the earth as a work of art - european...

This issue, produced in cooperation with theHelmholtz Association,combines Art andScience in a series of surprising satelliteimages. A world tour in technicolour…

The Earth as a Work of Art

2 research*eu SATELLITE SPECIAL I SEPTEMBER 2007

The Betsiboka Estuary,Madagascar

The port of Mahajanga on thenorthwest coast of Madagascar isbecoming increasingly siltedbecause the inland forests arebeing cut down. The wood isneeded as fuel, while the clearedforest areas serve as farmland.However, without the protectivefunction of the trees, the heavymonsoon rains wash away the topsoil layer. New paddy fields silt upwith sediment and the soil iswashed into the River Betsibokaand from there into the Bay ofMahajanga, where bush andbrushwood islets form (red andgreen) and obstruct shipping.

Source Top: USGS, EROS Data

Center

Bottom: NASA

Satellite Landsat-7 ETM+

Date 2000

Altitude 705 km

Technique Visible and near-infrared

light, false-colour image

(above) and true-colour

image (below)

The Altun Shan Mountains,China

The image shows the baremountains on the southern edgeof the extremely arid Altun ShanMountains in North China. The green spots in the top right-hand corner indicate thepresence of metalliferous rock. The large ochre-coloured surfaceis a dried-out salt lake. Salinised

soils lie to the left and right in theirbluish colour. The black line thatextends across the image is a road.At the upper edge, the salt lakecan be recognised as a whiteisland. The People’s Republic of China uses such images togeologically map the country.

Source Top: China RSGS

Bottom: NASA

Satellite Landsat-TM

Date 1995/1996

Altitude 705 km

Technique Visible and infrared light

research*eu SATELLITE SPECIAL I SEPTEMBER 2007 3

Ocean Eddies and Currents

The eddies and currents that formin oceans can only be made visibleby satellite images. The colourindicates the presence of tinychlorophyll-containing algae(plankton) – the staple diet formany fish. The higher thetemperature and the chlorophylllevel, the higher the planktonconcentration (red). Areas withfew nutrients (blue) are colder andcontain less food for the fish. The black areas are the mainland(top) or smaller islands (bottomright). Data like this providefisheries with information onwhere rich fishing grounds lie.

Source NASDA

Satellite IKONOS

Date 1998

Altitude 797 km

Technique Ocean colour in the

visible spectrum

combined with various

infrared areas


Lake Garda, Italy

Italy’s largest lake – Lake Garda(Lago di Garda) – was formed byglaciers during the last ice age.The peninsula at the southern endof the lake accommodates thetown of Sirmione, Roman ruins,and the famous Scaliger Castle(see left-hand side). Satellites seemore than the human eye: thisimage shows only the lakebecause its surroundings havebeen masked out. Digital imageprocessing has been used toenhance the contrast so thatdifferences in sedimentconcentration are clear, allowingconclusions to be made on thequality of the water.

Source NASA, DLR

Satellite Terra/ASTER

Date 21 July 2001

Altitude 705 km

Technique Thermal image highly

contrast-enhanced


Bend of the Spree, and CityCentre, Berlin

The face of the German capital haschanged substantially since theIron Curtain fell. From 1961, the Berlin Wall ran in a north-southdirection through the middle ofthis picture, until the people ofEast Germany tore down theGerman-German border inAutumn 1989. A new moderncentre has developed around the

Potsdamer Platz. The distinctiveroof of the Sony Center andBerlin’s new Central Station areclearly recognisable, even from analtitude of 680 km. The Reichstagand Brandenburg Gate stand inthe centre of the image.

Source European Space Imaging,

DLR

Satellite IKONOS

Date 2 September 2005

Altitude 681 km

Technique True-colour image


Madrid, Spain

Madrid boasts a green heart, the Parque del Retiro, whichappears red in the false-colourimage. Parks and particularly large,open green spaces act like air conditioners for surroundingdistricts during the summer heat.These cool-air islands can be veryeasily observed with satellites andthen taken into account whenplanning new residential areas.

The clearly recognisable roadinfrastructure reveals the variousphases of urban development,from the narrow jumble of oldtown alleys via the linearchequered pattern of later ages through to majorarterial roads and motorways.

