外测数据对流层折射误差修正及精度分析

Correction of Tropospheric Refraction Error of Tracking Data and Error Analysis

针对对流层引起的航天器外测数据折射误差,基于对流层分段模型,以测站历史气象数据拟合折射衰减系数,建立测控站上空对流层折射率模型,并利用实测地面折射率对统计模型进行优化,进一步提高模型反映大气剖面的真实性。利用该模型对S频段多颗在轨卫星50多跟踪圈次的实测外测数据进行修正分析,并与微波辐射计实时修正结果进行比较,测距、测角、测速互差分别优于0.9m、0.02°、0.06m/s。将该模型应用于卫星长管外测数据的实时修正,可提高轨道测量数据质量。

To measure the refraction error of spacecraft tracking data caused by troposphere,a statistical tropospheric refractive index model for TT＆C stations is established by fitting of refraction attenuation coefficients with historical meteorological data based on tropospheric segmentation model.The statistical index model is further optimized using measured ground refractive index to reflect the atmospheric profiles as accurately as possible.The model is used in correction analysis for more than 50 passes of the tracking data of several in-orbit S-band satellites and the result is compared with that measured by microwave radiometers.It is found that the error of ranging,angular measurement and range rate is smaller than 0.9 m,0.02° and ±0.06 m/s respectively.The proposed model is applied in real-time tracking data error correction in routine satellite operation management to increase the quality of orbit determination data.