Applicability And Visualization Research Based On ITU-R P.1546 Propagation Model

Following the increasing development of information technology,radio broadcast communication technology is used in various fields such as national defense,navigation systems,the satellite industry and personal mobile communication.However,because of the complexity of the electromagnetic environment in which radio waves propagate,they are susceptible to interference from different factors.Therefore,it is very important to study and analyze the propagation characteristics of radio waves in different propagation environments.Based on the analysis of radio propagation and the comparison of different propagation models,the ITU-R P.1546 propagation model is finally selected for applicability and visualization.ITU-R P.1546 propagation model is a typical semi-empirical and semideterministic model.The model obtains the required field strength value by interpolation or extrapolation of calibration parameters,which is widely used in point-to-face ground services.In order to realize the study of the Web GIS-based modelling and visualization of the ITU-R P.1546 propagation model in Lanzhou,this thesis is an analysis of the prediction method and core algorithm study of the propagation model,simplifying it,removing the calculation process that is not required for the local environment,and using Matlab to modify the correction method mentioned in the proposal,and designing the forecasting of the propagation model.The process takes into account both the computational accuracy and the computational efficiency,so as to reduce the computational effort in the prediction process as much as possible while ensuring the prediction accuracy.As the prediction calculation in the ITU-R P.1546 model requires link elevation data,the highest accuracy SRTM1 elevation data available in China was used to ensure the accuracy of the calculation.In order to analyze the error between the model prediction and the actual one,this thesis takes the data collection for the An Ning and Bai Yin areas of Lanzhou respectively under the same experimental parameters and analyses the two data with the results calculated by Matlab.The suitability of the model in the Lanzhou area is confirmed.The comparison between the model and the conventional Okumura-hata model for propagation prediction shows that the ITU-R P.1546 propagation model has a higher accuracy than the conventional model in Lanzhou area.By correcting for the terrain clearance angle,transmitter clearance angle and receiver antenna height.The mean square error of model loss was reduced by 14.3% in the Anning area and 15.6% in the Silver area.The difference between the correction for the terrain clearance angle and the actual loss is greater when there are high obstacles above the transmitter and receiver paths.Based on the above research,the modified ITU-R P.1546 propagation model is used to simulate the Lanzhou area.In order to show the coverage of the launch station more macroscopically,Web GIS is used to show the simulation results.The GIS Java Script Leaflet library is used to construct the map base map for Web GIS,the calculated predictions are interpolated and calculated by kriging interpolation,the generated layers are overlaid onto the map to realize the coverage predictions,and finally the radio wave propagation model is combined with a Web GIS to visualize this propagation model.This thesis can help to improve the accuracy of the analysis of radio wave propagation prediction,and provide a theoretical basis for rapid propagation prediction in plain areas,and achieve an intuitive and accurate display of propagation prediction,providing a useful reference for local studies in the Lanzhou region of this model.It also hides the complex mathematical calculations and model modelling behind an intuitive interface,making it easier for users to use the model and enhancing their experience.