Zero-difference GPS ambiguity resolution at CNES-CLS IGS Analysis Center
Zero-difference GPS ambiguity resolution at CNES-CLS IGS Analysis Center
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DOI：
10.1007/s00190-012-0559-2
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Marty, Jean-Charles
中科院分区：
文献类型：
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作者：
Loyer, Sylvain;Perosanz, Felix;Marty, Jean-Charles
CNES(国家空间研究中心)和CLS(集体定位卫星)于2010年5月20日成为国际全球导航卫星系统服务(IGS)分析中心。自2009年以来，我们在我们的软件包(GINS/Dynamo)中使用了将整周模糊度固定在零差水平的策略作为经典差分方法的替代。在此期间我们在GPS处理方面所做的所有改进中，这种方法起到了关键作用。本文向用户提供了计算每周提交给IGS的产品(GPS轨道和时钟、每周台站坐标估计和地球定位参数)的理论背景、策略和模型。详细描述了宽车道和窄车道两步模糊确定方案的具体实现。模糊度的确定改善了我们在切向和法向上的轨道重叠从6厘米到3厘米的WRMS。自2008年以来，IGS分析中心协调员还定期将我们的产品与IGS最终解决方案进行比较。模糊度的确定和动力学模型的改变(卫星太阳辐射压力和反照力)的共同作用提高了与IGS轨道的一致性，从35 mm到18 mm 3D-WRMS。我们的创新战略还为GPS卫星相位时钟解决方案提供了额外的强大特性。单接收机(零差)模糊度解算成为可能。并对其应用进行了概述。
CNES (Centre National d'Etudes Spatiales) and CLS (Collecte Localisation Satellites) became an International GNSS Service (IGS) Analysis Center (AC) the 20th of May 2010. Since 2009, we are using the integer ambiguity fixing at the zero-difference level strategy in our software package (GINS/Dynamo) as an alternative to classical differential approaches. This method played a key role among all the improvements in the GPS processing we made during this period. This paper provides to the users the theoretical background, the strategies and the models used to compute the products (GPS orbits and clocks, weekly station coordinate estimates and Earth orientation parameters) that are submitted weekly to the IGS. The practical realization of the two-step, ambiguity-fixing scheme (wide-lane and narrow-lane) is described in detail. The ambiguity fixing improved our orbit overlaps from 6 to 3 cm WRMS in the tangential and normal directions. Since 2008, our products have been also regularly compared to the IGS final solutions by the IGS Analysis Center Coordinator. The joint effects of ambiguity fixing and dynamical model changes (satellite solar radiation pressure and albedo force) improved the consistency with IGS orbits from 35 to 18 mm 3D-WRMS. Our innovative strategy also gives additional powerful properties to the GPS satellite phase clock solutions. Single receiver (zero-difference) ambiguity resolution becomes possible. An overview of the applications is given.