共查询到15条相似文献,搜索用时 62 毫秒
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针对StarFire星站差分GPS系统静态观测定位结果存在收敛和发散现象,提出了直接平均法、平均中位法和密度中位法以获取其精密静态解。平均中位法考虑了收敛和发散过程,其计算结果要优于直接平均法;但由于没有相应的收敛点和观测点定位模型,平均中位法获取的精密静态解存在一定的不确定性;基于观测值密度分布的密度中位法不需要确定收敛点和发散点,就能得到精密静态解。实例表明,当观测环境相对稳定,观测过程没有明显的收敛和发散现象时,直接平均法、平均中位法和密度中位法的精密静态解基本相同,密度中位法略优;当观测环境差,观测过程出现明显收敛和发散现象时,密度中位法最优,平均中位法次之。 相似文献
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合理的观测值权阵能提高BDS、GPS及其组合系统伪距单点定位的精度。对比分析了各系统在实测数据和模拟观测条件下等权模型、高度角模型、Helmert方差分量模型3种随机模型的定位精度。结果表明:在模拟观测条件下, BDS/GPS组合系统精度最高,BDS系统次之,基于Helmert方差分量模型的精度最优,高度角模型次之;在正常观测条件下, BDS系统平面精度高于GPS系统,但高程精度低于GPS系统,其余结论与模拟条件下结果一致。研究结果可在提高BDS、GPS及其组合系统伪距单点定位精度方法中起参考作用。 相似文献
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Aaron M. Thode Peter Gerstoft William C. Burgess Karim G. Sabra Melania Guerra M. Dale Stokes Michael Noad Douglas H. Cato 《Oceanic Engineering, IEEE Journal of》2006,31(3):696-710
A portable matched-field processing (MFP) system for tracking marine mammals is presented, constructed by attaching a set of autonomous flash-memory acoustic recorders to a rope to form a four-element vertical array, or "insta-array." The acoustic data are initially time-synchronized by performing a matched-field global inversion using acoustic data from an opportunistic source, and then by exploiting the spatial coherence of the ocean ambient noise background to measure and correct for the relative clock drift between the autonomous recorders. The technique is illustrated by using humpback whale song collected off the eastern Australian coast to synchronize the array, which is then used to track the dive profile of the whale using MFP methods. The ability to deploy autonomous instruments into arbitrary "insta-array" geometries with conventional fishing gear may permit nonintrusive array measurements in regions currently too isolated, expensive, or environmentally hostile for standard acoustic equipment 相似文献