Group for Earth Observation

The Independent Amateur Quarterly Publication for

Number 5

Earth Observation and Weather Satellite Enthusiasts

March 2005

Inside this issue . . .
‘The Union County Glacier’
Read about the day when aglacier developed in New
Mexico, USA
Upgrade your RX2 with
GEO’s customised PIC for
the new NOAA-18
frequencies ...

... read about it in thearticle on page 16
Rob Alblas describes his
XRIT2PIC software fortranslating Meteosat-8transmissions on page 28‘Farewell Meteosat Welcome Meteosat’. John
Tellick reviews 25 years of
the Meteosat programme
Create superb HRPT
images using telemetry files
from NOAA’s Satellite
Active Archive
More on setting up an MSG
system from Fred van den
Bosch

The 2nd GEO Symposium takes place in the
National Space Centre, Leicesteron April 30, 2005. Full details inside.

How LIDAR is used tomonitor Mount St Helens
Plus all the regularfeatures ...

This image of Europe was taken from the 10:15 UT Meteosat-8 transmission on May 22, 2004 by Cedric Roberts.
The final image has been corrected to Mercator projection to give a more realistic view of NW Europe by the latest Dartcom software

The noon Meteosat-8 image from December 29 last year, overlain with synoptic data using Digital Atmosphere.
You can learn how to achieve this in Fred van den Bosch’s article on page 44.

Heinz Fischer from Immberg in Germany sent us this 12:30 UT Meteosat-8 image from October 10, 2004, showing two impressive
depressions on the same image, one over the Bay of Biscay, the other approaching over the Atlantic.
Image © EUMETSAT 2004

The main board of the RX2 receiver showing
the new PIC in place at upper right.

This photograph of a built RX2 kit in a customised case wassubmitted by Norbert Puetz from Erding in Germany.

As this issue of GEO Quarterly goes topress, the world is still struggling to cometo terms with the greatest natural disaster inliving memory: the Indian Ocean earthquake
and resulting tsunamis which devastatedsoutheast Asia, Sri Lanka and India. The
high-resolution IKONOS satellite images on
page 17 can only hint at the devastation on
the ground. Our thoughts go out to everyone
who has been touched by this event.

G

EO readers will be saddened to learn of the death of CedricRoberts MBE, who contributed articles and weather satellite
images to a number of periodicals, including GEO Quarterly. Cedric
was a mine of information on all aspects of weather and satellite
observations, and was always delighted to share his knowledge andexperience with others. We are all very much the poorer for his
passing. Dave Wright and Alan Davies have compiled an appreciationof Cedric which you can read on page 6. A selection from the final setof images Cedric submitted to us is also published in this issue.

As you will discover on page 45, a number of GEO readers havevolunteered to add their names to the GEO Helplines section. The
GEO Management Team would like to take this opportunity to express
their thanks to all involved.

T

his issue sees the opening of the GEO Shop, managed by Clive
Finnis. We have just two items available this quarter, but hope toincrease our range during the months ahead. RX2 users wishing toaccess the new NOAA-18 frequency may be interested in our
inexpensive new PIC whilst new overseas readers can save on backissue costs with our CD offering the four 2004 GEO Quarterlies in PDF
format. You can find the GEO Shop section on page 46.

Contents
GEO Report
Francis BellGEO Symposium Leicester
How to find your way to the Symposium
Quarterly Question
Francis Bell
Colour Cover Image Details
Known Meteosat Image Anomalies
EUMETSAT
Cedric Roberts MBE
D Wright, A Davies
Add Cloud Top Temperatures to your Images
Mike RoweLIDAR - Monitoring Mount St Helens
NASA/USGS
Problems Making Antenna Measurements
Rob Hollander et alUpgrade your RX2 with GEO-PIC 1.0
Clive Finnis
HRPT Images from NOAA Active Archive
Les Hamilton
Earth Imaging News
Peter Wakelin
Miami Conference Report
Francis Bell
Useful Internet Discussion Groups
Copy Deadline for GEO Q6Contract for MSG-4 Signed
NASA’s Other Earth Observing Spacecraft - part 2 Peter Wakelin
B-15A Iceberg Blocks McMurdo Sound
XRIT2PIC - a tool to generate MSG images
Rob Alblas
Miniaturised WEFAX Receiver for Meteosat-7
Jaap Rusticus
Farewell Meteosat .. Welcome Meteosat
John Tellick
How far East can you See
Robert Denton
The Union County Glacier
Freak Storm Ravages Paris
In Tray - Readers’ Letters
Imaging away from HomeJohn Heath
Software Showcase
Douglas Deans
Weather Predicting Simplified: Book Review
Peter Bartlett
My Experiences Setting up an MSG System
Fred van den BoschGEO Helplines
GEO Shop/Back Issues
GEO Membership Renewal FormNOAA Satellite Pass Predictions

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3
4
4
4
5
6
9
10
13
16
18
23
24
25
25
25
26
27
28
31
33
35
37
39
39
41
42
43
44
45
46
47
48

GEO is led by
Francis Bell
Clive Finnis
Les HamiltonPeter Wakelin

Nigel Evans
Ray Godden
John Tellick

CONTACT INFORMATION
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
Articles and Images for Publication
Les 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
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

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
Toptown Printers, Vicarage Lawn,
Barnstaple, Devon EX32 7BN.
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 published designor any constructions carried out by members orother third parties.
Copyright GEO © 2005
The contents of this Quarterly remain theintellectual property of the Group for Earth
Observation Ltd. and its contributors. Copying oftext or images, either from the printed Quarterly
or from any electronically stored source, isforbidden without permission from the editor.

GEO Quarterly No 5

Group for Earth Observation

March 2005

Francis Bell

People who have sat around a committee
table with me at meetings know I often
say that I am aware of yesterday but I’m
more interested in tomorrow. GEO is now
a little over a year old and it would beeasy to go back over our achievements inthat first year. I will not try to do thatbeyond one sentence. Membership is
running at over 500 in 30+ countries, wehave published four quality magazines,
held a symposium at Leicester, spent
three days demonstrating at AMSAT in
Guildford, attended rallies at home and in
Utrecht and finally participated in fourdays with NOAA in Miami, all supported
by a talented management team. We
must look to the future.

Francis Bell pictured welcoming a delegate
to the GEO stand in Miami

New Satellites
If I have this correctly, two new satellites
will become available in 2005, MSG-2
and NOAA N (18); others I just don’t know
about, for example the latest Sich. One
thing I do know is that our interest group,
many of us as direct readout users with acuriosity for experimentation, have a
wealth of information for receiving weather satellite signals and can perhaps makecontributions that commercial organisations and national meteorological offices
could not support.
New Services
This philosophy is supported by our policy
for the coming year when GEO will be
developing further services to members in
the form of availability of reception hardware and software. Clive Finnis will berunning this for GEO together with theestablished services run by Douglas
Deans. Our first GEO Shop page can beviewed on page 46.
Symposium 2005
Again, looking at the coming year, our

2

symposium at Leicester is booked andyou can learn full details on the next page.
Please support it if you can.
I think we enjoy a good relationship withAMSAT-UK and I hope GEO will be
invited back to Guildford this year.
Attendance at UK rallies is still a matter oftime for individuals and policy. I willcertainly try to return to Utrecht for at least
one of the Dutch Werkgroep Kunstmanen
meetings.
Education Coordinator
An aspect of GEO membership that I
always find rewarding is the willingness ofmembers to contribute to the group. If you
have read previous issues of ourQuarterly you will know that I have been
asking for someone to look after theeducational dimension of our group. I am
an ex-teacher and feel a passion to share
our skills and interests with the education
sector. I was so pleased when David
Painter offered to undertake this role. My
personal thanks to David. Who knows
what future developments there may be?
All I know is that children are inquisitive.
Here’s a quote from my bright three year
old grand-daughter a few days ago:
‘Grandpa! Why does it get light and darkeach day?’ Children want to know thesethings.
International Liaison
There is another role that I would likesomeone to fulfil. It’s the international
dimension. I was astonished to learn from
Nigel, our membership secretary, that
GEO has members in about 30 countries.
That does indicate the international
nature of our interests which transcends
national boundaries—we are a group for‘Earth Observation’. I would likesomebody to offer to take on aninternational role. I think this could be a
rewarding job without any stress.
Whoever does fulfil this role would identify
technical publications or user groups infields such as amateur radio, TV,meteorology, electronic construction etc.
anywhere in the world and send them a
GEO press release plus, perhaps, a copyof one of our Quarterlies. GEO could draft
the press release and invite its publicationin any technical or related journal in any
part of the world. If you don’t know about
GEO then you can’t join.
www.geo-web.org.uk

Technical Matters
There are technical issues which ourdirect readout membership will need toaddress in the coming year. These
include LRIT and, in the UK, possible RFpager transmissions within the 137 MHzband which may interfere with thereception of NOAA 18.
Subscription Renewal
I know I am at risk of repeating myself but
our first year cycle elapses with this issue
and GEO subscriptions will shortly
become due on a rolling programme. For
GEO to remain financially viable we need
your membership. Without it there is no
point in continuing. If you don’t wish to
renew, that’s fine, but to give us feedback
please let me know why. E-mail or post tome—but better still, just renew. A renewal
form can be found on page 47.
StaticI have recently bought a new car (well it’ssecondhand but new to me). I’m very
happy with the car but I have noticed that
often, when I get out of it and close thedoor I get a static shock. I can sometimes
hear a click and it always takes me bysurprise. I now close the car door with myelbow on the driver’s door window.
The issue is this. On GEO business I
often take my computers to exhibitions
rallies club meetings and otherdemonstrations. Can anybody tell me
about the risk from static of loading andunloading a computer from a car. I do takestatic precautions when handlingmicrochips; I touch metal water or gas
pipes before handling microchips but I
can’t do that when getting out of a car. Are
my computers at risk? Copy to the editor
please. This is not a trivial question and I
really would like to know if there are risks.
I know some cars are fitted at the backwith a conductive trailing strip touching
the ground. Do these work and should I
have one fitted? I know they say such
strips prevent travel sickness but I am
totally dismissive of that analysis. Try
travelling on a coach with 52 teenagers,
bucket in hand, and tell the children thecoach is static protected!
On behalf of GEO’s management team:‘Best wishes for 2005’.

March 2005

Group for Earth Observation

GEO Quarterly No 5

Francis BellGEO's annual symposium has been
booked at the National Space Centre(NSC) in Leicester on April 30, 2005.
Those of you who have been before knowthat this is an outstanding venue withgood facilities for a meeting such as ours,
offering technical support for live satellite
reception and our workshops as well as
an exhibition area. In addition, there are
the NSC's own extensive exhibition halls
which could take a day to look around(registration for the symposium includes acomplementary ticket to visit the NSC
exhibition area).

or question that a member wishes to beraised or discussed on the day, please letme have it in writing ASAP and I will
present it to the meeting. I promise thatany correspondence I receive, whether
critical or complimentary, will be read tothe meeting and discussed as
appropriate. Delegates may also raise
any matter on the day.
You can contact me by e-mail at:
francis@geo-web.org.uk
or by post at:
GEO
Coturnix House, Rake Lane,
Milford, Godalming,
Surrey GU8 5AB
Telephone ++ (0) 1483416897
Registration

The packed lecture area during Symposium 2004

The programme for the day has yet to be
finalised but will be similar to last year.
VIP guests have been invited but until
definite replies have been received it is
not appropriate to include them in the
programme. However, I am hopeful thatboth EUMETSAT and the UK Met Officewill be represented.

If you wish to attend our Leicester
Symposium please register with Francis
Bell either by e-mail, telephone or post
(details above). The cost for the day willbe £12.00 and this will also cover theentrance to the NSC's exhibition area
(normally £8.50 anyway). I cannot thinkof a better value for money day.

subsequently uncertain about
attendance please let me know.

yourThe day's events are open to all
GEO members and their guests.
Please encourage non-members
to attend because this does help topromote GEO. Because the cost isquite small, please pay at theregistration desk on the day.
Presentations etc
If any GEO member would like to makeany sort of presentation or equipment
demonstration at Leicester this would bevery welcome—no more than that, but
definitely encouraged! I think thatmembers’ willingness to share skills andexperiences is one of GEO’s greatest
strengths and was certainly in evidence atlast years symposium. Please do not be
shy at offering: you will be talking tofriends who share a common interest.
Please contact me and I will ensure you
have exhibition space or a slot within the
programme.
Information
For maps and details about the NSC
please visit their web site atwww.spacecentre.co.uk
Closer to the date, visit GEO's web site

The day will of course include talks,presentations and demonstrations of live
weather satellite reception. If the new
NOAA satellite has been successfully
orbited, we may be able to receive live
reception of NOAA-18 using GEO's new
PIC chip, and we will certainly bedemonstrating live Meteosat 8 reception.
We will also have workshops forbeginners and experienced alike andopportunities for conversation and sharedexperiences with friends.
Towards the end of the day we be will
have a plenary session which will include
GEO's AGM, where any issues relating to
GEO can be raised and discussed.
Reports and accounts will be available,
together with the rules and legal structureof GEO which govern our responsibilities.
Remember that GEO is a company inEngland and Wales, with corresponding
legal responsibilities, which we fulfil.
I know that not all members will be able tocome to Leicester so if there is any issue

http://www.geo-web.org.uk
for details of the day's programme.

A Meteosat-8 demonstration at Symposium 2004

Any problem will be one of time: fitting
everything into one day. Costs of travel,
food accommodation and other personal
expenses are not included. I will use the
Ibis Hotel for my accommodation on thenight before our meeting. This hotel isclose to the centre of Leicester and also
close to the railway station. For the sakeof planning I would like you to registerwith me via any of the above contact
points: this is because there is an upper
limit to the number of delegates we canaccept. I don't expect a problem here butit helps to know how many people will be
coming. It also allows me to prepare adelegate list. If you do register and are
www.geo-web.org.uk

The official start time is 10.00 am but
setting up can begin at 9.00 am. We must
finish by 6.00 pm. Our symposium rooms
are below the NSC's offices and easy tofind.
Please come to Leicester if you can.
Last year's experience indicates that
it will be a worthwhile day but itneeds membership support.

Member participation during a break in proceedings
at Symposium 2004

3

GEO Quarterly No 5

Group for Earth Observation

March 2005

The National Space Centre is located just off the A6, two miles northof Leicester City Centre, and midway between the city’s inner andouter ring roads.
Brown signs carrying a spaceship motif direct you from junctions 21,
21a and 22 on the M1 and all other arterial routes around Leicester.
There is free parking for 400 vehicles at the Space Centre.
Midland Mainline and Central trains serve Leicester station. Bus
route 54 serves Leicester Station, City Centre (Haymarket Bus Stop,
Stand 14) and Abbey Lane, the latter just 5 minutes walk from theSpace Centre.
You can find more information about shuttle buses serving the Space
Centre by telephoning Leicester Tourist Information Centre on(0116) 299 8888.

Location of the National Space Centre (not to scale)ball (I measured one at 63 mm), could I fit it into my sitting roomwith me standing at one end of the room? The answer surprisedme.

I will risk setting one more question andthen invite GEO's membership to submit
questions for publications. Questions to theeditor or to Francis Bell please.

Francis Bell
There was a question in our last Quarterly, GEO Q4, relating to
the sun and its distance from the Earth. Taking the mean
distance from the sun to Earth as 150 million kilometres, howmany solar diameters are we away from our sun? I had
previously worked out the answer.
As promised I picked the winning entry on December 25, 2004.
It came from Bert Harms from The Netherlands. He (or his
nominee) wins a free entry to our Leicester symposium on April
30. His entry identified the sun as subtending an angle of 0.5
degrees as seen from the Earth. So the calculation is :Sin(0.5°) x 150 million equals 1.305
Therefore the solar diameter = 1.305 million kilometres
150 million divided by 1.305 gives a distance of 115 solar diameters.

[Strictly, this should use tan(0.5°) rather than sin(0.5°), but
for angles smaller than 2° the difference is negligible — Ed]I had previously cheated. I looked up the solar diameter in areference book which said it was 1.4 million km. The answers
are very close.
The reason behind this question related to my comprehensionof distance and putting zeros on the end of a number. I can do
the mathematics with exponents but with millions and billions I
begin to lose reality within my brain. But I can cope with 115.

The Question:
Assume that all Earth's oceans could be spread evenly over theplanet's surface to an average depth of 6 km (which would beapproximately true). If all the atmosphere were compressed to a
volume at mean sea-level pressure, what would be the volume
ratio of sea to atmosphere? Hint: 'What is the atmosphericpressure on the top of a 6,000 m high mountain?' Answers toFrancis Bell please, by e-mail or post.

Cover Colour Image Details
Front
This splendid Moderate Imaging Spectroradiometer(MODIS) image of Scotland was acquired by NASA’s
Terra satellite on December 19, 2004 and shows snow
covering most of the Scottish Highlands. The Great Glen,
which includes Loch Ness, is visible as a dark diagonalline bisecting the region from lower left to upper right.
Credit: Jeff Schmalz, MODIS Land Rapid Response TeamBack
A true-color (MODIS) image from NASA’s Terra satellite
showing Von Karman Vortices tracking southward fromJan Mayen Island, north of Iceland, on September 23,
2004.

