Group for Earth Observation

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

56
December 2017
Inside this issue . .
This image is a clip from ahigh-resolution Feng Yun-3
transmission acquired—using home-brew
equipment—by members of
GEO’s Dutch counterparts,
Werkgroep Kunstmanen.
Inside this Quarterly, Rob
Alblas and Ben Schellekens
describe their project andencourage GEO members totake up the challenge withthem.
After long years of waiting,
the JPSS-1/NOAA 20
weather satellite waslaunched in mid November
and is currently undergoinga period of testing prior tobeing commissioned. You
can read about this newsatellite in our bumper
64-page issue.
We also have an illustrated
article from John Tellick,who discusses the incidenceof sunglint in satellite
images.
This past year saw an eventof major importance in
Antarctica when there wasa spectacular disintegrationof the Larsen C ice shelf.
Les Hamilton has compiled
a 6-page article that traces
this event from its historicalroots up to the present day.
And there are NASA Earth
Observatory reports on suchdiverse topics as Fires in
the Falklands, Algal Blooms
in Lake Erie, Lake
Balkhash, the shrinking
Ozone Hole, The Bosphorus
and the Aral Sea.

GEO MANAGEMENT TEAMLes Hamilton

Director and Public Relations
Francis Bell,
Coturnix House, Rake Lane,
Milford, Godalming, Surrey GU8 5AB,
England.
Tel:
01483 416 897
email: francis@geo-web.org.uk
General Information
John Tellick,email: information@geo-web.org.uk
GEO Quarterly Editor
Les Hamilton,
8 Deeside Place,
Aberdeen AB15 7PW, Scotland UK.
email: geoeditor@geo-web.org.uk
GEO Quarterly Despatch
Peter Green
Membership and Subscriptions
David Anderson,
35 Sycamore Road,
East Leake, Loughborough LE12 6PP,
England, UK.
email: members@geo-web.org.uk
Tel:01509 820 067
Technical Consultant (Hardware)David Simmons
email: tech@geo-web.org.uk
Webmaster and Website Matters
Alan Banks,e-mail: webmaster@geo-web.org.uk
GEO Shop Manager
Nigel Evans (Assistant: David Simmons),
email: shop@geo-web.org.uk
International Liaison
Rob Denton,
email: liaison@geo-web.org.uk
Management Committee Members
Clive Finnis
Carol Finnis

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,
Surrey GU8 5AB, England.
Printing (December Issue)
Hedgerow Print,
16 Marsh Lane,
Crediton, Devon EX17 1ES.
Tel: 01363 777 595
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 © 2017
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.

geoeditor@geo-web.org.uk

Since GEO Quarterly ﬁrst appeared in Spring 2004, the most notableomissions from its pages have been self-build projects for readers
as the near simultaneous rise of EUMETCast all but completely
quenched improvisation and invention. But at last, in our ﬁnal issue,
Rob Alblas and Ben Schellekens, members of the Dutch group Werkgroep
Kunstmanen, reveal how their efforts to develop a homebrew system for
capturing high-resolution imagery from Metop and Fengyun-3 satellites
has come to fruition. Hopefully some of our readers will follow in theirfootsteps and keep us informed via the GEO-Subscribers YAHOO Group.

It is also time to look back in time and reprise articles from two stalwartsof earlier days. I have chosen Cedric Roberts RIG article which provides
timely information about power surges—and what can go wrong if you
don’t protect against them. And we must not forget the roots of ourhobby, expressed by Ed Murashie in his illustrated essay on TIROS-I, thevery ﬁrst Earth imaging weather satellite.

F

inally, on behalf of the entire Management Team, thanks to all ourreaders, old and new, for supporting GEO over the years. Hopefully
we have helped you to maximise your enjoyment of our shared hobby of
weather satellite imaging. We will remain available to provide assistanceand answer queries via the GEO Subscribers YAHOO Group at
https://groups.yahoo.com/neo/groups/GEO-Subscribers/

and we leave a legacy of PDF copies of all 56 Quarterlies on our website asa reference source at
http://www.geo-web.org.uk/geoq_archive.php
Masthead Photograph - Aberdeenshire’s most famous mountain, Lochnagar

Contents
GEO Report
Quarterly Question
JPSS: The Joint Polar Satellite System
From the Editor’s Keyboard
Break-up of the Larsen Ice Shelves
Salar de Atacama
Receiving Satellites the Hard(?)ware Way
Fires in the Falkland Islands
Sunglint on Satellite Images
Lake Erie Abloom
End of the Iceberg Life Cycle
TIROS-I
Lake BalkhashLand Viewer Update
Coping when Nature Runs Wild
Weather Ready Nation
Salt Glacier in Iran’s Zagros Mountains
New Water in the Aral Sea
The Ozone Hole is its Smallest for nearly 30 Years
GOES-16 on the Move
Bridging the Bosphorus
Hurricane Ophelia and the UK’s Red Sun
Forty Years of Meteosat
Useful References for Reception from Satellites
Cover Image Details
Copernicus Online Data Access: Update
Satellite Status
GEO Helplines and Internet Discussion Groups
GEO Shop Catalogue and Price List

Francis Bell
Francis BellLes Hamilton
Les Hamilton
Les Hamilton
Les Hamilton
Rob Alblas / Ben Schellekens
NASA Earth Observatory
John Tellick
NASA Earth Observatory
NASA Earth Observatory
Ed Murashie
NASA Earth Observatory
Les Hamilton
Cedric Roberts M.B.E.
Ed Murashie
NASA Earth Observatory
NASA Earth Observatory
NASA Earth Observatory
Ed Murashie
NASA Earth Observatory
John Tellick
European Space Agency
Francis BellLes Hamilton

2
4
5
8
9
16
18
24
25
29
30
31
35
38
43
44
47
48
50
52
54
56
58
60
61
61
62
63
64

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Francis Bell
Although our group is undergoing some changes, our policy toretain the background structure of a limited company remains.
The Group for Earth Observation Limited, No. 4975597, wasestablished almost exactly 14 years ago to provide an umbrellaof responsibility for individual members in case of serious
mistakes or claims against individuals who were acting on behalfof the group. In such unlikely circumstance, the liability would
rest with the company rather than any individual. Fortunately, we
have never had such problems but we continue with the limited
company structure for legal background security. The runningcost is £15 for registration of directors which continues to bemyself as director and Mrs N Bell as company secretary. We
annually submit a summary of our accounts to Companies Houseand these are a matter of public record.
Because GEO did not hold its regular annual meeting last year,
no accounts were available to members. To ensure this does
not happen again this year, a summary accounts for the year
1st December 2016 to the end of November 2017 is set out inTable 1, from which it can be seen that we have just enoughmoney in our membership account to publish our planned
December printed Quarterly but almost nothing thereafter.
The shop account has a substantial balance due to the small
profits we have made over the years from sales. This money isa reserve which will keep GEO viable during the foreseeable
future or until we start requesting subscriptions again for GEO
membership. We do have some assets in the form of two
computers used at shows but as they are several years old theirmonetary value is almost zero.

Internet Inﬂuence over GEO Subscriptions
During the 14 years since GEO was established there have been
rapid changes in communication technology, with new material
being published almost instantaneously via the Internet, with aconsequent decline in printed paper material. GEO has been
engulfed with these changes to the extent that some of our own
Quarterly publications have been available solely in electronic
form via the Internet and our website.
Once the infrastructure has been established, there is a very
low cost to electronic publication, hence leading to the GEOManagement Team re-evaluating the necessity of asking for amember subscription. Since mid 2017 we have been accepting
renewals and new memberships but have not been asking for a
subscription. How viable such a policy is will only be revealed in
the long term; however, in the short term GEO renewals and newmemberships are welcome without a subscription.
Membership Matters
Please see the adjacent membership list as of July 2017
(Table 2). We will maintain our established registeredmembership, held by our membership secretary, which meansthat GEO still has the ability to communicate with them whenappropriate via email. For those members who joined more
recently—via the ‘GEO-Subscribers YAHOO Group’—we will beable to keep in touch electronically and post news on this forum,
together with our GEO website atwww. geo-web.org.uk
At a recent radio show at Kempton, I promoted GEO membershipwith a leaflet telling people how to join GEO, and the benefits ofmembership. The Text of this leaflet is shown opposite.

Table 1 - GEO Accounts for the year 2016-20172

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Free Membership of the Group for Earth Observation (GEO)GEO Shop

To join GEO and learn more about Earth Observation and related
topics, subscribe to the GEO-Subscribers YAHOO Group at

Almost every edition of our GEO Quarterly has contained a page
devoted to equipment available from our GEO shop. The shop
was started soon after the formation of GEO by Clive Finnis
supported by his wife Carol. Carol still looks after GEO’s PayPal
account.

https://groups.yahoo.com/neo/groups/GEO-Subscribers/info
and click on the ‘Join Group’ button. You will find that the benefits
of GEO membership include:• Advice and technical support about hardware and software
relating to the live reception of geostationary and polar
orbiting weather satellites.
• Advice about gaining free access to recent satellite Earthimages from EUMETSAT, ESA and NOAA plus the Russianand Japanese satellites.
• Access to our ‘GEO Shop’ ‑ but note that the future of theshop is uncertain.
• Invitations to join our annual meetings, which are typicallyheld at the National Space Centre, Surrey Satellite
Technology or EUMETSAT’s HQ in Darmstadt, Germany.
• Support for live satellite reception in schools or othergroups plus advice about displaying satellite images.
In return you can offer your own knowledge and experience ofEarth satellite reception, hence benefitting other members.

After a few years the shop facilities were taken over by Nigel
Evans assisted by his wife Michele. GEO is particularly gratefulto Nigel who, in recent years, has given GEO members access tosatellite reception equipment, particularly the SR1 receiver, which
would otherwise have been extremely difficult to purchase byindividuals in the UK.
In this particular case the receivers had to be imported from
Israel into the UK with advance payment of VAT, after which Nigel
then had to perform upgrades to the receiver’s software before
selling them to GEO members. Our sincere thanks to Nigel
for his time and technical skills in making a range of satellite
reception equipment available to our members which mightotherwise have been difficult to buy elsewhere.

Once you have joined, you can look in more detail at the people
who have been using this site and their messages by visiting theabove URL and selecting ‘Conversations’ from the menu. You will
also find references for posting your own messages.
GEO Subscribers is subject to rules, and moderated by membersof GEO’s Management Team.
The number of people currently registered on the Yahoo User
Group is 865. It is difficult to assess, but some of these people
will be casual users of the site but a substantial number could beconsidered GEO members.
Annual Meeting
Members will have noticed that we missed our annual meeting
this year, thus making a meeting in 2018 more attractive thanusual. No decision has been made relating to a 2018 meeting but
the idea is to combine our meeting with a visit to EUMETSAT’s
HQ in Darmstadt Germany. We have visited Darmstadt before in
2007, 2011, and 2015 with these events also incorporating visits
to nearby ESOC .
Personally I would be delighted if there were support for aDarmstadt visit, which would give us the opportunity to bebrought up-to-date with developments relating to EUMETSAT
and ESA satellites, and the dissemination of Earth images.
Additionally, a visit to their expanding on-site computer storage
facilities would be great. Perhaps more important than thetechnical parameters of a visit would be the opportunity to meetagain the friendly and helpful staff at EUMETSAT’s Ops. Help
Desk.
If there is support for a visit to Darmstadt, I suggest a date close
to July 5, 2018 with an ESOC visit the following day. Note that
this is just a suggestion and nothing has been booked or agreed
with EUMETSAT or ESOC. If you think you would like to attend
such a visit please let me know by email, as soon as possible, tofrancis@geo-web.org.uk.
An alternative to the above suggestion could be to hold ourmeeting at the National Space Centre, Leicester, as we havedone several times in the past.
In either case there would be no charge to delegates forattendance but individuals would have to cover their own
personal expenses.
Table 2 - GEO Membership Breakdown

www.geo-web.org.uk

3

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Francis Bell

Photo credit: Tim Peake / NASA / ESA

Quarterly Question 55
My thanks to those members who responded to the last Quarterly
Question, which related to the Earth’s overall sea level. We are
told by the scientific community that Earth’s sea level is rising
significantly due to the melting of the ice: principally the Antarctic
and Greenlandic ice caps. The Quarterly Question asked what
or where, is the absolute reference for worldwide sea level fromwhich any changes can be measured.
Unfortunately, those members who responded to the question
only quoted the land height reference for the UK. This is areference point in Newlyn, Cornwall, defined by the UK’s
Ordinance Survey many years ago when surveying the wholecountry. I believe this is still the reference level used today but I’m
not sure about any level calculation which is needed to recognisethat the UK is located on a curved surface, that is, the surface of
the Earth which is a sphere. I’m sure someone will be able to tellme. If anyone knows about such a world-wide reference for sea
level measurements perhaps you could write a paragraph or twoand send it to our editor or myself.
Quarterly Question 56
This Quarterly Question relates to a photograph taken by the
UK’s astronaut Tim Peake during his six month stay on theInternational Space Station just over a year ago. The photograph,above, shows a large city with a population in excess of fifteen

4million people, very slightly to the left of centre. The question isstraightforward: ‘Give the name of this ancient city shown in
the photograph’.
It is worth noting that the photograph may have been takenusing a hand-held camera, hence the view might not have theresolution of a dedicated onboard instrument. However, the main
geographical features shown should enable you pick the area of
the Earth where the photograph was taken and hence identify thecity in question.
Note that the scale of the photograph is about 30×50 kilometres.
Because the photograph is likely to have been taken by apersonal camera, the recorded image is likely to be in the visible
colour light spectrum. The orientation of the photograph shows
north at the top. The main clue to the area photographed is thearea of water shown at the bottom of the photograph, this called
the Sea of Marmara.
As usual I take extra interest in these photographs and Earthimages if they shows somewhere I have visited—which is again
the case with this photograph. I spent one day in this city andvisited three mosques but not the golden one!
Please send your answers to francis@francisbell.com
before the end of February 2018.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Les Hamilton
The JPSS-1 satellite lifted off from Vandenberg Air Force
Base, California, at 9:47 UT on November 18, 2017, andbe renamed NOAA-20 when it reaches its final orbit.
Following a three month period during which the satellite’s
instruments will be tested and calibrated, scientists andforecasters will be able to utilise the it’s data officially. The
satellite is designed to operate for a minimum of sevenyears, with the potential for extended operation for several
more years thereafter.
The data NOAA 20’s advanced instruments provide will
improve weather forecasting: such as predicting hurricane
tracks and helping to recognise climate patterns that can
influence the weather, such as El Niño and La Niña. They
will also help emergency managers to respond to events
such as wildfires, floods and volcanic eruptions, as wellas helping communities to recover from severe weather by
providing better images of the damage.
It’s more than eight years since NOAA 19, the final satellite
in the Polar Orbiting Environmental Satellites (POES) series,
was placed in orbit. This satellite continues to disseminate
AVHRR imagery well past its design lifetime of five years,
as do NOAA 18, launched in 2005 and NOAA 15 which willcelebrate 20 years in orbit on May 13, 2018.
It was originally planned to follow the POES fleet with a
new generation of environmental observation satellites
to monitor Earth’s weather, atmosphere, oceans, land,and near-space environment: the National Polar-orbiting
Operational Environmental Satellite System (NPOESS). Thiswas proposed to replace and amalgamate both the UnitedStates Department of Defense’s DMSP satellites and thecivilian NOAAs, with the first launch projected for around2013. But issues with sensor developments resulted in a
succession of delays, sending the project well over budget,and the White House pulled the plug on it early in 2010,
deciding instead to continue with a bipartite military/
civilian system.
The new NOAA/NASA (civilian) project became the Joint
Polar Satellite System (JPSS), and a fixed price contract of$248 million for the JPSS-1 spacecraft was agreed with
Ball Aerospace & Technologies Corporation. The Defense
Department’s project was called Defense Weather Satellite
System (DWSS), but this was cancelled by the US Air Forcein 2012.
The JPSS is developed by the National Aeronautics andSpace Administration (NASA) on behalf of the National
Oceanic and Atmospheric Administration (NOAA), who
are responsible for the operational phase of JPSS. Twosatellites are planned for the JPSS constellation ofsatellites, which, once operational, will be known as
NOAA 20, NOAA 21 etc.
Suomi-NPPThe Suomi National Polar-orbiting Partnership satellite(Suomi NPP), previously known as the National Polarorbiting Operational Environmental Satellite System

The Delta II rocket carrying JPSS-1 stands on the launchpad.
The satellite will become NOAA 20 once in orbit.
Image: United Launch Alliance / NASA

This schematic diagram illustrates the positioning of the various sensors
on the JPSS-1 satellite
Image: NASA

