The Center for Earth Observation and Digital Earth (CEODE), Chinese Academy of Sciences (CAS) was formed based on China Remote Sensing Satellite Ground Station, Airborne Remote Sensing Center, and the Laboratory of Digital Earth Sciences, CAS. They have made an important contribution to the development of remote sensing in China, particularly in the promotion of Earth observation technology development and research in the field of Digital Earth. Their development and achievements have laid a solid foundation for the constitution and future development of the CEODE.
(A) The development process of China Remote Sensing Satellite Ground Station
China Remote Sensing Satellite Ground Station (RSGS) was formally established and became operational in December 1986. Mr. Deng Xiaoping personally wrote the name for the institution. The RSGS was the first civilian important infrastructure for receiving and processing multi-resources satellite data, which filled the gap of satellite remote sensing technology in China and opened a new era for China's remote sensing technology and remote sensing applications.
After 20 years’ effort, the infrastructure, operation and maintenance and customer service capabilities in RSGS have made tremendous progress. As a member of the international resource satellite ground station network, it is one of the highest in amount receiving and processing satellite ground stations in the world. The data receiving and distribution amount is ranked among top four in the world and the capacity is in advanced international level. The existing satellite remote sensing data processing system of RSGS can realize the receiving, processing and producing of more than 10 satellites in a high efficiency and high quality manner. It has played a pioneering and demonstrative role in China’s remote sensing satellite ground systems. At present, it has archived over 170 million scenes of earth observing satellite data, and is the center of China's largest earth observation satellite data archives with preservation and accumulation of extremely valuable historical spatial data.
For over 20 years, RSGS has participated in the monitoring and surveying of national land, marine oil pollution monitoring, mineral exploration with remote sensing, national basic surveying and mapping, monitoring and evaluation of forest fires, floods monitoring and evaluation, national environmental monitoring and evaluation, and fishery Monitoring project etc., and has given great support to the survey, evaluation, planning, reasonable use of national land resources, and has provided powerful technical support to national economic construction. It has played a vital role in advancing the development of remote sensing in China, and made an irreplaceable contribution to Chinese remote sensing’s operationalization and industrialization.
In 2007, while actively participating in CEODE’s set-up, various operational and scientific research tasks have been completed as planned. The RSGS received satellite data for a total of 5,143 tracks, with successful receiving rate of about 99.1%. The data processing system has done 11,448 user data products, with an increase of 27.9 percent compared to that in 2006. There were 290,000 scenes of newly added data in archive. All archived data are available through the Internet on a continuous 24hrs basis for on-line indexing and enquiring services. The transmission of quick-look data and achieved data on average of 5.6 channels per day has been made by internet, and an annual rate of 900 scenes products was distributed through the network to users.
In the area of upgrading the system’s running and service capabilities, deep-processing product development study has been made according to the data features of ALOS, TERRA-SAR and other satellite data. This solves the problems of data with shadow, automatic mosaic technology and ortho-rectification technology. RSGS has developed high-resolution automatic image enhancement technology and fast browsing system. The general data recording system，developed by RSGS with independent intellectual property rights has successfully found the solution of the Kashi station in data recording for several satellites of home and abroad, which enable the realization of compatibility with existing operation system and processing flow.
On the construction of 3 RSGS receiving stations located in Miyun of Beijing, Kashi of Xinjiang and Sanya of Hainan provinces, the Kashi station has completed the construction of computer rooms, two antenna bases, housing for electronic power and scientific research, and other ancillary infrastructure. In September 2007, the first set antenna receiving system and its corresponding data recording system was put into trial operation, successfully received SPOT-2 / 4, LANDSAT-5, RADARSAT-1 and other satellite data, and successfully completed the docking experiments of HJ satellite series. In January 28 of 2008, official inauguration of Kashi station was made, marking a complete coverage of satellite remote sensing data in western region of China. At present, the expansion of Miyun station and the construction of Sanya station are being carried out according to plan.
(B) The development process of Airborne Remote Sensing Center
Airborne Remote Sensing Centre of the Chinese Academy of Sciences was setup in May of 1985. In 1986, the center imported two advanced and high performance U.S. Cessna "certificate of merit S / II-type" high-altitude aircraft and began its formal operation. Mr. Hu Yaobang handwrote the title of the Airborne Remote Sensing Center. The remote sensing aircrafts were key scientific equipment for remote sensing sensors independently developed by the Chinese Academy of Sciences for airborne remote sensing information acquisition and processing. Their introduction has greatly improved the technical indicators of China’s airborne remote sensing platform and its operational capacity, and has advanced the development of airborne remote sensing technology, remote sensing sensors, and remote sensing applications. The remote sensing aircrafts are equipped with precise GPS navigation, POS and other systems, and have all weather and days and nights working ability. The airborne platform has realized operation in series and module, on which several remote sensing sensors such as airborne camera, multispectral imager, synthetic aperture radar can be installed. The platform also has functions to collect acid rain and air samples from its hanging cabins.
