Precise orbit determination and accuracy analysis of HY-2A satellite using DORIS Doppler data

Abstract

HY-2A is the first ocean dynamic environment monitoring satellite of China, and its precise radial orbit is a critical factor to its scientific research application, for example, its orbit can serve as a reference frame for altimeter measurement. In order to realize precise orbit determination, HY-2A is equipped with Doppler orbitography and radiopositioning integrated by satellite (DORIS), retro-reflector array for the satellite laser ranging (SLR) and global positioning system tracking systems. In this study, DORIS Doppler data is used for its good reputation for precise orbit positioning. We described the strategy of orbit determination using dynamic models in detail, and particularly analyzed the relationship between arc length, orbital determination accuracy, and consumed time, and then concluded that 3-day is the optimal arc length. We carried out detail accuracy assessments of external orbit comparison, overlap orbit validation and SLR range validation. Experimental results show that the radial accuracy can reach 0.0154 m for the 3-day arc, and the radial overlap validation accuracy is better than 0.0223 m, and the accuracy of SLR range validation is better than 0.0964 m. Results demonstrate that the DORIS system meets the orbit precision specifications of HY-2A satellite. Difference between computed orbit and the SSALTO orbit in the radial, along track, and cross track directions from 00:00:25 on September 8 to 00:00:25 on September11, 2012 using DORIS Doppler data.