Multipath effects on the determination of absolute ionospheric time delay from GPS signals

摘要: Signals from the Global Positioning System (GPS) satellites can be used to make measurements of absolute ionospheric group delay and relative phase advance. These parameters have wide application in providing corrections for military systems requiring knowledge time scintillation, such as satellite detection radars. Multipath effects local environment receiving antenna cause severe contamination made with GPS pseudorandom noise receivers. Measured variations multipath some typical clean reflective environments are presented shown consistent signal analysis single reflector is analyzed briefly correlate well calculations. Since antennas must frequently located that much less than ideal, data procedures were developed minimizing impact on measurement. include low-pass filtering, day-to-day correlation, calibration differential carrier advance by using subsets data. Results these processes applied test various presented.