the dish for
maximum signal. The meter comes with full
instructions.
UK members price
UK non-member’s price- £21.50- £24.50

R2FX APT Receiver (no PSU)
R2FX Accessory Pack
Vierling Weatherman Complete Kit
Dartcom high quality QFH antenna
Turnstile APT antenna
GEO- PIC 1.0
GEO/Dartcom EPROM v 1.3
Martelec MSR40 EPROM

EUMETCast Equipment
TechniSat SkyStar 2 PCI Card
Technisat Skystar USB box
Telestar 80 cm dish with LNB
Telestar Ku band universal LNB
Technisat Satfinder alignment meter--

MiscellaneousTechniSat SkyStar 2 USB BoxThis external 'free-to-air' DVB satellite TV
and data receiver plugs into a USB port onyour computer and comes complete withpower supply, USB cable and a CD-ROMof driver software.
UK£94.50Continental Europe- £119.50

Telestar Universal Ku-band 0.6 dB
Universal LNB(or similar model)
Digital satellite TV Universal LNB for use
with the SkyStar receivers above or any
DVB satellite TV receiver.
UK members price£11.00Continental Europe£17.50GEO Quarterly Back Issues
3.50
4.20
5.10
(subject to availability)
GEO 2004 CD (PDF back issues)
8.00
8.80
9.30
GEO 2005 CD (PDF back issues)
8.00
8.80
9.30
GEO Membership (4 x GEO Quarterly) 18.00 21.00 24.00

n/a

n/a

n/a

n/a
n/a
n/a
n/a
n/a
n/a
18.00 21.00 24.00

All prices are in £ sterling and include postage and packaging

www.geo-web.org.uk

i

NOAA Satellite Predictions(Based on Latitude 52°N, Longitude 2°W, UT/GMT)NOAA 12137.50 MHz

NOAA 15137.50 MHz

Sep 01 05:07 06:46 14:54 16:32
Sep 02 04:42 06:22 16:08 17:49
Sep 03 05:57 07:37 15:43 17:24
Sep 04 05:32 07:12 15:19 16:58
Sep 05 05:08 06:48 14:55 16:34
Sep 06 04:43 06:23 16:09 17:50
Sep 07 05:58 07:39 15:45 17:25
Sep 08 05:34 07:14 15:20 17:00
Sep 09 05:09 06:49 14:56 16:35
Sep 10 04:44 06:24 16:10 17:51
Sep 11 05:59 07:40 15:46 17:26
Sep 12 05:35 07:15 15:22 17:01
Sep 13 05:10 06:50 14:58 16:36
Sep 14 04:46 06:25 16:11 17:53
Sep 15 04:21 06:01 15:47 17:27
Sep 16 05:36 07:16 15:23 17:02
Sep 17 05:11 06:51 14:59 16:37
Sep 18 04:47 06:27 16:13 17:54
Sep 19 04:23 06:02 15:48 17:29
Sep 20 05:37 07:17 15:24 17:03
Sep 21 05:13 06:53 15:00 16:39
Sep 22 04:48 06:28 16:14 17:55
Sep 23 04:24 06:03 15:50 17:30
Sep 24 05:39 07:19 15:25 17:05
Sep 25 05:14 06:54 15:01 16:40
Sep 26 04:49 06:29 16:15 17:57
Sep 27 04:25 06:04 15:51 17:31
Sep 28 05:40 07:20 15:27 17:06
Sep 29 05:15 06:55 15:02 16:41
Sep 30 04:51 06:30 16:16 17:58

05:59 07:39 15:46 17:26
05:35 07:16 15:23 17:02
05:12 06:52 16:38 18:19
04:48 06:28 16:15 17:55
06:04 07:44 15:51 17:31
05:40 07:20 15:28 17:07
05:17 06:57 16:43 18:24
04:53 06:33 16:19 18:00
06:09 07:49 15:56 17:36
05:45 07:25 15:33 17:12
05:21 07:01 16:48 18:29
04:58 06:38 16:24 18:05
06:14 07:54 16:01 17:41
05:50 07:30 15:38 17:16
05:26 07:06 15:14 16:53
05:03 06:42 16:29 18:10
06:19 07:59 16:06 17:45
05:55 07:35 15:42 17:21
05:31 07:11 15:19 16:57
05:07 06:47 16:34 18:15
06:23 08:04 16:10 17:50
06:00 07:40 15:47 17:26
05:36 07:16 15:24 17:02
05:12 06:52 16:39 18:20
04:49 06:28 16:15 17:55
06:04 07:45 15:52 17:31
05:41 07:21 15:29 17:07
05:17 06:57 16:43 18:25
04:53 06:33 16:20 18:00
06:09 07:50 15:56 17:36

10:33 12:13 20:20 21:59 02:29 04:10 12:22 14:03
10:10 11:50 19:58 21:36 02:19 04:00 12:12 13:52
09:47 11:27 21:13 22:54 02:09 03:50 12:01 13:42
11:04 12:44 20:51 22:31 01:58 03:39 11:51 13:32
10:41 12:21 20:28 22:08 01:48 03:29 11:41 13:21
10:18 11:58 20:06 21:44 01:38 03:19 11:31 13:11
09:55 11:35 21:21 23:03 01:28 03:08 11:21 13:01
09:32 11:12 20:59 22:39 01:17 02:58 12:50 14:33
10:49 12:29 20:36 22:16 01:07 02:48 12:40 14:22
10:26 12:06 20:14 21:52 00:57 02:38 12:30 14:11
10:03 11:43 21:29 23:11 02:27 04:09 12:20 14:01
09:40 11:20 21:07 22:47 02:17 03:58 12:10 13:50
10:57 12:37 20:44 22:24 02:07 03:48 11:59 13:40
10:34 12:14 20:21 22:00 01:56 03:37 11:49 13:30
10:11 11:51 19:59 21:37 01:46 03:27 11:39 13:19
09:48 11:28 21:14 22:55 01:36 03:17 11:29 13:09
11:05 12:45 20:52 22:32 01:26 03:07 11:19 12:59
10:42 12:22 20:29 22:08 01:15 02:56 12:48 14:31
10:19 11:59 20:07 21:45 01:05 02:46 12:38 14:20
09:56 11:36 21:22 23:04 00:55 02:36 12:28 14:09
09:33 11:13 21:00 22:40 02:25 04:07 12:18 13:59
10:49 12:30 20:37 22:17 02:15 03:56 12:08 13:48
10:27 12:07 20:14 21:53 02:05 03:46 11:58 13:38
10:04 11:44 19:52 21:30 01:54 03:36 11:47 13:28
09:41 11:20 21:07 22:48 01:44 03:25 11:37 13:17
10:57 12:38 20:45 22:25 01:34 03:15 11:28 13:07
10:34 12:15 20:22 22:01 01:24 03:05 11:18 12:57
10:11 11:52 20:00 21:38 01:14 02:54 12:46 14:29
09:49 11:28 21:15 22:56 01:03 02:44 12:36 14:18
11:05 12:46 20:53 22:33 02:34 04:15 12:26 14:07

Nov 01 05:00 06:40 14:48 16:26
Nov 02 04:36 06:15 16:02 17:42
Nov 03 05:51 07:31 15:37 17:17
Nov 04 05:26 07:06 15:13 16:52
Nov 05 05:01 06:41 14:49 16:27
Nov 06 04:37 06:17 16:03 17:44
Nov 07 05:52 07:32 15:38 17:18
Nov 08 05:27 07:07 15:14 16:53
Nov 09 05:03 06:42 14:50 16:29
Nov 10 04:38 06:18 16:04 17:45
Nov 11 05:53 07:33 15:40 17:20
Nov 12 05:28 07:08 15:16 16:55
Nov 13 05:04 06:44 14:52 16:30
Nov 14 04:39 06:19 16:05 17:46
Nov 15 05:54 07:34 15:41 17:21
Nov 16 05:30 07:10 15:17 16:56
Nov 17 05:05 06:45 14:53 16:31
Nov 18 04:40 06:20 16:06 17:47
Nov 19 05:55 07:36 15:42 17:22
Nov 20 05:31 07:11 15:18 16:57
Nov 21 05:06 06:46 14:54 16:32
Nov 22 04:42 06:21 16:08 17:48
Nov 23 05:57 07:37 15:43 17:23
Nov 24 05:32 07:12 15:19 16:58
Nov 25 05:07 06:47 14:55 16:33
Nov 26 04:43 06:23 16:09 17:50
Nov 27 05:58 07:38 15:44 17:24
Nov 28 05:33 07:13 15:20 16:59
Nov 29 05:09 06:48 14:56 16:35
Nov 30 04:44 06:24 16:10 17:51

05:08 06:48 16:35 18:16 10:29 12:09 20:17 21:55
04:45 06:24 16:11 17:51 10:06 11:46 19:54 21:32
06:00 07:41 15:48 17:27 09:43 11:23 21:09 22:50
05:37 07:17 15:25 17:03 10:59 12:40 20:47 22:27
05:13 06:53 16:39 18:21 10:36 12:17 20:24 22:03
04:49 06:29 16:16 17:56 10:13 11:54 20:02 21:40
06:05 07:46 15:52 17:32 09:51 11:30 21:17 22:58
05:42 07:22 15:29 17:08 11:07 12:48 20:55 22:35
05:18 06:58 15:06 16:44 10:44 12:25 20:32 22:11
04:54 06:34 16:21 18:01 10:21 12:01 20:09 21:48
06:10 07:50 15:57 17:37 09:58 11:38 21:25 23:07
05:46 07:26 15:34 17:13 09:36 11:15 21:02 22:43
05:23 07:03 15:11 16:49 10:52 12:32 20:40 22:19
04:59 06:39 16:25 18:06 10:29 12:09 20:17 21:56
06:15 07:55 16:02 17:42 10:06 11:46 19:55 21:33
05:51 07:31 15:39 17:18 09:43 11:23 21:10 22:51
05:27 07:07 15:15 16:54 11:00 12:40 20:47 22:27
05:04 06:44 16:30 18:11 10:37 12:17 20:25 22:04
06:20 08:00 16:07 17:47 10:14 11:54 20:02 21:41
05:56 07:36 15:43 17:23 09:51 11:31 21:18 22:59
05:32 07:12 15:20 16:59 11:08 12:48 20:55 22:35
05:09 06:48 16:35 18:16 10:45 12:25 20:32 22:12
04:45 06:25 16:11 17:52 10:22 12:02 20:10 21:49
06:01 07:41 15:48 17:27 09:59 11:39 21:26 23:07
05:37 07:17 15:25 17:03 09:36 11:16 21:03 22:43
05:13 06:53 16:40 18:21 10:53 12:33 20:40 22:20
04:50 06:29 16:16 17:57 10:30 12:10 20:18 21:56
06:06 07:46 15:53 17:32 10:07 11:47 19:55 21:33
05:42 07:22 15:30 17:08 09:44 11:24 21:10 22:51
05:18 06:58 15:06 16:45 11:00 12:41 20:48 22:28

02:07 03:48 12:00 13:41
01:57 03:38 11:50 13:30
01:47 03:28 11:40 13:20
01:37 03:17 11:30 13:09
01:26 03:07 11:20 12:59
01:16 02:57 12:49 14:31
01:06 02:47 12:39 14:21
00:56 02:36 12:28 14:10
02:26 04:07 12:18 13:59
02:16 03:57 12:08 13:49
02:05 03:47 11:58 13:39
01:55 03:36 11:48 13:28
01:45 03:26 11:38 13:18
01:35 03:16 11:28 13:07
01:24 03:05 11:18 12:57
01:14 02:55 12:47 14:29
01:04 02:45 12:37 14:19
00:54 02:34 12:27 14:08
02:24 04:05 12:16 13:58
02:14 03:55 12:06 13:47
02:03 03:45 11:56 13:37
01:53 03:34 11:46 13:26
01:43 03:24 11:36 13:16
01:33 03:14 11:26 13:06
01:22 03:03 11:16 12:55
01:12 02:53 12:45 14:27
01:02 02:43 12:35 14:17
02:32 04:14 12:25 14:06
02:22 04:03 12:14 13:56
02:12 03:53 12:04 13:45

Oct 01 04:26 06:06 15:52 17:32
Oct 02 05:41 07:21 15:28 17:07
Oct 03 05:16 06:56 15:04 16:42
Oct 04 04:52 06:32 16:18 17:59
Oct 05 04:27 06:07 15:53 17:34
Oct 06 05:42 07:22 15:29 17:08
Oct 07 05:18 06:58 15:05 16:44
Oct 08 04:53 06:33 16:19 18:00
Oct 09 04:29 06:08 15:54 17:35
Oct 10 05:43 07:24 15:30 17:10
Oct 11 05:19 06:59 15:06 16:45
Oct 12 04:54 06:34 16:20 18:02
Oct 13 04:30 06:09 15:56 17:36
Oct 14 05:45 07:25 15:31 17:11
Oct 15 05:20 07:00 15:07 16:46
Oct 16 04:55 06:35 14:43 16:21
Oct 17 04:31 06:11 15:57 17:37
Oct 18 05:46 07:26 15:33 17:12
Oct 19 05:21 07:01 15:08 16:47
Oct 20 04:57 06:36 14:45 16:23
Oct 21 04:32 06:12 15:58 17:39
Oct 22 05:47 07:27 15:34 17:13
Oct 23 05:22 07:02 15:10 16:48
Oct 24 04:58 06:38 14:46 16:24
Oct 25 04:33 06:13 15:59 17:40
Oct 26 05:48 07:28 15:35 17:15
Oct 27 05:24 07:04 15:11 16:50
Oct 28 04:59 06:39 14:47 16:25
Oct 29 04:35 06:14 16:00 17:41
Oct 30 05:49 07:30 15:36 17:16
Oct 31 05:25 07:05 15:12 16:51

05:46 07:26 15:33 17:12
05:22 07:02 15:10 16:48
04:58 06:38 16:25 18:05
06:14 07:54 16:01 17:41
05:50 07:31 15:38 17:17
05:27 07:07 15:15 16:53
05:03 06:43 16:29 18:10
06:19 07:59 16:06 17:46
05:55 07:35 15:43 17:22
05:31 07:12 15:20 16:58
05:08 06:48 16:34 18:15
06:24 08:04 16:11 17:51
06:00 07:40 15:47 17:27
05:36 07:16 15:24 17:03
05:13 06:52 16:39 18:20
04:49 06:29 16:15 17:56
06:05 07:45 15:52 17:32
05:41 07:21 15:29 17:08
05:17 06:57 16:44 18:25
04:54 06:34 16:20 18:01
06:10 07:50 15:57 17:37
05:46 07:26 15:34 17:12
05:22 07:02 15:11 16:49
04:59 06:38 16:25 18:06
06:15 07:55 16:02 17:41
05:51 07:31 15:38 17:17
05:27 07:07 15:15 16:53
05:03 06:43 16:30 18:11
06:19 08:00 16:06 17:46
05:56 07:36 15:43 17:22
05:32 07:12 15:20 16:58

