A DODE LASER BASED AEROSOL RANGER

THE REMOTE MEASUREMENT OF ATMOSPHERIC AEROSOLS NOW REQUIRES THE USE OF A HIGH POWER PULSED LASER, WHICH IS COSTLY AND UNRELIABLE. A FAR PREFERABLE SOURCE FROM THE USER'S POINT OF VIEW WOULD BE A GALLIUM ARSENIDE LASER DIODE THAT IS SMALL, INEXPENSIVE, EFFICIENT, AND RELIABLE. HOWEVER, DIODELASERS CANNOT SUPPLY THE HIGH PEAK POWERS REQUIRED BY THE AVAILABLE DETECTION TECHNIQUES. THE CONCEPT OF A CONTINUOUSWAVE (CW) REMOTE DETECTION TECHNIQUE THAT WOULD PROVIDE A PERFORMANCE COMPETITIVE WITH THE PULSED APPROACHES HAS BEEN DEVELOPED. BECAUSE THIS APPROACH MAKES POSSIBLE THE USE OF SEMICONDUCTOR LASERS INSTEAD OF LARGE PULSED LASERS, REMOTE SENSING MAY BE TRANSFORMED INTO A COMMERCIALLY VIABLE FIELD. IF THE PROJECT IS SUCCESSFUL IN AEROSOL DETECTION, THE APPROACH CAN ALSO BE APPLIED IN DIFFERENTIAL ABSORPTION LIDAR OR DIFFERENTIAL SCATTERING CONFIGURATIONS TO DETECT TRACE GASES AND AIRBORNE SALTS AND METALS. PHASE I OF THIS PROJECT, INCLUDES BUILDING A STABILIZED DIODE LASER SOURCE, MEASURING ITS PROPERTIES, AND CALCULATING ITS PERFORMANCE INA CW AEROSOL MEASUREMENT SYSTEM. A PROTOTYPE SYSTEM IS TO BE BUILT IN PHASE II, WITH PERFORMANCE DATA TO BE OBTAINED IN FIELD TESTS.