Precise orbit determination of Haiyang-2 using satellite laser ranging

With the successful launch and official commissioning of China’s first dynamic ocean environment satellite Haiyang-2 (HY-2), China’s capabilities for oceanic environment monitoring and oceanic resource detecting have been further improved and enhanced. Precise tracking and orbit determination are not only key technical concerns in the ocean dynamic environment satellite project but also necessary conditions for carrying out related oceanic science research using observational data obtained using spaceborne instruments including radar altimeter. In this study, the current available status of international satellite laser ranging (SLR) monitoring on HY-2 was introduced. Six-months of SLR data from HY-2 were processed to obtain precise satellite orbit information using the dynamic orbit determination method. We carried out a detailed assessment of the SLR orbit accuracy by internal evaluation, comparisons with the orbit derived by the French Doppler orbitography and radio-positioning integrated by satellite (DORIS) system, and station-satellite distance validation. These assessments indicate that the three-dimensional orbital accuracy of HY-2 is about 12.5 cm, and the radial accuracy is better than 3 cm. It provides a good example of the application of international SLR monitoring and precise orbit determination in China’s earth observation satellite project.