Bio-Inspired Polarization Compass for Solar Azimuth Prediction

Abstract

Navigation is a crucial requirement for numerous applications in modern society. Global navigation satellite system, inertial measurement unit and magnetic compass are currently among the most commonly used for navigation. These devices may not provide satisfactory solutions for navigation in many real-life scenarios. Light reaching earth from celestial bodies including sun and moon becomes polarized while passing through earth’s atmosphere due to Rayleigh scattering. Analysis of the polarization state of light allows insects including ants, bees, and monarch butterflies to estimate the position of sun or moon and use it for charting and maintaining a navigation plan. Development of polarization compasses that mimic this principle for heading determination has attracted a lot of interest in recent years. Although significant progress has been made, the devices still do not meet the requirements of accuracy, speed, and cost for practical application. The purpose of this thesis is to overcome some of these challenges. We developed working prototypes of a polarization compass. We investigated application of stochastic gradient method, support vector machine and linear regression for heading determination. Our work indicates that there is a strong possibility that polarization compasses may become a useful navigational aid for many applications in the near future.