龚学文, 王甫红. 一种适用于星载GPS自主定轨的地球引力近似计算改进方法[J]. 武汉大学学报 ( 信息科学版), 2019, 44(3): 371-377. DOI: 10.13203/j.whugis20160498
引用本文: 龚学文, 王甫红. 一种适用于星载GPS自主定轨的地球引力近似计算改进方法[J]. 武汉大学学报 ( 信息科学版), 2019, 44(3): 371-377. DOI: 10.13203/j.whugis20160498
GONG Xuewen, WANG Fuhong. An Improved Approximate Calculation Method of Earth Gravity Suitable for Space-Borne GPS Real-Time Onboard Orbit Determination[J]. Geomatics and Information Science of Wuhan University, 2019, 44(3): 371-377. DOI: 10.13203/j.whugis20160498
Citation: GONG Xuewen, WANG Fuhong. An Improved Approximate Calculation Method of Earth Gravity Suitable for Space-Borne GPS Real-Time Onboard Orbit Determination[J]. Geomatics and Information Science of Wuhan University, 2019, 44(3): 371-377. DOI: 10.13203/j.whugis20160498

一种适用于星载GPS自主定轨的地球引力近似计算改进方法

An Improved Approximate Calculation Method of Earth Gravity Suitable for Space-Borne GPS Real-Time Onboard Orbit Determination

  • 摘要: 提出了一种适用于星载GPS自主定轨的改进的地球引力近似函数方法(improved gravity acceleration approximation function,IGAAF)。对IGAAF方法的性能进行评估,结果表明:IGAAF方法的计算耗时小于45×45阶球谐模型;拟合系数容量仅为200~320 kB;引力加速度的截断误差(3D RMS)处于1×102~1×103 nm/s2量级,小于每颗低轨卫星自主定轨所需的最优阶次球谐模型(GOCE:105×105,CHAMP:85×85,GRACE-A:65×65,ZY3/TerraSAR-X:55×55);将IGAAF方法应用于星载GPS自主定轨试验,相比于球谐模型,不会降低自主定轨精度。IGAAF方法在保证定轨精度的同时兼顾计算效率与系数容量的平衡,在星载GPS自主定轨的工程化应用中具有较强的实用价值。

     

    Abstract: We present an improved gravity acceleration approximation function (IGAAF) suitable for space-borne GPS real-time onboard orbit determination. The test of analyzing IGAAF's performances demonstrates that IGAAF maintains the truncation error in the magnitude of 1×102-1×103 nm/s2 only with the computational burden less than a 45×45 spherical model and a 200-320 kB RAM requirement for fitting coefficients, and that its accuracy is slightly superior to the spherical models with optimal degree and order for autonomous orbit determination (105×105 model for GOCE, 85×85 for CHAMP, 65×65 for GRACE-A and 55×55 for ZY3 and TerraSAR-X). Compared to the spherical model, IGAAF does not decrease the orbit accuracies. The IGAAF method attains a good trade-off between computational efficiency and coefficient capacity without decreasing the orbit accuracy, so it is of strong engineering value for space-borne GPS autonomous orbit determination.

     

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