Tuning fork MEMS gyroscope for precision northfinding

We report northfinding results using an out-of-plane tuning-fork MEMS gyroscope with performance approaching navigation grade. Angle random walk is less than 0.003 °/√hr, and in-run bias instability is less than 0.02 °/hr at an Allan variance sampling time of one hour. A compact (<; 20 cm
³
) prototype northfinder containing 3 gyros and 3 accelerometers is indexed to compensate for gyro and accelerometer bias drift and non-repeatability, providing northfinding precision of ±4 milliradians in 4 minutes averaging time. Gyro magnetic sensitivity is less than 0.004 °/hr/Gauss.