Development and evaluation of MWIR imaging spectrometer for multi-dimensional detection

Abstract

For the detection of moving target in complex background, in order to increase the identification ability, the sensor needs the ability of multi-dimensional detection, not only image and spectrum, but also motion features. We propose a multi-slit imaging spectrometer, in which multiple slits instead of the single slit are arranged along the track on the focal plane of the fore-optics. Thus, the moving target is imaged with spectral resolution multiple times in one scanning period, which obtains the time resolution. We have developed a prototype with three slits covering spectrum between 3 µm and 5 µm. The prototype utilizes a reflective triple optics and a prism yielding a compact spectrometer design, which makes it much easier to realize the large field of view, the fast optical speed, the high optical transmission efficiency, the compact volume, and cooled opto-mechanics. Results of the laboratory tests verify the satisfaction of the imaging quality and spectral characters. The flight test shows this type of imaging spectrometers with multiple slits is feasible in the multi-dimensional detection of moving targets. It deserves the expected value in satellites and airborne applications in the future.