A Dense Network for Rapid Measurement of Rainfall Rate

Studies of the effects of rain on propagation at centimeter and millimeter wavelength have shown that attenuation by rain becomes more severe as the wavelength decreases. 1-5 The attenuation becomes objectionable at a wavelength of about 5 cm and increases rapidly. Information on the temporal and spatial characteristics of a rainfall at the surface of the earth is scant and further knowledge is needed to permit design of systems for the radio frequency bands above 10 GHz. An experiment has been designed to obtain statistical data on both the temporal and spatial distribution of heavy rainfall in both time and space. The rainfall data are collected from a network consisting of approximately one hundred gauges about 1.34 km from each other and covering an area of 130 square km, as shown in Fig. 1.* The dot within each grid indicates the physical location of a rain gauge mounted at the top of a telephone pole, approximately 7.6 m above * Part of this material was presented to the Union de Radio Scientifique Internationale Commission 2 in Ottawa, Canada (May 1967). t i t has become clear during the course of our experiments that an intergauge spacing of 1.34 km is too large to resolve some of the rain cells. 1745