Acta Astronautica 57 (2005) 520–533

www.elsevier.com/locate/actaastro

High resolution earth observation satellites and services in the nextdecade–aEuropean perspective

Gunter Schreier∗, Stefan DechGerman Aerospace Centre DLR, German Remote Sensing Data Centre DFD, D-82234 Oberpfaffenhofen, GermanyGerman Aerospace Centre DLR, German Remote Sensing Data Centre DFD, D-82234 Oberpfaffenhofen, Germany

Available online 21 April 2005

Abstract

Projects to use very high resolution optical satellite sensor data started in the late 90s and are believed to be the major driverfor the commercialisation of earth observation. The global political security situation and updated legislative frameworkscreated new opportunities for high resolution, dual use satellite systems. In addition to new optical sensors, very highresolution synthetic aperture radars will become in the next few years an important component in the imaging satellite fleet.The paper will review the development in this domain so far, and give perspectives on future emerging markets and

opportunities. With dual-use satellite initiatives and new political frameworks agreed between the European Commission andthe European Space Agency (ESA), the European market becomes very attractive for both service suppliers and customers.The political focus on “Global Monitoring for Environment and Security” (GMES) and the “European Defence and SecurityPolicy” drive and amplify this demand which ranges from low resolution climate monitoring to very high resolutionreconnaissance tasks.In order to create an operational and sustainable GMES in Europe by 2007, the European infrastructure need to be adapted

and extended. This includes the ESA SENTINEL and OXYGEN programmes, aiming for a fleet of earth observation satellitesand an open and operational earth observation ground segment. The harmonisation of national and regional geographicinformation is driven by the European Commission’s INSPIRE programme. The necessary satellite capacity to complementexisting systems in the delivery of space based data required for GMES is currently under definition.Embedded in a market with global competition and in the global political framework of a Global Earth Observation System

of Systems, European companies, agencies and research institutions are now contributing to this joint undertaking. The paperaddresses the chances, risks and options for the future.© 2005 Elsevier Ltd. All rights reserved.

∗ Corresponding author.E-mail addresses: Gunter.Schreier@dlr.de(G. Schreier),

Stefan.Dech@dlr.de(S. Dech).

0094-5765/$ - see front matter © 2005 Elsevier Ltd. All rights reserved.doi:10.1016/j.actaastro.2005.03.029

1. Very high resolution imaging satellites inoperation and in planning

Since the availability of Russian analogue KVR-1000 space imagery in the early 90s, the limitof geometric resolution of non-classified earth

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observation imagery shifted from the then best res-olution of 10m—captured by the SPOT satellitesto the domain of about 2m per pixel. Similar tothe heritage of the Russian data, such informa-tion was formerly only available for strictly clas-sified military reconnaissance programmes of theformer military super-powers. Since the successfullaunch and operations of Space Imagings IKONOSII satellite (after an initial launch failure) in 1999,this “metric” or even “submetric” resolution is nowavailable on a commercial basis. This domain ofgeometric resolution is often referred to as “veryhigh resolution” (VHR) data. Responding to thechallenge from former Russia, US companies, util-ising technologies developed initially for militarytasks, took the lead in optical metric systems. Mean-while European states and other countries of theworld keep up with providing similar systems andexploring other domains of the electromagnetic spec-trum, such as radar imaging. Besides space agen-cies and entities from the traditionally space faringnations, also satellite operators from “countries intransition” and even from “developing countries”enter the arena. International organisations such asCommittee on Earth Observation Satellites (CEOS)[1] try to keep up to date with the plans of theirmembers, but do not list purely commercial orsome dual-use enterprizes. Additional sources havebeen used[2,3,22] to compile the list of signifi-cant earth observation satellite systems as shown inTable 1.Though, most of the operators or distributors of

these earth imaging systems are private enterprises,still the vast majority of customers for the veryhigh resolution data are governmental entities, espe-cially military and security agencies[2]. To satisfythe increasing need of US intelligence customerson VHR space data on one hand and to reduce thecosts of operations, the US Presidential directive ofApril 25, 2003 further eased previous restrictionson the commercial collection of space imagery anddemanded US federal agencies to purchase satelliteinformation from commercial companies[4]. TheNational Geospatial Intelligence Agency (NGA, for-mer NIMA) awarded a first NextView contract toDigitalGlobe, Longmont, Co, USA, for the deliv-ery of very high resolution space imagery to theUS armed forces. Intentionally, the contract would