This was my next calculation. If the sun were the size of a tennis
Credit: MODIS Land Rapid Response System

4

www.geo-web.org.uk

March 2005

Group for Earth Observation

GEO Quarterly No 5

Occasionally, certain images produced by Meteosat
weather satellites display degradation due to theintrusion of sunlight into the radiometer. Thisphenomenon is dependent upon the sun-Earth-satellite
geometry and is unavoidable at times. It generally occurs
when the sun is not in complete eclipse behind theEarth—as viewed from the satellite—so that a portion of
the sun’s disc is visible from the satellite, behind theEarth’s northern or southern limb.
This effect is observed particularly around midnight andespecially during the time of the eclipses in spring andautumn. Visible light, infrared (IR) and water vapour(WV) images are all susceptible to degradation.
The light spots detected in visible images are caused bydouble reflections of stray light due to the optical designof the Meteosat radiometer. As direct sunlight reaches thesatellite it is reflected and diffused by the mechanicalstructures within the radiometer. The consequence of thisis that stray light enters the radiometer field of view,
reaches the detectors and creates intense bright spots insome images (figure 1).
In the case of IR images, the degradation takes the formof a dark area (figure 2). When the radiance data areconverted to temperature readings this gives excessively
high values. Users analysing such images for thoseparticular time periods should be aware of this anomaly.
Another manifestation of the anomaly is found in the WV
images where 'dark spots' and 'bow-shaped structures' canbe observed, both features being clearly evident infigure 3. If the effect is too severe, the acquired Meteosat
image will not normally be disseminated; however,images displaying only minor defects are made available
to users for the sake of completeness. An additional typeof anomaly also sometimes detected on WV images is a
'striping pattern', as illustrated in figure 4.

Figure 1 -A Visible light image taken near
midnight on August 25-6, 1997

Figure 3 -Figure 2 -A dark area can be seen over the Baltic Sea at upper
centre in this IR image taken at midnight on April 16, 1997

Acknowledgement
This article summarises information provided on the
EUMETSAT website at:
http://www.eumetsat.de/en/area5/anomalies/anomalies.htm

This web page also features a number of interesting loop
sequences that illustrate the effects rather well.

A WV image showing‘spots’ and ‘bows’

www.geo-web.org.uk

Figure 4 - A WV image showing ‘stripes’5

GEO Quarterly No 5

Group for Earth Observation

March 2005

Compiled by Dave Wright from information provided by Alan Davies, a close friend of Cedric Roberts MBE.
It is with much regret and sadness that we learned of thedeath of Cedric Roberts MBE, who passed away
peacefully in Mary Stevens Hospice, Stourbridge, West
Midlands on November 27 last year. Unfortunately, while
he was undergoing a pain management program in the
Hospice, Cedric became very ill and lost his valiant fightagainst the slowly progressive cancer which he had
endured for several years.
Cedric was born in 1931 in Halesowen, West Midlands
and, apart from National Service in the RAF, lived all his
life in Halesowen. After entering the Forces he did his
basic training at RAF Locking then spent his two years of
National Service at RAF Scampton, Lincolnshire, where
he worked as a Radio/Radar technician, mainly on
Lancasters.

Taking temperature readings at Halesowen - May 1997

Cedric Roberts pictured taking a rain-gauge reading in May 1997

Cedric was not involved directly with meteorology whileat RAF Scampton but the Met Man did want to be a radio
man, and Cedric wanted to be the Met Man: they did try
to swap but the RAF would not agree!
After completing his National Service in the RAF Cedrictook up his chosen career in education and taught physics
and mathematics at Three Dwelling’s School, Halesowen
and latterly at Windsor High School, Halesowen up until
1986 when he retired as Deputy Head Teacher at the ageof 55.
Cedric became intensely interested in all aspects ofmeteorology from an early age and at the time of his death
had maintained continuous weather records for a periodof 57 years. He had been involved with computers since
the introduction of the first BBC Micro and once spenttwelve months transferring forty years of written hardcopy data on to spreadsheets. As technology advanced hebecame particularly interested in weather satellite
systems.
6

Before his illness took a real hold, Cedric used to go about
giving ‘talks’ to local groups on the weather; these werecomplemented by excellent slide presentations. He was akeen photographer, particularly of cloud formations, andthese photos were all taken by himself.
Cedric was awarded the MBE for ‘Services to Meteorology’
in March 1998.
Over the years Cedric contributed numerous interestingarticles on both weather and weather satellite imaging toa variety of publications. He was a contributor to the
Launch Issue of GEO Quarterly and provided the striking
Meteosat-8 image for the cover of issue no 2.
The Halesowen Climatological Station (DCNN 4839)
operated by Cedric was a Volunteer Observer Station for
the Met. Office and provided daily observations to themfor many years. BBC Midlands TV frequently used hissite for live interviews if any extremes of weather had
occurred.
The weather observations were Cedric’s life and tookprecedence over everything else. It is amazing that hemanaged to continue this work throughout a long illness,right up until three weeks before his death.

www.geo-web.org.uk

March 2005

Group for Earth Observation

Cedric Roberts regularly submitted collections of hisweather satellite images to GEO, always accompanied byinteresting observations. The two images on this page are
typical, and were selected from the most recent batch hesent us. Cedric wrote: ‘This rather nice image featuring
the Straits of Hormuz (above) was obtained from
Meteosat-8 at 13:30 UT on May 28, 2004. This image
shows up the convective activity very well. Whilst
experimenting with a beta version of new software I

GEO Quarterly No 5

happened upon this rather unusual image of a sandstorm
blowing from the southern tip of Saudi Arabia into theIndian Ocean (below). It was taken from the 12:00 noon
Meteosat-8 image on May 23, 2004 and was processedwith Dartcom software. I think you will agree that it israther an unusual image, diverging from the usual
pattern of images coming from this satellite, with its
astonishing definition.’

www.geo-web.org.uk

Images: © EUMETSAT 2004

7

The ‘Great Storm’ that assailed parts of Great Britain with 200 kph winds on January 11, as seen through the sensors of NOAA-17 at 22:01 UT.
Channel-2 infrared image created using HRPT Reader software from telemetry data supplied by David Taylor

March 2005

Group for Earth Observation

GEO Quarterly No 5

Mike Rowe

August 16, 2004 was the day that an unprecedented flash
flood brought disaster to the small Cornish village of
Boscastle. In just two hours the total August rainfall of
75 mm fell over the area, causing two nearby rivers toburst their banks sending a torrent of water through thecentre of the village. Several homes were destroyed, over
50 vehicles carried off by the floodwater were written off,
and in all the damage was estimated to be many millionsof pounds.
Mike Rowe sent in two NOAA-12 satellite images of theevent, one of them with an overlay of cloud-top
temperatures, which show more clearly the extent of therain cloud. GEO invited Mike to describe his technique forthe benefit of readers.
Mike writes:
I use a registered version of Satsignal and loaded the
additional colour look-up tables (LUTs) available fromDavid Taylor’s website [1]. When Satsignal is run you now
get a new option in the NOAA colour section, HLS_CT.
This option, together with the normal HLS one, were used
to obtain these pictures, acquired from NOAA-12 at
15:25 UT, close to the time of the storm
Figure 2 - The same image, processed using the ‘HLS_CT’ LUT

For the record, I am located near Worthing in West
Sussex. My receiver is an RX2 and the antenna is a QFH
mounted on a pole in the back garden, approximately
6 metre above ground and about 20 metres away from thereceiver.
Reference
1. The additional LUTs for Satsignal can be downloaded from:www.satsignal.net
by opening the ‘Satellite Tools’ page, clicking ‘Satsignal’ thenclicking the ‘Colour look-up table’ link under ‘Downloads’.

Figure 1 - Image processed using the normal ‘HLS’ LUT

Although the HLS image above shows the heavy cloud inthe area, the cloud-top LUT shows the extent of therainfall. As in the BBC weather maps, the brighter thecolours the heavier the rain (yellow, red, purple, white).
The lowest cloud-top temperatures are shown as white.

Figure 3
This scene comes from the HRPT version of the same NOAA-12 pass
Image: David Taylor - Processing Satsignal (vegetation mode)

www.geo-web.org.uk

9

GEO Quarterly No 5

Group for Earth Observation

March 2005

NASA/USGS

Mount St Helens is undoubtedly the best known of North
America’s Cascade Range volcanos, following the historic 1980
eruption which devastated over 200 square miles of forest. The
mountain rumbled back into life in late September 2004 as a
new lava dome began to rise from its crater and on October 1 a
spectacular cloud of ash and steam erupted from the mountain
as illustrated in the photographs opposite.
Scientists from NASA and the United States Geological Survey(USGS) have joined forces to study Mount St Helens using ahigh-tech laser scanning technique known as LIDAR. This
analyses changes in the surface elevation of the crater, whichbegan deforming in late September 2004. The data derived from
LIDAR enables the scientists to make accurate comparisons of
the topography before and after a volcanic event and to map thethe dimensions of any uplift—often in exquisite detail—and thus
create better models for forecasting future volcanic events.

Figure 1 -Mount St Helens October 1 eruption plume
photographed from Johnston Ridge Observatory
Photo: Gene Iwatsubo, USGS

What is LIDAR?
Airborne LIDAR was pioneered by NASA scientists andengineers during the 1980s and 1990s. LIDAR can be used tocreate digital elevation models and, because of its very highvertical accuracy (as good as 10 cm), it is rapidly becoming thepreferred method for detailed topographic mapping.
LIDAR (Light Detection and Ranging) is a remote sensing
system, technologically very similar to RADAR (Radio Detection
and Ranging), that can be used to collect topographic data. The
key difference in LIDAR is that light rays are used instead ofradio waves. The LIDAR equipment is carried aboard a lightaircraft such as a Cessna-310 and comprises a scanning laser
rangefinder, a Global Positioning System (GPS), and an Inertial
Navigation System (INS).
During its flight above the terrain to be mapped, the aircraft
travels at approximately 60 meters per second while the LIDAR
instrument pulses a narrow laser beam toward the Earththrough a port in the underside of the plane's fuselage. LIDAR
lasers generally operate in the near-infrared so that the radiation
reaching the ground will not cause eye damage to any humans
who are in the target area as the plane flies overhead. The laser
directs up to 5000 brief pulses of radiation per second towards
the ground which reflects or scatters them back to the laser
scanner (figure 3).

Figure 2 - Mount St Helens erupting on October 1, with renewed
activity within the mountain’s old 1980 eruption crater.
Credit: John Pallister, USGS

Data are collected by measuring the distance between the plane
and the Earth beneath by accurately timing how long it takes foreach reflected pulse to return to the plane. These reflected
pulses are received through a small telescope which focusesthem on to a detector. The time intervals are then used to
calculate a set of distance values over the flight corridor.
The distance measurements obtained from each laser pulse areconverted into map coordinates and elevations by combining
them with information about the position of the plane (from theGPS) and the direction of the laser pulse (from the orientation of
the plane as determined by the INS) at the precise instant thateach pulse was fired. A large area can be mapped by flying
10

www.geo-web.org.uk

Figure 3 - Airborne LIDAR scanningMarch 2005

Figure 4 -Group for Earth Observation

GEO Quarterly No 5

This stunning image of Mount St Helens was produced by draping a 1-km/pixel IKONOS satellite image over an elevation map
created from the October 4, 2004 aerial LIDAR survey. The new lava dome can clearly be seen rising behind the old one thatformed between 1980 and 1986. To its right, a dark slit shows where a new vent opened as the volcano erupted.
Credits: IKONOS imagery provided courtesy of Space Imaging - LIDAR derived elevation map courtesy of USGS and NASA.

many parallel lines, guided by the GPS, so that successive
narrow corridors of data overlap along the edges. The data fromall the corridors is then assembled to provide coverage over alarge area.
The Mount St Helens Survey

References
http://vulcan.wr.usgs.gov/Monitoring/LIDAR/
http://www.ghcc.msfc.nasa.gov/sparcle/sparcle_tutorial.html
http://www.sbgmaps.com/lidar.htm
http://earthobservatory.nasa.gov/Study/Lidar/

The USGS first contracted a LIDAR survey of Mount St Helens
in September 2003. In early September 2004, USGS and NASAscientists began detailed planning for a second survey,
contracted by NASA, which would extend the area covered by
the first survey. But when the mountain came back to life on
September 23, these plans were fast-tracked, and the second
survey was brought forward to October 4. Topographic changes
resulting from the current activity at Mount St Helens are clearly
evident in figures 5 and 6 below).
The results from the October 4 survey are shown in figure 4,
where a one-meter-per-pixel image from Spaceimaging’s
IKONOS satellite has been draped over the LIDAR elevation
map for the area. The new lava dome rises behind the old onethat formed between 1980 and 1986. LIDAR determinations
showed that in the two weeks prior to the October 4 eruption,
the new dome rose 110 meters—roughly the height of a 35
storey building—and covered an area of 130,000 square
meters, equivalent to 5.3 million cubic meters of volume change
in the area of uplift. To the right of the uplift a dark slit showswhere a new vent opened as the volcano erupted.
And the dome wasn’t the only change that the LIDAR data
recorded. Unrelated to the eruption, rock glaciers were seen tohave moved downslope as new material fed into them. One
such glacier can be seen on the left edge of figure 4. A
comparison between this year’s topographic map and lastyear’s shows shrinking snow fields, growth in the crater glacier,and several rock slides.

Figure 5 - LIDAR images (2003, left and 2004 right). The recent
uplift is clearly visible in the right-hand image.
Photo: NASA/USGS

Figure 6 - Close-up LIDAR images (2003, left and 2004 right) clearlyShowing the new lava dome in the right-hand image.

www.geo-web.org.uk

Photo: NASA/USGS

11

GEO Quarterly No 5

The 11:22 UT NOAA-17 HRPT image
from September 8, 2004 pictured above
was sent to GEO by Mike Jupp who
commented: ‘What a clear day—virtually the whole of the UK is cloud
free—makes a change.’ The image wasprocessed using David Taylor’s HRPT
Reader software, using channels 3, 2
and 1 as the red, green and blue
channels respectively.
The APT image segment at right was
12Group for Earth Observation

provided by Gerry Berg (DK1RR) from
Germany, who spotted an interesting
wake of Von Kármán vortices south of
Jan Mayen Island in the North Atlantic
on September 23, 2004. The pass camefrom NOAA-12 at 16:04 UT on that day.
On the back cover of this Quarterly you
will find the same vortex street as
imaged by NASA’s Terra satellite using
its maximum ground resolution of 250
metres per pixel.
www.geo-web.org.uk

March 2005

March 2005

Group for Earth Observation

GEO Quarterly No 5

Rob Hollander, Harrie van Deursen and Ruud Jansen
Our preliminary results on antenna measurements were
presented in GEO Q3 in our article 'Antenna Theory andMeasurement, part 1' and more results had been promised
for part 2. However, the measurements on gain, radiation
pattern and cross polarisation that we have completed so
far revealed a fundamental problem with antenna
measurements, one we had completely underestimated.
We feel that we have to solve this problem first, or find away to reduce its influence on the results, before part 2
can be launched.
In this article we describe the problem, one that is present
not only in antenna measurements but also in any
practical antenna geometry. It may well be that
'unexpected antenna performance' becomes less mysterious after reading this article. You may even findreasons to change your antenna position to get better
satellite reception. After all, antenna performance underreceiving conditions is what counts; antenna
measurements are only interesting for those freaks whowant to know whether their strange constructions (i.e.
antennas) perform as expected or not.
The problem has nothing to do with poorly constructed
antennas, measurement equipment, data-analysis oreven with the skills of the person performing themeasurements: it stems from the simple fact thatelectromagnetic waves are reflected from every interface
between media with different dielectric properties, e.g.
'ground', walls, trees etc. Wave reflections are specular (asfrom a mirror) when the surface is flat but are more orless 'scattered' from rough surfaces. Moreover, waves'bend' around edges (are 'diffracted'). This means that thewaves that fall on to our antenna don't necessarily comestraight from the satellite you want to receive or from thetransmitting antenna during an antenna measurement.
The geometry around transmitting and receiving
antennas determines the reflections: how strong they are
and from which direction they arrive. Also, due to thedifference in path-length between the direct and thereflected waves, the phases of both waves are different.
Moreover, the amplitude and phase of a wave change onreflection and these changes depend on the polarisation of
the wave relative to the plane of incidence, on the angle ofincidence and on the 'ground'-conditions (conductivity anddielectric constant). These are illustrated in figure 1.
Ultimately, all these waves interfere—combine, taking
into account the direction, amplitude and phase—to
produce the antenna signal.
The combination of direct and reflected waves may resultin a much larger signal than from the direct waves only
(constructive interference) or the two waves may evencompletely cancel each other (destructive interference),
depending on their relative phases. This latter effect isthe reason for 'noise bands' in images from satellites near
the horizon where, in each band, the direct and reflected
waves are about equal in amplitude but 180 degrees out

Figure 1
Waves from vertical antennas have their E-vector in the plane ofincidence, formed by the incoming wave vector I and the normal N to thehorizontal surface S shown on the left. After reflection the reflected wave
R seems to come from the mirror antenna M. In case of a perfect(conducting) ground the phase does NOT change at reflection.
Waves from horizontal antennas have their E-vector perpendicular tothe plane of incidence as is shown at the right. In case of a perfectground the phase changes 180 degrees at reflection, since the total Efield from the antenna and its image at the conducting ground plane
should be zero.

of phase. The path difference between consecutive bands
is just one wavelength! This effect is clearly visible inimages that are received with an antenna that is linearlypolarised at the horizon (like a turnstile antenna).
The 180° change in phase on reflection in only one of thetwo polarisation directions also means that circularly
polarised waves change their sense of rotation onreflection; LCP becomes RCP and vice versa. If ourantenna is circularly polarised at the horizon, e.g. RCP,
we receive the direct waves which are RCP, but do not see
the reflected waves which are LCP. Now we cannot get
destructive interference! If our antenna, like the RQHA,
is only 70% RCP (and 30% LCP) at the horizon, then somedestructive interference will occur, but complete
cancellation will not. Usually there is enough signal
strength left to obtain a noise free image.
As soon as we realised what the cause of the strange
results in our measurements was, we found many bookswith descriptions of the phenomenon [ARRL Antenna
Book-20 with practical information, Jackson p.278 for
EM-fields, and Schelkunoff p.201 on antenna theory].
We felt as if we had just reinvented the wheel!
In the ARRL Antenna Book (edition 20) you can findsuggestions for antenna measurement set-ups. Some setups are rather good for antennas with a high directivity,
like Yagis and parabolic antennas, because with suchantennas it is often possible to arrange the geometry suchthat the reflections come from a direction in which thewww.geo-web.org.uk

