LIDAR MAPPING OF CLOUD TOPS AND CLOUD TOP WINDS

GROUND-BASED AND AIRBORNE PROGRAMS HAVE DEMONSTRATED THE POTENTIAL OF DOPPLER LIDARS TO MEASURE WINDS IN THE CLOUD-FREE REGIONS OF THE ATMOSPHERE. TO PROVIDE FULL TROPOSPHERIC WIND PROFILES FROM SPACE WOULD REQUIRE A VERY POWERFUL (10-20 J) AND A HEAVY LIDAR SYSTEM. ALTHOUGH A MORE MODEST SYSTEM WOULD BE LIMITED TO THE HIGHER BACKSCATTER REGIONS OF THE ATMOSPHERE (I.E., CLOUD TOPS, THIN CIRRUS LAYERS, THE PBL, DUST CLOUDS, ETC.) THE GLOBAL COVERAGE MAY STILL REPRESENT A SIGNIFICANT CONTRIBUTION TO IMPROVING WEATHER FORECAST AND DIAGNOSTIC SKILLS. USING OUR EXPERIENCE AND COMPUTER MODELS DEVELOPED IN A FEASIBILITY STUDY FOR A LARGE CO2 WIND SOUNDER, WE PROPOSE TO CONDUCT A PHASE I STUDY FOR A LOW POWER LIDAR SYSTEM TO BE USED TO MAP CLOUD TOPS AND MEASURE CLOUD TOP WINDS. THIS STUDY WILL RESULT IN: (1) SPECIFICATION OF PRELIMINARY SAMPLING REQUIREMENTS TO ACHIEVE VARIOUS LEVELS OF PERFORMANCE (LINE-OF-SIGHT ACCURACY, MEASUREMENT REPRESENTIVENESS); (2) A BASELINE DESIGN/CONFIGURATION (WAVELENGTH, POWER, PRF, SCAN ANGLE) OF A HIGH B SPACE-BASED DOPPLER LIDAR CLOUD TOP MAPPER/WIND MEASURING SYSTEM; AND (3) SPECIFICATION OF THE MISSION OBJECTIVES FOR A PHASE II AIRBORNE OBSERVATION PROGRAM NEEDED TO OPTIMIZE THE DESIGN OF THE HIGH B SENSOR. THE MOST LIKELY BENEFIT OF THE DEVELOMENT OF A HIGH B SPACE-BASED DOPPLER LIDAR WIND SOUNDER WOULD BE IMPROVED WEATHER FORECASTING IN SUPPORT OF MILITARY OPERATIONS. DOD IS THE MOST PROBABLE AGENCY INTERESTED IN THIS CAPABILITY.