allow DigitalGlobe to finance its next generationsatellite system, called WorldView. At the time ofediting this paper, a call for a second NextViewcontract was finished and has been awarded to Or-bimage. With the delay in the deployment of thefuture US military reconnaissance satellites (calledFuture Imagery Architecture, or FIA) and the globalmilitary engagement of US forces, data purchaseagreements such as NextView will stimulate thedelivery of VHR data for quite a couple of years.Besides such governmental data purchase agreement,the rest of the governmental and private customermarket is believed too small to operate such systemsprofitable.The situation for European earth observation satel-

lite systems is only partially comparable to those inthe US. With the French SPOT series, Europe wasonce leading the commercial supply of high resolutionsatellite images. Though also used by military and se-curity forces, the requirements of European militaryforces would not have so far justified the deploymentof commercial operations. European military interestshave been not as global as the US ones and Europeanmilitary budgets are significantly smaller than thoseof its Atlantic ally.Explanation for satellite table on the previous page:

Column Explanation1 C = commercial mission or commer-

cialised outside country of origin;P = public/private partnership betweenspace agency and commercial partner;D = dual use: military and commercial;no sign indicates limited regional or sci-ence availability

6 Capital letters C, L, X denote radarfrequency bands; Q= fully polarised;q = partially polarised; pan= opticalpanchromatic only

7 Numbers denote launch of satellite in aseries; mission end dates are as plannedor estimated; “—” denotes that satellitemight operate longer

8 Numbers of satellites in the mission; spe-cial capabilities are abbreviated

The new geopolitical situation and “asymmetric”threats have changed this picture significantly. New

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Table 1Major earth observation satellites in orbit or in planning

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military engagements require presence of Europeantroops in countries outside Europe. The new Europeanconstitution gives the European Commission a greaterrole in coordination of a “European Foreign and Se-curity Policy” (EFSP) and the procurement of militarysystems. Therefore, a new European Defence Agency[5] has been established in 2004. Since then, nationalclassified earth observation systems have been de-ployed by France and few partner states (HELIOS) andmost recently by Germany (SARLupe with 5 imagingradar satellites, which is due for operations in 2006).Meanwhile, European military agencies also act as

normal customers to the existing and near future sup-pliers of VHR data. Systems, which can satisfy bothcivilian and public needs, have been initiated in Italyand France. The COSMOSkyMed project of Italy isconducted in a partnership with the Italian military andtherefore classified as dual-use. Three X-Band imag-ing radar satellites will form a capability, amendedlater by two optical VHR satellites delivered by asimilar French dual use set-up, the Pleiades system.A French–Italian user preparation program under thename ORFEO has started, which also includes the de-velopment of data evaluation tools[6].Recently, Spain has started a project—named

Tarsis—aimed to complement the Italo–French recon-naissance satellite network by Spanish small satelliteswith optical and radar capabilities (Aviation Week,August 2, 2004).Though, not intended for security and military use,

other commercial earth observation imaging systemsalso value military customers as important clients. No-tably the German TerraSAR-X VHR radar satellitewill offer its polarized SAR modes and phased-arrayantenna flexibility to military and security customersworldwide. TerraSAR-X is done in a public privatepartnership (PPP) between the German Space Agency(DLR) andASTRIUM,Germany. In return for the gov-ernmental investment in the satellite and the built-upand operations of the entire ground segment at DLR,DLR has the right to have access to 50% of the en-tire global satellite capacity for non-commercial, pri-marily scientific investigations. The remaining 50% ofthe imaging capacity will be exclusively sold to inter-national customers and ground stations by InfoTerra,Germany, a subsidiary of ASTRIUM.Another German commercial company, Rapid Eye,

has meanwhile concluded its financial set-up and is

targeted to launch a five satellite based optical system.Though meant for agricultural monitoring and not inthe VHR domain, the high repetition rate of the fivesatellites could be an important factor for some usersconcerned with rapid and most frequent observations.More information on these satellites is given in a sub-sequent chapter.

2. The political drivers and activities in Europe

Using earth observation satellites for securing Eu-ropean security interests was put on the agenda onlyquite recently. European space agencies are primarilyoperated from a science and research perspective andare funded by the corresponding ministries. Only fewagencies belong to ministries in charge for commercialissues (e.g. the British National Space Center) and fewhave links to the national departments of defence (e.g.CNES; the French space agency). Hence, the focusfor earth observation applications in Europe has beenenvironmental and—to some extend—commercial ap-plications. The European Space Agency (ESA) wascreated in 1975 with the mandate for science and re-search for “exclusively peaceful purposes” (Article IIof the ESA Convention)[20]. The ESA earth observa-tion missions are characterised by their intended useand origin. Missions, which are meant to ensure op-erational needs by European institutional customers,are called EarthWatch missions. The first ESA Earth-Watch missions, ERS-1 & 2, carry radar payloads tostudy ocean and ice phenomena and constituents ofthe atmosphere. A more sophisticated radar sensor(ASAR) and even more atmospheric sounders plus awide swath medium resolution imager are put on EN-VISAT, the third ESA EarthWatch mission, now in or-bit.Besides, ESAmanages to acquire non-European/non-

