Transit Time Lidar Measurement of Near-Surface Winds in the Atmosphere.
Abstract
This report deals with an improved model of a transit time laser radar. The technique measures a backscatter signal from atmospheric aerosols from two sample volumes a known distance apart in the atmosphere. These two signals are cross-correlated to obtain the time of flight of aerosol inhomogeneities as they move from one volume to another. Once the time of flight is calculated, the windspeed can be obtained since the distance between sample volumes is known. This model utilizes a copper vapor laser as the transmitter source. Crosswind data were successfully obtained in the unperturbed atmosphere under very clear, and thus difficult, conditions with horizontal visibility of 130 km. Results of the experiments showed that even under these conditions the variability of the aerosol concentration was high enough to permit a correlation that generated a reliable wind measurement at least once a minute. Transit time lidar wind measurements agreed within 15 percent of values simultaneously recorded with an anemometer. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1979
- Accession Number
- ADA071355
Entities
People
- R. Rodriguez
- T. L. Barber
Organizations
- Atmospheric Sciences Laboratory