Error analysis of analytic coarse alignment methods

Two analytic coarse alignment methods and the associated error analyses are provided for strapdown inertial navigation systems. Although both methods are derived from the same measurements of the local gravity vector and Earth rate, their error formulations are not completely identical. By properly selecting the basis to compute a best estimate of transformation matrix, the drift misalignment angles of analytic alignment can be made to be equivalent to those which can be found by physical gyrocompassing.