Tuesday, October 21, 2008

HJ-1A and HJ-1B Chinese satellites for Environmental Monitoring

Successful on-orbit tests of the two new mini satellites for environmental monitoring and emergency prediction are under way in China.

Two mini satellites 500 kg each were launched on September 6 from Taiyuan launch site (Shanxi province) carried by the “Long March -2С” launch vehicle. The satellites registered as HJ-1A and HJ-1B (Huan Jing – “Environment”) were successfully placed on sun-synchronous orbits at the altitude of 650 km. Estimated life of each spacecraft is 3 years.

For the first time in the history of Chinese space industry the satellites were placed on orbit that were specially designed for the purposes of real-time imagery of emergency areas, monitoring of environmental condition and prediction of emergencies. Development of emergency monitoring satellite system started in 2000 pursuant to the project of State Environment Protection Agency and National Committee for Protection from Emergencies by means of the Aerospace Corporation of China.

The system was named «4+4» since it would consist of 4 satellites equipped with radars, which would allow receiving images of any place on the Earth on a daily basis. The first stage system called «2+1» consists of two already launched optical satellites HJ-1A/B and the radar satellite HJ-1C, which will be placed on orbit in 2009.

Both mini satellites HJ-1A and HJ-1B are fitted with standard optical scanner systems for imagery with 30 meter spatial resolution and 720 km swath in four spectral zones (3 channels in visible spectral zones and 1 - in near infrared zone). In addition, for the first time in Chinese practice the HJ-1A satellite is equipped with hyperspectral optical camera, which allows receiving images in 115 narrow zones of visible and near infrared spectral regions (width - 5nm, band - 0.45-0.95 µm) with 100m spatial resolution in 50km swath.

The HJ-1В mini satellite is also equipped with an optical scanner for performing imagery in four bands of infrared spectrum (near - 0.75-1.1µm, short-wave - 1.55-1.75 µm, medium-wave - 3.5-3.9 µm and thermal - 10.5-12.5 µm) with 150 м and 300 м (thermal channel) spatial resolution in 720km swath. Infrared band imaging hardware allows day and night determination of fire seats characteristics, detection of increased tectonic activity zones and offshore areas of pollution.

The satellites hardware was activated and the ground control stations received first high quality images. Satellite emergency monitoring system will for the first time ever be operated by specialized agencies – counterparts of Russian Ministry of Emergency Situations and Ministry of Natural Resources. This will allow expediting the process of finding solutions to the issues of satellite control and targeted application of space data.

Member of the Political Bureau of the Central Committee of the Communist Party of China, Vice-Prime Minister of the State Council of the People’s Republic of China and Chairman of the State Committee for Mitigating Damages from Emergencies, Hui Liangyu extended his congratulations to engineers, scientists and test operators with the successful launch of the two environmental monitoring satellites.

In his greeting Hui Liangyu pointed out that in 2008 China was stricken with large-scale natural disasters. Thus, in spring the regions to the south from the Yangtze River suffered from snowfalls and low temperatures, which developed in the emergency, then the disastrous earthquake stroke Sichuan province (South-West China).

These emergencies lead to immense human and material losses. The launch of the satellites provides opportunity to improve the emergency monitoring system and will play an important role in environmental protection.



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