ESA earth observation data for European customers.Such “Third Party Missions” include the NOAA-AVHRR and Landsat-Series of satellites. Under ESAdata policy, all data from the EarthWatch and ThirdParty Missions are classified in two categories: Cat Idata is delivered to scientists (basically for free), uponacceptance of a science proposal. Cat II data is soldthru commercial entities selected by ESA. Currentlythe consortiums SARCOM (lead by SPOT Image,Toulouse, France) and EMMA (lead by Eurimage,

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Rome, Italy) has such commercial sales licences. Itis expected that this Cat II commercial sales scenariowill change by late 2005/ early 2006, when a newESA data policy is put into force.The third category of ESA earth observation

missions—called Earth Explorer—are limited to ad-dress specific geoscientific topics with one dedicatedmission.Besides contributing data and products to geosci-

entific research, ESA had so far limited capabilitiesto fund large research projects. Scientists are askedto apply for funding at their national research spon-soring agencies or the appropriate programmes of theEuropean Commissions. The latter initiated in its 5thand 6th framework programmes thematic areas ad-dressing earth observation issues in “Global Changeand Ecosystems”, “Aeronautics and Space” and “In-formation Society Technologies”. Besides, Europeangovernmental research organisations initiated nationalearth observation programmes such as the ATMOSprogramme in Germany, coordinating applications inthe remote sensing of the atmosphere.What was missing until recently was the coherence

of these various national and European approachesand their focus to operational and sustainable use ofearth observation data and services. The initial at-tempts started in 1992, when the European Commis-sion, in collaboration with ESA, initiated a long termprogramme, lead by its Joint Research Centre (JRC)called the Centre for Earth Observation (CEO)[7].CEO was meant to promote the use of earth observa-tion by user driven demonstration projects, servicesand information exchange using early possibilities ofthe Internet. In a series of events in Europe, it becameclear that an European Earth Observation System(EEOS), as proposed by CEO, need to be based ona broader political consensus, involving further Eu-ropean stakeholders from the Commission, Europeanorganisations, national governments and industry.The idea of a system for “Global Monitoring of En-vironment and Security” (GMES) was subsequentlyborn and officially agreed by a European summit inGothenburg, in June 2001. GMES is jointly set-up bythe European Commission and the European SpaceAgency as an initiative to provide independent, opera-tional and relevant information in support of a range ofprimarily environmental policies serving sustainableobjectives[8]. The “S” in GMES is also meant to sup-

port objectives linked to the implementation of a Com-mon Foreign and Security Policy (CFSP). The GMES“initial period” ran from 2001–2003 and featured acouple of studies and pilot projects as well as “userconsultation meetings” both held by the EuropeanCommission, ESA and national organisations. TheGMES action plan for 2004–2008, both agreed bythe European Parliament and ESA[9], defines thepath for the implementation of a European capacityfor GMES by 2008. A joint ESA and EU GMESAdvisory Council (GAC) and a GMES Project Of-fice (GPO) were set-up in Brussels, Belgium, andan action plan has been defined in July 2004. Oneof the challenging goals is to define the financing ofGMES beyond its initial phases. Among the financ-ing proposals discussed would be a joint undertakingbetween ESA and the Commission, such as installedwith the Galileo satellite navigation system.Parallel to these activities, ESA initiated already

in 2000 the Earth Observation Market Develop-ment (EOMD) programme. Since then EOMD haslaunched more than 40 demonstrator projects in orderto strengthen Europe’s industrial capacity for pro-viding geo-information services, primarily based onearth observation data.

