Passive optical sensing of atmospheric polarization for GPS denied operations

There is a rapidly growing need for position, navigation, and timing (PNT) capability that remains effective when GPS is degraded or denied. Naturally occurring sky polarization was used as long ago as the Vikings for navigation purposes. With current polarimetric sensors, the additional polarization information measured by these sensors can be used to increase the accuracy and the availability of this technique. The Sky Polarization Azimuth Sensing System (SkyPASS) sensor measures this naturally occurring sky polarization to give absolute heading information to less than 0.1° and offers significant performance enhancement over digital compasses and sun sensors. SkyPASS has been under development for some time for terrestrial applications, but use above the atmosphere may be possible and the performance specifications and SWAP are attractive for use as an additional pose sensor on a satellite. In this paper, we will describe the phenomenology, the sensor performance, and the latest test results of terrestrial SkyPASS; we will also discuss the potential for use above the atmosphere and the expected benefits and limitations.

[1]  R. L. Lee,et al.  Digital imaging of clear-sky polarization. , 1998, Applied optics.

[2]  Albert J. P. Theuwissen,et al.  Integrated polarization-analyzing CMOS image sensor , 2010, Proceedings of 2010 IEEE International Symposium on Circuits and Systems.

[3]  W. Steen.  Absorption and Scattering of Light by Small Particles , 1999 .

[4]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .

[5]  Ille C. Gebeshuber,et al.  Bio-Inspired Polarized Skylight-Based Navigation Sensors: A Review , 2012, Sensors.

[6]  Joseph A. Shaw,et al.  Comparison of full-sky polarization and radiance observations to radiative transfer simulations which employ AERONET products. , 2011, Optics express.

[7]  Art Lompado,et al.  Using Atmospheric Polarization Patterns for Azimuth Sensing , 2014, Defense + Security Symposium.

[8]  Albert J. P. Theuwissen,et al.  Biologically inspired autonomous agent navigation using an integrated polarization analyzing CMOS image sensor , 2010 .

[9]  Katsushi Ikeuchi,et al.  Estimating Sunlight Polarization Using a Fish-eye Lens , 2009, IPSJ Trans. Comput. Vis. Appl..

[10]  R. Wehner,et al.  Polarization patterns of the summer sky and its neutral points measured by full–sky imaging polarimetry in Finnish Lapland north of the Arctic Circle , 2001, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[11]  Joseph A Shaw,et al.  Digital all-sky polarization imaging of partly cloudy skies. , 2008, Applied optics.

[12]  Raymond L Lee,et al.  Spectral polarization of clear and hazy coastal skies. , 2012, Applied optics.

[13]  John William Strutt,et al.  XV. On the light from the sky, its polarization and colour , 1871 .

[14]  Q. Fu,et al.  Mie theory for light scattering by a spherical particle in an absorbing medium. , 2001, Applied optics.

[15]  吴敏华,et al.  The Novel Method of North-finding Based on the Skylight Polarization , 2013 .

[16]  Glenn S. Smith.  The polarization of skylight: An example from nature , 2007 .

[17]  G. Horváth,et al.  How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation. , 2001, The Journal of experimental biology.

[18]  Joseph A Shaw,et al.  Effects of surface reflectance on skylight polarization measurements at the Mauna Loa Observatory. , 2011, Optics express.

[19]  Gábor Horváth,et al.  Polarization patterns of thick clouds: overcast skies have distribution of the angle of polarization similar to that of clear skies. , 2007, Journal of the Optical Society of America. A, Optics, image science, and vision.

[20]  J. Hansen.  Multiple Scattering of Polarized Light in Planetary Atmospheres Part II. Sunlight Reflected by Terrestrial Water Clouds , 1971 .

[21]  J. Strutt.  Scientific Papers: On the Transmission of Light through an Atmosphere containing Small Particles in Suspension, and on the Origin of the Blue of the Sky , 2009 .