13

GEO Quarterly No 5

Group for Earth Observation

AUT (antenna under test) is essentially 'blind'. For omnidirectional antennas like the RQHA or the turnstile
antenna there are virtually no such prospects. In fact only
two set-ups can be used: one in free space; the other a setup in a reflection-free measurement room. For the first we
had thought of using helium balloons. For the second weare still looking for an organisation that has a reflectionfree room large enough for measurements at 137 MHz
and who are willing to let us use that expensive facility forfree. Good measuring conditions for 1.7 GHz are much
more easily obtained since transmitter and receiver canbe as close as 1 metre to each other to be in the far fieldregion. It is easy to make a set-up with reflecting objects
much farther away than this 1-meter separation.
It is fairly simple to measure, yourself, how serious
reflections are, using just a transmitting dipole and a
receiving dipole. For our measurements we used 'current'
baluns comprising five large ferrite beads, resulting in an
impedance of more than 1 kΩ for the outside of the copper
braid to keep it free of radiating currents. Moreover, weused an impedance transformation from 61 Ω for our
dipoles, nicely at resonance at 137.5 MHz, to the 50 Ω ofour measuring system with two pieces of co-ax cable of93 Ω and 75 Ω. For this first simple test the impedance
transformation is not necessary, but we did so for our gain
comparison with other antennas later on. You should
realise that at the end we want to compare how different
antennas behave in the same EM field. What we measureis the signal voltage. However, the electric field produces
a current in our antenna proportional to the field strengthand this current produces the signal voltage across theantenna impedance.
To avoid reflections in the cables we have to transform theantenna impedance to the input impedance of ourmeasuring system, typically 50 Ω. Moreover, after
transformation, we can use the signal voltages obtainedwith different antennas in gain comparisons. The baluns
are necessary, otherwise you do not see only your dipoles
transmitting, but the cable as well. For this test it is
crucial that we make a pure dipole field in one
polarisation only and measure this polarisation alone. We
found that our measurements were almost free of cable
geometry (the effect is much less than 1 dB).
The transmitter used for both the rotating dipole andreflection test measurements was a small battery
operated oscillator, tuned at 137.5 MHz and fitted with again control, whose output level was continuously
adjustable by means of a potentiometer. The feed cable
was 50 cm of RG-174 running several times through along ferrite bead. Both transmitter and balun are very
compact and were placed directly at the antenna
terminals.
The transmitting and receiving dipole antennas were
mounted on poles about 3 m tall and some distance apart(use non-metallic pipe such as plastic drainpipe) and the
137 MHz output level was adjusted so that it did not
overload the receiver. The signal strength was measured
when both antennas were horizontal and again when bothwere vertical. If there are no reflections both measured
signals should be equal whatever the distance between
the antennas. If there are reflections the vertical set-up
will usually give a lower signal then the horizontal one(Table I).
14

March 2005

Antenna distance(m)
2
10
1 3 .1
1 7 .5~ 150

H-H minus V-V H-H
(dB)
(dB)
1 .5
7 5 .53 .2
6 5 .2
3 .0
64.3
2 .8
6 1 .54 .3
4 2 .0H-H
cor r ected
8 0 .66 6 .664.3
6 1 .84 3 .1V-V(dB)
7 4 .06 2 .061.3
5 8 .73 7 .7

V-V
cor r ected
7 7 .6
6 3 .661.3
5 8 .84 0 .1

Table I - using a 13.1 m reference distanceIn table I, columns H-H and V-V are the measured
signals; columns H-H (corrected) and V-V (corrected) are
the values that should have been measured assuming themeasured values at 13.1 m and at the other distances
corrected for the distance effect of 1/r (valid in the far
field approximation). It is clear that the 1/r law applies
for distances over 10 metres rather well.
The difference between H-H and V-V depends not only on
the distance between the antennas but also on the heightsof the mounting poles. The reflection coefficient of theground and the phase-difference between the direct andreflected waves determine the measured signals at agiven distance. We measured that, with a certain
combination of distance and height, the difference H-H
minus V-V was almost 6 dB!
To test the cross polarisation, we measured the
combination H-V at a distance of 10 metres (H represents
the transmitting dipole, V the receiving dipole). The
signal is now -30 dB relative to the combination H-H at
the same distance, indicating that the polarisation of the
field is quite pure (i.e. no V-contribution from the verticalcable!).
What will happen when we replace our receiving dipolewith an RQHA? When we place the RQHA with its axis
towards the transmitter, then we expect that the received
signal will be independent of the rotation angle aroundthe axis. This has to be so, since the radiation pattern forhorizontally as well as vertically polarised fields is axiallysymmetric. Moreover, the RQHA is circularly polarised,
and thus signals from the H-field should be as strong as
those from the V-field, provided that the H-field itself is asstrong as the V-field. Since we have already seen with our
dipole-dipole measurements that this is not the case, we
can expect that the signal from a V-field will be smaller
than that from an H-field. We tested this for threeantenna distances (table II).
Antenna distance H minus V H-tr ansmit
(m)
(dB)
(dB)
3 .4
1 .1
7 3 .1
1 7 .4
3 .8
61.0
~ 150
3 .6
4 2 .0H-tr ansmit
cor r ected
7 5 .261.0
4 2 .3

V-tr ansmit(dB)
7 2 .057.2
3 7 .4

V-tr ansmit
cor r ected
7 1 .457.2
3 8 .5

Table II - using a 17.4 m reference distance

The meanings of the columns are the same as in table I,
except that the reference distance for the correction is17.4 m. Rotation of the RQHA around its axis resulted ina variation of only ±0.1 dB, which is about themeasurement error.
The conclusion is that the fields from horizontal andvertical dipoles are pure H- and V-polarised fields
respectively. The H-field and the V-field are not the same
in total strength, mean direction and total phase due todifferent reflection properties of the two components.

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March 2005

Group for Earth Observation

Using a rotating dipole to measure the H-polarised and Vpolarised radiation patterns in a single measurement
introduces a complication. At first there is a modulation of
the measured signal with twice the dipole rotation
frequency. This modulation is also present when thereceiving antenna is equally sensitive to an H- and a Vfield, which should be the case for a circularly polarised
antenna (apart from the phase relation). It is possible tomeasure first the difference in the produced fields with adipole antenna then correct the measured H- and Vsignals of the AUT. This is possible in a static
measurement where you know the orientation of thetransmitting antenna. With a rotating dipole you shouldmeasure the rotation angle at the same moment as thesignal and the AZ- and EL-angles of the AUT. Correcting
the measured H- and V- modulated radiation patternobtained in a rotating dipole set-up, assuming that thelarger signals come from the H-field and the smaller fromthe V-field, is tricky; you do not have that information.
This is the complication I mentioned earlier!
You can assume that your AUT, like the RQHA pointing
with its axis towards the transmitter, is equally sensitive
to an H- and a V-field or measure the modulation of thesignal of the AUT. For an RQHA with its axis pointing
towards the transmitter this modulation should be thesame as the difference in signal between the H- and Vfields from a static transmitting dipole, since we hadalready measured that the RQHA was equally sensitive toan H-field or a V-field independent of its rotation angle
around its axis. Assuming that the outer envelope of themodulated pattern represents the H-field and the inner
the V-field for all EL-angles may result in incorrect
results since both patterns may cross at some EL-angle.

GEO Quarterly No 5

limit for the cross-polarisation that can be measured. You
do not know which part of the measured crosspolarisation comes from the sensitivity of your antenna to
the incorrect polarisation or from the field containing theincorrect polarisation. Reflections contribute up to 50% in
the final field.
Conclusions
It should be clear that, in antenna measurements,
reflections should be avoided. In relative gain
measurements, where the signal of an AUT is comparedwith the signal of a reference antenna, reflections enter
into the result because the radiation patterns of AUT andreference antenna are not the same. The signal results inboth cases from the same field, but the weighting of thereflections is different. Usually this is a small effect.
We already saw that the measurement of radiation
patterns is fully influenced by reflections; we simply don't
know where the reflected waves come from or, in otherwords, what angle of the pattern should be assigned to themeasured signal strength? In radiation patternmeasurements with circular polarisation, we also don't
know what the degree of polarisation mixing we arelooking at is—in other words, what pattern are wemeasuring: RCP or LCP? Measuring a horizontally
polarised and a vertically polarised radiation patternseparately (in two static dipole measurements or in one
rotating dipole measurement) is not the same as aradiation pattern measurement with a circularly
polarised field. There is no information about the relative
phase of the horizontally and vertically polarised
components. If, as in the ideal case, the patterns (and thesignal strengths) are identical, then circular polarisationis possible but linear polarisation cannot be ruled out.
Cross-polarisation measurements are impossible in thepresence of reflections. If we want to measure a -20 dB
cross-polarisation (or even less) the field should be muchpurer than that 20 dB. The problem is not that we cannot
produce such a field with a good transmitting antenna(although this is not trivial), but that the field is not pureat the time when the reflections show up. It seems that
this type of measurement can only be performed at a large
reflection-free EM-test facility, which is far beyond thescope of amateurs.

Figure 2 -The team making measurements. From left toright: Arne van Belle, Rob Hollander and Harrie vanDeursen. At the right is an interested passer-by.
Photo: Ruud Jansen

Measurements with circular fields are even more
complicated. Due to the reflections, where RCP becomes
LCP and vice versa, it is not possible to measure the RCPand the LCP-radiation patterns separately. If we startwith a pure RCP-field then the direct wave will have thecorrect polarisation and the expected direction. The
reflected wave has the wrong polarisation and comes fromsome unknown direction. How should the single signal,
the result of both the direct and reflected fields, beinterpreted? The RQHA is not 100% RCP at all angles! In
fact, this percentage is what we want to measure! Things
mix up and cannot be disentangled.
Cross-polarisation measurements with circular fields
require very pure RCP- and LCP-fields. Mixing ofpolarisation, e.g. due to reflections, immediately sets the

Our preliminary results already show that, despite theproblems with reflections, it is possible to obtain radiation
patterns that are not far from the expected ones. This
gives hope for gain measurements as well. We still hopethat we can find a geometry in which gain and patternmeasurements can be performed with good accuracy. We
have to test that geometry for reflections. Until now, we
can only conclude that high mounting poles (10 m ormore) and a small antenna distance (~10 m) arefavourable. We have thought of using metal fences toscreen ground reflections when the distance between
transmitter and AUT is relatively large. This idea can be
combined with a location where we can place thetransmitter and the AUT on two hills in such a way thatthe surface where the reflections are produced is not
visible from the AUT. We have already tried this (without
fences) but the results were disappointing. We have torepeat these measurements now knowing better where to
look. If nothing else helps, we may try a balloon
experiment.

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15

GEO Quarterly No 5

Group for Earth Observation

March 2005

Clive Finnis
If all goes according to plan, a new NOAA weather satellite
should start transmitting APT and HRPT imagery of the Earththis month. NOAA-N, the last-but-one satellite in the current
Polar Operational Environmental Satellite (POES) series waslisted for a March 19 launch and, once it reaches orbit, it will berenamed NOAA-18. Just one more NOAA satellite remains to belaunched, the ill-fated NOAA-N prime, which is currently
undergoing repair at the Lockheed Martin facility in California(see GEO Q3, page19). Subject to successful restoration, thisfinal APT-carrying satellite will launch in December 2007.
Looking to the future, the new all-digital National Polar-orbiting
Operational Environmental Satellite System (POESS) kicks off
in 2009. A feature of the new system is a change in thetransmission frequencies: the familiar 137.50 MHz and137.62 MHz will be no more. Two entirely new frequencies in
the 137-138 MHz band have been allocated, and these will also
be used with the final two NOAAs.
Consequently, unless you possess a tunable weather
satellite receiver, you will not be able to receive APTtransmissions from NOAA-N and NOAA-N-prime!
But there is good news for the hundreds of APT enthusiasts who
use the ubiquitous RX2 receiver, designed by Ray Godden, to
receive their images. The RX2 has given great service for many
years but it cannot currently tune in to the new frequencies of137.1 MHz and 137.925 MHz.The required frequencies in theRX2 are generated by means of control signals from themicrocontroller PIC (IC6) to the frequency synthesiser TSA6057(IC4). The solution to this problem is to provide a new PIC
microcontoller which has been re-programmed to provide these
new frequencies.

Thus channels 2, 3 and 4 will remain the same as the old PIC.
Channels 1 and 5, which used to hold the 137.30 MHz and137.85 MHz frequencies used by the Russian Meteor series of
APT satellites have been re-allocated: as far as is known, thesefrequencies will not be used again.
Channel ’t’ the test channel, selected by holding down the front
panel push button at power-up, remains as before at
137.970 MHz.
When in scan mode, the new PIC will scan channels 1 to 5
inclusive, as on the original device.
The new PIC also incorporates the code developed by Max
Hadley for remote control of the RX2 from a PC serial port. See
photographs of the PIC and RX2 inside the back cover.
Installing the GEO-PIC
Fitting the new PIC is easy. It is the only IC in the RX2 that isfitted into a socket: so the old one can be carefully prices fromthe socket using a small jeweller’s screwdriver. Be sure toobserve anti-static precautions, as the new PIC, like mostmodern electronic components, can be damaged by a static
electric discharge. The easiest precaution (if you do not havethe conductive wrist bands used by professionals) is to touch anearthed object such as a metal radiator immediately prior to
removing the new PIC from its protective black conductive foam.
However do not worry if you are unsure of what to do—fullinstallation and operating instructions are included.
Check your Synthesiser Chip
Early RX2s were fitted with a different synthesiser chip in
position IC4 (a TSA6060) and this requires different code in the
PIC to ‘drive’ it correctly. Do check this out. If your RX2 has thischip fitted please tell us when you order so that we can ensurethat you receive the correct PIC for your receiver.
If you do not mention this we will automaticallyassume you have the TSA6057 and send you a PIC tosuit (the TSA6057 is fitted to the majority of RX2s).

This PIC, called the GEO-PIC version 1.0, isavailable from the GEO Shop (see page 46) andwill provide the following frequencies.
• Channel 1• Channel 2• Channel 3• Channel 4• Channel 5

Note:

16

-

137.100 MHz
137.400 MHz
137.500 MHz
137.620 MHz
137.910 MHz(new for NOAA-N)(Okean/Sich)(NOAA 12, 15)(NOAA 17)
(new for NOAA-N)

What does this new PIC Cost?
For members residing in the UK the price is £7.00. The cost formembers in continental Europe is £7.60 and for the Rest of theWorld it is £8.00. All these prices include carriage and packing.
We will ship by post, so please allow a few days for the PIC toarrive in Europe and perhaps a few weeks for the Rest of theWorld.
Items from the GEO shop are available
only to paid up GEO members.

137.91 MHz is as close as it is possible
to program the RX2 to 137.9125 MHz

www.geo-web.org.uk

March 2005

Group for Earth Observation

GEO Quarterly No 5

Thailand Tsunami Damage - December 29, 2004 .. the Greatest Human Disaster in Living Memory
The beaches of Khao Lak, Thailand were struck by a tsunami 2-3 hours after a magnitude 9.0 Indian Ocean earthquake on December 26. Althoughsome 500 kilometres distant from the epicentre, the waves were 10 meters high. The top image shows a coastline area popular with European tourists
as it was on January 3, 2003. The lower image shows buildings and vegetation scoured by the tsunami, leaving only foundations and bare soil. Vastquantities of beach sand were also washed away. These high-resolution satellite images were acquired by Space Imaging’s Ikonos satellite.
Images: © Space Imaging.

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17

GEO Quarterly No 5

Group for Earth Observation

March 2005

Les Hamilton

We know from comments we receivefrom GEO readers just how much you
appreciate the high-resolution (HRPT)
images from the American NOAA
satellites. These can of course beacquired directly from the satellites
themselves by anyone prepared tomake the necessary outlay for a
dedicated receiver and tracking
antenna—but there is an easier way.
The same raw HRPT data files
transmitted by the NOAA satellites areavailable on the Internet and can be
downloaded free from a number ofsources, most notably from NOAA’s
own Satellite Active Archive (SAA). If
you cannot afford to purchase acommercial HRPT system and lack theexpertise to build your own from a kit
this provides an alternative means ofaccessing the fascinating world ofhigh-resolution satellite imagery.
Registering with SAA
Although you must first register with
SAA before they will permit you to
download their products, this is just aformality—and there is no charge. Just
direct your Internet browser to;
http://www.saa.noaa.gov

and click the ‘Register’ link at the top
right-hand corner of the screen. The
only information you have to supply
are your first name, last name, e-mailaddress and password. The password
is of your own choosing, and isrequired when you log-in to the site.
Logging-in
Once registered, you can log-in to the
SAA site and select files for download.
Do this by clicking on the ‘Login’ link at
the upper right-hand corner of the
opening screen.
Type your first name into the‘Username’ field and your chosenpassword into the ‘Password’ field.
(figure 1) then click OK. Wait a few
seconds until the screen refreshes (the‘Login’ link will now have disappeared)
and open the ‘Please select a productto search’ window, part of which isshown in figure 2. Click on the first itemin the list, ‘Advanced Very High
Resolution Radiometer’, then on thelink labelled ‘Go’. You are now taken to
the page where you can select the typeof image you wish to search for, aspecific satellite, and the start and end
dates for your search. The relevant
part of this page is shown in figure 3.
Available Data Types
There are three types of data that you
can select. The uppermost item, GAC,
provides global coverage fromsatellites at a similar resolution to thefamiliar 137 MHz APT. These files
produce images with a maximum
ground resolution of just four
kilometres per pixel. You are almost
certain to be able to locate an image
from anywhere on the planet in this fileformat. HRPT provides the fullresolution 1-km/pixel raw data stream
received live from the satellites atground stations in the USA, ideal if you
require images of North America andthe Caribbean. LAC also provides the
HRPT data stream, but these files arerecorded aboard the satellites whilst
flying over regions out of direct rangeof US ground stations; the data arerelayed to Earth during a subsequent
orbit.

