An evaluation method of snow particle size distribution functions from VTR image for meteorological radar observations

For meteorological radar observations, it is very important to know the size and the type of precipitation particles. In the paper, the authors propose a simple method to evaluate snow particle size distribution functions using a snow particle VTR image, and show their results by means of this method. The image of snow particles recorded by a VTR camera is digitized using a personal computer. To avoid the overlap of particles and to reduce background offset, the authors use subtraction processing between images at different recording times. They obtain projection data of the image in two directions and recognize the position of each snow particle using back projection processing, then measure the size of each snow particle. They apply this method to the VTR tapes that had been recorded at Syowa Station, Antarctica, in April and September 1988