Preparatory Project (NPP) and NPP-Bridge was originallyintended as a pathfinder for the NPOESS programme.
Suomi was launched in 2011 as a gapfiller between the
POES and JPSS satellites, flying new instruments, on a
new satellite bus, as a measure to ensure continuity ofclimate.
Such has been the success of the Suomi-NPP satellitethat it has become the de facto first member of the JPSS
constellation. JPSS-1/NOAA 20 will join Suomi NPP in
the same polar orbit, and will also provide scientists withobservations of atmospheric temperature and moisture,clouds, sea-surface temperature, ocean colour, sea ice
cover, volcanic ash, and fire detection.
JPSS Instrumentation
The JPSS-1 spacecraft is based upon the design ofSuomi-NPP but with an updated communications systemfor downlinking the raw, unprocessed data back to Earth.
It carries the same five state-of-the-art instrumentswww.geo-web.org.uk

5

GEO Quarterly No 56

The Group for Earth Observation

December 2017

JPSS System Architecture
Credit: NASA

which will provide sophisticated meteorological data andobservations of Earth’s atmosphere, land and oceans.
ATMS
The Advanced Technology Microwave Sounder (ATMS)
instrument is the next generation cross-track microwave
sounder providing 22 channels of atmospherictemperature and moisture for operational weather andclimate applications. ATMS collects microwave radiation
data from Earth’s atmosphere and surface throughout
both day and night—even through clouds—to provide
sounding observations needed to retrieve profiles ofatmospheric temperature and moisture for civilian
operational weather forecasting as well as continuity ofthese measurements for climate monitoring purposes.
CERES
The Clouds and the Earth’s Radiant Energy System(CERES), senses both solar-reflected and Earth-emitted
radiation from the top of the atmosphere down to Earth’s
surface.
Cloud properties are determined using simultaneous
measurements from other JPSS instruments such as the
VIIRS and will lead to a better understanding of the roleof clouds and the energy cycle in global climate change.
Measurements from CERES help scientists understand thelinks between the Earth’s incoming and outgoing energy
and the properties of the atmosphere that affect thatenergy.
The first CERES instrument has flown on NASA’s Terrasatellite since late 1999.
CrIS
The Cross-track Infrared Sounder (CrIS) instrument is
the first in a series of advanced operational sounders thatwill provide increasingly accurate, detailed atmospheric6

temperature and moisture observations for weather andclimate applications. CrIS is the successor to the High
Resolution Infrared Radiation Sounders (HIRS) flown
aboard NOAA’s POES satellites.
Daily CrIS measurements are used by NOAA’s National
Weather Service to enhance numerical weather prediction
model forecasts, aiding in both short- and long-term
weather forecasting. Over longer time scales, they will help
improve understanding of climate phenomena, such as
El Niño and La Niña—including continental transport ofgreenhouse gases.
CrIS also measures atmospheric chemistry and can detect
the concentration of greenhouse gases, including carbon
dioxide, primarily in the middle and upper atmosphere.
The information from CrIS helps significantly in improving
weather and climate prediction, including both short-term
weather ‘nowcasting’ and longer-term forecasting.
OMPS
The Ozone Mapping and Profiler Suite (OMPS) is anadvanced suite of three hyperspectral instruments, which
will extend the total-ozone and ozone-profile records that
already encompass more than 25 years. These records areused by ozone-assessment researchers and policy makers
to track the health of the ozone layer. The improved
vertical resolution of OMPS data products allows forbetter testing and monitoring of the complex chemistry
involved in ozone destruction near the troposphere. OMPS
products, when combined with cloud predictions, also help
produce better ultraviolet index forecasts.
OMPS collects total column and vertical profile ozone
data and continues the daily global data produced bycurrent ozone monitoring systems—the Solar Backscatter
Ultraviolet Radiometer (SBUV/2) and Total Ozone Mapping
Spectrometer (TOMS)—but with higher fidelity and larger

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

This Black Marble image of Europe was created from VIIRS data collected by the Suomi-NPP satellite
Image: NOAA (2016)

swaths. The Ozone Mapping and Profiler Suite (OMPS) willmeasure the concentration of ozone throughout Earth’s
atmosphere. OMPS-N, a nadir-pointing instrument, will
fly on the JPSS-1 satellite mission and will be used togenerate total column ozone measurements.
VIIRS
The Visible Infrared Imaging Radiometer Suite (VIIRS)
collects visible and infrared imagery and global
observations of land, atmosphere, cryosphere and oceans,
and also flies aboard Suomi‑NPP. VIIRS generates many
critical environmental products concerning snow andice cover, clouds, fog, aerosols, fire, smoke plumes,
dust, vegetation health, phytoplankton abundance andchlorophyll. VIIRS features daily multi-band imaging
capabilities to support the acquisition of high-resolution
atmospheric imagery, plus other instrument products,
including visible and infrared imaging of hurricanes anddetection of fires, smoke and atmospheric aerosols. The
VIIRS’ Day/Night Band sensor captured the widely popularand beautiful Earth at Night Black Marble images (above).
The maritime forecasting products of sea ice and ocean
nutrients from VIIRS help the maritime and commercial
fishing industries—further improving vessel routing
and making fishery management more efficient. The
agricultural industry benefits from fire monitoring andvegetation index—along with weather warnings—which are
critical to production yield.
VIIRS produces higher-resolution and more accurate
measurements of sea surface temperature, as well as
an operational capability for ocean-colour observations
and products. Ocean-colour is an indicator of water
quality supporting a wide range of decisions from fishing
to tourism. The VIIRS’ Day/Night Band also provides
nighttime imagery, which is essential for Alaska during thewinter months.
VIIRS provides global coverage twice a day with 750 metre
resolution across its entire scan. This is a substantial
improvement for ocean ecology and carbon researchstudies, as well as for establishing accurate estimates ofsea surface temperature which are essential for predicting
hurricanes and other types of severe weather.
VIIRS operates in 22 bands of the electromagnetic
spectrum, between 0.412 µm and 12.01 µm:• 5 ‘imagery’ bands at 375 metre/pixel resolution• 16 ‘moderate’ bands at 750 metres/pixel• 1 low-light Day/Night band at 750 metres/pixelWith a 3060 km swath at the satellite’s average altitudeof 829 km, and nearly constant resolution from nadir tolimb, VIIRS imagery will be a tremendous resource for
operational forecasters. This swath width is able to provide
complete Earth coverage every 24-hour period.
VIIRS imaging optics include a 19.1cm Aperture anda 114cm Focal length. The average orbit power for the
instrument is 200 watts. In total the instrument weighs
275kg.
In Orbit
JPSS-1 now joins Suomi NPP, the joint NOAA-NASA
weather satellite, providing a constellation of two, highlysophisticated satellites, each circling the Earth fourteentimes a day, and providing full, global observations
for weather prediction. Suomi NPP, which was initiallyplanned as a research and risk reduction mission when it
launched on October 28, 2011, became NOAA’s primary
operational satellite for global weather observations on
May 1, 2014.
References
This article merely scrapes the surface of a fascinating andcomplex system, Those interesting to delve further into theintricacies of the JPSS system are recommended to visit
the EO Portal athttps://directory.eoportal.org/web/eoportal/
satellite-missions/j/jpss
For more details of the VIIRS Black Marble imagery, visit
https://earthobservatory.nasa.gov/IOTD/view.php?id=90008

www.geo-web.org.uk

7

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Les Hamilton
After fourteen eventful years, this is destined to be your final
edition of the GEO Quarterly magazine. GEO was convened at a
meeting of former members of the Remote Imaging Group in late2003, dissatisfied with the direction that the group was taking,and the launch edition of this magazine appeared in March 2004.
Pointedly, the birth of GEO occurred at almost the same time as
the fledgling EUMETCast service started outputting its complete
12-channel SEVIRI data every 15 minutes in January 2004,heralding a major change in the amateur approach to weather
satellite imaging. Prior to this, the emphasis was firmly on
providing members with construction projects, aimed principallyat the NOAA APT satellites. These included adjusting andinterfacing with the YU3UMV framestore for the display ofsatellite images, building antennas of different designs andconstructing the RF1 and RX2 receivers from kits of components.
But during the lifetime of GEO such activities have come almost
to a standstill, particularly as the EUMETCast service expanded
to make available high resolution images from the NOAA, Metop,
Fengyun, Suomi, Terra, Aqua, GOES and Himawari satellites: it’s
now just so easy to download all this data via a DVB-S2 satellite
feed. Direct reception of satellite images has been largely
abandoned, apart from a brief flurry of interest in Meteor LRPT
reception using USB DVB-T dongles a couple of years back.
Nowadays I have been reduced to trawling internet sites,
particularly NASA Earth Observatory, to fill our pages with items
that members could easily look up for themselves. Contributions
from readers have dwindled almost to zero, and compiling
Quarterlies has become a chore I can well do without.

What is the Way Ahead for GEO?

Despite the apparent total lack of invention on the part of ourmembers in the British Isles, there are enthusiasts ‘out there’ whohave been working hard on the lost art of direct reception of highresolution weather satellite images. In this respect I commend to
you the article on page 18 by Rob Alblas and Ben Schellekens
from our Dutch counterparts, Werkgroep Kunstmanen, who havedeveloped hardware and software that can receive images
directly from the European Metop satellites and the Chinese
Fengyun-3 series.
Members of the werkgroep
have never lost thedesire to develop new
hardware and software,and the big breakthroughcame in 2015 when Ben
Schellekens successfully
decoded an image frompart of a Metop passover The Netherlands.
Development hascontinued, and the grouphas finally designed asystem that will decodeand display high-resolution
imagery from NOAA,
Meteor N2, Metop andFengyun-3 polar orbiting
satellites.

8

Werkgroep Kunstmanen publish details of all their projects ina quarterly magazine entitled ‘De Kunstmaan’, the September
cover of which is illustrated here. Francis Bell, David Taylor andmyself have been members of this group for some years, andalthough the magazine is of course printed in Dutch, all nonDutch subscribers receive a PDF English version too. If you
are interested in projects relating to direct reception of satellite
imagery, and would like to subscribe to this magazine, visit
http://www.kunstmanen.net/index.php
From the Contact menu option, select Membership for
instructions, in English, for joining.
Membership is €30 per year, which brings you four copies of themagazine. The easiest form of payment is by PayPal.
Future Articles
Although this will be the final edition of GEO Quarterly magazine,
GEO will continue as a web-based organisation via its website atwww.geo-web-org.uk
and the GEO-Subscribers YAHOO Group at the URL shown
across the foot of this page.
If, in future, any GEO member comes up with an article they wish
to share with others, I will continue to be available atgeoeditor@geo-web.org.uk
to create a PDF version which can be made available fromthe GEO Website and notified to members by email (or GEO‑
Subscribers).
The new era of direct satellite reception has started
and will assuredly be boosted by the recent launchof JPSS-1. Surely there are members who would
wish to join in this ‘new wave’ of interest!

Useful Websites

Finally, here is a list of some of the websites from which I
have culled images to fill the pages of GEO Quarterly over theyears. If you have enjoyed reading excerpts from NASA Earth
Observatory, you can continue following these interesting topics
at the links below.

NASA Earth Observatory

https://earthobservatory.nasa.gov/
https://earthobservatory.nasa.gov/NaturalHazards/

MODIS

https://modis.gsfc.nasa.gov/gallery/showall.php
https://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/realtime.cgi

Sentinel 1

http://www.esa.int/spaceinimages/Missions/Sentinel-1

Sentinel 2

http://www.esa.int/spaceinimages/Missions/Sentinel-2

Sentinel 3

http://www.esa.int/spaceinimages/Missions/Sentinel-3

https://groups.yahoo.com/neo/groups/GEO-Subscribers/conversations/messages
www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Les Hamilton
During the latter half of the 20th century, up until the late
1990s, the Antarctic Peninsula was one of the fastestwarming locations on Earth. And although temperatures
since have stabilised—indeed fallen slightly—this has
left a serious legacy for the Larsen ice shelves along its
eastern margin. Until 1995 there were three ice sheets
here, Larsen-A, Larsen-B and Larsen-C, but in Januaryof that year, Larsen-A disintegrated. This occurred wellbefore the arrival of NASA’s Terra satellite with its 250
metre imaging resolution (in December 1999), and as
far as I can detect, no images of this event exist. But
seven years later, when Larsen-B suffered its sudden andrapid disintegration, it was well documented by satellite
observations as illustrated below. And on July 12, 2017,
when a huge iceberg (A68) measuring almost six thousandsquare kilometres in area and weighing over one trillion
tonnes broke free from Larsen-C, this surely signalled thestart of its demise.
The Disintegration of Larsen-B (2002)
During the Southern Hemisphere summer of 2002,
between the end of January and early March, the MODIS
instrument aboard NASA’s Terra satellite documented thespectacular disintegration of part of the Larsen-B ice shelf.
Figure 2 on page 8 was acquired on January 31, just prior
to the commencement of the breakup.
By February 17, the leading edge of the C-shaped shelf
had already retreated about 10 kilometres as the ice
began to splinter (figure 3), and the next clear view of thearea showed that a number of long narrow icebergs had
fractured from the south of the shelf (figure 4).
By March 5, imagery analysed at the University ofColorado’s National Snow and Ice Data Center (NSIDC)
revealed that disintegration of the northern section of theLarsen-B ice shelf was well advanced with the ice now
broken into a blue-tinged mélange consisting of slush andicebergs drifting into the Weddell Sea (figure 5). A total ofsome 3,250 square kilometres of shelf area had broken
apart during a 35-day period beginning on January 31,
bringing the total ice loss over a five year period to
5,700 square kilometres and reducing the area of Larsen-B
to a mere 40% of its original extent.
Many of these bergs were too tall and narrow to float
upright and had toppled over and spread out across thebay like a neat row of books that had been knocked off ashelf. When the bergs tipped over, the pure ice from theunderside of the ice shelf became exposed, and the pale
blue colour was primarily due to the reflection of sunlightfrom this ice (because pure, thick ice absorbs a small
amount of red light).
The final two images were captured as the austral autumn
arrived and show the bright blue colour of the ice debris
field fading as the remnants of the shelf became coveredby the first snows of the season. Seasonal sea ice began toform, locking most of the ice debris in place for the winter,although the April 13 image (figure 7) shows that a few ofthe largest icebergs from the southern portion of the shelf
had already drifted out of the area.

Figure 1 - The Antarctic Peninsula, showing the Larsen Ice Shelves
Map courtesy Wikimedia Commons / A. J. Cook and D. G. Vaughan

The 220 metre thick Larsen-B shelf was fed by glaciers
streaming from the interior of the peninsula. Based on
ice-flow studies, and the sediment thickness beneath it,
scientists believe that it had been stable for at least ten
thousand years, and possibly even since the end of thelast major glaciation 12,000 years ago. At the time, theLarsen-B event was the largest single breakup of its kind
known in the previous 30 years, and released 720 billion
tonnes of ice into the ocean. Over the peninsula as awhole, the extent of its seven ice shelves has declined by atotal of about 13,500 square kilometres since 1974.
Inevitably, such an event fuels speculation that its origin
lies in the 0.5°C per decade climate warming trend in thisregion between the 1940s and the end of the century.
Icebergs that break from ice shelves and float off to melt inwarmer ocean waters do not raise global sea levels because
the ice shelves themselves are already floating, even before
the ice breaks away. However, should Antarctica’s great ice
sheets, which rest on land, lose their mass to the ocean,sea levels would rise. There’s enough frozen water in theWest Antarctic Ice Sheet alone to lift global sea levels by

www.geo-web.org.uk

9

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Figure 2 - Larsen-B on January 31, 2002

Figure 5 - Larsen-B on March 5, 2002

Figure 3 - Larsen-B on February 17, 2002

Figure 6 - Larsen-B on March 17, 2002

Figure 4 - Larsen-B on February 23, 2002

Figure 7 - Larsen-B on April 13, 2002

Images courtesy Ted Scambos, National Snow and Ice Data Center, University of Colorado, Boulder, based on data from MODIS

10

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

six metres. Such melting would also alter the salinity ofthe seawater and threaten many species of marine life.
The collapse of Larsen‑B appears to have been due toa series of warm summers on the Antarctic Peninsula,which culminated with an exceptionally warm summer
in 2002. As the region warms during late summer, melt
ponds collect on the ice surface. This meltwater acts toenhance fracturing of the ice by filling small cracks, theweight of the meltwater then deepening crevasses andeventually causing the shelf to splinter. Satellite images
have provided substantial observational proof that thisis in fact the main process responsible for the peninsula
shelf disintegration.
Other factors might also have contributed to the unusually
rapid and near-total disintegration of the shelf. Warmocean temperatures in the Weddell Sea that occurred
during the same period might have caused thinning andmelting on the underside of the ice shelf. As the surface
melt ponds began to fracture the shelf, strong winds orwaves might have flexed the shelf, helping to trigger a
runaway break up.
The ice debris field did not become a permanent fixture in
Larsen Bay, and as seasonal sea ice melted the following
summer, the mélange began to drift away with thecurrents.
The Disintegration of Larsen-C (2017)
The first hint of activity in the Larsen‑C ice shelf came in 2014
with the development of a narrow rift developing on its surface.
By August 2016, at the end of the Antarctic winter, it was clearthat the rift along Larsen‑C had grown considerably longer during
the austral winter. Figure 8, acquired by the Multi-angle Imaging
SpectroRadiometer (MISR) instrument aboard NASA’s Terrasatellite shows the rift clearly.

