Improving Localization of Planetary Rovers with Absolute Bearing by Continuously Tracking the Sun

Abstract

Achieving meaningful exploration and discovery in our universe pivots on knowing where we are as we navigate the unknown. In many terrestrial cases this problem - the localization problem - has been remedied by precise a priori mapping of environments and developing advanced infrastructure such as global positioning satellites (GPS). However, extraterrestrial surface exploration robots do not have these absolute measurement tools at their disposal and achieving precise localization is still a limiting and time consuming problem. Even though it is essential to modern spacecraft and naval vessels, observing the sun and stars as absolute orientation references had, until now, not yet been fully exploited in real-time on surface rovers. Sun compassing has seen only limited, intermittent use on the moon and Mars for roving despite the potential for vastly increasing explorative capability. To this end, this work asserts that using a visual sun compass as a navigational aid to continuously determine absolute bearing substantially improves the ability of planetary rovers to navigate and localize, and supports this claim through the presentation of experimental results from the development and field testing of a high rate 187° field of view visual sun compass.