Unpolarized light from the Sun incident upon the Earth’s atmosphere becomes polarized and presents a polarization pattern in the viewable sky dome that depends on the position of the Sun, the viewer’s position on the Earth, and the time of the observation. In clear and slightly overcast skies, both the degree of linear polarization and the polarization orientation can be predicted to first order using Rayleigh scattering theory. Conversely, measuring this polarization pattern provides information about the pose of a sensing platform equipped with an imaging polarimeter. We present here an investigation of the predicted polarization patterns in conjunction with a set of polarimetric measurements to show how the pointing direction of the platform hosting the polarimeter can be recovered. This direction derives solely from the measured polarization of a subsection of the hemispherical polarization pattern centered near the zenith and can be determined to high accuracy.

Date Published: 3 June 2014
PDF: 11 pages
Proc. SPIE 9085, Sensors and Systems for Space Applications VII, 90850B (3 June 2014); doi: 10.1117/12.2054107

Published in SPIE Proceedings Vol. 9085:
Sensors and Systems for Space Applications VII
Khanh D. Pham; Joseph L. Cox, Editor(s)