Figure 9 - The Larsen C crack viewed from NASA’s DC-8 research
aircraft on November 10, 2016
Photo: John Sonntag / NASAwinter returned to the southern hemisphere, observations
continued, courtesy of the Thermal Infrared Sensor (TIRS)
on NASA’s Landsat‑8 and radar imagery from Europe’s
Copernicus Sentinel-1 mission.
On June 17, 2017, Landsat 8 captured figure 10, whichshows the relative warmth or coolness of the landscape.
Orange depicts where the surface is the warmest, mostnotably the areas of open ocean and of water topped bythin sea ice. Light blues and whites are the coldest areas,
spanning most of the ice shelf and also some areas of sea
ice. The blue hue of the crack itself indicates that relatively
warm ocean water is not far below the ice surface.

Figure 8 - This MISR image acquired on August 22, 2016, was the first toshow the accelerated growth of the rift in the Larsen‑C ice sheet.
Image: NASA / GSFC / JPL, MISR Team

By November, the arrival of longer days and favourable
weather prompted members of NASA’s IceBridge team tofly aboard their DC-8 research aircraft to take a closer
look at the crack (figure 9). They saw that the rift in
Larsen‑C now measured some 100 metres in width by halfa kilometre in depth—completely through to the bottom of
the ice shelf, though not yet straddling its entire width.
Scientists continued to observe growth of the crack during
the sunlit months of late 2016 and early 2017, scientists
watched closely as the crack stretched ever farther acrossthe Larsen‑C ice shelf, threatening to eventually create
one of the largest icebergs ever recorded. Even after

Figure 10 - Landsat‑8’s TIRS imaged the crack on June 17, 2017.
NASA image by Joshua Stevens, using Landsat data from the USGSThe crack had been lengthening rapidly during 2017,and by the end of June only a few kilometres remained
between the end of the fissure and the ocean. Scientists
from Project MIDAS, an Antarctic research consortium
led by Swansea University in the UK, used radar images

www.geo-web.org.uk

11

GEO Reader Peter Kinghorn acquired this virtually cloud-free MODIS image of the Antarctic Peninsula—from NASA’s Terrasatellite—on February 6, 2017. The Larsen‑C ice shelf is prominent to the east of the peninsula, in the centre of the image.
Image: LANCE Rapid Response / NASA / GSFC

12

www.geo-web.org.uk

December 2017

The Group for Earth Observationfrom the Copernicus Sentinel-1 mission started to keep aclose eye on the rapidly changing situation. The synthetic
aperture radar (SAR) on Sentinel-1A imaged the crack
on June 28 following a period during which it had been
widening rapidly as ice near its leading edge was being
weakened by generally westerly winds tending to push it
eastward, and again on July 12 when it observed the final
separation of iceberg A‑68, a huge lump of ice more than
twice the size of Luxembourg, from the Antarctic Peninsula(figure 12).

GEO Quarterly No 56

at the Larsen‑A and ‑B shelves indicated that when alarge portion of an ice shelf is lost, the flow of the glaciersbehind can accelerate, contributing to sea-level rise.
In September 2017, as the return of daylight to the
Antarctic began to illuminate the region, the Moderate
Resolution Imaging Spectroradiometer(MODIS) on NASA’s
Terra satellite was able to acquire the first true-colour
day time image showing the massive iceberg separated
from the Larsen‑C ice shelf. Figure 13 was captured on
September 11. Throughout the previous week, offshore
winds were pushing sea ice away from the shelf and out
to sea. The residual thin layer of frazil ice (gray mottled
streaks on the dark ocean) did not offer much resistance,
allowing iceberg A-68A to move out over the ocean.

Figure 11 - Sentinel 1A imaged the widening crack on June 28, 2017.
Image: modified Copernicus Sentinel data (2017) / European Space Agency

Figure 12 - Sentinel’‑A captured the first image showing that a giant
iceberg had calved from the Larsen C ice shelf on July 12, 2017.

With an area of around 6000 square kilometres andweighing an estimated trillion tonnes A‑68 is a truly
enormous iceberg—about 10% of the original Larsen‑C ice
shelf. It contains approximately the same volume of wateras Lake Ontario in North America.
The loss of such a large chunk from Larsen‑C issignificant, because ice shelves along the peninsula play
an important role in buttressing glaciers that feed ice
seaward, effectively slowing their flow. Earlier such events

Figure 13 - NASA’s Terra satellite captured this MODIS image of thecalved A‑68A iceberg on September 11, 2017
Image: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC

www.geo-web.org.uk

13

GEO Quarterly No 56

Larsen C
ice shelf

The Group for Earth Observation

December 2017

Thin clouds
over sea ice ———

A-68B

Open
water

Mélange ——A-68A

Figure 7 - Iceberg A-68 imaged in visible light (left) and in thermal infrared (right) in mid September, 2017.

NASA Earth Observatory images by Joshua Stevens using Landsat data from the U.S. Geological Survey. Story by Kathryn Hansen.

A-68 Adrift
On September 11, 2017, the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASA’s Terra satellite
captured the visible light image of iceberg A-68 (left-hand
image above) while the Operational Land Imager (OLI) andthe Thermal Infrared Sensor (TIRS) on Landsat 8 acquired
the detailed IR image reproduced above right.
The MODIS image at left shows the iceberg in natural
colour. The rifts on the main berg and ice shelf stand out,
while clouds on the east side cast a shadow over the berg.
The thermal image on the right shows the same area infalse-colour. Note that the clouds over the ice shelf do notshow up as well in the thermal image because they are atabout the same temperature as the shelf itself. Thermal
imagery has the advantage of showing where the colder
ice ends and warmer water of the Weddell Sea begins. It
also indicates differences in the thickness of ice types: forexample, the mélange is thicker (has a colder signal) than
the frazil ice, but thinner (warmer signal) than the shelfand icebergs.

14

Both images show a thin layer of frazil ice, which offers
little resistance, as winds, tides and currents try to movethe massive iceberg away from the Larsen-C ice shelf. In
the course of several weeks of observations, scientists
observed the passage between the main iceberg and thefront of the shelf widen. This slow widening came after an
initial back-and-forth movement in July broke the main
berg into two large pieces, which the U.S. National Ice
Center named A-68A and A-68B.
The collisions also produced a handful of smaller bergs
too small to be named, one of which has been drifting
northward in the passage since the break. Notice how theedges of this piece appear much sharper than the edgesof the shelf or A-68A, whose margins have already beenrounded by blowing snow and gravity: the smaller piecehas been battered and reshaped by recent collisions,
resulting in its highly defined edges.

www.geo-web.org.uk

The ruggedness of Scotland’s Northwest Highlands is revealed in this weather window, captured by the
MODIS instrument aboard NASA’s Terra Earth Observatory on November 2, 2017
Image: LANCE Rapid Response/NASA/GSFC

www.geo-web.org.uk

15

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Les Hamilton
Chile’s Atacama Desert is probably the driest place on Earth,large parts of it having gone without moisture for as long as
people have been keeping track. Yet some precipitation does fallin the region, and that water helps to shape the landscape.
Within this arid environment lies a salt flat, or playa named Salarde Atacama. Surrounded by mountains—the Andes to the eastand the Cordillera de Domeyko to the west—this is the largest
salt flat in Chile, and has no drainage outlets. The salar, whichlies at an altitude of 2300 metres, has an area of some 3000 km2
and measured approximately 100 km from north to south and
80 km in width. The Landsat 7 satellite acquired the false-colour
image at right on March 21, 2002. Red indicates vegetation,
the most abundant of which occurs around springs that dot thenorthern edge of the saltpan. Nearby soils that support somevegetation appear tan and brown.

Salar de Atacama false colour image, acquired by Landsat 7 in 2002

NASA Earth Observatory image created by Jesse Allen, using Landsat data
provided by the United States Geological Survey

sedimentary rocks (deposited by wind and water) and igneousrocks (formed from cooling lava or magma) that support novegetation.
A view across Salar de Atacama, with Licancabur volcano beyond
Image: Francesco Mocellin / Wikimedia Commons

Although it sits at a much higher elevation, the Salar de Atacama
resembles California’s Death Valley as a flat area lying between
mountain ranges. Most of what little precipitation falls usuallydrains off the mountains and flows into nearby valleys, creating
alluvial fans. The salt flat is a geologically young, dynamic
system. Occasional floods do reach the saltpan, when flood
waters transport gravel, sand, clay, and salt. Heavier materials
such as gravel and sand tend to drop out of the water sooner,
coming to rest outside the saltpan whereas clays and salts canhitch a ride all the way to the playa.

Not surprisingly, Salar de Atacama is extensively mined for salts,
and turquoise and white rectangular evaporation ponds can beseen in the centre of the saltpan, particularly in the Sentinel 2A
image opposite. Particularly important is lithium extraction, as
Salar de Atacama is the world’s largest and purest active sourceof the metal and contains 27% of the world’s known reserves.
High lithium concentration in its brine (2,700 parts per million), ahigh rate of evaporation (3,500 mm per year), and extremely low
annual rainfall (<30 mm average per year) make finished lithium
carbonate easier and cheaper to produce here than anywhere
else. Also extracted here is boron,as boric acid (up to 0.85 g/l inthe brines).

Floods initially stir the sediments inside Salar de Atacama, butmaterial eventually settles into layers of clay and salty water.
Because the playa lacks drainage, water is lost solely throughevaporation. As it evaporates, salts remain behind and form
crusts. Inside the saltpan, mottled light blue indicates surface salt
crusts.
The white colour around the perimeter of the saltpan indicatesa zone of clay and carbonate-rich material that alternately forms
a crust on the surface and redissolves with rising and falling
groundwater. Northeast of the playa, white indicates snow andice on the volcanic Andean peaks. Volcanic rocks and soils range
in colour from burnt orange to tan.
Around the playa, the false-colour green indicates rocks
that would appear red to human eyes. Blue indicates older

16
16

www.geo-web.org.uk

Salar de Atacama

Image: Roman Bonnefoy / Wikimedia Commons

This image of Salar de Atacama, the largest salt flat in Chile, was acquired by ESA’s Sentinel 2A satellite on November 15, 2017
Image: Modified Copernicus data © ESA / Sentinel (2017)www.geo-web.org.uk

17

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Rob Alblas and Ben Schellekens
With the arrival of EUMETCast, a huge amount of satellite data
is now available for amateurs. This has made the purchase of
specific equipment for each type of satellite unnecessary. Even
imagery from polar satellites can be received via EUMETCast,thus eliminating the need of a complex and, for many people,
unreachable rotor system. The problems facing amateurs are
therefore shifted from electronics and mechanics to computerand networks. For many people interested in ‘just’ the pictures,
this is a blessing; for others it’s an impoverishment of the hobby.
Reception in the old‑fashioned way is still possible, but the final
NOAA satellite was launched a long time ago now (2009). If
the NOAAs are decommissioned, not only APT but also HRPT
disappears and Timestep equipment, especially the decoder unit,
becomes worthless.
In the meantime, new satellites have been launched that send
their data to the user in the same way, that is, ‘live’ via the1700 MHz band. The Russian Meteor system still resembles
HRPT: the same receiver can be used, but the decoder must
be different. For other satellites like Metop and the Chinese
Fengyun, the case is radically different. The very simple HRPT
format has been replaced by more advanced formats: these
permit a much higher data rate, are provided with FEC (Forward
Error Correction), and are transmitted using QPSK. This requires
a different receiver and a much more complex decoder, items
that are not readily available to the amateur, and which are highly
expensive. There remains then just one option: to design andbuild them yourself.
Table 1 provides an overview of the polar satellites that can bereceived. I’ve added Fengyun-1 for completeness, but this series
has long ceased to be active. In fact, on January 11, 2007, China
conducted an anti-satellite missile test, destroying FY-1C using a‘kinetic-kill’ vehicle travelling in the opposite direction [6].
The active Meteor-N2 also transmits at 137 MHz via LRPT, which
can be received with a simple SDR dongle. However, only threeof the six channels are available in this mode. In the 1700 MHz
band, all six channels are always available, with higher quality
imagery (and without the annoying bar every so many lines).
Meteor is referred to as Advanced HRPT, but it seems to me to
be too much honour compared to Metop/Fengyun-3, as will beshown later.
At least one more Metop and some type-3 Fengyuns will belaunched in the future.
In order to be able to continue receiving polar satellites—inaddition to a rotor system and dish—you will require the flowing:• a QPSK receiver• a decoder for HRPT / Meteor / Metop / Fengyun• software for converting the received data to files and tocreate pictures
Nowadays, such systems can be realised with Software Deﬁned
Radio, but at the higher bit rates it can be difficult because it
produces very large files with raw data that must be demodulated
and decoded. A picture can only be made after the data has been
received. Watching ‘live’ with a current normal PC is not possible.
The ‘old-fashioned’ hardware method then gives opportunities.

18

Satellite

Modulation

Data Rate

FormatChannels

NOAA

PSK, split-phase

Fengyun-1

PSK, split-phase

Meteor N1
Meteor N2

Number665.4 kb/s

HRPT

AVHRR, 5x3

1.3 Mb/s

CHRPT

10

0

PSK, split-phase665.4 kb/s

AHRPT

6

0

PSK, split-phase665.4 kb/s

AHRPT

6

1

Metop

QPSK

4.66 Mb/s

AHRPT

AVHRR, 5x + more

2

Fengyun-3

QPSK

5.2-5.6 Mb/s

AHRPT

VIRR, 10x + more

3

Table 1A group like Werkgroep Kunstmanen appears to be valuable
because people with different disciplines work together. In
particular, receiver, decoder and software had to a large extent tobe developed from scratch.
The Receiver
In order to receive Metop and Fengyun, a QPSK receiver isrequired. QPSK means that data bits are transmitted in four
different phases, unlike PSK, where two phases are used to passa logic ‘0’ or ‘1’. Thus, with QPSK, 2 bits can be transmitted at thesame time: this saves bandwidth.
Demodulating QPSK is a separate subject. No carrier is sent,so this must be regenerated. Demodulation is done with a socalled Costas loop. This is a much more complex circuit thana simple phase demodulator as required for HRPT/Meteor. I
cannot describe this circuit in detail here, but a comprehensive
description, including the mathematics, can be found in ourmagazine ‘De Kunstmaan’ [1] and of course on the Internet.
The art is now to realise the demodulator in a simple and elegant
way, which is easy to build with components that are (andremain) readily available. In particular, component availability has
given us some headaches. But I think we have succeeded well,designing a receiver able to receive QPSK in addition to the old
PSK from NOAAs and Meteor. The block diagram in Figure 1
gives an impression of what is needed. The part with the LT5546,
the actual QPSK demodulator, and everything to its right, forms
the Costas loop. The receiver delivers a 2-bit data stream (onebit of which is inactive in the case of PSK reception).
The Decoder
The decoder must convert the received bitstream into a format
that will allow easy processing by the software. Transfer to
PC is via USB. The hardware has already been described in
GEOQ 30 [2]. It is based on an FPGA, Field Programmable Gate
Array. This chip enables any digital circuit to be realised. The
functional description is made in a special language, VHDL. At
first glance, this language looks like ‘normal’ software languages
such as C and Pascal, but it also has the ability to describe parallel
processes in a way that connects to digital circuits.
Using a special program (a so-called synthesiser) the description
is translated into digital components available in the FPGA.
This information is translated into a bit series and then loaded
into the FPGA. As a result, the desired functionality is now
available in the FPGA. The circuit can now be easily adaptedby reprogramming, avoiding the need of a soldering iron.
This makes it possible to extend the existing HRPT, CHRPT
and Meteor decoders, as described above [2], with Metop andFengyun. (Note that an FPGA is not like a microcontroller. The

www.geo-web.org.uk

This Metop image, from a pass on October 5, 2017, was captured by Harrie van Deursen using
the receiver described in this article, followed by processing using Rob Alblas’ wsat software.

www.geo-web.org.uk

19

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Figure 1 - A block diagram of the receiverloaded bit sequence ensures that digital components in the
FPGA are connected in the desired way and then becomesinactive.)
As mentioned in the table, there are some different data formats
in circulation. The HRPT format of the old NOAAs is very simple.
The data is almost exclusively from the AVHRR instrument,with the structure shown at the top of figure 2. The bits arepackaged in a frame to which a synchronisation word is added.
Of the 110900 bits 60 are used for the sync word, 102400 for
the AVHRR data and the rest (8440 bits) for calibration andhousekeeping purposes. A simple calculation shows that,at a bit rate of 665.4 kb/s, the transfer of this frame takes
110900/665.4 =1/6 second, meaning 6 lines per second.

of the line are. On the receiving side, these pieces must be
stuck together again. This is a much more complex task for thesoftware, but this method gives much greater flexibility. This
explains the ‘A’ in AHRPT (Advanced HRPT).
Both the more complex build-up and the larger bit rate increase
the bit error problem. To begin with, the higher bit rate (4.6 Mb/sversus 0.6654 Mb/s) gives a higher noise level in the receiver.
This has been partially overcome by using QPSK, with 2 bits
transmitted at the same time: the required bandwidth is hereby
halved. However, QPSK per se is more sensitive to noise as
the ‘distance’ between the 4 phases is smaller compared to the2 phases of PSK, given the same total transmit power.
In addition, the frame contains control bytes that are crucial forcorrect decoding. Whereas a bit error in HRPT results in a wrong
value pixel, such an error in a control byte could result in a whole
block of data being lost because it is not recognised as belonging
to, for example, AVHRR.
For this reason, FEC (Forward Error Correction) is applied.
Simply said, additional bits/bytes are added to the stream, andthese allow the reception system to detect and even correct
errored bytes to some extent. This results in much better data
quality, despite adding additional bits, which means more
bandwidth needed, so more noise.

