Effect of biased measurement errors on accuracy of position location methods

The effect of measurement biases on the accuracy of position location techniques with time of arrival (TOA) and time difference of arrival (TDOA) measurements is investigated. Some of the factors that cause measurement biases are lack of line of sight propagation, multipath effects and hardware calibration errors. Such biases are modelled as being constant over the position measurement interval, and the effect of these biases is investigated through the use of a circular error probability measure. It is shown that biased measurement errors may cause significant degradation in performance.