Isolating Multi-Path Effects From the Position Estimate Residuals in GPS Receivers
Multi-path reflections can cause GPS receiver devices to mis-calculate their location. Errors due to multi-path will tend to bias the position estimate from the true value. The redundancy of satellites can be utilized to identify a single source of error. The estimated residual error is an artifact of the least squares estimate process. After the estimate is computed, the residual estimate error from each satellite should be uniform. If it is not, the satellite signal associated with the largest errors may have come to the receiver along a reflected path. Once identified, the corrupted pseudo-range can be removed from the estimator. The detection technique is described. A simulation study is undertaken to determine the best detection threshold for typical use scenarios.