The Windvan pulsed CO2 Doppler lidar wide-area wind sensor
Abstract
Wind sensing using a Doppler lidar is achieved by sensing the Doppler content of narrow frequency laser light backscattered by the ambient atmospheric aerosols. The derived radial wind components along several directions are used to generate wind vectors, typically using the Velocity Azimuth Display (VAD) method described below. Range resolved information is obtained by range gating the continuous scattered return. For a CO2 laser (10.6 mu) the Doppler velocity scaling factor is 188 kHz/ms(exp -1). In the VAD scan method the zenith angle of the pointing direction is fixed and its azimuth is continuously varied through 2 pi. A spatially uniform wind field at a particular altitude yields a sinusoidal variation of the radial component vs. azimuth. The amplitude, phase and dc component of this sinusoid yield the horizontal wind speed, direction and vertical component of the wind respectively. In a nonuniform wind field the Fourier components of the variation yields the required information.
- Publication:
-
In NASA
- Pub Date:
- July 1990
- Bibcode:
- 1990awsd.nasa..835L
- Keywords:
-
- Carbon Dioxide Lasers;
- Doppler Radar;
- Meteorological Radar;
- Optical Radar;
- Wind (Meteorology);
- Wind Measurement;
- Aerosols;
- Azimuth;
- Backscattering;
- Detection;
- Frequencies;
- Infrared Radar;
- Laser Outputs;
- Light Beams;
- Scanners;
- Sine Waves;
- Velocity Distribution;
- Wind Velocity;
- Zenith;
- Lasers and Masers