10:42 12:23 20:30 22:09 02:23 04:05 12:16 13:57
10:19 11:59 20:08 21:46 02:13 03:54 12:06 13:46
09:56 11:36 21:23 23:05 02:03 03:44 11:56 13:36
09:34 11:13 21:00 22:41 01:53 03:34 11:46 13:26
10:50 12:31 20:38 22:17 01:42 03:23 11:36 13:15
10:27 12:07 20:15 21:54 01:32 03:13 11:26 13:05
10:04 11:44 19:53 21:31 01:22 03:03 11:16 12:55
09:42 11:21 21:08 22:49 01:12 02:52 12:44 14:27
10:58 12:39 20:45 22:25 01:01 02:42 12:34 14:16
10:35 12:15 20:23 22:02 02:32 04:13 12:24 14:05
10:12 11:52 20:01 21:39 02:21 04:03 12:14 13:55
09:49 11:29 21:16 22:57 02:11 03:52 12:04 13:44
11:06 12:47 20:53 22:33 02:01 03:42 11:54 13:34
10:43 12:23 20:31 22:10 01:51 03:32 11:44 13:24
10:20 12:00 20:08 21:47 01:40 03:21 11:34 13:13
09:57 11:37 21:24 23:05 01:30 03:11 11:24 13:03
09:34 11:14 21:01 22:42 01:20 03:01 11:14 12:53
10:51 12:31 20:38 22:18 01:10 02:50 12:42 14:25
10:28 12:08 20:16 21:55 01:00 02:40 12:32 14:14
10:05 11:45 19:54 21:32 02:30 04:11 12:22 14:03
09:42 11:22 21:09 22:50 02:20 04:01 12:12 13:53
10:59 12:39 20:46 22:26 02:09 03:50 12:02 13:42
10:36 12:16 20:24 22:03 01:59 03:40 11:52 13:32
10:13 11:53 20:01 21:40 01:49 03:30 11:42 13:22
09:50 11:30 21:17 22:58 01:38 03:19 11:32 13:11
11:07 12:47 20:54 22:34 01:28 03:09 11:22 13:01
10:44 12:24 20:31 22:11 01:18 02:59 12:51 14:33
10:21 12:01 20:09 21:48 01:08 02:49 12:41 14:23
09:58 11:38 21:25 23:06 00:58 02:38 12:30 14:12
09:35 11:15 21:02 22:42 02:28 04:09 12:20 14:01
10:52 12:32 20:39 22:19 02:18 03:59 12:10 13:51

Dec 01 05:59 07:39 15:46 17:26
Dec 02 05:34 07:14 15:21 17:01
Dec 03 05:10 06:50 14:57 16:36
Dec 04 04:45 06:25 16:11 17:52
Dec 05 06:00 07:40 15:47 17:27
Dec 06 05:36 07:16 15:23 17:02
Dec 07 05:11 06:51 14:59 16:37
Dec 08 04:46 06:26 16:12 17:53
Dec 09 06:01 07:42 15:48 17:28
Dec 10 05:37 07:17 15:24 17:03
Dec 11 05:12 06:52 15:00 16:38
Dec 12 04:48 06:27 16:13 17:55
Dec 13 06:03 07:43 15:49 17:29
Dec 14 05:38 07:18 15:25 17:04
Dec 15 05:13 06:53 15:01 16:39
Dec 16 04:49 06:29 16:15 17:56
Dec 17 06:04 07:44 15:50 17:30
Dec 18 05:39 07:19 15:26 17:05
Dec 19 05:15 06:54 15:02 16:40
Dec 20 04:50 06:30 16:16 17:57
Dec 21 06:05 07:45 15:51 17:32
Dec 22 05:40 07:20 15:27 17:06
Dec 23 05:16 06:56 15:03 16:42
Dec 24 04:51 06:31 16:17 17:58
Dec 25 04:27 06:06 15:53 17:33
Dec 26 05:42 07:22 15:28 17:08
Dec 27 05:17 06:57 15:04 16:43
Dec 28 04:52 06:32 16:18 17:59
Dec 29 04:28 06:07 15:54 17:34
Dec 30 05:43 07:23 15:29 17:09
Dec 31 05:18 06:58 15:05 16:44

04:55 06:34 16:21 18:02 10:37 12:18 20:25 22:04
06:11 07:51 15:57 17:37 10:14 11:55 20:03 21:41
05:47 07:27 15:34 17:13 09:52 11:31 21:18 22:59
05:23 07:03 15:11 16:49 11:08 12:49 20:55 22:36
04:59 06:39 16:26 18:07 10:45 12:26 20:33 22:12
06:15 07:56 16:02 17:42 10:22 12:02 20:10 21:49
05:52 07:32 15:39 17:18 09:59 11:39 21:26 23:08
05:28 07:08 15:16 16:54 09:36 11:16 21:03 22:44
05:04 06:44 16:30 18:12 10:53 12:33 20:40 22:20
06:20 08:01 16:07 17:47 10:30 12:10 20:18 21:57
05:56 07:37 15:44 17:23 10:07 11:47 19:56 21:34
05:33 07:13 15:20 16:59 09:44 11:24 21:11 22:52
05:09 06:49 16:35 18:17 11:01 12:41 20:48 22:28
04:45 06:25 16:12 17:52 10:38 12:18 20:26 22:05
06:01 07:41 15:48 17:28 10:15 11:55 20:03 21:42
05:37 07:18 15:25 17:04 09:52 11:32 21:19 23:00
05:14 06:54 16:40 18:22 11:09 12:49 20:56 22:36
04:50 06:30 16:16 17:57 10:46 12:26 20:33 22:13
06:06 07:46 15:53 17:33 10:23 12:03 20:11 21:49
05:42 07:22 15:30 17:09 10:00 11:40 21:26 23:08
05:19 06:59 15:07 16:45 09:37 11:17 21:03 22:44
04:55 06:35 16:21 18:02 10:53 12:34 20:41 22:21
06:11 07:51 15:58 17:38 10:30 12:11 20:18 21:57
05:47 07:27 15:35 17:14 10:08 11:48 19:56 21:34
05:23 07:03 15:11 16:50 09:45 11:24 21:11 22:52
05:00 06:40 16:26 18:07 11:01 12:42 20:48 22:29
06:16 07:56 16:03 17:43 10:38 12:18 20:26 22:05
05:52 07:32 15:39 17:18 10:15 11:55 20:03 21:42
05:28 07:08 15:16 16:55 09:52 11:32 21:19 23:00
05:05 06:44 16:31 18:12 09:30 11:09 20:56 22:36
04:41 06:21 16:07 17:48 10:46 12:26 20:33 22:13

02:01 03:43 11:54 13:35
01:51 03:32 11:44 13:24
01:41 03:22 11:34 13:14
01:31 03:12 11:24 13:04
01:20 03:01 11:14 12:53
01:10 02:51 12:43 14:25
01:00 02:41 12:33 14:15
02:30 04:12 12:23 14:04
02:20 04:01 12:13 13:54
02:10 03:51 12:02 13:43
01:59 03:41 11:52 13:33
01:49 03:30 11:42 13:22
01:39 03:20 11:32 13:12
01:29 03:10 11:22 13:02
01:18 02:59 11:12 12:51
01:08 02:49 12:41 14:23
00:58 02:39 12:31 14:13
02:28 04:10 12:21 14:02
02:18 03:59 12:11 13:52
02:08 03:49 12:00 13:41
01:57 03:39 11:50 13:31
01:47 03:28 11:40 13:20
01:37 03:18 11:30 13:10
01:27 03:08 11:20 13:00
01:16 02:57 12:49 14:32
01:06 02:47 12:39 14:21
00:56 02:37 12:29 14:11
02:26 04:08 12:19 14:00
02:16 03:57 12:09 13:49
02:06 03:47 11:58 13:39
01:55 03:36 11:48 13:29

ii

NOAA 17137.62 MHz

NOAA 18
137.91 MHzNOAA 12137.50 MHz

NOAA 15137.50 MHz

NOAA 17137.62 MHz

You can download a PDF version of these predictions from: http://www.geo-web.org.uk/predictions.pdf

NOAA 18
137.91 MHz

September 2006

Group for Earth Observation

GEO Helplines
Douglas Deans, Dunblane, Perthshire, SCOTLAND
All aspects of weather satellites from APT, HRPT to Meteosat-8 DVB/EUMETCast systems.
• telephone:(01786) 82 28 28• e-mail: douglas@dsdeans.freeserve.co.uk
John Tellick, Surbiton, Surrey, ENGLAND
Meteosat-8 advice - registering for the various MSG services, hardware and software installationand troubleshooting. John will also field general queries about any aspect of receiving weather
satellite transmissions.
• telephone: (0208) 390 3315
• e-mail: info@geo-web.org.uk
Keith Holland, London, ENGLAND
Specifically, help for APT users (137 MHz band).
• e-mail: geo@koholland.plus.com
David Strickland, Truro, Cornwall, ENGLANDDavid has set up his own wireless network system of three computers. He has interests inelectronic design and prototyping, general computing, microchip processors with various facilities
and of course MSG satellite imaging. He will be happy to discuss any of the above topics, and tohelp anyone local, including viewing his setup.
• e-mail: David@Strickland.uk.com
Geoff Morris GW3ATZ, Shotton, Flintshire, NE WALES
Geoff has lots of experience with aerial, co-ax,connectors, mounting hardware etc. and has alsodone a lot of work with the orbiting satellites. Geoff has been a EUMETCast Meteosat-8 user forsome time and is familiar with David Taylor’s MSG software; he should be able to share his
experiences with newcomers to this branch of the hobby.
• Tel: (01244) 818252• e-mail: gw3atz@btopenworld.com
Guy Martin G8NFU, Biggin Hill NW Kent, ENGLAND
Guy is prepared to advise anyone who wishes to receive MSG under Windows 2000.
• agm@tonbridge-school.org
Hector Cintron, San Juan, Puerto Rico, USA
Hector is prepared to field enquiries on HRPT, APT, EMWIN and NOAAPORT• Phone: 787-774-8657• e-mail: n1tkk@hwic.net
E-mail contact can of course be made at any time, but we would ask you to
restrict telephone contact to the period 7.00-9.00 pm in the evenings.

Useful Internet
Discussion Groups
There are a number of Internet-based discussion groups available to weather satellite enthusiasts.
You can join any of these by sending an e-mail to the appropriate address, with a request to
subscribe. Indeed, a blank e-mail containing the word ‘subscribe’ in its Subject line is all that isrequired. Some of the more useful groups and their contact addresses are listed below.
GEO-Subscribers
This is a group where GEO members can exchange information relating to either GEO itself orEarth observation satellites and related matters.
e-mail:GEO-Subscribers-subscribe@yahoogroups.com

Satsignal
An end-user self help group for users of David Taylor's Satellite Software Tools including the orbit
predictor WXtrack; the file decoders GeoSatSignal and SatSignal; the HRPT Reader and image
creator program; the image remapper GroundMap; and software for the EUMETCast service—theMSG Data Manager, the AVHRR Manager and the ATOVS Reader.

GEO Quarterly No 11

Copy Deadline
for GEO Quarterly No 11

Saturday, October 28
The Editor is always on the lookout for articles
and images for inclusion in GEO Quarterly.
These can relate to any aspect of Earth
Imaging, especially:• Technical articles concerning relevant
hardware / software• Construction projects• Weather satellite images• Reports on weather phenomena• Descriptions of readers’ satellite imaging
stations• Activities from overseas readers• Letters to the Editor• Problems and Queries for our experts toanswerContributions should of course be original and,
where possible, should be submitted to theeditor in electronic format (floppy disc, e-mailattachment, CD). But of course we will also
accept handwritten or typed copy should theneed arise.
Please note, however, that major articles
which contain large numbers of satellite
images, photographs or other illustrations
should be submitted as early as possible sothat they can be prepared and made up into
pages in time for publication.

Images and Diagrams
Images can be accepted in any of the major
bitmap formats, e.g. JPG, BMP, GIF, TIFF etc.
Images in both monochrome and colour are
welcomed for inclusion. Line drawings anddiagrams are preferred in Windows metafile
and postscript formats. We can also scanoriginal photographs, negatives and slides.
Gridding, Overlays and Captions
Please note that readers’ satellite images
should be provided without added gridlines,
country outlines or captions unless these areconsidered essential to illustrate an article.
If your article submission contains embedded
images and diagrams, please note that it isessential that you also submit the individual
images in one of the formats described above:these are essential for page make-up
purposes.
Submission of Copy
All materials for publication should be sent to
the Editor, Les Hamilton, 8 Deeside Place,
Aberdeen, AB15 7PW, Scotland.

e-mail: SatSignal-subscribe@yahoogroups.com

MSG-1
A forum dedicated to Meteosat Second Generation (MSG), where members can share information
about the EUMETCast reception hardware and software for the Meteosat geostationary satellites.
e-mail: MSG-1-subscribe@yahoogroups.com

Weather Satellite Reports
A group providing reports, updates and news on operational aspects of weather satellites.

Materials may also be sent as attachments tothe following e-mail address:
editor@geo-web.org.uk

Larger attachments (1 Mb to 10 Mb) are best
sent to:editor.geo@googlemail.com

e-mail: weather-satellite-reports-subscribe@yahoogroups.com

WXtoImg
Users of the WXtoImg software package for capturing and imaging NOAA APT can air theirproblems, discuss its features and ask questions about it.
e-mail: wxtoimg-subscribe@yahoogroups.com

www.geo-web.org.uk

And finally . . . if you do have material ready forthe next GEO Quarterly, please submit it assoon as it is ready—do not wait till the deadline
before sending it in. This simply creates an
editorial log-jam.

iii

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iv

www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

If you need to check whether all the desired programs are actuallyrunning on your computer following bootup or logon, I recommend
using the handy utility called Autoruns [3]. The Windows logon
screen of Autoruns is shown in figure 1.

Fred van den BoschThe sheer volume of data now available via EUMETCast, where
the original MSG 15-minute data has been augmented by SAF
products, EARS-ATOVS and most recently EARS-AVHRR data,means that it is essential to automate your station. You cannot sit
in front of your PC 24 hours per day monitoring its output,
creating products from the data and filing everything away in ameaningful way. This article is a continuation from POVIM [1]and describes how a system can be arranged so that as many
processes as possible are automated in the simplest possible way.
This is where true automation begins.
There are several ways to realise this ideal but, however it isachieved, I must emphasise that a consistent and unambiguousplan of campaign is necessary to keep the process manageable.
Automation can take place in several ways and on several levels:
1 During the system start-up
2 By batch operation with .BAT files
3 Through batch programs via a Task Manager
4 Other possibilities
Below, I describe a number of different solutions for each of theabove. I do assume a certain basic knowledge of both computerand software management on the part of the user: for example, I
may state that a shortcut must be made—but I won’t explain how
you do this. Without this basic knowledge it is nearly impossible
to achieve everything. Moreover, bearing in mind the KISS
Principle [2], no exotic scripts are used.
System Start-up
This is the first level of attack. It is very easy to make a numberof programs start automatically as part of your PC’s boot-up
sequence. All that is needed is the creation of a shortcut for eachsuch program in the start-up folder. Every time the system isstarted up, these programs will automatically start up too. This isparticularly important for anyone who uses TechniSat reception
software with MSG Data Manager (Meteosat) and the AVHRRManager (NOAA and MetOp HRPT). If the system resets itself
during the night (I believe this has happened at me a couple times
as a result of an automatic Windows update) then you will lose
very little data.
In the case of MSG Data Manager it is a good idea, after making
the shortcut, to append the parameter ‘-START’ to the ‘Target’
path under ‘Properties’. This means that after Data Manager
restarts it immediately starts running again, so that you do nothave to ‘catch up with data’ several hours later as you would
following a manual restart.