Figure 1 - The Login window

Figure 2 - Selecting NOAA data

If you require HRPT data files for
Europe, Asia or Australasia, then you
should check the box beside LAC.
Because of the recovery method forthese data, you may often have to wait
till the following day before LAC files
become available for downloading.
Selecting a Dataset
The options for Receiving Station andDistribution Site can safely be left
untouched at their default settings. The
Node options afford the opportunity ofrestricting your search to ascending ordescending satellite passes: leaving all
options unchecked has the same effectas checking the ‘either’ option. Should
you wish to restrict your search to just
one specific Satellite, click on its nameto highlight it—otherwise passes for all
satellites will be searched for anddisplayed.

Figure 3 - Selecting a Dataset

Figure 4 - Selecting a date from the calendar

18

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March 2005

The Temporal setting allows you torefine the search interval (one weekprior to the current date by default).
Either or both of two interactive
calendars above the map at the foot of
the page may be modified to increase
the breadth of search, or to restrict it toa single day (figure 4). You can also
restrict the hours searched by entering
Start Time and End Time in the fields
provided. Finally, you must define
Spatial details for the area over which
you wish to search for satellite data by
dragging a rectangle over the map tooutline the target region. You can zoom
in for increased accuracy (figure 5).
User Preferences
The menu in the left-hand margin ofeach page contains the option ‘User
Preferences’. It is here that you canchoose which of the five HRPT
channels you require for the various
file formats. Do this prior to ordering
your first datafile from SAA. Be certainthat you select 10 bits/pixel for each(figure 6). These preferences remain inforce for future downloads until suchtime as you decide to change them.
Ordering Datasets
Once all the above has been
completed, click on the Search button
beneath the map and await a listing of
all the appropriate satellite passes(figure 7). If you are searching over an
extended time interval this may take alittle time and present you with a large
number of datasets in a paged list.
Generally, it is helpful to restrict the
search to a specified 24-hour period.
You can view thumbnails of any image
by clicking the button in the
View Details column at the left of eachline in the table (figure 8).
If you are happy with the image, returnto the Search results screen, checkthe box in the Shopping cart column
then click the Go to cart button at the
top of the page. This takes you to the
Shopping cart screen (figure 9) where
all that remains to be done is to click
the Place order button at upper left.
Note: the ‘Include Archive Header’ box
is always checked by default - do notalter this.
You should receive confirmation ofyour order almost immediately, and an
e-mail (to the address you provided
when you registered) confirming this isalso sent out shortly thereafter.
The datasets that you order are placedin a folder on the SAA FTP server for
you to download. There will be a delay

Group for Earth Observation

while this is set up for you, but you
should receive a second e-mailconfirming the address; this often
arrives within minutes though it cantake several hours during busy
periods. Note, however, that if you
request data that is more than a week
old, it may sometimes be several days
before it is made available for you.
HRPT datasets can be large (some areof the order of 100 Mb). In general, a
10° spread in latitude equates to 16 Mbof data. As image processing can takea considerable time, particularly on low
specification computers, it doesn’t pay
to order a file larger than you require!
The whole point of HRPT, surely, is toinvestigate small regions in high detail.
Additionally, if you are using a dial-up
Internet connection, it again pays toorder the smallest datafile that suits
your needs, as even a 16 Mb file as
noted above will take the best part ofan hour to download. You can reduce
file size by ordering only channels 2+4
if all your interest is in producing falsecolour images.

GEO Quarterly No 5

Figure 5 - Selecting the area (zoomed)

Figure 6 - User preferences

If you plan to download HRPT
telemetry files on a regular basis, you
should seriously consider switching toa broadband Internet account.
Once you receive notification that yourfile is available for download you havejust 72 hours to retrieve it before it iscleared. You can retrieve your file withan ftp program of your choice or via
your web browser. Note that when
downloading via ftp you must select a‘binary’ (or ‘image’) mode of transfer,not ‘text’ or ‘ascii’.

Figure 7 - Search results

HRPT Imaging Software
Once you have downloaded an HRPTor LAC datafile you have to process it
into images. The software preferred by
the majority of enthusiasts is the HRPT
Reader Program [1] written by David
Taylor. This program can be obtainedin both free and registered versions.
The free version is perfectly adequate
for getting started but a number ofmore sophisticated image processing
options are available upon registration.
If you have not run any of David’s
software before, you will also require to
install the Runtime Library Bundle.
HRPT Reader comes as a ZIP file. As
it does not have an installer you must
create a folder on your hard drive
called ‘HRPT Reader’ and unzip all thecontents into this. It is also advisable tocreate two sub-folders within it, RAW
and IMAGES, the former to store yourwww.geo-web.org.uk

Figure 8 - Dataset details

Figure 9 - Shopping cart

19

GEO Quarterly No 5

Group for Earth Observation

This splendid NOAA-16, false-colour image was preparedfrom an SAA ‘HRP’ datafile dating from 21:40 UT on June 28,
2003. The image displays a cluster of fascinating ‘ship
tracks’ over the Pacific Ocean. Vancouver Island and theThis scene was observed by NOAA-17 at 03:11 UT on
June 12, 2003. The raw datafile was acquired from
Russia’s SMIS server. The centre of the image is

20

March 2005

snow-capped Coast Range are prominent, as are theColumbia and Snake Rivers. The volcanic peaks of the
Cascade Range stand out like a regiment of white beacons.
Telemetry data: NOAA SAA Processing: HRPT Reader

dominated by the Caucuses Mountains stretching
between the southern Caspian Sea and the Black Sea.
Telemetry data: SMIS Processing: HRPT Reader

www.geo-web.org.uk

An armada of Icebergs courses southward along theeast coast of Greenland in this channel-2 NOAA-17
segment dating from June 14, 2003.
Telemetry data: NOAA SAA Processing: HRPT Reader

GEO Quarterly No 5

Group for Earth Observation

downloaded datafiles, the latter to hold the images you prepare
from them.
Creating HRPT Images
The files from SAA have meaningless automatically generated
filenames: for example ‘A4416181.L5629091’. This can be readby HRPT Reader, but it is best to edit the extension to ‘GAC’,‘HRP’ or ‘LAC’ to give a filename like ‘A4416181.HRP’. The
stem of the filename can also be changed to a more meaningful
name if you wish. Using these extensions ensures that the
decoding software ‘understands’ the architecture of eachspecific datafile, and interprets it correctly.
Use the <File → Open> menu to navigate to your RAW folder
and double-click on an HRPT datafile. If you have a relatively
high-specification computer, HRPT Reader should display theimage after just a few seconds. Figure 11 compares processing
times for a variety of PCs, using raw datafiles of two different
sizes. Although a faster processor bring benefits, the key tospeed is having lots of RAM. As the table indicates, you canprocess small HRPT datafiles with as little as 32 Mb RAM—but
it takes a long time: in the case of the 31 Mb test file, thePentium-1 PC took a further three minutes just to write theimage to the screen once initial processing had been
completed!

March 2005

<Options → Results location> from the menu-bar to navigate tothis folder then click on it. Now any file saved using the options
under the <File> menu will be placed in that folder. The
particular image saved is always the one actually displaying at
the time of the save; if you save while the false-colour image isdisplayed on the screen, it is that false-colour image that will besaved, and so on.
Images can be stored in a variety of formats. <File → Savedisplayed image> saves the geometrically uncorrected HRPT
image (exactly as it appears on screen) in lossless BMP format
at 1.1 km/pixel resolution. The <File → Save with correction>
option applies geometric correction to counteract perspective
effects caused by Earth’s curvature, which occur at the edges of
the images. <File → Save as APT> produces a corrected but
subsampled version of the latter, with a resolution of 4-km/pixel.
There are also options to save in the compressed JPEG format.
Other Sources for HRPT Files
HRPT data from the NOAA satellites is downloaded daily by theSpace Monitoring Information Support Laboratory (SMIS) in
Moscow, Russia [2]. There is a wealth of material available onthe ‘Satellite Data Page’ [3]. The link ‘Telemetry Active Archive’
allows you to download datafiles collected during the previous
28 days and files for the previous 24 hours are available fromthe ‘Last telemetry files’ link. HRPT files are also available fromthe ZS RCPOD, Novosibirsk server [4]. This has the advantageof access to NOAA passes farther east than Moscow.
References
1. HRPT Reader is available from Software Showcase. You
can also download it yourself fromhttp://www.satsignal.net on David Taylor’s website. You
will find the link to HRPT Reader under the ‘Satellite
Tools’ section. The link to the runtime library bundle is on
the HRPT Reader page under the section headed‘System Requirements’.
2 SMIS
http://smis.iki.rssi.ru (or http://d902.iki.rssi.ru)
3 SMIS Satellite Data Page
http://smis.iki.rssi.ru/dataserv/engl/data_s_e.htm
4 ZS RCPOD, Novosibirsk
http://212.17.0.65/tlm_cat/tlm_cat_e.sht

Figure 10

HRPT Reader screen displaying overnight snowfall in
the Low Countries - NOAA 17, February 29, 2004

Pentium I

Speed
(MHz)
233

RAM
(Mb)
32

Processing(32 Mb file)
7 min 20 sec

Processing(64 Mb file)-

Pentium II

366

192

18 sec70 secProcessor

Pentium III

500

256

12 sec47 secPentium IV

2800

1000

3 sec

7 sec

Figure 11 - Processing times on various PCs

The images from all five of the HRPT channels are available forinspection simply by clicking the appropriate channel tab at the
top of the screen (figure 10). A number of specialised images
produced by combining these channels in various ways can also
be viewed on the other tabs (False colour, RGB, Sea surface
temperature etc), but a detailed description of these is beyond
the scope of this article.
Saving Images
Before saving an image for the first time it is necessary to ‘tell’
HRPT Reader the location of your ‘IMAGES’ folder. Select22

A channel-2 NOAA-17 HRPT segment from February 29, 2004, whenmuch of Scotland and northern England were blanketed in snow.

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March 2005

Group for Earth Observation

GEO Quarterly No 5

Peter Wakelin
TRMM Mission Extended Again
Launched in 1997, the Tropical Rainfall Measuring Mission
spacecraft was designed to operate as a three-year research
mission. After four years of extending TRMM, which is now low
enough to experience significant atmospheric drag, NASA andits mission partner, JAXA (Japan Aerospace Exploration Agency)
planned to decommission TRMM and proceed with a safe,
controlled deorbit.
However, in view of the high value of the data being returned, forboth research and use in operational weather forecasting, theNational Academy of Science’s Committee on the future of
TRMM ‘strongly recommended continued operation of TRMM, atleast until such a time as a decision on controlled reentry
becomes unavoidable.’ Destined to end up as a charred wreckon the floor of the Pacific Ocean, TRMM has been granted a few
months’ reprieve.

Another recent development is the selection by NASA, on
NOAA’s behalf, of contractors to work on aspects of the Space
Environment In-Situ Suite (SEISS) of instruments which
comprises three instruments to provide data essential to NOAA’s
Space Weather Operations.

Sich 1M Fails to Reach Planned Orbit
Sich 1M is in a useless orbit due to a shortfall in the orbit
circularisation burn. The first burn of the third stage rocket
carried the spacecraft (together with the MK-1TS subsatellite) tonear the planned 650 km apogee where the third stage fired
again but failed to impart sufficient velocity increase tocircularise the orbit. The shortfall was about 100 m/s resulting ina perigee well below 300 km.

NOAA N Launch Preparations Under Way
At the time of writing in mid-January, a Boeing Delta II rocket
stands at Space Launch Complex-2 on the Western Range at
Vandenberg AFB in California. The solid rocket boosters havebeen attached and the second stage is due to be added shortly.

Meanwhile, in a NASA payload processing facility nearby, thespacecraft has been mated to the Delta II payload attach fitting
and placed on a test stand. Checks will continue right up to thelaunch which is expected on March 19.

GOES-R Development Continues Apace
Although the launch is still more than seven years away,
development of the next-generation GOES geostationary
satellites is accelerating. The first, GOES-R, is planned to beorbited in 2012 and will have a greater capability than theimminent GOES-N spacecraft.
The new Advanced Baseline Imager will have about 16 channels
which will have similar characteristics to those on the SEVIRI
instrument on EUMETSAT’s second-generation Meteosats. The
GOES-R series will also carry a Hyperspectral Environmental
Suite (HES), a multi-purpose sounder/imager. One of its
capabilities will be to better monitor and study coastal waters, atask which has largely been carried out by lower polar-orbiting
spacecraft. With the high resolution of HES, coastal monitoring
can be continuous from a ‘stationary’ platform and scientists
from NOAA, NASA, and the Office of Naval Research met
recently to discuss how to maximise the benefits of this new
capability.

Two-line elements show that the mean motion increased from15.352 to 15.381 in the four weeks following launch and the rateof increase will accelerate over the coming months as apogee
falls. A fiery end seems inevitable in a few months’ time asreports that on-board thrusters can compensate for the third
stage underperformance are probably incorrect.

Tsunami Wave Heights Measured from SpaceNOAA scientists were able to utilise satellites to measure theheight of the devastating tsunami waves that followed theSumatran earthquake in December (see images on page 17).
Scientists at NOAA’s Laboratory for Satellite Altimetry (LSA) in
Silver Spring, MD, examined data from the four satellites,
TOPEX/Poseidon, Jason 1, Envisat and the US Navy’s Geosat
Follow-On. They deduced that two hours after the ‘quake thewave height was 60 cm and had reduced to 40 cm after a further
75 minutes. After almost 9 hours the wave had covered most of
the Indian Ocean and was 5-10 cm, except in the Bay of Bengal
where 25 cm high waves were still bouncing around.
These figures may seem small, and in the open ocean suchwaves are harmless, but the wavelength is of the order of
100 km so the volume of water in a wave is colossal. It is not
until the front of the wave reaches shallow water and slows downthat the back of the wave catches it up and increases theamplitude to such an extent that massive devastation isinevitable.
Concluded on page 27 ...

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23

GEO Quarterly No 5

Group for Earth Observation

March 2005

Francis Bellcan contact me by post or e-mail—there
will be no charge. I undertake to fulfil
requests but with copying and subsequent
distribution the timescale is uncertain. My
contact details can be found on page 1.

I was delighted to receive, on behalf of
GEO, an invitation from NOAA to attend
the Satellite Direct Readout Conference:‘A Decade in Transition’ organised by
NOAA Miami, in December 2004. The
conference lasted five busy days and several evenings.
Although I paid my own expenses forhotel, flight and registration the organisers
did provide GEO with a display area at no
cost to us. I hope there was a suitabletrade-off with GEO putting on an interesting display and distributing a copy of ourQuarterly publication to almost all the conference delegates. In our display area,
GEO ran four and a half days of computerpresentation about our group. On thestand we also had three APT receivers
and two Hot Bird-6 receivers plus relevant
literature.
I don’t know the exact numbers attending
the conference because delegates tended
to come and go over the five days. I think
190 delegates from 30 countries would bea close approximation for those present
on each of the five days.
GEO was included in the conference
programme and I made a presentation
giving some details of GEO’s background,skills, our membership numbers andgeographical distribution. I also explained
our interests in weather satellites. I was
also a panel member during one of theconference sessions—an open discussion
concerning the global co-ordination ofenvironmental satellite data. My best
contribution here was to comment on thegrowing and worldwide membership of
GEO.
The conference organisers kindlypresented me with an award after these

Darrell Robertson (left) pictured presenting
Francis Bell with the award for GEO’s
presentation.

two sessions. I will ensure that this award
travels with me to be displayed at any
future GEO events.
The conference programme was detailed
and extensive. I cannot possibly cover ithere except in the broadest terms.
Day 1 - NOAA programmes, World
Meteorological Organisation(WMO), NOAA geostationary
and polar satellites, European
satellites.
Day 2 - International co-operation ,WMO, NOAA, international useof data.
Day 3 - Current polar systems,
international co-operation,
EUMETSAT and polar systems,
future polar orbiting systems,
NPOESS.
Day 4 - GEO systems, current status,
performance, LRIT, GOES R,
EUMETSAT services.
Day 5 - Global perspective, data
dissemination, open discussion.

The text and visual materials whichaccompanied most of the presentations
were projected from CD-ROMs using acomputer system and the conference
organisers will shortly be making all thesepresentations available on a single
compilation CD-ROM. I will try to makethese available to any GEO member who
would like one. The CD will be free but
there must be a modest handling charge.

GEO’s team at Miami
Nadine and Francis Bell24

UK members should send me theirrequest by post, enclosing four first classstamps. Members who live outside the UK
www.geo-web.org.uk

I enjoyed my time in Miami but it was not
as glamourous as you might think being
buried in conference rooms at the bottomof a large hotel for most of the time.
Without a doubt the most interesting,valuable and pleasurable times werewhen meeting and talking to those people
involved in the design, construction,
operation and use of weather satellites. I
learned about the weather satellite
community and I hope they learned about
GEO.
Acknowledgements
I must thank all the following for theircontributions to the success of theconference.
I’m not sure who all the organisers were,
but special thanks to Darrell Robertson,
Ken Ashworth, Eric Madsen and Valerie
Thompson for supporting GEO’s presenceat the conference and of course to NOAA
for its administrative structure which provided a smooth running five days.
I am also grateful to NOAA and NASA for
providing GEO with a display area and to
Les Hamilton for preparing the GEO‘Powerpoint’ presentation.
Finally, I cannot end without thanking mywife, Nadine, who helped me with everything, including looking after GEO’s standwhile I was attending the conference presentations. Try weighing a GEO Quarterly,
then multiply it by 250 and take the lot on
a transatlantic flight with the rest of yourluggage: You need help! Thanks to
Nadine. She is unpaid but very supportive
within GEO.

