| 摘要: |
| 为了提高实时卫星钟差估计的精度和稳定性，提出了一种顾及轨道误差的实时GPS钟差估计方法。基于超快速轨道产品，分析了轨道标准差与绝对轨道误差的相关性。通过线性插值获得实时轨道误差信息，以优化先验残差的随机模型。基于先验轨道标准差阈值，采用分段方式剔除实时轨道异常卫星对应的观测值。实验结果表明：轨道标准差和轨道误差的相关性高达0.82。与常用的高度角相关的随机模型相比，GPS卫星钟差估计精度最大提高了15.2%，平均提高了8.1%，钟差误差的时间序列更加平稳，所有GPS卫星的平均钟差STD均在0.15ns以内。因此，超快速轨道产品中提供的轨道标准差与绝对轨道误差表现出较强相关。采用顾及轨道误差的实时钟差估计方法可提高GPS卫星钟差估计精度，准确识别并剔除GPS实时轨道异常的卫星，从而提高GPS实时钟差估计的稳定性。 |
| 关键词: 随机模型 轨道误差 实时卫星钟差估计 GPS |
| DOI： |
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| 基金项目:国家自然科学基金 (41731066)；国家重点研发计(2018YFC1505105) |
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| A Real-Time GPS Clock Estimation Method Considering Orbital Error |
| TAN Yue,HUANG Guanwen,FU Wenju,WANG Le,XIE Wei,CAO Yu |
| (College of Geological Engineering and Geomatics, Chang'an University, Xi'an 710054, China;State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China) |
| Abstract: |
| In order to improve the accuracy and stability of real-time clock offset estimation, a real-time GPS clock estimation method considering the orbital error is proposed. Based on the ultra-rapid orbit products, the correlation between the orbital standard deviation and the absolute orbital error is analyzed. The orbital error information is obtained by linear interpolation to optimize the stochastic model of prior residuals. Based on the prior orbital standard deviation threshold, the observation values corresponding to satellites with anomaly real-time orbit are eliminated by piecewise method. The experimental results show that the correlation between the orbit standard deviation and the orbit error is up to 0.82. Compared with the commonly used elevation dependent stochastic model， the maximum accuracy of GPS satellites clock offset estimation is increased by 15.2%, and the average accuracy is increased by 8.1%. The time series of clock offset error are stabler, and the average clock offset STD of all GPS satellites is within 0.15ns. Therefore, the orbital standard deviation provided in the ultra-rapid orbit products is strongly correlated with the absolute orbital error. GPS satellites clock offset estimation can be improved with the clock estimation method considering the orbital error. The anomaly GPS real-time orbit satellites can be identified and eliminated accurately to improve the stability of GPS real-time clock offset estimation. |
| Key words: Stochastic model Orbital error Real-time satellite clock offset estimation GPS |
