Multipath Effects in GPS Navigation

摘要

GPS based range measurements suffer from a variety of errors, e.g. satellite clock drift, satellite ephemeris, ionospheric delay, tropospheric delay, receiver clock biases and signal multipath. Errors related to orbit prediction, satellite timing, atmosphere can be removed by differencing technique or significantly reduced by modelling. Measurement errors caused by multipath behave in a different manner due to the fact that multipath depends greatly upon the positioning of transmitting and receiving antennas and also on the geographical location of the receiving antenna. The errors caused by multipath can be at the meter level and presence of this amount of error severely affects the accuracy levels in measurements. This paper deals in brief the effects of multipath and its mitigation.