Group for Earth Observation

The Independent Amateur Quarterly Publication for
Earth Observation and Weather Satellite Enthusiasts

37
March 2013
Inside this issue . . .
Esko Petäjä turns his
attention to earthquakes,
discussing how satellite
observations can help intheir prediction, andexplaining how an
inexpensive sensor andfree software enabled him
to participate in the Quake
Catcher Network.
In an extract from PaulWhite’s ‘Clouds Across the
Moon’, he describes someof the early days of
weather satellite imaging,when ESSA, ATS and
Nimbus were the state-ofthe-art spacecraft.
For readers with aninterest in environmental
monitoring, and who needto publish information froma database on theInternet, Andreas Lubnow
describes a project which
harnesses a Geiger
counter to add radiation
data to his existing
EUMETSAT station.
There is another article tohelp readers obtain themost out of David Taylor’s
L1 Viewer, tips on finetuning a EUMETCast
computer to handle the
new MSG-3 data, a reportfrom NASA on the current
climate warming trend andmore besides .......

GEO MANAGEMENT TEAM
Director and Public Relations
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Milford, Godalming, Surrey GU8 5AB,
England.
Tel:
01483 416 897
email: francis@geo-web.org.uk
General Information
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GEO Quarterly Editor
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email: geoeditor@geo-web.org.uk
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email: tech@geo-web.org.uk
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email: shop@geo-web.org.uk
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email: international@geo-web.org.uk
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Publisher
Published by The Group for Earth
Observation Limited, a company in Englandand Wales, limited by guarantee and nothaving share capital.
The Company Number is 4975597.
The registered office is Coturnix House,
Rake Lane, Milford, Godalming,
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Responsibility
Every effort is made to ensure that thetechnical and constructional articles
published in this Quarterly are correct.
However, the ultimate responsibility iswith the reader to ensure the safety of
constructions and for any interfacing withother equipment. GEO cannot accept liability
for shortcomings in any published design or
any constructions carried out by members orother third parties.
Copyright GEO © 2013
The contents of this Quarterly remain theintellectual property of the Group for Earth
Observation Limited and its contributors.
Copying of text or images, either from theprinted Quarterly or from any electronicallystored source, is forbidden without
permission from the Editor.

Les Hamilton
geoeditor@geo-web.org.uk

FA

irstly this quarter, apologies for two compilation errors that are rectified on page 12 ofthis issue: the omission of Robert Moore’s Falkland Islands image and some incorrect
total-ozone maps. I hope these errors did not spoil your enjoyment of the December issue.

new approach to the reception of NOAA APT imagery has made an appearance recently,
based on the use of inexpensive DVB-T digital TV/Radio USB dongles plus public domain
Software Defined Radio (SDR) software. Rob Alblas has kindly translated and updated hisarticle, which originally appeared in De Kunstmaan, for GEO. There are also a number of videos
on YouTube that show the technique in action, and the URL below makes use of precisely thesame set-up that Rob describes. The image is seen building up on the PC monitor and really
looks to be of excellent quality. Of course, for users in the UK, there must be the caveat thatpagers could be a problem, but the cost involved is so miniscule that we hope many readers willtake up the challenge and let us hear about their experiences.
http://www.youtube.com/watch?v=o7bKsPYfOhg

W

e are fortunate in having three major feature articles this issue, from Andreas Lubnow,
Esko Petäjä and Paul White. Don’t be put off by the unusual title of Andreas’ essay. The
radiation data aspect simply relates to a currently ongoing project, and the main thrust of thearticle actually deals with a topic that should prove useful to many GEO readers: how to publish
data from environmental monitoring stations (including EUMETCast and Weather Stations) on
the Internet. Some aspects of this, such as the use of MRTG, will already be familiar to some ofyou. Esko’s article discusses the topic of earthquakes and their possible prediction from satellite
evidence, and also includes details of a project he has undertaken—joining the QC-Network via
an inexpensive earthquake sensor and free software. Paul’s submission is a modified extractfrom his e-book ‘Clouds Across the Moon’, and deals with the early days of weather satellite
imaging, specifically from the ATS, ESSA and Nimbus orbiters.

Areminder to everyone that this is the second issue during which Rob Denton is running his
Farthest West imaging challenge (see page 33 of the December Quarterly), with a prize forthe best entry. The closing date for sending your images to Rob has been revised to April 20, to
get them in before the copy deadline for the next issue.

F

inally, please note that the copy deadline for GEO Quarterly 38 is a little earlier than usual,
Saturday, April 27, 2013. This is because many contributors tend not to submit copy till thevery last minute (often past the deadline), leaving me with a mad rush to publish the magazine
on time. As I am on holiday for much of the month of May, it is essential to receive all the copy
in good time. My December Quarterly reached me only two days before the Christmas holiday,
and I suspect some readers may have had to wait even longer for theirs. The copy deadline
is intended for important last minute news, and major articles, specially those with diagrams,
images and photographs, really should be submitted at least two weeks earlier.

Contents
GEO Report
GEO Shop’s new APT Antenna
Fine-Tune your Software to Receive MSG-3
David Taylor’s MODIS L1 Viewer
Direct Reception of Metop-A Imagery
A Low-Cost APT Receiver Based on SDR
Adding Radiation Data to your Monitoring Station
NOAA Finds Long Term Climate Warming Trend
Earthquake Monitoring and Prediction
The Early Years of Satellite Meteorology
Book Review: Paul White’s Clouds Across the Moon

Francis Bell
Francis BellDavid Taylor
Alan Banks
Gordy Mas
Rob Alblas
Andreas Lubnow
A Science@NASA Report
Esko Petäjä
Paul WhiteLes Hamilton

Sea Ice Skylights Spur Phytoplankton Blooms
Comparing the Winds of Sandy and Katrina
Fires Across Cape York Peninsula
Sea Ice Retreats in the Northwest Passage
Auroras light up the Antarctic Night
Retreat of the Antarctic Peninsula’s Crane GlacierFeedback: Members Letters
Satellite Status
Sich-2 Showcase (Hoover Dam and Antarctica)
GEO Helplines and Internet Discussion Groups
Copy deadline for the next issue of GEO Quarterly
GEO Membership Application FormGEO Shop Catalogue and Price List

NASA Earth Observatory
NASA Earth Observatory
NASA Earth Observatory
NASA Earth Observatory
NASA Earth Observatory
Les Hamilton

Dniprokosmos

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17
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GEO Quarterly No 37

The Group for Earth Observation

March 2013

Francis BellI notice that in the first paragraph of my report in
GEO Quarterly 36, I offered congratulations to EUMETSAT
and ESA for the successful launches of MSG-3 and Metop-B
in 2012. Now, further congratulations are in order because of
the successful commissioning of each satellite, and as best I
can judge from reports, all the instruments and systems areworking perfectly.
I do follow daily the bulletins published by EUMETSAT andknew approximately when MSG-3 (Meteosat-10) was to enter
service as the primary satellite at zero longitude. However, I
am slightly embarrassed to admit that, in late January, I was
mystified as to why I could not display images from MSG-3. I
operate two systems, and both behaved in the same way: thatis, they displayed relayed images from GOES-E, GOES-W andother satellites, but images from zero longitude were missing.
I contacted David Taylor, the author of my decoding software,and he instantly identified the problem: my software wasstill configured for MSG-2 reception. A simple change in the‘set up’ menu—switching from MSG-2 to MSG-3—instantly
resolved the problem and I am now receiving beautiful images
from this new Earth observation satellite. There is an article
from David Taylor on page 5 to help others who may be
experiencing the same problem as I did.
Meetings
During a recent GEO Management Team meeting, we
discussed possible dates and venues for our next symposium.
For several years, we have held very successful events at
the National Space Centre (NSC) Leicester. This venue has
proved attractive because of its central location, the meeting
facilities which it provides plus the bonus of access to theexhibitions areas. However, we have to recognise that, inrecent years, there has been a decline in the numbers ofmembers attending our symposiums and this is compoundedby an increase in the cost of hiring the facilities at the NSC.
Our meeting discussed the issues without taking a specificdecision relating to a symposium in 2013. However, we did
decide to research other potential venues and, if a decision istaken, details will be published in GEO Quarterly and on our
website.
Other possible visits in mind are to the National Oceanography
Centre and/or Astrium, both in Portsmouth. Each of these isbeing researched, and again, plenty of notice will be given tomembers of times and dates.
Director’s Workload
During our annual management meeting in November
2012, I indicated that I wished to reduce some of my GEO
responsibilities and consequent workload . I have agreed to list
some of the tasks which I think could usefully be undertaken
by others, and the management team will try to progress somedegree of devolution. This is an invitation: if you think you havethe time and inclination to contribute to the running of GEO in,
say, financial matters, organising meetings or other day-to-day
matters, please contact me or another member of the GEO
management team.
EUMETSAT Book
I still have a small number of copies of the book documenting

EUMETSAT’s first 25 years. If you would like a copy, pleasecontact me directly by email at
francis@geo-web.org.uk
The book is free but you will have to pay the carriage andpacking charge for this weighty 1.8 Kg book.
Turnstile Antenna
In November 2012, I was very pleased to be able to test a
new turnstile antenna specially designed for APT reception
and manufactured for GEO by Sandpiper Aerials. My tests
related to the successful reception of NOAAs 15, 18 and19 signals. A further report appears on the next page. It isparticularly important to have this antenna available to GEO
members because the QFH antenna which we formerly
offered for sale is no-longer available.
Downconverter
A few week ago, I was contacted by a member in the USA
who was looking for a downconverter taking 1.6 GHz to
137.5 MHz. He wanted it as part of a project to establish an
HRPT receiving station. It so happened I had exactly what hewanted because these downconverters were in common use
in the early days of Meteosat reception. The downconverter
was duly shipped to the USA and, after minute examination
by US customs, was delivered to our member. In due course
I hope we can have a report about this project. The lesson
here is that if you still have a downconverter tucked away inyour shack, you should look after it; someone may have aworthwhile use for it in the future.
Volcanoes
Although it is not too late to submit your entry, I have so
far not received any members’ images of volcanoes. The
invitation to submit an image of a volcano was issued lastyear so, if you have something which you think may be worth
publication, please send it to myself of our editor. We willkeep this invitation open for the rest of 2013.
Subscriptions
Members will have noticed that we increased our subscription
rates from December 2012, something over which we had
little control because of the sharp increase in postage rates.
Printing costs have been moderately stable for several years
but we cannot escape the increases in postage and carriage
charges. Nearly all our subscription income is spent on
printing and postage, only a tiny amount being used to coverother overheads. I hope the increase in subscriptions will notcompromise any member’s decision to remain supportive of
our group.
Electronic Membership
We are actively researching a form of electronic membershipto our group. Details will be made available as soon as adecision has been made and appropriate systems are inplace.
Forthcoming Events
April 21, 2013
The West London Radio and Computer Show. This show is held at
Kempton, and GEO will have our usual stand there.
continued on page 44

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March 2013

The Group for Earth Observation

GEO Quarterly No 37

Cover and Full Page Images
Front CoverQuarterly Question 35
Quarterly Question 35 asked about theorbital altitude of Europe’s polar orbiting
weather satellite Metop-B, launchedin 2012 and now operational. When I
posed the question, the answer I had
in mind was 817 kilometres, the figure
published on both the EUMETSAT
and ESA websites. My thanks to thefollowing members who took an interestin the question and submitted correct
answers: Elmar Bogels (Brunssun,
The Netherlands), Adrian Chamberlain(Coventry, UK) and Pete Bently (UK).
All quoted a figure of 817 km or a figure
acceptable close to it.
There are several parameters to beconsidered when quoting a single
figure average for an orbital altitude.
The orbit may be slightly elliptical, so
its instantaneous altitude will dependon the reference position on Earth’s
surface from where it is measured. The
Earth is not a perfect sphere because its
rotation makes it slightly oblate, and thus
flattened at the poles. Earth’s radius
is 6,378.2 km at the equator but only
6,357.8 km at the poles, a difference of
21.4 km. Hence the altitude of a satellite,
even one in a hypothetical perfectly
circular orbit, would vary from any
quoted mean orbital altitude for different
locations on the Earth.
Quarterly Question 36
This question was prompted by theanswer to Quarterly Question 35.
Just out of curiosity, I wondered how
many times further away geostationary
satellites are compared with low
earth orbiting satellites. I did thecalculation and the scale of the answer
surprised me: that is just how far awaygeostationary satellites are from thesurface of the Earth. A geostationary
orbit is perfect for a telecommunications
satellite but a compromise for a satellitethat images or monitors the surface of
the Earth: however, the distance from
Earth’s surface for the latter is absolutely
dictated by the orbital dynamics for thisfavoured position.
Question 36 is: ‘How many time further
away from the surface of the Earthis a geostationary Earth observation
satellite such as Meteosat-10 comparedwith a low Earth orbiting satellite like
Metop-B’. To calculate the answer divide
the altitude of the geostationary orbit
by 817 and quote the answer to thenearest whole number with no decimal
places. I will accept answers plus orminus one, when compared with my own
calculation.
Here is a second less serious
mathematical question prompted by
the author Douglas Adams and his
publication: A Hitchhiker’s Guide to
the Galaxy’, which gave the answer
to ‘The Ultimate Question of Life theUniverse, and Everything’. Numerically,
the answer to this question in the storyis the same as the question relating theratio of altitude for a low earth orbiting
satellite compared with a geostationary
one. This secondary question is:
What is the name of the computer in thestory, which generated the answer tothis ultimate question?’ Just a two word
answer will be correct.
Answers should be submitted to Francis
Bell atfrancis@geo-web.org.uk

before April 27, 2013, the copy deadline
for GEO Quarterly 37.

Alan Banks sent in this Metop-A image showing
Super Typhoon Bopha as it bore down upon thePhilippines on December 3, 2012.
Image © EUMETSAT 2012

Inside Front CoverThis November 13, 2012 MODIS image
from NASA’s Terra satellite includes Zambia,
Mozambique and Tanzania, and highlights someof the lakes of East Africa’s Rift Valley: from
north to south, lakes Victoria, Tanganyika andMalawi. To the southwest are two artificial lakes(reservoirs): Kariba (far left), the world’s largest
artificial lake, and Cahora Bassa (centre).
Image: LANCE-MODIS/NASA/GSFC

Inside Back Cover
Paying homage to ESA’s Envisat mission,
Francis Breame sent us these two superb
examples of the satellite’s output: a detail ofwest Africa including Gambia and GuineaBissau, with their rivers showing prominently(top); and another of Sudan, highlighting theconfluence of the White Nile with the Blue Nile(bottom).
Image: ESA

Back CoverThis is the first image from the recently launched
Metop-B to be sent in by a reader. Mike Stevens
was impressed by this picture of New Zealandacquired from the 21:04 UT pass on February 1, anddownloaded via his EUMETCast system.
Image © EUMETSAT 2013

Page 10
This November 12, 2012 MODIS image fromNASA’s Terra satellite shows almost the wholeof Argentina, remarkably free from cloud, from
Rio de la Plata all the way south to Tierra delFuego. The River Negro is a prominent feature,
flowing eastward from the confluence of its two
tributaries, the Limay and the Neuquén. The
Negro is an important source of hydro-electricity,and its waters irrigate the province’s apple andpear orchards.
Image: LANCE-MODIS/NASA/GSFCGEO Shop’s new APT Antenna
For the past year or so, the GEO Shop has been unable to supply new turnstile
antennas for the reception of APT signals. Happily, this shortcoming has now been
resolved with the availability of a brand new APT antenna manufactured for us by
Sandpiper Aerial Technology Ltd of Aberdare, Mid Glamorgan.
http://www.sandpiperaerials.co.uk/

Discussions resulted in an agreement to produce a prototype for GEO to test. If thisproved successful, they would produce batches for us as required. I collected theprototype at November’s Kempton Radio Rally and, a few days, later tested it at myhome in Surrey.
During my tests, the antenna was mounted on a modest supporting mast, justoutside my front door, at a little above head height. I did, of course, ensure thatthe coax connections were in accordance with the supplied diagram. This has tobe correct because of the right hand circular polarisation of the incoming signal,and simply involved the connection of a short loop of coax, in addition to the coax
downlead to my receiver. Satellite signals were fed into my RX2 receiver, in turnconnected to a laptop computer running WXtoImg capture and display software. The
image below came from a NOAA-19 pass on November 30.