3. GMES services

GMES is defined to be driven by the demands forgeo-information services of its stakeholders. These areprimarily identified in the various European, nationaland regional public services and agencies, which re-quire up-to-date and reliable environmental informa-tion on European and global land, air and sea ar-eas. Depending on the needs of entities such as urbancommunities or the European Environmental Agency(EEA), the region of interest could cover small townsor the entire globe. The utilisation of earth observationdata for several kinds of scientific and pre-operationalneeds was addressed by the European Commissions5th and moreover 6th framework programme on re-search for quite some time. Specifically under theheadline of GMES more than 20 thematic projectsare co-funded by the European Commission. The top-ics of these projects range from land cover changeand environmental stress in Europe, to global vegeta-tion and atmosphere monitoring, support to regional

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Table 2Overview of running ESA GMES Service Elements contracts

Theme Topic Lead URL

Urban services Urban monitoring and development Indra, Spain http://www.gmes-urbanservices.commapping

Forest monitoring Afforestation, reforestation and deforestation GAF, Germany http://gafweb.gaf.de/gsemapping

SAGE Service for Advanced Geoinformation on InfoTerra, Germanyhttp://www.gmes-sage.infoEnvironmental Pressure & State

Risk EOS EO based services for Natural Risks Management Astrium, Francehttp://www.risk-eos.comROSES Real-time Ocean Services for Environment and Security Alcatel, Francehttp://roses.cls.frIcemon Sea ice information in the Arctic Nansen, Norway http://www.icemon.orgNorthern view Ocean and land arctic environment monitoring C-CORE, Canadahttp://www.northernview.orgGMFS Global Monitoring for Food Security VITO, Belgium http://www.gmfs.infoCoastwatch Monitoring coastal environment status EADS, France http://www.coastwatch.info

and land use changesTerraFirma Pan-European ground motion hazard information service NPA Group, UKhttp://www.terrafirma.eu.com

hazard information serviceRESPOND Support to humanitarian aid InfoTerra, UK http://www.respond.eu.comPROMOTE Support atmospheric policy issues KNMI, http://www.knmi.nl/samenw/promote

and climate change monitoring The Netherlands

development aid, risk and crisis management and in-formation technologies. Due to the “shared-funding”approach of the Commission projects, the Commissiondefines the administrative scheme, but leaves the tech-nical management and the development of the furtheroperations and hence the sustainability of the servicesto the project partners.ESA approached the challenge to built sustainable

GMES services by a phased engineering approach. Acall for tender under ESA’s EarthWatch programme in2002 demanded bidders what ESA called “GMES Ser-vice Elements (GSE)” to comply with a required man-agement and extensive document structure. Whereasthe management set-up made sure that real users ofthe delivered geoinformation products are involved inthe project, the documentation tree insured the com-parison between the projects and the tabulation of re-quirements, infrastructure and business plans. For thelatter, the socio-economic benefit is of equal impor-tance as the pure commercial revenue.Table 2givesan overview of the current ESA GSE projects.The ESA GSE also listed the requirements on

satellite information for their services. Medium reso-lution and Landsat-alike optical and ERS-alike radardata is required to service general European map-ping demands for land cover analysis and change,vegetation and environmental monitoring of land and

coastal areas. VHR data both of optical and SARorigin is required, when a more detailed regionalanalysis is demanded as a spot check, or when lo-cal small scale phenomena need to me mapped. TheRESPOND (Humanitarian aid) and URBAN servicesare the leading services in demand for VHR based in-formation (Fig.1). Under the latter several Europeancities—including those of the new European Unionmember states—have been mapped by the pre-cursordemonstration services.By mid 2004, 12 operational GSE projects are run-

ning and 10 of them will finish the first consolida-tion phase by end of 2004. Two—RESPOND andPROMOTE—started a bit later. Following this consol-idation phase, ESA—in co-ordination with the Com-mission funded projects—will select a number of ser-vices in early 2005 to go into full operations by 2007(Fig. 2). While these phases are still funded by ESA,the service partners shall work towards a financingof follow-on operations by the users of this informa-tion. It is clear that the services related to environ-ment and treaty monitoring can only be financed byEuropean or national government level ministries, de-manding the high level information for their admin-istrative work. The medium and high resolution earthobservation data required for these services will, to alarge extend, be delivered by satellite systems owned

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Fig. 1. Urban land use service element; Automated classification ofSPOT-3 data by Definiens Imaging of the City of Riga, Lithuania.

by the public and European entities. The ESA fleet of“sentinel” satellites, described in a following chapteris meant to address this issue.TheVHR data for demands on precise mapping and

local verification will mostly be born out of private orPPP (public private partnership) systems.As described

Fig. 2. GMES services element implementation sequence[10].

in a following chapter, such systems will be estab-lished in Europe in the next years. Here, private opera-tors are asked to recover their costs—if not the costs ofthe entire satellite and the follow-on system—by thecommercial sales of the data. The commercial VHRoperators are expecting larger scale contracts by na-tional and European military entities. But is still un-clear, by which contractual and financial agreementsGMES services will obtain the necessary VHR data.New business models are currently under discussionby the private operators and the GMES entities. Gen-eral data purchase contracts, such as the US NextViewprogramme, servicing military demands, could also beenvisioned to serve European civil and security needs.

