Exploration of Whether Skylight Polarization Patterns Contain Three-dimensional Attitude Information

TL;DR

This paper investigates whether skylight polarization patterns contain 3D attitude information by proposing a social spider optimization method and a comprehensive sky model, revealing potential for 3D attitude estimation under ideal conditions.

Contribution

It introduces a novel SSO-based method and a combined sky model to explore 3D attitude information in skylight polarization patterns, extending beyond traditional Rayleigh model limitations.

Findings

SSO algorithm can estimate 3D attitude in simulations

Sky model incorporating AOP, DOP, and LI contains 3D attitude information

Estimation accuracy decreases with noise and model errors

Abstract

Our previous work has demonstrated that Rayleigh model, which is widely used in polarized skylight navigation to describe skylight polarization patterns, does not contain three-dimensional (3D) attitude information [1]. However, it is still necessary to further explore whether the skylight polarization patterns contain 3D attitude information. So, in this paper, a social spider optimization (SSO) method is proposed to estimate three Euler angles, which considers the difference of each pixel among polarization images based on template matching (TM) to make full use of the captured polarization information. In addition, to explore this problem, we not only use angle of polarization (AOP) and degree of polarization (DOP) information, but also the light intensity (LI) information. So, a sky model is established, which combines Berry model and Hosek model to fully describe AOP, DOP, and LI information in the sky, and considers the influence of four neutral points, ground albedo, atmospheric turbidity, and wavelength. The results of simulation show that the SSO algorithm can estimate 3D attitude and the established sky model contains 3D attitude information. However, when there are measurement noise or model error, the accuracy of 3D attitude estimation drops significantly. Especially in field experiment, it is very difficult to estimate 3D attitude. Finally, the results are discussed in detail.