Abstract: Aiming at the problem that the classical mechanizations of inertial navigation system in polar region are unable to confirm its position and heading, a new polar navigation scheme based on frozen geography frame was proposed, which is suitable for strapdown inertial navigation system. This scheme uses threeaxis position instead of longitude, latitude and altitude for navigation in polar region. This algorithm has no singularity in navigation calculation. The mechanizations under the frozen geography frame were given. The parameter transformations from a frozen geography frame to geography frame for position, velocity and attitude were deduced. The simulation and analysis results show that this method can solve the problem that the north benchmark is invalid, and that the navigation parameters are continuous and have no theoretical errors. The mechanizations under the frozen geography frame can meet the requirement of  transpolar aircraft.

Key words: polar navigation, strapdown inertial navigation, frozen geography frame, simulation and analysis, navigation algorithm