4. The security dimension

In its White Paper on Space[11], the Commissionincluded a chapter entitled “Space as a contribution tothe common foreign and security policy (CFSP), theEuropean Security and Defence Policy (ESDP) andto the anticipation and monitoring of humanitariancrises”. Therein, the Commission urges the reinforce-ment of space technologies in support of securityand defence policy requirements. This would requirethe use of existing space-based assets as well as thedevelopment of new ones. The new global securitysituation and the new European Constitution, giving

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the Commission more responsibilities in security, de-fence and foreign affairs form the basis for this inter-est. At the European Council in Thessaloniki, Greeceon June 20, 2003, Javier Solana, now designated “For-eign Minister” of the European Union, presented a pa-per titled “A secure Europe in a better World”[12],which outlines challenges and key threats. An imme-diate action was the initiation of a European DefenceAgency, which is now put in place[5].Specifically on the space and security demands, the

Commission took two further actions in response tothese agreements. Firstly, it has launched a “Prepara-tory Action on Security Research” (PASR). Guided bya high level implementation strategy[13], the 65M¥funded PASR is intended to be the pre-cursor of an atleast 1B¥/year security technologies programme, to beimplemented by 2007, which also includes researchfor satellite based situation awareness and recon-naissance. By June 2004, some 200 proposals fromEuropean entities, proposing critical areas of securitytechnology for PASR have been evaluated by theCommission.Secondly, a joint ESA/Commission/Member States

“Panel of Experts on Space and Security” (SPASEC)has been established in June 2004, in order to con-tribute to the identification of the requirements onspace technology from the security point of view andto determine how Europe and European space organi-sations shall respond to global security issues in gen-eral. A report of this panel is expected by end of 2004.The report will also include the potential mechanismsto use purely military systems, such as the French He-lios and the German SARLupe system, for generalEuropean Community needs.By the mechanisms of the currently running 6th

Framework Programme on research, a “Network ofExcellence” was launched in 2004, which aims to in-tegrate Europe’s civil security research so as to acquireand nourish the autonomous knowledge and exper-tise in Europe for research and applications for secu-rity based on satellite image information. This “GlobalMonitoring for Security and Stability” (GMOSS) Net-work addresses generic methods and algorithms forautomated image interpretation as well as applicationscenarios such as border control, infrastructure map-ping and nuclear treaty monitoring. Managed by theGerman SpaceAgency (DLR), GMOSS integrates ini-tially 25 organisations and companies in Europe will

run for four years[14]. It is intended to develop themesfor future research and institutional actions on spaceand security.

5. European very high resolution satelliteprogrammes

The European White paper on space[11] not onlyconstitutes an autonomous access to space (e.g. theAr-iane launcher programme), but also an independencyin the primary data supply as a strategic objective.Whilst this objective is also a driver for the future Eu-ropean ESA/Commission earth observation satellites(i.e. the SENTINELS), European nations have alreadystarted in the mid 90s to consider either a further pri-vatisation of the imaging satellite business and/or theneed for VHR data for national security and mappingneeds. The main national public programmes/satellitesystems (not the purelymilitary systems) to serve theseneeds are described below.

5.1. TerraSAR-X (Germany)

The merger of some of the largest Europeanaerospace companies resulted in the creation ofEADS and its subsidiary ASTRIUM, responsiblefor all EADS satellite related business. Based onthe experiences with SAR technology from variousESA contracts (ERS, ENVISAT) and the Germannational SAR missions (SIR-C, SRTM) and based oneconomic feasibility and market studies, ASTRIUMand its earth observation application and exploitationunits created the concept of an L-Band and X-BandSAR satellite constellation to serve multiple appli-cation needs of operational users. The financing ofthese satellites was supposed to be guaranteed withcontributions from the governmental sector includingESA.In March 2002, the German Space Agency, DLR,

and EADS ASTRIUM GmbH signed a PPP agree-ment, under which DLR orders from ASTRIUM thedesign, built and launch of an innovative X-Band SARsatellite, called TerraSAR-X. ASTRIUM contributessignificantly to the project and in return receives theexclusive and global commercial exploitation of 50%of the capacity of the satellite. The commercial dis-tribution is managed thru InfoTerra, Friedrichshafen,

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Fig. 3. The TerraSAR-X satellite.

