Abstract

Since the first remote wind measurements in 1967, coherent Doppler lidar has become established as a unique tool for atmospheric research. Remote sensing of the two-dimensional horizontal wind field with airborne coherent Doppler lidar was demonstrated in 1981 using a low-energy scanning CO₂ lidar.¹ The scanner and operations control system were subsequently improved to enable wind field measurements at multiple vertical levels, and the system was reflown in 1984.² Subsequent advances in coherent CO₂ laser technology resulted in the development of a frequency-stable, high energy-per-pulse transmitter (~1 J) which was delivered to the National Oceanic and Atmospheric Administration (NOAA) and incorporated into an existing portable ground-based lidar system.³ Thus the possibility arose for the cooperative development of an airborne system with dramatically improved performance, hence greater scientific applications, owing to lower backscatter sensitivity and broader spatial coverage. In 1992 the lidar atmospheric remote sensing groups of the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC), NOAA Environmental Technology Laboratory (ETL), and Jet Propulsion Laboratory (JPL) jointly developed MACAWS, the Multicenter Airborne Coherent Atmospheric Wind Sensor. Existing components were used when possible to minimize programmatic costs. The high-energy laser transmitter is borrowed from the NOAA windvan lidar.³ The ruggedized optical table assembly is borrowed in part from an airborne backscatter lidar developed and flown by JPL. The scanner, telescope and other components are borrowed from a previous airborne Doppler lidar system which was limited in performance primarily to high-backscatter boundary layer features.^1,2 Some hardware modifications were required to ensure flight safety, reliability, and compatibility with the aircraft environment.

© 1997 Optical Society of America