Page 23
This is a Terra MODIS channel-2, 250-metre
resolution image dating from January 16, 2012,
showing part of England and The Netherlandsin the embrace of snow and ice as winter’sharshest weather arrived, driven by highpressure over the Continent.
Image: NASA/GSFC LAADS Web
Processing: David Taylor’s MODIS L1 Viewer

Page 25
Mike Stevens submitted this Metop-A image
which captures the transition of the UK and
Netherlands out of January’s two-week spell offreezing weather. Much of Scotland, Englandand The Netherlands are covered by snow inthis midday image from Metop-A on January 26,
but the advancing Atlantic depression effected a
rapid thaw that cleared most of the snow within
48 hours.
Image © EUMETSAT 2013

continued on page 4

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GEO Quarterly No 37

The Group for Earth Observation

March 2013

I started receiving a worthwhile signal
almost immediately that NOAA-19 cleared
my southern horizon and, considering therather unfavourable location of the antenna(my house was partly blocking the northernhorizon), I thought this was great. Above asatellite elevation of about 30°, my signal
meter gave a full scale deflection. It’s also
worth noting that I did not use a mastheadpreamplifier and that the coax run to thereceiver was about 15 metres. I judged
the antenna to be well manufactured andeasy to assemble: it should be a valuable
resource for anyone wishing to start APT
reception or upgrade an existing system.
Turnstile of QFH?
It is no secret that I have long preferred theturnstile antenna to the QFH (Quadrifilar
Helical antenna). I accept the attraction of
the latter for its superior gain for signals
from close to the horizon, however with a
trade-off of less gain from high elevation
signals. Cosmetically, a QFH antenna mylook good and will be robust in exposed or
maritime conditions, but personally, I find it
almost impossible to believe that a QFH will
outperform a well constructed turnstile.
But what are your views? I invite anyone
in the world to test a QFH antenna against
a well located, well designed turnstile
antenna, for RF performance, and hope thatyou will send your reports and comments to

The prototype GEO APT antenna on test in Francis
Bell’s front gardenThis NOAA-19 image was received at about 13:00
UT on November 30, 2012.

the Editor, for the benefit of all our readers.

Any reader wishing to purchase the newturnstile antenna can find details on the
GEO Shop page of our website, and on
the advertisement on the back cover of thisissue. Also note that the WXtoImg softwarefor decoding APT signals is freely availableat

It is not known how long APT reception willremain available: it may last for ten years;
it could end tomorrow. NOAA-19 is the lastof the American APT satellites, and LRIT isnow the universal standard that has takenover from the obsolescent APT format
which we have enjoyed receiving for about
40 years.

http://www.wxtoimg.com/downloads/

Receiving a NOAA-18 signal with a USB Dongle and SDR Software
Turn to page 14 for Rob Alblas’ full Article

The image below shows SDR# playing apreviously recorded NOAA-18 signal at thesame time as the image is being decoded
by WXtoImg. Despite the very low signal
level, the switch between the VIS and IR
channels is clearly seen in the ‘waterfall’ as
the pattern is alternately wide and narrow.

At top left on the screen, the input device
can be chosen, e.g. the USB receiver or,in this case, an input wav file. The Centre
frequency is grayed out, but the processing
frequency can still be chosen for thisrecording. At the bottom of the screen is therecording pane, with recording selectors for

Baseband (the digitised signal before any
SDR processing) and Audio.
Recording is off in this example because
the signal comes from a prerecorded
satellite pass.
This is version v1.0.0.1000 of SDR#.

A NOAA 18 signal, received on a USB Dongle, being decoded with SDR# software - Read Rob Alblas’ Article on page 14.

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March 2013

The Group for Earth Observation

GEO Quarterly No 37

David Taylor
Meteosat-10 (MSG-3) came on stream
as EUMETSAT’s prime operational
geostationary weather satellite on
January 21 this year, replacing
Meteosat-9 (MSG-2). As far as your
SkyStar DVB and TelliCast client
settings are concerned, there is noneed to change anything. However,adjustments do have to be made to
MSG Data Manager to receive data fromthis new satellite, as outlined below.
You must first stop MSG Data Manager
processing by pressing the button withthe bright green LED, at the lower left
on the screen, marked ‘Stop’.
Now go to the Setup tab (figure 1), open
its Channel Selection tab and than the
FSD tab, to make the following checks
and changes. Ensure that Generic naming
is checked then click the ‘Advanced’
button at the lower right of the screen
to enter the Advanced Setup tab, where you
must select ‘MSG-3’ from the Satellite
drop-down selector (figure 2).

Figure 1 - The main MSG Data Manager screen highlighting the the ‘Setup’ tab and ‘Advanced’ button.

Figure 2 - The Satellite selector menu

After changing the satellite, you will
see a message panel which advises
you that a program restart is required
after you leave the Advanced Setup
screen (figure 3). Acknowledge themessage with a click on ‘OK’. Ensurethat Delete other below the Satellite dropdown selector is not checked and close
the Advanced Setup tab by clicking ‘OK’
(figure 4).

Finally, if MSG Data Manager is stillrunning, stop it with the ‘Stop’ button
then press the ‘Close’ button to exit.

If you are running the MSG Animator
software, you should close and restartthat program as well.

Next time you run MSG Data Manager,
your changes will have taken effect andyou should receive Meteosat-10 (MSG-3)
data.
As a final check, open the Logs tab,where the window should display amessage like:‘Program V2.6.8.1069 start on MSG-3’

to confirm that the MSG-3 satellite has
indeed been selected. Now press the‘Start’ button. There may be a shortdelay if you have a backlog of the new
MSG-3 data to process.

Figure 3 - The reminder message panel

The intention in the MSG Data Manager
settings is that source data other thanMSG-3 will not be deleted, and that FSD
labelled MSG1, MSG2, MSG3 or MSG4
will all be accepted and processed.

www.geo-web.org.uk

Figure 4 - Exiting the Advanced Setup Tab

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GEO Quarterly No 37

The Group for Earth Observation

March 2013

Alan Banks
MODIS Satellites - Terra and Aqua
The Moderate Resolution Imaging Spectroradiometer (MODIS)
is a key instrument aboard NASA’s Terra (EOS AM) and Aqua
(EOS PM) satellites. Terra’s orbit around the Earth is timed
so that it passes from north to south across the equatorin the morning, while Aqua passes south to north over theequator in the afternoon.
The MODIS instrument has a viewing swath width of
2,330 km and views the entire surface of the Earth every one
to two days. Its detectors measure 36 spectral bands between
0.405 and 14.385 μm, and it acquires data at three spatial
resolutions: 250 metres, 500 metres, and 1 kilometre.
Data is accessible from:• EUMETCast• the LAADS Website• the Modis Rapid Response website (near real time
images)LAADS Web is NASA’s web interface to the Level-1 andAtmosphere Archive and Distribution System (LAADS). The
mission of LAADS is to provide quick and easy access to
MODIS Level-1, Atmosphere and Land data products. LAADSWeb allows you to:• Search, order, and download MODIS products.
• Visually browse MODIS products.
• Access tools to use with MODIS products.
• Get help, including tutorials and contact information.
Of the MODIS instrument’s 36 channels, one can access allof them at 1 km resolution via the LAADS website. Fewerchannels are available at the higher spatial resolutions.
EUMETSAT’s EUMETCast Dissemination Service
In addition to the established data delivered for some years(Meteosats, Foreign Satellite Data, NOAA Regional AVHRR
and Metop Global AVHRR), the EUMETCast service now
delivers registered users with 18 channels of 1-km resolution
raw MODIS L1 data covering Europe and the Arctic Ocean.
The MODIS L1 Viewer
This program from David Taylor allows one to visualise image
or fire data from raw MODIS L1 files, acquired either fromthe Internet or EUMETCast. The data is delivered in 5-minutesegments, in HDF format, and the software allows you to
combine multiple 5-minute segments from the same pass intoa larger image. Both the raw data, and several derived falsecolour images are available.
From version 3 and upwards of the MODIS L1 Viewer, you
can process all three resolutions (250 m, 500 m or 1 km)of data from the LAADS website, and produce false-colour
combinations from visible or infra red bands.
Installing the L1 Viewer Program
MODIS L1 Viewer can be downloaded from David Taylor’s
website at
http://www.satsignal.eu/software/modis-L1-viewer.html

as a ZIP file. David recommends that the program is notinstalled in Windows ‘Program Files’ folder, especially if you
use Vista or Windows-7. Instead, create a new folder such as
C:\David_Taylor\ and extract the zipped file into this. The
extracted files include ModisL1viewer.exe, along with several
language files and dll files.

6

Figure 1 - MODIS segments displayed in the L1 Viewer

If this is the first time you have used any of David Taylor’s
software packages, you must also download and install his
Runtimes Library file fromhttp://www.satsignal.eu/software/runtimes-setup.100.zip

The extracted file will be runtimes-setup.exe, which isinstalled simply by double-clicking it.
Additionally, you should download cities.dat and countries.
dat files from the following URLs and extract their contents
into the ModisL1Viewer folder.
http://www.satsignal.eu/software/cities.zip
http://www.satsignal.eu/software/countries.zip

Finally, it would be useful to create a shortcut to theModisL1viewer.exe file on your PC’s desktop.
Using the Program
If you intend to use the program for MODIS data downloaded
via EUMETCast, you will need to be running at least one
instance of David Taylor’s MSG Data Manager software. Thisis the program that manages the MODIS-L1 data received
by the EUMETCast software and stores it in the following
subfolders
MSG-1\Images\MODIS-L1\ andMSG-1\Images\Fire\.
However, the program can be used on its own if you intend touse it for MODIS data downloaded over the Internet from the
LAADS website.
The first thing you have to do when running MODIS L1 Viewer
is to set up the program for operation by making adjustments
to parameters in the Setup tab (figure 2). You will find the
button to open this tab at the top right of the opening screen,
shown in figure 1.
These include some basic housekeeping operations suchas using the Program Control ‘Browse’ buttons to navigate to
the folders where MSG Data Manager stores the MODIS L1
images, and the Fire Images. Once done, these locations
are retained by the software for future use. This applies to
EUMETCast data. For all data sources, you must to make a

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Figure 2 - The ‘Raw Images’ tab

Figure 5 - A result obtained with the ‘User’ RGB option

Figure 3 - The classic RGB composite colour image

Figure 6 - The Vegetation, Air Mass, Ash and Dust option

Figure 4 - An RGB image created by combining channels 5, 2 and 1.

Figure 7 - The Ash Plume from the Eyjafjallajkull Volcano

similar adjustment in the Save Files panel to point to the folder
where the processed images are to be saved, and select fromthe Image save format drop-down menu the format in which you
wish your images to be saved.

EUMETCast only makes 18 of the 36 MODIS channels
available so, if you are using EUMETCast files, select
EUMETCast channels. If you are using files obtained fromLAADS Web, or a combination of both sources, you should
select All channels. The effect of this is to display either 18 or 36
buttons at the top of the Raw Images tab. This selection can bechanged at any time, but will require a program restart.

Depending on the source of your MODIS L1 files, you mustselect one of the radio buttons in the Channel Group panel.

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segment. You can select either a single segment, or a set ofadjacent segments, to be processed. How long one retains
data from EUMETCast is down to the individual: I keep minefor two weeks.
Decide which satellite to use by selecting either the Aqua or
Terra tab. You can now display any image segment by doubleclicking its outline on the browser, when it will be displayedin the Raw Images tab. Here you can review each of the 18/36
MODIS channels by clicking on the buttons at the top of thescreen (figure 2). The GEO button displays the location of theimage you are viewing over a map.
You can also display an image consisting of a series ofadjacent MODIS segments joined together. Left-click once oneach segment outline shown on the browser, followed by aright-click, then choose open multiple to display the result. For
data downloaded from the Internet, you can drag-and-drop afile from Windows Explorer on to the Browser tab.
Figure 8 - The Setup Tab

There are further selections you can make on the Setup tab(figure 8). These include Defrag Raw Data, which reduces the
pixelation at the edges of MODIS images; Stretch visible andStretch thermal, which are effectively brightness controls; Blackhot, which most prefer to use; and User RGB, which provides
some ten options where you can define which channels will
be mapped on to red, green and blue for creating colour
composite images.
Region Settings is a drop-down menu where you can select theareas for remapping the final images, e.g. ‘Europe’, ‘UK’,‘Iceland’. For now select Scale as 1 km, although you would
normally select a value matching the resolution of the raw
data downloaded from the Internet or EUMETCast.
Finally, there are the Boundary and City choices. For now, use
the Coarse Boundary Browse button to navigate to the folder
containing the countries.dat file. The drop-down box City list
allows you to select from files of city location data (such as
cities.dat) placed in the Modis L1 folder.
Setting up the Browser
On opening MODIS L1 Viewer, you are presented with theBrowser tab, which provides a graphical view of the data
available for a particular date (figure 1). There are a numberof tick boxes on the right hand side of this tab to tailor thebrowser display to your particular requirements.
Either Ascending or Descending (or both) must be selected.
My Regions highlights the preselected regions in a colour of
your choice; Coverage outlines the overall extent of the data
available, outlined in yellow; World View replaces the default
view of Earth looking down on the North Pole, as illustrated
in figure 1, with an equatorial view. If the Scan on startup tickbox has been selected, the program will check to see what
data are available in the source directory and display them.
You can refresh this by clicking on the Today button.
You can navigate through the data stored on your PC by useof the calendar control. Today displays the current day’s data,
and you can step the display backwards and forwards a day
at a time by means of the next/previous arrow buttons below
the calendar. Finally, the three palette buttons below thecalendar allow you to select different colours for ascending
and descending passes, and for region outlines.
Using the Browser
The location of each MODIS image segment that has been
downloaded is indicated on the browser map by a coloured
rectangle. In figure 1, the ascending and descending pass
images are differentiated by colour, pink and blue, eachconveniently labelled with the acquisition time of the

A right-click on the displayed image reveals a pop-up menu
offering options to add country boundaries and coordinate
grid to the image, zoom in/out, adjust the visible channelbrightness, remap to a different region and Save the image.
Other options will be variously greyed out, depending on whatis available for a particular channel/image.
What can be achieved with all this data has yet to be fully
explored by software users. Although the spatial resolution
available via EUMETCast is the same as EUMETSAT’s Metopsatellites, more spectral channels are available. The questionis whether by combining channels in different ways, one canshow detail not available elsewhere?
The availability of higher resolution 500 m and 250 m datafrom the Internet (see below) allows the user greater detail.
NOAA, in their published images, tend to go for photorealism.
This software allows users to explore different channel
combinations in producing false colour images. David Taylor
has already provided some channel combinations for users,
taken from some of his other software, to produce image
colours many will be familiar with.
Composite Images
On opening the Derived Images tab, you are presented with anumber of options for combining different MODIS channel
images into colour composites, to highlight features. The
results of some of these are illustrated in figures 3-6.
• RGB Classic(figure 3)• RGB – 521(figure 4)• User RGB(figure 5)• Vegetation, Air Mass, Ash and Dust
(figure 6)
In the user RGB tab, a right-click menu allows you to
substitute any of the ten user RGB settings you may havedefined. The Ash setting is useful for highlighting a volcanic
ash plume, like those from Iceland’s Eyjafjallajkull volcano,which caused air traffic chaos in April and May 2012
(figure 7).
Level 1 and Atmosphere Archive and Distribution CenterIf you are not a EUMETCast user, you can still enjoy theexperience of creating MODIS images in the L1 Viewer
because NASA makes MODIS data (from both the Terra
and Aqua satellites) available from the LAADS website. The
LAADS website offers a huge number of files in HDF5 format,
with resolutions down to the 250 m level. However, you doneed to be quite selective in choosing an area of interest as
each HDF5 datafile is very sizeable, generally of the orderof 150-180 MB. The files can be retrieved from an ftp serverusing a standard ftp client.
To order MODIS files, you must first visit
http://ladsweb.nascom.nasa.gov/data/search.html
Concluded on page 13

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Figure 9 - Selecting MODIS HDF5 files from the LAADS Website

Figure 10 - A MODIS image showing England and Wales almost totally cloud-free

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The Group for Earth Observation

Jordi Mas - EA3 AGY

GEO Quarterly No 37

email: jordimas@smc.es

Jordi Mas from Barcelona has been receiving Metop-A imagery directly from the satellite, andthought GEO readers might be interested to see his results.
Jordi writes:
Figure 1 shows part of an image I received from a Metop A pass on December 1, 2012.
Information about the design of my demodulator equipment and the capture software I used canbe found on the website of my friend Oleg, at
http://sat.cc.ua/index.html

Figure 2

The reception system consists of a
• 1.2 m parabolic dish antenna• modified Kuhne convertor• 3-cavity bandpass filter• Comtech SLM-7650 modem demodulator• Yaesu G-5500 rotator• ERC-M interface• WxTrack and HRPT Reader from David Taylor.
The display in figure 2 shows the reception of the AHRPT signal, and figure 3 shows thedemodulator in operation.