Operations Using Batch (.BAT) Files
Batch files contain a number of commands which are all executed
one after the other when the file is run in either MS-DOS orWindows. An example could be a batch file which allowed anumber of different images to be made with GeoSatSignal. In
general, no special programming ability is required for making
batch files. A batch file is a text file, with filename extension ‘.bat’,which can be created using Notepad. It’s a good idea to make ashort-cut to each batch file.
A Typical Batch File Example
Here’s a simple example of what is possible with a batch file. I
myself use, among others, the programs WXSIM andWXSIMATE [4]. They are respectively, a program that makes alocal weather forecast and a utility which downloads data fromthe Internet. At the same time, during the download, one’s own
data can be added.
To save time I have placed all this in a shortcut on the Desktop,
which calls the following batch file.
copy \\Satellieten\weatherdisplay\logfiles\*.* d:\logfiles\
wxsimateREADY.lnk
c:\windows\notepad.exe D:\Program Files\wxsim\Data\a.dat
wxsimate.lnk
wxsim.lnk
After clicking the shortcut for this batch file, the following
happens:
1 Logfiles are copied from my satellite weather station PC to mylarge system
2 The shortcut ‘wxsimateREADY’ with content (“C:\Program
Files\Internet Explorer\iexplore.exe”“http://www.arl.noaa.gov/ready/cmet.html”) is started. This
opens Internet Explorer and visits a site where some data
must be gathered manually.
3 Notepad opens up and the file ‘a.dat’ is opened and the datacollected in the previous step are added to it.
4 As soon as Notepad is closed, a shortcut is called to start up
WXSIMATE. This program downloads data from the Internet
and adds the contents of the file a.dat (from step 3) to it.
5 A final shortcut is called to run WXSIM which starts thepredicting stage.
This is just an example—one of my own batch files—to illustrate
the technique. Everyone can create their own batch files to suit
their needs. It’s simply a question of ‘try it and see what happens’.
Batch Programming by Means of a Task Manager
In particular, David Taylor’s programs offer the possibility ofbatch operations. This means that the data are taken up once
only, in the form of a program line and a parameter line, both ofwhich can be incorporated in a task manager. Here’s an example
to show how to do it.

The Program Line
D:\Program files\David Taylor\GeoSatSignal\GeoSatSignal.exe

This opens the GeoSatSignal program.

The Parameter Line
D:\products\data\HRIT\*ch12nw.jpg -j19 remap:D:\products\MSG\J19_HRV_Europa\%YY%MM%DD%HH%NN.jpg -minFigure 1 - Autoruns in action

This does three things:• The most recent ch12nw image is opened.
• This image is remapped according to the data in
GSS-job 19.
• The result is written away to the folder ‘J19_HRV_Europa’.
www.geo-web.org.uk

23

GEO Quarterly No 11Group for Earth Observation

The variables named %YY etc. ensure that the filename underwhich the final image is saved has the form ‘year-month-dayhour-minute’.
Task Managers
A task manager is a program which remains active in the
background and which ensures that all your batch files arestarted up automatically at the desired times. Such a task
manager will contain details of those programs or batch files you
want to run, the times when they must be activated, and whether
this takes place daily, weekly or whatever (based on the system
clock). I’ll briefly discuss some of the different task managers thatyou can use.

September 2006

To learn more about the fixed data, I refer you to the help-file,where the individual parameters are treated in depth.

One or more blocks with, for every block• The address of the site and folder where the file must be
saved• The name of the location on the site and the name underwhich it must be stored.
Here is an example of the second block-data part
SITE=http://oiswww.eumetsat.int/~idds/data/grib#DIR=D:\PRODUCTS\DATA\MPEF\%y\%m\%dMPE_%y%m%d_0030_M5_63.grb#FILE=%y%m%d0030-mpe-5.grb,t=0030

The Standard Windows Task Manager
This is accessed from the Windows Control Panel by doubleclicking ‘Scheduled tasks’. All tasks planned will already be foundin the list. You can add a new task to the list by clicking <New
Scheduled task>.

MPE_%y%m%d_0100_M5_63.grb#FILE=%y%m%d0100-mpe-5.grb,t=0100

Other Task Managers
If you use Google to search the Internet you can find an enormous
number of task managers. Frequently these offer extra options or
greater ease of use than Windows Task Manager and most ofthem are freeware. Because choice of this type program isfrequently based on individual preference, I’m not going to statea personal favourite. Everyone can decide on his own preferredversion. I want nevertheless to name two you might wish to try.

On the first line, ‘SITE’ is followed by the address where the files
can be found. Following the # is the folder where the files must be
stored. Here also variables such as %y, %m. etc. may be used.
These are converted during the process to the real value.
Although it is not obligatory that the ‘DIR’ command be on thesame line as ‘SITE’, this is very strongly recommended by theauthor of the program (Francis Breame).

VisualCron [5] offers vast possibilities. Some of the most useful

The exact name of the program, as listed on the site, must appear
first on the line. If the file is to be written under a different name,this can be done by means of the subsequent ‘FILE’ command. If
this is omitted, the original name is used. Next follows the time
(t=xxxx) at which the download must start. This overwrites thedefault time from the first block.

include• adding scheduled jobs using a visual/graphical mode
• edit jobs easily with a right mouse-click• view active jobs in a list with name, description and current
status• customised popup, e-mail, play sound, popup message,
execute sql• run missed eventsand perhaps the most important:• one job can have many tasks that can be run in order.

Macro Maker [6]. The particular strength of this program is thatit allows you to record a sequence of mouse-clicks and play themback later. I have, however, found it very difficult to build more
complex macros. Among other things you must ensure thatpauses are regularly built in because otherwise the processing of
the macro commands proceeds faster than the screen refreshes.
If you would like to learn what a professional (commercial) task
manager can achieve, take a look at Automate [7]. On theirwebsite you will find a training video and data sheets which give
an impression of how this kind of program works. This
information may help you to decide which task manager is bestfor you.
Other Possibilities
There are obviously more ways to deal with automatic tasks.
Here are a couple more options.
GetCharts [8] is a Perl script which allows you to automaticallydownload files from the Internet by either FTP or HTTP atplanned times according to a configuration file. As the program
has a huge help file, I will only discuss the main ideas.
The details are provided by means of a script, which consists of
two parts:

Fixed data which apply to the complete script
Here is a selection:• the number of times that a download should be attempted• its own e-mail address• whether a file that has already been transferred should beoverwritten.

24

MPE_%y%m%d_0130_M5_63.grb#FILE=%y%m%d0130-mpe-5.grb,t=0130

etc.

The Address

Files

Download Manager
A download manager can also be useful for large files. Such a
program allows you to download a large file faster by using
several simultaneous Internet connections. GetCharts has beentested with the download manager program GetRight [9]. In
GetRight you can decide yourself when to download files,
including variables for year, month etc, and for some files thisworks well. If you require to download large quantities of data
frequently (every half hour, for instance), then GetCharts is amuch better choice.
Optimisation
From the beginning it is necessary to optimise the processing. Do
not wait until everything has been completed because by thatstage it becomes very difficult to alter and improve things.
Planning
It is important to plan your batch files carefully. You do not wantto overload your system by running them all at the same time. I
have created a spreadsheet for this purpose where the minutes
increment line by line and the hours are listed across thecolumns. The name of each batch file is listed on the line
representing the minute at which it must be started. Where theminute lines intersect the hour columns, a cross indicates those
hours during which the batch file should be activated. If a batch
file runs every 15 minutes, its name would therefore appear on
four different lines. Figure 2 (next page) shows the first few linesof the spreadsheet.
FreeRAM XP pro
The most important aim of this freeware program [10] is freeing
memory, which can be done automatically as well as manually.
The more free memory you have, the faster your system is.
Moreover, this program can give an overview as to how muchmemory space each program requires.
This can be very handy at optimising the system. In this way I
have found that Digital Atmosphere uses up approximately

www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

20 MB when it starts up but after running for a full day thisincreases to around 400 MB! It is clear that this can lead toproblems.
A solution is to make a script with the single command‘TIMERON’ and store this under a name like start.dsf. Next, ashortcut is made to Digital Atmosphere with start.dsf as its
parameter. At a particular time we program the task manager toclose DAWS and then start it up again with start.dsf.
TrimTreeTrim Tree is an unsupported program from David Taylor which
can be downloaded from the ‘Disc Utilities’ section of his website
at:www.satsignal.eu

Figure 2 - Spreadsheet

It can remove files that are older than a given number of days. It
is very handy for deleting all the files you automatically makeeach day by incorporating one or more commands in a batch file.
Here is an example to remove SAF-files older than 3 days.

‘Settings’, use the ‘Browse’ button to navigate to a folder where
your most recent images have been stored.

TrimTree 3 C:\MSG - 1 \ images \ SAF \ * - LMLDLI_ *.* * - LMLSSI_ *.** - LMLSST_ *.* * - MAPDLI_ *. * * - MAPSSI_ *. * * - NARSST *. *All this is on one line. These batch files can be incorporated into
the task manager so that old files are automatically and regularly
deleted. If files must be deleted immediately after reception, thisis possible by entering ‘-1’ for the number of days. This can be
useful for files which are not used again after automatic reception(such as some SAF files).
Screensaver
Are you tired of your dull Windows screen saver? Click the rightmouse button on the Desktop, click ‘Properties’ and then the‘Screensaver’ tab. Select ‘My Pictures Slideshow’ then, underAcknowledgements
Everything I have discussed in this article has been obtained,
over the course of years, from books, guides, forums, illustrated
magazines, colleagues etc. and it is therefore impossible to list all
the sources here. My apologies for this.
References
1. POVIM Fred van den Bosch, De Kunstmaan, November 2005 page 83
2 KISS‘Keep It Simple, Stupid’
3. Autoruns
http://www.sysinternals.com/Utilities/Autoruns.html
4 WXSIMATE
http://www.wxsim.com
5 Visualcron
http://www.visualcron.com/
6 Macro Maker
http://members.ij.net/anthonymathews/MacroMaker.htm
7 Automate
http://www.networkautomation.com/.
8 GetCharts
http://www.vf0123.btinternet.co.uk/
9 GetRight
http://www.getright.com
10 Free RAM XP Pro http://www.yourwaresolutions.com/

Fred van den BoschYou are about to record a NOAA satellite pass and, at the
beginning of the recording, you notice that the soundcard settings
have been modified by another program. Before you have time toset everything back to normal, part of the transmission has been
lost!
Recognisable? I have discovered a tip to safeguard the recordinglevel you use for saving NOAA APT transmissions as WAV files.
The solution is to download the program Mixer from:http://www.qsl.net/pa1are/software.html

Mixer has several possibilities. After starting you see a number ofsliders (illustration) where you can adjust the sound level for bothrecording and playback. You can store these settings under asuitable name (e.g. ‘satellite’).
If you recall this setting before recording a satellite you can ensurethat the same sound level is always used for recording or playback.
The easiest way is to do this with a batch-file.
Here is the batch file I use for WXtoImg. You can make it using
Notepad and save it in your WXtoImg folder under the name‘wxtoimg.bat’.
The content is:
C:\Program Files\Mixer\Mixer.exe satellite\xwxtoimg.exe

The ‘Mixer’ window

The first line points to the location of the program Mixer, while thesecond line is the program that must be started. By placing‘aptdecoder.exe’ on this line you can use the same method for that
program. For an easy start-up you can create a Desktop short-cut
icon with a right mouse click.
You can initially define the correct sound level, during a ‘live’satellite pass, using the program SatLevel from David Taylor (youcan find it under the Audio Tools section at www.satsignal.eu).
Unfortunately this program cannot be added to the batch file:
WXtoImg and SatLevel cannot be started together via a batch file.
So you must always start this program separately.

www.geo-web.org.uk

25

GEO Quarterly No 11Group for Earth Observation

September 2006

Les Hamilton
At the time of our last report in
GEO Quarterly No 8, the 2005
Hurricane Season was still in full
flow and five additional named
storms, two of these hurricanes,
developed before Nature finallythrew in her cards when Tropical
Storm Zeta finally gave up theghost on January 6 this year.
Beta formed in the southwestern
Caribbean and scored a direct hiton the eastern coastline ofNicaragua as a Category 3
hurricane, whose sustained windsof 120 kph wrecked buildings,
toppled trees and forced
thousands to flee the coastline.
And in neighbouring Honduras,
some 8000 people were
evacuated from 50 communities
north of the Nicaraguan border
after rivers overflowed following
torrential rain.
Honduras was once again thetarget when Gamma developed
off its coast two weeks later.
Again, thousands had to be
evacuated from their homes while
an estimated 50,000 more were
cut off after bridges weredamaged or destroyed, leaving
several cities and towns isolated.
Gamma's heavy rains left morethan half of El Progreso, a city of
200,000 situated on a river near
the coast, under water.
Tropical Storm Delta spent its life
over the central Atlantic where it
posed a threat only to shipping.
During its death throes, however,Delta ripped through Tenerife and
La Palma in the Canary Islands,
cutting power supplies to over
200,000 people and forcing ports
and airports to close. Delta finally
fizzled out over north Africa where
it brought much needed rains to
Morocco.

27th named storm ever, and also
equalled the 1954 record for thelatest storm. Our inside front
cover displays a MODIS image of
Zeta obtained from NASA’s Terrasatellite on January 3, 2006.

Notable Records
The 2005 Atlantic Hurricane
Season was remarkable for thenumber of records it produced. An
incredible 28 storms (table 1)
exceeded the 64 kph threshold
above which they are normallyassigned names. NOAA publicity
declared that there were in fact 28
named storms (figure 1) but the
October 4/5 storm in fact missedout as it was only identified
retrospectively during a postseason review. This storm system
brought gale-force winds to theeastern Azores where Santa
Maria Island reported a ten
minute average of 78 kph on
October 4 with a peak gust of
93 kph.

Name

Dates

Max Speed

Min Pressure

Hurricane(kph)(mbar)(category)1

ArleneJun 8-13

110

989

2
3

Bret
Cindy

Jun 28-29
July 3-7

65
120

1002
991

1

4

DennisJuly 4-13

240

930

4

5

Emily

July 10-21

260

929

5

6

Franklin

July 21-29

110

997

7

Gert

July 23-25

70

1005

8
9

HarveyIrene

Aug 2-8
Aug 4-18

100
170

994
970

10

Jo se

Aug 22-23

90

998

2

11

Katrina

Aug 23-31

280

902

12

Lee

Aug28-Sep2

65

1006

5

13

Maria

Sep 1-10

185

962

3

14

Nate

Sep 5-10

145

979

1

15

OpheliaSep 6-23

135

976

1

16

Philippe

Sep 17-23

130

985

1

17

Rita

Sep 17-26

290

895

5

18

Stan

Oct 1-5

130

977

1

(28)

Not named

Oct 4-5

82

999

19

Tammy

Oct 5-6

80

1001

20

Vince

Oct 8-11

120

988

1

21

Wilma

Oct 15-25

295

882

5

22

Alpha

Oct 22-24

85

998

23

Beta

Oct 26-31

185

962

24

Gamma

Nov 13-20

85

1002
980

25

Delta

Nov 22-29

110

26

EpsilonNov 29-Dec 8

135

981

27

Zeta

Dec29-Jan6

100

994

3

1

Table 1 - Tropical Storms and Hurricanes, 2005 Hurricane Season.
Figure 1 - 2005: A Season of Firsts

This eclipsed the previous 1933
record when 21 storms achieved
Tropical Storm status or greater.
As figure 2 illustrates, the final
storm tally outstripped pre-season
estimates by one third andexceeded the long-term average
by a whopping 250%.

