The application of extended Kalman filtering to the Position Locating Reporting System (PLRS)

Abstract

Extended Kalman filtering is applied to the PLRS (Position Locating Reporting System). Here the nonlinearity to the filter enters through the measurement (range only). The nonlinearity being the relationship between range and the Cartesian coordinate states of the filter. Filter covariances of error are portrayed as error ellipsoids. these are used to determine which one should be used to update a unit when there are several other units available for ranging. One should attempt to make the range measurement is the same direction of the major axis of error associated with the unit to be updated. The filtering techniques are evaluated using static units and high speed maneuvering aircraft.