Patent ID: 8099876

Claim:
An azimuth determination system comprising: a platform; a plurality of gimbals attached to the platform to allow the platform to rotate about multiple axes; a pair of gryos attached to the platform; a leveling device attached to the platform to indicate when the platform is at a desired position; a control device attached to the plurality of gimbals to move the platform to the desired position indicated by the leveling device; and an electronics system to provide power to the azimuth determination system and to determine azimuth by positioning the gyros in a first position with an input axis of the gyros orthogonal to the Earth Rate vector to calculate a first output and rotating the gyros 180° about the vertical to a second position to calculate a second output, the platform inverted and rotated to calculate a third and fourth outputs, wherein the four outputs are combined to produce the azimuth value and gyro induced bias error.