Multipath effects on the determination of absolute ionospheric time delay from GPS signals
Multipath effects on the determination of absolute ionospheric time delay from GPS signals
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DOI：
10.1029/rs020i003p00388
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发表时间：
1985-05
期刊：
影响因子：
1.6
通讯作者：
G. Bishop;J. Klobuchar;P. Doherty
中科院分区：
文献类型：
--
作者：
G. Bishop;J. Klobuchar;P. Doherty
来自全球定位系统（GPS）卫星的信号可用于测量绝对电离层群延迟和相对相位超前。这些电离层参数在为需要电离层时间延迟和相位闪烁知识的军事系统（如卫星探测雷达）提供校正方面具有广泛的应用。来自接收天线的局部环境的多径效应可对用GPS伪随机噪声接收机进行的电离层群延迟测量造成严重的污染。在一些典型的清洁和反射环境中的多径效应的测量变化，并示出与伪随机噪声接收机的信号分析是一致的。测量的单反射器多径进行了简要分析，并显示出良好的相关性与计算。由于天线必须经常位于远低于理想的环境中，数据分析程序被开发用于最小化多径对群延迟测量的影响。这些方法包括低通滤波、逐日相关和使用绝对电离层群延迟数据的子集对相对差分载波相位超前测量进行校准。这些过程的结果适用于从各种多径环境的测试数据。
Signals from the Global Positioning System (GPS) satellites can be used to make measurements of absolute ionospheric group delay and relative phase advance. These ionospheric parameters have wide application in providing corrections for military systems requiring knowledge of ionospheric time delay and phase scintillation, such as satellite detection radars. Multipath effects from the local environment of the receiving antenna can cause severe contamination of ionospheric group delay measurements made with GPS pseudorandom noise receivers. Measured variations in the multipath effects in some typical clean and reflective environments are presented and shown to be consistent with signal analysis for pseudorandom noise receivers. Measured single reflector multipath is analyzed briefly and shown to correlate well with calculations. Since antennas must frequently be located in environments that are much less than ideal, data analysis procedures were developed for minimizing the impact of multipath on the group delay measurement. These include low-pass filtering, day-to-day correlation, and calibration to relative differential carrier phase advance measurements by using subsets of the absolute ionospheric group delay data. Results of these processes as applied to the test data from various multipath environments are presented.