A Novel Orientation Method for Polarized Light Compass Under Tilted Conditions

In this paper, we propose a novel method to improve the orientation accuracy of polarized light compass under tilted conditions. It firstly calculates the skylight polarization pattern utilizing the horizontal attitude angle, and then extracts the solar meridian by dynamically finding the image region receiving skylight from zenith area. The advantage of this method is that it always uses the polarization information of the zenith area to calculate the carrier's heading and establishes a unified external reference. We also quantitatively analyze the orientation errors of polarized light compass caused by neglecting the horizontal attitude angle. Outdoor experimental results show that under severe tilted conditions, the accuracy of proposed orientation method is about 1°, while the conventional method only has an accuracy of 4°. To our best knowledge, this is the first work to systematically analyze the orientation problem of polarized light compass under tilted conditions.