Figure 2 - Comparison of the Frames of HRPT and AHRPTUpon reception, it is a matter of counting which bits belong towhich channel and which pixel. No error correction is possible,
which is also not necessary in this simple, low bit rate format.
The decoder only needs to recognise the synchronisation word
and then sends the rest of the bits to the PC as 10-bit units (oneunit being 2 bytes).
With Metop it’s a very different story. Although this satellite
contains the same AVHRR instrument as the NOAAs, it’s image
data amounts to only a fraction of the total being transmitted.
Metop includes the following data:• AVHRR: about 622 kb/s
• IASI: CO2 detection, 1500 kb/s
• GOME: Global Ozone Monitoring, 400 kb/s
• And more.
While, in the case of NOAA, the frame is adapted to the data
to be sent, this is not possible with Metop with its different,
large data streams. Instead, a short frame of 8192 bits is used(figure 2, bottom). The data for each line to be transmitted isdivided into pieces, along with additional bytes that indicate
which data type is present and where the start and end points

20

There is a lot of mathematics behind FEC, which I will not go
into. But with a very global description, some insight can begained. Both Metop and Fengyun use Viterbi encoding andReed-Solomon error correction.
Viterbi Encoding
Simply speaking, Viterbi encoding means that the bits to betransmitted are smeared out in time in two different ways, thus
doubling the number of bits needed to transmit them. On thereceiving side, the original bitstream can be recovered, withapproximately 2.5 dB profit. This, despite the fact that doubling
the number of transmitted bits means an increase of bandwidth
and thus noise. This coding was also used in the Voyager
spacecraft, and contributes to the fact that signals from thesedeep space spaceships are still being received (and useful).
Metop/Fengyun uses a modified version with 1/3 of the encoded
bits not being transmitted. The advantage will be somewhat
lower, but more bits (net) can be transmitted in the same
bandwidth. This process is termed Punctured Viterbi. As a result
the bitstream to be transmitted is a factor of 4/3 higher than theoriginal bitstream, instead of 2 times.
Because this encoding in the transmitter takes place at bit
level, as the last operation before the transmitter, the Viterbi

www.geo-web.org.uk

Harrie van Deursen acquired this Feng Yun 3C image, using the receiver described inthis article, on May 25, 2017 and processed it using Rob Alblas’ wsat software.

www.geo-web.org.uk

21

GEO Quarterly No 56

The Group for Earth Observation

decoding must first be done on the receiving side. After that,the synchronisation word can be searched, and the bits canbe neatly merged into the correct bytes (figure 3). This figure
also illustrates another function not present with HRPT: the‘derandomiser’. On the transmit side (in the satellite) all bits
except the 32 synchronisation bits are edited with a fixed pattern.
This is done to prevent too many zeros or ones being sentconsecutively. On the receiving side, the original bit sequencecan be retrieved by performing the same operation again using
the same fixed pattern. Only a very small amount of the logic
processing in the decoder is needed for this.
All operations referred to in figure 3 are performed by the
hardware decoder. The vast majority of the available logic in the
FPGA is required for the Viterbi decoder; the remainder of theprocessing does not require so much.

December 2017

Figure 5 - Metop data transmission.

In the case of Fengyun, however, a more difficult route is taken,
as shown in figure 6. This time, the I and Q parts are treatedcompletely separately; the I gets the even bits, the Q the odd
bits.

Figure 6 - Fengyun data transmission (receiving part)

Figure 3 - Decoder Construction for Metop

Reed-Solomon Correction
What follows is the Reed-Solomon correction. In short, a numberof bytes are added to each block of fixed length. These bytes
can detect errors throughout the block and even correct them tosome extent. Figure 4 shows the structure.

On the receiving side, therefore, two consecutive bits of I must
be presented in parallel to the Viterbi decoder (s2p: series toparallel). On the Q side, the same happens, with a second Viterbi
decoder. Following decoding this results in two bits that need to
be set ‘sequentially’ (p2s: parallel to series), so it is necessary to
fiddle with the bits, and two Viterbi decoders are required. I am
not sure what the benefit of the Fengyun method is and would beinterested to hear from anyone who does. I can be contacted at
r@alblas.demon.nl
Ultimately, it has also been possible to ‘push’ this decoder into
the same hardware, so that as a result, all current polar weather
satellites can be decoded by the same unit.
MeteorFigure 4 - Construction frame with Reed-Solomon correction block

The synchronisation word is not included in the correction
process because it has already completed its work (without
synchronisation, further decoding, including correction, would
not be possible anyway). The rest of the frame consists of a data
block and a block of correction bytes.
Reed-Solomon correction is easy to realise in software and istherefore not built into the hardware. Also, it could not be built
into the used FPGA. (Reed-Solomon correction is also used withcompact disc and DVB-S.)
Metop versus Fengyun.
The design of the Fengyun data stream initially appears identicalwith that of Metop. Both use the same Viterbi encoding andthe same Reed‑Solomon correction. However, some parts are
implemented quite differently.
QPSK and Viterbi fit very well together, and figure 5 shows thelayout for Metop. The single bitstream is converted into pairs
using Viterbi encoding, as explained; these 2 streams are thentransmitted via I and Q. At the receiving side, decoding recreates
the original single bitstream.

22

A final word about the Russian Meteor satellite(s). Although theformat they use is also referred to as AHRPT, it is actually aslimmed down version of Metop/Fengyun method. There is no
FEC, only a single main stream of data, and broadcasting is doneusing PSK/split-phase, as with HRPT. The only true similarity is
the use of a short frame, along with a (simplified) mechanism forsending the data in each line, in pieces, across various frames.
Construction, Adjustment and Required Software
The QPSK receiver consists of two circuit boards connected toeach other with a flat cable. The antenna signal enters the tuner
board (left) which has an IF of 36 MHz. The demodulator board(shown between the tuner and the display) extracts the I and Q
signals that go directly to the decoder (right).
With the design of two PCBs for the receiver, the structure andtesting is relatively simple. Moreover, this gives more flexibility.
For example, another front end can be chosen.
To make the construction as simple as possible, an off-the-shelf
TV tuner (UV1316) is used. The tuner is controlled (tuned) by an
Arduino via I²C. The receiver is tuned to the correct satellite witha rotary switch. A second switch is used to select between PSK(for NOAAs and Meteor) and QPSK. An LCD display shows thesatellite name and signal strength.
The tuner is capable of receiving up to 845 MHz, so a downconverter is always needed to receive 1700 MHz signals. This
downconverter is also the subject of one of our activities.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Figure 7 - The Receiver and Decoder

The QPSK receiver can be built in two evenings: experience withsoldering SMD components is a requirement. Some parts are
difficult to obtain.
For members of our working group, a complete package of items
can be ordered, including PCBs and mounted LT5546 on an
adapter board. The latter is a very difficult part to solder and is
illustrated in figure 8.
Adjustment of the receiver is not difficult, but requires anoscilloscope that can work in XY mode: a signal generator is not
required. Adjustment can be done on the NOAA or Meteor PSK
signal, and then on the QPSK signal from Metop or Fengyun.
A working antenna controller and downconverter is therefore
required.
For the decoder a ‘GODIL’ module was used: this contains all theparts that are difficult to solder. Together with a module for theUSB connection and some additional components, this part isvery easy to build, possibly even on an experimental board.
My website [3] provides full details concerning all
aspects of this project—in English—and also the bitfiles needed to program the FPGA.
For software, the program ‘wsat’ (not wXsat) is needed. This
catches the data from USB, does the Reed‑Solomon correction,shows one of the received channels ‘live’ and stores the dataon hard drive. Some manipulations are possible, like combining
channels into a false colour picture, and making format
conversions for HRPT Reader [4]. The software is available forboth Linux and Windows.
Epilogue
This project, which has been created by several members of
the Kunstmanen group, has not only given us a possibility forreceiving new weather satellites directly, but taught us a great
deal about these satellites.
One question that we are sometimes asked is whether wecan provide a ready-built receiver and decoder. Unfortunately,

Figure 8 - The. Adapter PCB with the LT5546 I/Q Demodulator

there are quite a few problems with this. Up until now, only a
few of these devices have been built, and this is insufficient toensure that a built and shipped device will operate without (re)adjustment, and continue to work correctly. For a self-builder
this is not a problem, but for an inexperienced user who is notin contact with whoever built the unit, this is a problem, as our
manpower is limited.
This article is written to show you that, even for amateurs,receiving and processing more advanced satellites is feasible.
Any contributions from others working in this field are morethan welcome. Like GEO, there are just a few people who write
articles for our magazines. Our magazine is now also available in
English, as PDF, so if you want to join our working group... [5]References
1 Reception of QPSK‘De Kunstmaan’ - March & June 2013
PDFs on www.kunstmanen.net (menu ‘The Kunstmaan’, ‘Archive’)
On request you can get a translation in English.
2 A new HRPT decoder
GEO Quarterly 30 (2011), page 13
http://www.geo-web.org.uk/quarterly/geoq30.pdf
3 New Generation Decoder
http://www.alblas.demon.nl/wsat/hardware/hardware2.html
4 Programs for receiving (C)HRPT, HRI and MSG pictures
http://www.alblas.demon.nl/wsat/software/index.html
5 De Kunstmaan
http://www.kunstmanen.nl
6 China’s ASAT Attack destroys Feng Yun 1C
GEO Quarterly 15 (2007), page 33
http://www.geo-web.org.uk/quarterly/geoq15.pdf

www.geo-web.org.uk

23

GEO Quarterly No 56

The Group for Earth Observation

December 2017

NASA Earth Observatory
On September 28, 2017, the Moderate Resolution Imaging
Spectroradiometer (MODIS) aboard NASA’s Aqua satelliteacquired this true-colour image of fire and smoke in the
Falkland Islands.
The Falkland Islands, a territory of the United Kingdom,
sit in the South Atlantic Ocean about 600 kilometres eastof Argentina and 1,350 kilometres north of the Antarctic
Circle. Comprised of 778 islands in total, the two largest
islands are West Falkland and East Falkland. Theseislands’ rocky, hilly, and mountainous terrain gives way
to boggy, undulating plains. Because of the near-constantwind and cool climate, few trees grow on the islands.

Instead, grassland and heath dominate the vegetative
landscape. About 92% of the land is used for agriculture,most of which is based in raising sheep and cattle. Indeed,
the sheep and cattle far outnumber the permanent humanpopulation on the island.
In the early springtime, farmers often deliberately burnpastureland to encourage growth of fresh vegetation. Whenlambs are born, the ewes and young are moved to fresh
grassland to graze. Smoke from fires in this image, which
is clearly visible blowing across East Falkland Island,
most probably arises from prescribed or agricultural fires
designed to improve pastureland.

Image: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC

24

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

John Tellick
Sunglint is a phenomenon that is observed whensunlight reflects from the surface of the ocean at thesame angle as it reflects back to the satellite sensor
viewing the surface. In the affected area of the image,smooth ocean water becomes a silvery mirror, whilerougher surface waters appear dark. I’m sure allreaders will have seen sunglint on polar satelliteThis Metop-B image from June 30, 2017 shows strong
sunglint between Greece and Libya.
Image © EUMETSAT 2017

images quite regularly, and there have been somefairly spectacular examples in the Mediterranean thisyear.
I find that the phenomenon is enhanced if you use an
RGB125 channel combination: i.e. channel 1 for red,channel 2 for green and channel 5 for blue.

This Metop-A image from July 7, 2017 shows strong
sunglint between Sicily and Tunisia.

www.geo-web.org.uk

Image © EUMETSAT 201725

GEO Quarterly No 56

The Group for Earth Observation

December 2017

This example of sunglint on the eastern Mediterranean sea was observed by Metop-A image on July 10, 2017
Image © EUMETSAT 201726www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

In this composite image where 24 hours worth of NOAA 19 GAC passes for August 17, 2017 have been combined, sunglint can be observed on
every pass that includes ocean surface north of the equator

Sometimes the sunglint
region of a satellite image
reveals interesting ocean or
atmospheric features thatthe sensor does not typicallyrecord. This image of theocean between NW Australia
and Indonesia shows a large,
overlapping wave pattern
within the sunglint region of
the image.

This MODIS image from NASA’s Terra satellite, over Shark’s Bay in Western Australia, shows gravity waves
within an area of sunglint.
Image NASA

www.geo-web.org.uk

This wave pattern is not due
to large ocean waves, however
but from atmospheric gravity
waves above the surfaceof the ocean. Atmosphericgravity waves form whenbuoyancy causes air to riseand gravity pulls it backdown. On its descent to the
low-point of the wave (thetrough), the air touches
the surface of the ocean,roughening the water. The
long, vertical dark lines
show where the troughs ofgravity waves have roughened
the surface. The brighter
regions show the crests of theatmospheric waves, beneath
which the water is calm andreflects light directly backtowards the sensor. Clouds
commonly form at the crestsof the waves, and such clouds
are visible throughout thisscene.

27

Sunglint in the Caribbean as Hurricane Harvey advances on Texas in this Metop-A image acquired on August 24, 2017
Image © EUMETSAT 201728www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

NASA Earth Observatory
On September 26, 2017, the Operational Land Imager(OLI) on the Landsat 8 satellite captured a natural-colour
image of a large phytoplankton bloom in western Lake
Erie (figure 1). The bloom was first reported in mid-Julyin Maumee Bay, just east of Toledo and by late September
had extended east into the central basin and north toward
the coast of Ontario. At the time of this image, the highest
densities were detected along the coast of Ontario and in
Maumee and Sandusky bays.
According to the National Oceanic and Atmospheric
Administration, the bloom contains microcystis, a typeof freshwater cyanobacterium. These cyanobacteria can
produce toxins that can contaminate drinking water, posea risk to human and animal health when there is directcontact (skin irritant, respiratory distress), and generally
disturb coastlines.
Warm water temperatures and nutrients from farm
runoff can sustain phytoplankton blooms well beyond thesummer. While leaves and crops on land have taken on
typical autumn oranges and browns, Lake Erie continues
to display vivid shades of green. Blooms form at themouth of the Maumee River, then commonly drift into thecentral basin where the outflow of the Detroit River pushes

Figure 3 - A MODIS view of Lake Erie from Terra on September 24, 2017
NASA Earth Observatory image by Joshua Stevens
using MODIS data from LANCE/EOSDIS Rapid Responsethem away. In calm conditions, lack of mixing allows theformation of scums—areas where cyanobacteria clump
together into floating mats. These are the brightest green
areas in the image.

Figure 1 - Phytoplankton bloom over western Lake Erie
NASA Earth Observatory image by Joshua Stevens
using Landsat data from the U.S. Geological Survey

www.geo-web.org.uk

29

GEO Quarterly No 56

The Group for Earth Observation

December 2017

NASA Earth Observatory

NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response
Story by Kathryn Hansen.

If Antarctic icebergs could talk, they would have epic stories totell of calving, colliding, breaking apart, and drifting thousandsof miles across the ocean. Since they don’t talk, scientists relyon satellites to piece together the life stories of icebergs, someof which have been adrift for decades.

coast to the Mertz Glacier in East Antarctica. Along the way, it
broke apart, and one segment became B-09B (not pictured),which in turn collided with the floating tongue of Mertz Glacierin February 2010 and formed -28 iceberg. C-28 subsequently
broke apart into pieces including C-28B, pictured here.

