Pulsed blue-green propagation through cloud and fogs
Abstract
Measurements have been made of the temporal and spatial spreading of a blue-green pulse through clouds and fogs as a function of optical thickness and receiver field-of-view (FOV). The fog data were collected between two ground sites, separated by 1 km, at Point Loma, San Diego. The transmisser was a Nd:YAG laser, operating at 10 pps, with a frequency doubler to provide output at 530 nm and a beam expander to decrease the divergence. The cloud data were obtained with a geometry that simulates the satellite-to-earth downlink communication link: an aircraft at 40,000 ft illuminated a 6 km diameter spot on the cloud tips by using a Nd:YAG frequency doubled laser; a second aircraft probed the clouds with meteorological instruments and Knollenberg particle counters; a receiver on the ground pointed upwards with a fixed FOV of 90 deg. Experimental and theoretical results of both studies are compared and presented graphically.
- Publication:
-
In: Clouds - Their formation
- Pub Date:
- 1981
- Bibcode:
- 1981cfop.proc..465M
- Keywords:
-
- Atmospheric Optics;
- Cloud Physics;
- Clouds (Meteorology);
- Fog;
- Light Scattering;
- Laser Applications;
- Optical Thickness;
- Spatial Distribution;
- Temporal Distribution;
- Lasers and Masers