Calibration of a Timing Skew between Gyroscope Measurements in a Strapdown Inertial Navigation System

Abstract

We present a method for a microsecond-level calibration of a constant timing skew between gyroscope channels in an inertial measurement unit of navigation grade. In our method, special types of harmonic oscillations applied to the inertial system produce predictable attitude error growth related to the timing skew. We obtain its estimates in a manner that makes the result insensible to the possible residual errors in inertial sensor calibration and other instrumentation. Apart from parameters of oscillations, the method requires essentially no other information but the standard navigation output of the inertial unit. Two case studies demonstrate the practical utility of the suggested approach.