Germany, in cooperation with other partners fromAS-TRIUM, namely Spot Image. The other half of thesatellite data will be exploited for science use by DLRthru an international “Announcement of Opportunity”(AO).The 1023 kg TerraSAR-X satellite delivers X-Band

SAR data in various modes (Fig.3) [15]. The Spot-Light mode will yield the finest resolution data withabout 1m pixel size for a 10 km× 10 km image. TheScanSAR mode delivers 16m resolution at 100 kmswath. All imaging modes offer a full polarisation ca-pability. A special “split antenna” mode will allowexperimental in track interferometry, for instance formapping moving objects. The satellite will fly in a514 km dawn–dusk orbit and is scheduled for launchin mid 2006.A similar PPP agreement between ASTRIUM and

British authorities to ensure the availability of theL-Band SAR counterpart (TerraSAR-L) did not ma-terialise. Instead, further studies on the concept ofTerraSAR-L have been funded thru the ESA Earth-Watch programme. But it is questionable, whetherthese will proceed in the construction of a satellite orwhether it will be amalgated into the ESA SENTINELseries.

5.2. Pleiades (France)

The longest experience in commercial earth obser-vation is gained so far thru the French SPOT pro-gramme. Once the market leader in that domain, thenew VHR satellites of its US competitors gain moreand more ground. Based on user requirements and

Fig. 4. Sketch of the French Pleiades spacecraft.

market studies, the French space agency and Frenchcompanies compiled a list of 10 sensors, which wouldfulfil the market needs[6]. Whilst other data acqui-sition techniques should be addressed in internationalpartnerships, France has considered the VHR opticalsystem as its highest priority. Based on minor contri-butions from other European partners such as Sweden,Belgium, Spain and Austria, CNES confirmed the go-ahead of the phase C/D in 2003 with a targeted launchof the first satellite by 2008 and the second by late2009.Built by ASTRIUM, France as a main contrac-

tor, Pleiades will provide a pan resolution of 0.7mat nadir and four spectral bands with a 2.8m nadirresolution with an image swath larger than 20 km(Fig. 4). The mini-satellite (mass< 1000 kg) has fullagility to allow flexible imaging and stereo modes. A600Gbit mass memory would allow to acquire datafrom global targets, then down linked with 465Mbit/s.A total capacity of 250 images/day should beachieved.As mentioned earlier, Pleiades is planned to deliver

data for civil as well as for military applications and isaugmented in the SAR domain by a strategic alliancewith the Italian COSMO SkyMed programme. On thecivilian side, Pleiades is the French complement to theEuropean fleet of satellites, servicing the needs of theGMES programme.

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Fig. 5. Sketch of the Italian Cosmo SkyMed satellite.

5.3. Cosmo SkyMed (Italy)

Based on the strategy of the Italian National SpacePlan (PSN), the initial focus was to deploy a systemfor environmental observation and natural hazardsmapping for the Mediterranean Basin area. Mean-while, the Italian DoD, who is a minor partner inthe use of the French Helios reconnaissance satellitesystem, was looking for follow-on capabilities. Mod-ifying the requirements of the initial X-Band SARsatellite and launching a strategic alliance with theFrench Pleiades programmes, made COSMO nowa dual use system, now co-funded by the ItalianDoD [16].The Italian national user studies revealed—similar

to the TerraSAR-X/L system—a need for SAR L-Banddata to generate land mapping and land cover prod-ucts. Italy found here a partner in Argentina, whichplans to deploy a two satellite based multipolarimet-ric L-Band system called SAOCOM, developed by theArgentinean space agency CONAE.The COSMO system will feature 4 fully polarimet-

ric X-Band satellites (Fig.5). On board data storageof 300GBit and 300Mbps downlink guarantee globalavailability of the information to the Italian groundsegment (in cooperation with a northern station). Itis reported that the first satellite shall already be de-ployed in 2005 with a completion of the entire con-stellation within two years.

5.4. Rapid Eye (Germany)

RapidEye AG was founded 1998 in Munich asspin-off of the company Kayser-Threde. Based onapplication business experiences there, the idea wasto define a privately owned multi-satellite system for

Fig. 6. The Rapid Eye Satellite[17].

