Study On The Methods Of BPM Time Service Signal Monitor

Radio time service includes long wave service, short wave service,low-frequency time-code time service and satellite time service and so on. Theprecision of shortwave time service is milliseconds magnitude. Although the timingaccuracy isn’t high, short wave service is widely applied in the world with its uniqueadvantages. It plays an important role in the national economy, defense scientificresearch as well as scientific research.It has become an indispensable part of technicalbasic work in our country, and so the quality of the timing signal must be guaranted.However, there isn’t a complete system to monitor the performance of the BPM timeservice signal. Therefore, it is very necessary to do this work.In this paper, a special system for monitoring the integrlity and quality of BPMtime service signal is build up based on the short wave receiver of WR-G313. Thispaper focuses on this system and mainly discusses in the following aspects;(1) Analysis of the transmission mode of skywave and groundwave, thepropagated error of BPM time service signal is studied, the propagation loss ofskywave and groundwave is simulated, this can assist people to select a appropriatefrequency point to receive short wave time signal.(2) Design the monitor scheme, The real time monitor’ method is designed tomonitor on four frequency points for the WR-G313receiver only has one singlechannel. This paper mainly studied data acquisition of the receiver, cycle monitoringof four frequency points of BPM and the method of monitoring data processing.(3) Realize of the monitor software scheme. The designed software included themodule of setting parameters, data acquisition module, data display module and datastorage module. BPM monitor software is realized based onLabwindows/CVI2012,this software can collects raw data and monitors modulationdepth and power level of BPM’s four frequency point in real-time.Moreover,it candisplay and store the analyzed signal automatically and graphically. The software hasa good man-computer interface and simple operation, flexible functionality.(4) Test of the monitor system. A test platform is constructed, the test resultsindicate that the monitor system to test the function and performance of the designedmonitor system. The results of test demonstrate the monitoring system has a functionof monitor the quilaty and Integrity of BPM time service signal. The correctness of collecting data compare to software of receiver is verified.The BPM monitor system designed in this paper is potable，simple to operate,clearly displaying and automatic save data. That completed unmanned on duty andavoid artificial record data. It is a new automatic monitoring system which can satisfymonitor requirement of BPM time service signal and can be applied to monitor thequality of BPM time service signal in both near field and far field.