Patent ID: 7447170

Claim:
A method for reducing the asymmetry error in a beacon, wherein the beacon comprises of multiple beams, and each beam is formed from a multiplicity of feed channels, comprising the step of: (a) computing beacon asymmetry angles, comprising the step of computing a difference between known azimuth/elevation angles, (az el), and their corresponding predicted beam-formed azimuth/elevation angles, (az c el c ):(az−az c el−el c ); and (b) using the beacon asymmetry angles to correct the beacon sensor measurements, including the step of using the beacon asymmetry angles as time-varying beacon bias angles; wherein the corresponding beam-formed azimuth/elevation angles are computed according to az c = K az ⁢ E 2 - W 2 E 2 + W 2 , and el c = K el ⁢ N 2 - S 2 N 2 + S 2 where K az and K el are optimal beacon slopes, and E, W, N, and S are East, West, North, and South beam magnitudes of the beacon beams.