Statistical Records for the 2005 Atlantic Hurricane Season

Previous records are shown in brackets•

15 Hurricanes (12 in 1969)•

4 major Hurricanes hitting the U.S. (4 in 2004)•

4 Category-5 Hurricanes (2 in both 1960 and 1961)•

7 Tropical Storms before August 1 (5 in 1997)•

Costliest ever Hurricane: Katrina, at least $80 billion ($26.5 billion for Hurricane•

Deadliest U.S. Hurricane since 1928: Katrina with at least 1,300 fatalities•

Strongest Hurricane in the Atlantic Basin: Wilma 882 millibars (Hurricane Gilbert,•

Three of the six strongest Hurricanes on record: Wilma 882 mb (1st), Rita 897 mb•

Strongest July Hurricane: Emily, with 255 kph top sustained winds (Hurricane Dennis,•

2-Year consecutive total of Tropical Storms: 42 (32, most recently in 1995-96)

Andrew in 1992)

Tropical Storm Epsilon (later tobecome only the 5th December
hurricane recorded in the past
120 years) formed in the midAtlantic some 1500 km west of
the Azores and spent its entire
lifetime well clear of land. Against
all predictions, Epsilon twice
strengthened to a Category 1
hurricane as it lingered for ten
days.

Recent Trends•

2-Year consecutive total of Hurricanes: 25 (21 in 1886-87)

Finally, a full month after theofficial conclusion of Hurricane
Season (November 30), Tropical
Storm Zeta brewed up 1600 km
west of the Azores. Though it
never posed a threat, Zeta is
noteworthy as the all-time record

The unprecedented severity of the2005 Hurricane Season has givenrise to much discussion as to its
underlying cause. As usual,
alarmists are quick to shout ‘Global
Warming’ or ‘Climate Change’,
pointing out that this heightened•

2-Year consecutive total of Major Hurricanes: 13 (ties with the 1950-51 record)•

2-Year consecutive major Hurricane landfalls: 7 (5 in 1954-55)•

2 -Year consecutive Florida major Hurricane landfalls: 5 (3 in 1949-50)•

3-Year consecutive total of Tropical Storms: 58 (43 most recently in 2002-04)•

3-Year consecutive total of Hurricanes: 30 (27 in 1886-88)•

3-Year consecutive total of major Hurricanes: 16 (ties with 1949-51 and 1950-52)

26

888 mb in 1988)(4th), and Katrina 902 mb (6th)Figure 2 - 2005 Hurricane Season

240 kph in 2005.

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September 2006

Group for Earth Observation

GEO Quarterly No 11

Figure 3b - Number of Hurricanes per Season

Figure 3a - Number of Tropical Storms per Season
hurricane activity in the Atlantic Basincoincided with some of the warmest years
ever recorded world-wide.

1995 and were operative throughout the2005 season. They include:

But the National Oceanic and Atmospheric
Administration (NOAA) totally refute thisargument and state that this enhanced
activity is simply part of a naturally occurring
cycle of tropical climate patterns near theequator. These cycles are termed theTropical Multi-Decadal Signal (TMDS) andnormally span several decades: typically 20
to 30 years although they can last longer.
This means that the North Atlantic tends toexperience alternating 20 to 30 year periods
when hurricane activity may be either above
or below the norm. Figures 3a and 3b plot
the numbers of Tropical Storms andHurricanes since records began in 1851 [4].
And another key point that must not be
overlooked is this: prior to the launch of the
TIROS-I weather satellite in 1960, many
tropical storms and hurricanes that spent
their entire lives over the ocean could havegone unnoticed, skewing the long-term
record. These days, no tropical storm canescape surveillance and detection.

Hurricanes need warm ocean waters tostrengthen and sustain them, and do notform unless the water temperature is at least
26.5°C. Such a temperature is essential inorder to create sufficient atmospheric
convection to elevate moisture 15 km andmore into the atmosphere.

In fact, the global tally of hurricanes andtropical storms in any calendar year
remains remarkably constant, atapproximately 90 ± 10 [5]: increased
activity in the Atlantic almost certainly
coincides with reduced activity elsewhere.
NOAA research shows that it is the TMDS
that is causing the recent spell of increased
Atlantic hurricane activity and that it is not
related to greenhouse warming. The tropicalclimate patterns producing this increased
activity are very similar to those recorded
during the 1920s and late 1960s whenhurricane activity was also greater thannormal. The TMDS manifests itself in
weather events around the world, including
Atlantic hurricane variability, and was also
responsible for the below-normal hurricane
era between1970 and 1994.
The strength of the Atlantic hurricane season
is largely determined by the number oftropical storms that form between Africa andthe Caribbean Sea in an area known as theMain Development Region (MDR),
particularly during the peak months of Augustthrough October.

Key Conditions
The occurrence of an above-normal
hurricane season is not a random event: it
results from interplay between several key
atmospheric and oceanic conditions whichfavour hurricane formation in the MDR.
These key conditions have persisted sinceWarm Ocean Waters

Ocean waters generally were 1° to 1.5°C
warmer than the norm during the 2005
season, favouring stronger hurricanes.
Low Wind Shear
Hurricanes can form only in areas of low
wind shear, regardless of the ocean
temperature, and during 2005 wind shear
was particularly low between the central
tropical Atlantic and the Gulf of Mexico(figure 4).
Favourable Mid-Level Easterly Winds
The pattern of easterly winds blowing off thewest coast of Africa plays a critical role indetermining the strength of a Hurricane
Season. During 2005 these winds
strengthened the tropical low-pressure
systems moving westward across the Atlantic
and also steered them toward the low-shear,warm-water environment of the MDR where
they transformed into tropical storms andhurricanes.
Since 1995 the TMDS has produced lower
wind shear (changing windspeed withaltitude) and warmer waters across thetropical Atlantic; along with conducive winds
coming off the west coast of Africa, this wasa key combination of conditions for the
production of an active Hurricane Season(figure 5).

Figure 4 - Low wind shear during 2005
Very low wind shear (heaviest shading shows the lowest
wind shear) in the MDR (boxed) led to the active 2005
Hurricane Season. Numbers indicate where named
storms formed.
Image: NOAA

Figure 5 - Conditions during 1995-2005
Image: NOAA

An active hurricane regime does, of course,mean that many more tropical storms andhurricanes achieve landfall in the UnitedStates, where, since 2002, there has been
an average of seven such storms annually.
During below-normal seasons, such as theperiod from 1970-1994, relatively few tropicalstorms and hurricanes form in this area.

How the TMDS Affects Hurricanes
The TMDS affects atmospheric and oceanic
conditions in and around the MDR for
decades at a time, key aspects being thewarmer than average waters across thetropical Atlantic, a stronger monsoon in theregion of West Africa and a weaker monsoon
in the Amazon Basin (figure 6). Monsoons
are large-scale seasonal wind and airpressure patterns associated with heavy

www.geo-web.org.uk

Figure 6 - The TMDS and Hurricane Activity
Anomalous upper-level easterlies and lower-level
westerlies produce low wind shear
Image: NOAA

convective rainfall. When convection is strong,warm, moist unstable air in the lower atmosphererises to great altitudes and as it cools on ascent it
forms clouds and rain.
The combination of an enhanced West African
monsoon with a relatively weak Amazon Basin

27

GEO Quarterly No 11Group for Earth Observation

monsoon results in stronger upper level winds but weaker lower-level
trade winds over the tropical Atlantic (figure 6). Such a wind pattern
favours more Atlantic hurricanes by producing lower wind shear in the
MDR. The enhanced West African monsoon is also associated withfavourable westerly winds in the middle atmosphere, yet anotherimportant ingredient for an active hurricane season.

September 2006

tropical Atlantic as the season progresses. In May 2005 NOAA predicted
a 70 percent chance of an above-normal season and updated this to a
95% or greater chance in early August (with the possibility of a nearrecord season). In the event, the 2005 season gave rise to record earlyseason activity with the rare experience of two major hurricanes, Dennis
and Emily forming as early as July, and ultimately smashed almost allexisting records.

Research by NOAA scientists Gerry Bell and Muthuvel Chelliah, currently
in press with the Journal of Climate, describes the TMDS and shows thatit accounts for the entire inter-related set of conditions that controls
decadal hurricane activity. Their study also shows that the TMDS is
causing the observed multi-decadal fluctuations in Atlantic hurricane
activity since 1950.
These results expanded upon a 2001 study in the journal Science [1],which suggested that ‘decades-long cycles in sea-surface temperatures
and wind shear in the tropical Atlantic closely matched the cycles of major
hurricane formation in that region.’ That study also showed the recent
increase in hurricane activity to be nothing new—‘Atlantic Ocean
temperature data shows that this is just the latest manifestation of a longrunning hurricane cycle that dates back to at least 1870’.

The El Niño Southern Oscillation
It was discovered in 1984 that El Niño and La Niña episodes strongly
influence Atlantic hurricane activity. El Niño and La Niña episodes occur
roughly every three to five years and generally last between nine and
15 months. An El Niño event results in a warming of the waters of thecentral equatorial Pacific Ocean while La Niña produces a cooling
effect. These events control the patterns of tropical convection acrossthe central equatorial Pacific, El Niño increasing convection in theseregions while La Niña suppresses it.
Variations in tropical convection affect the wind and air pressure
patterns in the upper atmosphere across the eastern Pacific and also
the winds in the MDR. El Niño inhibits Atlantic hurricanes by producing
upper-level westerly winds and increased wind shear in the MDR while
La Niña promotes Atlantic hurricanes by producing upper-level easterly
winds which decrease wind shear in the MDR.
The combination of El Niño with an inactive hurricane era producesconditions conducive to a below-normal season. This was the casebetween 1970-1994 when every El Niño was associated with well below
normal hurricane activity. By contrast, since 1995, only two seasons
have failed to show above-normal hurricane activity—and thesecoincided with the two El Niño years of 1997 and 2002. Indeed, therecord 1997 El Niño produced a below-normal season.

Seasonal Landfall Predictions
Below-normal seasons average one landfalling hurricane in the UnitedStates, while above-normal seasons average two to three. This increase
is related to the fact that many more hurricanes form in the MDR during
above-normal seasons and that these are then steered generally
westward toward the Caribbean Islands and the United States. As aresult, both regions are at a greatly increased risk of hurricane landfalls
during seasons of above-normal activity.
Whether or not a tropical storm or hurricane strikes the United States
depends critically on the weather patterns present at the time it isapproaching land. For example, when air pressure in the upper
atmosphere is higher than normal over the broad region encompassing
the southeastern United States, the Gulf of Mexico and the western
tropical Atlantic, the wind shear tends to be low and the steering
currents bring stronger hurricanes closer to shore.
This high-pressure region is strongly influenced by the prevailingweather patterns over the continental United States. As this cannot be
predicted more than a few days in advance, seasonal hurricane landfall
forecasts remain an ongoing challenge and it is not yet possible topredict whether any given locality is more likely to be struck by ahurricane than another during a particular season.
During the 4-year period 2002-2005 a total of 13 hurricanes struck theUnited States, an average of three landfalling hurricanes per season,
while eight hit the Gulf Coast and five the East Coast—averages of two
and one per season, respectively.

NOAA’s Seasonal Hurricane Outlooks
NOAA’s research has shown that two prominent climate factors, TMDS
and the El Niño Southern Oscillation (the El Niño-La Niña cycle),strongly control the key inter-related set of conditions governing theformation of tropical storms in the MDR between August and October.
The new understanding of these climate factors means that NOAA canoften predict with confidence how conditions will develop across the28

Figure 7 - Tropical Storm Beryl pictured off Long Island
NOAA-17 HRPT at 15:35 UT on July 20, 2006.
Image: NOAA CLASS Archive (www.class.noaa.gov)

Consensus
There is consensus among a number of NOAA hurricane researchersand forecasters that recent increases in hurricane activity are primarily
the result of natural fluctuations in the tropical climate system known as
the Tropical Multi-Decadal Signal. The tropical climate patterns currently
favouring very active hurricane seasons are similar to thoseexperienced in the late 1920s and the late 1960s when there was alsoenhanced hurricane activity. The USA is currently eleven years into an
active era that began in 1995 and which could easily last another 20-30
years, bringing a high probability that the ongoing high levels of
hurricane activity and landfalls are set to continue.

What lies in store for 2006?
In May this year NOAA predicted an 80% chance of a very active North
Atlantic Hurricane Season for 2006, forecasting between 13 and 16
named storms with eight or 10 of these escalating into hurricanes andthe chance of four to six 'major' hurricanes (those reaching Category 3
or above). The chance of a near normal Hurricane Season was rated as
only 15%.
Although not anticipating a repeat of last year's record-breaking events,
the potential for hurricanes striking the USA remains high. As El NiñoSouthern Oscillation conditions across the equatorial Pacific are
expected to remain neutral during the next three to six months, neither
El Niño nor La Niña is likely to be a factor in determining this year's
hurricane season.
By the end of July 2006 though, only two minor tropical storms, Alberto
and Beryl, had developed (compared with seven last year, three of themhurricanes) and neither of these posed a significant threat. Perhaps we
can indeed look forward to a less stressful Hurricane Season for 2006.
Only time will tell!

References
1 The Recent Increase in Atlantic Hurricane Activity: Causes and
Implications. Science, Vol. 293. no. 5529, pp. 474 - 479.
Stanley B. Goldenberg, Christopher W. Landsea, Alberto M. MestasNuñez, William M. Gray.
2 Multi-Decadal Climate Variability
http://www.magazine.noaa.gov/stories/mag184.htm
3 Active 2006 Hurricane Season Predicted
http://www.noaanews.noaa.gov/stories2006/s2634.htm
4. Data for these graphs from:http://www.aoml.noaa.gov/hrd/tcfaq/E11.html
5. Anthropogenic Effects on Tropical Cyclone Activity
Kerry Emanuel, Program in Atmospheres, Oceans, and Climate,
Massachusetts Institute of Technology
http://wind.mit.edu/~emanuel/anthro2.htm

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September 2006

Group for Earth Observation

GEO Quarterly No 11

John Heath G7HIA
With only a few large electrical storms
each year in Great Britain, it is easy tounderestimate the significance of thisforce of nature, one which has a massive
impact on a global scale. Of the many
thousands of lightning events which takeplace each day, about 80% are discharges
between clouds. The 20% or so that doreach ground can be immensely
destructive. A bolt of lightning reaches
temperatures of around three times thatof the Sun’s surface.
My own experience of a nearby lightning
strike was in 1997 when most of my radio
gear was knocked out. There were no
external signs but just about everything
containing solid state devices failed towork when switched on. The clue to thislightning strike was a PL259 plug on theend of a disconnected antenna lead, which
was firmly welded to a metal radiator.

is probably not something you will rushout to buy. There is a least one Boltek
system running in the UK, atwww.peterboroughwvs.info/stormvue.html

where you can obtain up-to-date
information for up to 375 miles aroundPeterborough. I don’t know who the owneris, but if he or she is a GEO member, andreads this, thanks for making your data
available on the Net. The screenshot
below was a live capture from thePeterborough site on July 7 and shows
intense lightning activity off thethere is a running text commentary giving
the number of storms being tracked, theirintensities, distances and bearings. I havefound that this text feature does not load
every time I log on—it may be a fault withmy computer.
I look in at the Peterborough site mostdays and when there is storm activity I
like to compare the lightning strike mapwith current NOAA APT images which I
capture with my RX2 receiver. I hope youfind that lightning data adds extrainterest to your weather imaging.