Four icebergs of various sizes and ages are visible infigure 1, which shows a region of the Southern Ocean, near
the Weddell Sea and the Drake Passage. It was acquiredon October 20, 2017, by the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASA’s Aqua satellite. A fifth
white feature in the image may have the appearance of aniceberg, but is in fact Elephant Island—buried under snow andice—where Ernest Shackleton famously sought refuge in 1916,
following his expedition’s entrapment in the Antarctic ice.

The two other icebergs pictured (B-15T and B15Z) broke from
B-15, the largest iceberg ever measured with satellite imagery.
When that berg calved from the Ross Ice Shelf in March 2000, it
was almost as large as the state of Connecticut.

Icebergs are named based on the quadrant of Antarctica fromwhich they calve. Most of the icebergs in this image—those
whose designations start with the letter ‘B’—come from theRoss Sea area and have drifted counter-clockwise aroundthe continent. Iceberg B-09F is a fragment that broke from theB-9 iceberg, which calved from the Ross Ice Shelf of West
Antarctica in 1987. It has taken the massive iceberg morethan two decades to drift out of the Ross Sea and along the30

The icebergs in this image were carried to their present
locations by a combination of ocean currents: the coastal
countercurrent, which flows counterclockwise close to
Antarctica; and the Weddell Sea Gyre, which spins clockwise
and pushes the bergs into the western Weddell Sea to thenorth.
As they continue to drift north, these bergs will probably get
kicked back toward the east as they encounter the powerful
Antarctic Circumpolar Current funneling through the Drake
Passage. This passage keeps these bergs from continuingcounter-clockwise around the continent, forcing them to quickly
whip north toward the equator and rapidly melt.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Ed MurashieThis article first appeared in the December 2003 edition of the Remote Imaging Group Journal

One of the nicest gifts received is one that you can’t justify
buying yourself; then you receive it as a surprise. Suchwas the case earlier this year when I saw an ebay auction
for some TIROS slides. I was intrigued but, without seeing
a picture or better description, I decided not to bid on
them. After the auction closed, I checked out who wonthem but it seemed that nobody had even placed a bid.
Yet on my birthday, my best friend handed me a present
that rattled like a puzzle box. Upon unwrapping it, I
discovered a metal slide box containing an old paper
manual titled TIROS I Picture Documentation and 300 black
and white slides. Well, you can imagine how I spent thatevening! TIROS-I was launched on April 1, 1960 and was
designed to test the feasibility of a Space-based camera
to obtain weather pictures. From April 1 until June 29,
TIROS-I transmitted 22,952 images, of which 19,389 wereused for weather forecast purposes. Within an hour anda half after launch, the first image showed ice blockagein the St Lawrence Seaway (figure 2). The first major
storm, a cyclone in the South Pacific to the north of New
Zealand, was imaged on April 10 and the data was sent toAustralian meteorologists (figure 3).

Figure 1 - An early TIROS publicity poster

A rocket launch on June 1, 1960 was going to be scrubbed
because of lack of weather data over the Gulf, but was
performed at the last minute because of a TIROS weather
chart received at the station. These are just a few of theresults obtained from TIROS I. The TIROS experiment was
declared a success.
Two 500-scan-line TV cameras were mounted to thebottom base plate of the satellite as shown in figure 4.
One camera had a 104° wide-angle lens which covered anominal 600,000 square mile area, about twice the sizeof Texas, with a 2.7 kilometre/pixel resolution. The othercamera had a 12° narrow-angle lens, which covered a 5000
square mile area with a 0.5 kilometre/pixel resolution(figure 5). The satellite only took visible images of thesunlit Earth: no infrared or night-time images were taken.

Figure 2 - The very first TIROS image

Each camera used a vidicon tube, half an inch in diameterand four inches long instead of the bigger, heavier, image
orthicon tubes used in commercial TV cameras. The vidicon
tube contained a thin transparent photo-conductive
layer, positive electrode. The tube’s electron beam first
deposited a layer of electrons on this surface, then the
shutter opened for 1.5 milliseconds and the image of the
Earth was focused on this layer. Where light struck thesurface, the photo layer became conductive; where there
was no light, the layer remained non-conductive. The
deposited electrons repositioned themselves based on
the conductivity. Finally, the electron beam scanned thesurface and where there were still electrons, the beam wasdeflected; where there were no electrons, the beam passed
through and a current was measured from the electrode.
The 500-line scanning process took two seconds tocomplete. The process was repeated either 10 or 30
seconds later, after the electrons had been flushed fromthe surface and a new layer deposited. The cross andwww.geo-web.org.uk

Figure 3 - The April 10, 1960 Pacific storm

31

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Figure 4 - TIROS instrumentation, cameras in the foregroundwith the tape recorder between them

L-shaped cross-hairs were etched on to the glass surfaceof the vidicon and used to correct for electronic and data
presentation distortion. An optical filter was used to pass
only the red end of the visible spectrum, thus avoiding
blue haze. The satellite could be commanded to send
real-time pictures when it was within a 1500 mile rangeof the two Command and Data Acquisition stations (CDA),
or record them any time on an onboard magnetic taperecorder.
Each camera had it’s own independent tape recorderwhich could store up to 32 images taken at 30-second
intervals. Separate timers commanded the tape recorders‘on’. When the satellite was over one of the CDA’s, it would
playback the stored images in 100 seconds, in reverse
order, and then could transmit real-time images at either
10-second or 30-second intervals. An image including thewestern USA with the Baja California peninsula prominentis shown in figure 6. Note that the image is sideways-on.
Turn the page 90° clockwise to view it normally.

Figure 6 - A TIROS image of the USA showing Baja California(side-on), with the panel-board below.

When transmitting real-time images, the satellite could
send either camera image or alternate between the twoon the same transmission frequency. The two CDA’s
were Kaena Point in Hawaii and Fort Monmouth in New
Jersey. Fort Monmouth was chosen because it was close
to the RCA Laboratory headquarters in Princeton New
Jersey: they were the contractor for the TIROS satellite.
Each camera had it’s own 2-watt transmitter which wasconnected to the four antennas located on the underside of
the satellite. The camera or tape data frequency-modulated
an 85 kHz sub-carrier which then frequency-modulated
a 235 MHz carrier. The slow scanning rate allowed atransmission bandwidth of 30 kHz instead of a typical TV
bandwidth of 6 MHz, which in turn permitted the use of alow power transmitter. Having two independent cameras,
recorders and transmitters provided redundancy, which
was especially useful on TIROS III when one camera failed
early in its mission.
The nearly circular 390 nautical mile orbit of TIROS I
is depicted in figure 1. The 48° inclination allowed thespacecraft to image the Earth from 55°S to 55°N latitude
when the Earth was below the satellite, about one-third ofeach daylight orbit. The orbital period was 99.24 minutes.
The satellite was spin stabilised between 8 and 12 rpm,with the spinning axis parallel to the cameras.

Figure 5 - A comparison between the wide-angle (left)
and narrow-angle cameras aboard TIROS‑1

32

As the images were received, they were displayed on a
TV screen and recorded on magnetic tape. Under the

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Figure 7 - Successive TIROS-1 images show the satellite motion as it passes northbound over north Africa and France

TV screen was a lighted panel-board that displayed thestation, orbit number, frame number, camera number,sun angle and tape or direct mode (figure 6). The sun angle
and frame numbers are the summation of the digits. A
35 mm camera was then used to photograph the TV screen
and lighted panel board. My 1960 slides are copies of
those original filmstrips.
Using information from the satellite’s Earth horizon
sensors and tracking data, a library of projection grids
was created. The slides were then loaded into a projector
and the image was projected on to a table with one of thegrids (figure 8). The projector was adjusted until the scale
matched the grid and the grid was moved and rotateduntil the horizon and Earth features matched the image.
The major weather features were then sketched on to theprojection grid. Next, the weather features were transferredby hand to a rectangular transfer grid chart. Finally, theseweather features were transferred by hand to the final

latitude-longitude weather chart and weather symbols
were added.
Figure 9 shows a completed chart made from one of these
TIROS I images. Computer methods were developed togenerate the maps during the TIROS II mission. The
original weather charts were discounted for the first few
days because of perceived location inaccuracies. It wasn’t
until the third day when the Air Weather Service and Naval
Weather Service proved their location accuracy using thecoast of North Africa that they were then radio facsimiled
to all US and European meteorologists.
The images are available from the National Climatic Data
Center, Asheville, NC and an additional set is retained at
the Goddard Spaceflight Center for reference purpose.
Acknowledgments
My thanks to the following information sources, which
proved invaluable in compiling this article.

• Widger, William Jr. - ‘Meteorological Satellites’.
New York; Holt, Rinehart and Winston, 1966.
• Jakes, John - ‘TIROS Weather Eye in Space’.
New York; Julian Messner, 1966
• Weather Bureau - TIROS I Picture Documentation.
Washington D.C.; Meteorological Satellite
Laboratory, March 1961
Figures 1, 2, 3, 6 and 8 courtesy the National
Oceanic & Atmospheric Adminstration (NOAA),NOAA Central Library

Figure 8 - Preparing a Weather Chart

Figure 9 - A finished weather chart based on a storm in the north Pacific
Ocean during May 19-20, 1960

www.geo-web.org.uk

33

Enrico Gobbetti captured this image from Meteor M2’s 09:09 November 11 pass when the satellite was transmitting three visible channels, theinfrared having been temporarily deactivated, presumably for decontamination of its sensors.

34

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

NASA Earth Observatory
The Aral Sea and Lake Balkhash have a lot in common,
both lakes being located in an arid part of central Asiaand both sitting in endorheic basins (neither has anoutlet) so that both both are somewhat saline. But
whereas the Aral has become severely desiccated sincethe 1950s, Balkhash is currently enjoying a moderate(though almost certainly temporary) expansion. Spanning
16,400 square kilometres in eastern Kazakhstan, Lake
Balkhash is the largest lake in central Asia and fifteenth‑largest in the world. The natural colour image of thesouthwestern part of Lake Balkhash shown opposite(figure 3) was captured by the Operational Land Imager(OLI) on Landsat 8 on October 9, 2017.
Water in the western part of the lake is almost fresh—suitable for drinking and industrial uses—whereas theeastern side of the basin is brackish to salty. The westernside is also murkier, permitting light to penetrates toonly around one metre, compared with more than fivemetres on the eastern side. This murkiness, and thewater’s milky, yellow-green colour, is most likely due tosediments suspended in the water.

Figure 1 - Lake Balkhash, imaged by the MODIS instrument aboard Nasa’s Aqua
satellite on October 11, 2017
Image: LANCE Rapid Response/NASA/GSFC“The lake is very shallow, and it is windy nearly
every day, so waves can stir up sediments fromthe bottom,” stated Niels Thevs of the University ofGreifswald (Germany) and the Central Asia officeof the World Agroforestry Center.
Anywhere between 70 to 80 percent of tBalkhash’s water
comes from the Ili River, which enters the lake along its
eastern shoreline. The surrounding delta (green) is now
one of the largest wetlands in Central Asia.

OrtaaralIsland“I imagine that the wetlands of the Ili Delta look likethe wetlands around Aral Sea did 50 years ago,”
said Thevs.
Thevs describes large parts of the Ili Delta th)at are only
accessible by boat, where you can cruise for hours amid
3-metre tall reeds. These reeds (Pharagmites australis)
are considered invasive in the United States but not soin the Ili Delta, where the plant is an important part of theecosystem. Thevs also describes parts of the delta where
the water is so crystal clear that you can see fish andwater plants up to 8 metres below.
If you were to cruise in a boat across the main part of thelake, you could count 43 islands with a combined area of
66 square kilometres, according to Zhanna Tilekova of
Kazakh National Technical University, who has publishedresearch on the region’s geoecology. However, thosenumbers can change. Tilekova noted that, as waterlevels decline, new islands form and the area of existingislands increases. In the western part of the lake, Tasaralisland (outside this image, to its north) and Basaralisland (highlighted in figure 3 ‑ next page) are the largest.
Ortaaral and Ayakaral islands (figure 2) are also relatively
large. Vegetation, probably small brown shrubs (Saxaul),can grow on these islands. The white areas are saltpans.
Story by Kathryn Hansen.

AyakaralIslandFigure 2 - This detail from the main image opposite shows Ortaaral and Ayakaral
islands to the southwest of Lake BalkhashNASA Earth Observatory image by Joshua Stevens
using Landsat data from the U.S. Geological Survey

www.geo-web.org.uk

35

GEO Quarterly No 56

The Group for Earth Observation

December 2017

BasaralIslandFigure 3 - The southwestern portion of Lake Bakkhash as imaged by Landsat 8 on October 9, 201736
36

NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey

www.geo-web.org.uk

Harry Arends captured this image from Meteor M2’s 10:33 UT pass over The Netherlands on November 12, 2017,which shows a blast of
Arctic air engulfing the British Isles. The LRPT Meteor data were received using an RTL-SDR dongle and SDRsharp v 1601 software.

www.geo-web.org.uk

37

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Les Hamilton
Last March, in GEO Quarterly No 53, I introduced readers toLand Viewer, an on-line initiative from California based Earth
Observation Systems (EOS). This is a cloud-based tool that allows
users to search and analyse huge volumes of Sentinel-2 data
stretching back up to 180 days. Land Viewer is an on‑the‑fly, real‑time image processing and analysis service, which, claim EOS,
can provide:• instant access to petabytes of new and archive data
• the ability to find geospatial images on any scale in two
mouse clicks by selecting the required territory on the map
or by location name• on‑the‑fly imagery analytics, with the option to download
any images required for business purposes.
There seems little doubt that the version offered earlier in theyear was a beta version, as the current offering is considerably
slicker, and features some major improvements.
Navigation and Image Selection
Land Viewer is accessed from the following URL
https://lv.eosda.com/
which reveals the screen illustrated in figure 1. This screen
forms the background to all site operations, which are controlled
by buttons to either side of the display. Some of the tools areinactive until a satellite scene has been selected.
The map of the world opens, by default, over the United States,
but can be freely dragged around the screen with the left mousebutton. Zooming in and out is achieved using the mouse’s scroll
button, or by clicking the Zoom Control buttons on the screen.
Bearing in mind that each Sentinel-2 tile (image) measures only
100 kilometres square, it is wise to use the Rectangle Tool todraw a fairly small rectangle around your chosen area. This willconcentrate search results where you want them. If you click theLayers button, and select ‘Satellite’, the map will be replaced bya satellite view of the scene. An example is shown in figure 2,
where the map has been dragged to the Canary Islands andzoomed in to Tenerife.
To display the available Sentinel-2 images, click the Sentinel-2
button in the right-hand panel. The panel’s contents now change
to show thumbnail pictures of all archived Sentinel-2 data forthe previous 90 days. Notice that not every thumbnail in figure 2
includes Tenerife: some include parts of the island of La Gomera
to the southwest. This is because images that merely overlap theselected rectangle very slightly will be included in the thumbnail
selection.
If you now wish to download the full resolution ‘Red’, ‘Green’ and‘Blue’ image tiles for processing into a colour composite, click theappropriate thumbnail.
Signing In
At this point, or perhaps later when you click a download button,
you will be asked to ‘Sign in’ to Land Viewer, and the window
shown in figure 3 appears. There is no payment involved: this isjust a necessary formality to control the quantity of free imagery
amateurs can download (ten images per day; though commercial
users can pay for unlimited access at $49.99 per month). If you
already have a Facebook, Google or Linkedin account you can

38

Figure 1 - The opening Land Viewer screen (annotated)

sign in simply by clicking the appropriate button. Otherwise, justenter your email address in the appropriate field and provide a
password of your choice.
Downloads, as stated, are free for amateur use, but are restricted
to ten different scenes each day.
The criterion here is clicking on a thumbnail, not making thesubsequent download, so do think carefully and scan through all
the thumbnails that are presented before making your selection.
After selecting a thumbnail, a colour composite of the Sentinel
image is superimposed over the screen as illustrated in figure 4.
You can use the Zoom Controls to enlarge this image andexamine it in detail. Clicking the Toggle Labels button adds/
removes labels to the image to help you find your way around it.
You are now ready to download the individual ‘Red’, ‘Green’ and‘Blue’ ﬁles.
Downloading Sentinel L1 Image Files
As soon as you have selected an image by clicking on its
thumbnail, the previously inactive tools at upper right in figure 1
become available, most importantly the Download Scene button.
Clicking this button updates the right-hand panel once morewith the details shown in figure 5. Select Analytic, highlighted in
the red rectangle. This updates the panel once more, this time
providing access to all 12 channels of Sentinel-2 data. Figure 6
shows the upper part of this screen, which contains the threechannels needed for creating true-colour images. Helpfully, these
are labelled B02 - Blue, B03 - Green and B04 - Red.
When the mouse is hovered over each of these channels in
turn, a download arrow pops up to the right (as shown for theblue channel in the illustration). Click this once and repeat forthe other two channels. Immediately, new panels pop up at
the bottom right corner of the screen, stating that the file has
been ‘queued’ (figure 8). These files do not start to download

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Figure 2 - The island of Tenerife is selected against a ‘Satellite’ background

immediately: usually there is a delay of a few minutes, but within
five minutes or so, they should have downloaded on to your hard
drive. Do not keep clicking a download link believing that it has
failed to register; if you do so, you will simply end up downloading
multiple copies of the same file. As a general rule, each fileamounts to about 100 megabytes of data.
At upper left on figure 4 you can see the counter, a series of ten
small rectangular boxes, which measure the progress of yourdownloads for a particular day. In this instance, only the first of
the boxes if filled with solid blue, showing that this was the firstimage I selected. Once all boxes are filled, you have used up
your quota for the day.
Processing Sentinel‑2 RGB Files
The final RGB image of Tenerife appears in figure 10 on page 36.
To combine each set of three Sentinel‑2 files that you download
you will require a program called Sentinel2toJPEG, compiled byDavid Taylor, and which can be downloaded fromhttp://www.satsignal.eu/software/Sentinel2toJPEG.zip
www.geo-web.org.uk

Figure 3 - The sign-in screen

39

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Figure 4 - After selecting a thumbnail, the tile outline (large blue square), and Sentinel‑2 image are overlain on the map

Figure 5 - Select ‘Analytics’ here

40

Figure 6 - Download the R, G and B files here

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

David has also prepared a web page detailing how to obtain
Sentinel‑2 data, and with a number of splendid samples of thetype of imagery that can be obtained at
http://www.satsignal.eu/wxsat/Sentinel/Sentinel-2A.html
Use of this software was explained in detail on page 31 of
GEO Quarterly 53. If you missed this, you can download a PDF
copy of this quarterly from the GEO website at
http://www.geo-web.org.uk/quarterly/geoq53.pdf
Other Satellites
When you first open Land Viewer, you are presented with a list ofeight potential sources of satellite data. Only two of these provide
data that can be decoded by the Sentinel2JPEG software,
Sentinel -2, which is the subject of the foregoing, and Landsat-8,
and both of these are described in the GEO Quarterly 53 article
referred to above..
Other Features: Calendar, Sunshine and CloudAt the top of the Scene Search screen (figure 4) is the panel
illustrated in figure 7, which allows user selection over the images
displayed.