a fast, if not daily—“rapid” coverage of primarilyagricultural areas. Precision farming, hail damage in-surance and agricultural mapping services are amongthe prime application targets. To meet these require-ments, a five satellite constellation, with 6.5m reso-lution, 80 km swath and 5 spectral bands imager wasdesigned[23].After some years of dealing with the challenging

goal to get a primary private financing of the systemin place, a loan agreement between RapidEye AG,Munich and an international banking consortium,backed by a guarantee of the German Government andthe State of Brandenburg, was signed in June 2003.MacDonald Dettwiler, Richmond, British Columbia(MDA), will be the general contractor—and an ad-ditional investor—for the system. Surrey SatelliteTechnology Inc., Guildford, UK, will be the subcon-tractor for the satellites while Jena Optronik GmbH,Jena, Germany, will supply the cameras (Fig.6). Thesystem is planned to be deployed in the 2007/2008timeframe.Though not addressing the VHR market, the near

daily revisit capability and the commercial businessapproach, which includes also North America as aprime market, makes RapidEye an interesting systemin the context of this paper. Also because the so farleading land/vegetation mapping systems in the midto high resolution domain, i.e. Landsat and SPOT, arein question to be continued over the next years. How-ever, services such as GMES are in demand for thiskind of data.

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6. The ESA sentinel satellite space and groundsystem

The ENVISAT satellite is the flagship of the fleetof ESA earth observation satellites, targeted to op-erational and sustainable services. Starting with theC-Band SAR observations with ERS-1 in 1991, fol-lowed by ERS-2 in 1995, ESA launched ENVISATin 2002. It delivers, multi-functional C-Band SAR(ASAR), medium resolution superspectral optical data(MERIS) and other information, such as by a suiteof atmospheric sounders. However, already during theconstruction of ENVISAT, it became clear to ESA andits member states that putting all these sensors on onesingle and expensive satellite could not be a way tooperate in the future. But up to 2003, no real follow-onsatellite was envisaged to continue the service underthe ESA logo.The go ahead for the GMES implementation plan by

the European Commission and ESA, backed by the re-quirements analysis of primarily the ESA GMES Ser-vice Elements, changed this situation. By early 2004ESA suggested to define, launch and operate a fleet ofsatellites, specifically addressing the European GMESneeds. These “Sentinels” are currently under discus-sion and comprise:Sentinel1: A SAR family, providing continuity

to established applications and to interferometry inparticular.Sentinel2: A superspectral imaging family for ter-

restrial applications providing continuity to Landsatand SPOT-type measurements (including vegetation).Sentinel3: An ocean monitoring family, embark-

ing a wide swath multispectral sensor as well as analtimeter.Sentinel4: A geostationary family for atmospheric

composition monitoring and transboundary pollutiondetection.Sentinel5: An atmospheric composition monitoring

family in low earth orbit.Though the numbering should not indicate a specific

order, it is argued that the SAR-Sentinel, planned to belaunched as early as 2007/08, has a priority to continuewith the C-Band observations of ESA satellites so far.Applications of SAR with proven commercial benefit,such as differential interferometry and ocean services[18], have demonstrated the need to have access tolong term time series and historical archives of the

same sensor data. Deliberately, the sentinels would notdeliver information in the VHR domain. This is leftto the European private and national contributions toGMES.In a parallel effort, ESA has approached the com-

plexity of the earth observation ground segment es-pecially of those technical systems inherited from amission-specific design. In a programme aiming foran Open and Operational (or O2 for short, hence pro-gramme name OXYGEN), ESA and the national ESAfacilities start to address the needs of the future sys-tems and the demands on information products byGMES[21].Priority is given to the interoperability especially of

those systems supporting the users (catalog, archive,etc.) and the multi-mission character of the basicground segment systems. The interoperability shallalso cover the exchange of data and information withnon-ESA systems, such as with national missions andthe meteorological community and with non-spacedata (Fig.7).The precise design of and interfaces to the GMES

services are still under discussion. Here, the interestsand capabilities of the—partly commercial—serviceoperators, non-space data players (see INSPIRE in thenext chapter) and international cooperation (see GEOin the next chapter) need to be considered. Though,it seems to be a consensus that all critical systemsshall be based on open, non-proprietary standards andshall not depend on one single entity or contractor.Room shall be given to introduce innovative ideas andservices especially in the commercial domain.

7. The harmonisation of space and ground data

Operational GMES geo-information services willbe based on the fusion of earth observation data withground based GIS information. Independently fromspace based data, cartographic information as suchform a valuable asset for governments and companies.Unfortunately, different formats and national legisla-tion in Europe so far prevented using spatial infor-mation to a larger extent. The European Commissionand relevant national bodies therefore launched theINSPIRE (Infrastructure for SPatial InfoRmation inEurope) initiative, which works towards the following

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Comm. PublicPublic Public Public ScienceScience Comm.

