The Dragon Programme– ESA and China Cooperate in

Earth Observation

High-resolution satellite image of the Beijing area taken with Envisat’s MERIS instrument

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Dragon Programme

ESA has been cooperating with China’s National RemoteSensing Centre (NRSCC) in the development of EarthObservation (EO) applications for the last 10 years.

Following recent high-level meetings between Chinese andESA officials, it was decided to reinforce this cooperation,which has now been given new momentum with the creationof a dedicated three-year EO exploitation programme called‘Dragon’. This programme forcuses on the development of EOscience and applications in China using data primarily fromESA’s ERS and Envisat missions.

IntroductionAs China has a land surface of more than 9.6 millionsquare kilometres, satellite-based Earth observation isclearly an ideal tool for the monitoring and overallmanagement of the country’s resources. Anotherimportant factor is that today China accounts for one-fifth of the World’s population, with 1.45 billioninhabitants, and is also currently the World’s fastestgrowing economy. With this rapid growth and the stressthat it implies on the country’s natural resources and itsenvironment, remote sensing can provide precise datato help decision-makers at all levels.

Satellite data can be used in land-resource mappingapplications such as forest inventory and management,rice-production monitoring, and water-resourceassessment and management. A new element in theDragon programme is the extension of techniques andmethods for monitoring oceans and atmosphere as well

Yves-Louis DesnosScience and Applications Department, ESA Directorate of EarthObservation, ESRIN, Frascati, Italy

Karl BergquistInternational Affairs, ESA, Paris

Li ZengyuanNational Remote Sensing Centre of China (NRSCC),Ministry of Science and Technology, Beijing

Earth Observation

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as land using the full complement ofEnvisat’s instruments.

Satellite data can also contribute to themitigation of the effects of naturaldisasters by providing timely informationto local and national authorities. Thenatural disasters that affect China are oftenon a gigantic scale and include flooding ofthe Yangtze River, earthquakes on theTibetan plateau, and droughts, which areparticularly acute in China. When suchcalamities occur, Earth Observation can bethe key to understanding and managing theensuing crises. Hopefully, in the nearfuture it will also help us to predict suchevents through the use of assimilationmodels and long time series of historicaldata to establish trends and alert theappropriate authorities when changes inthose trends are first observed.

Early CooperationESA’s first contacts with China in theEarth Observation domain wereestablished when the Chinese authoritiesexpressed an interest in cooperating onERS data applications. China’s remote-sensing ground station in Beijing wassubsequently upgraded to receive ERSdata in 1994 and the two sides signed anAgreement to that effect.

In May 1997, China and ESA decided tobegin a cooperation project for theincreased operational use of ERS data. Inorder to stimulate exploitation of the

Synthetic-Aperture Radar (SAR) datafrom ERS-1 and 2, five pilot projects werecreated, addressing:– Rice Mapping in Southern China– Land-use Mapping for the Beijing Area– Flood Monitoring– an Oceanographic Study, and– Mapping China’s Forests.

The following year, when Chinaexperienced its worst floods of theCentury, ERS radar imagery was used foroperational mapping of the flood events.The Beijing ground station was able toprocess and deliver ERS images to endusers just 24 hours after their acquisition.

This first cooperation was considered sosuccessful by ESA and NRSCC that it ledto discussions on how to consolidate andincrease it in the future. In a meeting withESA’s Director General, China’s Ministerof Science and Technology, Mr XuGuanhua, commented that spaceapplications were recognised in hiscountry as a key tool for the developmentof the Chinese economy and improvedliving conditions for its people.

In the light of the above progress, ESA’sEarth Observation Directorate and theirChinese counterparts at NRSCC began aconsultation process on how to reinforceand improve the cooperation to alsoinclude joint research. The result is ‘TheDragon Programme’, which was officiallylaunched in Xiamen, China in April 2004.