The GEO stand at Miami

March 2005

Group for Earth Observation

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 blanke-mail containing the word ‘subscribe’ in its Subject line is
all that is required. Some of the more useful groups andtheir contact addresses are listed below.
GEO-Subscribers
This is a group where GEO members can exchange
information relating to either GEO itself or Earthobservation 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 ATOVS and HRPT Reader programs, the remapper
GroundMap, and the MSG Data Manager
e-mail: SatSignal-subscribe@yahoogroups.com

MSG-1

GEO Quarterly No 5

The Editor is always on the lookout for articles and images forinclusion in GEO Quarterly. These can relate to all aspects ofEarth Imaging, especially:
•
•
•
•
•
•
•
•

Technical articles concerning relevant hardware
Construction projects
Weather satellite images
Reports on weather phenomena
Description of readers’ satellite imaging stations
Activities from overseas
Letters to the Editor
Problems and Queries for our experts to answer

Contributions should of course be original and, where possible,
should be submitted to the editor in electronic format (floppy
disc, CD or e-mail attachment). But we will also accept
handwritten or typed copy should the need arise.
Please note, however, that major articles which contain large
numbers of satellite images, photographs or other illustrations
should be submitted well before this date so that they can beprepared and made up into pages in time for publication.
Images and Diagrams

A forum dedicated to Meteosat-8 (formerly MSG-1), where
members can share information about the reception
hardware and software.
e-mail: MSG-1-subscribe@yahoogroups.com

Images can be accepted in any of the major bitmap formats, e,g,
JPG, BMP, GIF, TIFF etc. Images in both monochrome andcolour are welcomed for inclusion. Line drawings and diagrams
are preferred in Windows metafile and postscript formats.
We can also scan original photographs, negatives and slides.

Weather Satellite Reports
A group providing reports, updates and news on
operational aspects of weather satellites.
e-mail: weather-satellite-reportssubscribe@yahoogroups.com

If your article submission contains embedded images anddiagrams, please note that we do also require, in addition,individual copies of each image or drawing which is notembedded within the article, for 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.

WXtoImg
Users of the WXtoImg software package for capturing andimaging NOAA APT can air their problems, discuss its
features and ask questions about it.

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

e-mail: wxtoimg-subscribe@yahoogroups.com.

Contract for MSG-4 Signed

Member’s Advertisement
Does anybody have any receiving equipment for C-Band:
that is, 4.0 GHz? I have a 2-metre dish and receivers butlack a feed horn LNB. I would like to gain experience with
C-Band for members of our GEO group who are outside thefootprint of Hot Bird-6 (which operates in the 11 GHz Ku
Band). Reception will not be easy within the UK but it should
be possible. Help on behalf of our group would beappreciated. Or, if this is a waste of time, I would appreciate
it if somebody could tell me please.
Francis Bell (contact details on page 1)

The €135 million contract for a the fourth Meteosat Second
Generation spacecraft was signed at ESA Headquarters in Paris on
November 3, 2004 to ensure continuity of European meteorologicalsatellite services for many years to come.
French firm Alcatel Space is the prime contractor while EUMETSAT
will finance, launch and operate the satellite. Delivery is expected in
2007.
MSG-2 is scheduled for launch in June 2005 and will be placed in aparking orbit until required to take over from Meteosat-8. Collectively
MSG-1 to -3 are projected to provide up to 15 years of meteorologic
coverage, and MSG-4 should extend this significantly.

www.geo-web.org.uk

25

GEO Quarterly No 5

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March 2005

Peter Wakelin
Part 1 briefly described some of NASA’s orbiting spacecraft
other than those weather satellites we are familiar with. Part 2
describes some forthcoming satellites (together with Aura which
has been launched recently) which may be of interest to readers.
NASA’s two papers presented to the 32nd meeting of theCoordination Group for Meteorological Satellites held in Sochi,
Russia, in May 2004 form the basis for this article and I am
indebted to the CGMS Secretariat for making them available.

spectrometers to measure carbon dioxide concentrations
accurately over the entire globe for a period of at least two years.
GPM (Global Precipitation Measurement)

CloudSAT (Measurements of global cloud properties)
This cooperative mission with Canada will use anovel radar technique to examine the verticalstructure of clouds in great detail and provide a
new observational capability from space. It will
be launched later this year to a 700 km sunsynchronous orbit allowing global coverage.

Although not due up for three years, GPM is being designed andbuilt on the success of the Tropical Rainfall Measuring Mission(TRMM) which is currently operational. GPM, like TRMM is a
joint mission with JAXA (Japan Aerospace Exploration Agency)
but will enter a higher inclination orbit than TRMM’s, permitting
observations over most of the globe.

Aura (Measures Earth’s ozone, air quality and climate)This spacecraft was launched several months ago into a 700 km
sun-synchronous orbit with its ground track repeating every
16 days: it carries a suite of instruments to make comprehensive
measurements of the trace gases in the atmosphere. The UK
and the Netherlands provided some of the instruments whichmeasure ozone, aerosols and several key atmosphericconstituents that play an important role in atmosphericchemistry, air quality and climate.
CALIPSO (Cloud-Aerosol and Infrared Pathfinder Satellite
Observations)
CALIPSO will fly information with CloudSAT
and Aqua (see part 1) toprovide a comprehensive
characterisation of thestructure and compositionof clouds globally and in all
weather conditions. CALIPSO, which is expected to be launchedlater in 2005 with CloudSAT, is a cooperative mission withFrance and carries a high-resolution wide-field camera, apolarisation-sensitive LIDAR (read more about LIDAR on
page 10) and an imaging infrared radiometer.
OCO (Orbiting Carbon Observatory)
Expected up in late 2007, OCO will carry three grating infrared

GPM’s instruments are a dual-frequency precipitation radar, amicrowave imager plus a constellation of passive microwave
radiometers which will help to improve water management,
agricultural efficiency and disaster management.
HYDROS (The Hydrosphere State Mission)
Planned for launch into a 6 am/6 pm sun-synchronous orbit latein 2006, HYDROS will provide the first global views of Earth’schanging soil moisture and land surface freeze/thaw conditions.
Its radar and radiometer data are expected to lead to a better
understanding of the processes linking water, energy and carbon
cycles.
Aquarius (Global maps of salt concentration of the ocean
surface)
Scheduled for a late 2008 launch,
Aquarius will measure global sea
surface salinity from its 600 km sunsynchronous orbit. Its radiometer willmeasure seawater emissivity at awavelength sensitive to salinity withthe aim of modelling the processes
that relate salinity variations toclimatic changes and to understandhow these variations influence thegeneral ocean circulation.
NPP (NPOESS Preparatory Project)This spacecraft, scheduled for launch late next year, will extend
the series of observations started by the Aqua and Terrasatellites in NASA’s Earth Observation System, thus bridging the
gap between EOS and the next generation National Polarorbiting Operational Environmental Satellite System (NPOESS)
which will not become operational before 2010. A more detailed
description of this spacecraft will appear in a future issue of GEO
Quarterly.

26

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GEO Quarterly No 5

LDCM (Landsat Data Continuity Mission)
Many readers will be familiar with the Landsat programme whichbegan with the launch of Landsat 1 in 1972. LDCM will continue
the 30 m resolution global land surface imagery of its
predecessors but will be commercially owned and operated.
The launch date has yet to be determined.
OSTM (Ocean Surface Topography Mission)

OSTM is a cooperative effort between NASA, NOAA,EUMETSAT and the Space Agency of France (CNES) and will
be a follow-on to the Jason 1 mission (see Part 1). With
improved instrumentation and a greater swath width, sea
surface topography measurements will become more precise.
OSTM will operate from a circular 1336 km orbit and the launchis scheduled for late 2007.
Further information on all the above spacecraft can be found byentering the satellite’s name in any Internet search engine.

... Continued from page 23

India’s Launch Site Escapes Tsunami Damage
Although lying on the east coast of India, the Indian Space
Research Organisation’s satellite launch facility at Shiharikota,
north of Chennai (Madras), escaped serious tsunami damage
on December 26. Most damage and loss of life occurred further
south. The Indian authorities remain very secretive about theirfacilities on the Indian-administered Andaman and Nicobar
Islands, which suffered great damage and loss of life, so it is notknown if their tracking station at Port Blair was affected.

China Launches Remote Sensing Satellite
The 300 kg Shiyan 2 remote-sensing satellite, developed by
DFH Satellite Co, was launched on a Long-March 4 rocket on
November 6 from the T’ai Yuan Satellite Launch Centre in
China’s Shanxi Province. It achieved the planned 700 km sunsynchronous orbit and will be used for land resource surveying,environmental monitoring and protection, city planning anddisaster monitoring. This was China’s eighth successful launch
in 2004 which is a record for that country.
Several Weather Satellite Launches Expected in 2005
Although further slippages are likely, it seems that 2005 will bea good year for weather satellite launches. Hopefully, they will
all do better than Sich 1M. The expected month of launch forseveral satellites is listed below.
MTSAT 1RNOAA NGOES N
CloudSAT/Calipso
MSG-2
Monitor E
DMSP 17

February
March
May
May
June
June
June

The first METOP was expected to be launched later this year
but has been delayed until early 2006.

After remaining a solid mass throughout Southern Hemispherespring and the first part of summer, sea ice in McMurdo Sound
finally began to break up during January 2005. In an annual
cycle, thick ice freezes on the water during Antarctica’s frigid
winter then breaks and drifts into the Ross Sea during thesummer. This year the process has been disrupted by the giant
80 mile long B-15A iceberg which blocked the currents thatusually clear out the Sound, where, as late as the first week ofJanuary, the ice remained intact.
In early January, temperatures increased and a powerful storm
moved over Antarctica. Strong winds churned the ocean, and,along with the warmer temperatures, may have contributed tothe break-up of the ice. When the clouds cleared on January 13,
the Moderate Resolution Imaging Spectroradiometer (MODIS)
flying onboard NASA’s Terra satellite revealed that the formerly
solid ice had been broken into chunks.
Image: MODIS Rapid Response Team, NASA-Goddard Space Flight Center

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27

GEO Quarterly No 5

Group for Earth Observation

March 2005

Rob
AlblasIntroduction
During the past decade I have written
several programs for decoding highresolution transmissions from weather
satellites. These included both HRPT and
CHRPT from polar orbiting satellites aswell as HRI, the high-resolution broadcast
format of Meteosat-7 and earlier European
geostationary satellites (better known asPDUS).
With the launch of Meteosat-8, the first of
the new generation of all-digital geostationary weather satellites, a new data
format has come into the picture. The
broadcasted formats are called LRIT and
HRIT which I jointly refer to as XRIT. The
main task is the translation of the XRIT
formats into pictures. I have created a newprogram, XRIT2PIC, for the purpose.
Almost everything XRIT2PIC does is also
possible with David Taylor’s MSG DataManager. XRIT2PIC also duplicates a few
of the features of GeoSatsignal and MSG
Animator. Still, there are a number ofreasons why you might also wish toconsider using XRIT2PIC.
• You do not need a powerful computer;
XRIT2PIC runs fine on a PC
containing just 256 Mb RAM (in aspecial mode just 64 Mb; in non-GUI
mode even less).
• Non-GUI mode is possible, where
XRIT2PIC can work in batch mode totranslate XRIT pictures.
• There are executables not only for
Windows but also for Linux (no ‘Wine’tricks!)• It is free software. The source code isavailable and it may be compiled for
SUN/Solaris and Mac computers. (Ifyou require the source code of the
Wavelet translation part, a license isrequired, though. Contact EUMETSATat OPS@eumetsat.de if you need it.
No license is required to use theactual Wavelet library)
Program Features• LRIT/HRIT files received via the
Skystar-2 hardware are dumped on to
the hard disc by the Tellique software.
• XRIT2PIC can process the following
picture formats embedded within thesefiles: JPEG 8-bit, JPEG 12-bit,
Wavelet (8 and 10 bit) as well assome uncompressed formats.
• The Images you create can be output
28

as JPEG 8-bit, PGM 8-bit, PGM 16-bit
and PPM 24-bit (colour).
• You can overlay coastlines andcountry boundaries• Extraction of messages• Movie generation is possible using theexternal program Mencoder (freely
available for Linux and Windows) and
executed by XRIT2PIC• ‘Live’ display of selected channel(s)• Immediate deletion of unwanted
channels during reception• Built-in viewer• Automatic launch of your favourite
viewer after translation of a picture

A complete set of image segments from
Meteosat-8 (LRIT and HRIT data) consistsof 16 x 8 + 24 = 152 files, and a separate
file is downloaded for each segment.
During a 24-hour period there are 14 592
files from Meteosat-8 itself plus more than
500 additional files from ‘foreign’ satellites.
Together with prologue, epilogue andmessage files this means a total of morethan 15 000 files are received each day.
XRIT2PIC orders all these files andpresents them in a tree structure as shownin figure 2. Each dataset from a particularsource, type and time gets its own line in
the tree.

More features will be added in the future.
Figure 1 shows a functional overview of areceiving station using XRIT2PIC as its
HRIT/LRIT translator.
Files and Pictures
Table 1 provides an overview of the files
dumped in your ‘Received’ directory by the
Tellique software. These include data fromsome foreign satellites, also broadcast by
EUMETCast.

Type

Sourcesatellite

No ofchannels

HRIT

MET-8

11

8

HRIT

MET-8

1 (HRV)

LRIT

MET-8

LRIT

Opening a tree branch shows all channels
and other related data and displays all
segments, including north-south range ofeach segment. In this example the VIS008
channel is shown in red because one
segment (No 5) is missing.
If you select a channel (green) and thenpress the <Preview> button, a simple
viewer will pop up and display the picture.
This viewer includes a few simple features
such as zooming, brightness controls, etc.

Segments per channel Lines per(= Number of files)
segment

Total numberof lines

Format464

3712

Wavelet-10

24

464

11136

Wavelet-10

5

8

464

3712

JPEG-8

MET5-73

5 or 10500

2500 or 5000

Wavelet-8

LRIT

GOES9

3

6

464

2784

Wavelet-8

LRIT

GOES102

4 or 7464

3248

Wavelet-10

LRIT

GOES12

3

4 or 7464

1856 or 3248 Wavelet-10

Table 1 - Overview of file types

Figure 1 - Functional overview of XRIT2PIC
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March 2005

Group for Earth Observation

GEO Quarterly No 5

The zooming is achieved via keyboard
hot-keys (e.g. ‘i = zoom in, ‘o’ = zoom out,‘f’ = full size). If you place the mouse overthe ‘Help’ button at the top right handcorner of the viewer window—without
clicking—you see these in a drop-downlist. You can also navigate around azoomed image using the cursor keys.
To save an image, either press the<Export> button at the foot of the main
screen or use the <File/Save> option on
the image viewer itself: doing either will
generate a JPEG or PGM file.
Alternatively, if you select two or morechannels (green lines) or the full
unexpanded dataset (blue line) before
clicking the <Preview> button, the<Translate list> window will pop up(figure 3). Here you can select thechannels you wish to translate: when you
click <Do it> they will all be translated
into images, each in its own viewer
window.

Figure 2 - Directory tree of MSG files

Figure 3 - Selecting multiple channels

By default, exporting is done without
introducing extra loss: 10-bit Wavelet istranslated into 16-bit PGM while JPEG isgenerated without decompressing orcompressing the data. These methods
have a few small drawbacks:• PGM 16-bit does not seem to be avery well defined format—mostviewers support it, but some viewers
swap the LSByte and MSByte• A PGM 16-bit image file is twice thesize of a PGM-8 one• Generating JPEG from LRIT without
decompressing or compressing gives
an upside-down picture
If a little information loss is acceptable,
XRIT2PIC can also generate PGM 8-bit
and uninverted JPEG from any source(JPEG 12-bit, used in early versions of
the program for the HRV channel, isn’t
used any more although the program still
supports this format).
Figure 6 - A typical colour-composite Meteosat-8 image
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29

GEO Quarterly No 5

Group for Earth Observation

For historical reasons, Meteosat-8 scans
its images from south to north. In the ‘old’
days(Meteosat-7
andearlier)broadcasting a single picture at thehighest resolution (AIV format) took nearly
30 minutes! So once the picture wascomplete, the southern part of the globe
was already more or less ‘out-of-date’,
while the Europe part that we areinterested in was more up-to-date.
Scanning from south to north means
upside-down pictures. To flip a pictureformat like JPEG it has first to be
decompressed, then flipped, and finallycompressed again. Because JPEG is a‘lossy’ format, each compression
generates extra image loss (each LRIT
channel contains 8 segments, whichmeans that 8 JPEG files have to be
combined. This process is possible
without doing an extra decompression
and compression cycle).

problems when trying to generate movies
at full resolution (3712 x 3712 pixels), theresolution may be lowered. Bothmonochrome and colour movies are
possible. This feature uses an external
program called Mencoder, which is freely
available for both Linux and Windows.
XRIT2PIC first generates JPEG files for all
selected items and stores these in a
special directory. Then the program
activates Mencoder. If the movie file isgenerated all the used JPEG files will bedeleted.

The lossless Wavelet format is notsupported by popular viewers and istherefore always translated into a morecommon format like PGM and JPEG.
Colour Images and Boundaries
XRIT2PIC is also able to do some simple
data processing. For example, it is possible to combine several channels into
one colour picture. By default the VIS006,
VIS008 and IR-016 channels are used,
but other user-selected combinations arealso possible.
Colour pictures are generated if a dataset(blue line, figure 2) is selected and the<Enable> button in the <Colors> panel isactivated; both PPM and JPEG aresupported as output formats.