Figure 3

Figure 1 - Part of a Metop-A pass received by direct reception of the satellite’s AHRPT signal, on December 1, 2012.

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These are the four total-ozone maps that should have accompanied the article on page 18 of GEO Quarterly 36

This is the Terra MODIS image from Robert Moore that failed to make an appearance in our previous
issue. Acquired on January 10, 2012, the Falkland Islands are prominent in the south Atlantic ocean.
Image © EUMETSAT 201212www.geo-web.org.uk

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GEO Quarterly No 37

David Taylor’s MODIS L1 Viewer
Continued from page 8

where the process is fairly straightforward, making choicesfrom a series of drop-down menus as follows:• Select Satellite: Terra (or Aqua) MODIS• Select Group: Terra (or Aqua) Level 1 Products• Next click on one of the following three options:• MOD021KM (1 km resolution)• MOD02HKM (500 m resolution)• MOD02QKM (250 m resolution)• Select Temporal Type: This can be either a range of dates (USFormat) or just a single day. To avoid too many choices, keep
to a narrow range. Note that the current day’s images are notavailable.
• Select Collection: Choose item No. 5(Modis Collection 5 - L1, Atmos and Land)• Spatial Selection: This is best done by selecting latitude/
longitude and drawing a rectangle on the map of the worldthat appears.
• Coverage Selection: I choose ‘Day’.
• Metadata – ignore this item - I’ve never used it.
• Saved Parameters: this section allows you to save yourcurrent search parameters (or load a set already saved), sothat you can download files for the same set of parametersagain with minimum effort - a useful shortcut.
• Press ‘search’.
A new window now opens showing all the passes that areavailable (figure 9). A quick browse RGB selector to the rightof each entry lets you view any image before you download it.
Since all files are selected by default, you really need to click
the Clear all Checkboxes button first and select only the image
files that you want. File sizes are given.
• Click the Order files now button at the foot of the page.
A new page appears where you are asked to enter an e-mailaddress. The location of your selection of files will be sent toyou in an email.
• Select Delivery Method: ‘FTP pull’ is the option to use.
Now, click the Order button and await confirmation notifying
you that your files are ready. This generally takes no longer
than a minute or so, and a new screen pops up containing
the Order Id link. Click this to learn details for retrieving
your files. You will also receive an email with the same

information, which includes the name of the folder where
your selection of files can be found, and also, importantly,
the parameters you need to enter into your FTP client.
Viewing HDF5 Files in the L2-Viewer
There are two ways to load HDF5 files into the L1-Viewer. If
you have downloaded a folder of several MODIS segments,
use the File / Browse directory option. The result will be identicalwith what has been described above for EUMETCast-derived
MODIS images (figure 1), and you can select from the screen
either a single image or a selection of images for joining.
Note: MODIS L1-Viewer will only load folders of 1-kilometre
HDF5 files in this manner. Author David Taylor confirms
this, stating that computers would not be able to cope withthe sheer bulk of 500 m and 250 m files. However, individual
high-resolution files can be loaded by means of the File / OpenL1 file option.
Conclusion
This is another excellent program from David Taylor, which
I find an invaluable extra tool in visualising the Earth. It isin constant development, and registered users have accessto the author and other users through the SatSignal YAHOOGroup athttp://tech.groups.yahoo.com/group/SatSignal/

The MODIS L1 Viewer gives excellent results, even with
the EUMETCast 1 km MODIS images, which seem to me
to be slightly better than Metop ones. And of course, theimages produced from the higher resolution MODIS data areoutstanding, and to me well worth the cost of the software.
Figure 10 shows a typical MODIS high-resolution image of aparticularly cloud-free England.
I have recently explored combining data of different spatial
resolutions to achieve an RGB image at 250 m. To do thisone has to take the two 250 m channels from LAADS (onlychannels 1 and 2 are available at this resolution) alongwith an additional channel at 500 m or 1 km, also fromLAADS. Other users are experimenting with the program andreporting back via the SatSignal Yahoo Group. This allows
David Taylor to respond to users’ ideas and suggestions forfurther software development.

This Channel-2 Aqua/MODIS image from the LAADS website shows a series of vortices west of the Cape Verde Islands on January 8, 2013
Image: NASA/GSFC

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Rob Alblas
This article was first published in the September 2012 issue of ‘De Kunstmaan’,and has been translated and updated for GEO by the author.
Up to some time ago, receivers were built purely withhardware: preamplifier, IF with a certain bandwidth anddemodulators (AM, FM, single-sideband etc.) were designed
and built for a specific application. These manipulations canalso be described in mathematical formulas, and therefore
they can be calculated by a computer. This must be done
real-time, so a lot of calculation power is needed.
With present-day computers, it is possible to design a
Software Defined Receiver (SDR), which is based on software
instead of on hardware. The advantage of a software-receiveris that it is much more flexible; a disadvantage is that afast computer is needed, which must not spend too much
power in other applications. The calculations must continuesmoothly; a short stop because, for example, Windows finds
it necessary to download a program update from the Internet,
may give problems. There is a little bit of timing-flexibility
in the calculation process. If a fixed delay during signal
processing is no problem, then results of calculations can bebuffered so that, if the calculation stops for a moment, an
output signal can still be provided from the buffer.
A software receiver, of course, needs an antenna signal,
which first must be amplified to a certain level. Also,
digitising and processing a 137 MHz APT signal is difficult, letalone a 1.7 GHz or 12 GHz signal. Therefore, that part of thefrequency spectrum which contains the signal(s) of interest
is first converted to a lower frequency band. After that, thespectrum is digitised and sent to the computer. So a little
hardware-processing is still needed, especially for amplifying
and down-converting the signal. The computer will then takecare of the remaining processing: filtering, demodulation,
decoding FM radio stereo or even demodulating AM to get the
picture from the 2400 Hz carrier of an APT signal.
HardwareRecently TV/FM receivers in the form of USB dongles havebeen coming on the market. They are meant for the receptionof digital TV (DVB-T) and radio via a PC. Because of the big
market for these devices they are extremely cheap; I boughtmine for just €16.
These devices contain two parts: the amplifier/downconverter part, and the TV-part. Some of these receivers
can be ‘misused’ as a front-end for Software Defined Radio;
the output of the down-converter, after digitisation, is sent
directly to the computer (via USB), bypassing the TV/radio
part. The device I have can handle input frequencies from48 MHz up to 1700 MHz ( although there seems to be a
unusable gap between 1100 MHz and 1250 MHz).
The USB-dongle (figure 1) contains:• An antenna input (top-right),• A tuner, converting a part of the spectrum to a lower
frequency band,• An 8-bit AD-converter, capable to handle up to threemega samples per second,• a TV/radio processing part, which is not needed, and is
bypassed for SDR,
• A USB-interface, to send the digitised signal to thecomputer.

14

Figure 1 - This is the entire hardware part of the APT receiver.

Note that, for normal applications of this dongle (TV, radio),
there is no real SDR involved: signal processing is done by
hardware inside the dongle.
Software
The dongle used for SDR does, of course, need software for:1 Control: Tuning, where it selects the frequency band to
be processed (maximum bandwidth 3 MHz)
2 Processing: The actual Software Defined Radio part.
For FM radio, the 3 MHz bandwidth is too small to catch thewhole 87-108 MHz band, so the dongle-receiver needs to be‘hardware-tuned’. But processing a single radio channel is no
problem. A single channel of classic TV (4.5 MHz, with soundcarriers 5.8 MHz) cannot be handled at all, because of the
bandwidth of 6 MHz.
On the other hand, the frequency band containing NOAA-APT(between 137 and 138 MHz) can be handled as a whole,meaning that, in principle, multiple NOAA signals could beprocessed simultaneously with one single dongle.
A nice piece of free software is available from theInternet: SDR# (pronounced as ‘SDR Sharp’) [1]. This contains
both the control and processing functions. Figure 2 shows
the software in use while recording an APT signal fromNOAA 18. At the top of the image you can see the received
frequency spectrum. The signal is not strong at all, butthat has to do with my antenna set-up. The lower part ofthe image displays the so-called ‘spectrum waterfall’, which
visualises the signal strength on each frequency in time, time
being shown along the vertical axis. Therefore, the picture‘moves’ from top to bottom, like a waterfall. The colour shows
the signal strength: blue is weak and red is strong (a coloured
version of this figure appears on page 4).
The control panel for both for the hardware (frequency centre)
and software (received frequency and all the other buttons)
functions is at the left of the screen.

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GEO Quarterly No 37

Figure 2 - The computer screen showing the SDR# software while receiving a NOAA APT signal.

The actual SDR settings are:• Bandwidth filter• Demodulation type: Narrow band FM, Wide band FM,
AM SB etc.
• AF gain (after demodulation)

see from figure 3, which was made using an indoor crossed
dipole antenna with no separate preamplifier used: just thedongle itself. My hardware receiver, which is certainly not thebest there is, gives better results.

Besides this, the signal, following demodulation, is sent to theaudio part of the PC and, with newer versions of SDR#, it caneven be recorded, resulting in a .wav file on the hard disk.
For APT, the IF bandwidth is set to 50 kHz, and wideband FM(WFM) is chosen. Narrowband FM might sound more logical,
but the NFM demodulator has too narrow a band for APT,
less than 25 kHz. Unfortunately, my receiving conditions are
currently too bad to do a fair comparison between the two
types, but I have heard from others that the narrow band FM
option is really unsuitable for APT.
Post Processing
Post processing can be done with programs like WXtoImg,
and there are two possibilities:
1 Connect the sound output of the PC to the sound inputof another (or the same) PC and record directly using
WXtoImg.
2 Use the recording feature in SDR#, resulting in a .wav
file. This .wav file needs first to be converted to a sample
rate compatible with wxtoimg: 11025 bytes/sec since therecorded sample rate is not adjustable in SDR#, as far as
I can see. This conversion can be done using Audacity,
a free audio editor/recorder [3]. Apart from sample rateadjustment, the sound also needs to be amplified (with
Audacity) to obtain a usable .wav file for WXtoImg.
(Note: There are two sample rates in this story: the SDR
sample rate when digitising the received signal, and theaudio sample rate, used to record the sound signal.)This simple receiver doesn’t make your expensive APT
receiver obsolete. There are some disadvantages: the noise
figure is not very good and it is more sensitive to pager
interference. Still, very acceptable results are possible. As
said, my receiving conditions are not very good as you canFigure 3 - A NOAA image recorded with an indoor antenna and SDR#

Figure 4 shows what is possible with a good APT antenna,
again without using a preamplifier. This NOAA 19 picture
was received by one of our Kunstmanen members, Peter
Kooistra, using:• Antenna: WSP 137 (a cross dipole with ground plane)• SDR-stick: Hama Nano
• Demodulator: WFM• Bandwidth: 50 kHz
Wxtoimg was used to record directly the sound from SDR#.
Other Points to Note
The HF Sample Rate may be too high for your PC to handle.
This can be tested by tuning into an FM radio station. If
the sound sometimes stops, then decrease the data rate to
1 Mb/s (the default is 2 Mb/s, the maximum is 3 Mb/s.)
HF Gain: This is done in the dongle, but under the control ofsoftware. It can be controlled by AGC or manually. AGC may
not work properly for weak signals, in which case, switch
it off and set the gain manually to a higher level (note thatmaximum gain also may give problems).

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Both settings are hidden behind theConfigure button, at the very top of the
SDR# window. Note that the buttons
in the software sometimes change fromversion to version; in figure 2, whichshows an older version, the button iscalled ‘front end’, and is located below
the frequency settings.
Another interesting feature isrecording. Instead of the audio alone,
the baseband (the digitised signal
before any SDR processing) can also
be recorded. That may be of particularinterest if experimentation with different
SDR settings is needed at the same
input signal, or to test self-made oradapted SDR-software (the source codeof SDR# is available from internet).
A received digitised signal is thenalways available. SDR# can read therecorded baseband file, and different
settings at the same signal can be done.
That includes tuning at a particularfrequency within the received range.
This way, simultaneous reception ofmultiple (APT) signals (and afterwards
decoding them one by one) is a reality.
Note that this recording option resultsin huge files, so don’t enable it if notneeded.
Other Applications
Connecting a length of wire to theantenna input gives an FM stereo
receiver. Unfortunately, short wave
radio isn’t possible using this dongle
alone as its lowest frequency is 48 MHz.
Connected to cable-TV, the received
frequency spectrum around a TV
station can be observed but, as said
earlier, the received frequency bandis unfortunately a maximum 3 MHz.
But with a bit of shifting of the central
frequency, the video carrier is visible,
as well as the sound carriers at 5.5 and5.74 MHz (I think these values are a bit
different in the UK). The sound carriers
are FM modulated, so they can beprocessed by SDR# and made audible(one at a time, so not in stereo).
An other application can be tracing
interference signals. A wireless alarm
I have, using 433.9 MHz, sometimes
had a very short range. Using a netbook
with a dongle and SDR#, I was able tosee a carrier containing an FM audio
signal at the same frequency. Walking
with my netbook+dongle in the street,
I was able to trace the transmission,
which appeared to come from aneighbour’s wireless headphone. Theychanged their frequency (shown nicelyin the spectrum on my netbook), andmy alarm started working properly
again.
Conclusion
This is a very versatile receiver, fornearly no money. Maybe it is not
a replacement for a hardware APT
receiver, but it’s still a nice gadget
to have and to ‘play’ with. Adding a

16

Figure 4 - NOAA 19, recorded by Peter Kooistra, using the SDR dongle.

preamplifier and/or pre-filtering may
be necessary to give more acceptable
results for specific applications, like
APT.

redistribute it or redistribute modified
copies (derived works.) The rest of theapplication is under the MIT license.’

The SDR# software (written in C#) is
still under construction, so checking
the website [1] now and then for new
features is advisable.