Figure 8 - Files queued for downloading

Clicking the right-hand part of this panel displays graphs showing
the cloudiness and solar elevation relevant to the area selectedacross the date range chosen. Although clicking over thesegraphs refreshes the scene list, in my experience, it had no effecton the particular images displayed.
Conclusion

Figure 7 - The Image Control Panel

Clicking the date at the left hand side opens a calendar on
which dates where Sentinel‑2 imaged your region of choice
are highlighted in yellow. Double-clicking one of these dates
brings that scene into view immediately. By default, the calendar
provides data stretching back just 90 days, but there is a
‘Custom Button’ that can extend this to 180 days (the maximum) or
even reduce it to just the previous week.

Land Viewer is a superb tool which allows the amateur to accessbrilliant high-resolution images from Sentinel‑2 and Landsat‑8,
the former at 10 metres/pixel, the latter at 30 metres/pixel. There
are features I have not covered but which readers can explore forthemselves: applying Contrast Stretching to images, exploring theBand Combination option or using the Comparison Slider to comparea Sentinel image with a GoogleMap background (‘Satellite’ fromthe Layers List).

Figure 9 - Sentinel 2A captured this image of Venice on October 16, 2017
Image: Modified Copernicus data © ESA / Sentinel (2017)www.geo-web.org.uk

41

Figure 10 - The final RGB true-colour image of Tenerife
Image: Modified Copernicus data © ESA / Sentinel (2017)42www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Cedric Roberts M.B.E.

This article first appeared in the December 2003 edition of the Remote Imaging Group Journal

How often have you been transfixed whena thunderstorm raged overhead? Of allof Nature’s elements a thunderstorm issurely one of the most aweinspiring, areminder that Man is but a small part ofa complex and wonderful world. Somefind these storms of such interest thatthey motor for miles in an attempt to
get as close to them as is possible: the‘Storm Chasers’ of the mid-United Statesin particular. Others feel so intimidated
that they retire to a dark cupboard or sit
beneath the stairs. Most, however, treat
thunderstorms as part and parcel of atypical summer in this country, an eventthat soon passes, leaving the countrysideor town with that pervading smell of moist
soil or wet tarmac.
One such storm moved into the West
Midlands on May 13, 2003 at around13.40 UT, and was to have a mostprofound effect upon my daily life over the
next few months. The day, up till that time,
had been warm and sunny with occasional
light showers, until the appearance of
towering cumulo-nimbus cloud from thewest heralded the imminent arrival of astorm. After a brief fall of small hail thefirst lightning strike occurred some miles
away and I immediately began the task ofpulling as many plugs as I could from myrather complicated computer system.
Since I run a co-operating climate station
with the Met Office and have a dual set‑up for satellite acquisition, HRPT, wefax
and the new MSG, I make use of threecomputers, all networked together. In
addition, one of these carries a modem
and it was the connection to this that I
was most anxious to remove. A frenetic
period ensued as I worked as quickly as
possible to remove plugs and leads, only
to be thwarted by Nature! A vivid flash withan instantaneous clap of thunder brought
my work to a premature end. I heard a
distinct ‘crack’ somewhere in the room but
was very relieved to find that most items
seemed to be functioning.
How mistaken I was! On careful
examination—once that the storm had
passed—I found that several items wereno longer working. I tried the Dartcom
HRPT system only to discover that thesignal from computer to dish rotator was
working, but that the return signal wasnot. Turning my attention to my automatedweather logger it was obvious that this
too, had suffered some damage, as the
LCD display was blank. I next found thatthe 21-inch monitor to the main climate

NASA’s Aqua satellite acquired this MODIS image of the British isles just one hour following thefateful lightning discharge that destroyed much of the author’s weather equipment
Image: LANCE Rapid Response/NASA/GSFC

computer had failed though the computers
did, in fact, seem to be working. As therest of the day passed and I probed
deeper into my equipment it quickly
became obvious that major damage had
been sustained.
Over the course of the following week,
more and more items were found thatwere malfunctioning. On the roof the
Vector Wind System had been blown and
the Skye radiometer was also damaged,
though the electronic sunshine sensor on
the same mast had not been affected. In
the logger the memory boards had beenblown and serious damage had been
done to the analogue to digital converter.
All of these items had to be removed
and replaced, a task that I had to ‘farmout’ to others as my health prevented mefrom performing the work myself. As oftoday, October 12, most items have been
replaced with just the analogue to digitalboard requiring attention. The work to
the computer, logger and satellite system
has so far cost over £900 though the lossof data has been far more of a problem.
I have always treated thunderstorms
with the utmost respect, having had a
www.geo-web.org.uk

grandmother who was so petrified ofthem that she turned all mirrors, removed
cutlery from the table and opened doors
and windows. However, I had neverpreviously sustained any damage from astorm during the half-century that I had
been submitting data.
Careful reflection on the events of that day
has revealed several things. Firstly, I had
not suffered a direct strike, but a surge
in the mains and wiring had been thecause of much of the trouble. Indeed, thesame flash had moved north westwards
across the sky from my area and had
struck houses at Colley Gate near Cradley
Heath. The roof of one house had been
removed and a woman who was on thetelephone at the time ended in the local
hospital. Had I taken a direct hit, I am left
wondering how much more damage would
have ensued and I was left pondering if I
had taken the possibility of damage fromlightning far too lightly. This brings me to
one final point, that of trying to discover
what, if any, kind of protection against
such damage can be made. I have turned
my attention to surge protection plugs in
the computer leads, but have no real wish
to install a lightning conductor on the roof.

43

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Ed Murashie
With the launch of the geostationary
satellite GOES-R last year and lastmonth’s launch of the polar satellite
JPSS-1, now more than ever is theUnited States a weather-ready nation.
Not only is the United States better
prepared but so is the world, since
the data from these two satellites isshared freely with over 200 countries.
What you may not know is that polarsatellites contribute 85% of the datathat goes into prediction models, andthat data sharing agreements are
made through the United Nations
instead of thousands of mutual
agreements. Individual country
agreements may not have been madein some cases because of the current
relationship among those nations.
JPSS-1 is short for Joint Polar
Satellite System and is a joint venture
between the National Oceanic andAtmospheric Administration (NOAA)
and the National Aeronautic andSpace Administration (NASA). But
its origins came from a program
called the National Polar-orbiting
Operational Environmental Satellite
System (NPOESS) which was to havebeen a joint venture between NOAA,
NASA and the Department of Defense(DOD).

The fully intergrated, JPSS-1 weather satellite ready for launch at Vandenberg Air Force BasePhoto: Ball Aerospace

The idea was to combine all of the US
weather satellite systems into one.
But in 2010 congress abandoned theidea leaving NOAA/NASA’s JPSS and
DOD’s DMSP systems separate. This
worked well, since NOAA and NASA
have been partners since the launchof the first TIROS on April 1, 1960.
In October 2011, shortly after the
NPOESS concept was abandoned, theNPOESS Preparatory Project satellite(NPP) was launched. NPP was later
renamed Suomi NPP on January 24
2012 in honor of Verner E Suomi,
a meteorologist at the University of
Wisconsin who is considered thefather of satellite meteorology.
NPP was the bridge between theprevious generation weather
satellites like NOAA-19 and the
new generation JPSS-1, which was
renamed NOAA-20 after it achieved
orbit and started enabling systems.
It was meant to be the researchsatellite version of JPSS-1 but, after

44

The scene at Vandenburg Air Force Base as the Delta II rocket awaits lift-off
Photo: Ed Murashie

www.geo-web.org.uk

December 2017

The Group for Earth Observation

proving its capability, it became the primary operation
weather satellite in May 2014. The data from NPP was
accurate enough to allow the Florida Governor to declarea statement of emergency six days prior to Hurricane Irma
making landfall. When asked if it was accurate enoughto eliminate hurricane hunter flights through the eyes ofhurricanes, and radiosondes, a National Weather Service
representative said they will always use the additional data
to improve prediction models.
It is obvious what NOAA gets out the joint relationshipand satellite data. But what is NASA’s role; and what if
anything do they get out of the data? First, NASA is thesatellite bus, payload and launch vehicle acquisition
partner with operations out of Goddard Spaceflight Centerin Greenbelt Maryland. As for the data, NASA asks the
big questions like,‘is the ozone hole getting bigger’, ‘whatis happening to the length of the growing seasons’ and’is there an imbalance in the radiation Earth budget’? It
uses data from NOAA and other satellites to answer thesequestions. For the answers to these questions read on.

GEO Quarterly No 56

and launch of MakerSat-1 from the International Space
Station. EagleSat-1 from the Embry-Riddle Aeronautical
University in Arizona will test the use of super capacitors
in the battery bank and measure of the orbit decay rateusing GPS. RadFx-Sat from the Radio Amateur Satellite
Corporation in Maryland and Vanderbilt University in
Tennessee will measure the radiation effects on CMOS
memory circuits. MiRaTA from the Massachusetts
Institute of Technology will test new radiometer and GPS
receiver technology which, if successful, could find its
application in future generation weather satellites.
JPSS-1 is the first of four satellites in this series withcurrently planned launches in 2021, 2028 and 2031.
After a successful ninety day check out phase, NOAA‑20
will become the primary operational weather satellitewith Suomi NPP as the secondary operational satellite.
NOAA‑20 is based on the same Ball Aerospace BCP‑2000
spacecraft bus as Suomi NPP. More about the spacecraft
bus and two paper models that be printed out andassembled can be found at this URL.
http://www.ball.com/aerospace/programs/jpss-1

NOAA 20
NOAA-20 carries all of
the same instruments as
Suomi NPP but was designed
from the beginning as the first
operational, next generation
satellite, with a seven year
lifespan instead of five. Les
Hamilton has done a great jobof describing the instruments
in a separate article in thisissue so here I will focus on the
Delta II rocket that gave JPSS1 a boost into space, someinteresting JPSS details and the
CubeSats that hitched a ride.
NOAA-20, 4.51 metres long
and weighing 2295 kilograms,
was launched on Delta II’s
most powerful 7920-10C
configuration, while NOAA-19,
at 1438 kg, was launched on
the least powerful Delta II 732010C configuration. It had nine
GEM 40 solid rocket motors ofwhich six were ground lit andthree air lit after the burnoutof the six. Besides touting its
98.7% success rate, this is oneof the most accurate rockets
in regards to placing a payload
in a precise orbit, which it did
with NOAA-20. The NOAA-20
orbit is the same polar orbit
as NPP and proceeds it by 50
minutes with a local crossing
time of 1:30 pm. This was the154th Delta II rocket since its
first flight in February 1989
Delta II primed for take-off
and the second to last, with the
Photo: Ed Murashie
final one scheduled to launch
ICESAT in Sept 2018 from Vandenberg AFB.
Hitching a ride, mounted to the second stage with JPSS‑1,
were four CubeSats. MakerSat-0 from the Northwest
Nazarene University in Idaho is a proof-of-concept mission
with the second mission being the 3D printing, assembly

As with fixed priced contracts, a few features were dropped
on NOAA-20, including search and rescue capability,
space environment monitoring and the Low Rate Datatransmission that we amateurs could have received.
What is included are the suite of five instruments, raw
data transmissions to the TDRS satellites, the Svalbard(Norway) and McMurdo (Antarctica) stations at 8.215 GHz
300 MBps and a data subset at 7.812 GHz 15 MBps
through the High Date Rate channel, HRD. Data will
be available to the users through the data distribution
center, data archive or direct broadcasts. The improved
sounder data will improve the prediction models andnarrow the uncertainty cone of hurricane paths. The low
light capability of the VIIRS has already proven usefulon the Suomi NPP in monitoring the power outages ofPuerto Rico after Hurricane Maria (see overleaf). VIIRS
data will help improve early fire detection and lead to more
efficient deployment of firefighters and equipment. After
Suomi NPP’s and JPSS’ operational lives are over they willbe the first weather satellites to be de-orbited instead ofcontributing to space junk.
Earlier a few NASA questions were asked; here are theanswers. The ozone hole was shown to be smaller over the
past years. As for the growing season it has lengthenedin the northern hemisphere over the past few decades.
For the radiation budget balance, the earth has taken inslightly more energy than it has radiated out. That energy
has been shown to be stored in the top layer of the oceans.
I want to thank NOAA for the invitation to their briefing
and reception and to ULA and Ball Aerospace for handouts
which helped in this article. I want to especially thankMichael Stonecypher, 30th Space Wing Public Affairs
Officer at Vandenberg AFB, for allowing me to attend
the press briefings, tower rollback and launch attempt.
Without his help I would not have the information andphotos used in this article.
Finally as NPP was renamed Suomi NPP to honor Verner
Suomi, NOAA-20 is carrying a plaque with the namesof seventeen people who significantly contributed to theproject but passed away before it launched. Also the fixedmobile launch tower had a banner with the name of two
ULA colleagues who recently passed away. The hope isthat the relatives of these folks know the dedication their
loved ones put into this satellite will lead to saving lives.

www.geo-web.org.uk

45

GEO Quarterly No 56

The Group for Earth Observation

Photographing the Launch
One of the things that interested me at the launch pad
besides the rocket were the remote camera set-ups
left there by members of the press. There were set-ups
like this one from a 20 year veteran who had a custom
enclosure with a small cover that flipped down exposing
the lens at launch and sound triggered to a first-timer who
had a small camera with no protection.

December 2017

The two images below show lighting around the capital,
San Juan. The upper image shows the city lights on a
typical night prior to Maria making landfall, based upon
cloud-free and low moonlight conditions. The lower image
shows the identical region after the hurricane had passed.

The city lights of San Juan, capital of Puerto Rico, show brightly inthis image taken prior to the devastation caused by Hurricane Maria
NASA Earth Observatory image by Joshua Stevens, using data courtesy ofMiguel Román, NASA GSFC, and Andrew Molthan, NASA MSFC

An automated camera used to photograph the JPSS-1 launch
Photo: Ed Murashie

Everything had to be thought through from the stakes thatheld down the tripod to the exposure settings. They were
set up near the pad about seven hours before the launchand picked up three hours after it. If given the chance I
will try my own setup at a future launch.
Puerto Rico City Lights
After Hurricane Maria tore across Puerto Rico lastSeptember, it quickly became clear that the destruction
would pose daunting challenges for first responders.
Most of the electric power grid and telecommunications
network was knocked offline. Flooding, downed trees, andtoppled power lines made many roads impassable. Being
able to know exactly where the power was out would allow
better deployment of rescue and repair crews and those
distributing life-saving supplies.
Although all this happened before NOAA 20 became
operational, Suomi NPP carries an identical complement ofsensors and was able to acquire before-and-after imagesof Puerto Rico’s nighttime lights, thanks to the satellite’s
VIIRS ‘day-night band’, which detects light in a rangeof wavelengths from green to near-infrared, includingreflected moonlight, light from fires and oil wells, lightning,and emissions from cities and other human activity.

