METHOD FOR ESTIMATING BIASES IN THE MEASUREMENT SYSTEM OF A HEIGHT FINDING RADAR.

An analytical method is described based on data to be obtained by flight experiments for estimating biases of the range and depression angle measurement systems of a simple height finding radar (called NAMS) which uses a rotating fan beam antenna in a vertical plane. This method is based on the principle that the effects of biases on the height estimation error vary according to the geometric position of an aircraft relative to the radar head. Height estimation errors are estimated using the difference between the measured height of the aircraft by the radar and that by a barometric altimeter aboard the aircraft. Since the height estimation errors of NAMS can be approximated by a linear regression equation whose coefficients include biases of range and depression angle, the coefficients can be estimated by using the least squares method. The derivation of the linear regression equation is given first. Then the algorithm for height estimation is described.