Polarimetric Calibration and Characterization of the Telops Field Portable Polarimetric-Hyperspectral Imager.

摘要

The Telops polarimetric-hyperspectral imager combines polarimetric and hyperspectral technologies to enable enhanced scene characterization. The Defense Threat Reduction Agency funded research at AFIT to leverage this capability to provide more accurate scene information to radiation transport models that will allow for more effective location of radiation sources within a region of interest. To support the objectives of the DTRA effort, there is a requirement for highly accurate radiometric, polarimetric, and spectral data on a pixel-by-pixel basis. The complex nature of the Telops instrument combined with working in the thermal IR waveband makes achieving this accuracy a challenge. This thesis develops a calibration methodology that enables high data accuracy in all three domains. In the process, a mathematical calibration framework was developed that links standard Fourier transform spectrometer (FTS) calibration with standard polarimetric calibration in a straightforward manner. This provided a framework for understanding the influence of various instrument parameters (both ideal and non-ideal) on ultimate calibration performance. The framework developed is utilized to quantify the non-idealities of the system and to characterize the performance of the spectro-polarimetric calibration. Additionally, fundamental performance limits are characterized including the noise equivalent spectral radiance and noise equivalent degree of linear polarization of the system.