1 SDR# web-site - http://sdrsharp.com
Program for Windows:
http://sdrsharp.com/downloads/
sdr-stable.zip(the current version I use is v 1.0.0.1000)
2 USB driver for SDR#:
WinUSB, http://sourceforge.net/projects/
libwdi/files/zadig/
3 Audacity - http://audacity.sourceforge.net/‘The code of the DSP is released under
the MS-RSL license. This basicallygrants you the right to view the codefor your own education, but you cannot

www.geo-web.org.uk

References

March 2013

The Group for Earth Observation

GEO Quarterly No 37

Andreas Lubnow, DL6AAS (a.lubnow@ieee.org)
Background
Basically, this article is about environmental monitoring. It all began, when Geiger-Muellercounter kits with an RS232 interface became available for around €50. Since this interface
produces an impulse count value every minute, I started to think how I could include thesenumbers alongside the values I already gather from and about EUMETCast (BER, SNRetc). Since I have been following David Taylor’s approach using MRTG for gathering thatdata, I came up with a method to include these radiation numbers too.
In short, I use a COM-Server to be able to publish those values in a network, use theSens2Serv! shareware software to store them in a MySQL database, use a Perl script tocall them with MRTG, and publish the resulting graphics and webpages.
Technikakademie Braunschweig(Braunschweig Technical School) is a
public vocational school in the City ofBrunswick, Lower Saxony, Germany.
http://www.technikakademie-bs.deFounded some 85 years ago, and withcurrently over 600 students enrolled, itis the largest technical school in Lower
Saxony and one of the largest nationwide.
Training is offered in civil engineering,
electrical engineering, computer science,mechanical engineering, and mechatronics.
To motivate technical issues, as well as toillustrate and deepen instructional content,
our school maintains and operates anamateur radio station with the call sign
DL0TSB. Currently the station is active
on shortwave and on 2 m / 70 cm, here
mainly in APRS and PR, and may also be
contacted via EchoLink. Reception facilities
are available for the Meteosat EUMETCastand the now terminated ESA Envi-Ham data
streams, 137 MHz WXSAT, RTTY, HF-FAX,
and for numerous digital modes such as
HFDL (data transmissions from aircraft)and D-ATV. Additionally, a Perseus SDR
receiver ranging from 10 kHz to 30 MHz isavailable online.
Our Present Infrastructure
As part of the curriculum, students haveto carry out a 160 hour project, the goalof which is the development of theiroccupational competence. The EUMETCast
data stream facility, including the processingof the received images for the World Wide
Web, was set up as part of one suchproject. In the context of another project, aJava-based application had been developed
to store data gathered from a WS2300 typeweather station into a MySQL database forpresentation and further processing.
With the arrival of an AS622 Geiger
counter and an AS602 counter module,
developed by DL3HRT and sold by
AATiS [1] as a kit for around €50, we
have now had the opportunity to expand
the scope of environmental data witha new and interesting value. AATiS is
short for Arbeitskreis Amateurfunk und

Telekommunikation in der Schule e.V.
(Amateur Workgroup for Amateur Radioand Telecommunication in Schools). Everyminute, this counter module provides afigure correlated to radiation in the beta
and/or gamma range, depending on the
counter tube used. This figure is called theIPM (Impulses per Minute) value. So, thetask was to integrate these IPM values into
the existing infrastructure of data storage,
processing, and visualisation. The starting
point of this work was that the following
function blocks already existed:* MySQL database for storing the
WS2300 generated weather data,* MRTG installation for the visualisationof data e.g. weather data, EUMETCast
reception data, plus other relevant
network data such as throughput,* Automated upload procedures for thepresentation of data on the WWW.
Building the Counter
The layout and schematics of the Geiger
counter and the counter module arebased on an article published in 2011 in
the German magazine AATiS Praxisheft
22. The design is pretty straightforward,
comprising just five transistors and a few
other components for the actual Geiger
counter, and a small prefabricated printed
circuit board for the counter module withLCD display and RS232 serial interface.
Originally a single tube design, we havebuilt the counter on two breadboards in a
simple plastic housing (figure 1). One circuitboard accommodates the power generation
block (transistors T1 - T3) to operate thecounter tube at a few hundred volts (seebelow), and the other board houses that
portion of the circuitry (transistors T4 - T5)
to interface with the counter module and to
flash an LED whenever a radiation incident
occurs. The entire circuit is supplied from anexternal 5 V DC power source.
The design with those two breadboards
was chosen so that an existing counter
tube, model SI39G, could easily be placed
between the boards. Additionally, an
external counter tube can be attached witha BNC connector and a short coaxial cable.
This enables us to operate the significantly

www.geo-web.org.uk

Figure 1 -The Counter Module mounted
in its Plastic Case

more sensitive model LND72511 countertube [2] as an external tube (figure 2).
A switch is used to choose between these
two tubes (cold selection) and to properly
select the correct operating voltage for the
tubes, 400 V for the SI39G and 500 V for
the LND72511. The setup, with two different
counter tubes, has some additional benefits,
because comparative measurements
between the counter tubes are possible aswell as operation without a bulky external
tube.
Figure 1 shows the Geiger counter andcounter module. The counter module
display is at the front, the SI39G is to theleft, between the breadboards, and the BNC
connector and switch for tube operating
voltage selection are on the back. Figure 2
shows the model LND72511 counter tube,
base mounted with a BNC connector cable.

Figure 2 - The LND72511 Counter Tube

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What Data is to be Processed?
As already mentioned, the counter module unprompted, delivers an
IPM value at its RS232 interface every minute. By nature this value
is an integer, i.e. a simple number without sign and decimal point,
which comes at a data rate of 4800 bit/s in the popular 8N1 format.
Figure 3 shows an 18 minute trace recorded with serial sniffer
software. We have used Procomm Plus, but of course any otherserial sniffer software will give a similar result.

Figure 4 - Recording the IPM values (counter tube LND72511) sent via Telnet

client to a server, you simply type telnet x.x.x.x from the commandline interface, where x.x.x.x is the IP address of the COM server.
How to store Network Published Data into a Database

Figure 3 -Recording of the data available at the RS232 interface of thecounter module with the LND72511 counter tube attachedPublishing Serial Data on the Network
To store the IPM values in a database for further processing, atwo-step procedure is used. The first step is to feed the unmodified
serial data to a server—available on the local network—from where
it is then written automatically into a database in a second step.
For step one, there is a choice between pure software solutions
such as Piracom [3] and a serial COM server as a standalone
hardware setup. In both cases, any other networked device canpick up the data available at that serial RS232 interface. We havedecided to go for the hardware solution, since this variant turns out
to be very compact and it does not require a dedicated serial COM
port—which is no longer readily available on some modern-day
computers. We have acquired a Mini/Industry 58211 COM server
from Wiesemann and Theis (W&T) (figure 5, page 20). This device
may be operated not only as a Telnet server or as a telnet client,but also as an FTP (file transfer protocol) server or client.
Telnet is a protocol for terminal emulation, where the datatransmission is character-based. Telnet permits an active exchangeof characters between an attached serial device and the COM
server, and vice versa. This return path may be used should theserial device have an option for signalling. When operating as a
Telnet server, the incoming serial data will be forwarded to thestandard Telnet port 23 of the COM server. This mode is usefulfor ‘listening’ to the data production of a serial device such as
our Geiger counter, so we use this setting in our project. When
operating as a Telnet client, a serial terminal attached to the COM
server may connect with a Telnet server available on the network.
This mode is not used in our project.
In contrast, the exchange of data via FTP is not character-based
but file-based. With FTP it is possible to write or read entire files toor from the serial interface of the COM server. But since the IPM
values are one continuous sequence of characters, reading them asa file will never be finished, ruling out both FTP modes.

Now, the IPM values are available throughout the network, andwe are one step closer to storing them in a database. An Internet
search directed us to Sens2Serv! [4]. This shareware takes datafrom networked sensors and (measurement) equipment and writes
formatted data fields into any database system (Oracle, Access,
SAP, MySQL, DB2, FoxPro, ...) or to a CSV file. After installation,
Sens2Serv! is ready to access Oracle and Access databases, butother databases like MySQL may be accessed via a connection
string as well.
When an application connects to a database or a data file you
let ADO or ADO.NET utilise a provider to do the job for you. A
connection string contains the information that the provider needs
to know to be able to establish a connection to the database or thedata file. Because there are different providers, and each provider
has multiple ways to make a connection, there are many different
ways to compose a connection string [5].
A connection string consists of a series of ‘Keyword-Value Pairs’
separated by semicolons. An equals sign (=) connects eachkeyword and its value. The information in the connection string is
passed on to the provider. Our connection string looks as follows{MySQL ODBC 5.1 Driver};Server=x.x.x.x;Database=as622;User=user;Pa
ssword=password;Option=3;
As seen in this connection string, ‘{MySQL ODBC 5.1 Driver}’, theappropriate MySQL ODBC driver is required. At the time of writing
this was driver version 5.1. http://www.connectionstrings.com very
comfortably guides you to the correct connection string, and in
addition gives a link to the correct driver for a number of different
database systems and applications. After driver installation, it
should appear (figure 7) in the driver tab underControl Panel -> Administrative Tools -> Data Sources (ODBC)
Obviously, a MySQL database system must also be available.
XAMPP [6] is a good starting point should you have to install one,since it not only installs MySQL but also a plethora of useful tools
and packages.

W&T offers the easy-to-use configuration software WuTility for theirdevices. We have used this software to set all parameters of theinterfaces (4k8, 8N1, IP settings of the COM server) and the modeof operation (Telnet server mode, figure 6).

Going back to the connection string once more, the entry‘Database = as622’, the target database, ‘as622’ in our case, mustalso be accessible. In the case of MySQL, access may be checkedwith HeidiSQL [7]. Other database systems come with similar
client software and/or have a web browser interface to access the
database system.

With the Geiger counter now linked to the COM server and thenative Windows telnet client connected to this server, the screen
shows the familiar IPM values, but this time transported via the
Telnet network protocol (Figure 4). To connect a Windows telnet

To create a new database on a database system, the correct
SQL command is ‘CREATE DATABASE as622;’, where ‘as622’ is the
database name, which of course can be chosen differently. SQL
stands for Structured Query Language and is a standardised18

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The Group for Earth Observationcommand and query language for database systems. It is important
to note that a semicolon terminates each SQL statement before it
is sent to the database system. For better readability, the use ofcapital letters is common practise with SQL, but not essential.
Finally, we have to create a table for the storage of—and access
to—the IPM values. Since Sens2Serv! will have to fill thistable, Sens2Serv! and this table should follow identical naming
conventions for fields and types. In our case, the SQL command tocreate the table ‘as622’ is as follows:
CREATE TABLE `as622` (`as622` INT(10) UNSIGNED NULL DEFAULT NULL,`datum` CHAR(50) NULL DEFAULT ‘kein datum’,`zeit` CHAR(50) NULL DEFAULT ‘keine zeit’,`zeitstempel` CHAR(50) NULL DEFAULT ‘kein zeitstempel’ );This table contains four fields of sufficient field size (10 or
50 characters, respectively). The first field (field type integer) is
called ‘as622’ and will later collect the IPM values. The following
three fields are of field type character and, unlike integer declared
fields, may also contain non-numerical strings.
The reason for this is that Sens2Serv! conveniently provides
the option to add time and date information alongside the IPM
value. Colons are included in this information, thus requiring thecharacter field type CHAR. NULL means that a value for this field
may be omitted. In this case the specified default value is enteredautomatically. For expressions consisting of more than one word
like ‘kein zeitstempel’ (no timestamp), the entire expression has
to be placed in quotation marks. Again, it is helpful to check thecorrect execution of this CREATE command with HeidiSQL.
After these preparatory steps, we can proceed with theconfiguration of Sens2Serv! Figure 8 shows a number of statements
to be entered in the ‘Datei’ (file) configuration tab. Since we intend
to use a MySQL database system, the database type to choose is‘user-defined’. The connection string and the table structure havealready been discussed above. The four field names and field types
have to match those in the table definition, and are correlated with
Ausschnitt (Section) 1 to 4 (figure 9). Defining the length of the field‘as622’ carrying the radiation data as 10 significant digits with zerodecimal places (Dec = 0) seems to be sufficient for IPM values.
Those of the three other fields have to agree with the structure of
the time and date information generated by Sens2Serv!

GEO Quarterly No 37

of reception (figure 13). The ‘as622’ field holds the IPM values:
date and time are available in the DD.MM.CCYY (field datum)and HH:MM:SS (field zeit) format, respectively. The ‘Zeitstempel’(Timestamp) field conveniently combines date and time in justone field without any dots and colons, and with four additional
millisecond digits, making it very easy, for example, to find the latest
IPM value.
Based on the LND72511 data sheet, IPM values can also be
converted into a dose without difficulties. If we restrict ourselves tothe linear section in the double logarithmic representation, that is
IPM values below 250,000, the following approximate formula may
be used:
Dose in mGy/Hr = (IPM value / 347562) ^ 1,0748388
This formula uses the fact that the relationship between dose andIPM value can be described by a power function. Until now all IPM
values measured were well below 250,000, so this limitation is moreof a theoretical nature. ‘Gray’ (Gy) is a unit derived from the SI units
joule and kilogram, and describes the absorbed energy per masscaused by ionizing radiation. For X-ray, gamma, and beta radiation,
one gray is identical to one sievert [8].
Processing Data
Since the IPM values are stored in a database, they can beprocessed in many ways. Two approaches of different complexity
will be briefly presented here.
1 Generation of an Include File for shtm or shtml files, so called
Server Side Includes (SSI)
2 Processing of data using MRTG (Multi Router Traffic Grapher),a programme for graphical analysis and display of numerical
data, which has already featured extensively in earlier editions
of GEO Quarterly [12 - 14].
Creating and Embedding an Include FileTo easily integrate dynamic values into a web page, include files
are a fine alternative to the more complex PHP. A prerequisite,though, is that the Web server needs to accept server-side includes(all web servers can be configured to do so), and that the website’s
file needs to be uploaded to the web server as shtm or shtml.
These do not differ in any way from conventional htm or html files:
the leading ‘s’ in the file extension indicates the include mechanism.
To include dynamic data, we run the SQL command
select as622 into outfile ‘C:/transfer/ipm.txt’ fromas622 order by zeitstempel desc limit 1;

As just mentioned, sections 1 to 4 are defined in the protocol
configuration tab. Every minute, Section 1 (field ‘as622’) picks up
the first 10 characters received from the RS232 port and interpretsthese as a number. Sections 2 to 4 are filled with Sens2Serv!’s
own date, time, and timestamp values, respectively. This is a nicefeature to automatically correlate each received IPM value with aproper timestamp.

invoked by a script every 15 minutes, asking for the latest IPM
value written to the file ipm.txt which, in our case, resides in thefolder C:/transfer/. Prior to that, however, we have to run

The next step is to integrate the W&T COM server in the device
configuration tab (figure 10). Plausibility checks of the received
data, for example (IPM value >= 0), are defined in the check tab(figure 11). Entries in the feedback tab are not required, since nocommands have to be sent to the counter.

to delete the existing ipm.txt, otherwise this export will not work.
This SQL command sorts the content of the field ‘as622’ indescending order (desc) according to data in the ‘Zeitstempel’(Timestamp) field, then limits the result to just the latest entry(limit 1), re-directing the query result into a file (into outfile). This fileis subsequently transferred via FTP to the web server. There, thisfile will be called by

After clicking the green ‘Anwenden’ (Apply) button, a new IPM
value should appear in the monitor tab every minute (figure 12).
The two characters trailing that numerical value show the ASCII
characters CRLF, which is the Windows ENTER key, and is sentby the counter with each value. A red status ‘EIN’ (ON) signals that
the COM server is connected properly, a blue message ‘as622 ok’means that the database access is working as well.
Since database access is now up and running, a complete set ofdata is now stored every minute. Again, this should be checkedwith the HeidiSQL client software. After a successful login to
the database system, and selecting the database and the table,the ‘Data’ tab in the main window displays the data in the orderdel C:/transfer/ipm.txt<!--#include file=”ipm.txt” -->placed at the desired position in the page’s source to show thelatest IPM value
http://212.28.102.138/wx_history.shtm

Processing with Multi Router Traffic Grapher (MRTG)
The graphical representation of numerical values with MRTG [15]offers more functionality but is somewhat more complex toconfigure. MRTG was originally developed to measure network
traffic data and to automatically generate and update web pages
Continued on page 21

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Figure 8 - Configuring Database Access with Sens2Serv!

Figure 5 -The Mini/Industry 58211 COM server. The RS232 interface isto the left and the Ethernet-based network interface to the right.

Figure 9 - Defining Field Contents

Figure 6 - Configuration of the COM server with WuTility

Figure 10 - Integrating the COM Server

Figure 7 -20

The MySQL ODBC 5.1 driver has been installed correctly
and can be addressed with the connection string

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Figure 11 - Plausibility Checks of the Received Data

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GEO Quarterly No 37

Figure 12 - Reading Live Data and Sens2Serv! Status Messages

Figure 15 - wperl.exe is listed in the Task Manager, hence MRTG is running.

