基于CAS和DLR产品的卫星DCB特性分析

Characteristic Analysis of Satellite DCB Products Provided by CAS and DLR

差分码偏差(differential code bias,DCB)在GNSS时空信息的生成及其传递过程中具有关键作用,DCB参数的特性分析对于促进GNSS高精度导航定位及授时应用具有重要意义。基于中国科学院(Chinese Academy of Sciences,CAS)和德国宇航中心(German Aerospace Center,DLR)发布的DCB产品,对GPS卫星频内偏差(intra-frequency bias)、频间偏差(inter-frequency bias)以及BDS卫星频间偏差平均月稳定度进行了分析,研究了不同电离层处理策略对频间偏差周期特征的影响。结果表明,两家分析中心提供的GPS卫星频内偏差的平均月稳定度小于0.07 ns,GPS卫星和BDS卫星频间偏差的平均月稳定度分别小于0.08 ns和1.12 ns,GPS卫星频间偏差的稳定度优于BDS卫星;部分GPS卫星C1C-C2W频间偏差存在周年或半周年的周期变化,且两家DCB产品的周期没有因解算方法不同存在差异。

Differential code bias(DCB)plays a key role in the generation and transmission of GNSS space-time information,and the characteristic analysis of DCB parameters is of great significance for promoting GNSS high-precision navigation positioning and timing application.Based on DCB products provided by Chinese Academy of Sciences(CAS)and German Aerospace Center(DLR),the average monthly stabilities of the GPS satellite intrafrequency bias,the GPS satellite inter-frequency bias and BDS satellite inter-frequency bias is analyzed,and the influence of different ionospheric processing strategies on the periodic characteristics of the inter-frequency bias is studied.The results show that the average monthly stabilities of GPS satellite intra-frequency bias products provided by the two analysis centers are less than 0.07 ns,the average monthly stabilities of GPS satellite and BDS satellite inter-frequency bias are less than 0.08 ns and 1.12 ns.The stability of GPS satellite inter-frequency bias is better than that of BDS satellite.Some satellites’DCB(C1C-C2W)have annual and half annual periods,and the periods of the DCB(C1C-C2W)provided by CAS and DLR do not differ.