Surprisingly, human beings can survive a
strike due to something very much likethe Faraday Cage effect. Instead of taking
a direct route through the body andcausing the explosive destruction often
seen with trees, the lightning tracks overthe moist skin surface. Recent researchusing MRI scanning techniques showsthat survivors sometimes have aspects of
their brain functions altered by the event.
It would be very unwise to underestimate
the danger from lightning if in an open
space during a storm. Good advice iscontained in this little rhyme:
If you hear it, fear it; If you see it, flee it
A lightning discharge produces electromagnetic fields that can be detected overlong distances: a phenomenon that can beused to detect lightning, characterise thetype of discharge and estimate its range
and bearing. The commercial system I am
covering in this article is the Boltek
Lightning Detection System, which seems
to be widely used in the USA and isreadily available. The Boltek website atwww.boltek.com

is well worth a visit, as are the links it
provides, which include research data anda link to Douglas ‘Lightning Boy’
Keisling’s web site, where you can see
some amazing photos of lightning andread valuable hints and tips for successful
lightning photography.
The Boltek LD-250 antenna and detection
package costs around $800 from the USA
so unless you have a serious interest thisPembrokeshire coast. The use of colours
indicates the age of each discharge: yellow
means 1-7 minutes ago, pale orange (8-15
minutes ago) and red (16-30 minutes ago).
This enables a clear picture of theintensity and direction trend of the strikes
to build up. In addition to the map display

The Boltek LD-250 Lightning Detector

www.geo-web.org.uk

The small active direction-finding antennaused with LD-250, which is able to tell fromwhich direction the signal is coming.

29

GEO Quarterly No 11Group for Earth Observation

September 2006

David Taylor
The addition of trial NOAA AVHRR high-resolution data to the
EUMETCast data stream was discussed in the previous issue of
GEO Quarterly and since then, trial dissemination of simulated
EUMETSAT Polar Satellite (EPS) data (MetOp) has been added.
Clearly, both the reception and processing burdens being placedon EUMETCast reception systems is increasing all the time, andthis will continue to mushroom as additional EUMETSAT
Reception Stations are brought on-line and the trial services
become upgraded to full operational status. I recently felt it
prudent to make some tests with my own equipment in an effort
to ascertain what the likely data rates involved might be, andwhether the additional load of receiving EPS data would interferewith existing Meteosat-8 reception by causing missing segments.
For this I purchased an ‘inexpensive’ PC which was on offer from
PC World and beefed up both the memory and hard disk capacity.

Figure 1 - Essential data only during weeks 21 and 22.

Figure 2 - No EPS data from Sunday to Tuesday

The graphs opposite show data throughput from a EUMETCast
test system installed on this PC during May and June 2006.
• During most of weeks 21 and 22 (late May into early June)
the system was operating without an eToken and receiving
only the data for which no licence is required (figure 1).
The average data throughput was some 40 kilobytes per
second (40 kB/s), although it is difficult from the scale ofthe monthly graph to judge this with any accuracy.
• During Monday and most of Tuesday on week 25 (figure 2)
there was no EUMETSAT Polar Satellite (EPS) test data,
and the throughput was typical of many systems receiving
the normal EUMETCast stream. Data flow averaged justover 150 kB/s, peaking at approximately 225 kB/s overeach 30-minute period.
• During the day prior to the screen-shot (figure 3), EPS test
data was being transmitted and, over a 5-minute period,
the maximum throughput was 645 kB/s.
Whilst I am not prepared to put hard figures on this, a rule ofthumb might be that EPS throughput will be at least twice thepresent EUMETCast level, meaning that if you take both EPS
and your present data, expect a three-fold increase in data
throughput.
The relevant details of the test PC are:
• AMID 64 3200+ processor• 2 GB memory• 300MB RAMdisk for the FY file• Windows XI Home• 2 physical hard drives: one for the programs and one forthe data• SkyStar V2.6D PCI DVB card
• SkyStar driveps V 4.3.0a• TelliCast software V2.4.4 B• Also running full MSG Data Manager and AVHRRManager software for data decoding.
• EPS data just kept as files, and automatically deleted after
one day• Each EPS data stream in its own folder• No extra Meteosat-8 segment loss due to EPS data
For Meteosat-8 users, the key outcome is that the addition of EPS
test data to what was being received before caused no extra
segment loss to the standard Meteosat-8 data.

30

Figure 3 - Daily graph showing 5-minute averaged EPS test data

Figure 4 - Tellicast throughput screenshot (in megabits per second)More recent tests and analysis of the data have shown amaximum throughput exceeding 20 megabits per second(20 Mb/s), measured using the TelliCast HTML Shell (figure 4).
Do note that this program uses bits rather than bytes to quantify
throughput.
However, the full IASI (Infrared Atmospheric Sounding Interferometer) data was not being sent during these tests, so the
maximum data rate could be even higher. The tests have also
shown that, for many people who only require the AVHRR highresolution image data from MetOp, the peak rate can be limited
to around 6 Mb/s by using the channel selection, possible byediting the recv-channels.ini file.
Tests with a USB 1.1 TechniSat box showed very little segment
loss (only one segment in 24 hours) when used with the main
services of interest to amateurs—the present EUMETCast data
(Meteosat-8 and regional AVHRR) and the MetOp AVHRR.
However, when the full EPS data were taken, the data
rate exceeded the capabilities of the USB 1.1 interface.
Of course, this is with simulated test data, and not live MetOp
data, so it is a provisional conclusion. Having the ability to selectchannels by editing the recv-channels.ini file is a life-saver in thissituation.
At the time of writing we are still waiting for MetOp to belaunched so these results are a work-in-progress. I would like toacknowledge the help of Arne van Belle, Douglas Deans, and
EUMETSAT during these trial-data tests.

www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

Gérard Kruger F6BEK
If you have an interest in NOAA HRPT
imagery, whether by direct reception or
downloaded from the Internet, you canrender them in 3D by making use of aprogram called 3DEM in conjunction withDavid Taylor’s GroundMap and HRPT
Reader software. Without claiming this tobe more than an initial aid, I’ll to try to
explain as simply as possible theoperation of 3DEM with HRPT images of
the NOAA satellites.
The Software
The three items of software you require
are all readily available, both from theInternet and from Software Showcase(page 42). 3DEM [1] is completely free—
there is nothing to pay and you do nothave to register your copy. HRPT
Reader [2] and GroundMap [2] are alsoavailable as free shareware versions, but
you must use a fully functional registeredversion of each if you wish to prepare 3D
images as explained below. The key
component is 3DEM, software specificallydesigned to drape satellite images over adigital elevation model (DEM) of the
Earth’s surface to give the illusion of a 3D
image.
You will have to create a suitable folder
each for GroundMap and for HRPT
Reader, and then extract their respective
zip archives into these. 3DEM comes with
its own self-install routine. It is also agood idea to have an easily rememberedlocation for your working images—
personally I chose to create a folder named‘satellite images’ inside the 3DEM folder.
HRPT Datafiles
If you do not run your own HRPT station
you can download high-resolution
telemetry files from the CLASS electronic
library of NOAA environmental data at:
http://www.class.noaa.gov

Although you must register before you candownload data from this site, there is nocharge. An article describing in detail how
to select and order your HRPT data waspublished on page 18 of GEO Quarterly
No 5. This process is also described, in
French, on my own website at:
http://perso.wanadoo.fr/
f6bek/nouveau_fichier10.html

The Digital Elevation Model
In order to produce a 3D image we mustfirst obtain a DEM covering the region ofinterest. This is a file containing accurate
data relating to the elevation of the
Earth’s surface. Such data is available
from a number of sources but we will use
the GLOBE data from the NOAA National

Figure 1 - Ordering a GLOBE DEM from NGDC

Geophysical Data Center (NGDC). This isa one-kilometre Digital Elevation Model ofthe entire Earth but you can easily
download a subset covering just the region
you are interested in. The DEMs can beordered and downloaded from:http://www.ngdc.noaa.gov/
mgg/topo/globeget.html

To obtain your DEM, which is provided
gratis, visit this page and click the link
‘Select your own area’ at upper the right toreveal the download page (figure 1). Here,enter the coordinates for the region you
desire, in my case a 16° by 16° area
centred on France and shown in figure 5.
Just edit the values in the four fields fornorth, south, east and west with thecorrect values. All that remains is to typea suitable filename (in the File name field)
and click the Get Data button at the foot of
the page. About a minute later, a set ofthree links appears (figure 2). Download
all three files into a suitable folder (e.g. afolder called ‘GLOBE’ inside your 3DEM
folder).
If you prefer, you can type your e-mailaddress into the field provided and theselinks will be sent to you in an e-mailmessage. Note that you have just 48 hours
to effect the download. If you delay longer
than this you will find that the files havebeen erased.
If any of these files acquires an additional
filename extension during the download
process (e.g. changing to ‘mydata.hdr.txt’),

www.geo-web.org.uk

Figure 2 - The DEM ready for downloading

remove it. The three files must be saved
under the filenames shown in figure 2.
Note: Although you might prefer todownload a much larger DEM, you are
restricted to a maximum of about 40 MB.
The ‘France’ DEM above is a 7 MB file.
Processing the Files

HRPT Reader
The first step is to select an HRPT image
containing a region of high relief that is
free of cloud—and is of course covered by
the downloaded DEM. For the purpose ofthis article, I have selected the European
Alps. The image used in these examples
came from the 13:24 UT NOAA-16 pass on
April 24, 2004. The data file is loaded into
HRPT Reader and, after making sure thatthe overlay feature is switched off, saved
using the ‘Save displayed image’ option
from the <File> menu. Images must be
saved this way in order to save anadditional location file (type ‘.lcn’) whichholds all the essential spatial details

31

GEO Quarterly No 11Group for Earth Observation

Figure 3 - The HRPT segment remapped in Groundmap

September 2006

Figure 4 - The ‘France’ terrain model in 3DEM

Figure 5 - Image overlain over the terrain model

Figure 7 - The final 3D view looking south over the Alps

relating to the image. These are
required by GroundMap in the nextstage of processing.
At this stage there is no reason why
you cannot—within the limits of good
taste—modify the colour balance,
gamma, brightness or contrast of theimage using your favourite image
processing software. Just make surethat you do not rescale it.

GroundMap

Figure 6 - Positioning the cropping tool32

The key to this entire process is theextraction from this HRPT image of asection having exactly the same
coordinates
andgeographicalwww.geo-web.org.uk

projection as the DEM. This is where
GroundMap enters the picture. It
should be noted that the operations
which follow call upon advanced
functions requiring the registeredversion of this program.
Open GroundMap and make thefollowing changes in the<Options/Setup> menus:
Output size
= Giant - 3600 x 2700
Location= User
Map projection = Cylindrical equidistant(zoomed)Next, in the <Setup/General> tab, enter
the coordinates shown below: theseSeptember 2006

match exactly those used when
downloading the France DEM. Check the‘Use my map settings’ box (figure 8).
Open the <Files> menu, select <Openlocation data …> and search in the folder
where you saved the image from HRPT
Reader. The file you must load will havethe same stem filename as that image but
the extension ‘.lcn’. Select this file and you
will see GroundMap work and produce animage with characteristics that you haveselected (figure 3). You must now save itusing the function <File/save image…>.
Save this image in your ‘Satellite images’
folder. By default, this will be called
remapped.bmp, but it is a good idea tosave it with a more meaningful filename.

3DEM
Now the program 3DEM comes into play.
This software makes it possible, inter alia,
to superimpose your satellite image over aterrain model. This implies that, for thetwo files to make a perfect superposition,
they must possess absolutely identical
geographical coordinates. The choice ofparameters used in downloading the DEM
and in setting up GroundMap haveensured that this is the case.
Open 3DEM, open the <File> menu, click‘Load terrain model’ then choose ‘Terrain
matrix’ (figure 9), click ‘OK’ and load theFrance.bin DEM that you stored in your
GLOBE folder. An image centred on
France then appears, as shown in figure 4.
This is your terrain model, which will
have exactly the same geographic
coordinates as the image produced in
GroundMap. You are now ready to overlap
the satellite image over this terrain model.
For the first step select <Operations/F4>
and select ‘No’ in the following popup
message box (you don’t want to convert toUTM projection).
In the ‘Apply map overlay’ window that
follows (figure 10), click on ‘Load’,navigate to the GroundMap image fromyour ‘Satellite images’ folder and open it.
Click ‘OK’ to close the warning box thatappears. Your satellite image now
appears: validate it by clicking the‘Accept’ button.
The satellite image now becomes available
on the working screen, covering theterrain model (figure 5). You can see on
this screen a black square with a notch inthe middle of one edge (the cropping tool).
This square is mobile and resizeable; it isused to define the exact region you wish todisplay in 3D.
Start by clicking over the image (with theleft mouse button) at the position fromwhich you wish to observe the 3D view—
the square will move so that the notch now
stands where you clicked the mouse. The
rectangle itself can be resized/rotated byholding down the mouse on any corner anddragging.

Group for Earth Observation

Next, rotate the box till the centre of theedge opposite the notch points in the
direction you wish to observe thenincrease the size of the visualisation zone
as required. In this example, I haveselected a large selection of the Alps
looking south towards Corsica (figure 6).
Finally select <Operation/F2 3D Scene> tobring up the Terrain Projection
Parameters window (figure 11). The
principal functions are:
1 Legend: the title, which will appear at
the top of the 3D image
2 Projection size: the dimensions
chosen for the 3D image
3 Observer’s altitude: only available if‘Background’ is selected in point 6
below
4 Terrain illumination: select azimuthand elevation for the sun, dependingon the hour of acquisition of theoriginal satellite image.
5 Terrain vertical magnitude: this allows
you to exaggerate the vertical scale toobtain a ‘better’ 3D effect
6 Terrain position: a foreground image
slopes into the distance producing aperspective view; a background view
fills the screen
7 Terrain resolution: min or max(honestly, I haven’t seen any
difference)
8 Terrain type: selects a colour scheme
suited to particular types of terrain
This last item is particularly useful foraligning the image precisely with theterrain model. I recommend that you startby preparing a 3D image for a region
comprising part of a coastline with the<Island/Ocean> option selected. The
resulting image should reveal clearly ifthere is any offset between the terrain
model and the satellite image. If there is,the image can easily be nudged into placeusing the option <Operation/F5 - Adjust
map overlay>. It is advisable to do this invery small steps till the 3D image shows aperfect match.