Access

Non-Europeanagenciesground

segments

GEOSS Access

M &

C

Acquisition

ES

A

Archive

Production

Tasking/Dissem

Satel lite/ M issions

otherEuropeanMissionground

segment

Na t

EO Data Access IntegrationLayer

EU

ME

TS

AT

In-s ituNon-space

systems

Access

Service Infrastructure and Support

GMES Services

Fig. 7. Sketch of a future European Ground Segment Architecture; from ESA’s Earth Observation Task Force document.

principles:

• Data should be collected once and maintained atthe level where this can be done most effectively.

• It should be possible to combine seamless spatialinformation from different sources across Europeand share it between many users and application.

• It should be possible for information collected atone level to be shared between all the different lev-els, detailed for detailed investigations, general forstrategic purposes.

• Geographic information needed for good gover-nance at all levels should be abundant under con-ditions that do not refrain its extensive use.

• It should be easy to discover which geographic in-formation is available, fits the needs for a particularuse and under which conditions it can be acquiredand used.

• Geographic data should become easy to understandand interpret because it can be visualised withinthe appropriate context selected in a user-friendlyway.

In July 2004, the European Commission issued a pro-posal for an INSPIRE implementation directive[19].Under that new directive, spatial information shall be

exploited by the implementation of services aimed atrendering the spatial data more accessible and inter-operable and by dealing with obstacles to the use ofspatial data. The directive requires the EU memberstates to create—amongst others—interoperable meta-data catalogs and data exchange formats under na-tional legislation. Data shall be shared “taking appro-priate measures to prevent distortion of competition”,e.g. with commercial activities. The Commission shallestablish and operate a Community geo-portal. Spe-cific GIS information is named in the Annexes of thedirective. “Elevation” (including such derived fromspace borne measurements) and “georeferenced imagedata of the Earth’s surface, from either satellite or air-borne sensors” is mentioned in theAnnex II. INSPIREwill therefore regulate the data and information man-agement part of the GMES.

8. The global context

Earth observation programmes are also an impor-tant driver for space hardware and application drivenbusiness beyond the European scenario. In the interna-tional context, groups such as the space agency group

532 G. Schreier, S. Dech / Acta Astronautica 57 (2005) 520–533

CEOS, was initiated to find communalities and gaps innational missions. Since 2003, the Earth ObservationSummit, at its first meeting in Washington DC, USAon July 31, 2003, adopted a declaration that signifiespolitical commitment to move toward development ofa comprehensive, coordinated and sustained Earth ob-servation system. The summit participants launchedthe intergovernmental ad hoc Group on Earth Obser-vation (GEO) to adopt a 10 year implementation plan[17]. The plan shall take into account existing activitiesand built on existing systems and initiatives. In sev-eral political meetings, GEO concluded that this willresult in fact not in one single system but in a “GlobalEarth Observation System of Systems” (GEOSS). Thefinal version of the plan will be available and adoptedat the 3rd Earth Observation Summit, to be held inBrussels, Belgium, early in 2005.The European Commission and its member states,

stated that the most significant initiative in Europe tocontribute to GEOSS is GMES and the fleet of satel-lites and interlinked data and information systems. Sofar, GEOSS is more addressing the global environ-mental needs. Critical areas, such as commercial datapolicy or interfacing with private operators have beendeliberately omitted from the plans. Instead, the planforesees to build capacity in the use of earth observa-tion information especially by supporting of and work-ing with developing countries.Meanwhile, European VHR satellite system opera-

tors are establishing a global network of science usersand commercial partners. For example for TerraSAR-X, scientists all over the world will be asked to respondto a science “announcement of opportunity”, sched-uled for release in 2005. In parallel, InfoTerra GmbH,Germany is in negotiation with several internationalcustomers for a direct data reception in their respectivecountries. Experiences with marketing partners suchas SPOT Image contribute to the globalisation of suchnational missions.The next few years will show, to which extent the

European VHR systems will generate enough com-mercial revenue in order to operate the existing andfollow-on satellites. The experience from the privateoperators in the United States shows, that an interna-tional business can only contribute a part of such rev-enue. Of importance for the sustainability of EuropeanVHR satellite systems will be the continuing demandand subsequent purchase agreements from European

programmes such as GMES and initiatives on Euro-pean security.

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[18] Maxwave: project supported by the 5th FrameworkProgramme, project home page:http://w3g.gkss.de/projects/maxwave/.

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[19] European Commission; proposal for a directive of theEuropean Parliament and the Council establishing aninfrastructure for spatial information in the Community(INSPIRE), COM(2004)516 final, Brussels, July 23rd, 2004.

[20] ESA SP-1271, Convention for the establishment of aEuropean Space Agency & ESA Council, Paris, March2003.

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