A NEW, HIGH SENSITIVITY LASER HYGROMETER

THERE EXISTS NO RELIABLE, PRACTICAL MEANS OF ACCURATELY MEASURING LOW ABSOLUTE HUMIDITIES, PARTICULARLY IF REASONABLE RESPONSE TIMES ARE ALSO REQUIRED. THIS INSTRUMENTATION PROBLEM IMPACTS AIRBORNE AND BALLOON MEASUREMENTS OF TROPOSPHERIC AND STRATOSPHERIC PHYSICAL PROPERTIES, AIRBORNE RESEARCH ON CLOUD CHARACTERISTICS, AND ROUTINE MONITORING IN POLAR REGIONS. ANALYSIS OF ATMOSPHERIC INFRARED ABSORPTION SPECTRA AND RECENT DEVELOPMENTS IN INFRARED LASER TECHNOLOGY, COUPLED WITH THE PRINCIPAL INVESTIGATOR'S EXPERIENCE WITH INFRARED HYDROMETERS, HAS LEAD TO THE DEVELOPMENT OF A NEW AND INNOVATIVE LASER HYGROMETER CONCEPT. THE PROPOSED NEW LASERHYGROMETER OFFERS AN OUTSTANDING COMBINATION OF ACCURACY, SENSITIVITY, AND RESPONSE SPEED, COUPLED WITH HIGH RELIABILITY AND REPEATABILITY IN HARSH ENVIRONMENTS, NON-CRYOGENIC OPERATION, COMPACT SIZE, LOW POWER CONSUMPTION, AND MODEST COST. THE PHASE I RESEARCH OBJECTIVES INCLUDE DESIGN AND CONSTRUCTION OF A PROOF-OF-CONCEPT LASER HYGROMETER, VERIFICATION OF ITS PRINCIPAL OF OPERATION AND RESPONSE FUNCTION, PLUS RESEARCH ON A PHASE II HYGROMETER DESIGN AND PHASE II WORK PLAN. IN PHASE II THE LASER HYGROMETER WILL BE TESTED ON AN NCAR (NATIONAL CENTER FOR ATMOSPHERIC RESEARCH) AIRCRAFT, IN COORDINATION WITH NCAR SCIENTIFIC STAFF. A SUCCESSFUL PHASE II RESEARCH AND DEVELOPMENT EFFORT WILL RESULT IN AN ACCURATE, RELIABLE, NON-CRYOGENIC HYGROMETER WITH SENSITIVITY GREATER THAN 0.1 PPMV AND RESPONSE SPEED GREATER THAN 10 HZ.