[Commentary] On August 20th, the National Space Administration held the in-orbit delivery ceremony of the Gaofen-7 satellite, and China's high-resolution earth observation system Gaofen-7 satellite was officially put into use.

  [Commentary] According to reports, the Gaofen-7 satellite was successfully launched on November 3, 2019. The satellite is equipped with a dual-line array stereo camera, a laser altimeter and other payloads, breaking through the sub-meter stereo mapping camera technology, and can obtain High spatial resolution optical stereo observation data and high-precision laser altimetry data have greatly improved the level of Chinese satellite earth observation and stereo surveying and mapping.

  [Concurrent] Xing Jin, Director of Data Application Department, Earth Observation and Data Center, National Space Administration

  Gaoqi (Gaofen-7 satellite) is a new system of three-dimensional surveying and mapping satellites. Its two-line array + laser altimetry (system) is currently a unique satellite surveying and mapping technology in the world, and it is the first to realize satellite 1 : 10000 stereo surveying and mapping. Three-dimensional surveying and mapping is just one transit, it can easily obtain three-dimensional landforms. Generally, satellite transit only obtains two-dimensional, and three-dimensional means that the entire elevation can be obtained, with higher accuracy, achieving a breakthrough from plane to three-dimensional.

  [Explanation] As China’s first civil sub-meter optical transmission type 3D surveying and mapping satellite, the use of the Gaofen-7 satellite marks the creation of a space-based, high-time resolution, and high-precision observation of space-based ground-to-earth satellites. The initial formation of observation capabilities can provide strong support for basic surveying and mapping, monitoring and evaluation of urban and rural construction, and agricultural survey statistics.

  [Concurrent] Yang Liuzhong, Researcher, Remote Sensing Application Center, Ministry of Housing and Urban-Rural Development

  In the orbit test of the Gaofen-7 satellite, we mainly carried out the survey of the height of urban buildings, the analysis of the urban green space structure, the survey of urban three-dimensional transportation facilities, and the monitoring of the protection of historical and cultural blocks. This satellite can provide rapid and large-scale modeling and surveys of cities, and has a very good effect on feature recognition and area and height measurement.

  [Concurrent] Tang Xinming, Chief Engineer, Land Satellite Remote Sensing Application Center, Ministry of Natural Resources

  Because Gaofen-7 (satellite) is characterized by three-dimensional, it can obtain elevation. The original resource surveys or farmland surveys we did were mostly done on a plane, and we didn't have much control over the slope of this farmland. Then after the Gaofen-7 (satellite), it can be used for the survey of sloping farmland, the survey of mountains and rivers, forests, fields, lakes and grass resources, and related monitoring can be carried out later.

  [Explanation] At the delivery ceremony, China National Space Administration Director Zhang Kejian said that the Gaofen-7 satellite can not only meet the relevant data needs of Chinese domestic users, but also provide strong spatial information support for countries along the "Belt and Road". It is of great significance to serve economic and social development and increase China's aerospace international influence.

  [Concurrent] Zhang Kejian, Director of the National Space Administration

  It is necessary to cultivate the core brand of "China High Score" international cooperation and enhance China's aerospace international influence. In the follow-up, we will further serve the overall political and diplomatic situation of the country, and accelerate the promotion of high-scoring data abroad and into the world. It is necessary to strengthen the high score platform international data exchange and sharing, and core capacity building such as international product production services, and provide data application services for the "Belt and Road" spatial information corridor data center.

  Cheng Yu Guo Chaokai reports from Beijing

Editor in charge: [Li Yuxin]