Source DLR, NASA

Satellite Terra/ASTER

Altitude 705 km

Technique False-colour image


Kaladan Delta, Myanmar/Burma

Enormous mangrove forests growin the Kaladan Delta in Myanmar/Burma – depicted here in darkgreen. The light green areas areswamps, while the dark dotsrepresent cleared islands. The land is often flooded duringthe monsoon because it lies just a few metres above sea level andtherefore is constantly changing.Such images do more than justproduce and update maps. The data aid important decision-making. Where can a school be built so that it is not flooded during the nextmonsoon?

Source DLR

Satellite SIR-C/X-SAR (Space

Shuttle)

Date 1994

Altitude 450 km

Technique Radar (vegetation

coloured green)


Escondida: The World’s Largest Mine, Chile

Right in the heart of the AtacamaDesert in northern Chile and at aheight of 3 050 m lies the world’slargest copper, gold and silvermine. This open-cast mineproduces 127 000 tonnes of oreevery day. The image on the rightshows the area as we would see it from a plane with our naked eye.But the mine looks completelydifferent in short-wave infraredlight (colour image). This makes itpossible to identify different kindsof rock. Rocks that contain coppershow up through their greencolour. Mined areas are shown in a reddish-beige hue.

Source NASA

Satellite Terra ASTER

Date 23 April 2000

Altitude 705 km

Technique Short-wave infrared light

contrasted to visible light

with near-infrared light


Namib Desert, Namibia

This radar image shows the NamibDesert at Diaz Point near Lüderitz.Only 10 to 20 mm of rainfall peryear are recorded in this region.The violet areas are sand dunesthat extend down to the coast. The orange area is the Atlantic.The narrow band between landand ocean marks the beach. The top right-hand corner showsrocks protruding from the sand.Images like these are used todiscover geological structuresbeneath the desert sand, such assubterranean rivers.

Source NASA

Satellite SIR-C/X-SAR

Date 7 November 1996

Altitude 450 km

Technique Radar


Bathymetry of the North Atlantic

Satellite technology is capable ofreconstructing the processes thattake place beneath the oceansurface and decisively shape ourcontinents, as well as the relief of the ocean floor and its history.This image shows the NorthAtlantic with the volcanicallyextremely active Iceland lying on a central-oceanic ridge. Lavapushes to the surface along thesubmarine mountain ridge and indoing so pushes the continentalplates apart. This is how Europeand America began to drift apart120 million years ago, a processthat continued for 80 million years.

Source DLR, GFZ, USGS

Satellite ERS-1 and bathymetric

measurements

Altitude 782 km

Technique Bathymetric model

shown in perspective

Storm Front Lothar/NOAA-14 AVHRR

The dynamics and power of a low-pressure system are clearlyvisible here. Around Christmas1999, storm front Lothar racedacross France, Switzerland andGermany. Around 100 peopledied, more than 100 million treeswere uprooted. Insured damagevalue: some € 3 billion. Satellitetechnology allows ever moreprecise forecasting and socontinually optimizes measures toprotect against weather disasters.Geostationary satellites likeMeteosat or NOAA-14 AVHRR keepa wary eye open for us on theweather on Earth and so provide a basis for early warning systems.

Source DLR

Satellite NOAA-14 AVHRR

Date 25 December 1999

Altitude 833 km

Technique Thermal infrared


The “Bull’s Eye” – a Landmark forAstronauts, Mauritania

With a diameter of just under 50 km, the unmistakable Bull’s Eye– actually the “Richat Structure” – is an important landmark forSpace Shuttles. Once they haveflown over it, the astronauts knowthey will soon be landing at CapeCanaveral. Initially, researchersthought the structure was theresult of a meteorite impact.Today, they think it is a plutonite, a magna flow that cooled andsolidified under the earth’s surface.Surface soil has been washedaway by the rain and the hard rocknow protrudes as a plateau.

Source USGS, EROS Data Center


Date 7 October 2000

Altitude 705 km

Technique The b/w channel

combined with colour

and infrared channels

The Ngorongoro Crater,Tanzania

This image was shot over theSerengeti National Park. The collapsed crater – a caldera –of the Ngorongoro Volcano can beseen in the centre of the picture.The Ngorongoro Game Reservelies in this caldera. The lakes havebeen coloured dark blue, while hills, mountains andexposed rocks are shown inbrown. The dry vegetation of the lower-lying savannah is givena light blue hue. It’s more humid in the crater and so there is alsomore foliage, which is showngreen. Pictures like these are usedby the nature park administratorsto monitor how the vegetation is developing in the park.

