Sky polarization and sun sensor system and method

Abstract

A system for determining a new orientation and/or position of an object comprises a sky polarimeter configured to record image data of the sky, a signal processing unit, and logic configured to receive and store in memory the image data received from the sky polarimeter. The logic calculates the Stokes parameters (S, S, S,), DoLP, and AoP from the image data, detects obscurants and filters the obscurants (such as clouds and trees) from the image data to produce a filtered image. The logic is further configured to find the Sun and zenith in the filtered image, and to determine the roll, pitch, yaw, latitude and longitude of the object using the filtered image. A method for determining a new position/orientation of an object comprises recording raw image data using a sky polarimeter, calculating S, S, S, DoLP, and AoP from the image data, detecting obscurants and filtering the obscurants from the image data to produce a filtered image, obtaining last known position/orientation data of the object, finding the Sun and zenith in the filtered image, and determining the roll, pitch, yaw, latitude and longitude of the object using the filtered image.