Coherent Lidar Probe for Volumetric Airwake Measurements

Period of Performance: 01/06/1997 - 01/06/1999

$727K

Phase 2 SBIR

Recipient Firm

Coherent Technologies, Inc.
135 S. Taylor Avenue,
Louisville, CO 80027
Principal Investigator

Abstract

A novel, pulsed, coherent solid state lidar is proposed to acquire space and time resolved images of time varying wind vector fields in localized volumes. In addition to acquiring time resolved images of small scale turbulence patterns in the natural atmosphere, the proposed system can be used to map the time varying flow around and below helicopters or other VTOL aircraft, around buildings, and around moving large vehicles. A novel high bandwidth, dual polarization transmitter waveform is used to extract the line-of-sight velocity at high range resolution (1 to 3 feet) with moderate velocity precision (1 to 2 knots). Achievable updated rates of 1-2 seconds for a scanned volume of order 100x50x50 feet are possible in the near term and should be sufficient to follow wind vector patterns in moderate turbulence. Significantly faster update rates will be possible with smaller volumes. For demonstration purposes the system would have multiple separated scanner units and would be a lidar equivalent of the well-know multi-Doppler radars that can image vector wind fields in 3D within precipitating storm clouds. A development and test program is proposed to demonstrate the technology. It is expected that data post-processing algorithms currently in development will eventually allow retrieval of the vector winds from data collected with a one or two scanner unit. The proposed test program would allow testing and validation of these later concepts