46

Widespread power outages are apparent in this image of San
Juan after the passage of Hurricane Maria, a composite createdfrom data taken on the nights of September 27 and 28 tominimise the intrusion of cloud.

NASA Earth Observatory image by Joshua Stevens, using data courtesy ofMiguel Román, NASA GSFC, and Andrew Molthan, NASA MSFC

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

NASA Earth Observatory

An unnamed salt glacier in southeast Iran

Astronaut photograph ISS052-E-8401 was acquired on June 24, 2017, with a Nikon D4 digital camera using a, 1150 millimetre lens, andis provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center.

The scale and form of many impressive features on Earth’s
surface can only be fully appreciated through an overhead view.
Astronauts onboard the International Space Station may enjoy
the best overhead view of all.
The Zagros Mountains of southeastern Iran are the location ofnumerous salt domes and salt glaciers, formed as a result of thedepositional history and tectonic forces that have operated in theregion. While many of these landscape features are named onmaps, the salt glacier in this photograph remains unnamed on
global maps and atlases.
The vaguely hourglass-shaped morphology of the salt glacier isdue to the central location of the salt dome, which formed within
the central Zagros ridge crest. Salt extruded from the dome andthen flowed downslope into the adjacent valleys. For a senseof scale, the distance across the salt glacier from northwest to
southeast is approximately 14 kilometres.
Much like what happens in flowing ice glaciers, concentric
transverse ridges have formed in the salt, perpendicular to theflow direction. While bright salt materials are visible in stream
beds incising the salt glacier, older surfaces—those farther fromthe central salt dome—appear dark, most likely due to windblown
dust deposition over time or incorporation of sediments in the salt
during flow.

Another view of the salt glacier, acquired by ESA’s
Sentinel-2A on October 4, 2017

Image: Modified Copernicus data © ESA / Sentinel (2017)www.geo-web.org.uk

47

GEO Quarterly No 56

The Group for Earth Observation

December 2017

NASA Earth Observatory

Figure 1 - The Aral Sea Basin on August 22, 2017

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

What remains of the large inlandlake is a fraction of what it was in
the 1950s and 60s. In those years,
the government of the former Soviet
Union diverted so much water fromthe Amu Darya and Syr Darya—
the regions’s two major rivers—toirrigate farmland, that it pushed thehydrologic system beyond the pointof sustainability. During subsequent48
48

decades, the fourth largest lake in theworld has shrunk to roughly a tenthof its former size and divided into
several smaller bodies of water.
Figure 1, captured by the Moderate
Resolution Imaging Spectroradiometer(MODIS) on NASA’s Terra satellite,
shows the Aral Sea in central Asia on
August 22, 2017. While the lake waswww.geo-web.org.uk

much smaller in August 2017 thanit was in the 1960s, some growth in
the eastern lobe of the South Aral
Sea represents an improvement overAugust 2014, when that lobe wascompletely dry.
Instead of pooling in one large basin,water flowing down the two rivers now
ends up in either the North Aral Sea

December 2017

The Group for Earth Observation

GEO Quarterly No 56(fed by the Syr Darya) or theSouth Aral Sea (fed by Amu
Darya). The Kok-Aral dikeand dam, finished in 2005,
separates the two water bodies
and prevents flow out of theNorth Aral into the lowerelevation South Aral. The dam
has actually led fisheries in
the North Aral Sea to rebound,even as it has limited flow into
the South basin.
Managers use a sluice gate tolet some water flow from theNorth Aral into the South Aral.
During wet and snowy years,
these releases are common,in dry years, they are rare.
In 2017, heavy outflow fromthe North Aral in the winter,spring, and summer caused
the eastern lobe of theSouth Aral to partially refill,
explained Philip Micklin, ageographer emeritus from
Western Michigan University.
Large releases from theToktogul Dam, a reservoir ona tributary of the Syr Darya,increased the flow of theriver during the winter. In
the spring, unusually warm
temperatures melted enoughsnow pack and glacial ice in
the Tien Shan mountains tokeep the river high. To a lesser
degree, flow from the Amu
Darya may have contributed
to the partial replenishmentof the eastern lobe in 2017 as
well.

Figure 2 - The water pathway from the mouth of the Syr Darya, past Tsche-Bas Gulf to he Southern Aral
NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey

Figure 2 and figure 3 show
the pathway water follows as
it flows down the Syr Darya,
into the North Aral Sea, andeventually the South Aral Sea.
The Operational Land Imager(OLI) on Landsat 8 collected
the image on August 5, 2017.
At the time, the sluice gates atthe dam appeared to be open,
and water was flowing past
the Tsche-Bas Gulf and into
the South Aral.
“However, this year’s events do
not signal a restoration of theeastern lobe as a permanentfeature,” said Micklin. “Since
the early 2000s, the eastern
lobe revitalises during
heavy flow years and thendries completely, or nearlycompletely in low flow years. I
see this process continuing forthe foreseeable future.”

Figure 2 - Detail showing the Syr Darya delta where it enters the North Aral Sea and the Kok-Aral Dam
NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey

www.geo-web.org.uk

49

GEO Quarterly No 56

The Group for Earth Observation

December 2017

NASA Earth Observatory
Observations during 2017 have shown that the ‘hole’ in Earth’s ozone layer—which forms
over Antarctica at the end of each southern winter—was the smallest on record since 1988.

Figure 1
The Antarctic ozone hole, at its annual
maximum extent, on September 11, 2017.

According to NASA satellite estimates, the ozone hole reached
its annual peak extent on September 11, 2017 when it spread
across 19.6 million square kilometres, an area about 2.5 times
the size of the United States. Ground- and balloon-based

50

measurements from the National Oceanic and Atmospheric
Administration (NOAA) agreed with the satellite measurements.
The average area of ozone hole maxima since 1991 has beenroughly 26 million square kilometres.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

The map opposite (figure 1)
shows the Antarctic ozone holeat its widest extent for the year,
as measured on September 11.
The observations were made by
the Ozone Monitoring Instrument(OMI) on NASA’s Aura satellite.
“The Antarctic ozone hole was
exceptionally weak this year,”stated Paul Newman, chief
scientist for Earth sciences atNASA’s Goddard Space Flight
Center. “This is what we would
expect to see given the weather
conditions in the Antarctic
stratosphere.”
The smaller ozone hole in 2017
was strongly influenced by an
unstable and warmer-than-usual
Antarctic vortex, a low-pressure
system that rotates clockwise in
the atmosphere over far southernlatitudes (similar to polar vortices
in the northern hemisphere). The
vortex helped to minimise theformation of polar stratosphericclouds (PSCs); the formation andpersistence of PSCs are important
precursors to the chlorine andbromine reactions that destroyozone.
Although warmer stratosphericweather conditions have reducedozone depletion during the past
two years, ozone holes are still large
because atmospheric concentrations ofozone-depleting substances (primarily
chlorine and bromine) remain high enoughto produce significant yearly ozone loss.
The smaller ozone hole extent in 2017is due to natural variability and is notnecessarily a signal of rapid healing.
First detected in 1985, the Antarctic
ozone hole forms during late winter in theSouthern Hemisphere as returning sunlightcatalyses reactions involving man-made,chemically active forms of chlorine andbromine. These reactions destroy ozone
molecules in the stratosphere. At highaltitudes, the ozone layer acts like anatural sunscreen, shielding the Earth’s
surface from harmful ultraviolet radiationthat can cause skin cancer and cataracts,
suppress immune systems, and damage
plants.
Thirty years ago, the international
community signed the Montreal Protocol
on Substances that Deplete the Ozone
Layer and began regulating ozonedepleting compounds. The ozone hole over
Antarctica is expected to gradually becomeless severe as chlorofluorocarbons (CFCs)
continue to decline. Scientists expect theAntarctic ozone hole to recover back to1980 levels by 2070.

Figure 2
The Antarctic ozone hole, at its annual maximum concentration, on October 12, 2017.

Figure 2 shows the Antarctic ozone holeon October 12, 2017, as observed by
OMI. On that day, the ozone layer reached
its annual minimum concentration, whichmeasured 131 Dobson Units, the mildest
depletion since 2002. (One Dobson Unit
equals the number of ozone molecules
required to create a layer of pure ozone
0.01 millimetres thick at a temperature of
0°C and a pressure of one atmosphere.)
As both images show, the word hole is not
literal; scientists use it as a metaphor forthe area in which ozone concentrations
drop below the historical threshold of 220
Dobson Units. During the 1960s, long
before the Antarctic ozone hole occurred,
average ozone concentrations above theSouth Pole ranged between 260 and 320
Dobson Units. Globally, the ozone layer
today ranges from 300 to 500 Dobson
Units.
“In the past, we’ve seen ozone
at some stratospheric altitudes
go to zero ozone by the end of
September,” said Bryan Johnson,
NOAA atmospheric chemist. “This
year, our balloon measurementswww.geo-web.org.uk

showed the ozone loss rate stalledby the middle of September andozone levels never reached zero.”
Editor’s Note: The uneven seam in thecontours of the data (lower left quadrantof each image) marks the location of theinternational date line. Ozone data aremeasured by polar-orbiting satellites thatcollect observations in a series of swaths
over the course of the day. The passes
are generally separated by about 90
minutes. Stratospheric circulation slowly
shifts the contours of the ozone holeduring each 24 hour period (just as winds
shift the location of clouds). The contours
move little from any one swath to the next,
but by the end of the day, the cumulative
movement is apparent at the date line.
Credits
NASA Earth Observatory images by Jesse
Allen, using visuals provided by the NASA
Ozone Watch team.
Story by Katy Mersmann, NASA GSFC,
and Theo Stein, NOAA Office of Oceanicand Atmospheric Research, with Mike
Carlowicz, Earth Observatory.

51

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Ed Murashie
By the time you read this, GOES-16 will still be drifting to 75.2°W
or will have reached its destination. The milestone dates for thetransition of GOES-East operations from GOES-13 to the newgeneration GOES-16 are as follows:• November 30: HRIT/EMWIN from GOES‑16 will be shut off
while drifting eastward.
• December 5: GOES‑13 GVAR will also be broadcasted
through GOES-14 at 105°W.
• December 11: GOES‑16 will stop its drift at 75.2°W.
• December 14: At approximately 1530Z GOES 13 will turnoff the LRIT and GVAR transponders.
• December 14: At approximately 1545Z GOES 16 will turnon the HRIT transponder and the ground system will start
broadcasting HRIT/EMWIN as the operational GOES Eastsatellite.
• January 2: GOES 14 will turn off the GVAR transponder.
To get on the GOES-R HRIT/EMWIN Broadcast Status email list
contact Seth Clevenstine, NOAA Direct Broadcast Manager, atseth.clevenstine@noaa.gov
Reception of GOES-15 LRIT (Low Rate Information Transmission
at 1691 MHz and 128 kBps) and GOES-16 HRIT (High Rate
Information Transmission at 1694.1 MHz and 400 kBps) arewithin the capability of the amateur community. Having received
GOES-13 and GOES-15 LRIT, it will be interesting to see the
HRIT products from GOES-16 with its advance capability.
My previous LRIT system is described at
http://proengineered.com/
lrit0501/lrit0501_002.htm
My current homebrew system starts with a six foot dish on a
Pelco PT1250P/PP pan-tilt mount. The six foot dish is more than

The author’s six foot dish on its Pelco PT1250P/PP pan-tilt mountThe satellite modem / FPGA formatter card / PC that comprise the author’s system

52

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

This is a GOES-13 image, received by the author, showing the darkening due to the total solar eclipse of August 21, 2017

I need but eliminates the need for error correction, and the Pelco
unit allows the dish to point at either GOES satellite or track polarsatellites. The signal enters a feed horn with two 90° probes
connected to a Mini-Circuit quadrature combiner for right handcircular polarization (RHCP). RHCP is optimum for receiving
polar satellites and helps with the linear polarization differences
between GOES‑East and -West. If you were only intending toreceive one GOES satellite, it would be better to use a smaller
dish with a linear feed.
The output of the combiner goes to a kit-built Sam Jewell G4DDKvery low noise 1.7GHz amplifier (34 dB gain with a 0.24 dB noise
figure). Next is a Mini-Circuits ZQL-1900LNW amplifier withan additional 28 dB gain to drive the 50 feet of LMR-400 coax
cable running into the house. Once inside the house the signal
passes through a 1685 MHz bandpass BSC Filter that is 20 MHz
wide to eliminate local radar noise and then into a CDM-IP-300L
Comtech satellite modem. The modem displays a GOES-13
received signal strength of -63.5 dB, a signal to noise ratio of
12.5 dB, a raw bit error rate of <3.0E-5 and a Viterbi corrected
error rate of <1E-12. The output of the modem goes to a FPGA
frame formatter which is described on my website and then to a
notebook PC through a USB connection.

This Full Disk GOES-13 LRIT image shows Hurricane Irma
to the left and Hurricane Jose on September 9, 2017

Every few years I enjoy lecturing at the Satellite Educators
Association Conference at Cal State Los Angeles. I describe
the satellites, how to get the data on the Internet and then how
to assemble an APT station. It was fun finding the parts for the
homebrew LRIT system and assembling the station but it is not
appropriate for the school teacher audience. But this year might
be different. Lucas Teske (www.teske.net.br/lucas/) with his Open
Satellite Project and Joe Steinmetz (http://usa-satcom.com/)have inspired me by decoding the GOES LRIT signal with a $85
grid antenna, SPF5189 LNAs and the Mini Airspy SDR dongle.
All of these components are readily available. Time to clear off
the workbench and start a new project.
To finish my story, I was sitting around waiting for the recent solar
eclipse which had a 50% chance of being obscured by clouds.
I was thinking about my options when I realized it would be fun
to fire the LRIT system back up and watch the moon’s shadow
on the Earth, so I reassembled the system and captured a few
images. I kept it running through the hurricane season and thenkept the excitement going by attending the JPSS-1 launch. Now I
am looking forward to decoding GOES with the mini‑Airspy SDR
dongle and checking out the new GOES-16 HRIT images. So forme there is as much fun working with the satellite hardware as
there was decoding WEFAX.
On a final note, it was thanks to the polished versions of my GEO
articles, thanks to editor Les Hamilton—which I showed off whentrying to sell myself to Vandenberg AFB—that led to me actually
being invited to the JPSS‑1 launch as a member of the press.

A GOES signal being received by the Satcom XRIT demodulator

www.geo-web.org.uk

53

GEO Quarterly No 56

The Group for Earth Observation

December 2017

NASA Earth Observatory

Astronaut photograph ISS051-E-12977 is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit,
Johnson Space Center. The image was taken by a member of the Expedition 51 crew.

On April 13, 2017, an astronaut aboard the International Space
Station focused a Nikon D4 digital camera fitted with an 1150 mm
lens on the Bosphorus, the strait which famously divides Europe(lower half of the image) from Asia (upper). Turkey’s largest city,
Istanbul, flanks both shorelines. Forested parks at lower left
contrast with the red roof tiles of the cityscape, one of the moststriking features of Istanbul when viewed from space. Two of thethree bridges that span the Bosphorus appear in this image—the
Bosphorus Bridge (right) and the Fatih Sultan Mehmet Bridge(left), the latter named after Mehmed the Conqueror.

The Bosphorus enables significant amounts of international
shipping to move between the Mediterranean Sea and theBlack Sea and if especially important as an outlet for Russian
oil products. In this photograph, a few ships are visible in thewaterway. At several points they need to make dangerously
sharp turns, with coastlines obstructing visibility. This is especiallytrue at Yeniköy and Kandilli Point. Navigation is made morehazardous because currents can reach up to four metres per
second. The risks of navigating the Bosphorus are multiplied by
the heavy ferry traffic linking the European and Asian shores.

Highways lace the city, connecting clusters of high-rise buildingsthat stand out from the tiled roofs, and which cast more shadow
than shorter buildings. Taksim Square is the centre of modern
Istanbul, appearing as an open space near the Dolmabahce
Palace, the administrative heart of the Ottoman Empire in prerepublic centuries.

To reduce the number of ships and to improve safety in thisnarrow waterway—just 1050 meters wide at the Bosphorus
Bridge—officials have proposed to dig a new waterway, theKanal Istanbul, which would connect the Mediterranean andBlack Sea at a point 70 kilometres to the west of Istanbul.