Figure 13 - The Database fills up with IPM Values
Figure 16 - IPM values measured at our location

displaying that traffic data. When configured properly, MRTG canvisualise almost any positive integer value.
To work with MRTG, Perl has to be installed first [9] because MRTG
is Perl-based. But beware: after the initial installation, Perl has to bemade ‘database-capable’, since database content is be visualised.
To do so, run the Perl Package Manager and install DBI, thedatabase-independent Perl interface (figure 14).
The Perl script above (Listing 1) takes care of the actual database
query and hand-over of the result to MRTG.
It is stored as ‘as622_ipm.pl’ in the MRTG \bin folder. Clearly visible
are the connects and disconnects of the database connection,
the SQL select statement, and the ‘data print-out’ for MRTG (thefour print statements), as MRTG expects data in this format. The
reader is advised to consult MRTG’s documentation for in-depth
explanation of these statements
http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html

MRTG starts by calling
C:\Perl\bin\wperl.exe mrtg --logging=eventlog mrtg.cfg

Figure 14 - The Perl Package Manager lists all installed
packages of the Perl Installationfrom the mrtg\bin folder. Since the user is not alerted to errors
in the scripts and/or the mrtg.cfg file, it is wise to check the Task
Manager and look for the wperl.exe entry (figure 15) to verify that
Perl and MRTG are running. If you want to stop MRTG, you have toterminate the wperl.exe process through the Task Manager. MRTG
by default generates four different graphs representing the courseof the IPM values over a day (figure 16), a week, a month, and ayear.
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use DBI;$dbh = DBI->connect(‘DBI:mysql:as622;host=x.x.x.x’, ‘user’, ‘password’,{ RaiseError => 1 });$sth = $dbh->prepare(‘select as622 from as622 order by zeitstempel desc limit 1’);$sth->execute();$result = $sth->fetchrow_hashref();
print “0\n”;
print “$result->{ipm}\n”;
print “0\n”;
print “0\n”;$dbh->disconnect();
To make use of this script a few lines have to be added to the mrtg.cfg. It must be noted though that all statements in parentheses are for illustration
only and not part of mrtg.cfg
Timezone[_]: local time
(Time base for MRTG)
Options[_]: growright(Graph grows from left to right)
Interval: 5(MRTG collects data every 5 minutes)
EnableIPv6: no(No network queries using IPv6)
RunAsDaemon: yes(MRTG daemon mode, useful for continuous operation)
WorkDir: C:\mrtg(MRTG working directory)
Listing 1
The Perl Script which takes care of#--------------------------------------------------------------the actual database query and hand#
AS622 IPM
over of results to MRTG#--------------------------------------------------------------Target[AS622_ipm]: `perl as622_ipm.pl`(MRTG data source)
MaxBytes[AS622_ipm]: 150(Maximum value of variable 1 (IPM values))
MaxBytes2[AS622_ipm]: 150(Maximum value of variable 2 (not used here))
Title[AS622_ipm]: AS622 Impulses per minute(html title of the generated web page)
Options[AS622_ipm]: integer, gauge, nopercent, growright(integer: values are integer, gauge: data values are absolute not incremental, nopercent: no percentages, growright: graph grows from left to right)
YLegend[AS622_ipm]: IPM(Legend of the y-axis)
ShortLegend[AS622_ipm]: .
(Unit string for Max, Average and Current)
LegendI[AS622_ipm]:(String of Bytes in)LegendO[AS622_ipm]: IPM:&nbsp;(String of Bytes out)
Legend1[AS622_ipm]:(String of variable 1)
Legend2[AS622_ipm]: IPM(String of variable 2)
PageTop[AS622_ipm]: <H1>AS622 Impulses per minute</H1>(Additional information at the beginning of the web page)#--------------------------------------------------------------At Technikakademie Braunschweig, we use MRTG to some extent
http://wetterprojekt.ta-bs.eu/mrtg/

In addition to the EUMETCast data stream values for data traffic,
packet loss, reception quality and strength, bit error rate (BER) andsignal-to-noise ratio (SNR), plus values derived from our WS2300
weather station for temperature, humidity, air pressure, rainfall, dew point,
wind chill and wind speed, we also run MRTG on our uninterruptible
power supply and our GPS-based NTP timeserver.
To analyse network related data with MRTG, an SNMP agent has
to be enabled on the device to be monitored. Simple Network
Management Protocol (SNMP) is an ‘Internet-standard protocol for
managing devices on IP networks.’ Devices that typically support
SNMP include routers, switches, servers, workstations, printers,
modem racks, and more [10].
On a Windows computer, the SNMP agent can be installed throughControl Panel -> Software -> Add Windows Components -> Management andMonitoring Tools -> SNMP. You configure and run the SNMP agent as aservice in Administrative Tools -> Services.
To monitor more specific items such as the UPS load you have to
make use of so-called Object Identifier (OID) [11] which has a very
comprehensive list of these OIDs.
SummaryThis paper shows how data from a home-built Geiger counter canbe processed using standard software and hardware and made22

ready for display on the Internet. The following processing chain
was set up:
Geiger counter -> COM server -> Sens2Serv! -> MySQL database -> MRTG -> www
All scripts and configuration files are available from the author, on
request, ata.lubnow@ieee.org

References
1 AATiS - www.aatis.de
2 LND72511 counter tube - http://www.lndinc.com/products/156/
3 Piracom - http://pira.cz/eng/piracom.htm
4 Sens2Serv!
http://www.serielleschnittstelle.de/index.php/
standard-software/sens2serv.html
5 How to compose a connection string
http://www.connectionstrings.com/Articles/
Show/what-is-a-connection-string
6 XAMPP - http://www.xampp.de
7 HeidiSQL - http://www.heidisql.com
8 Gray - http://de.wikipedia.org/wiki/Gray
9 Perl - http://www.activestate.com/activeperl
10 SNMP Devices - http://en.wikipedia.org/wiki/SNMP
11 Object Identifier - http://www.oidview.com/mibs/detail.html
12 Monitoring EUMETCast (D Taylor) - GEOQ 8, pp 5-6
13 Extending EUMETCast Monitoring (D Taylor) - GEOQ 21, pp 33-35
14 David Taylor’s MRTG Guide
http://www.satsignal.eu/mrtg/performance_howto.php
15 Graphical Representation with MRTG
http://oss.oetiker.ch/mrtg/

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Adapted from a Science@NASA Report - January 15, 2013
NASA scientists have determined that 2012
was the ninth warmest of any year since
1880, continuing a long-term trend of rising
global temperatures. With the exceptionof 1998, the nine warmest years in the
132 year record have all occurred since
2000, with 2010 and 2005 ranking as thehottest.
NASA’s Goddard Institute for Space Studies(GISS) in New York, which monitors global
surface temperatures on an ongoing basis,
released an updated analysis that comparestemperatures around the globe in 2012 withthe average global temperature from themid 20th century. The comparison shows
how Earth continues to experience warmer
temperatures than were prevalent several
decades ago.
A video showing a colour-coded map
displays a progression of changing global
surface temperatures anomalies from 1880
through 2012. The final frame represents
global temperature anomalies averaged
from 2008 through 2012. It can be viewed
at the following URL

Figure 1 - Mean Global temoperatures in 1884

http://science.nasa.gov/media/medialibrary/
2013/01/15/splash2.jpg/image_full

The final frame of the video represents
global temperature anomalies averaged
from 2008 through 2012. Figure 1 shows
the video frame for 1884 and figure 2 thatfor 2012.
The average temperature in 2012 wasabout 14.6°Celsius, 0.6°C warmer thanthe mid 20th century baseline. The new
analysis indicated that the average global
temperature has risen about 0.8°C since
1880.
Scientists emphasise that weather patterns
will always cause fluctuations in averagetemperature from year to year, but thecontinued increase in greenhouse gaslevels in Earth’s atmosphere assures along-term rise in global temperatures.
Each successive year will not necessarily
be warmer than its predecessor, but on
the current course of greenhouse gas
increases, scientists do expect eachsuccessive decade to be warmer than theprevious one.
“One more year of numbers isn’t in itself
significant,” maintained GISS climatologist
Gavin Schmidt. “What matters is that thisdecade is warmer than the last one, which

24

Figure 2 - Mean Global temoperatures in 2012

in turn, was also warmer than the decade preceding it. The planet is warming because weare pumping increasing amounts of carbon dioxide into the atmosphere.”
Carbon dioxide is a greenhouse gas that traps heat and largely controls Earth’s climate.
It occurs naturally and is also emitted when fossil fuels are burned for energy. Driven byincreasing man-made emissions, the level of carbon dioxide in Earth’s atmosphere has
been rising consistently for decades.
The carbon dioxide level in Earth’s atmosphere was about 285 parts per million in 1880,
the first year in the GISS temperature record. By 1960, the atmospheric carbon dioxide
concentration, measured at NOAA’s Mauna Loa Observatory, had risen to some 315 parts
per million. Today, that measurement exceeds 390 parts per million.
While the globe experienced relatively warm temperatures in 2012, the continental US
endured its warmest year on record by far, according to NOAA, the official keeper of US
weather records.

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two plates run into each other or slide past each other. Figure 3
shows the planet’s main oceanic and continental plates and theirboundaries. The map (figure 1) shows the Apennine thrust, closeto Emilia-Romagna, where approximately one millimetre per yearof active movement, is taking place. The Apennine thrust has
produced several damaging historical earthquakes in this area,such as the one at Ferrara in 1570.
Different Characteristics of Earthquakes and their Effects
Geologists measure earthquake motions and study theircharacteristics measuring their period, amplitude, frequency anddirection of motion of their seismic waves. The point where an
earthquake actually originates is called its hypocentre (or focus),
and can lie deep within the Earth. The point on the surface of the
Earth, directly above the focus, is known as the epicentre.
An earthquake produces two types of waves, Body Waves thattravel through the interior of the Earth, and Surface Waves, thatmove across the planet’s surface.

Esko Petäjä
I have business friends living in the region of Emilia-Romagna
in northern Italy, and heard from them that a large earthquake
occurred near where they live last May. The map below (figure 1)
shows the area where the earthquake took place, and figure 4
illustrates the effect of the quake on buildings in Cavezzo, Modena
province.

There are two forms of Body Wave: P-waves (primary waves),
longitudinal compression waves that travel in the direction of
propagation and S-waves (secondary waves), shear waves
transverse to the direction of propagation. P-waves travel throughany type of material at speeds ranging from 5000 m/s in granite and1450 m/s in water. S-waves travel more slowly, and only throughsolids (at roughly 60% of the speed of P-waves), yet are more
powerful and often much more destructive.
When the energy of an earthquake reaches the surface of the
Earth, it creates two types of Surface Waves, each named afterits discoverer. Rayleigh Waves have an amplitude that decreases
exponentially with the depth of the hypocentre and can travel
around the Earth’s crust several times before dissipating. Rayleighwaves cause the ground to shake in an elliptical motion, and travelwith a rippling motion similar to the that of waves on water. Love
Waves move the ground from side to side in a horizontal planeat right angles to the direction of propagation. The horizontal
shaking resulting from Love Waves is particularly damaging to thefoundations of structures (figure 6).
How Earthquakes are Monitored
When an earthquake occurs, elastic energy is released, sending out
vibrations that travel throughout the Earth. Earthquake vibrations
are detected on a seismometer, and are displayed as a trace ona seismograph. The seismometer must be able to move with thevibrations. Older seismographs, like the one drawn below, also
acted as a seismometer. Modern seismometers are piezoelectric,
piezo resistive or capacitive micro electro-mechanical systems(MEMS) devices.

Figure 1 -Map of Italy highlighting Emilia-Romagna province, the region
affected by the earthquake, and the Apennine thrust fault.

This raised my interest to study more how to monitor earthquakes
and how satellites are used today for earthquake prediction. I also
learned about an interesting earthquake monitoring system where
private users can share their information over a network and thenview the global earthquake situation on the QCN-Network.
I’m going to start with basic background information about
earthquakes before describing how this system works and how
to utilise it and the QCN-Network [1]. Finally, I will describe how
satellites are used to predict earthquakes today.
Where do Earthquakes Occur?
Earth’s crust is made from several pieces called plates, which are
moved around by convection within the mantle and are always
colliding or pulling away from each other. Earthquakes occur
throughout the world all the time, most of them along the edges ofoceanic and continental plates. Earthquakes usually occur where

26

Figure 2 - Principle of a simple seismographCredit: Copied from an original diagram by USGS

The significance of an earthquake is measured on the Richteror Mercalli scale ratings. The Richter scale was invented andnamed during 1935 by American seismologist Charles Richter,and is a measure of the total energy emitted by an earthquake.
The amplitude of waves recorded by seismographs are adjusted
mathematically for variations in their distances from the epicentre
to produce a magnitude index for the earthquake. This value is
not a measure of how much the ground shakes at any particular

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place but relates to the entire energy output of an earthquake. The
Richter magnitudes increase logarithmically, which means that theenergy of the quake increases tenfold with for each magnitude
number. The Mercalli intensity scale is based on observations
from earthquake damage and is not derived instrumentally. It was
Invented by the Italian seismologist Giuseppe Mercalli. Table 1
compares earthquakes in both Richter and Mercalli scales while
figure 3 shows a typical seismogram (the trace produced by aseismograph).
Richter
Mercali
Description
Magnitude Intensity
I
Usually not felt but detected by instruments.
2
II
Felt by very few people
III

Felt by many, often mistaken for a passing
vehicle.

IV

Felt by many indoors; dishes and doors
disturbed.

V

Felt by nearly everyone. People awakened.
Cracked walls, trees disturbed.

VI

Felt by all. Many run outdoors. Furniture
moves. Slight damage occurs.

VII

Everyone runs outdoors. Poorly built
buildings suffer severe damage. Slightdamage everywhere else

VIII

Everyone runs outdoors. Moderate to
major damage. Minor damage to speciallydesigned buildings. Chimneys and walls
collapse.

IX

All buildings suffer major damage. Groundcracks, pipes break, foundations shift.

X

Major damage. Structures destroyed,
ground badly cracked. Landslides occur.

XI

Almost all structures fall. Bridges wrecked.
Very wide cracks in ground.

XII

Total destruction. Ground surface waves
seen. Objects thrown into the air. Allconstruction destroyed

3

4

5

6

7

8

Table 1: Earthquake significance on both Richter and Mercalli scales.

GEO Quarterly No 37

1 - The Sensor
QCN sensors are Micro-Electro-Mechanical Systems (MEMS)
accelerometers, which are simply microchips with a very small set
of force-balance cantilever beams inside them. The balance mass
weight is compensated by a low-level electrical voltage. QCN uses a
series of sensor types, some embedded in devices such as laptops
and some connected by USB to computers. The QCN sensors
measure accelerations between -2g and +2g (where g is Earth’s
gravitational constant: 9·81 ms-2) along three axes, and the software
samples the sensor 50 times per second. The sensor used in mystation is shown in figure 8.
2 - The Processing
Requirements for the processing PC are minimal: it can be equippedwith Windows, Linux or Apple operating system. A powerful PC is
not needed. I use an Intel Atom unit using Windows XP, running
Plane Plotter and the weather station software at the same time
without any problem.
3 - The Software
The Software used in the QCN is BOINC (Berkeley OpenInfrastructure for Network Computing), an open source package
for volunteers to do grid computing. It was originally developed tosupport the SETI@home project, a scientific experiment that uses
Internet-connected computers in the Search for Extraterrestrial
Intelligence (SETI) by analysing radio telescope data. BOINC has
since become useful as a platform for other distributed applications
in areas as diverse as mathematics, medicine, molecular biology,
climatology, and astrophysics. The intent of BOINC is to make itpossible for researchers to harness the enormous processing powerof personal computers around the world. When a significant tremor
is detected at a station, the software sends a ‘trigger message’ tothe server in a small XML packet with enough information to figureout information about the quake (latitude/longitude, time, sensortype). Figure 9 shows the main QCN screen running in the BOINC
software. Tabs at the top of the screen display different project
statistics; the buttons on the left provide access to user accountsettings.
BOINC software operates a system which provides ‘Credits’ toeach user for work done for the project on their workstation. Theseamount to 50 ‘BOINC Cobblestones’ per 24-hours of sensor
monitoring [2].
4 - SAC Files
The software algorithm checks if motion was significant bycomparing each point with the standard deviation of the signal in
the long-term window prior to the trigger event. If the criteria match,
the SAC (Seismic Analysis Code) files are saved. This file includes
a one-minute recording buffer prior to the trigger and a two-minutebuffer after it.