The Dragon Programme

ObjectivesThe Dragon Programme’s main objectiveis to establish joint Sino–European teamsfor the exploitation of data from ESA’sERS and Envisat satellites for science andapplications development. The teams, with lead scientific investigators fromEurope and China, will be addressing the following identified priority themes:Agricultural Monitoring, FloodMonitoring, Forest Mapping, RiceMonitoring, Forest-Fire Monitoring,Oceanography, Terrain Measurement,Seismic Activity, Landslide Monitoring,Air-Quality Monitoring and Forecasting,Chemistry/Climate Change in theAtmosphere, Deriving Forest Informationfrom POLInSAR Data, DroughtMonitoring, Water Resources andHydrology, and Climate and OceanSystems

First achievements Programme preparation began with specialbriefings for European scientists inSeptember 2003 in Rome, and for Chinesescientists in October 2003 in Beijing. Theresponse from both the European andChinese scientists who attended was verypositive. The Dragon Call for Proposalswas then jointly prepared by ESA andNRSCC and issued in November 2003.Some 25 responses were received and

Prof. Jose Achache (left), ESA’s Director of Earth Observation Programmes, and Prof. Zhang Guocheng (right), Deputy Director of China’s NRSCC, giving their opening addresses at the Dragon Symposium inXiamen, People’s Republic of China, on 27 April 2004

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peer-reviewed from the scientific andtechnical feasibility viewpoints, resultingin the final selection of 15 integratedprojects covering the priority themesdefined by ESA and NRSCC.

In order to facilitate the preparations, anESA–NRSCC Dragon web site wasofficially launched in March 2004(http://earth.esa.int/dragon). It carriestechnical documentation on theProgramme and serves both as aninformation and reporting portal. Aprogramme brochure was also preparedand widely distributed in both Europe andChina.

As part of the Dragon Programme,training courses will be organised andexchanges of trainees working within theprojects are also anticipated. This willstrengthen both the cooperation and thetechnical exchanges. The first trainees

from the Chinese Academy of Forestryhave already spent three months at ESRINin preparation for the two projects relatedto forest monitoring using spaceborneSynthetic Aperture Radars (SARs). InOctober this year, a week-long trainingcourse entitled ‘ESA MOST DragonProgramme Advanced Training in OceanRemote Sensing’ will be organised inQingdao, where the three major Chineseoceanographic institutes are located.

The recent Dragon Symposium (27-29April 2004) was organised by ESA andNRSCC and hosted by the local authoritiesof Xiamen. It was attended by 130 scientistsrepresenting more than 60 institutes inEurope and China, and was effectively theformal kick-off for all 15 joint projects. Thejoint teams have now started their work,their data requests have been refined, anddetailed work plans have been established.

Research Areas within the DragonProgramme

The Dragon Programme includes projectsfocusing on monitoring natural landresources, on supporting natural-disastermanagement, and on studying theatmosphere and ocean in China. Thefollowing are just a small selection:

Rice production monitoringThe United Nations has declared 2004 the‘International Year of Rice’. China is theWorld’s largest rice producer, accountingfor 35% of global output. At the same time,harvest areas are declining and demand isforecast to increase by 70% over the next30 years.

The rice-monitoring project will useEnvisat’s Advanced SAR (ASAR)capability to observe rice-growing areasday and night, regardless of cloud cover.This is particularly important becausepersistent cloud cover in China’s rice-growing regions is currently limiting theamount of information that can begathered using optical satellite sensors.The anticipated outcome of the project isto improve rice-monitoring techniquesthrough better yield modelling and regular

Dragon Programme

The ESA–NRSCC Dragon web site http://earth.esa.int/dragon

The Dragon brochure

Participants in the Dragon Symposium

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and accurate rice-field mapping atprovincial level.

At the same time, rice fields producemethane, which is a major greenhouse gas,and both methane distribution andseasonal concentrations can be monitoredand better understood using theSCIAMACHY instrument carried byEnvisat. Improved water management canhelp to reduce methane emissions duringthe crop’s growth cycle. Some areas havetwo to three crop cycles per year and sochanging the water-management regimecould significantly reduce methaneemissions in the rice-growing regions.

Flood mapping and monitoringSevere floods are estimated to have costChina 32 billion US$ in 1998 and 20billion US$ in 2003. Improved floodforecasting and monitoring is thereforevery important for the country. In theDragon project titled ‘Flood Plain DisasterRapid Mapping and Monitoring’, Envisat’sASAR will be used to great advantage,thanks to its all-weather, day-and-nightimaging capability. The project will alsohave a flood-prevention element, byexploiting existing ERS SAR (since 1991)and optical data archives to assess thevulnerability of particular geographicalareas to inundation and reassessingparticular flooding events that haveoccurred over the years.

