Six band multispectral sensor using off-axis three-mirror reflective optics

This paper describes design and experimental results for the future airborn e multispectral sensor with six bands between visible and infrared regions. The multispectral sensor features single optics using off-axis three-mirro r reflective optics to provide same field of views for all six bands and di chroic mirrors to separate the spectral range into six bands. The off-axis three-mirror optics provides an obstruction free FOV with a wide spectral r ange and high spatial resolution over a wide FOV. The six bands consist of three visible bands, a near infrared band, an MWIR band and an LWIR band. T he 10,000 element CCD sensors are used for the three visible bands and the near infrared band. The 960 element HgCdTe linear arrays are used for the M WIR and the LWIR bands. The results of experiments reveal that the ground-b ase multispectral sensor has a wide spectral range from 0.4 mum to 10 mum, the wide FOV over 5.7 degrees and the high spatial resolutions of less than 10 mu rad for visible and near infrared bands and of less than 104 mu rad for the MWIR and the LWIR bands. The overall MTF at the center of the FOV i s more than 0.3 at Nyquist frequency for all bands. (C) 2000 Society of Pho to-Optical Instrumentation Engineers. [30091-3286(00)01110-7].