COMPACT LIDAR FOR SIMULTANEOUS RANGE AND VELOCITY MEASUREMENTS

A COHERENT LIDAR SYSTEM FOR MEASURING THE RANGE AND VELOCITYOF SOLID OBJECTS WILL BE DEVELOPED. THE ILLUMINATION AND LOCAL OSCILLATOR BEAM ARE BOTH DERIVED FROM A FREQUENCY-MODULATED LASER. FOR STATIONARY TARGETS, THIS CAUSES A BEAT SIGNAL RELATED TO THE RANGE-INDUCED TIME DELAYOF THE TARGET SCATTER. FOR MOVING TARGETS, THE RANGE-INDUCED BEAT NOTE APPEARS AT A DOPPLER-SHIFTED POSITION. AN APPROPRIATE MODULATION FORMAT CAN DECOUPLE THE EFFECTS OF RANGE AND VELOCITY; THE METHOD ALLOWS ONE TO DISTINGUISH BETWEEN RECEDING AND ADVANCING TARGETS. THE COMPACTNESS, ALIGNMENT ROBUSTNESS, AND SENSITIVITY ARE ENHANCED BY AN INNOVATIVE TRANSCEIVER AND MIXER SCHEME BASED ON FIBER-OPTIC WAVEGUIDES. FIBER-OPTIC COMPONENTS MINIMIZE SPACE REQUIREMENTS AND INHERENTLY GUARANTEE HIGH MIXING EFFICIENCIES. A SINGLE-MODE TRANSMIT AND RECEIVE APERTURE OPTIMALLY MATCHES THE RECEIVING AND TRANSMITTING DIRECTIVITIES. A BALANCED MIXER SCHEME LIBERATES THE SYSTEMFROM LASER EXCESS NOISE, LEADING TO SHOT-NOISE-LIMITED DETECTION AT LOW FREQUENCIES. ESTIMATES INDICATE EXCELLENT POTENTIAL FOR MEASURING THE RANGE AND RADIAL VELOCITY WITH APRECISION IN EXCESS OF 1 PERCENT AND .003 M/SEC, RESPECTIVELY. A COHERENT LIDAR SYSTEM FOR MEASURING THE RANGE AND VELOCITYOF SOLID OBJECTS WILL BE DEVELOPED. THE ILLUMINATION AND LOCAL OSCILLATOR BEAM ARE BOTH DERIVED FROM A FREQUENCY-MODULATED LASER. FOR STATIONARY TARGETS, THIS CAUSES A BEAT SIGNAL RELATED TO THE RANGE-INDUCED TIME DELAYOF THE TARGET SCATTER. FOR MOVING TARGETS, THE RANGE-INDUCED BEAT NOTE APPEARS AT A DOPPLER-SHIFTED POSITION. AN APPROPRIATE MODULATION FORMAT CAN DECOUPLE THE EFFECTS OF RANGE AND VELOCITY; THE METHOD ALLOWS ONE TO DISTINGUISH BETWEEN RECEDING AND ADVANCING TARGETS. THE COMPACTNESS, ALIGNMENT ROBUSTNESS, AND SENSITIVITY ARE ENHANCED BY AN INNOVATIVE TRANSCEIVER AND MIXER SCHEME BASED ON FIBER-OPTIC WAVEGUIDES. FIBER-OPTIC COMPONENTS MINIMIZE SPACE REQUIREMENTS AND INHERENTLY GUARANTEE HIGH MIXING EFFICIENCIES. A SINGLE-MODE TRANSMIT AND RECEIVE APERTURE OPTIMALLY MATCHES THE RECEIVING AND TRANSMITTING DIRECTIVITIES. A BALANCED MIXER SCHEME LIBERATES THE SYSTEMFROM LASER EXCESS NOISE, LEADING TO SHOT-NOISE-LIMITED DETECTION AT LOW FREQUENCIES. ESTIMATES INDICATE EXCELLENT POTENTIAL FOR MEASURING THE RANGE AND RADIAL VELOCITY WITH APRECISION IN EXCESS OF 1 PERCENT AND .003 M/SEC, RESPECTIVELY.