Anil B. Chaudhary, Tamara E. Payne, Keith Lucas, Shaylah Mutschler, Tim Vincent, Applied Optimization, Inc., Phan Dao, Jeremy Murray-Krezan, (Air Force Research Laboratory /RVBY)
Keywords: physics-based signature inversion, data point pairing, BRDF coordinate frame, two-facet model, three-axis stabilized satellites
Abstract:
The point pairing method in this paper is based on set of simple physical truths for three-axis stabilized space objects in the geosynchronous orbit (GEO). It defines a method for the calculation of pairs of observation conditions (i.e. point pairs) that have a special property for three-axis stabilized GEO object characterization. An observation condition is defined to be the geometry of illumination for the solar panel and the body of the satellite and the geometry of its observation by a sensor. The physical truths are due to observation conditions that are equivalent with respect to either the solar panel or body for a pair of points, which can be identified analytically. When the observation conditions are equivalent for the solar panel, the contribution to the GEO object brightness by the solar panel at those pair of points is identical. Then the difference between the pair of brightness values cancels the solar panel contribution unconditionally and the remainder is only due to the body. Similarly, when the contribution of the body to the observed brightness is same for the point pair, the difference between the two brightness values cancels the body contribution unconditionally and the remainder is only due to the solar panels. This enables separation of the observed brightness data into contributions by the solar panels and the body, which is fundamental to space-object characterization. This separation of the solar panel or body contributions is feasible in each waveband of observation. Thus the point pairing is useful for the analysis of panchromatic as well as multi-spectral data. The desired observation conditions for point pairing occur routinely, typically within a week of each other. This work is supported by the Space Vehicles Directorate of the Air Force Materials Laboratory.
Date of Conference: September 10-13, 2013
Track: Non-Resolved Object Characterization’