Figure 4 - Adding new files to the tree

Processing During Reception
The features described above refer todata that has already been received andstored on your PC. There are a few extra
features which make XRIT2PIC usefulduring ‘live’ data reception.
If the <Cont. update> button is pressed
the program detects new files as they are
downloaded by the Tellique software(figure 4). These will be added to the tree

March 2005

structure.
If the <Show> button is checked a viewer
will pop-up, showing each picture as soon
as it has been received. Currently just one
channel can be shown properly at a time.
If the <Remove> button is checked a new
window pops up in which the channels
you want to save may be selected(figure 5). All other channels will bedeleted a few seconds after Tellique has
downloaded them. This can save a lot of
disk space!
Detecting one new file in a directory whichcontains thousands may result in speed
problems. If the <Move> button ischecked XRIT2PIC moves all ‘old’ files
into a ‘Done’ directory. The ‘Received’
directory is then empty, and it is easy todetect when Tellique adds a new file. This
file will then be added into the XRIT2PIC
tree structure and moved to the ‘Done’directory. This whole procedure repeats
itself every 3 seconds, provided the<Cont. update> button is active. You won’t
notice that the files are in a new directory;
whenever XRIT2PIC is restarted, it always
reads the files in both the ‘Received’ andthe ‘Done’ directory. (The <File/manage
files> menu opens a simple utility to move
all files back to the original received
directory, if desired).
Non-GUI Mode
XRIT2PIC may be used in a non-GUI
mode where raw XRIT datafiles aretranslated directly into JPEG/PGM files
without generating and displaying theimages, thereby saving greatly on
memory usage. This mode is also suitable
for automating translations.
Command line options are needed to tell
XRIT2PIC what to do. Once the job iscomplete, the program will quit. A typicalcommand line is shown in figure 7 at thefoot of this page.

It is also possible to overlay country
boundaries and/or coast lines on yourimages. EUMETSAT provides GIF files
with exactly the same size as the received
pictures, in four different versions.
• just coast lines• coast and country boundary lines• longitude/latitude marks• and all-in-one

MoviesThis will translate all HRIT files with achannel name starting with ‘VIS’ (e.g.
VIS006 and VIS008), for every day in
September 2004, with a time of 12:00.
Each picture will contain only segments 7
and 8 (which is Europe). So, this single
command will result in 30 x 2 = 60 picture
files. (Movie files may also be generated
this way.)

Last but not least, it is possible togenerate movies by activating the <Film>button in the <Translate list> window(figure 3). If you experience viewer(The asterisk (*) wildcard can be inserted
in several of the fields. Whereas ‘VIS006’
could have been entered to decode thatXRIT2PIC can project these files on to thereceived pictures, both for preview andexport.

Figure 5 - Selecting which channels to keep

XRIT2PIC -nogui -type H -chan VIS* -segm 7-8 -date 04-09-* -time 12:00
Figure 7 - A typical non-GUI command line

30

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March 2005

Group for Earth Observation

channel alone, ‘VIS*’ decodes all visible
channels. The date field expects the data
to be entered in ‘yy-mm-dd’ format. The
asterisk used in this example extends
decoding to every day of the month. Fulldetails of all non_GUI options are listed in
the XRIT2PIC Manual).
Now, if you place a non-GUI command (orseveral such commands) in a batch (.bat)
file, together with the command:del c:\tellique\received\*.*(assuming that this is the directory inwhich Tellique dumps its files), you can run
this .bat file periodically, each day, around
midnight. You can do this under Windows
with the ‘Task Scheduler’ utility (and under
Linux using the ‘Cron’ utility). This entire
process may run unattended for a year or
longer if you want, saving only the images
you want and leaving a clean hard disk.

GEO Quarterly No 5

Jaap Rusticus

As part of David and Cecilia Taylors’ report on the September 2004 meeting of
Werkgroep Kunstmanen in Utrecht, Netherlands, we pictured a unique miniaturised
receiver for Meteosat WEFAX, which featured a built-in display screen. The designer
was Jaap Rusticus, and he provided the following details about it in a conversation
with David Taylor.

Settings
XRIT2PIC has default settings foreverything, but in most cases a few
settings have to be changed. The mostimportant settings are:• the directory where Tellique dumps thefiles (‘Received’), and• the directory in which you want tosave the translated pictures. By
default, this is the XRIT2PIC directory,
but you can create your own ‘Pictures’directory if desired.
These directories may be on different
computers, if desired.
Also, the command to activate Mencoderwith all its options may be altered.

The Jaap Rusticus WEFAX receiver, pictured beside a teacup

Most often, a Meteosat-7 receiving system consists of a 1700 MHz downconverter
and a receiver, but because mine had to be small, I designed a two-channel oneboard receiver. This means that the input to the PCB is 1700 MHz and the output isaudio. It has a crystal filter and PLL-detector to give it a good performance.
The audio is fed into a signal demodulation board which is coupled to a 256 x 256
pixel frame storage board. These two boards were designed by a hobbyist friend ofmine, Johan de Lange from Amsterdam. Although it is based on the idea of the old
YU3UMV (1982) system, Johan gave it a completely new design and also developed
the double-sided PCBs. The display uses an old 2 x 3 inch television tube. The small
television set was built on pertinax and because I did not like that, I redesigned thetelevision PCB on to a video PCB.

Finally, the state of most buttons may besaved, so that the next time XRIT2PIC isstarted the state of these buttons will be
restored.
Installation
XRIT2PIC needs a few special library files:• GTK libraries• JPEG library• Wavelet library
All these library files, together with the
XRIT2PIC program itself, are available forboth Linux and Windows. They can be
downloaded from my website at:
http://www.alblas.demon.nl/
wsat/softwareOn the same page you can also find a linkto the EUMETSAT page with the overlay
files, links to download the MENCODER
program (needed for movie generation)and the XRIT2PIC manual containing all
the program and installations details.

The interior of the receiver showing the miniature TV tube

The antenna is a 9-element Yagi, constructed according to the design of Gunter Hoch(DL6WU) in UKW-Berichte. Mounted on the antenna is a three stage preamplifier
with a GaAsFET and two MAR-6’s. This has a noise-figure of 0.7 dB. Normally thisgives noise free pictures with the short Yagi but at Utrecht I used a too long a lengthof co-ax cable—I could not find a shorter one just before I took off for Utrecht.
The antenna signal passes through a 1700 MHz bandpass filter before entering thereceiver board. This filter suppresses the strong GSM signals in both the 1800 MHz
and the 900 MHz bands.
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31

GEO Quarterly No 5

Group for Earth Observation

Les Beeson recently joined GEO and send us a selectionof his WEFAX images. Les uses a 1-metre dish, withdownconverter and an RX2 receiver to capture the signals,
while the processing is accomplished by means ofEberhard Backeshoff’s JVcomm32 software. The image
above came from NOAA’s GOES-12, via Meteosat-7. The
image above, dating from September 3, 2004, shows
hurricane Frances advancing on Florida.
Les collects images regularly, and uses them to create
movies which, he states ‘.. are interesting in that they32

March 2005

show these hurricanes starting life on the equator, off thewest coast of Africa, and then spiral northwest over the
Atlantic. I have studied their movements for some years
now, and find them quite fascinating ..’However, as we announced on page 26 of GEO Quarterly
No 4, all wefax from EUMETSAT, plus the high-resolution
PDUS service will have ended forever by the end of 2005
(unless there is an unforeseen problem in commissioning
MSG-2). In the article that follows, John Tellick take anostalgic look back on a quarter of a century of Meteosat.

www.geo-web.org.uk

March 2005

Group for Earth Observation

GEO Quarterly No 5

John Tellick
If all goes well with this year’s launch andcommissioning of MSG-2 it will befarewell to all Meteosat-7 services from 0°
at the end of December 2005. Meteosat-7
was the last of the so-called ‘first series’ ofEuropean geostationary meteorologicalsatellites which have provided imaging
coverage of Europe, Africa, the Atlantic
and part of the Indian Ocean since theprogramme started in 1977.
Meteosat-1 was launched from Cape
Canaveral on a Delta rocket in November
1977. It’s radiometer failed prematurely in
November 1979 and there was a gap inservices
until
Meteosat-2 waslaunchedfrom
Kourou on an
Ariane-1 launcher
in June 1981.
Since then there
has been a continuous high quality
Meteosat-1 being
imaging service
prepared for service
withoutmajor
Photo: ESA
breaks.

February 1993 Meteosat-3 was moved
again, to 75°W, and extended Atlantic
Data Coverage (X-ADC) commenced
owing to the failure of the GOES satellite.
Meteosat-6 was launched in November
1993 but showed imaging anomalies(which had also to some extent affected
Meteosats -4 and -5). These anomalies
were corrected by software during dataprocessing operations at the Ground
Segment and the images returned to thesatellite for the direct read-out datatransmission to users.
Meteosat-7 was launched in September
1997 and injected into geostationary orbit
with such precision that considerable onboard fuel was saved. This has allowed
longer station-keeping activities andextended the transition period between
this final ‘series one’ satellite andMeteosat-8, the first of the ‘series two’
Meteosat Second Generation (MSG)
satellites.
Current Operations

Meteosat-3, a refurbished P2 engineering
prototype, was launched in June 1988 on
the first flight of the Ariane- 4 LP launcher(used to launch the rest of the series).
Thissatellite
quickly took overfrom Meteosat-2
whose on-board
fuel supply was
very
low
and
which
had
developed a highorbital inclination(movement aboveand below theequator from its Launch of Meteosat-3
nominal position
Photo: ESA
during each 24hour period).

Meteosat-7 remains stationed at 0° from
where it is currently transmitting analogue
WEFAX data, digital HRI (PDUS) data via
direct read-out dissemination and othernon imaging meteorological data services
and products as well as being a platform
for receiving and relaying environmental
and meteorological data transmitted byground- and ocean-based sensors, ships,
aircraft and balloons. The satellite’sradiometer scans the globe every halfhour in visible light (VIS), Infrared (IR) andwater vapour (WV) spectral channels.
The raw data is received and processedby EUMETSAT before being sent back tothe satellite and disseminated to end
users via the direct read-out service 24
hours a day. The HRI data is also
disseminated via the EUMETCast
service.

Meteosat-4, launched in March 1989, was
EUMETSAT’s first operational satellite(see later), and signalled the beginning ofthe ‘primary service’. Meteosat-5 followedin March 1991 and with two operational
upgraded satellites in orbit high level ofservice could now be guaranteed.

Meteosat-6 is stationed at 10°E andprovides the Rapid Scan Service (RSS),
which provides a 10 minute scan of theEuropean sector to track, and provide
timely warnings of, severe weather acrossEurope. This service is disseminated via
EUMETCast only.

In August 1991, in anticipation of a gap in
GOES satellite coverage, Meteosat-3 wasdrifted to 50°W to began the EUMETSAT
Atlantic Data Coverage (ADC). In

Meteosat-5 was moved to 63°E between
January and May 1998 and that Julycommenced the INDOEX multi-national
experiment, studying atmospheric polwww.geo-web.org.uk

lution, solar radiation and the interactionof clouds over the Indian Ocean. This
service (in the absence of a Russian
GOMS satellite) was extended to become
the EUMETSAT Indian Ocean Data
Coverage (IODC) service. This coverageis due to last a few more years till a new
GOMS satellite is operational in the area.
Meteosat-5 continues to provide highquality, vital imaging of the Indian Ocean
area but is now running very low on onboard fuel. Its increasing orbital inclination
has not been corrected for some years
and it is due to be replaced by either
Meteosat-6 or -7 once MSG-2 has beensuccessfully commissioned.
Meteosat-5, now 14 years old, has only
one direct read-out channel operational
and transmits principally HRI (PDUS) data
but also a single whole globe IR WEFAXITOT frame during each 24 hour period.
EUMETSAT and Meteosat Operations
EUMETSAT and its eventual control overthe satellites evolved over several years,
beginning in 1972, when an eight nation
Meteosat development programme wasinitiated by the European Space
Research Organisation (ESRO) which
was a predecessor of the European
Space Agency (ESA).
One satellite was provided for, withseveral spares. However, these sparesand the refurbished engineering model
enabled the launch of Meteosats 1, 2
and 3.

First Meteosat-1 image - December 9, 1977
Image: © ESA

In December 1977 there was global
geostationary coverage for the first time,from five geostationary weather satellites:
three from the US, one European and one
Japanese. A year long global weather
experiment had started.

33

GEO Quarterly No 5
• January 1981 - An Intergovernmental
Conference in Paris agreed to set up
EUMETSAT to assure the continuity of
meteorological satellites in Europe.
• March 1983 - ESA begins the Meteosat
Operational Programme (MOP) in
anticipation of the establishment of
EUMETSAT. This guaranteed theconstruction and launch of Meteosats -4,-5 and -6.
• June 19, 1986 - EUMETSAT finallybecame a reality and at the first meeting of
the EUMETSAT Council it was agreed thatits headquarters would be in Darmstadt,
Germany.
• August 1986 - The EUMETSAT Director
arrives in Darmstadt to begin the
recruitment of staff, to be housed in
temporary accommodation which, it turned
out, had to last for 9 years.
• May 1991 - Initiation of EUMETSAT’s
Meteosat Transitional Programme (MTP)and funding for the construction, launchand operation of Meteosat-7 until the year
2000 (though that has since been
extended).
• November 1992 - The EUMETSAT Council
agree on a networked configuration for
future ground segments and a new groundsegment for MTP with many facilities. This
was to be located in the future EUMETSAT
headquarters, with a new Primary Ground
Station at Fucino in Italy.
• August 1993 - The foundations for the new
EUMETSAT headquarters were begun.
• September 1994 - Staff preparing for the
new EUMETSAT ground segment (seelater) move into the Operations Wing
whilst construction of the remaining partsof the building continued. The newheadquarters were inaugurated in June
1995.
• November 1993 - Agreement on the startof reparatory programme for the
EUMETSAT Polar System (EPS).
• June 1994 - Agreement was reached on
the start of the full programme for MSG,
with provision made for procurement of
three new satellites of advanced design,
their launch and operation for 12 years.
• October 1994 - Meteosat images received
by the new EUMETSAT Primary Ground
Station in Fucino are successfully relayed
via a commercial satellite to the new
operations centre in Darmstadt and used
for test and development of the Mission
Control Centre.
• September 1995 - Encryption of Meteosat
HRI data is implemented to safeguard andcontrol access to, and use of, the highresolution data.
• November 1995 - Full Meteosat operations
controlling Meteosats -5 and -6 begin via
the new facilities at EUMETSAT’s
Darmstadt headquarters and PGS at
Fucino (operations had formerly been
carried out by ESA’s European Space
Operations Centre (ESOC) in Darmstadt).
• December 1995 - Formal transfer ofMeteosat operations from ESOC to
EUMETSAT.
• June 1999 - Full unconditional approval for
EPS.
• Sept-Nov 1999 - The stand-by satellite,
Meteosat-6, is used for rapid scanning

34

Group for Earth Observation

March 2005

Interior of the ESOC Control Centre. The Meteosat test card is visible at lower right
Image: © EUMETSAT

over the European Alpine region for the
Mesoscale Alpine Programme (MAP)
intensive observation phase.
• August 2002 - MSG-1 is launched andsubsequently very accurately placed ingeostationary orbit, thereby saving
considerable on-board fuel (launch—ESA,
orbit transfer—ESOC, operations following
successful transfer to geostationary orbit—
EUMETSAT).
• October 2002 - A solid state power
amplifier (SSPA) fails during thecommissioning tests on MSG-1.
Commissioning is halted pending theoutcome of an enquiry.
• April 2003 - Trials begin, disseminating
MSG image data via the alreadyoperational EUMETSAT Multicast
Distribution System being transmitted in
the Ku-band by EUTELSAT’s Hot Bird
satellite system at 13°E. (This was later
renamed EUMETCast following successful
trials).
• January 2004 - MSG-1 fully operational
imaging service begins (via EUMETCast).

Following normal convention, MSG-1 has
been renamed as Meteosat-8: hence mytitle ‘Farewell Meteosat – Welcome
Meteosat’. Construction, launch andoperation of a further MSG satellite,
MSG-4, has subsequently been agreed.
MetOp, the first European polar orbiting
satellite is due for launch in late 2005.
Discussions are already under way on therequirementsforMeteosat Third
Generation (MTG).
Remember.
• Meteosat-7 services are due toterminate at the end of December
2005—unless you swing your antennaround to Meteosat-5• WEFAX users in Europe will haveblank screens.
• You cannot use your Meteosat-7
receiving system for reception of Hot
Bird-6 EUMETCast nor any direct
read-out LRIT services from MSG-2, 3
or 4.
The Meteosat series has served the world
well, on some occasions from threedifferent locations, during its 27 years
service—and continues to do so.
This mantle has now been taken on by
MSG-1 which, as Meteosat-8 with its
advanced
SEVIRI
radiometer,isproducing much higher resolution imaging
in 12 spectral channels every 1/4 hour, an
enormous advance in the amount of vital
meteorological data produced 24 hours a
day by EUMETSAT.
Acknowledgement

The Fucino ground station in Italy
Image: © EUMETSAT

www.geo-web.org.uk

I would like to thank and acknowledge thehelp and support I have received fromEUMETSAT in preparing this article.

March 2005

Group for Earth Observation

GEO Quarterly No 5

Rob Denton G4YRZ, who lives in Worksop, Nottinghamshire,
England, provided this NOAA-17 image showing excellent detail wellto the east of the Black Sea, and including much of the Caspian Sea.
Rob used the Wxsat capture software and a WIMO crossed dipole
mounted on his chimney. No pre-amp used. Rob wonders if any otherreaders manage to image so far to the east using basic APT
equipment.
If you do, why not write in and let us hear about it?
Contact editor@geo-web.org.uk with your experiences and images.

NOAA 17, 08:29 UT on August 29, 2004
www.geo-web.org.uk

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GEO Quarterly No 5

Group for Earth Observation

March 2005↓←

This is the NOAA-17 channel-2 image from 18:04 UT on August 13, acquired approximately 12 hours prior to the Union County hailstorm.
There is little activity over the Clayton area (marginal arrows), but thunderstorms can be seen brewing over Arizona and western New Mexico.
Telemetry: NOAA SAA - Processing: HRPT Reader and Groundmap

36

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Group for Earth Observation

GEO Quarterly No 5

Ask anyone where glaciers are to be found, and the mostprobable answer will surely be the name of one of the planet’s
highest mountain ranges: the Alps, Himalayas, Rockies. The
more discerning reader might also add the names of some of
the Earth’s great polar land masses: Antarctica, Greenland,Baffin Island. But the State of New Mexico in the USA?
Surely not!
Well, prepare for a surprise! During freak weather conditions
last August, a unique and unexpected weather phenomenon
resulted in the overnight appearance of New Mexico’s veryown ‘glacier’. Here is the tale of that amazing occurrence.
The scene is Union County, often described as the ‘Crossroadsof the Southwest’, nestling at the northeast corner of New
Mexico, in an area bordered by the Colorado, Texas and the
Oklahoma panhandle. The county capital is Clayton, a citywith a population close on 2500, situated about 10 kilometres
west of the Texas border at an elevation of 1538 metres.
During winter, the minimum temperatures do certainly drop
below freezing, but such conditions have never been recorded
during August, when the average minimum overnighttemperature is 15°C and the daily mean is 22°C. Definitely
not conditions conducive to the formation of a glacier!

