Westinghouse Electric Corporation

Fred L Schaff

Leslie L Thompson

An acousto-optic spectrometer/polarimeter for analyzing an incident broad-band beam including an acousto-optic tunable filter (AOTF) for separating the incident broad-band beam into a diffracted extraordinary narrow-band beam, a diffracted ordinary narrow-band beam, and at least one undiffracted broad-band beam; first, second and third detectors respectively positioned to respectfully receive at least a portion of the diffracted extraordinary narrow-band beam, the diffracted ordinary narrow broad-band beam and the at least one undiffracted broad-band beam, and to respectively provide first, second and third signals based thereon; a subtracter for providing a polarimeter output by taking the difference between the first and the second signals; and an adder for providing a spectrometer output by adding the first and the second signals. The acousto-optic spectrometer/polarimeter according to the present invention allows broad-band imaging, spectroscopy and polarimetry to be performed simultaneously and through the same optical aperture.

Acousto-optic spectrometer/polarimeter

An imaging radiometer for scanning an area of interest from a platform moving in an orbital trajectory comprises at least one moving scanning mirror directed toward the area of interest. The mirror produces a changing scan area image representing a portion of the area of interest within the scan area of the mirror. A fixed optical viewer is mounted on the platform for viewing the scan area image and directing the image along its optical path. A detector in the optical path receives the changing scan area image over a selected time interval and periodically produces an electrical output, each output representing a different scan area image of the mirror over each time interval. In one embodiment the detector has a plurality of areas of different spectral response. Image motion compensation, electronically controlled light intensity gain and electronically controlled image size correction are incorporated in the apparatus.

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Ellicott City, MD, United States of America

Fred L Schaff