GEO Quarterly No 11

Figure 8 - Entering coordinates in GroundMap

Figure 9 - Selecting the terrain model

Figure 10 - The map overlay window

You can now change the terrain type backto <Mountain/Plain> and click ‘OK’ to createa perfect 3D image from any region in thesatellite image. Of course, there is a strong
chance that you will not be immediately
satisfied with it; but 3DEM possesses all
the tools to allow you to proceed with any
modifications which you wish.
The 3D image that you create is presented
in a new window which contains two
buttons:• File• Operation
The first is used for saving your work
while the second gives you access to someof the options from the <Operation> dropdown menu:• F1 - allows you to reposition theobservation square• F2 - to modify the parameters used togenerate the 3D image
www.geo-web.org.uk

Figure 11 - Terrain Projection Parameters

33

GEO Quarterly No 11Group for Earth Observation

HRPT Images in 3D

Colour Images... continued from page33

Front Cover
The first NOAA-17 HRPT image from over
the North Pole was transmitted fromEUMETSAT’s new Svalbard at 14:20 UT on
July 18. This image was processed byDavid Taylor using AVHRR Manager and
HRPT Reader software. Read more on
page 22.

• F3 - to modify the colours of theterrain model and text
• F4 - to load a different image• F5 - to nudge the terrain model in linewith the image• F6 - to rotate the scene
After this, it is recommended that you
carry out numerous tests in order tobecome completely familiar with theprogram.
References
1 3DEM can be downloaded from:http://www.visualizationsoftware.com/
3dem.html
2 HRPT Reader and GroundMap
http://www.satsignal.eu
Under ‘Satellite Tools’, click the appropriate
link.

Additional Help
If you require more information about 3DEM
there are numerous websites that provide youwith tutorials and images.
http://www.suissegeo.ch/didacticiels_dossiers.php?page=3DEM
http://ailexhere.free.fr/volvirt11.php
http://perso.wanadoo.fr/
darthmagus/3dem.html
Although the above three sites are in French,
there are plenty more available, in English.
Just search for ‘3DEM’ in your searchengine—you will be surprised.

News in Brief... continued from page22

In 2005 the Intergovernmental Group on Earth
Observations (not ourselves), an international
partnership of countries, the European
Commission and international organisations,embarked on establishing a Global Earth
Observation System of Systems (GEOSS)
within the next 10 years.
So it looks like the prediction, made someyears ago, that there would be a world-widesystem for dissemination of Meteorological
data via commercial satellites is to become areality for all users.

Inside Front CoverNASA’s Terra satellite captured thisdramatic image of Tropical Storm Zeta on
January 3, 2006 through its MODIS
instrument. Despite the date, this was the
final storm of the 2005 hurricane season.
You can read more on page 26.
Image: Jeff Schmalz, MODIS Rapid Response Team

Page 13This true-color 250-metre resolution
MODIS image was acquired by the NASA
Terra satellite at 18:25 UT on June 28,
2006. It shows part of Canada’s northernarchipelago, and features early ice melt in
Simpson Strait between King William Island
and Adelaide Peninsula (see page 40).

September 2006

John Tellick
Being a keen gardener and satellite zapper
can be a bit of a compromise—and I’m nottalking about time.
I have several dishes tucked away atground level on one side of my patio, whichallows easy access for adjustments andthey are out of the way.
Early last year I noticed a rather interesting
plant pushing up from a crack in the patio.
It had dark green feathery leaves like acarrot and looked quite exotic so I left it to
see what developed. Well, it grew and it
grew, getting taller and wider by the week.
Having left it growing that long without
identification I wanted to see if it would

Source: MODIS Rapid Response Team

Inside Back CoverThis colour composite Meteosat-9 image ofAfrica was processed by David Taylor using
his GeoSatSignal-6 software. It was
created using the noon ‘essential data’
imagery downloaded from Dundee Satellite
Receiving Station (see page 16)© EUMETSAT, NERC Satellite Receiving Station,
University of Dundee.

Back CoverRobert Moore sent us this spectacularfalse-colour NOAA-12 HRPT image
obtained from the 15:33 UT pass on May 5,
2006. It displays sun glint extending fromthe Normandy coast, completely around
Britain and north to Iceland. Many of theScottish lochs are highlighted, Loch Nessvery clear
Putting Names to Faces
Four Scottish members photographedattending their annual ‘GEO lunch’ in
Edinburgh : from left - Ian Deans, David
Taylor, Douglas Deans and Les Hamilton.
Photo: Cecilia Taylopr

Cow Parsley (Anthriscus sylvestris)

flower but the trouble was it was growing
close to the front of my Hotbird/Astra-1
multi-dish; the taller and wider it grew theless signal I was receiving.
However, it was now summer and moretime was spent outdoors than messing
around with satellites. Finally it looked likesome flower buds were developing though
they took a time to open as they were quite
large. At last they opened and were flatand quite broad umbels of creamy whiteflowers. It became blindingly obvious what I
had been nurturing (and suffering poor
signals for) all this time.
Nothing but the common cow parsley,
which grows abundantly along road sides
and in fields in the UK.
It was however a very fine specimen andthe flower heads were swarming with agreat variety of insects. But ‘normal
services had to be resumed’ and, withseveral swift snips from my secateurs, it
was!

34

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September 2006

Group for Earth Observation

GEO Quarterly No 11David Tyler
For many years I have been interested inradio communications and have owned avariety of short wave, VHF and UHF
receivers. I had frequently observed
advertisements for weather satellite
receivers in monthly magazines and it
became a logical step forward to research
the availability and viability of entering into
the field of weather satellite reception. Aftera search on eBay, I bid for and won a
Proscan receiver with software, which was
where my involvement with weather
satellites began.
The seller, now a good friend named
Oglivie Jackson from Selkirk, gave me
immense help in setting up for APT
reception. Having seen nothing like it before
I had no intention of going further, but thena suggestion was made that, with WEFAX
coming to an end, I should move forward to
MSG data. Ogilvie said he had progressedin setting this up, but had aged 20 years
and gone grey in doing so.
Now I am in mature in years, with very
limited knowledge of computers and soforth, but with a wife who has someexperience, I went for it and bought my
Skystar PCI card DVB receiver, dish and
LNB from the GEO Shop. I had alreadybeen in touch with EUMETSAT, registered
for the data I required and obtained mylicence from the Met Office. The staff at
EUMETSAT took phone calls from me andsent prompt email returns on every
occasion: just as I had been told, they
couldn’t have been more helpful. One ladyin particular, named Debbie, gave me very
personal service (if that is the right phrase)
and as this was at the time of the World
Cup, I mailed her about Germany losing:
she replied that it did not bother her as shehailed from Brighton!
Once the dish arrived I positioned the wall
brackets myself, having some idea where
the satellite was located, but paid a
tradesman £70 to align it for me. He wascertain it was directed at the correct satellite(Hot Bird), but it fact it wasn’t. It was
actually pointing towards Eutelsat.
Eventually, after airing my problem on the
GEO-Subscribers Yahoo Group, Terence,
another MSG user, came to my help andsorted this problem out—with his help wegot the system all but up and running.
For details about the GEOSubscribers Yahoo Group, seepage iii of our centrefold—Ed.
I say ‘all but’ because trying to run this on
an existing computer in addition to its dayto-day workload was causing conflict
between programs. I sought more help on
GEO-Subscribers, and both David Taylor

and Douglas Deans became involved andadvised me that the answer was to run mysystem over two computers.
I read all the documentation and Help Files
plus suggestions on what to do by theexperts. There is a wealth of information ofDavid Taylor’s website
http://www.satsignal/eu/

particularly Meteosat & ATOVS in the
Weather Satellites section and MSG DataManager in the Satellite Tools section.
A times you can encounter conflicting
opinions, particularly in relation to setting up
the capture software. Some users
recommend installing the software for TV
viewing first (in order to get a fix on thesatellite for dish alignment); others
recommend that you wait for EUMETSAT toconfirm your acceptance and licence. My
own recommendation would be to throw
away the Technisat CD that comes with theSkystar unit and wait to install thenecessary software from the EUMETCast
CD. This will ensure that you are using themost up-to-date software and drivers.
I read Arne van Belle’s comments onchoosing a suitable PC, which can be foundby following the link to MSG Data Manager
on the ‘Satellite Tools’ section of David
Taylor’s website. Under the heading ‘What
PC configurations are supported?’ there is alink called ‘discussion about PC
requirements here’. You can also find it at
this direct link:7
http://www.satsignal.eu/
software/msg_dm_pc.htm

then scroll down to the section headed‘Comments from Arne van Belle’.
In the end I obtained a second (new)computer, exclusively to handle reception
and all the required processing software.
This contained a 2.8 GHz Celeronprocessor, 40 GB hard drive and, initially,
256 MB of memory. I increased the memory
to 750 MB at the time of purchase, thenagain, later, to 1.5 GB when my virtual
memory went low on two occasions. I haveno thought of running 24/7 or, at thismoment in time, creating animations
Of course I had now to consider how toswitch between the two computers with justa single screen so I visited PC World andpurchased a Belkin 2-port KVM switching
device. When I first attempted to install thisunit problems arose, which seemed to bebecause I was using a wireless mouse andkeyboard. This was replaced in case it was
faulty and, finally, I got the system working,with fingers crossed, during a phone call to
PC World.

www.geo-web.org.uk

Another unusual problem I encounteredrelated to the soundcard in the newcomputer (an E-System 102). The
soundcard simply would not work until I had
uninstalled then reinstalled it (thesoundcard being required in order toannounce events).
My wife and I set up MSG Data Manager and
GeoSatSignal with help from our friend
Terence. I also needed two telephone sessions
with Douglas Deans with whom I spent at least
two hours in discussion to resolve setting-up
problems. Configuring an MSG system can bevery frustrating and stressful; you feel braindead at times and it takes over your life—but inthe end I can assure you how well worthwhile
all the effort is.
With MSG safely under our belts we became
ambitious and are looking towards the nextchallenge: of AVHRR and additional package
programs. A 30-day trial of David Taylor’s
AVHRR Manager convinced me that this was
the next and essential step forward. Just lookat the colour pictures that are appearing in
GEO Quarterly magazine (it is worth every
penny) and you will be tempted to go forwardwith AVHRR and achieve these quite
outstanding results for yourself. After only a
few days usage of the trial package we werealready registering for the new services andthe necessary software.
This might be straightforward for some but not
for us. We had trouble getting the code/key
accepted, despite using copy-and-paste, untilDavid Taylor told me I was trying to load it into
the wrong program. I don’t know how he puts
up with me—almost all day on a Sunday,
sending e-mails to and fro to resolve the set-up
and registration details.
I believe it has taken us at least 4/5 weeks
since first approaching EUMETSAT to get thisfar but we have finally made it. Did I lose a few
hairs? I haven’t got much anyway. Did I age 20
years? I can’t afford to as I am 72 now. But
was it all worth it? Yes, It has been in every
sense!
For those of you with past experience andcomputer knowledge it might still give a mild
headache. For everybody else, go for it
because there are people out there who will
give you timeless advice and help—all the way
along.
As David Taylor keeps on reminding us, readthe help pages, join a support group and makefriends along the way. The biggest problem I
have had all the way along is that all the web
pages and help files are written assuming you
understand the terminology, both in regards thecomputer and the satellite imaging. This is not
for the faint-hearted. Many like myself find it
hard to comprehend what Arne, David andDouglas are telling us to do. What is needed isan Idiots’ Guide guide to satellite imaging!

Do you know, I feel I have become anexpert, but I am only kidding myself—it is
all in my mind. Having said that, we haveachieved our goal, the sky is the limit as
they say: make it yours!

35

GEO Quarterly No 11Group for Earth Observation

September 2006

Anders Höök

Anders Höök, who joined GEO earlier thisyear, lives in Vallentuna, 25 km north of
Stockholm in Sweden. He was kind enoughto share the following details of his APT
receiving station with us.
I have just recently turned 70 years of age.
Six years ago, I retired from my job with apower generation company, where my final
post was as a ‘senior analyst’ working withanalysing movements of the electricity pricein the Nordic electricity market, quite afascinating occupation. Now that I am
retired I have got time take up the hobbies
from my youth, which were bothconstructing and listening to radio. I also
once had an R 1155. I have even started tolearn some Spanish in order to try tounderstand something from Latin America.
The upper left hand photograph on the
opposite page shows the equipment I havein my shack. The small upper radio is theR2FX from Holger Eckardt—I bought it
directly from him in the beginning ofJanuary this year. It works very well and I
am very satisfied with it. The possibility tocontrol it from the computer is speciallygood, making it possible to leave the shackand let the images be automaticallyrecorded, something that I do quite often.
The other radios are from top to bottom:
Lowe HF 150, Kenwood R-1000, Fairhaven
RD500VX and AOR 7030 Plus. Those I use
for shortwave listening. In fact I started torecord satellite images with the Fairhaven.
This radio is the one I like the most, even if
the AOR is somewhat better in ‘difficult
situations.’
The image at the far right shows my QFH
antenna. The wire you can see below theantenna is part of an L-antenna for shortwave listening.
The QFH-antenna itself was constructed
after Paul Hayes’ description. A friend ofmine and myself worked a whole day withbending and soldering copper tubes.
Except for a certain amount of noise, I amvery satisfied with it. This problem isprobably unsolvable because there is a

power line about 100
metres away
stretching east andsouth of my QTH.
This gives strong
noise for satellites in that direction.
The NOAA-17 image opposite shows aquite cloudy Sweden on April 14. Parts of
the image with the lowest elevation havebeen cropped because there was quite a lotof noise. This pass had a maximum
elevation of 12 degrees. The more recent
NOAA-18 image is a low elevation passfrom June 28 ranging from 7.5° to a
maximum of 13°. Near the easternmost partof this image, a little below the middle, isthe Yenisey river and some lakes just to its
east. Even farther to the east and quite in
the middle of the image is the Piasina riverwhich flows out near the town Makarova.
Processing was done with WXtoImg, using
MSA enhancement. (Most often I prefer the
HVC enhancement because it gives betterview of the clouds, but in this case MSA
gives a little bit better view of the ground).

Norbert Puetz - email: n100.21113@arcor.de
Norbert Puetz, one of GEO’s German members, has designed ahandy case to keep his APT satellite gear safe while travelling. He
is now hoping to collaborate with an equipment manufacturer withthe view of marketing a complete APT kit in a single package.

