and the monopulse radar system 30 based on a program stored in the rom 46 the cpu 42 processes the data stored in the ram 44 to generate the position of the object in antenna coordinates and to convert the position of the object in antenna coordinates into aircraft coordinates and or inertial coordinates any intermediate values produced during the processing of the data stored in ram 44 are also stored in ram 44 the position processor 40 utilizes the doppler frequency fd of the range doppler cell containing the object to determine the doppler angle u03b8 between the velocity vector of the aircraft and a line connecting the aircraft and the range doppler cell containing the object as shown in fig4 the doppler frequency fd of the range doppler cell is known to the accuracy of the rf reference oscillator accuracy for the monopulse radar system 30 modified by a value which is roughly equivalent to the width of the frequency of the range doppler cell the doppler angle u03b8 is calculated using the following equation where u03b8 is the doppler angle u03bb is the wavelength of the output pulse from the monopulse radar system 30 fd is the doppler frequency of the range doppler cell and v is the velocity of the aircraft from the ins 14 additionally as discussed with respect to equation 2 the following expression defines a relationship between the doppler angle u03b8 and the elevation el and azimuth az of the range doppler cell containing the object accordingly knowledge of the doppler angle u03b8 and one of the elevation el and the azimuth az.