Correction of frequency uncertainty in wide field of view interferometric angular velocity measurements

This paper presents a method for correcting the frequency uncertainty encountered in interferometric angular velocity measurements. This new technique of angular velocity measurement allows a wide field of view, where the frequency of the response is proportional to the angular velocity of the object. At wide angles, the measured frequency shift scales with the cosine of the angle, resulting in an uncertainty if the angular location of the object is not known. The correction method presented herein consists of estimating the angle of a signal using a wide-baseline interferometer with three closely spaced frequencies. With frequencies spaced over a fractional bandwidth of 3.5%, the residual uncertainty of the measured frequency shift is shown through simulation to be less than 0.1 Hz over a ±72° field of view with a 6 dB SNR.