Determination of GNSS pseudo-absolute code biases and their long-term combination
Determination of GNSS pseudo-absolute code biases and their long-term combination
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DOI：
10.1007/s00190-019-01262-w
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发表时间：
2019-09-01
影响因子：
4.4
通讯作者：
Jaggi, Adrian
中科院分区：
文献类型：
--
作者：
Villiger, Arturo;Schaer, Stefan;Jaggi, Adrian
随着GPS的现代化以及诸如伽利略、北斗和QZSS的附加全球导航卫星系统（GNSS）星座的建立，越来越多的GNSS卫星可用在具有多个信号调制的各种频率上发射。为了科普日益增多的观测类型，常用的差分方法在簿记方面变得越来越困难。实际处理的原始观测类型必须事先已知，以在处理GNSS数据时定义线性独立的差分信号偏差（DSB）集合。代码偏差的另一种处理方法是使用可观测特定信号偏差（OSB），其中偏差的设置和校正变得微不足道。可以在建立正规方程（NEQ）之后考虑偏置参数的潜在依赖性，例如，在它被翻转之前。每天检索代码偏差结果并存储其NEQ。这允许将来自各种来源（或分析线）和不同时间段的联合收割机偏差结果组合。通过结合所有每日偏差NEQ，我们已经生成了一个连贯的多年偏差解决方案，从2000年到2017年，具有一个共同的数据。如果绝对接收器校准是可用的，themulti-year解决方案可以对准这些接收器，从而可以导致代码偏差的绝对估计。最后，估计的卫星OSB用于接收机兼容性分组测试，哪些接收机与哪些偏置集兼容。这可以通过求解所谓的OSB乘数来实现。
With the modernization of GPS and the establishment of additional global navigation satellite system (GNSS) constellations, such as Galileo, Beidou, and QZSS, more and more GNSS satellites are available transmitting on various frequencies with multiple signal modulations. In order to cope with the increasing number of observation types, the commonly used differential approach becomes more and more difficult regarding book-keeping. The actually processed original observation types have to be known in advance to define a linearly independent set of differential signal biases (DSB) while processing GNSS data. An alternative treatment of code biases is the usage of observable-specific signal biases (OSB) where the setup and correction of biases become trivial. Potential dependencies of the bias parameters can be considered after the setup of normal equations (NEQs), e.g., immediately before it is inverted. The code bias results are retrieved on a daily basis and their NEQs stored. This allows to combine bias results from various sources (or analysis lines) and different time periods. By combining all daily bias NEQs, we have generated a coherent multi-year bias solution from 2000 to 2017 with one common datum. If absolute receiver calibrations are available, themulti-year solution could be aligned to those receivers and thus could lead to an absolute estimation of the code biases. Finally, the estimated satellite OSBs are used for the receiver compatibility grouping testing which receivers are compatible with which bias sets. This may be achieved by solving for so-called OSB multipliers.