Norbert writes ...
I thought that GEO readers might be interested in the neat‘suitcase’ I have made to house my APT equipment when I am on
my travels (photographs on opposite page).
Case contents• TV dipole rod antenna with 50 ohm adaptor and holder tube
• R2FX receiver with battery pack• Sharp MD MT 180 H mini-disc recorder plus spare battery• compass• required cabling
Positive features• suitcase size 38 x 36 x 10 cm• weight: only 1.8 kg• safe and scratch free storage for all the expensive
components• less weight because no sensitive laptop is required• absolute worldwide mobility• lossless data storage with MD recorder (no data compression

36

The ‘suitcase’

because of the narrow audio bandwhidth)• maximum antenna gain (1 dipole) with minimum cable loss
• no antenna mast required
Negative features• system not pager resistant• aircraft radio sometimes causes interference• the antenna has to be moved by hand during reception• the recordings have no timestamp for later processing
The MD-Player has to be a ‘quiet’ one with minimal
electromagnetic interference. Older models sometimes cause
problems by disturbing the R2FX.
The reception has to be performed in a reflection free environment
with no houses and obstructions around.

www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

Anders Höök’s shack (left) and roof mounted QFH antenna (right)

Above: NOAA 17 at 09:08 UT on April 14 (12°)
Right: NOAA 18 at 08:26 UT on June 28 (13°)

Norbert Puetz pictured with his neat portable APT weather satellite travelling case (left) and the packed case itself (right)

www.geo-web.org.uk

37

GEO Quarterly No 11Group for Earth Observation

September 2006

Sally Wannop

Peter GreenWe arrived at the NSC Leicester on the Friday evening after aninteresting drive from Devon to find our friends from Holland alreadysetting up, along with the GEO Shop and Membership stand. One of thegreat aspects of the Symposium is the social side: time to catch up withold friends and to make new ones, to exchange ideas, learn from theirexperiences and tap into to their knowledge. So with this in mind agroup about twenty strong set out to discover the delights of Leicester's
restaurant district. You can't go to Leicester without having a curry andwe found, with the help of Arne's hand held GPS, a restaurant
recommended to Robert Moore. Although we had not booked a table
there was no problem, and we had a great meal in good company.
We awoke to a very bright, warm and sunny Saturday and set off to the
NSC to finish the preparations. I am always amazed at the dedication ofdelegates to the symposium, some arriving from hundreds of miles
away as early as 8.30 am.
The day opened with a brief welcome and introduction from Francis
Bell, followed by the presentation of a EUMETCast licence to the NSC
to enable them to receive MSG data.

Sally, User Services Support Manager at EUMETSAT, stated how very
pleased she was to meet the users with whom she usuallycommunicates only by e-mail or telephone. She opened with an
overview of EUMETSAT and its mission: 'To deliver cost efficient
operational satellite data and products that satisfy the meteorologicaland climate data requirements of its Member States, taking into accountthe recommendations of the World Meteorological Organisation'.This
covered their industry partners, their Space and Ground Segments andinfrastructure, and an overview of their ground stations. Their objectives
are constantly changing to make more environmental products
available, mainly to Met Offices—but the 850 registered amateur users
are also important.
EUMETSAT plays a vital role in providing Geostationary data to theWorld Meteorological Organisation and polar orbiting data will be added
following the launch of MetOp. The Special Application Facility (SAF)
products are designed to encourage member states to gain the
maximum benefit from the satellites.Some countries specialise inderived products that are disseminated either via EUMETCast or fromthe EUMETSAT website.
EUMETSAT is actively exploring the GEONETCast project, which seeks
to provide a whole-world audience with a global network ofdisseminated products, involving partners like NOAA, which would
provide daily data throughout the year in a format based on
EUMETCast. Key updates forthcoming to the EUMETCast service will
include 1-hourly GOES dissemination (which should be in available
Oct/Nov 2006), an increased range of SAF meteorological products andthe inclusion of high-resolution data from NOAA and MetOp satellites.
There are currently 280 users registered for the EARS AVHRR service
and this should expand rapidly as the service comes completely on
stream.
On the conclusion of her talk, Sally was thanked by the audience who
asked her to pass on their gratitude to the members of the Help Deskfor their efficient, helpful and friendly service. I wish all companies paid
such attention to its customers as EUMETSAT.

Pete Green (centre) selling raffle tickets
Photo: Peter J Bradley

Douglas Mansfield
Our first guest was Douglas Mansfield, a senior
weather forecaster from the UK Met Office. Afterobtaining his PhD in Physics at Imperial London,
he did research into boundary layers, polar lows
and thunderstorms off the west coast of Africa
then joined the Met Office in 1979 as a memberof their long range forecasting team. In 1989 hejoined their main office and has now become achief forecaster.

Informal discussions with our Dutch friends during the lunch break

Douglas gave us an illustrated and detailed
overview of the Numerical Weather Prediction(NWP) that is used by the UK Met Office andexplained how the forecasters use satellite
Douglas Mansfield
images. It is obvious that forecasters are never
perfect, but bench forecasters use their experience Photo: Cecilia Taylorof the manner in which the forecast behaves
imperfectly, to modify and improve it, often for distance and time scales
or specific sites which are beyond the scope of the NWP model. This islargely done by mathematical models and the job of the Chief
Forecaster is to interpret the outputs of these models. The Chief
Forecaster offers guidance to other forecasters within the Met Officeand to TV & radio forecasters, as they may interpret the data differently.
Douglas also showed us several examples of the forecaster’s use ofsatellite imagery allied to Conceptual Models to interpret jet streams,
and surface lows. He explained that the Model can be at variance with
their experience and data has to be input by the forecasters to correct
this. By way of illustration he showed us IR images with isobars
depicting strong winds on the rear of surface lows. These he called sting
jets. You would normally expect the strongest winds to be found at theleading edge of a depression but you can get very destructive winds on
the rear—thus called sting jets.

Photo: Ferdinand ValkDavid Taylor
David’s presentation was a software workshop, which was based onquestions raised by users. He explained some of the new data types
coming from EUMETSAT and which can be viewed in Geosatsignal-6.
Labelled F-type products, these are delivered as sectored data whichmust be combined into complete images. David also discussed thelatest versions of some of his other software: MapToGeo, MSG DataManager 2.5 (which now has support for MSG2 data), AVHRR Manager,
the HRPT Viewer, WXtrack and the Kepler Manager.
One useful piece of advice was to turn on Clear Type within
Windows XP, which greatly improves the rendition of screen fonts (Open‘Display’ in Control Panel and on the ‘Appearance’ tab, click ‘Effects’;
select the ‘Use the following method to smooth edges of screen fonts’
check box then check ‘ClearType’ in the list).

Lunch BreakThis year more time was given over to the lunch break, to look over thedemonstrations and to visit the Space Centre. Rob Albas was giving his
normal excellent demonstration of MSG reception using a Linux Box
with his XRIT software, and displayed some stunning images.
continued on page 42 ...

38

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September 2006

Dear Francis,
Many thanks for GEO Q10. Regret that I
haven’t got time to help you out with anyof the vacant roles but you havemotivated me to put finger to keyboard
over your Ku Band Reception behind
Glass/in Loft article.
Firstly, I am delighted that you haverecognised the problem that many of us
have. For practical or cosmetic reasons
it is often impossible to locate receiving
hardware on the roof; instead one either
opts for a permanent loft location or‘temporary for the afternoon’ garden
location, in favourable weather, whensuitable satellite passes are due.
All of my permanent weather satellite
receiving set-ups have been loft-based
under pot/masonry type roof tiles. In my
experience of several different homes, aturnstile or QFH mounted high up in theapex of the loft, well away from metallic
items (e.g. TV aerials, electrical wiring),
works ‘OK’ for APT reception, althoughothers with roof mounted antennas
always seem able to receive longer
passes with less noise. 137 MHz has
similar radio characteristics to stereo FM
radio, which is why loft mounting stillworks but is less superior to rooftop
mounting, especially at low satellite
elevations.
For several years, I mounted my RIG
loop Yagi antenna in the loft to receive
1.6 GHz WEFAX signals. This produced
noisy audio (and thus pictures) whichgave up entirely when it was raining—
either due to atmospheric moistureattenuation or, more likely, a film ofwater on roof tiles increasing signal
absorption. 2G mobile phones operate
at 0.9 and 1.8 GHz and these canoperate effectively indoors in strong
signal strength areas. Geostationary
satellites do not pump out the same
power as a local mobile phone basestation, so results are more marginal.
At 11 GHz (Ku-band) signal attenuation
is a much bigger issue. I’m not anexpert on the physics but my experienceis that a major downpour of rain caninterrupt reception, either due toatmospheric moisture attenuation and/or
a torrent of water running down the dishdistorting radio wave reflection focus to
LNB.
I dare say that the materials-science
industry will have designed some ultralow absorption materials through which
Ku-band reception with a small dish is
possible, but household glass and roof

Group for Earth Observation

tiles are almost certainly too lossy
without installing a Jodrell Bank size
dish in the house!
An externally mounted ‘squarial’ (1980s
BSB UK Ku band antenna = linear
phase array?) would also do the job, butthese are only marginally better thandishes due to their superior visualappearance and lower wind loading.
With the advent of the Internet andalways-on broadband connections withever increasing speeds, one starts towonder for how much longer broadcast(as opposed to point to point) via
satellite will continue. If I can plug into alive stream from Darmstadt through myexisting broadband infrastructure, whybother installing a Ku-band dish with all
the associated hardware and softwareto receive exactly the same data feed?
An idea: Voice-over-IP is now inwidespread use around the world toprovide low cost audio communication
between suitably equipped parties. The
amateur radio community has seized
this opportunity to link repeaters aroundthe world (www.irlp.net). I wonder
whether we in the weather satellite
community could use this as anopportunity to collect real time APT
audio from around the world and makeit available to others. In the European
context this could mean a reception
station in southern Spain receiving a
NOAA as it heads north over Africa andstreaming the audio to users on-line,
who can receive and decode it using
traditional APT audio decoding software.
As the satellite drops below the radio
horizon of the Spanish station, a
Scottish station could take overproviding the audio feed, and thenonward to Norway, Russia, Japan,
Philippines, Australia, etc (or wherever
the satellite travels). I don’t know about
the legal status, but that would be an
awesome experience. I guess that witha network of amateur receiving stations
every 4000 km, all linked to an APT
VOIP network, we could get the planetcovered. What do you reckon?
Actually, perhaps the first thing to dowould be to get appropriately locatedamateurs to collect pictures from thesame satellite as it moves round theplanet and then for someone to jointhese together.
Cheers,
Ben Ramsden (33.4°S 151.1°E)[Anyone with further ideas for pursuingthis line of thought is welcome to send
their submission to the Editor.]

www.geo-web.org.uk

GEO Quarterly No 11

Arne van BelleWindows XP has a System Restore feature
which can be used to return your computer to an
earlier state if you have a system failure or othermajor problem with it.
System Restore automatically tracks changes toyour computer and creates Restore Points
before major changes are to occur. For this it
takes a full snapshot of the registry and somedynamic system files and stores this info in a
‘System Volume Information’ folder on every
local disk.
XP does not recognise the ARsoft
RAMdisk correctly and treats thisdrive as a hard disk drive by default.
If the RAMdisk is too small, System Restore
crashes when it tries to save information on the
RAMdisk. This will cause all restore points todisappear. You can prevent this by excluding theRAMdisk drive letter from System Restore.
Unfortunately, the only way to do this is byediting the registry, so I recommend you tocreate a full backup first (see footnote), then add
the following line and reboot.
Only then you can safely install and activate theRAMdisk without losing System Restore points!
1 Open Regedit and navigate to
HKEY_Local_Machine\System\CurrentCont
rolSet\Control\BackupRestore\FilesNotToba
ckup
2 Choose Edit, new, multi-string value
3 Give the descriptive name ‘RAMdisk’
4 Double-click this, enter “Z:\* /s” in the‘Value data’ field, then click OK (don’t input
the quotes)
Here, Z: is the RAMdisk's drive letter and there
is a space between ‘\*’ and ‘/s’.
Note: Windows 2000 does not use system
restore and does not need this additional setting.
Backing up your Registry
Backing up the registry is easy and a good
guide can be found at:
http://ts.mcafeehelp.com/faq3.asp?docid=68037

Please note that the resulting file (.reg) can belarge (50 to 100 MB).
Also read the note on this link carefully:“If you need to restore the Registry you candouble click on the Registry Backup file you
created. Once you have finished using theregistry editor and are certain everything is
working properly, it is important to delete thebackup file to avoid reverting back to the oldregistry settings. To delete the file, right-clickon it and select Delete."39

GEO Quarterly No 11Group for Earth Observation

September 2006

This composite
NOAA-17 pass was
acquired on
July 20, via
EUMETCast, byDavid Taylor. The
image is acomposite
produced from datafrom both the
Svalbard andLannion stations(locations indicatedon image) and has
a total duration of
22 minutes,
stretching from
10:13 to 10:35 UT.
The image at left
has been takenfrom a screenshotof the AVHRRManager, andvividly illustrates theuninterrupted datathat is now
available from the
EUMETCastEARS-AVHRR
service.

Keith Fraser KC2JC (ex GW3ZVA), a GEO reader from Canada,spotted an interesting feature in a recent NOAA 17 APT image, acquired
over Canada’s far north at 17:15 UT on June 26 this year.
Keith writes: ‘The object of interest is very small but still significant. Near
the top left-hand corner of the main image, the passage to the south ofKing William Island shows as open water (black). I have been observing

40

the Arctic ice for many years and this is the earliest (June) that I haveever seen the passage into Queen Maud Gulf open. Could this be apossible indicator of global warming? The passage is hard to pinpoint so
I have circled it on the enlarged segment above right.’(A 250 m MODIS image acquired just an hour later, and including thisregion, appears on page 13—Ed)

www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

Douglas Deans - douglas@tiscali.co.uk

As is often the case at this time of year
there are few updates to be reported. It isin fact quite noticeable that many of ourbetter known programs have not been
updated for some time. The exception tothis is programs written by David Taylor.
Not only are they continually updated andupgraded but there are exciting new
developments on the horizon associatedwith the up and coming launch of the first
European Polar Orbiting satellite MetOp;
it may be flying by the time you read this.
Hopefully there will be more details about
the new software in the next issue.
Following last quarter’s announcement of
the addition of three of David Taylor’s
well-known programs to the showcase
library, I am pleased to say that a further
one of his programs, GRIB Viewer has
now also been included in CD-GS1. A brief
review of the software is given below alongwith some update news on the very
popular JVComm32.
GRIB Viewer v 2.0.8
Many of the files now being sent via
EUMETCast, and which are alsoavailable from other sources such as theInternet, are in a format known as GRIB
(GRIdded Binary). This is not anappropriate forum to explain the purpose
behind this file format but suffice to say
it was developed and approved by theWorld Meteorological Organisation as anefficient vehicle for transmitting large
volumes of gridded data. Most of us,

including myself, are probably notparticularly interested in this detail but
it is a fact that more and more data is
being sent in this format. What is
important however is that David Taylor
has produced a program which can readthese files and convert them into images.
Most of these files are associated withmeteorological products and products
derived from satellite data.
Some examples of this data include seaice products from the Norway and

Denmark OSI-SAF team. This includes
sea-ice edge, type and concentration
maps. This is available via the
EUMETCast system but in addition there
are North Pole and South Pole productsthat can be downloaded from theInternet. An example of the North Pole
ice concentration map (obviously for thecurrent summer month) produced using
GRIB Viewer is shown in the figure 1.
Also available via the EUMETCast
system are OSI-SAF products from Meteo
France which include longwave

All D avi d Taylor's weather satelli te programs and li brari es, i ncludi ng the current releases of WXtrack,
GS1 Satsignal, HRPT Reader, GeoSatsignal, GroundMap, RX2 PassControl and many other program extras.
This disc also contains a large quantity of sample files, many of high-resolution data, for use with these
programs.
AVHRR Manager
Processes and manages the files for HRPT via EUMETCastv 1.2.4
GeoSatSignal

Manipulates Geostationary weather satellite images

v 6.0.0

GRIB Viewer

Viewer for GRIB format files

v 2.0.8
v 2.0.2

GroundMap

Rescales satellite images

HRPT Reader

Converts raw HRPT data files into images

v 2.6.4

MSG Animatorv 2.5.0

RX2 PassControl

Automatic animation of MSG images following reception
Processes and manages the files received from MSG
satellites
Computer control program for the RX2 receiverv 3.0.8

SatSignal

Creates images from wave files

v 5.0.2

WXtrack

Satellite Tracking Programv 3.5.6

MSG Data Manager

v 2.5.2

A wi de range of software for all aspects of weather satelli te recepti on, i ncludi ng tracki ng, recei vi ng,
GS2 monitoring and image manipulation. Content is detailed below but many other extras are provided. Titles
correspond with folder names. * implies a DOS program.
Collection D02
Recall (wave file recorder), Palette (modifies Wxsat colour palettes).
Scanner recorder v 1.8 (wave file recorder), *NOAA95/*FENG99 (software
Collection D03
for the NOAA 95 HRPT project)
Wxsat (wave file recorder/decoder), Satmon (wave file
Collection D04
v 2.59recorder).
AGSatTrack
Satellite tracking programv 1.33
APTDecoder
CirkitElement Manager

Program for capturing APT audio and processing images
v 1.0.2.70
Documents for the Cirkit Wxsat receiver and the UOSat receiver (PDF
format)2-line element manager
v 1.59

Footprint

Satellite tracking programv 2.10Irfan View

Image/slideshow viewer

v 3.80v 1.40 pre

JVcomm32

Evaluation version (APT/FAX/SSTV decoder)Macintosh kepler editor

Edits verbose AMSAT format elements. Mac OS X and OS9 only.

