Enhanced Target Detection Under Poorly Illuminated Conditions

We demonstrate an enhanced ACE target detection algorithm for poorly illuminated and shadowed pixels in which image segmentation based on illumination is performed prior to target detection. This enhanced ACE detection method (ACE-shadow) relies on FLAASH-based scene atmospheric correction and MODTRAN-calculated direct to diffuse illumination ratios to model shadowed target spectra. Improvements to target detection were realized using our ACE-shadow detection algorithm because SNR characteristics of shadowed pixels dominate the segmented covariance.