AIRBORNE COHERENT LIDAR SYSTEM FOR THE DETECTION OF CLEAR AIR TURBULENCE

CLEAR AIR TURBULENCE (CAT), WHICH CAN CONTAIN DIFFERENTIAL WIND VELOCITIES OF 100'S OF METERS PER SECOND, ARE A SEVERE DANGER TO AIRCRAFT WHICH ENCOUNTER THEM WITHOUT WARNING. WE DESCRIBE AN EYE-SAFE LIDAR SYSTEM DESIGNED TO PROVIDE 10 SECONDS OF WARNING TO AN AIRCRAFT TRAVELING AT 400 KNOTS. THE SENSOR DETECTS THE PRESENCE OF AIR TURBULENCE BY MEASURING THE VARIANCE IN THE DOPPLER-SHIFTED BACKSCATTER OFF AEROSOLS IN THE VICINITY OF THE FLIGHT PATH. EXAMINING THE VARIANCE OF THE DOPPLER SPECTRUM ALLOWS FOR THE DETECTION OF TURBULENCE IN REAL-TIME. THE PHASE I EFFORT WILL SPECIFICALLY DEFINE THE RECOMMENDED IMPLEMENTATION, PREDICTED PERFORMANCE AND PRACTICAL UTILITY OF THE PROPOSED TECHNOLOGY FOR THE DETECTION AND AVOIDANCE OF CLEAR AIR TURBULENCE HAZARDS. IN SUPPORT OF THIS GOAL, THE PHASE I ACTIVITY WILL (A) DEFINE THE PERFORMANCE SPECS FOR EACH OF THE CRITICAL COMPONENTS/SUBASSEMBLIES IN THE SYSTEM, (B) INCLUDE A PRELIMINARY DESIGN OF THE MID-IR SOLID-STATE LIDAR TRANSCEIVER AND REAL-TIME SIGNAL/DATA PROCESSOR, AND (C) DEVELOP STRATEGIES FOR OPTIMAL UTILIZATION OF CAT DETECTION DATA FOR AIRBORNE PLATFORMS. APPLICATIONS OF THE PROPOSED RESEARCH RELATE TO TWO AREAS: (1) THE FURTHER DEVELOPMENT OF MID-INFRARED SOLID-STATE LASER TECHNOLOGY FOR SCIENTIFIC STUDIES, AND (2) USE OF THE REMOTE SENSING TECHNOLOGY IN ATMOSPHERIC RESEARCH, COMMERCIAL AVIATION, AND POLLUTION/TOXIC GAS MONITORING.