IMPROVEMENT OF RANGE OF COHERENT LASER RADAR 3-D IMAGING SYSTEM

A NEED EXISTS FOR HIGH SPEED, PRECISE, AND LONG-RANGE IMAGING SENSORS FOR APPLICATIONS TO ROBOTICS, TELEROBOTICS, ASSEMBLY, AND ALIGNMENT OF LARGE SPACE STRUCTURES. PRECISION 3-D RANGE IMAGING WITH UNAMBIGUOUS RANGE DETERMINATION HAS BEEN DEMONSTRATED WITH A SCANNING FMCW COHERENT LASER RADAR (CLR) USING FREQUENCY MODULATED LASER DIODES AND HETERODYNE DETECTION. HOWEVER, THE MAXIMUM RANGE OF THE CLR IS CURRENTLY LIMITED BY THE COHERENCE LENGTH OF THE LASER DIODE TO LESS THAN FIVE METERS. IT IS THE INTENT OF THE PROPOSED PHASE I EFFORT TO IMPLEMENT AND DEMONSTRATE AN IMPROVED MAXIMUM RANGE OF 100 METERS OR MORE.THE IMPROVEMENT IS POSSIBLE BY NARROWING THE LINEWIDTH OF THE LASER SOURCE WITH ELECTRONIC FEEDBACK, THEREBY INCREASING THE COHERENCE LENGTH. THE LINE-NARROWING TECHNIQUE HAS BEEN DEMONSTRATED IN THE LABORATORY BUT HAS NOT BEEN CONFIRMED WITH A CLR MEASUREMENT. SUCCESSFUL COMPLETION OF PHASE I WILL STIMULATE INTEREST IN LONGER RANGE APPLICATIONS TO MACHINE VISION, AUTOMATION, AND TELEROBOTICS. AN IDEAL PHASE II FOLLOW-ON WILL BE TO SELECT A SIGNIFICANT LONG-RANGE APPLICATION AND TO DEVELOP A PROTOTYPE CLR TO MEET ITS REQUIREMENTS.