Measurement And Analysis Of Near-surface Atmospheric Refractivity With Doppler Weather Radar

Atmospheric refractivity is related to temperature, pressure and water vapor, it changes the radar wave propagation paths and phase angle of echo. Therefore, the echo phase angle of a object change can be calculated the changes atmospheric refractivity, and information of water vapor then be obtained, which is useful for diagnose and predict weather.This paper using a S-band Doppler weather radar of Jiangsu weather observation station, and installed an I, Q data synchronization recorder to record the full echo data, that access to echo intensity, radial velocity and radial velocity spectrum width on the basis of three bases according to the original echo, increasing record I, Q signals. Measurement of near-surface atmospheric refractivity with Doppler weather radar and record the original echo of I, Q signal, is able to export target echo phase, then get on the air refractive index of the propagation path of radar.A few fixed targets are selected around Radar station in 30km, got on the path of their refractive index and its changes. Comparative analysis for 15 days of atmospheric refractivity and meteorological data calculation, demonstrating their consistency is very good; In addition, analyses the different weather such as fog, snow, thunderstorm before and after the change of atmosphere refractivity, show that under the non-clear-weather, Doppler radar inversion of atmospheric refractive index can properly reflect the actual weather, relative error of not more than 1%. Therefore, using Doppler weather radar inversion of atmospheric refractive index not only precision and reliable, but also can get the high resolution of atmospheric refractive index distribution, provide reference information for weather analysis.