标题： 频率域中的GPS多路径检测 显示英文标题

标题： GPS Multipath Detection in the Frequency Domain

摘要： 多路径误差是精密GPS定位中的主要误差源之一，并且一直是广泛研究的对象。 本文提出了两种基于快速傅里叶变换（FFT）的检测器作为GPS多路径检测技术。 这些检测器被构造成二元假设检验，在假设多路径在足够长的时间段内存在，从而可以通过标量跟踪环路（STL）的同相早期-晚期鉴别器（Q EmL）的正交臂或者通过矢量跟踪环路（VTL）的正交（Q EmL）和/或同相臂（I EmL），使用N个样本的观测窗口来检测多路径。 所提出的检测器的性能分析是在德国航空航天中心（DLR）开发的多路径环境模拟器获取的多路径信号数据以及实际GPS信号的多路径数据上进行的。 将检测测试应用于标量和矢量跟踪环路的相关器输出表明，它们可以用于排除受多路径污染的卫星，以用于导航解算。 这些检测技术可以扩展到其他全球导航卫星系统（GNSS），如GLONASS、Galileo和北斗。 显示英文摘要

摘要： Multipath is among the major sources of errors in precise positioning using GPS and continues to be extensively studied. Two Fast Fourier Transform (FFT)-based detectors are presented in this paper as GPS multipath detection techniques. The detectors are formulated as binary hypothesis tests under the assumption that the multipath exists for a sufficient time frame that allows its detection based on the quadrature arm of the coherent Early-minus-Late discriminator (Q EmL) for a scalar tracking loop (STL) or on the quadrature (Q EmL) and/or in-phase arm (I EmL) for a vector tracking loop (VTL), using an observation window of N samples. Performance analysis of the suggested detectors is done on multipath signal data acquired from the multipath environment simulator developed by the German Aerospace Centre (DLR) as well as on multipath data from real GPS signals. Application of the detection tests to correlator outputs of scalar and vector tracking loops shows that they may be used to exclude multipath contaminated satellites from the navigation solution. These detection techniques can be extended to other Global Navigation Satellite Systems (GNSS) such as GLONASS, Galileo and Beidou.