Rice fields in China imaged with Envisat’s ASAR instrument using alternating polarisations

NOAA AVHRR image of Dongting Lake taken on 7 July 1999. Flooded areas aredisplayed in red

Envisat ASAR image of Dongting Lake and the surrounding area taken in 2003

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For disaster evaluation and recoveryactions, airborne and spaceborne SAR datawill provide such vital information asestimates of flooded areas per region,population numbers affected, arable landinundated, oil wells inundated, extent ofrailway lines submerged, and the locationsand extent of breaches in embankmentsand flood dykes.

The project will benefit from theimpressive rapid-alert system that has beenput in place in China. The response timefrom the taking of the satellite imagery tothe arrival of the relevant information onthe desk of the responsible authority hasbeen improved from a few days to just 5

hours. The model developed in China willalso be tested in Europe with a view tofurther improving response times here too.

For forecasting purposes, EO data willbe used in combination withmeteorological data in the modeling chain.The goal is to be able to provide floodforecasting maps on an hourly basis.

Air-quality monitoringThe ‘Air-Quality Monitoring andForecasting’ project will include thecompilation of historical time series ofatmospheric gas concentrations usingGOME observations (from 1995 to 2003from ERS-2), and the more recent data

from Envisat’s SCIAMACHY instrument(2003 to date). Maps showing the meanannual concentrations and distributions ofnitrogen dioxide in China have alreadybeen made using SCIAMACHY data.When they are compared with population-density maps, it is possible to see thecorrelation between areas with highpopulation densities and those with highconcentrations of atmospheric pollutants.It is due to the burning of fossil fuels andthe byproducts of industrial processes.

Such maps produced from temporalseries of satellite observations areimportant tools for governments, andpolicy makers in assessing trends inatmospheric pollutant concentrations andimplementing the necessary controls. Theeffectiveness of the pollution controlsintroduced can also be evaluated usinglong-time-series data sets.

Red-tide monitoringThe ‘Ocean, Environment and Climate’project is a multi-disciplinary effort aimedat studying ocean waves, currents andcolours, and ocean-bottom topographyusing a combination of SAR and opticalremote sensing.

One element is the monitoring usingMERIS data on ‘red tides’ in the ChinaSeas. These tides occur mainly in coastalareas around the World and can have adevastating impact on the local fishing andshellfish industries. Red tides, which arecaused by dense growths of bacteria andalgae, can even be toxic for humans. Theyare becoming increasingly common inChina (see accompanying table) due to theheavy sewage and industrial pollutionalong the country’s densely populated eastcoast and from the Yangtze River. One ofthe project’s goals, therefore, is to developtechniques and data sets using MERIS datato map the extents and durations of suchtides so that fisheries can be provided withaccurate and up-to-date information.

Dragon Programme

Tropospheric nitrogen-dioxide concentrations over the People’sRepublic of China

A so-called ‘red tide’ photographed from a ship off Fu Ding City,in China’s Fujian Province, on 6 May 2002. This particular redtide covered an area of more than 500 km2

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Future Outlook The Dragon Symposium in Xiamenbrought together top scientists fromEurope and China who are teaming uptogether with clear objectives and workplans to address serious environmentalissues. The excellence of the joint teams,the quality in-situ data available forvalidation, and the timely availability ofEnvisat multi-sensor data sets providesconfidence that the Dragon Programmewill result in innovative developments inthe Earth Observation science andapplications domains. Having beendemonstrated and validated in the Chinacontext, they can also be put to excellentuse in Europe and elsewhere in the World.

The second Dragon Symposium willtake place in Europe in Spring 2005 andwill be the opportunity to review andassess the achievements after the first yearof this joint cooperative programme withthe People’s Republic of China. r

Occurrences of red tides in the China Seas in 2002 and 2003

Times Area (km2)Site 2002 2003 2002 2003

Yellow 3 5 310 410Sea

Bohai 14 12 300 460Sea

EastChina 51 86 9 000 12 990Sea

SouthChina 11 16 540 690Sea

Total 79 119 10 150 14 550

MERIS image showing river-discharge and sediment loading in the East China Sea