NeoPaint

Image processing program (30 day evaluation)

OrbitronSatellite Tracking Program

Paintshop Pro

Image processing program (30-day evaluation)

PhotoFiltre

Image retouching program with many extras

v 3.70v 6.1.5

Satscape

Satellite tracker and wave file recorder
v 2.02enerates TLE files in 'Celestrak' style from data sets recovered fromSpace-Track TLE Retriever GSpace Track
Splitter
Utility program for splitting and reuniting large files
WAV file recording and decoding program with many
WXtoImgv 2.7.3
options.
3DEM Package for 3D Terrain Visualisation
GS3 This CD includes the full set of GLOBE Tiles to allow you to produce excellent images and flybys from
HRPT inages. Also included is a selection of Mars MOLA files, sample images and helpful guides by Ed
Murashie.
Image CD
GS4 A wide selection of high-resolution remote images from a range of satellites, including stunning imagery
from the Space Shuttle missions. A full description and source if provided for each image.

Figure 1
North polar ice concentration(The original image is of course in colour)

Mars Rover Panoramics
GS5 A chronological account, in panoramic images, of the NASA Mars Rovers' progress across the MartianTerrainwww.geo-web.org.uk

41

GEO Quarterly No 11

irradiance, solar surface irradianceand a range of sea-surface
temperature products.
There are other products also available
but may I suggest the following web
page for a full and detailed list andexplanation:
http://www.satsignal.eu/
software/grib-viewer.htm

GRIB Viewer is available on GEO
software CD, GS1.
JVComm32 v 1.40 pre
This very versatile and popular
program,writtenby
Eberhard
Backeshoff, is one of the best known
programs for the reception of RTTY,
FAX, SYNOP, NAVTEX and of course
SSTV. At the moment this is a prerelease simply because all the help files
and program additions have not been
fully documented. Onc documentationis complete it will become v 1.40.
It has to be remembered that what you
download, though free, is only a demo
version: all the images it produces areliberally overprinted with the word
‘demo’. To enable full functionality it isnecessary to register JVcomm32 (£44).
This program has been written by
Eberhard in his own free time over a
very long period. I do not as yet have afull list of all the additions and newfeatures but can confirm that they doinclude a ‘repair function’ for pictureswith stair-step type problems.
It has a new NAVTEX, SYNOP and
RTTY messages viewer and runs on
Windows XP without any problems The
program is available on GEO software
CD, GS2. For for further informationand to download the program go to:
http://www.jvcomm.de/Group for Earth Observation

Symposium 2006... continued from page38

Fred van den Bosch was expanding on his
2005 presentation. His use of Digital
Atmosphere scripts and automation of image
reception with David Taylor's software havelead to the development of POVIM
Presentation Manager (see Fred’s article on
page 33).
The GEO Shop was doing great business.
Carol and Clive were kept very busy with items
that had been pre-ordered and, of course, by
those members who just couldn't refuse theexcellent special prizes that were available forthe day.

September 2006

with visiting astronomer Patrick Moore andexplained how, at the schools he attended, heintroduced astronomy. He rounded off with some
excellent photographs taken of his current
observatory.

Concluding BusinessTo end a very busy and packed day GEO held ashort AGM where Francis Bell gave a statement of
the Company's finances and his view of the year
ahead. He also informed the delegates offorthcoming vacancies for Membership Secretary
and the very important post of Magazine Editor.
Various other members of the Management Team
reported on their areas.

Werkgroep Kunstmanen
Ferdinand Valk and Arne van Belle both
entertained us with significant presentations
that appear elsewhere in this Quarterly(Tropical Cyclones, page 5; A semi 2-PC
setup, page 20).

Ferdinand Valk talking about Cyclones
Photo: Cecilia Taylor

Ruud Jansen (left) in conversation with Patrik
Tast, who visited us from Finland
Photo: Cecilia Taylor

Lawrence Harris
Well know columnist Lawrence Harris from
Monitoring Monthly told us why and how he
got into receiving weather satellites from ayoung age. His main hobby has always been
astronomy. But he was becoming very
frustrated to find that the stars were obscured
by cloud. So he took up weather satellites
reception and hasn't looked back. Lawrence
showed us pictures taken from his school days

The finale event of the day was the raffle and I
really must thank all of those who gave so
generously. There were 36 prizes in total,
including an assembled RX2 specially built for the
symposium by Ray Godden and a number of
KVM switches, ideal for those running a 2-PC
system for MSG reception .
The 2006 GEO Symposium was a great success.
Again this year we did not have enough time to fit
in everything that we would have liked nor all thesessions that were requested.
Thank you all for coming. We hope you enjoyed
it? It is always a great honour to greet our friends,
especially those from the Netherlands, who
support us so well. And of course GEO would liketo thank all the speakers for giving up theirholiday weekend to be with us.

What about Next year?
Watch this space and the website.

How to Purchase CDs
Write to the address below
requesting GS1, GS2, GS3, GS4 or
GS5. Prices are £5 for any single
CD, 2 for £8, 3 for £11, 4 for £14 or
all 5 for £17. Please enclose cash or
cheque (made payable to Douglas
Deans - not GEO please) for theappropriate amount. Nothing else isrequired.
The cost includes CDs, packaging,posting and a small donation
towards the cost of overheads. No
fee is asked from overseas
members although an exchange ofsoftware or interesting satellite
images is always welcome.
Orders are normally dispatched on
the day of receipt.
Order your CDs from:
Douglas Deans, 17 Montrose Way,
Dunblane, Perthshire FK15 9JL,
Scotland.

42

Rob Denton captured this storm front over the River Niger in Mali in the 15:15 UT Meteosat-8
channel-12 image on July 18, 2006. Rob considers this one of the best storm images he has seenfrom MSG imagery and was particularly impressed by the front to the right of the storm cloud.
www.geo-web.org.uk

September 2006

Group for Earth Observation

GEO Quarterly No 11

Peter Wakelin
Daichi Watches Merapi
The Directorate of Volcanology and Geological Hazard
Mitigation in Indonesia reported renewed activity at the
2,968 metre high volcano Merapi on Java in early April
2006. Within two weeks a major eruption was taking
place and Merapi was living up to its name which isderived from the words ‘merah’ (red) and ‘api’ (fire).
Japan’s Advanced Land Observing Satellite (ALOS), also
known as ‘Daichi’ in Japanese, which was launched on
January 24 and was still in its commissioning phase at
the time of the eruption, was able to monitor Merapi
every twelve hours. ALOS’s Advanced Visible and Near
Infrared Radiometer type 2 (AVNIR-2) and Phased Arraytype L-band Synthetic Aperture Radar (PALSAR) wereable to make simultaneous observations of the eruption
as it progressed.
These images (right), from JAXA (Japan Aerospace
Exploration Agency), were taken at 02:43 UTC on
April 29 and cover an area about 9 km square.

Merapi

Meteosat 7 Moves East
Following the successful launch of the second second-generation
Meteosat, Meteosat 7 is no longer required at the 0 degree
longitude position and is currently drifting eastwards on a fourmonth journey to replace Meteosat 5 over the Indian Ocean at 57.5
degrees E longitude. A quicker transfer would be possible but thatwould require a greater expenditure of precious fuel needed forstation-keeping manoeuvres at its new location. It is expected tooperate over the Indian Ocean at least until the end of 2008.
Luni-solar perturbations have significantly increased Meteosat 5’s
inclination since its north-south station-keeping ability ended due tolack of fuel. The spacecraft will be switched off and the residual
fuel used to boost it up to a ‘graveyard’ orbit to avoid a possible
collision with an operational spacecraft. Meteosat 5 has been
operating for more than 15 years.
First Satellite for Belarus Fails to Reach Orbit.
BelKA, the first satellite to be owned by Belarus, was one ofnumerous spacecraft destroyed when a Kosmotras-launched
Dnepr rocket from the Baikonur Cosmodrome failed after just 73
seconds of flight on July 26. Built in Russia, BelKA carried a
10-metre resolution multispectral camera and a 2.5-metre
panchromatic camera for Earth observation.
At 750 kg, BelKA was the main payload but 17 other smaller
satellites, some just 10 cm cubes with masses of only one
kilogram, were on board. Several of the small spacecraft
incorporated Earth-imaging cameras, including one from the
Moscow State Technical University, one from the University ofRome and another from the Politecnico di Torino, Italy. Many of the
payloads came from American universities but Norway, Japan andSouth Korea each provided one.
Another Resurs Spacecraft Launched
A new Russian imaging satellite, Resurs-DK was launched onJune 18 into a 70° inclination, eccentric orbit ranging in height
between about 350 and 600 km. The low perigee permits higher
resolution whilst the raised apogee ensures a longer orbital
lifetime. This spacecraft is for civilian purposes but is based on the
Yantar-class military satellites which operate with much lower
perigees.

Launch of MetOp-2 Postponed
MetOp-2 and the Soyuz/ST launch vehicle were returned to thelauncher integration facility at the Baikonur Cosmodrome in
Kazakhstan after a third unsuccessful launch attempt on July 19. At
the time of writing, in late July, a new launch date has not been
determined but an August attempt seems improbable.
Set-back for Indian Space Programme
An Indian GSLV rocket, carrying the Insat-4C communications
satellite, fell into the Bay of Bengal on July 10 shortly after its
launch from the Satish Dhawan Space Centre, north of Chennai.
One of the strap-on motors failed to develop thrust and a destructcommand was sent when the vehicle strayed out of the planned
corridor.
South Korea’s Kompsat-2 Successfully Launched
Kompsat-2 (Korean Multipurpose Satellite 2), also
known as Arirang-2, waslaunched by a Krunichev
Rokot vehicle from
Russia’s northerncosmodrome at Plesetsk
on July 28 into a sunsynchronous 700 km orbit.
Developed and built by theArtist's impression of Kompsat-2 in orbit
Korea Aerospace Research
Credit: KARI
Institute (KARI), Kompsat-2
will provide high-resolution multispectral images of the Korean
peninsula for the production of maps and digital elevation models.
CALIPSO’s Laser Beam Observed from Earth
Several hobbyist visual satellite observers have attempted to see
the green laser light from CALIPSO’s CALIOP instrument (seepage 19) and at least two have been successful. It would seemthat hazy skies enhance the possibility of spotting the thin green
beam and the observer needs to be within about a kilometre of theground track. One observer, just 250 m from the predicted path,reported seeing a green spot brighter than the planet Venus. It
lasted for just a tiny fraction of a second as CALIPSO sped acrossthe sky at 7 km/s.

www.geo-web.org.uk

43

GEO Quarterly No 11Group for Earth Observation

September 2006

Robert Moore

On the second of June I posted a query to
the GEO-Subscribers list about a very
unusual pattern that could be seen in a
NOAA-12 HRPT image of the Irish Sea.
Not only is there extensive sunglint overthe seas to the west of Great Britain, acommon feature during the summer
months, but there is a distinct arc of darkwater embracing Ireland with a ‘tributary’extending through St George’s Channel
then northeast into the Irish Sea. Les
Hamilton replied with the following
observations:‘I have looked at all the HRPT channels
and note the following:• The strong pattern of dark splodges isapparent only in channels 1 to 3
(those reflecting visible light).
• The pattern does not show up oneither of the radiated IR channels(ch 4 and ch 5).
• The pattern clearly owes its existence
to the pronounced sunglint, whicharises from the fact that the solar
radiation hits the region at asignificant angle (the sun is low in thewestern sky).
• The NOAA 18 image earlier in theday, showed the Irish Sea without any
tonal modulation whatever in all
channels (i.e. totally black in thevisible channels)‘Now strong sunglint requires a smoothsea surface; so the implication is that thedark splodges, most significantly thebroad ‘river’ between Wales and southern
Ireland, result from disturbed water thathas lost its ability to produce a strong
NOAA 12 channel-2 HRPT image - 15:40 UT - June 2, 2006

specular reflection. Could this be due tolocal, low level winds, blowing through thechannel?’One other explanation occurred to me: I
remember from my days at sea (I used tohave a small ship in the Irish Sea) that thetide turns very rapidly and that there can be
turbulence in the surface water, especiallyin the gap between Ynys Mon (Anglesey)
and the Irish coast. Tide tables confirmedthat the tide was indeed on the turn when
this image was received and perusal of theAdmiralty chart confirmed that there was
likely to be a sudden change in the
direction of the tidal stream—and possible
eddies—at about the point where the darkwater began in the HRPT image.
The NOAA-12 channel-4 IR image

44

What seemed less plausible was that the

www.geo-web.org.uk

disturbances in the water at this point would
continue so far to the southwest and turnaround the extremities of England and Irelandthen up the Channel and west coast of Ireland.
But it was worth a quick look if only toeliminate this possibility. An examination of theAdmiralty Tidal Stream Atlas for the Irish Sea
and Bristol Channel led me firmly to reject the
hypothesis that the effect was caused by thetide. Les’s suggestion that this could be wind
disturbance seems more plausible—thoughagain the shape of the disturbance does notreally support this idea very strongly. I wonder
if any readers of GEO Quarterly have any
ideas about this odd event?

Reference
1 Admiralty Chart Irish Sea with St George’s
Channel and North Channel, Taunton, 1988
2 Admiralty Tidal Stream Atlas; Irish Sea andBristol Channel (NP-256), Taunton, 1992.