Initial alignment on moving base using GPS measurements to construct new vectors

Strapdown inertial navigation system cannot easily implement initial alignment on moving base if without the prior “one shot” transfer from another master inertial navigation system and strict constraints on moving trajectory, because the initial coarse attitude cannot be effectively achieved. In this paper, a novel method using the GPS measurements to assist to solve initial attitude matrix is investigated as coarse alignment. Specific vectors are constructed with GPS measurements and used for attitude matrix computation like in analytic alignment algorithm. Several moving conditions of carrier are assumed to test the new alignment method, and the results indicate that the initial attitude angles can be achieved with small errors, which is suitable for the conventional fine alignment afterward.