Tuesday, October 30, 2007

Chinese Space Experts unveil details of “ZY-1” 02B Star

On September 19, "ZY-1"02B Satellite was successfully launched by CZ-4B Rocket from Taiyuan Launch Center. 10 days after, Chinese aeronautics experts show some interested information about the newest sino-brazil remote sensing satellite.

With ZY-1 No. 01 and 02 stars, 02B satellite's most noticeable improvement is a high-resolution CCD imaging camera, which has a 2.37 meter resolution on 778-kilometer high orbit. The image width is 27-km. Although the 2-meter level resolution is only available in black-and-white panchromatic images, it still can be reverted as false-color image under clients' demands.

From the mono-color 2-m resolution satellite image displayed by Chinese experts, people can clearly differentiate automobiles running on the highways, vessels on Yangtze River and airplanes on ground. Chinese experts even told that CRESDA (China Center for Resource Satellite Data and Applications)is going to be follow the lead of "GoogleEarth" to produce a country-scale image database and 3D Simulation map for Internet surfers' browsing.

Beside greatly improved image resolution, "ZY-1"02B satellite also has distinguished upgrade in positioning precision of ground objects. Previous "ZY-1"01 and "ZY-1"02's image has about 5-km warp to real world position and "ZY-1"02 has shrunk this error under 3-km level. But now "ZY-1"02B has technological breakthrough to realize 350-meter level. The main reason is that satellite is installed with a space-borne GPS receiver and star sensor。GPS can strictly locate exact position and orbit of satellite, then satellite star sensor can determine the star's posture to help project the picture on the right geometry position

Obviously, ZY-102B's excellent performance of hi-resolution imaging CCD camera and ground accurate position system bring a fairly meaning strategic value.

In Chinese experts' opinions, China's R&D of civilian remote sensing satellite is equal to France. And from this estimation, it can be extracted that Chinese military imaging satellite, such as recently launched "Yaogan-2" satellite, is about in 0.6-1 meter resolution level and compares with French's Helios 1B imaging satellite.

The production of ZY-102B totally incorporates 16 sub-systems, which are separately taken charge by China and Brazil. Now it has been known that China is responsible for observing device and satellite control, and Brazil for structure design and satellite-borne power system. The agreement of zy-103 and Zy-104 satellites has been affirmative in both countries’ governments. So far ZY-103 star has been assembly a sampler star for thermal control test and electrical measurement in Brazil. INPE (Instituto Nacional de Pesquisas Espaciais) has eagerly expressed its wish of continuous cooperation with China in ZY-1-05 and ZY-1-06 satellites in future.

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