Research On ITU-R Radiowave Propagation Model And Software Design For Visual Pediction

By the study of prediction process and key algorithms of ITU-R P.1546 propagation model and ITU-R P.533 propagation model,this paper combined radiowave propagation model with Geographic Information System(GIS),implemented the software of radiowave propagation prediction system,which can use propagation model for predicting the field strength of communication circuit or coverage,and visualizing the predicted values on the GIS platform.The main research work was as follows:(1)This paper made a deep study in ITU-R P.1546 proposal and ITU-R P.533 proposal,streamlined the predicting process,and proposed The implementation design of propagation prediction for the two models.The design process considered the predictive efficiency of the system.In order to ensure the accuracy of the prediction,the computation of the prediction process should be reduced as much as possible.(2)This paper operated the secondary development on the Baidu Map API platform,combining Baidu Map with Digital Elevation Model(DEM),which is widely used now,constructed the Geographic Information System(GIS)needed for the prediction and realization of radio propagation model.(3)This paper implemented a software system for field strength prediction based on propagation model and GIS technology.Based on ITU-R P.1546 model,the prediction functions of the prediction system in VHF and UHF bands,including point-to-point,transmission coverage and monitoring coverage were implemented.The predicted values of the model are represented on the GIS platform as overlay forecast maps directly overlaid with gradient colors,the prediction diagram can directly show the influence of topographic factors on radio wave propagation.Based on ITU-R P.533 model,the prediction of skywave propagation was implemented,the prediction process is divided into two steps,the first step is the prediction of ionospheric parameters,which can make a 24-hour circuit MUF prediction for a communication circuit on a specified date,the predicted results will be plotted as a graph of MUF over time.The second step is the prediction of point-to-point receiving field strength,the results show the details of every possible propagation pattern on the communication circuit.(4)The prediction test of the software was completed.ITU-R P.1546 model shows the effect of topographic relief on radio wave propagation.The results of the ITU-R P.533 model agree with the variation law of ionospheric parameters,when compared with the literature results,the two methods have good consistency.This paper provided a new idea for the low cost and high efficiency development of radio wave propagation prediction system.