Surface Material Characterization from Non-resolved Multi-band Optical Observations
AIR FORCE RESEARCH LAB KIHEI MAUI HI DETACHMENT 15
Pagination or Media Count:
Ground-based optical and radar sites routinely acquire resolved images of satellites. These images provide the means to construct accurate wire-frame models of the observed body, as well as an understanding of its orientation as a function of time. Unfortunately, because such images are typically acquired at a single wavelength, this kind of analysis provides little or no information on the types of materials covering the satellite s various surfaces. Detailed surface material characterization generally requires multi-band radiometric andor spectrometric measurements. Many widely-available instruments provide such multi-band information e.g., spectrographs and multi-channel photometers. However, these sensors typically measure the brightness of sunlight reflected from the entire satellite, with no spatial resolution at all. Because such whole-body measurements represent a summation of contributions from many reflecting surfaces, an un-mixing analysis must be employed to characterize the reflectance of the satellite s individual sub-components. The objective of this paper is to outline the theory required for such an unmixing process, focusing on two newly-developed analysis methods. Both methods retrieve satellite surface properties from temporal sequences of whole-body brightness measurements.
- Unmanned Spacecraft