Figure 2 - Water flowing between ice cliffs 5 metres highAbnormal weather conditions near Clayton around midnight
on Friday August 13 resulted in millions of tiny hailstones
combining into a mass of ice at least 5 metres thick thatpersisted for almost a month before finally melting away.
Geologists and meteorologists dubbed this the ‘Union County
Glacier’.

Figure 3 - View upstream from the same location

Figure 4 - An ice cave cut into the ice

Figure 1 - A GOES-12 infrared satellite image of the storm NOAA/National Weather
Service courtesy UCAR Joint Office for Science Support.

During early August a succession of four cold fronts
moved down from the north, helped along by a highpressure cell stalled over Alaska. These fronts met
humid air moving up from the Gulfs of California and
Mexico, each time resulting in elevation of theunstable humid air to form bands of intense
thunderstorms across the Eastern Plains. On

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March 2005

August 11, a particularly strong cold front swept acrossthe Eastern High Plains, lifting humid air laden withfresh moisture. Showers and many thunderstorms werereported across the State during the following three days.
The most severe of these, which included falls of large
hail, occurred between the 12th and the 14th.
Residents of Clayton, Sedan (another community about 20
miles to the south) and the areas in between will longremember one particular storm that hit around midnight
on Friday August 13 and its spectacular aftermath.
Figure 1 is a GOES-12 infrared satellite image acquired at
08:30 UT (around local midnight) on August 14, 2004,
showing the southwestern United States and Mexico.
Cloud-top temperatures are indicated by colour according
to the scale at the foot of the image. Yellow and orange
represent cloud tops colder than -50°C. The tiny orange
speck above and to the right of the large orange area on
the image represents the top of the intense thunderstormthat affected the Clayton/Sedan area.

Figure 6 - The normally dry tributary of Sand Draw

they encountered what for all the world looked like a
glacier. Figure 2 shows Randy Podzemny standing near
the bottom of the draw as water from the previous night’s
deluge and the melting ice flows between ice cliffs up to 5
metres high. Note the bedding patterns in the ice caused
by varying amounts of debris and soil deposited with thehail. Figure 3 shows the view upstream from the same
location while figure 4 depicts a cave cut into the ice by
the torrent of runoff.
The overnight hail had filled the drainage tributary to aheight of approximately 5 metres and vertical ice cliffs 8
meters wide and some 100 metres long framed the torrentof water flowing through the normally dry channel(figure 6).

Figure 5 - Map showing the location of Clayton,
Union County, New Mexico

What this storm lacked in size (it was estimated to be only
some 12 square kilometres in area) it more than made up
for in intensity. Hail accumulations reaching 30 cm were
followed by as much as 7.5 cm of rain. Indeed, so muchrain fell in such a short period of time that the pea- andmarble-sized hail was carried along as sheetflood before
ending up being concentrated in a small, normally dry, 5to 7-metre deep drainage tributary to the gully known as
Sand Draw. Approximately 13 km south of Clayton, thistributary runs beneath the road through a drainage
culvert.
The hail was being driven along in such quantities by the
deluge of rain that it piled up at the entrance to theculvert which was unable to handle the flow. Hail backed
up along the gully, behind the culvert, as rain continued
to flow across the fields, through the tons of ice, and on to
the highway. Some time during the night the stream offlowing water cut a new, sheer-sided canyon through theheap of ice.
Early on the Saturday morning, Barbara Podzemny andher husband Randy were driving north from their homenear Sedan—where they had experienced only about 2 cm
of overnight rain, and no hail—towards Clayton when38

Everyone who encountered the glacier on that Saturday
morning, and for several days thereafter, were astonishedby what they saw. By 6:30 a.m. that morning they could
look out across what appeared to be a sheet of ice morethan 100 metres long on the west side of the road with astream, complete with new little waterfalls, flowing
through a sheer-sided canyon cut by the water throughthe glacier. Later in the day the ice had compacted to theextent that people could walk across the top of the glacier
without sinking in.
Although hail is commonly formed in thunderstorms, thedimensions of this accumulation are unique. The ice
remained for nearly a month in spite of long sunnysummer days and temperatures well above 25°C.
Acknowledgments• to Barbara Podzemny for granting GEO use of her original
photographs of the Union County Glacier to illustrate this article• to Jane C Love, editor, for allowing us to draw extensively on her
original article ‘The Union County Glacier’, printed in theNovember 2004 issue of the professional journal New Mexico
Geology (vol. 26, no. 4, pp. 123-125), published quarterly by the
New Mexico Bureau of Geology and Mineral Resources, aservice and research division of New Mexico Institute of Mining
and Technology

Internet Reference• The Union County Glacier, Jane C Love,www.geo-web.org.uk

http://www.srh.weather.gov/abq/feature/
UnionCountyGlacier2004.pdf

March 2005

Group for Earth Observation

Dear Editor,

Dear sirs,

Along with many others, I was deeply saddened to learn that
Cedric Roberts MBE had passed away. I had the privilege ofknowing Cedric for about 15 years, and have benefitedenormously from his tremendous kindness and infectious
enthusiasm. Whilst I was living locally to him in Halesowen hewas very helpful when I first tried to establish a weather satellite
station and despite me moving away around the globe we had
stayed in periodic contact ever since. Others have written afitting obituary for him, but perhaps you would allow me to sharea couple of my own experiences.

With regard your item ‘Mystery Image Censorship or Missing
Segment?’, I find it a pity that GEO is resorting to rumourmongering and submitting of conspiracy theories. I do not think
this type of item serves your readership in any way. The item
takes a probable coincidence, attempts to create a rumour andimplies a conspiracy. Where are the facts to substantiate thisclaim? Is there a known problem with the spacecraft that could
account for such ‘cutting’? What were the following images like?

One of the things that really amazed me about Cedric was his
desire to use the latest technology to help him further his
passion for weather recording and study. He was one of the firstpeople that I knew to connect to the Internet from home (using
the latest ultra-fast 28.8k modem if I remember correctly!) andoperated a fully automated electronic weather monitoring andlogging station alongside his tried and tested (manual) Met
Office standard equipment. I understand he caused quite a stirat Met Office HQ when he spotted that their standard equipment
was under-recording ‘wind run’ on days of light wind because
the weight of their anemometer propeller was ‘missing wind’ that
his smaller and lighter electronic acrylic version was recording.
One of my favourite memories of Cedric was walking around his
local area with him carrying a dipole antenna and portable
weather satellite receiver trying to locate the source of someinterference that was causing a problem with his NOAA APT
images! We weren’t successful, but I remember the looks that
we received from passing motorists!
The weather satellite community has lost an understatedstalwart in Cedric. May he rest in peace.
Ben Ramsden, Basingstoke, UK.
Dear Editor,
I only got to know Cedric Roberts in recent years, through his
use of my software, first for processing HRPT data and later for
Meteosat-8. However, if I had been at a different school in theWest Midlands during the 1960’s I might have had Cedric as
one of my teachers! As Cedric was from the same part of the
UK as myself it was always a treat to hear his voice, and hisarticles brought back fond memories. We exchanged e-mails
over recent years, but I never had the pleasure of meeting him.
I discovered that Cedric had taken a party of youngsters to
Norway in 1965, ‘well before Holidays Abroad had caught on’ as
he once wrote to me, and I gather that such visits were afrequent part of his mid-1960’s teaching activities. He was very
enthusiastic about updating his system to receive Meteosat-8
data, although his health latterly prevented him from having fulltime enjoyment of the hobby. For many years he submitted
regular weather reports to the UK Met Office, having started his
Weather Station in 1956 and it was a real treat for me to get a
copy of his Met Office report as an unexpected present one
year! He was a Fellow of the Royal Meteorological Society andan MBE (Member of the British Empire). An enthusiast andgentleman like Cedric will be sorely missed.

GEO Quarterly No 5

I am very surprised that GEO would allow this type of item to be
published.
Best regards,
David Lee

Freak Storm Ravages Paris
During the afternoon of December 17 last year, a brief but
devastating storm producing hurricane-force gusts of up to 130
km per hour swept across northern France and battered thecapital, Paris. One woman died when a tree was toppled on topof her car, many others were injured by flying debris and
385 000 homes were left without electricity. The storm also
caused major disruption to air, rail and road traffic. In all, there
were six fatalities, most caused by falling trees.
The storm hit Paris without warning and though it lasted only a
few minutes it caused havoc. Trees were shaken violently andtiles were dislodged from rooftops. The Eiffel Tower, parks andother outdoor facilities were closed. The powerful gusting winds
prompted Meteo France (the national weather service) to issue
its second highest alert and warned people not to use their cars.
The Paris fire service had to deal with thousands of calls for
help, mainly as a result of falling tiles, branches and downed
power lines
At the Château de Versailles outside the capital, tourists were
evacuated after nearby trees began to be uprooted. In
Normandy, a high motorway bridge spanning the river Seine
was closed.

The 12:49 UT synoptic chart, showing the storm centre as it starts its
journey across northern France on December 17.

David Taylor, Edinburgh.
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GEO Quarterly No 5

Group for Earth Observation

This one-meter resolution image of the Island ofStromboli, Italy near the Sicilian coast was taken by
Space Imaging’s IKONOS satellite on April 29, 2003.

The image shows impressively Stromboli, surroundedby the Tyrrhenian Sea.

The island of Stromboli belongs to the Aeolian Islandsof Italy and rises up to 3,000 m above sea level. In thesouth west the port of Ginostra, and on the other side of
the volcano the village of Stromboli, are visible.

Image: spaceimaging.com

40

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March 2005

Group for Earth Observation

GEO Quarterly No 5

these low elevation passes I just mount the antenna on a small
tripod and point it north.

John Heath G7HIAAre you missing some very interesting images from the Polar
Orbiters: NOAAs 12, 15 and 17? If you live in a built-up area theanswer is probably ‘yes’. For many of us, houses and tallbuildings prevent reception from satellites at low elevations inthe sky. Even in a rural location you may have trees, hills or
mountains in just the wrong place.
Holidays can offer an opportunity to find an open space. A
recent trip to the West Coast of Scotland gave me the chance toobtain images of the high latitudes of Greenland and the elusive
Svalbard group of islands, often obscured by cloud.
I find that a directional antenna which gives some gain is mostsuitable for this type of excursion. A three element Yagi works
well and goes in the car fully assembled. It gives around 6 dB ofgain and has a beam width of 50 degrees or more. Because of
the beam width there is no need to track the satellite and for

The illustration shows a commercial (Arrow) antenna made in
the USA and purchased from AMSAT-UK. Designed for portablesatellite work it has 2 m and 70 cm combined. Here only theelements for the 2 m band have been fitted. Although optimisedfor 146 MHz, this antenna still gives perfectly good reception
results at the satellite frequencies of 137.50 and 137.62 MHz.
With such a short cable run from the antenna to the receiversignal losses in the cable are negligible.
The receiver is my trusty RX2—battery powered. The laptop
does not need to be high spec. I use an old model scrounged
from work. It runs my favourite tracker and Wxsat for imaging. I
suggest you take a print out of pass predictions for easy
reference. You could possibly do away with the computer
entirely and record the audio on a digital tape recorder orminidisc player for processing at home later. Something I havenot tried as yet.
If you need convincing that there are some interesting images tobe had at low elevations, I hope the ones shown here willchange your mind—Happy Imaging

David Taylor

Greenland in summer - NOAA 15 visible from August 1m 1999

The portable ground station, pictured on the West Coast of Scotland

RF attenuation by Sturnus vulgaris(Common starlings photographed on David Taylor’s turnstile antenna)
Photo: Cecilia Taylor

The above image illustrates an ADL (Active Dynamic Loading)experiment in progress on a turnstile antenna for the new
NOAA-N frequencies. Variable flap-rate can compensate for
Doppler shift during the pass but you are warned not to standdirectly under the antenna for extended periods due to thedanger of contamination.
Svalbard - NOAA 17 IR at 18:49 UT on November 24, 2004

N.B. - Please don’t get your feathers ruffled about this!

www.geo-web.org.uk

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GEO Quarterly No 5

Group for Earth Observation

March 2005

Douglas Deans - douglas@dsdeans.freeserve.co.uk

As promised in my last GEO column, this quarter is dedicated tocatching up with updates to some of the software on the GEO
CDs. There are no major updates to report and most are forcosmetic or bug-fix reasons. May I remind readers that updates
to software are incorporated into the CDs progressively as they
appear. This ensures that when software is ordered andprovided it will always contain the latest program versions
available. Sometimes an update will be reviewed in the following
quarter’s magazine but often there is insufficient space to do
this, or the update is so minor that it does not justify column
space.

The updates are too numerous to catalogue here but include ahuge range of new tools providing red-eye removal and pencil
and texture brush to mention just a few. Many new special
effects have been added and there is an enhanced userinterface with re-designed tool icons and many other options.

Satscape v 2.02

And finally a first for the GEO Showcase….a program removal.
I have taken out the program e-weatherman from CD2 as it
appears to be no longer supported by Metcheck.

Satscape is a well established satellite tracking program by
Scott Hather. The recent update has a few minor fixes but thisis a program with many useful features. It is possible to open
multiple windows and have several 2D and/or 3D views on thescreen tracking different satellites simultaneously. The programis able to track up to 500 satellites at a time with various map
views, ground tracks and footprints provided. A wide range ofinteresting maps have been included with the GEO software.
There are too many options to mention in this brief outline but all
in all this is a very well presented package which, to Scott
Hather’s credit, still remains freeware.
For more information or to download the program go to :-For more information or to download the program go to :http://www.neosoftware.com

All the above programs are available on GEO Software CD,
GS2 but please note that NeoPaint is a 30 day trial version.

SOFTWARE CATALOGUE
GS1 A l l D a vi d Ta yl o r ' s w e a t he r s a t e l l i t e p r o g r a m s a ndli b ra ri e s , i nc lud i ng the c urre nt re le a s e s o f W X tra c k ,S atsi gnal, HRP T Reader, GeoS atsi gnal, GroundMap,
RX2 PassControl and many other program extras. This
disc also contains a large quantity of sample files, manyof high-resolution data, for use with these programs.
WXtrack
Satellite Tracking Program v 3.4.6
C
reates images from
SatSignal
v 4.1.0
wave files
C
o
n
v
e
r
t
s
r
a
w
H
R
P
T
d
a
t
a
HRPT Reader
v 2.5.4
files into images
M
a
n
i
p
u
l
a
t
e
s
g
e
o
s
t
a
t
i
o
n
a
r
y
GeoSatsignal
v 4.2.0
weather satellite images

http://www.satscape.co.uk

Element Manager v 1.59
Element Manager is a 32-bit program designed to manipulate
NASA and NORAD two line element sets. It will work with
Windows 95 up to XP platforms. You can import files containing
2-line elements irrespective of accompanying text; the element
sets are stripped of all extra text and only the two-line elements
themselves are saved. The main update in v 1.59 adds further
options—the Satellite Situation Report and in particular theability to read the files and export them.
For more information or to download the program go to :http://www.elementmanager.com

NeoPaint v 1.45
NeoPaint is a powerful graphics program which started life as a
DOS paint program but is now a fully featured 32-bit tool
suitable for Windows 95/98/ME/NT/2000 and XP platforms.
Some of the many new features in the Windows version include:
support for most popular image formats including JPEG, GIF,
PCX, TIFF, BMP and PNG; integrated support for scanners anddigital cameras; professional quality output to any Windows
compatible black and white or colour printer; multiple undolevels; dozens of special effects and textures; custom paintbrushes; photo retouch and colour correction tools; high quality
colour and format conversion; masking; colour separation;
Picture Browser with file management tools; built-in NeoGrab
screen capture; and dozens of other tools and options.

42

GroundMap

Rescales satellite images

v 1.3.8

RX2 PassControl

Computer control program
for the RX2 receiverv 2.2.8

GS2 A wide range of software for all aspects of weather satellite
recepti on, i ncludi ng tracki ng, recei vi ng, moni tori ng andimage manipulation. Content is detailed below but manyother extras are provi ded. Ti tles correspond wi th folder
names. * implies a DOS program.
Recall (wave file recorder), PaletteCollection D02(modifies Wxsat colour palettes).
Scanner recorder v 1.8 (wave filerecorder), *NOAA95/*FENG99
Collection D03(software for the NOAA 95 HRPT
project)
Wxsat v 2.59 (wave file
Collection D04
recorder/decoder), Satmon (wavefile recorder).
AGSatTrack
Satellite tracking program v 1.33
Documents for the Cirkit Wxsat
Cirkitreceiver and the UOSat receiver(PDF format)
Element Manager 2-line element manager v 1.59
Footprint
Satellite tracking program v 2.10
Irfan View
Image/slideshow viewer v 3.80
Evaluation version
JVcomm32(APT/FAX/SSTV decoder)Macintosh kepler Edits verbose AMSAT format
editorelements. Mac OS X and OS9 only.
Image processing program
NeoPaint(30 day evaluation)
Image processing program
Paintshop Pro(30-day evaluation)
S
atellite tracker and wave file
Satscape
recorder v 2.02
Utility program for splitting andSplitterreuniting large files
WAV file recording and decoding
WXtoImg
program with many options. v 2.5.11

www.geo-web.org.uk

March 2005

Group for Earth Observation

GS3 3DEM Package for 3D Terrain Visualisation
This CD includes the full set of GLOBE Tiles to allow you
to p ro d uc e e xc e lle nt i ma g e s a nd flyb ys fro m HRP T
inages. Also included is a selection of Mars MOLA files,
sample images and helpful guides by Ed Murashie.
GS4 Image CD
A wide selection of high-resolution remote images froma range of satellites, including stunning imagery from theSpace Shuttle missions. A full description and source ifprovided for each image.

