title: Measurement of rain parameters by optical scintillation.
abstract: We describe a technique for measuring path-averaged rain parameters by analyzing the rainfall-induced scintillations of a laser beam. From the time-lagged covariance function of two vertically spaced line detectors, we determine the average rainfall rate and drop-size distribution along the optical path. This technique requires no prior assumption of the form of the drop-size distribution. Sample measurements on a 140-m path confirm that the path-averaged drop-size distribution of a steady rain follows a Marshall-Palmer distribution. The optically measured path-averaged rain rate also shows good agreement with conventional tipping-bucket rain-gauge data.
authors.forename: T I
authors.initials: TI
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Lerfald
authors.forename: R S
authors.initials: RS
authors.lastname: Lawrence
authors.forename: S F
authors.initials: SF
authors.lastname: Clifford