Laser altimeter for use over the ocean
By: E.C. Crittenden, Jr., G.W. Rodeback, A.W. Cooper, and C.M. Bourne
Contributors: Rodeback, George Wayne; Cooper, Alfred William; Bourne, Carlton M.; Naval Postgraduate School (U.S.). Dept. of Physics
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1989
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 73
Subjects: LASERS; REMOTE DETECTORS; FALSE ALARMS; RADIO ALTIMETERS; GALLIUM ARSENIDES; OPTICAL RADAR
Other titles: NPS-61-89-001.
Description: A pilot model of a small size, mass, power, and cost, GaAs laser radar altimeter has      been developed and tested for use over the ocean. Two versions have been developed,      one for triggering a device at a predetermined altitude, and one for providing an altitude      'read out' as an analog dc voltage. Field tests from a bridge over an inland reservoir      indicate performance with negligible false-alarm rate up to an altitude of 400 meters      over the ocean, under all sea-state conditions, from glassy calm to the 'worst-case'      rough sea state condition, and with the sun vertically overhead. A new remote sensing      technique was developed to evaluate the roughness state of the water during field tests      and to predict the mean laser return signal. This utilizes video imaging of the glitter      pattern on the water from a bright point source light at night, or from the sun in the      daytime. Tests of the altimeter over the ocean surface at sea are still needed, because      extrapolation from ripples on the inland reservoir to full scale ocean waves is not fully      understood. (rh)
Notes: Title from cover.

"NPS-61-89-001."

"April 1989."

"Final report for period October 1987 - September 1988."

AD A211 252.

Includes bibliographical references (p. 73)

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