The Microwave Communication Link Measures Precipitation

This article is supported by the Natural Science Foundation of China(No.41605122).With the development of fifth-generation wireless communication technology,the millimeter-wave radio frequency band will be an important part of the research of 5G communication networks,and microwave communication links have been widely distributed around the world.The paper starts with the ITU-R model and uses the microwave rain attenuation characteristics and a microwave link rainfall attenuation inversion model by Laws-Parsons raindrop spectrum model in the proposal.The microwave signal attenuation can be used as a complement to traditional rainfall measurements,thus further improving the accuracy of traditional rainfall observations.It is of great significance to realize forecasting of precipitation and other meteorological elements.The main contents of this paper are as follows:(1)In the fall of 2016,a signal link with a path of approximately 0.08 km and a frequency band of 25 GHz was established at the Institute of Atmospheric Physics,Chinese Academy of Sciences for the first time with completing observation tests of temperature,humidity,and rainfall;In the autumn of 2017,an experiment was carried out to measure the rainfall at using a line-of-sight analog microwave link of 23 GHz,25 GHz,28 GHz,38 GHz at length of approximately 0.7 km.The test mainly monitored the attenuation of microwave signals in different frequency bands under different rainfall intensity.The study found that: When rainfall occurs,microwave signal attenuation is significant,and the greater the rain intensity,the stronger the microwave signal attenuation.Using the rain attenuation model to invert the rain intensity indicates that the rain intensity of the microwave link inversion has a good correlation with the traditional measured rainfall intensity.(2)Rainfall intensity inversion was calculated on a commercial(81.625 GHz /71.625 GHz)data jointly tested by Ericsson,Swedish Hi3 G and the Swedish Meteorological and Hydrology Institute(SMHI)at length of 3.0 km.The study find that : Where the link length is 3.0 km,the commercial microwave link inversion rainfall intensity is closer to the actual measured rainfall intensity.Compared with analog microwave links,commercial microwave link inversion rainfall intensity has a better correlation with traditional measurement rainfall intensity.Then,we will try to analyze the causes of the errors in the experiment improves the accuracy of detection method.