In Situ Lidar for Cloud and Aerosol Radiation Science

SPEC, Inc.

Boulder, CO
 

This research introduces a new technique called in situ cloud lidar, which can measure extinction in liquid clouds with sampling volumes of millions of cubic meters.

• Retrieval simulations are performed using a neural network trained on three parameters fit to the time series of each detector to predict 1) the extinction at four volume-averaging scales, 2) the cloud geometric thickness, and 3) the optical depth at four averaging scales.
• A comparison of extinction coefficients calculated using in situ hot-wire and particle probes, and the in situ lidar, showed excellent correlation.
• The fact that the extinction measurements are well correlated suggests that the in situ lidar is capable of making reliable measurements of volumetric extinction coefficient.

• The lidar is not currently suitable as a commercial product. However, after utilization in NASA or other field programs, analysis of collected data and publication of results, the lidar could easily be configured and sold as a commercial product.
• After more data analysis, the concept put forth as a ground-based device for measuring cloud boundaries and visibility at uncontrolled airports could be developed as a commercial product.

• The lidar can be readily adapted for use in NASA research programs. However, if it is installed on an aircraft other than the Learjet, the aircraft will have to be fitted with a suitable optical flat for the laser.
• The up and down detectors will also have to be installed in a pressurized, temperature-controlled environment and have unrestricted views through optical flats.
• Data collected in stratus clouds and comparison with particle probes establishes the technical feasibility of the in situ lidar to measure volumetric extinction coefficient.

Return to NASA SBIR Success Listings 

Curator: SBIR Support                8/23/05