Aug 14, 1996

Multi-Agency Mission Uses Laser to Measure Winds






August 15, 1996


During the month of July, the Global Hydrology and Climate Center and partners successfully demonstrated the ability to achieve consistent and accurate atmospheric wind measurements in a series of research aircraft flights using the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS). Not only did the study provide data to better understand the meteorological processes at work during the experiment, this project is expected to assist in the design of a satellite to measure global winds from space. The wind sensor, a coherent Doppler Laser Radar (Lidar), uses pulses of laser light to measure winds from a distance. It does this by observing frequency shifts of the backscattered light that result from the motion of the air. Over the course of 17 flights on the NASA DC-8, the sensor took wind measurements in Washington, Alaska, Texas and California. Measurements of low-level winds, land-sea breeze circulation, structure of a mid-latitude jet stream, and wind structure around a variety of cloud types were conducted. The researchers also performed simulations of the proposed satellite Doppler wind lidar concept. Wind velocity accuracies were observed to be roughly 1 meter per second or better. Additionally, the experiment gathered information on the operational capabilities of the lidar's and the signal processor's performance under less than ideal aircraft environmental conditions such as atmospheric turbulence, various engine thrust settings, and high and low cabin temperatures.

MACAWS has been jointly developed and was operated by the atmospheric lidar remote sensing groups of Marshall's Global Hydrology and Climate Center and the Astrionics Laboratory, NOAA's Environmental Technology Laboratory, and the Jet Propulsion Laboratory.