Figure 3 -A typical earthquake seismograph showing
the arrival of P-waves before S-waves,
Credit: USGSThe QCN-Network
The Quake-Catcher Network (QCN) [1] provides software andsensors so that individuals can join together to improve earthquake
monitoring, earthquake awareness and the science of earthquakes.
At this moment there are around 1500 active sensors in the
network. If you are interested to obtain a sensor, the standard
package can be ordered fromhttp://qcn.stanford.edu/join-qcn/request-a-sensor

for the price of $49 US + shipment cost. The QCN network
software needed (BOINC) can be downloaded free of charge.
The QCN website has excellent detailed instructions on installingand configuring both sensor and software. I will describe how thissystem works and what its usage possibilities are. Figure 7 shows,schematically, the architecture of my QCN Station.

5 - The SAC File Viewer
SAC files contain binary data which can be visualised using special
Seismogram Viewer programs. The yellow trace shows the motion
vector in the north-east direction, red the east-west motion vector
and blue the up-down motion vector. The time line is shown at hebottom. The different waves can be seen clearly in the red graph(P-waves arrive first, followed by S-waves and finally ground waves).
I use the SeisGram2K seismogram viewer, freely available fromhttp://alomax.free.fr/seisgram/SeisGram2K.html

to visualise data. Figure 10 shows a SeisGram2K SAC visualisationfrom the Italian earthquake of May 20, 2012.
7 - The QCN Server
The QCN Servers (3 different units), based on Linux and the MySQL
database, are located in Stanford University, California, and consistof the following services:• Database• BOINC scheduler• Web pages• Data upload and analysis server• Event detection.

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Figure 4 - Buildings Reduced to Rubble

March 2013

Figure 5 - Map showing the Earth’s major Tectonic Plates

Photo: Mario Fornasari/Wikimedia

Image: USGS

Figure 6 - Love Waves (top) and Rayleigh Waves (bottom)

28

Image: USGS

Figure 7 - Schematic showing the Author’s QCN Station

Figure 8 - The Sensor used in the Author’s Station

Figure 9 - QCN Software running under BOINC

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GEO Quarterly No 37

Figure 10 - A SeisGram2K SAC trace of the May 2012 Italian Earthquake

Figure 11 - QCN Network Data for December 2012

Figure 12 - Principle of InSAR Radar
Image: USGS

Figure 14 - NOAA-AVHRR LST maps of Iran before and after the Bam
earthquake on December 26, 2003 (Choudhury, 2005)

Figure 15 - Rocks are working
like batteries effect.
Image: NASA/Ames Associate

Figure 13 - Movement measured by Envisat during Japan Earthquake

Figure 16 - Measurement methods for detecting
Ionospheric Disturbance
Image: SSTL

www.geo-web.org.uk

Image © ESA

Figure 17 - TEC measurement over the
Tohoku Earthquake in 2011
Image © NIICT, Japan

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The system has computed 60 million triggers over three years. If
the server determines that your PC has been involved in a seismic
event, it will send a request to upload the SAC (full waveform) files
for this event.
The Database Server manages all station information and trigger
information. The BOINC Scheduler handles BOINC client requests for
new work units, triggers, etc. The QCN Web Page Server carries work
to display all BOINC web pages including triggers etc.
The Data Upload Server receives a small (~300 byte) packet of XML
whenever a trigger occurs in a station. This file includes the event
time, host time offset, x/y/z sensor reading, significance thresholdetc. If the server determines that this computer was involved in aseismic event, it will send a request to the station to upload the
SAC (full waveform) files for this event (the BOINC ‘intermediate
upload’ feature). The Event Detection Server Processes scan the new
trigger (stored in a MySQL memory table) every 0.2 seconds, a
simple process which compares USGS-detected/reported eventswith our sensor network. The QCN Web Page Server shows recent
earthquake data, based on date from all its network stations at
http://qcn.stanford.edu/sensor/maptrig.php

Figure 11 shows QCN network data over Europe from
December 2012, as displayed on my PC workstation. Locations ofuser stations are indicated, and earthquakes shown as red markers.
You can display data for specific periods by adding a suffix to the
URL, for example,
http://qcn.stanford.edu/sensor/maptrig.php?timeint=D‘D’ = the last day, ‘W’ = the last week and ‘M’ = the last month.
Earthquakes can only be seen on this map and there is no interface
available to show the data on your own background or using GIS
software.
Earthquake Monitoring and Prediction by Satellites
There are multiple ways in which satellites can be used to predict
earthquakes:• InSAR (Envisat and ERS-2)• Temperature abnormalities detected by satellite• Ionospheric disturbances
InSAR (Interferometric Synthetic Aperture Radar)
There are a number of Earth orbiting satellites that carry InSAR
equipment, which works by sending down radar pulses andmeasuring the microwave energy that bounces back. Additionallythey can also record the phase of the returning waves. Two of
the best known satellites were ESA’s Envisat and the veteranERS-2 (which served for 16 productive years), but both have now
ceased operating. Both satellites carried onboard InSAR, and bycomparing the phase shift between radar images before and after
an earthquake, changes in ground position could be measured
with an accuracy of millimetres. Figure 12 illustrates the principle of
InSAR radar.

March 2013

between 5° and 10°C in surface temperature shortly before theevent (figure 14, where the star symbol indicates the epicentre).
Ionosphere Disturbances
The ionosphere is distinguished from other layers of Earth’s
atmosphere because it is electrically charged through exposure
to solar radiation. There are many cases when satellites havepicked up disturbances in this region of the atmosphere, 100 to
600 km above areas that have later been hit by earthquakes. Oneof the most important of these disturbances is a fluctuation in thedensity of electrons and other electrically-charged particles in theionosphere, which can be detected in many ways, including GPS
signals, VLF/ULF emission and VLF radio signal propagation.
The background and reasoning for this effect are that when rocks
are compressed—as when tectonic plates shift—they act likebatteries and generate electric currents powerful enough to bemeasured from orbit in multiple ways (figure 15). These include
the use of GPS satellite signals (1), magnetometers (2), satellites
capable of receiving VLF/ULF signals (3), IR emission (4) andmonitoring VLF Radio signal propagation (figure 16).
Of particular interest is the use of GPS satellite signals, where
the Total Electron Content (TEC) of the atmosphere is measured
by a ground station using the delay and phase shift between the
two GPS satellite frequencies (L1 C/A and L2 P/Y). Observations
show that concentric waves begin to appear in the ionospherea few minutes after earthquake onset, above the epicentre.
Figure 17 shows a TEC plot taken during the Tohoku Earthquake inMarch 2011.
Earthquake Early Warning Satellite System Activities
There was an article in GEO Quarterly 35 describing a GEO visit
to Surrey Satellite Technology Limited (SSTL) in the UK. During
my study, I found out that they are playing a very active role indeveloping a satellite-based early warning system. Their concept is
to make use of Disaster Monitoring Constellation satellites [3], small
satellites which cost only a fraction of the cost of normal satellites,
many of which are already active.
Usage of GPS Position to Measure Plate Movement
Geodesy is the science of measuring the Earth’s shape andpositions on it. It is possible to measure plate motions directly using
GPS. Plates typically move just few centimetres/year, but changes
could be used to predict earthquakes (figure 18)

Using data acquired on February 19 and March 21, a ground shiftof about 2.5 m eastwards and a downward motion of Honshu
Island’s east coast were been detected. Figure 13 show movement
measured by Envisat.
Temperature Abnormalities
During 1980s and 90s, Russian and Chinese scientists noticed
some strange thermal anomalies associated with earthquakesin Asia. Shortly before the Zhangbei earthquake near the Great
Wall of China in 1998, where ground temperatures in the region
had been around -20°C, thermal sensors detected temperature
increases as large as 6° to 9°C. This means that satellite IR
sensors could be useful for predicting earthquakes. Anotherexample was in western India just before the powerful Gujarat
quake on January 26, 2001 where thermal anomaly was aslarge as +4 C°. And in the case of the Bam quake in Iran on
December 16, 2003, post-earthquake analysis using NOAA AVHRR
land surface temperature data indicated a short-term increase of30

Figure 18 - Global plate motion measured by GPS on April 17, 2008
Image: NASA

References
1 Quake-Catcher Network
http://qcn.stanford.edu
2 Cobblestone (named after Jeff Cobb of SETI@home), is 1/200 day of
CPU time on a reference computer that does 1,000 MFLOPS basedon the Whetstone benchmark. More information can be found on
http://boinc.berkeley.edu/wiki/Computation_credit
3 Disaster Monitoring Constellation
http://en.wikipedia.org/wiki/Disaster_Monitoring_Constellation

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The Group for Earth Observation

GEO Quarterly No 37

Paul White
By the late 1960s, the use of satellites to look at the weather
was increasingly common, but the technology itself was stillin its infancy. Even by the end of the Apollo era, there werestill many experiments designed to determine whether datafrom satellites were as reliable as those from traditional
ground and atmospheric measurements.
Early satellites were launched with a life-span of just a few
months, and their images were examined on their returnto Earth. These included the early Soviet Kosmos satellites
as well as American efforts. Advances in communication
techniques later allowed signals from an orbiting satellite to
be sent back to a receiving station on Earth, where they could
be translated into photographic images.
Although primitive by present standards, the absenceof modern circuit board, micro-chips and programming
techniques meant that satellite developers had to cram alarge amount of complex, bulky, interconnected mechanicalworkings into a relatively small space. Ingenious solutions
were arrived at to achieve simple aims, such as using
electromagnets that would align with the Earth’s magnetic
field in order to maintain a satellite’s orbital attitude.
Two basic types of satellite orbit are discussed in this article:
geostationary and geosynchronous. Geostationary satellites
are placed in a position above the Earth that allows themto observe the same features on the ground at all times.
Geosynchronous satellites orbit the planet in such a mannerthat they pass over the same place on the ground at roughly
the same time every day. They are effectively always following
the same path, but the rotation of Earth underneath themmeans that each time they return to a specific point in theirorbit, they are over a different part of the planet.
Images from a number of different types of satellite will be
described: ATS, ESSA and Nimbus.
ATS
ATS stands for Application Technology Satellite, of which fivewere launched between December 1966 and August 1969.
Unfortunately, three of these craft failed and only ATS-I and
ATS-III returned useful data. The description that follows
applies to ATS-III, by far the most successful, returning usefuldata for eight years [1] (figure 2).
ATS-III was launched on November 5, 1967 and placed inhigh Earth orbit (HEO) at an altitude of 36 000 kilometres,in a position above the equator that allowed observation of
the American, African and European continents. Its primary
aim was to investigate new ideas in satellite photography,
meteorology, and communications technologies, and a totalof eleven experimental functions were on board. Although
the satellite was launched by NASA, the experiments it ran
involved collaboration with a number of other countries, aswell as academic institutions and private companies
The camera used to image the Earth was developed by
Dr Verner Suomi of the University of Wisconsin-Madison’sSpace Science and Engineering Centre, and is shown infigure 1. While in orbit, the satellite spun at around 120 rpm,
and with each spin scanned a narrow line representing
3.2 km of latitude on Earth’s surface. On the next spin it
scanned a slightly lower latitude and, over 2400 revolutions,
it would achieve full coverage. It took roughly 20 minutes to

Figure 1 - The ATS-III Multi-colour Spin Scan Cloud Camera system
Image: NASA ATS Image Collection

Les Hamilton

Paul White is the author of Clouds Across the Moon, a book inwhich he makes extensive use of contemporary weather satellite
imagery to disprove the claims of those who insist that America
never sent astronauts to the moon, claiming that the evidence
for the lunar landings was faked. The main thrust of his work,
available as an eBook in PDF format, is the comparison ofnumerous photographs displaying the Earth—made by Apollo
mission crews—with weather images taken by some of the early
Earth orbiting satellites.
Whatever your personal feelings on that particular issue,
Chapter 2 of the book should resonate strongly with all GEO
Quarterly readers. This section deals extensively with the historyof the earliest, pre-NOAA, weather satellites, and is probably themost comprehensive exposé available on the ATS, ESSA and
Nimbus craft. The text contains many illustrations, and numerous
links to images and relevant documents on the Internet. In short, if
you are at all interested in the story of weather satellites from theearliest days, this is the book for you.
There is also a chapter dealing with the photographic cameras
used by Apollo astronauts, but the main thrust of the book, thecomparisons between Apollo photographs of Earth and satellite
images, takes up most of its 600 pages, and a fascinating story
it is. Almost every page is illustrated with colour photographs andsatellite images, many of which are provided with links throughwhich you can download the original copies, if desired.
Clouds Across the Moon is a book you can dip into and enjoyat leisure, a little at a time—perhaps not to be read from end to
end in one go. I found it absolutely fascinating, and thoroughly
recommend it. You can download Clouds Across the Moon as a
149 MB PDF document, from Paul White’s website at
http://onebigmonkey.comoj.com/obm/catmall.html

where there is also a link to a web-based version of the book.

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Figure 2 - Artist’s depiction of ATS-III in orbit

Figure 3 - Verner Suomi

Image: NASA

Image: University of Wisconsin-Madison, Madison.

Figure 4 - An ATS-III colour image of Earth received at 15:31 UT on November 10,1967
Image: Space Science and Engineering Center (SSEC), University of Wisconsin-Madison, Madison.

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compose an entire image, after which the camera would reset
itself and the process would start anew.
GEO Readers may recall that the latest NASA/NOAA
satellite was named Suomi-NPP as a tribute to Dr Verner
Suomi (figure 3) and the work he carried out in this field.
Each colour image comprised a blue, green and red channel.
Unfortunately, these three channels worked for barely threemonths before the red and blue channels ceased to function,
though monochrome images were still being produced
until the mid 70s. At the time, this revolutionised satellite
meteorology. The frequent transmission of images changedhigh altitude cloud photography from interesting ‘after
the fact’ imagery to almost real-time imaging; this allowed
meteorologists to see weather systems as they developed
and predict more accurately how they were likely to behave.
The additional experiments on board the satellite allowed
cloud movements to be tied in with observations of otheratmospheric conditions, as well as ground-based readings,
and investment in satellite technology and meteorology
increased significantly.
ATS-III became the first satellite to photograph the full Earthfrom space in high quality colour (figure 4), and this led to
the first colour time lapse film of the Earth from space, which
can be viewed at this URL

GEO Quarterly No 37

these could store 70 images, roughly a day and a half’s worthof data. It took an estimated four hours between transmission
from the satellite until an image became visible on a terminalon the ground.
Verner Suomi set out to derive quantitative measurementsof winds based on cloud motion as depicted in successive
ATS-III images. Early efforts were laborious affairs, andinvolved printing out each image strip using characters suchas ‘*’, ’/’ and ‘)’ to simulate a greyscale. These printouts werethen pasted together to create huge images measuring up
to 100 square metres in area [3]. Cloud motion was thendetermined using a cross-correlation algorithm to determine
the cloud displacement in successive images.
Later, a computer-based video system caller WINDCO wasdeveloped. This used an instant replay analogue disk which
supported image animations and allowed the operator totransfer the location of clouds in each image on to paper tape(figure 6). After a further transfer to punched cards, this data
was submitted to the university’s Univac 1108 mainframe
computer, which output cloud displacement vectors, plotted
over a map of the Earth.

http://www.youtube.com/watch?v=KCIH6RVlHaw

Interestingly, ATS-III possessed a direct link with theApollo moon landing missions by providing real-time
TV transmissions for broadcasting by Radio Caracas in
Venezuela [2]. It is important to note that ATS-III served purely
as a relay for these TV signals. It took approximately half anhour for the satellite’s own camera to create a single image
and reset itself, and it did not have the capacity to broadcast
even its own images live. It would also not have been possible
for Apollo 11 to send a signal direct to the satellite as it
would not have been visible at the time. The main TV signal
for Apollo 11’s moon-walk (Extra-Vehicular Activity, or EVA)
was received by stations in Australia and transmitted by thecommunications satellite Intelsat to Houston, after which it
was relayed to the rest of the world.
ATS-III broadcast its signal to Earth over VHF frequencies,
which were received on VHF antennas of various types, as
illustrated in figure 5. The analogue signals from ATS-III werethen digitised, different levels of brightness being assigned
numerical values which were stored on tape for later analysis,
but the systems were bulky and slow.
According to NASA, a single digitised ATS image could use
up an entire tape reel (and four reels for a colour image).
Ultimately, seven-track 18-inch reels came into use, andFigure 6 - An operator at the WINDCO terminal
Image: SSEC, University of Wisconsin-Madison

ESSA
Environmental Science Services Administration launched
the ESSA series of 2nd generation TIROS (Television Infrared
Observation Satellites) probes through the 1960s [4]. Thesesatellites tended to be rather short-lived, with working
lifetimes of between one and three years (figure 7).
These probes were geosynchronous polar-orbiting satellites,
operating at a much lower orbital altitude of around
1400 km, and taking roughly two hours to complete eachorbit. They covered the entire Earth’s surface in 24 hours.
The satellite’s twin cameras were mounted at 180° to eachother along the side of the cylindrical craft, and as thesatellite cartwheeled in orbit, the camera facing the groundwould take an image. Mosaics of these images were madeon a polar stereographic projection, centred on the poles, forboth the northern (figure 8) and southern hemispheres.

