Image of Yellow River Delta taken by Gaofen-4 Earth observation satellite. (Photo provided by State Administration of Science, Technology and Industry for National Defense)
China released the first batch of photos taken by its most sophisticated Earth observation satellite to date, Gaofen-4 on Wednesday.
The images released by the State Administration of Science, Technology and Industry for National Defense (SASTIND) cover an area of 400 km by 400 km, including 17 photos with ground resolution of 50 meters for the visible light camera and 400 meters for the infrared one. View on released images at http://en.people.cn/n3/2016/0204/c90000-9014004.html.
This photos cover Beijing, the Flaming Mountains in Xinjiang, Namtso in Tibet, Dunhuang in Gansu, Mount Qomolangma, the Yellow and Pearl River deltas, Danjiangkou in Hubei, Xiaolangdi on the Yellow River and parts of Australia . Among them, three images of Beijing are 50-meter multispectral and panchromatic, six of the images of the parts of Australia suffering large fires are 400-meter medium wave infrared images and the other eight are 50-meter multispectral ones.
The satellite was launched on Dec. 29, 2015 and entered a geostationary orbit (GEO) on Jan. 4, 2016. Gaofen-4 has received and dealt with 8.3 terabytes of data, covering 26.2 million square kilometers, including 8.52 million square kilometers in China and 17.69 million square kilometers overseas by Jan. 31, 2016.
GEO satellites constantly stay above a patch of Earth, thus providing constant 24 hour surveillance of a geographic area. By contrast, low earth orbit (LEO) satellites such as the U.S. KH-11 spy satellites are closer to the Earth, so their speed exceeds that of the Earth's rotation (meaning that they cannot maintain continuous surveillance over specific locations). In the Gaofen 4's case, its range of view is a 7,000km by 7,000km box of 49 million square kilometers of Asian land and water in and around China.
The test and evaluation work of the satellite will be finished during mid-March and the end of May this year and then the satellite will be put into formal operation, according to Tong Xudong, chief designer of the Gaofen project at SASTIND.