We describe a new type of Calibrated Hyperspectral Image Projector (CHIP) intended for radiometric testing of instruments ranging from complex hyperspectral or multispectral imagers to simple filter radiometers. The CHIP, based on the same digital mirror arrays used in commercial digital light projector* (DLP) displays, is capable of projecting any combination of as many as approximately one hundred different arbitrarily programmable basis spectra into each pixel of the instrument under test (IUT). The resulting spectral and spatial content of the image entering the IUT can simulate, at typical video frame rates and integration times, realistic scenes to which the IUT will be exposed during use, and its spectral radiance can be calibrated with a spectroradiometer. Use of such generated scenes in a controlled laboratory setting would alleviate expensive field testing, allow better separation of environmental effects from instrument effects, and enable system-level performance testing and validation of space-flight instruments prior to launch. Example applications are testing the performance of simple fighter-fighter infrared cameras under simulated adverse conditions, and system level testing of complex hyperspectral imaging instruments and algorithms with realistic scenes. We have built and tested a successful prototype of the spectral light engine, a primary component of the CHIP, that generates arbitrary, programmable spectra in the 1000 nm to 2500 nm spectral range. We present an overview of this technology and its applications, and discuss experimental performance results of our prototype spectral light engine.
Pub Type: Journals
hyperspectral, image, infrared, micromirror, projector, radiometry