单星模糊度固定的整数相位钟法及在低轨卫星定轨中的应用

Abstract

单星GPS相位模糊度固定可以显著提升低轨卫星的定轨精度。目前，CNES/CLS、武汉大学和CODE 3家机构都已公开发布用于单星模糊度固定的GPS整数相位钟产品。本文首先利用整数相位钟方法实现单星模糊度固定，并应用于低轨卫星精密定轨中；然后，对比分析了不同机构提供的整数相位钟产品在低轨卫星单星模糊度固定和精密定轨中的应用性能；最后，通过对GRACE-FO编队卫星数据进行处理，发现基于不同机构产品的窄巷模糊度固定成功率都可以达到94%左右。不同机构产品获得的模糊度固定解轨道的SLR（satellite laser ranging）检核残差RMS约为0.9 cm，与模糊度浮点解的定轨结果相比，单星绝对轨道精度提高了约30%。在分别利用CNES/CLS、武汉大学和CODE产品实现单星模糊度固定后，双星相对轨道的KBR（K-band ranging）检核残差RMS分别从5.7、5.4和5.3 mm减小到2.1、2.0和1.5 mm。结果表明，不同整数相位钟产品在GRACE-FO卫星单星模糊度固定和精密定轨中的效果相当。

Alternate abstract:

Fixing single-satellite GPS carrier phase ambiguity could significantly improve the orbit accuracy of low earth orbit (LEO) satellite. Currently, the CNES/CLS,Wuhan University and CODE have published GPS integer phase clock products applied to single-satellite ambiguity fixing. In this paper,the integer phase clock method is used for single-satellite ambiguity fixing, and it is applied to the precise orbit determination of LEO satellite. Then, the application performances of integer phase clock products provided by different agencies in single-satellite ambiguity fixing and LEO satellite orbit determination are compared and analyzed. For GRACE-FO formation satellites, about 94% ambiguities could be fixed based on different products provided by the three agencies.Orbit solutions generated using the products from the three agencies can achieve an RMS of around 0.9 cm checked by satellite laser ranging data.Compared with ambiguity-float orbit solutions, the accuracy of absolute orbit determination with single-satellite ambiguity fixing is improved by about 30%.After fixing single-satellite ambiguities using the different products provided by CNES/CLS, WHU and CODE, respectively, the RMS of K-band ranging validation residuals for relative orbit solutions are reduced from 5.7、 5.4 and 5.3 mm to 2.1、 2.0 and 1.5 mm, respectively. The results show that the integer phase clock products provided by different agencies have similar performances in the single-satellite ambiguity fixing and orbit determination of GRACE-FO satellite.