Source GAF

Satellite Landsat TM

Date August 1995

Altitude 705 km

Technique Visible spectral range

combined with infrared

channels


Virtual Panorama – the Alpine Arc, in Perspective

Many different sources, including satellite-basedmeasurements, delivered data for this digital elevationmodel that displays the whole Alpine Arc with consistentquality. Each height gets a colour, ranging from dark green(lowlands) via light green, yellow, ochre, brown through to heights of around 3 000 m shown in dark brown. Heights above 3 000 m or so appear white. Drawn in perspective and artificially lit, the pseudocolouredelevation model becomes more three-dimensional throughthe interplay of light and shadow.

Source DLR, ESA

Satellite ERS-1, ERS-2, SRTM

Date ERS: 1995-1996; SRTM: 2000

Altitude 782 km or approx. 300 km

Technique Computer generated perspective view from

pseudocoloured digital elevations model

Agriculture in Kansas, USA

The image shows meadows andfields. A centre-pivot sprinkler arm up to 400 m long rotates toirrigate the farmland. The coloursindicate how moist the soil is andalso whether cereal or vegetablecrops are being cultivated. Green, irrigated wheat fieldsprobably lie where the infraredlight reflects most (red circles),while brownish circles depictfallow fields or areas where theseeds have not yet sprouted.Green circles are mainly meadowsand pastures. Such images make it possible to estimate theexpected harvest yield for the year.



Date 1 November 2001

Altitude 705 km

Technique Combination of various

spectral bands in the

visible and infrared

spectrum


Farming in Castilla-La Mancha,Spain

Despite difficult climaticconditions, intensive farming hasdeveloped to the south-west ofAlbacete, in the Spanish provinceof Castilla-La Mancha. The maincrop consists of cereals. Irrigatedfields are seen as circles made by a centre-pivoted irrigation system.The red colour is produced byusing false colours – the moreintensive the red, the healthier the vegetation. At one metre perpixel at ground level, the image’sresolution is extremely high for a satellite picture.

Source European Space Imaging,

DLR

Satellite IKONOS

Altitude 681 km

Technique Near-infrared,

false colour image


The Earth at Night

The sleepless planet – oceans oflight wherever heavily built-upareas lie. Yet, brightness does notnecessarily reflect populationdensity. India and China with theirbillions of people are relativelydark. By contrast, the United Statesis wasteful in its use of electriclight. Even sparsely populatedareas are relatively bright.Originally, this kind of earthobservation was used for acompletely different purpose.During the Cold War, the UnitedStates used such imagingmethods to monitor night-timemissile launches.

Source DLR, NASA

Satellite DMSP OLS

Altitude 833 km

Technique Combination of visible

and thermal infrared

light, underlayed with

a world map


The Lambert Glacier, Antarctica

The Lambert Glacier in EastAntarctica is the world’s largest. It is more than 400 km long andjust under 50 km wide. An icefallmeasuring 400 m from top tobottom feeds the glacier (upperhalf of the picture). At the coast,the glacier pushes out to the sea.The shelf ice is thus mainly freshwater. The giant icebergs that driftin the polar seas are pieces thathave broken away from suchglaciers. Red tones in the lowerhalf of the image show the cliffsthat protrude from the glacier.



Date 2 December 2000

Altitude 705 km

Technique Visible light

Glacial Retreat, Chile

This false-colour image shows the great San Quintin Glacier in southern Chile. The ice extendsdown to the lowlands, the flankingvegetation is shown red. Theglacial tongue flows into a lake(left-hand edge), surrounded bythe terminal moraine that theglacier pushes ahead of it.Mountain glaciers respond muchmore quickly to temperaturechanges than polar glaciers. Someglaciers in the Andes have alreadybecome much smaller. The centreof the image shows an area thatwas still largely covered by ice in 1994.

Source NASA

Satellite Terra ASTER

Date 2 May 2000

Altitude 705 km

Technique Visible and near-infrared

light, false colour

technique


Clear View across Europe

The clouds were removed from a satellite image acquired byEurope’s Meteosat andsuperimposed on to a picture ofEurope without clouds. This produced a very realisticcolour impression that could nothave been achieved in such detailwith a “standard” Meteosat image.Meteosat data play a key role in weather forecasting and long-term climate andatmosphere observation. The satellite measures thetemperature of the earth surfaceand the amount of water vapourin the atmosphere and transmitsthe data once every 15 minutes.

