<title>Common Module Imaging Spectral Radiometer</title>

Chemical vapor detection with a multispectral thermal imager

“…The filters should be mounted far enough from the detector to avoid large noise contributions due to forward scattering from small defects, which generally exist in the filter patches. This scattering is called the Stierwalt [1][2][3][4][5][6][7][8][9][10][11][12][13] Since the filters are fabricated from 1/4-wavelength thickness layers sequentially applied, any foreign material that adheres to the filter during fabrication will result in a feature as shown in Commercial infrared filters generally contain some of these defects. Because the filters are not generally mounted close to the detector, the defects have no effect.…”