Abstract
A method for calculating droplet-size distribution in atmospheric clouds is presented, based on measurement of laser backscattering and multiple scattering from water clouds. The lidar uses a Nd:YAG laser that emits short pulses at a moderate repetition rate. The backscattering, which is composed mainly of single scattering, is measured with a detector pointing along the laser beam. The multiple scattering, which is mainly double scattering, is measured with a second detector, pointing at a specified angle to the laser beam. The domain of scattering angles that contribute to the double-scattering signal increases monotonically as the pulse penetrates the cloud. The water droplets within the probed volume are assumed to have a constant size distribution. Hence, from the double-scattering-measured signal as a function of penetration depth within the cloud, the double-scattering phase function of the scattering volume is derived. Inverting the phase function results in a cloud-droplet-size distribution in the form of a log-normal function.
Original language | English |
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Pages (from-to) | 1569-1578 |
Number of pages | 10 |
Journal | Applied Optics |
Volume | 34 |
Issue number | 9 |
DOIs | |
State | Published - Mar 1995 |
Keywords
- Aerosol
- Clouds
- Lidar
- Multiple scattering
- Scattering