GPS antenna array calibration for attitude determination based on reference phase difference method

This paper presents a method of improving attitude parameters' accuracy by solving a problem of unknown phase center. The carrier phase GPS concept is used to achieve precise attitude parameters (pitch, roll and yaw angles). The typical problem of unknown phase center is solved using antenna array calibration based on reference phase differences. Values of reference phase differences are calculated for all possible angles combinations. Most previous techniques to solve the problem of phase center determination have required precisely known attitude parameters. The new method has the advantage over other methods by operating with unknown angles. For proper operation antenna array should be calibrated directly on navigation object. The new algorithm described in this paper assumes antenna array calibration onboard. Moreover, suggested approach has the ability to calibrate antenna array with baselines of 10-20 wavelengths. Efficiency of described calibration algorithm is expressed in terms of angles accuracy.