不同对流层模型对机载精密单点定位的影响分析

Influence analysis of different tropospheric models on airborne precise point positioning

  • 摘要: 对流层延迟是影响精密单点定位(PPP)性能的主要因素之一,尤其是高程方向的解算精度,一般采用模型改正结合参数估计的方法进行处理. 而高程方向位置解算精度对航空重力测量中的重力场恢复至关重要. 因此,分别采用GMF、NMF、VMF1、VMF3作为映射函数,并分别选取4\;\mathrmm\mathrmm/\sqrt\mathrmh10\;\mathrmm\mathrmm/\sqrt\mathrmh50\;\mathrmm\mathrmm/\sqrt\mathrmh100\;\mathrmm\mathrmm/\sqrt\mathrmh作为随机游走噪声参数,对比分析不同对流层模型对机载数据的PPP的影响. 实验结果表明:不同对流层模型对北(N)、天顶(U)方向定位结果影响较大,模型差异可达到3~4 mm;VMF1和VMF3模型在定位精度上优于GMF和NMF模型;选取4\;\mathrmm\mathrmm/\sqrt\mathrmh作为随机游走噪声(RWN),较其他三种定位精度更高.

     

    Abstract: Tropospheric delay is one of the main factors that affect the performance of precise point positioning (PPP), especially the accuracy of elevation direction solution. Generally, model correction and parameter estimation are used to deal with it. The accuracy of elevation direction solution is very important for gravity field recovery in airborne gravimetry. Therefore, GMF, NMF, VMF1 and VMF3 are respectively used as mapping functions, and 4 \rmm\rmm/\sqrt\rmh, 10 \rmm\rmm/\sqrt\rmh, 50 \rmm\rmm/\sqrt\rmh and 100 \rmm\rmm/\sqrt\rmh are respectively selected as random walk noise parameters to compare and analyze the influence of different tropospheric models on precise point positioning of airborne large dynamic data. The experimental results show that different tropospheric models have great influence on the positioning results in north (N) and up (U) directions, and the model difference can reach 3 mm to 4 mm; VMF1 and VMF3 models are superior to GMF and NMF models in positioning accuracy; selecting 4\;\rmm\rmm/\sqrt\rmh as random walk noise has higher positioning accuracy than the other three models.

     

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