Philip Andrew Pruitt

US Patent:

6573982, Jun 3, 2003

Filed:

Sep 18, 1991

Appl. No.:

07/762094

Inventors:

Philip Andrew Pruitt - San Diego CA

Assignee:

Raytheon Company - Lexington MA

International Classification:

G01C 308

US Classification:

356 501, 356 285, 342132

Abstract:

A frequency jitter compensation radar system which frequency modulates a transmitter laser beam with simultaneously generated up- and down-chirped frequency modulated signals. The frequency modulated transmitter beam is used to scan a target and a reflected light beam is received for each pixel location of a radar system. The reflected light beam is heterodyned with a local oscillator laser beam and upon detection two separate electrical signal channels are provided representing tb up- and down-chirped frequency modulated signals. These up- and down-chirped signal channels are compressed and are further processed as the return signals of a radar system as by averaging the peak detection measurement from the two channels for each pixel to provide frequency jitter compensation commonly resulting from speckle from a target. Electro-optic or acoustic-optic arrangements may be used to frequency modulate the transmitter laser beam. Surface acoustic wave filters may be used for demodulation of the received signal channels.