Attitude calculation method based on full-sky atmospheric polarization mode.

In the natural world, insects such as bees and sand ants can navigate with the aid of polarized skylight. Inspired by this, bio-inspired navigation systems based on polarized skylight have attracted considerable attention recently. As an important navigation parameter, attitude information is critical for control and navigation of a vehicle. In this paper, the structural characteristics of full-sky atmospheric polarization mode are studied to calculate the attitude of a vehicle relative to the observation point. The heading angle is obtained by subtraction between two angles. One is the angle between the solar meridian and the geographic north. The other is the angle between the solar meridian and the body coordinate system, which can be obtained from the polarization data detected by the sensor. And the solar position can also gain from the polarization data. Then based on the solar position and the coordinates of solar projection point, the zenith point can be determined. With the coordinates of the zenith point in the body and the reference coordinate system, the pitch angle and roll angle are solved. Simulation and practical experiments are conducted to validate the performance of the attitude calculation method. Experiment results with high accuracy show its feasibility and effectiveness.