Source EUMETSAT,

DLR/Planetary Visions

Satellite METEOSAT/MODIS

Date June 2005

Altitude 36 000 km and 705 km

Technique Image composed of

various sets of satellite

data


The Great Salt Desert: Dasht-e Kavir, Iran

The Dasht-e Kavir lies to the south-east of Tehran and is, withan area of 55 000 km2, one ofEarth’s largest salt deserts. The wind has blown away thesand and exposed the ground rock made up of various layers ofdeposited clay – shown brownhere. The blue shades reveal saltlakes or swamps with a salt crust.The concentric circles show thatthe water evaporated very slowlyhere after earlier floods. Imageslike these are used to producesatellite maps of previouslyunsurveyed regions.



Date 24 October 2000

Altitude 705 km

Technique Visible light (red and

green) and infrared

Traces of War in the Persian Gulf,Iraq/Iran

Traces of military conflicts –viewed from space. This image was shot long after the Iraq-Iranwar (1980 to 1988). The RiverSchatt-el-Arab runs along the left-hand side and forms theborder between Iraq and Iran.Fortified walls and dams line upalong the border in the top right-hand corner. The Iraqis builtthese ramparts in the swamplandsfor their artillery. At the same time,they flooded the resulting ditchesfor further military defence.Images like these were usefulwhen reestablishing farming inthe war zone.



Date 24 January 2001

Altitude 705 km

Technique A b/w photo combined

with colour and infrared

channels


Klyuchevskaya Sopka, Russia

On the sparsely populated RussianKamchatka peninsula stands oneof the world’s most activevolcanoes. Klyuchevskaya Sopka is one of around 500 activevolcanoes in the Pacific Ring of Fire. The Pacific and Eurasianplates collide under Kamchatka.The picture was taken after theeruptions of 30 September 1994.Red areas represent solidified lava. The mud flows of meltedsnow and volcanic ash appeargreenish-blue. These couldthreaten fields and settlementsdown in the valley.

Source NASA

Satellite SIR-C/X-SAR

(Space Shuttle)

Date 5 octobre 1994

Altitude 450 km

Technique Radar, 4 750 m

The Tien Shan Mountains, China

This part of northwest China issparsely populated and wassurveyed in a special missionduring which two satellites flewexactly the same route in tandemexactly 40 minutes apart. This dualsurvey at such a short intervalproduced very precise elevationdata on the region. The colourscorrespond with those ofconventional maps: brown for hillsand mountains, green forlowlands. The three-dimensionaleffect is achieved by additionallyintegrating shadows. Precisionmaps or elevation models of suchremote areas are hardlyconceivable without satellitetechnology.

Source DLR, ESA

Satellite ERS-1 und -2

Date 1999

Altitude 785 km

Technique Radar


Farming on the Edge of theDesert, Saudi Arabia

Arid regions like this on the edgeof the Saudi Arabian Desert canonly be farmed with intensiveirrigation. The two dark circles onthe left-hand edge are irrigatedfields. Groundwater pumped tothe surface is distributed viairrigation systems. The areacoloured in shades of red andorange is a dune landscape. On the right, the mountain ran-ges with their exposed rock havebeen coloured blue. Such imageshelp geologists search forgroundwater in arid zones. They believe that they might beable to find water beneath long-dried-out river beds (wadis) thathave meanwhile filled with sand.

Source DLR

Satellite MOMS

Date December 1996

Altitude 700 km

Technique Visible and infrared light


Mayon, Philippines

Mayon is the most active volcanoon the Philippines – it has eruptedno less than 47 times since 1616.The image was shot from a radarsatellite and shows characteristiccoloured stripes. These correspondwith the elevation lines on mapsand accurately depict the contourlines to within just a few metres.The closer the coloured lines, the steeper the mountain incline.Any changes in height are a suresign of activity within the volcano.

Source ACRoRS, Bangkok

Thailand, ESA

Satellite ERS-1

Altitude 785 km

Technique Radar interferometry

the earth as a work of art - european...

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