Figure 5 - Antennas used to receive ATS III
Crossed dipoles with reflector (left), Crossed YAGI
(upper right) and a 3-turn helical antenna (lower right).

The ESSA satellites carried the Advanced Vidicon Camera
Systems (AVCS) [5] to image the Earth, and also a tapewww.geo-web.org.uk

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March 2013

Figure 7 - ESSA-1 undergoing moment of inertia testing
Image: NASA

recording system for storing the data for later transmission
to receiving stations. The exact coverage would varydepending on the altitude of the satellite in its somewhat
elliptical orbit, but each individual image covered an arearoughly 1200 kilometres square, where each line of the TV
transmission spanned close on three kilometres. The orbital
periods were designed so that the images were recordedin daylight, effectively meaning that photographs weretaken during one hour of each orbit. One image was taken
roughly every 260 seconds, with an exposure time of around8 seconds. A diagram showing the orbital paths for ESSA
satellites is shown in figure 9. These paths were the same foreach ESSA satellite.

Figure 8 - A typical ESSA northern hemisphere composite image
Image: NOAAInterestingly, the odd- and even-numbered ESSA satellites
transmitted their images to Earth in completely different
ways. ESSAs 1,3,5,7 and 9 recorded all their images bymeans of on-board tape recorder and stored them onmagnetic tape. Later, when the satellite was orbiting within
range of one of ESSA’s two ground receiving stations—in
Virginia and Alaska—these images were transmitted to Earth.
The received images were recorded on photographic filmusing kinescopes, and also transferred to magnetic tape,with numerical values used to represent different levelsof brightness. These tapes were used in ‘high powered
computers’ (sic), to create images that could be displayed oncathode ray computer monitors and transmitted by fax toother agencies throughout the world.
On the other hand, ESSAs 2,4,6 and 8 provided directtransmission of their data to ground stations around theworld by Automatic Picture Transmission (APT) immediately
after acquisition [6]. Although it took the camera only about
eight seconds to acquire each photograph of the Earth, it took
the APT system 352 seconds (almost six minutes) to transmit
each image, which covered a 1200 x 1200 kilometre areawith a spatial resolution of approximately three kilometres.
Eventually, there were over 300 APT receiving stations
located around the world, and the images were immediately
available to anyone capable of building a receiver. For the
first time, amateurs could collect images, and the website
for Douai Abbey [7] mentions that Benedictine monks at thisEnglish Abbey produced satellite images by recording theirsignals using radio receivers (although it is not clear to whichsatellite they specifically listened).
NimbusAt the same time as the ESSA program of active
meteorological satellites, Nimbus satellites were being
launched as research and development tools to test out new
atmospheric sensing techniques, and pioneered the AVCS

Figure 9 - ESSA satellite tracks
Image: NOAA

Figure 10 - An artist’s impression of Nimbus-1 in orbit
Image: NOAA

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GEO Quarterly No 37

Figure 11 - Nimbus data flow and processing.
Redrawn from a diagram originally published in Flight magazine, November 30, 1961.

and APT techniques used in ESSA satellites.
They had a secondary mission of providing
useful meteorological data [8]. Figure 10 comesfrom a NASA painting featuring Nimbus-1
orbiting the Earth.
Like ESSA, the Nimbus satellites were polar
orbiting geosynchronous craft, but they
orbited somewhat lower than the ESSAs ataround 800 kilometres, and each orbit wascompleted in less than two hours. Whilst
ESSA used two cameras, Nimbus satellites
had three, one pointing straight down and theother two angled at 35° on either side so that,
despite the lower orbital altitude, considerable
ground coverage could be achieved.
Each line of AVCS imaging [9] equated to justover a kilometre, a complete image required
six seconds to take, and successive images
were taken 90 seconds apart. The threecamera array produced a composite picture
covering an area of 830 x 2700 kilometres.
In parallel with the AVCS system, APT was
also used [10]. Images retained on the photosensitive surface of the vidicon were readout at four lines per second to produce an
800-line picture. A 5-watt TV transmitterthen relayed these to APT ground stations on
136.95 MHz. Each image measured 1660 km
square and has a resolution of 3 km. Each
image was stored electrically on a plate andFigure 12 - A single orbital pass transmission from Nimbus-3
Image: NASA/GSFC

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readings from the plate were transmitted to Earth. The
complete imaging cycle took just under four minutes tocomplete.
Figure 11 illustrates schematically how the Nimbus satellite
data was transferred, collected and distributed. Nimbus
images were available to anyone with a suitable decoder,and NASA’s history web page [11] reports the uses to which
European meteorological agencies put the data.
The VHF signals sent by the satellite were received by thesame type of dipolar antennas as ESSA transmissions, andwere processed in the same way as ESSA signals. Figure 12
shows a single orbital transmission from May 24, 1969.
Summary
Satellites orbiting the Earth in the 1960s were engaged indata collection for meteorological agencies not just in the
USA but worldwide. They operated slightly differently totoday’s craft in that they all used cameras that scanned
the Earth and recorded the images on magnetic tape. Data
from these tapes were transmitted to ground stations, either
automatically or on demand, using VHF signals. Receiving
stations recorded these signals and converted them to
TV images, which were photographed using kinescopes.
These images could then be sent over fax networks, andparticipating countries could record images directly.
NASA used satellite imagery to work out forecasts for launchdates for their Apollo missions, and also for the landing
areas after re-entry. They also used the satellite images tohelp determine what the astronauts described from theirview in space. Satellite imagery and other forecasts were
supplied by ESSA, who also worked closely with othergovernment agencies, including the Department of Defense.

References
1 NASA ATS Mission Page
http://science.nasa.gov/missions/ats/
2 ATS Mission Archive
http://www.nasa.gov/centers/goddard/missions/ats_prt.htm
3 McIDAS: 25 Years of Interactive Processing
http://www.ssec.wisc.edu/mcidas/software/mcidas25_bams.pdf
4 NASA ESSA Mission Page
http://science.nasa.gov/missions/essa/
5 Advanced Vidicon Camera System
http://nssdc.gsfc.nasa.gov/nmc/
experimentDisplay.do?id=1966-008A-01
6 ESSA 2 APT System
http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1966-016A-01
7 Douai Abbey Website
http://www.douaiabbey.org.uk/wilfrid.htm
8 NASA Nimbus Mission Page
http://science.nasa.gov/missions/nimbus/
9 Nimbus Advanced Vidicon Camera System
http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1964-052A-01
10 Nimbus APT System
http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1964-052A-02
11 NASA History
http://history.nasa.gov/SP-168/section1.htm

Editor’s Note
Readers wishing to pursue an interest in these early satellites
will find a wealth of links in ‘Clouds Across the Moon’ toadditional information not covered in detail above. These also
include catalogues of ESSA and Nimbus imagery.
Readers interested in sampling some of the coloured
ATS-III images will find a collection spanning the period
November 8, 1967 to January 24, 1968 at the following URL
http://library.ssec.wisc.edu/spinscan/images/

This visually spectacular, compact Atlantic depression heading for the UK was imaged by NOAA-19 at 13:39 UT
on January 30, 2013. This APT channel 2 image was captured using WXSat, and processed with SatSignal.

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GEO Quarterly No 37

A NASA Earth Observatory Report
Text adapted from Melt Pond ‘Skylights’ Enable Massive Under-Ice Bloom in the Arctic by Rebecca Lindsey, NOAA ClimateWatch Magazine

Wrangell Island and the Chucki Sea as viewed by Aqua on July 10, 2011.

A plot of chlorophyll levels (due to plankton blooms) in the same region, as detected by

For much of the winter, the sun barely rises over the Arctic Circle.
In mid-winter, it doesn’t rise at all. Most of the Arctic Ocean iscapped by ice, and beneath this, phytoplankton—the microscopic,
photosynthesising organisms that underpin the entire ocean foodweb—take a “long winter’s nap”. But when sunlight returns in thespring and the ice retreats, it’s like a cover being drawn off the roofof a greenhouse. The water along the edge of the retreating ice
explodes with blooms of phytoplankton.
The images above offer two views of a phytoplankton bloom in
the Chukchi Sea, northwest of Alaska, as imaged by the MODIS
instrument aboard NASA’s Aqua satellite on July 10, 2011.
The upper image is a natural colour view while the lower one isa plot showing the concentration of phytoplankton in milligrams
per cubic meter of seawater. Blue indicates areas with low
concentrations of chlorophyll, and yellow indicates areas with highconcentrations; land is light gray, and areas where MODIS could
not collect data due to clouds or sea ice blocking the satellite
sensor’s view are dark gray.

on July 10, 2011.

North of Wrangel Island, the sea ice has a dingy look in the natural
colour image. Although this could result from sediment, its distancefrom shore—plus the fact that the ice is fringed by waters withextremely high levels of chlorophyll—suggests that the ice has
been discoloured by algae and other phytoplankton.
According to Arctic oceanographer Karen Frey, the discolouration isconsistent with an unusual phenomenon that she encountered whileon a research cruise in the Chukchi Sea in July 2012: a massive
bloom of phytoplankton stretching some 100 kilometres beneath theice-pack. Historically, the ice in this area had been thick enough,even in spring, to keep the waters beneath in darkness. But in thepast decade ice conditions have changed dramatically, leaving athinner ice cover laced with shallow ponds of meltwater. These
ponds act like skylights, allowing light to filter through and support
phytoplankton blooms beneath the ice.
—————
NASA Earth Observatory images created by Jesse Allen, using MODIS data from the Land
Processing Distributed Active Archive Center (LP DAAC).

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GEO Quarterly No 37

The Group for Earth Observation

March 2013

A NASA Earth Observatory Report

The scenes of devastation and wreckage left behind by
Hurricanes Sandy (2012) and Katrina (2005) were tragicallysimilar. Both storms flooded major cities, cut electric power tomillions and tore apart densely populated coastlines. But from a
meteorological perspective, the storms were very different.
Katrina was a textbook tropical cyclone, with a compact,
symmetrical wind field that whipped around a circular lowpressure centre. Like most tropical cyclones, Katrina was a
warm-core storm that drew its energy from the temperatewaters of the tropical Atlantic Ocean. Sandy exhibited similar
characteristics while blowing through the tropics but, as thestorm moved northward, it merged with a weather systemmoving in from the west and started to make the transition into
an extratropical cyclone.
The two names sound similar, but there are fundamental
differences between these two types of storm. While tropical
cyclones draw their energy from warm ocean waters,
extratropical cyclones are fuelled by sharp temperature contrasts
between masses of warm and cool air. Extratropical cyclones
also tend to be asymmetric, with broad wind and cloud fields
shaped more like commas than circles. So, when a tropical
cyclone becomes extratropical, its wind and cloud fields expand
dramatically. The strongest winds generally weaken during thisprocess, but occasionally a transitioning storm retains hurricane
force winds: such was the case with Sandy.
The two wind maps on this page illustrate some of thedifferences between Katrina and Sandy. The map of Sandy’s
winds (figure 1), produced using data from the radar
scatterometer flying aboard the Indian Space Research
Organization’s Oceansat-2, shows the strength and direction of
Sandy’s ocean surface winds on October 28, 2012. The map ofHurricane Katrina’s winds (figure 2), shown to the same scale,
was created from similar data acquired on August 28, 2005 by

Figure 1 - Hurricane Sandy in 2012

the radar scatterometer aboard NASA’s QuickSCAT [1] satellite,
which ceased operation in late 2009. In both maps, windspeeds above 65 kph are shown in yellow, above 80 kph inorange and those above 95 kph as dark red (figure 3).
The most noticeable difference is the extent of the strong
wind fields. For Katrina, winds above 65 kph stretched about
500 kilometres from edge to edge of the storm; for Sandy,
winds of that intensity stretched a full 1,500 km.
Katrina’s winds were more intense, but they covered less area,with the result that Katrina’s storm surge as the hurricane
impacted New Orleans was, locally, higher than Sandy’s. But
because of its sheer size, Sandy caused its destructive surge
over a much longer stretch of coastline.
Another difference between the two storms was the locationof the strongest winds. For tropical cyclones in the northernhemisphere, and Hurricane Katrina was typical, the strongest
winds are usually located just east of the central eye, amidst aring of violent thunderstorms called the eye wall.
In the case of Sandy, however, the weakest winds were foundto the east, which strongly suggested that the storm had alreadybegun interacting with the weather system to its northwest anda blocking high over Greenland to its northeast.
References
1 QuikSCAT: NASA’s Eyes on Ocean Winds - GEOQ 9, p.26 (2006)

Figure 3 - Windspeed in kilometres per hour
Data courtesy of the Jet Propulsion Laboratory’s QuikSCAT and
the Indian Space Research Organization OceanSat-2 missions.

Figure 2 - Hurricane Katrina in 2005

38

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March 2013

The Group for Earth Observation

GEO Quarterly No 37

A NASA Earth Observatory Report

Australia’s largest and most frequent bush fires occur inspringtime, in the tropical savannas of northern Australia. On
November 25, 2012, the MODIS instrument aboard NASA’s Aqua
satellite captured this natural-colour image of wildfires burning on
Cape York Peninsula, the northernmost part of Queensland. Smoke
plumes from multiple fires are visible streaming to the west.

On Cape York Peninsula, the dry season arrives in March and,by late November, grasses and woodland trees are at their mostflammable. In this case, steady 20 kph winds have helped tosustain fires that were probably started by lightning and humanactivity.
NASA image courtesy Jeff Schmaltz, LANCE Rapid Response Team at NASA GSFC.

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GEO Quarterly No 37

The Group for Earth Observation

March 2013

A NASA Earth Observatory Report

The Peary Channel separating Melville Island and Victoria Island is choked with ice on July 17, 2012.
NASA image by Jesse Allen, using data from the Land Atmosphere Near real-time Capability for EOS (LANCE).

Just over two weeks later, the Peary Channel appears largely ice-free on August 3, 2012.
NASA image by Jesse Allen, using data from the Land Atmosphere Near real-time Capability for EOS (LANCE).

Ice retreated rapidly in the Parry Channel,
part of the famous Northwest Passage,
between mid-July and early August 2012.
These images, acquired by the Moderate
Resolution Imaging Spectroradiometer(MODIS) on NASA’s Terra satellite, show
significant changes over two weeks. The
top image shows Parry Channel chokedwith ice on July 17. The lower image shows
the same region on August 3, when open
water dominated the scene, with only
remnant ice still clinging to the shores ofVictoria and Melville Islands. On July 30, ice
cover was roughly 33% compared with thelong-term median of 79%.

40

However, thin sea ice can evade detection
by satellite sensors such as MODIS yet
still be thick enough to impede shipping so,while the Parry Channel appeared almost
entirely free of ice, it was not necessarily
open for navigational purposes. Close
examination of the image from early Augustdoes show lingering patches of ice south ofMelville Island.
Regardless of whether ships can easily
pass through it, recent studies suggestthat certain organisms have begun totake advantage of open water along theNorthwest Passage. A 2007 study on
Neodenticula seminae, a plankton species

www.geo-web.org.uk

historically endemic to the Pacific Ocean,discovered that the species had turned
up in the North Atlantic. The researchsuggested that the plankton’s route included
the Canadian Arctic Archipelago.
And a 2012 study on bowhead whales,
where individuals were tracked using
satellite transmitters, revealed that Pacificand Atlantic populations had begun tooverlap in the Northwest Passage as earlyas August 2010.

NASA Earth Observatory images by Jesse Allen, using
data from the Land Atmosphere Near real-time Capability
for EOS (LANCE).

