Factors controlling discrimination in imaging polarimetry

摘要

The discrimination of scene elements in polarimetric and in non-polarimetric images is governed by both environmental and instrumental factors. These factors consist of systematic elements, which are dealt with by means of appropriate calibration, and random errors. In the case of imaging polarimetry, the Stokes parameter images are calculated from images obtained with orthogonal orientations of the linear polarizer about the optic axis. For the Stokes images to contain significant information, the orthogonal, registered image pair from which the Stokes images S_1 and S_2 are calculated must be significantly different. Misregistration of the orthogonal input images also impacts the correlation of the resulting Stokes image to scene elements. The system MTF, sampling pattern and geometry further impact the discrimination of features in the scene. These factors are discussed. The effects of systematic and random error sources on resolved target discriminability from clutter background is considered in depth. While the issue of spatially unresolved target detection is considered, it does not form a major component of this discussion. The intent of these considerations of the physics and phenomenology of imaging polarimetry is to progress towards the predictive modeling of target discriminability. This will aid in sensor design and mission parameter optimization.