54

www.geo-web.org.uk

André T’Kindt captured this NOAA 18 image from his base in Ronse, Belgium at 08:48 UT on November 10, 2017. Application of an infrared
precipitation overlay illustrates heavy rainfall over eastern France, with the threat of rain approaching England for the following day.

www.geo-web.org.uk

55

GEO Quarterly No 56

The Group for Earth Observation

December 2017

John Tellick
Hurricane Ophelia, the eastern-most Atlantic hurricane everrecorded, was the tenth consecutive hurricane—and the sixth
major one—of the very active 2017 Atlantic hurricane season.
Several islands in the Caribbean were devastated in quick
succession by Hurricanes Irma and Maria, and finally Ophelia.
Ophelia had non-tropical origins south of the Azores on
October 6 from a decaying cold front. Located within a favourable
environment, the storm steadily strengthened over the following
two days, drifting north and then south-eastwards before becoming
a hurricane on October 11. After fluctuating in intensity for a day,
Ophelia finally strengthened into a major hurricane on October 14,
brushing the archipelago with high winds and heavy rainfall as it
started migrating over progressively colder waters to its northeast.
This caused Ophelia to start weakening as it progressed towards
Ireland and Great Britain early on October 16, when, now reduced
to an extra-tropical cyclone, Ophelia became the second storm of
the 2017–18 UK and Ireland windstorm season.
In the Republic of Ireland, a national emergency was declared as
winds of up to 120 kilometres/hour ravaged the country, claiming
three lives and causing extensive damage to properties. All
schools were closed for two days as a precaution as the nation’s
worst storm for over 50 years damaged power networks (overthree hundred thousand consumers were cut off) and caused
widespread disruption to travel as many businesses remained
closed for the day. Over much of Great Britain and Northern
Ireland, a yellow weather warning was issued with forecasts ofwinds gusting up to 100 kph. Early the following day, the cyclone
crossed the North Sea and struck western Norway with wind gustsof up to 70 kph in Rogaland county, before weakening during thatevening. The system made additional landfalls in Sweden and
Finland, before dissipating over Russia.

Figure 1 - The Red Sun, photographed by the author at approximately
11:50 GMT in the morning

The Red Sun.
Here in SW London, on October 16, whilst Ophelia was raging off
the west coast of Ireland, the day started sunny and warm withlight winds. I was checking tree shadows and solar outage on
my EUMETCast dish, gradually aware of the sky becoming milky
with thin high cloud, but still ‘sunny’ though with an increasing‘pinkness’

Figure 2 - The red sky over the river, photographed by the author

I went off to Kingston-upon-Thames around midday for lunch by
the river, the sky becoming increasingly cloudier, and the sun
increasingly red. Almost as the minutes passed, it became darker
and darker with the sky turning a red/brown colour creating a reallycreepy atmosphere. One really felt that the Four Horsemen of the
Apocalypse were about to appear out of the cloud.
Everywhere took on a deep sepia tinge with colours of buildings
and trees being distorted. It became so dark around 13:30 GMT
that street lamps came on and cars used their headlights. It
was quite an experience and very eerie. The unusual and rather
alarming Red Sun phenomenon lasted for several hours, wellinto late afternoon, but that apart, London, at least, was calm andwarm all day.
As will be seen from the Metop-A RGB visible image on that day(figure 4), Ophelia had earlier picked up Saharan dust blowing in
the Atlantic from North West Africa and later smoke from forest
fires in Portugal and Spain. This appears to be evident heading
north in the Bay of Biscay on the image.

56
56

Figure 3 - The track of Ophelia from the Azores to Scandinavia

Image created by Brenden Moses using WikiProject Tropical cyclones/Tracks.
The background image is from NASA. Tracking data is from NHC.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

Figure 4 - This false colour Metop-A image dating from 10:31 UT on October 16 shows a plume of sand being drawn from the Moroccan Sahara
Image © EUMETSAT (2017)

The points on the track map of Hurricane Ophelia(Figure 3) show the locations of the storm at 6-hourintervals. The colour of each marker represents
the storm’s maximum sustained wind speeds asclassified in the Saffir–Simpson scale, and theshape of the data points indicates the nature of thestorm, according to the legend at right.
www.geo-web.org.uk

57

GEO Quarterly No 56

The Group for Earth Observation

December 2017

European Space Agency
ESA’s first Earth observation satellite,
Meteosat-1, was launched on the 23rd ofNovember 1977. When it took its placein the sky, it completed coverage of thewhole globe from geostationary orbit andlaid the foundations for European andworld cooperation in meteorology that
continues today.
Weather—and particularly extreme
weather—affects everything we do. Being
able to see the whole disc of Earth allows
forecasters to see developing weather
systems, as well as working out windspeed and direction based on cloud
movements. Atlantic hurricanes appear on
Meteosat images long before they interact
with land, and data from space help topredict their tracks.
Before weather satellites, forecasters
relied on surface observations fromland, ships and buoys, along with some
information about the atmosphereprovided by balloon-borne radiosondes,
kites and aircraft. Satellites provided avast new array of information that, coupledwith new computer models, helped tomake forecasts more reliable for longer
periods.
Meteosat was an important milestone inEuropean cooperation in space. Individual
countries had pioneered monitoringof the ionosphere from space and theEuropean Space Conferences of the
1960s agreed in principle that there should
be a European weather satellite. But it
was not until Meteosat that the potential
for meteorological satellites began to be
fulfilled.
Meteosat was initiated as a French
project, with involvement both from theirCentre National d’Études Spatiales(CNES) and the French meteorologicalservice. At the same time, the European
Space Research Organisation (ESRO),
a forerunner of ESA, was considering
possibilities for polar-orbiting andgeostationary satellites. ESRO decided
on a geostationary satellite, which would
clearly be a duplication of the Frencheffort.
Over a long period of fact‑finding andnegotiation, the foundations were laid
for the Meteosat project to evolve from a
French one to a European one. Rather
than uproot the whole operation from
France, it was decided to establish an

58

Life sized model of the original Meteosat-1 satellite
Image: ESA

ESA office in Toulouse, from where
Meteosat could be developed and guided.
Meteosat-1 lifted off from Cape Canaveral
in Florida at 13:35 UT on November 23,
1977, reached its operational orbit on
December 7, and sent back ts first image
on December 9. It was the first satellite ingeostationary orbit to have a water vapour
channel to track the motion of moisture in
the air.
The new satellite required great
improvements in ESA’s computing power,both for telemetry and for image dataprocessing. From its position over theGreenwich meridian, Meteosat-1 could
www.geo-web.org.uk

scan Earth’s full disc every 30 minutes,
with the data being provided in near-realtime to users.
Since the launch of Meteosat-1, 40 yearsof imagery and derived meteorological
data from it and its successors havehelped to significantly improve weather
forecasting. There are 35 years’ worth of
Meteosat imagery available online and thesatellite’s record of imaging from spaceconstitutes an important body of evidence
in climate science.
Although the early meteorologicalsatellites were not envisaged as tools
for measuring climate change, images

December 2017

The Group for Earth Observationof changes in land cover or polar ice and data on sea-surface
temperatures have become very useful for climate research andmodelling.
There was a gap of almost a decade between the launchof Meteosat‑1 and the official founding of EUMETSAT, theEuropean organisation created to exploit satellite data forweather and climate research with the global community. Today,with clear operational responsibilities and funding, EUMETSAT
has become a global player in satellite meteorology. With thirty
member states, EUMETSAT continues to develop new satellite
programmes in cooperation with ESA.

GEO Quarterly No 56

The Meteosat programme always has one satellite in theoperational position at 0º longitude. Craft of the Meteosat Second
Generation series retained the drum-shaped design of theoriginal, shown on the previous page, although they were twoand a half times larger and offer improved resolution: 12 spectral
channels as opposed to three on the original system, and fasterscanning.
Looking to the future, Meteosat Third Generation is indevelopment, with new capabilities such as lightning detection,
and will guarantee continued European monitoring of theatmosphere from space into the 2030s.

www.geo-web.org.uk

59

GEO Quarterly No 56

The Group for Earth Observation

December 2017

Francis BellYou can visit our GEO website for almost anything you want toknow about the reception of polar orbiting and geostationary
weather satellite images. Also, you can follow GEO news items
on Facebook, Twitter and User Groups from links on our Home
Page atwww.geo-web.org.uk
If you want to join GEO today, which is now free of charge, then
you can find out more about Earth Observation and related topics
by visiting the Group for Earth Observation on Yahoo at
https://groups.yahoo.com/neo/groups/GEO-Subscribers/info
and clicking the Join Group button.

The International Space Station

The following website shows live views from experimental
cameras on the ISS but reception is subject to orbit andcommunication links
http://www.ustream.tv/channel/iss-hdev-payload
For an audio ground link, sometimes accompanied by video frominside the space station
http://www.nasa.gov/multimedia/nasatv/iss_ustream.html
For a full screen image click the bottom right corner of thecamera image.

Predicting Satellite Passes

For satellite prediction times for your own location, visit
http://heavens-above.com/
and click the link ‘Change your observing location’. On the world
map that appears, zoom in to your location and click it. A marker
appears on the map and your location coordinates are displayed
beneath it.
Next, move back to the opening page and click the link ‘Satellite
database‘, and enter tne name of whichever satellite interests
you from the following list (exactly as shown, including space):
NOAA 15NOAA 18NOAA 19
Meteor M2
ISS
Click the ‘Update’ button, then select the ‘All Passes‘ link fromthe information on screen.

Satellite Frequencies

These are frequencies and approximate pass times for polar
orbiting weather satellites for the UK.
NOAA 19137.10 MHz
around 1.00 pm
NOAA 18
137.91 MHz
around 12.00 noon
NOAA 15137.50 MHz
around 4.00 pm
Meteor M2
137.90 MHz
around 9.00 am
Note that these passes are also available at night: just add 12hours. Also note that the times may be plus or minus about 45
minutes according to any specific orbit.
The NOAA satellite signals are FM modulated with a band widthof about 45 kHz. Decoding software for the NOA satellites is60

quite widely available free of charge. Try the WXtoImg programavailable for download fromwww.wxtoimg.com/downloads

European Satellites

The European agencies EUMETSAT and ESA operate a number
of weather satellites in both polar and geostationary orbit. Images
from these satellites are being disseminated continuously 24/7,
so once a EUMETCast receiving station is established there is analmost non- stop stream of incoming images.
What do you need for personal reception at home are• A dish about 85 cm in diameter, or a little larger, together
with a suitable LNB• a good coax connection to a receiver, which is usually next
to a computer• a newish computer with software fast enough to deal with
the incoming data
• a decryption dongle from EUMETSAT• software to display the incoming data.
Once established, such a system will run indefinitely.
Approximate costs are:
• Dish and LNB ‑ be resourceful• Receiver, about £350 from GEO• A licence and dongle from EUMETSAT, £70
Note this is a once only payment.
• Software, around £50, again a one off payment.
Also available is free software for displaying geostationary
satellite images from Rob Alblas in the Netherlands. Visit his
website at
http://www.alblas.demon.nl/wsat/software/index.html
Alternatively try David Taylor’s software which is outstanding
and easy to use, but for which there is a modest charge. David
Taylors web site iswww.satsignal.eu
On the opening page, from the ‘Satellite Tools’ menu, click‘MSG Data Manager’ for an example of available software for
EUMETCast reception. You can download the software andevaluate it for 28 days before deciding to making a payment toregister it. (MSG means: ‘ Meteosat Second Generation’).

Receiving Images via a Software Defined Dongle

Although the NOAA and Meteor satellites can be received on
dedicated—but expensive—receivers, many enthusiasts enjoy
excellent results using inexpensive RTL-SDR dongles costingaround £10. This is particularly so for Meteor M2, whose signals
are digital LRPT.
You will need to download appropriate software to operate yourdongle, and you will find all the help you need in a deteiled,illustrated article on pages 27-32 of GEO Quarterly No 48, which
you can download fromhttp://www.geo-web.org.uk/quarterly/geoq48.pdf
which details all the relevant download links for the SDRsharpreceiving software, Meteor and tracker plugins and Orbitron
tracking program that are required.

www.geo-web.org.uk

December 2017

The Group for Earth Observation

GEO Quarterly No 56

If you find this process daunting, you can download portable
Installation Suites for receiving Meteor fromhttp://leshamilton.co.uk/MeteorLRPTSuite.htm
These are zipped packages containing absolutely everything you
require for Meteor reception. All you have to do is extract them on
to your PC with WinZip. Packages are available for Windows XP,
WIndows 7 and Windows 10. This page also describes the few
actions that you have to do to modify the system: inserting yourstation coordinates into Orbitron, running the Zadig program
to instal drivers for the dongle and fine‑tuning the frequency in
SDRsharp.
Note that, once you have installed USB drivers for your dongle, it
is recommended that you should always use the same USB port
for live signal reception.

Space:UK

The publication ‘Space:UK’ is available free of charge. Just email
info@ukspaceagency.bis.gsi.gov.uk
stating that you would like to receive a printed copy of‘Space:UK’, providing your full name and address, and statingthat you wish the publication for personal use. For a morecomprehensive view of UK space activities visit
https://www.gov.uk/government/publications/space-sector-magazine-spaceuk

Les Hamilton
In GEO Quarterly 54 I explained how to access data from theCopernicus Sentinel-3 satellite. At that time (June this year) you
simply had to visit the CODA web page, apply for a password,and download the data. Now you must access the CODA page
indirectly, from the EUMETSAT Earth Observation Portal athttps://eoportal.eumetsat.int/userMgmt/login.faces
If you already have a username and password for the EO Portal,
input these in the fields provided and click ‘LOGIN’. If not, click
the link ‘NEW USER - CREATE NEW ACCOUNT‘.
After logging in, a new page appears with several options:select ‘COPERNICUS ONLINE DATA ACCESS‘. and you will bedirected to the CODA page. Downloading imagery proceeds as
described in the earlier article.

Front Cover
Illustrating the resolution of images from China’s Feng Yun 3C
polar orbiting satellite, this is a vignette from the image
reproduced in full on page 17.
Image: Harrie van Deursen

Inside Front CoverNASA’s GOES 16 geostationary satellite was launched intoa storage orbit at 89.5°W a year ago, from where it has been
undergoing. Mike Stevens captured this superb colour composite
image on October 30, 2017, created from channels 5, 3 and 2.
On November 30, 2017, GOES-16 is scheduled to begin a drift to
the GOES-East position at 75°W, arriving December 11

Or write a letter, asking to be put in their mailing list forSpace:UK, to their office at
UK Space Agency,
Polaris House,
North Star Avenue, Swindon SN2 1SZ

Images of the Pacific Rim

If you are interested in viewing geostationary images of the
Pacific Rim, the Japan Meteorological Agency has a website
where you can view full disc images (and images of eastern asia)
taken at 10 minute intervals during the previous 24 hours from its
Himawari satellite. These may be viewed as visible, infrared orcolour composites, and there is an option to run animations of 3,
6 or 12 hours duration.

Image © EUMETSAT 2017

Inside Back CoverThis lovely image section from China’s polar orbiting
Feng Yun 3C satellite was captured, using a home-built system,by Peter Kooistra on September 24, 2017. These Feng Yunorbiters rival NASA’s Terra and Aqua satellites, providing up to
250 metre/pixel image resolution.
AHRPT image captured by Peter Kooistra

www.jma.go.jp/en/gms
Images are available to view as ‘small’ (default) or large (1024pixels square), and can be downloaded, if desired, by rightclicking them and selecting the ’Save image as ...’ option.

Back CoverNASA’s Terra satellite observed Hurricane Ophelia as it tracked
northwards towards Ireland on October 16, 2017. Believed tobe the most powerful storm ever in the western Atlantic ocean,the remnants of Ophelia caused devastation throughout the Irish
Republic.
Image: LANCE Rapid Response/NASA/GSFC

Useful Facebook Pages
APT Grouphttps://www.facebook.com/groups/Satellite.apt.group/

EUMETSAT

https://www.facebook.com/eumetsat/

GEO

https://www.facebook.com/groupforearthobservation

ESA

https://www.facebook.com/EuropeanSpaceAgency

NASA

https://www.facebook.com/NASA/NASA Solar System

https://www.facebook.com/nasasolarsystem/

NASA Solar System

https://www.facebook.com/NOAA/UK Space Agency

https://www.facebook.com/spacegovuk/

Werkgroep Kunstmanen

https://www.facebook.com/kunstmanen

www.geo-web.org.uk

61

GEO Quarterly No 56

62

The Group for Earth Observation

www.geo-web.org.uk

December 2017

December 2017

The Group for Earth Observation

www.geo-web.org.uk

GEO Quarterly No 56

63

GEO Quarterly No 56

64

The Group for Earth Observation

www.geo-web.org.uk

December 2017