March 2013

The Group for Earth Observation

GEO Quarterly No 37

A NASA Earth Observatory Report

On July 15, 2012, the Visible Infrared Imaging Radiometer Suite(VIIRS) on the Suomi NPP satellite captured this night time view of
the aurora australis over Queen Maud Land and Princess Ragnhild
Coast of Antarctica. The image was captured by the instrument’s
day-night band, which detects light in a range of wavelengths fromgreen to near-infrared. In the image above, the sensor detected thevisible auroral light emissions created by energetic particles raining
down from Earth’s magnetosphere into the gases of the upper
atmosphere. The slightly jagged appearance of the auroral lines isa function of the rapid dance of the energetic particles at the sametime that the satellite is moving and the VIIRS sensor is scanning.
The lower image is a close-up view of the region outlined by thebox in the upper image. Light from the aurora was bright enoughto illuminate the ice edge between the ice shelf and the Southern
Ocean.
NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS DayNight Band data from the Suomi National Polar-orbiting Partnership.

Suomi NPP is the result of a partnership between NASA, the National Oceanicand Atmospheric Administration, and the Department of Defense.

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GEO Quarterly No 37

The Group for Earth Observation

March 2013

Les Hamilton
This narrative starts in early 2002, when, with the Antarctic summer
at its height, the Larsen-B ice shelf underwent a catastrophic
collapse. Located on the eastern coast of the Antarctic Peninsula,this 3 250 square kilometre shelf of floating ice, 220 metres thick,completely splinteredinto fragments between
January 31 and March 7.
Ice shelf collapses had beenrecorded previously, butnever had such an event
been observed on this scale.

Based on studies of ice flow and sediment thickness beneath
Larsen-B, scientists believe that it had existed for at least 400 years
prior to this event, and, very probably, since the end of the last
major glaciation 12 000 years ago.

Figure 1, captured by the
MODIS instrument aboard
NASA’s Terra satellite on
January 31, hints at the startof the breakup. The ice shelf(in the centre of the image)shows parallel lines of blue
meltwater pools, arranged
thus because the water
was draining into existing
crevasses. Beneath a thinlayer of clouds, a smatteringof icebergs appears in thedark, open waters of the bay.
By February 23 (figure 2),
a number of long, narrowicebergs had fractured from the southern end of the shelf, andby March 7 the shelf had disintegrated into a mixture slush andicebergs that filled the bay and soon became locked into place by
new seasonal sea ice. Figure 3 shows the scene three years later
after the remains of the shelf had dispersed into the ocean.

42

Figure 2 - The Larsen B Ice Shelf on February 23, 2002
Terra MODIS Image: NASA

Figure 1 - The Larsen B Ice Shelf on January 31, 2002

Figure 3 - The same area on February 18, 2005

Terra MODIS Image: NASA

Terra MODIS Image: NASA

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March 2013

The Group for Earth Observation

The collapse of the Larsen-B ice shelf appears to have been due toa series of warm summers over the Antarctic Peninsula, culminatingwith an exceptionally warm one in 2002. Significant surface melting
due to warm air temperatures created melt ponds; these acted likewedges which deepened crevasses and eventually caused the shelf
to disintegrate. To give an idea of the actual scale of events, theoriginal ice shelf had an area approximately the same as the islandof South Georgia, and the mass of ice involved in the disintegration
was estimated to have been 720 billion tonnes.
The Larsen-B ice shelf exerted a buttressing effect which slowed
the advance of its fifteen tributary glaciers. But during the ten
years following the shelf’s disappearance, the flow of most of these
glaciers has accelerated significantly. The faster flow of the ice,

GEO Quarterly No 37

coupled with the calving of icebergs when it reaches the coast, hasresulted in the glaciers retreating inland. The total ice being lostfrom these ice streams is currently estimated to be of the order often billion tonnes per annum.
The Retreat of Crane Glacier
The most dramatic change has been observed at Crane Glacier,the longest of the Antarctic Peninsula’s glaciers, which flows eastnortheast for 50 kilometres through a deep trough into Exasperation
Inlet on the east coast. The speed of Crane Glacier has increased
threefold since the demise of the Larsen-B Ice Shelf, during whichtime its terminus has retreated by more than 12 kilometers.
The two images from NASA’s Landsat 7 satellite show how Crane
Glacier has retreated during the past ten years. Figure 4 was
captured on April 6, 2002, about two months after the dramatic ice
shelf collapse. The snout of Crane Glacier can be seen extending
into the bay like a fan, while the waters of the bay itself are chokedwith slush and icebergs from the collapsed ice shelf.
Throughout the summer of 2003, remaining fragments of the ice
shelf continued to broke away while the mélange of ice detritus
the previous summer’s collapse began to drift away. Without thestabilising presence of the ice shelf, Crane Glacier started to retreat
dramatically, its fan-shaped terminus becoming ‘C’ shaped as its
central region crumbled faster than its edges, the latter stabilised
through friction with their containing mountainsides.

Figure 4 - A Landsat-7 image of Crane Glacier on April 6, 2002
Image: NASA

The unusually bright blue tinge of the ice debris in the February 20
image (figure 5) results from reflections from the pure ice on theundersurfaces of the ice shelf fragments. Many of the icebergs
that crumbled from the edge of the shelf were too tall and narrow
to float upright, and they toppled over. The surface of an ice shelf
becomes covered by snow, but the underside is very pure ice which
absorbs a small amount of red light. Photo-like satellite images
such as these are made by combining the satellite’s observationsof red, green, and blue wavelengths reflected from the Earth’s
surface. When all these visible wavelengths are reflected equally,
the surface appears white; but when some of the red light has beenabsorbed, the reflected light takes on this cyan tinge.
Figure 6 is based on an image captured by the Advanced Land
Imager (ALI) instrument on the Earth Observing-1 (EO-1) satellite,with added outlines to illustrate the location of the terminus of
Crane Glacier in April 2002, February 2003, and February 2006.
The image actually dates from February 24, 2012, but remains
relevant because there has been no further retreat by the glacier
since 2006.
Sources
Collapse of the Larsen B Ice Shelf
http://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php

Figure 5 - Landsat-7 image of Crane Glacier on February 20,2003
Image: NASA

Larsen B Ice Shelf Collapse
http://earthobservatory.nasa.gov/IOTD/view.php?id=2351
Retreat of Crane Glacier
http://earthobservatory.nasa.gov/IOTD/view.php?id=43459

Figure 6 - The Retreat of Crane GlacierNASA Earth Observatory image created by Jesse Allen and Robert Simmon,using EO-1 ALI data provided courtesy of the NASA EO-1 team.

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The Group for Earth Observation

March 2013

Dear Francis,
I just wanted to drop you a note toaddress a few items you raised inyour last GEO Report. I’m a recent
re-subscriber. I couldn’t tell you
when I lapsed, but It pretty much
was just down to running out ofhours in the day, and my focus being
elsewhere.
On January 21, 2013, Meteosat-10 took over from
Meteosat-9 as EUMETSAT’s prime operational
geostationary weather satellite, after being moved
to 0º. Launched on 5 July last year as MSG-3,
this latest Meteosat Second Generation satellite
now provides the operational weather and climate
monitoring service over Europe and Africa. Meteosat-9
has been drifted to the 9.5°E slot where has taken overthe Rapid Scanning Service (RSS) from Meteosat-8,
following its short spell of parallel dissemination withMeteosat-10. Meteosat-8, now drifted to 3.5°E, is theoperational backup for Meteosat-10 (and if need be,also for Meteosat-9).

Shortly after the severe 2010/2011
winter, I treated myself to a new
Davis Vantage VUE Weather Stationand got it mounted properly in
November 2011. This was more tosatisfy more my own curiosity.
Meeting you (and the gentleman withyou), along with the fantastic qualityof your publications, re-kindled
my interest. I also re-activated my
EUMETCast ftp download account,

Meteosat-9 and -10 now form the two-satellite
configuration, where Meteosat-10 provided full disc
imagery of the European and African continents andadjacent seas every 15 minutes while Meteosat-9
delivers the more frequent RSS images every fiveminutes.

continued from page 2

September 9-13, 2013
The European Space Agency (ESA) are
holding a symposium ‘ The living Planet’ in
Edinburgh. GEO will be requesting spacein the ‘Poster Exhibition’ area where will
display visual materials relating to GEO’s
activities together with informative leafletsfor delegates.
September 13-15, 2013
The Royal Meteorological Society areholding their second amateur conference at
Reading University. At the first conference,
GEO gave a presentation to the meetingand had a display stand running live
EUMETCast reception. We have offered tomake a similar contribution this year. The
conference should be of interest to anyone
interested in climate and weather. For full
information visit
http://www.rmets.org/events/
rmets-amateur-conference-2013

September 27-28, 2013
The National Hamfest which is held on the
Newark show ground. This is a busy two
day event and GEO will have a display
stand in the main exhibition hall.

44

www.geo-web.org.uk

and I’ve a bunch of (fairly poor, it mustbe said) scripts that automatically pullin the 30-minute LRIT files, which I
process for viewing later. Also, I’m
hoping to get my RTL-E4000 SDR
back from an extended loan, and I
think I’ll try using it for APT reception.
Unfortunately, I don’t think I’d get
permission from the wife to put up myown dish for direct reception. That said
though, how difficult would it be to add
an LNB to our existing sky dish?
Lastly, should you consider going
down the road of a PDF-only
subscription, I would be interested intaking you up on it.
Regards
John Ronan, EI7IG

March 2013

The
T e Group for Earth ObservationTh

GEO Quarterly No 37

Ukraine’s Sich-2 satellite imaged Lake Mead, the largest reservoir in the United States on September 16, 2012. Stretching for
180 kilometres behind the Hoover Dam on the Colorado River, the reservoir can hold 34 cubic kilometres of water when completely filled.

Sich-2 captured this spectacular image as it flew over Antarctica on September 9, 2012. The precise location of this image is
unknown, but the low angle of the sun highlights the mountains and glacier to the right of the image in spectacular fashion.
Images © Dniprokosmos

www.geo-web.org.uk(www.dniprokosmos.dp.ua)

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GEO Quarterly No 37

EUMETCast On-Line
Registration Guide
If you require to register as a first-time user for
any of the free EUMETCast data streams suchas MSG, NOAA AVHRR, Metop etc, or needto renew an existing subscription, this must be
done on-line.
GEO has produced a step-by-step guide to theentire process at
http://www.geo-web.org.uk/eumreg.html
This guide also contains a direct link to theofficial EUMETCast on-line registration form,
which can otherwise prove somewhat tricky tolocate.

GEO Helplines
Douglas Deans
Dunblane, Perthshire, SCOTLAND.

All aspects of weather satellites from APT,
HRPT to Meteosat-9 DVB/EUMETCast
systems.
• telephone:(01786) 82 28 28• e-mail: dsdeans@btinternet.com
John Tellick
Surbiton, Surrey, ENGLAND.
Meteosat-9 advice: registering for the various
MSG services, hardware and software
installation and troubleshooting. John will
also field general queries about any aspect ofreceiving weather satellite transmissions.
• telephone: (0208) 390 3315
• e-mail: info@geo-web.org.uk
Geoff Morris GW3ATZ
Shotton, Flintshire, NE WALES.
Geoff has lots of experience with aerial,coax,connectors, mounting hardware etc. andhas also done a lot of work with the orbiting
satellites. Geoff has been a EUMETCast
Meteosat-9 user for some time and is familiar
with David Taylor’s MSG software. He
should be able to share his experiences with
newcomers to this branch of the hobby.
• Tel: (01244) 818252• e-mail: gw3atz@btopenworld.com
Mike Stevens
Portland, Dorset, England.
Advice and assistance offered on EUMETCast(MSG, NOAA and Metop).
• email: mikeg4cfz@gmail.com
Guy Martin G8NFU
Biggin Hill NW Kent, ENGLAND
Guy is prepared to advise anyone who wishing
to receive MSG/Metop using Windows 2000 or
XP. Can also help with networking and ADSL
router setup.
• gmartin@electroweb.co.uk
Hector Cintron
San Juan, Puerto Rico, USA
Hector is prepared to field enquiries on HRPT,
APT, EMWIN and NOAAPORT• Phone: 787-774-8657• e-mail: n1tkk@hwic.net
Email contact can of course be made at any
time, but we would ask you to respect privacy
by restricting telephone contact to the period
7.00-9.00 pm in the evenings.

46

The Group for Earth Observation

Weather Satellite Reports
If there is a single Internet Forum that isrelevant to all weather satellite enthusiasts,
it must surely be Douglas Deans’ Weather
Satellite reports.
Here you will find every conceivable type of
information about weather satellites, whether
polar or geostationary, APT, HRPT, LRIT orwhatever.
Absolutely everything is covered, and theinformation is updated every week. Special
additional bulletins may be issued if an
important change takes place mid week.
You can read the bulletins from this URL
http://tech.groups.yahoo.com/group/
weather-satellite-reports/
or, even better, elect to have the reports sent
to you by email every Monday.

Internet Discussion Groups
There are a numerous 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 themore useful groups and their contact addresses
are listed below.
APT Decoder
This is a group where users of Patrik Tast’s
APTDecoder can share information andproblems.
http://tech.groups.yahoo.com/
group/APTDecoder/
GEO-Subscribers
This is GEO’s own group, where members can
exchange information and post queries relating
to any aspect related to weather satellite
reception (hardware, software, antennas etc),
Earth observation satellites and any GEOrelated matter.
http://tech.groups.yahoo.com/
group/GEO-Subscribers/
Satsignal
An end-user self help group for users ofDavid Taylor’s Satellite Software Tools(SatSignal, WXtrack, GeoSatSignal, HRPT
Reader, GroundMap, MSG Data Manager,
AVHRR?Manager and the ATOVS?Reader).
http://tech.groups.yahoo.com/
group/SatSignal/
MSG-1
A forum dedicated to Meteosat Second
Generation (MSG), where members share
information about the EUMETCast reception
hardware and software.
http://tech.groups.yahoo.com/
group/MSG-1/

www.geo-web.org.uk

March 2013

Copy Deadline for
GEO Quarterly No 38 isSaturday, April 27
The Editor is always delighted to receive
articles and images for inclusion in
GEO Quarterly. These can relate to any
aspect of Earth Imaging, especially• Technical articles concerning relevant
hardware and software• Construction projects• Weather satellite images• Reports on weather phenomena• Descriptions of readers’ satellite imaging
stations• Activities from overseas readers• Letters to the Editor• Problems and Queries for our experts toanswerContributions should of course be original
and, where possible, should be submitted
to the editor in electronic format (e-mailattachment, CD, DVD). But of course, wewould also accept handwritten or typed copy.
Please note, however, that major articles
which contain large numbers of satellite
images, photographs or other illustrations
should be submitted as early as possible,
so that they can be prepared and made up
into pages in time for publication.
Images and Diagrams
Images can be accepted in any of the
major bitmap formats: JPG, BMP, TIFF etc.
Images in both monochrome and colour are
welcome. Line drawings and diagrams are
preferred in WMF, EPS or postscript formats.
We can also scan original photographs,
negatives and slides.
Gridding, Overlays and Captions
Please note that satellite images should
be submitted without overlays such as
grid lines, country outlines and captions
unless these are considered essential for
illustrative purposes within an article.
If your article submission contains embedded
images and diagrams, please note that you
must also submit copies of the original
images in one of the formats describedabove: these are essential for page make-up.
Submission of Copy
Materials for publication should be sent to
the editor,
Les Hamilton
8 Deeside Place
Aberdeen AB15 7PW
ScotlandThe most efficient way to do this is by email
attachments to the following address
geoeditor@geo-web.org.uk
Particularly large attachments (8 MB andabove) can be transmitted via YouSendIt
www.yousendit.com_________________________

And finally . . .
When you have material ready for thefollowing issue of GEO Quarterly, pleasesubmit it as soon as it is ready—do not
wait till the deadline above: this will simply
create an editorial log-jam and delay
publication.

March 2013

The Group for Earth Observation

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March 2013

Envisat imaged West Africa, including Cape Verde, the Gambia and Guinea-Bissau with its offshore islands, on December 12, 2011.
Image © ESA

Envisat imaged the confluence of the White and Blue Nile rivers at Khartoum on November 23, 2011.
Image © ESA