Study Of The Influence Of Weather Radar From Electromagnetic Radiation On Environment

On the basis of radiation power density calculation model recommended by the state and power density prediction model applied in the environmental effect assessment, a more reasonable and accurate computational model of weather radar power density was derivated by introducing direction function of transmit antennas and considering the loss of electromagnetic wave in the emission and transmission. The computational model was verified effective by measuring actually S band, C band and X band weather radar station. In the far field radar antenna, the measured value can be instead the calculation value, and it could protect fully the public by irradiation dose below the limit of national standard.Through the establishment of weather radar power density calculation model, calculation and analysis to the S band, C band and X band weather radar power density, founding that the power density decreased with increasing horizontal distance predicted points and antenna. The radar antenna is a greater impact on the surrounding electromagnetic environment in RHI scan mode, the power density values higher than the PPI mode 1 orders of magnitude, and higher than the VOL model about 2 orders of magnitude. Power density strength of three kinds of scanning modes: VOL scan mode <PPI scan mode <RHI scan mode. Power density strength of radar antenna side lobe resulting: the distal side lobe < the first side lobe. Under the peak transmit power of radar, 6min power density average value around the antenna is 1000 times more than the mean average transmit power. In the vertical direction, the more recent distance of radar antenna, the greater electromagnetic radiation intensity and the higher the serious limit. In order to show the distribution of the electromagnetic field around the antenna directly and clearly, drawing the antenna near certain domain power density isoline map by combining the theory calculated results and surfer software.Based on S band, C band and X band weather radar power density were measured, the results showed that X band weather radar power density can meet the national standard limit, S band and C band had a part of monitoring points exceeded the national standard limit requirements in RHI scan mode. With comparing the values of theoretical calculation and analysis of the actual monitoring data, founding that power density of theoretical calculation and measured values decreasing with increasing distance from the antenna. In the far field of the antenna, the theoretical calculation value of relative error is smaller and the measured value can be instead of the theoretical value; in the near field of radar antenna, the error of theoretical calculation is relatively larger than the measured, the power density of the near-field region should be based on measured value. It is feasible for prediction and analysis of electromagnetic environment around S band, C band and X band weather radar with the calculation model built in this thesis. The calculation model has theoretical and practical significance for evaluation of environmental effects of electromagnetic radiation of weather radar.