Polarization Navigation Simulation System and Skylight Compass Method Design Based upon Moment of Inertia

Huaju Liang,Xiubao Sui,Hongyang Bai,Ning Liu

doi:10.1155/2020/4081269

Abstract

Unpolarized sunlight becomes polarized by atmospheric scattering and produces a skylight polarization pattern in the sky, which is detected for navigation by several species of insects. Inspired by these insects, a growing number of research studies have been conducted on how to effectively determine a heading angle from polarization patterns of skylight. However, few research studies have considered that the pixels of a pixelated polarization camera can be easily disturbed by noise and numerical values among adjacent pixels are discontinuous caused by crosstalk. So, this paper proposes a skylight compass method based upon the moment of inertia (MOI). Inspired by rigid body dynamics, the MOI of a rigid body with uniform mass distribution reaches the extreme values when the rigid body rotates on its symmetry axes. So, a whole polarization image is regarded as a rigid body. Then, orientation determination is transformed into solving the extreme value of MOI. This method makes full use of the polarization information of a whole polarization image and accordingly reduces the influence of the numerical discontinuity among adjacent pixels and measurement noise. In addition, this has been verified by numerical simulation and experiment. And the compass error of the MOI method is less than 0.44° for an actual polarization image.

Highlights

Unpolarized sunlight becomes polarized after being scattered by gas molecules, dust, aerosols, and other scatters in the atmosphere and produces polarization patterns in the sky
A more comprehensive study should consider the fact that the pixels of a pixelated polarization camera can be disturbed by noise and the numerical values among adjacent pixels are discontinuous caused by crosstalk [15, 16]. To address this technology gap, this paper proposes a new methodology for orientation determination based on symmetry axis extraction using the moment of inertia (MOI), which makes full use of the symmetry characteristics of the whole sky to determine orientation and reaches a high level of stability
In order to suppress the interference of measurement noise and numerical discontinuity among pixels of the pixelated polarization camera, in this paper, a skylight compass method based on MOI is proposed, which extracts the symmetry axis of the whole skylight polarization pattern to determine orientation. en, based on the Rayleigh sky model, a simulation system is constructed to validate the MOI method

Summary

Introduction

Unpolarized sunlight becomes polarized after being scattered by gas molecules, dust, aerosols, and other scatters in the atmosphere and produces polarization patterns in the sky. A more comprehensive study should consider the fact that the pixels of a pixelated polarization camera can be disturbed by noise and the numerical values among adjacent pixels are discontinuous caused by crosstalk [15, 16] To address this technology gap, this paper proposes a new methodology for orientation determination based on symmetry axis extraction using the moment of inertia (MOI), which makes full use of the symmetry characteristics of the whole sky to determine orientation and reaches a high level of stability. In order to suppress the interference of measurement noise and numerical discontinuity among pixels of the pixelated polarization camera, in this paper, a skylight compass method based on MOI is proposed, which extracts the symmetry axis of the whole skylight polarization pattern to determine orientation. A field experiment using a polarized skylight navigation platform is carried out

Orientation Determination Algorithm Design

Polarization Navigation Simulation System

Simulation and Experiment

Findings

Method