DESIGN OF A MULTISPECTRAL SENSOR

Optomechanical scanners have a revolving mirror and discrete detector elements for different spectral bands. The lower integration time in t hese systems affects the SNR, which can be improved either by increasi ng the collecting aperture or by using more sensitive detectors. An in crease in the collecting aperture causes an enormous increase in the t otal weight of the scanner system. CCD image sensors have better sensi tivity than the discrete detector elements. Linear CCD image sensors m ake it possible to avoid the use of revolving mirrors that are require d in optomechanical scanners. CCD image sensors have a wide spectral r esponse that makes them particularly suitable for multispectral imagin g. The design of a multispectral sensor consisting of a single lens an d a complex prism with dichroic and total internal reflecting surfaces is presented. It provides accurate band-to-band registration and rugg ed construction. The acquired image is displayed on a UV sensitive pap er in real time.