For over 20 years, the Airborne Remote Sensing Centre has undertaken about one hundred various kinds of airborne remote sensing application projects, and carried out extensive cooperation with other institutions and organizations, and the application areas are increasing. The flight missions have been over 6000 safely, and areas imaged are over 2 million square kilometers, and flight operations have covered 28 provinces, municipalities, and autonomous regions. It has played an important role in meeting national key demands, comprehensive remote sensing experiments, monitoring of severe nature disasters, advancing remote sensing etc. The center has been awarded the Special Prize on Advancement of Science and Technology by the Chinese Academy of Sciences, and the Second Prize on Advancement of Science and Technology by State Council etc. There were 7 flight missions to Qinghai-Tibet Plateau, and under very poor conditions, remote sensing flight missions were conducted for Mountain Everest and Tanggulashan regions, the Yarlung Zangbo River, Lhasa River, Nianchu He basin, the city of Lhasa and other areas. These have provided a large amount of valuable scientific data to the Chinese Academy of Sciences for resources and environment research in Qinghai-Tibet Plateau as well as global change research. The center’s aircraft has conducted remote monitoring flights for eight consecutive years in the areas of the Beijing Olympics, which accumulated a wealth of the region's high-resolution aerial remote sensing data in series for environmental change monitoring. The above data are studied and analyzed for environment, construction, vegetation coverage, traffic and so on for the planned Olympic Games sites and their surrounding areas. The research results are provided to Beijing Olympic Organizing Committee in the form of maps, reports, annual reports and seasonal reports at a regular time, providing scientific basis for the authorities about the planning and construction as well as environment protection of Olympic Games sites and their surrounding areas
In 2007, while the Center for Earth Observation and Digital Earth, CAS was setup, the airborne remote sensing centre completed a total of 10 airborne remote sensing projects as planned. Two remote sensing aircrafts ensured safe operation of 675 hours, and the airborne remote sensing center has completed flight test for synthetic aperture radars developed independently by the Institute of Electronics, CAS, and improved the capacity of self-innovation on SAR technology. The airborne remote sensing center also undertook national basic surveying and mapping projects, and finally completed airborne photogrammetry and demonstration project without control points for the areas of 20,506 square kilometers of Hainan province and 41,298 square kilometers of Chaoyang District of Liaoning province, by using on-board GPS and attitude measurement system (POS), high-resolution airborne photogrammetric images were acquired for the whole imaging areas.
(C) The development process in the field of Digital Earth
Digital Earth is a highly comprehensive integration of space information technology, computer network communication technology, artificial intelligence technology and Earth Sciences, opened a new path for human understanding of Earth, which opens a new way to understand the Earth by our human being.
The development of Digital Earth has been paid great attentions by the Chinese government, relevant fields in Science and Technology as well as in enterprise communities etc. In 1999, the Chinese Academy of Sciences in collaboration with other 19 ministries and international organizations organized the First International Symposium on Digital Earth. At that symposium, “Beijing Declaration on Digital Earth” was passed, which called for holding such an International Symposium biennially on a rotate basis in the world. After that, the Second, Third, Fourth, and Fifth International Symposium of Digital Earth was held in Canada, the Czech Republic, Japan and the United States in 2001, 2003, 2005, 2007 respectively. In 2006, the "Digital Earth Summit" was held in New Zealand, and in 2008 the summit will be convened in Germany again. In 2000, the International Steering Committee for International Symposium on Digital Earth was set up, with Prof. Lu Yongxiang, the President of the Chinese Academy of Sciences as the chairman of the committee. In 2006, the International Society for Digital Earth was established with headquarters in Beijing. Scientists from 16 countries and four international organizations became the members of the first executive committee of ISDE. "International Journal of Digital Earth (IJDE)" founded by the ISDE has been issued globally in March of 2008.
Since its establishment in 2000, Digital Earth Laboratory as a research unit on Digital Earth of the Chinese Academy of Sciences has conducted research on Digital Earth with projects “Basic Theoretical Research on Digital Earth” as well as “Digital Earth Prototype System (DEPS)”, and supported the development of above activities. On the basis of describing the basic theories of Digital Earth, the DEPS has many technical functions such as data reception, complex computing, virtual reality, network services, data mining etc., and demonstrated its application abilities at global, national, and regional different levels, and provided serves to the development and application of Digital Earth at home and abroad. This system has played an important role in the Information Commanding Simulation System of "The 16th National Congress of The Communist Party of China" and "The 17th National Congress of The Communist Party of China ", and was praised by the related leaders of the government and the Office of the Ministry of Public Security. Cooperation’s will on related fields such as digital archaeology, digital tourism, digital ocean etc has been proposed by State Bureau of cultural heritage, the national tourism sectors, and marine research institutions; Cooperation on Digital Cities and Digital Districts have been proposed by Beijing government, Zhongguancun CMC, the Government of Shanghai's Pudong District, and Shenzhen City. An international expert group evaluated the DEPS as "the Digital Earth prototype system plays a leading role in global Digital Earth field, and it has made a landmark contribution in the field of the Science and Engineering internationally in particular, information technology and space applications"