The Precise Orbit Determination for HY2A Satellite Using GPS,DORIS and SLR Data

The problem of precise orbit determination was studied using three kinds of HY2Aobserva-tional data of GPS,DORIS and SLR separately and together in February 2013.Comparing the derivedorbits with CNES precise orbits,the results show:(1)Using GPS,DORIS and SLR data separately,the GPS data to determine the radial orbit of average accuracy was 1.3cm,the three-dimensional posi-tion was about 6.2cm;the radial average accuracy of the DORIS solution was 1.6cm,and slightlyworse than the results of GPS;and SLR to determine the radial orbit of the average accuracy was 2.3cm.(2)Comparing the CNES orbits with the orbits derived from GPS,DORIS and SLR data togeth-er,the difference of RMS was 1.2cm in the radial direction,and the three-dimensional position was6.5cm.Compared to GPS solution,the combined three kinds of data cannot improve the accuracy ofthe derived orbit,but it is helpful to keep the calculated orbit in relative stability.(3)Using SLR datawith high elevation passes(above 60degrees)to validate the accuracy of the GPS/DORIS orbit,wefound the RMS of the estimated biases to be about 2.5cm,showing that HY2Adata can determinethe centimeter-level orbit.