GS5 Mars Rover Panoramics
A chronologi cal account, i n panorami c i mages, of theNASA Mars Rovers' progress across the Martian Terrain

How to Purchase CDs
Simply 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) for
the appropriate amount. Nothing else is required.
The cost includes the CD, packaging and posting, a small
donation towards the cost of overheads, the cost ofoverseas orders and the search for new or updated
software. No fee is asked from overseas members
although an exchange of software or interesting satellite
images is always welcome.

GEO Quarterly No 5

Weather Predicting Simplified
A Book Review by By Peter Bartlett

I thought readers might be interested in the following
book that I have recently acquired. Wanting a book thatwould further enhance the excellent ‘Interpreting
Weather Satellite Imagery’ articles written by Peter
Wakelin, I came across Weather Predicting Simplified, abook that also assists me with gaining a better
understanding of basic meteorological charts and weather
data, coupled with weather satellite images.
The 180-page book measures 190 x 240 mm and in myopinion will suit all readers who want to gain a better
understanding of their satellite weather images. Having
an interest also in Digital Atmosphere, I have found thatthe book has helped me gain a greater understanding of
weather movements and events.

Orders are normally dispatched on the day of receipt.

The book is laid out into eight chapters, following an
introduction which states: ‘This book is intended foreveryone interested in the weather and is meant as ahandbook to be used and referenced frequently. Although
the book’s main focus is on marine weather, it will help
anyone interested in understanding, analysing andforecasting weather’.

Order your CDs from:The chapters covered are:Douglas Deans, 17 Montrose Way,
Dunblane, Perthshire FK15 9JL, Scotland.

New Chinese Satellite
Feng Yun 2C, the first geostationary meteorological satellite wholly
designed and built by the Peoples’ Republic of China, was launchedfrom the Xichang Launch Centre on October 19, 2004. FY-2C, whosename means ‘winds and clouds’ replaces FY-2B.

The satellite has been designed to monitor the temperature and theclouds above China and neighbouring areas and will provide
meteorological information for the Asia-Pacific region.
This first visible light image was acquired on October 29.

Member’s Advertisement
For Sale
Boxed and tested HRPT RX (Sam Elsdon design) with LNA(also boxed), working very well.
Never used, except for testing because I cannot install asuitably sized dish with AZ/EL at my location. Offers please
to Dave Houlden, Portland, Dorset.

1 What Makes the Weather
2 How Weather Reports and Charts are Prepared3 Marine Coastal and Offshore Weather Forecasts
4 Surface Charts
5 Upper Air Charts and Jet Stream Systems
6 Speciality Charts
7 Satellite Images
8 Integrating Satellite Images with Weather Charts
The book is filled with predominately monochrome
drawings, charts and satellite images to assist in
predicting the weather; almost every page has some kindof visual aid. Chapter 8 contains more than one hundred
examples of weather systems and events portrayedthrough charts, text and satellite images. Although the
majority of the diagrams feature the USA, there is also a
reasonable number of examples from Europe. This does
not effect the overall aim of the book: to provide the reader
with a greater understanding of weather charts andimages.
The book rounds off with appendices headed ‘Radar’,‘Weather check-list’ and ‘Resources’ (two pages of various
Internet weather-related sites).
Overall I have found this book to be very informative anda pleasure to both read and own. It is written by Michael
William Carr and was published in 1999, in hardback, byInternational Marine. Price £15:00 (ISBN 0-07-012031-5)
Reference
Digital Atmosphere Software:e-mail: dave@g1ocn.com

http://www.weathergraphics.com
www.geo-web.org.uk

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March 2005

Fred van den Bosch
Yes! I have managed to get my MSG-1 system up andrunning: and in fact it all turned out to be rather easy.
Here are my experiences. Because Mike Stevens gave
exact details of the software installation[1] in GEO Q4, I
will only mention those points where I can add additional
information.
Installation
Installing the Skystar card did not cause any trouble. I
placed the card in my PC, inserted the accompanying
software CD and soon had everything working. The Astrasatellite was found quickly and at first I played a bit withreceiving TV stations. Then I tried to receive Hot Bird-6
but could not pick up anything! It turned out that I had
been using the position of Meteosat-8 itself in WXtrack
and this differs by about 30 degrees from Hot Bird-6.
After a hint from one of our members I tried again.
Starting from Astra, I moved the dish very carefully to theright (when you look in the direction of the satellite) andbingo—there it was! But do remember that Hot Bird-6 isvery close to Astra.

same as in GeoSatSignal—only the scale must be
adjusted. A good starting point for the scale is: multiply
the span by 90. So if the span in GeoSatSignal = 40 thenthe scale in DA = 40 x 90 = 3600. The map projection usedin GeoSatsignal is orthographic. A selection of parameters
matching Geosatsignal images with DA maps appears infigure 1.
The illustration inside the front cover of this issue showsa false colour HRV image from 29-12-04 12.00 UT, uponwhich isobars and fronts have been added using Digital
Atmosphere.
Region

GeoSatsignal

Digital Atmosphere

Meridian

Parallel

Span

Lat

Lon

Scale

Europe

5

52

40

52

5

3600

Africa

2

20

75

20

2

6420

Netherlands

5

52

4

52

5

370

N America

-95

45

40

45

-95

3600

Figure 1 - Parameter sets for linking Geosatsignal images with DA

Testing
Then came the most difficult part—waiting until theclient software and Key Unit were delivered by
EUMETSAT. The time spent waiting wasn’t wasted
however. I received copies of some raw MSG data files
from one of our members (files received directly by the
EUMETCast client software) and spent a couple of days
decoding them using David Taylor’s software. This
allowed me to completely set up MSG-DataManager. The
resulting MSG images were then used for testing
GeoSatSignal, designing the jobs and adjusting the linkwith Digital Atmosphere. All this was thanks to trial
licences [2] for MSG-DataManager and GeoSatSignal
supplied by David Taylor
Receiving
When finally the EUMETCast client software and Key
Unit were delivered the remaining part was easy.
Installation was quickly completed by following theaccompanying manual. My only mistake was failing to
add access to the tqrecv.exe program from Zone Alarm, thefirewall that I use. This resulted in a yellow ‘T’ thatobstinately refused to turn pink. When, after somesearching around I switched off Zone Alarm, the data
came streaming in. Because all the programs had alreadybeen set up correctly during the test period (while
awaiting the arrival of the Key Unit etc.), everythingworked immediately and well. All that now remained wasa little fine-tuning.
Linking with Digital Atmosphere
I explained in GEO Q2 [3] a procedure to link APT weather
satellite images with Digital Atmosphere: this is veryeasy. Linking Digital Atmosphere with MSG-1 images iseven easier. Latitude and longitude in DA are exactly the44

Figure 2 - Regions covered by the parameter sets in figure 1

SystemMy system is a 2.6 GHz computer with 512 Mb RAM. At
the moment, receiving and decoding are both done on one
system. All my other computing is done on the same PC
too, so I have ‘somewhat poorer’ response times: almost as
slow as my old 266 MHz PC!
ImagesOn the EUMETSAT home page at www.eumetsat.de you
can click on the banner ‘Meteosat-8: A New Service
Dimension’ where you will find a link to the ‘MSG
Channel Interpretation Guide’ page. There you will findsome PowerPoint presentations which describe how you
can combine several images in to a new one. There are lotsof ideas there.

www.geo-web.org.uk

March 2005

Group for Earth Observation

GEO Quarterly No 5

You can also link directly to this page using:
http://www.eumetsat.de/en/dps/msg/channel_interp/index.html

You can find more help on this theme from Arne van
Belle’s ‘MSG colour composites how-to’ guide from:http://groups.yahoo.com/group/SatSignal/files.

Finally for those who are still in doubt—I succeeded so
it is not difficult!

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

Good luck!
References
1. Meteosat-8: The Challenge - Mike Stevens, GEO Q4, page 34.
2. David Taylor is always pleased to provide trial licenses for his
software. These are valid for about three weeks, and are to berecommended. (davidtaylor@writeme.com)
3. Using WxtoImg Images in Digital Atmosphere - Fred van den
Bosch, GEO Q2 page 9

Information about the hardware required to receive Meteosat-8
and advice about registering for the various MSG services. John
will also ‘field’ any queries of a more general nature about any
aspect of receiving weather satellite transmissions.
• telephone: (0208) 390 3315
• e-mail: info@geo-web.org.uk
Keith Holland, London, ENGLAND

Appendix I - More on using Fleetwood Data Files
Last issue, Ton Lindemann explained how you can use
Digital Atmosphere to add Fleetwood synoptic data to
your Meteosat-8 images. Unfortunately, since Ton wrote
his article, the Internet address given for downloading the
Fleetwood files has become password protected. However,the files are still accessible by using the following (thefinal two characters are ‘zero’).
http://ftp.hb-yacht.ch/ASXX21.@D@S00

The ‘@D’ token picks out the current day from yourinternal PC clock while ‘@S00’ selects the ‘synoptic hour’by rounding down the time on your PC clock to 00, 06, 12
or 18: so the address above will always load the mostrecent set of Fleetwood data.
Appendix II - Analysis Scripting
Digital Atmosphere can read script files to automatecomplex procedures such as Ton’s for adding Fleetcode
overlays to current Meteosat-8 images.
The following file will collect the 12:00 Fleetcode file fromthe Internet and overlay it onto your current Meteosat-8
image. The file can be called ‘1200.dsf’ and is a text filethat can be created using any text editor. It is loaded into
Digital Atmosphere using the ‘Run’ button on the‘Scheduler’ part of the Scripting tab in the toolbox. Of
course, you will have to substitute your own folder andfilenames. You can create a file for any synoptic hour, andyou can also use the tokenised address given above.
## download and store 12:00 UT Fleetcode data ##download,http://ftp.hb-yacht.ch/ASXX21.@D1200,c:\Program
Files\DigitalAtmosphereWS\fleetdata\fleet.dat## import the Fleetcode data into Digital Atmosphere ##ingest,c:\Program Files\DigitalAtmosphereWS\fleetdata\fleet.dat## load the correct Digital Atmosphere base map ##load,c:\Program Files\DigitalAtmosphereWS\fleetwood.dmf## import the Meteosat image made by GeoSatSignal ##import,c:\Program Files\DigitalAtmosphereWS\msgmaps\met8.bmp
basemap
fleet
stamp
#

Page 45

Specifically help for APT users (137 MHz band) and Meteosat-7
wefax.
• e-mail: geo@koholland.plus.com

David Strickland, Truro, Cornwall, ENGLANDDavid has set up his own wireless network system of threecomputers. He has interests in electronic design andprototyping, general computing, microchip processors withvarious facilities and of course MSG satellite imaging. He will behappy to discuss any of the above topics, and to help anyone
local, including viewing his setup.
• e-mail: David@Strickland.uk.com
Geoff Morris GW3ATZ, Shotton, Flintshire, NE WALES
Geoff has lots of experience aerial, coax,connectors, mounting
hardware etc. Also done a lot of work with the orbiting satellites.
Geoff is know his way with most of David Taylor’s software. He
has recently started with MSG, so should be able to share his
experiences with other 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. He also runs Meteosat-7 SDUS.
• agm@tonbridge-school.org

Hector Cintron, San Juan, Puerto Rico, USA
Hector is prepared to field enquiries on HRPT, APT, WEFAX,EMWIN and NOAAPORT• Tel: 787-774-8657• e-mail: n1tkk@hwic.net

E-mail contact can of course be made at any time, but wewould ask you to restrict telephone contact to the period
7.00-9.00 pm in the evenings.

www.geo-web.org.uk

45

GEO Quarterly No 5

Group for Earth Observation

March 2005

Back Issues
If you are a recent recruit to GEO, you may beinterested to learn that you can complete yourcollection of printed GEO Quarterly magazines bypurchasing back-issues. These are available, to
GEO members only, on a unit price basis asdetailed below.

Manager: Clive Finnis
e-mail: shop@geo-web.org.uk
FAX: +44 (0) 1202 893323
GEO is pleased to offer members the opportunity to purchase
GEO-PIC 1.0, a replacement PIC for the RX2 receiver. This will
enable you to receive the two new NOAA APT frequencies thatwill be operated by the final satellites of the series, NOAA 18
and NOAA 19. NOAA 18 is due for launch in March this year,with NOAA 19 following in December 2007.

If you have recently joined GEO for the first time, we can offer a
CD with PDF versions of the four 2004 issues of the GEO
Quarterly to bring you up to date.

GEO-PIC 1.0
GEO 2004 CD

UK

EU

RoW

7.00
8.00

7.40
8.40

8.30
9.30

All prices include postage and packaging• UK• Europe• Rest of World(2nd class mail)(printed paper)(printed paper)

£3.50
£4.20
£5.10

Back-Issues Currently Available
GEO Q2
GEO Q3
GEO Q4-

May/June 2004
Aug/Sept 2004
Nov/Dec 2004

Requests for back issues should be sent to:
Nigel Evans, GEO-SUBS, Eventail, 7 Gloster
Ropewalk, Dover, Kent CT17 9ES, UK
Payment can be made by supplying your credit card
details (card number + expiry data). UK readers
can also pay by personal cheque or postal order.
Enquiries for more information can be sent tomembers@geo-web.org.uk

Launch Issue

Payment Methods• UK members may pay by personal cheque, Postal Order or
Credit Card.
• Non-UK members may pay by credit card.

We still have free copies of the GEO Launch Issue
available. If you have friends who might beinterested in learning about GEO, please encouragethem to send for their copy by completing theapplication form on the GEO website at:
http://www.geo-web.org.uk/join.html

All cheques and Postal Orders must be made payable
to “Group for Earth Observation”
VISA, Mastercard, Switch and Switch Solo are all
accepted, but please note that you must state

Weather Satellite Frequencies• the cardholder’s signature• the type of card, card number and expiry date
• the issue number (for Switch and Switch Solo only)

Polar Orbiting Satellites

All credit cards are authorised before goods are despatched

NOAA-12137.501698.0NOAA-14-1707.0NOAA-15137.501702.5

NOAA-16-

1698.0NOAA-17137.621707.0-1700.4

Please include your e-mail address or telephone number incase we need to contact you about your order. In the event ofproblems with items purchased from GEO-Shop, please contact
Clive Finnis.

Frequencies (MHz)APTFeng Yun 1C, 1D

HRPT

Ordering and Shipping
Orders should be sent to:
GEO Shop, PO Box 1375, Christchurch BH23 9AS, England
We will ship by post, so please allow a few days for items toarrive in Europe and perhaps a few weeks for the Rest of theWorld.
Items from the GEO shop are available
only to paid up GEO members

46

www.geo-web.org.uk

Geostationary
Satellites

Location

Frequencies
WEFAX (MHz)GOES-E

USA

75°W

1691.0GOES-W

USA

135°W

1691.0

Meteosat-5

INDOEX

63°E

1691.0

Meteosat-6

Europe10°E

1691.0

Meteosat-7

Europe0°1691.0, 1694.5

Meteosat-8

Europe0°

D VB

March 2005

Group for Earth Observation

GEO Quarterly No 5

Subscription Rates for 2005
United Kingdom
EuropeRest of World

-

£16
£19
£22

Subscription is valid for a period of one year
from your date of application, and will entitle
you to all the privileges of membership of theGroup for Earth Observation, including four
issues of GEO Quarterly.
Please note that your subscriptioncommences with the issue of GEO Quarterly
current at the time of your application. Backissues, where available, are advertised inyour copy of GEO Quarterly.

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for a period of one year
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47
www.geo-web.org.uk

GEO Quarterly No 5

Group for Earth Observation

March 2005

NOAA 12NOAA 15NOAA 17NOAA 12NOAA 15NOAA 17

Mar 01 05:48 07:28 15:37 17:18
Mar 02 05:23 07:03 15:13 16:53
Mar 03 04:59 06:39 14:48 16:28
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Mar 26 05:32 07:12 15:21 17:01
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Mar 30 05:33 07:13 15:23 17:03
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May 10 05:23 07:03 15:12 16:52
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May 13 05:49 07:29 15:38 17:19
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Apr 21 04:51 06:31 14:41 16:20
Apr 22 04:27 06:07 14:17 15:56
Apr 23 05:42 07:22 15:31 17:12
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Apr 25 04:53 06:33 14:43 16:22
Apr 26 04:28 06:08 14:19 15:57
Apr 27 05:44 07:24 15:33 17:13
Apr 28 05:19 06:59 15:08 16:48
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Apr 30 04:30 06:10 14:20 15:58

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

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10:27 12:07 20:17 21:56
10:04 11:44 19:55 21:33
11:21 13:01 21:11 22:52
10:58 12:38 20:48 22:28
10:35 12:15 20:26 22:05
10:12 11:52 20:03 21:42
11:30 13:10 21:19 23:00
11:07 12:47 20:57 22:37
10:44 12:24 20:34 22:14
10:21 12:01 20:12 21:51
09:58 11:38 19:50 21:28
11:15 12:56 21:05 22:46
10:53 12:33 20:43 22:23

48

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

Heinz Fischer from Immberg in Germany sent us this 12:30 UT Meteosat-8 image from October 10, 2004, showing two impressive
depressions on the same image, one over the Bay of Biscay, the other approaching over the Atlantic.
Image © EUMETSAT 2004

The main board of the RX2 receiver showing
the new PIC in place at upper right.

This photograph of a built RX2 kit in a customised case wassubmitted by Norbert Puetz from Erding in Germany.