The Key Technology Research On Blanketing Jamming Monitoring Of Satellite Navigation System

The satellite navigation system is constantly influenced by the complexelectromagnetic environment during the construction and operation. Therefore, someperformance degradations were caused by elctromagnetic jamming from theenvironment, making electromagnetic jamming an important issue in systemconstruction. Accordingly, the jamming monitoring technology, which is an effectiveamelioration method of elctromagnetic jamming, has been intensively researchedrecently. Especially, jamming monitoring is the foundation of different anti-jammingmethods. Thus, the jamming monitoring technique is of great importance in thestatellite navigation system. Consequently, this paper analysed the characteristics ofclassic jamming and navigation signals based on this background. Moreover, a lowjamming monitoring algortithm with a low false-alarm probility and a lowfalse-dismissal probility was proposed through the analysis of classic blanketingjamming characteristics. Besides, an auto gain control algortithm with high dynamicrange was also proposed. In the end, an monitoring&analysis software of an onlinejamming monitoring system for BeiDou Satellite Navigation System (BDS) wasrealized on the basis of the proposed algorithms. The research achievements weresuccessfully applied in a significant and objective-targeted engineering project.The details of this paper are as follows.Firstly, the characteristics of classic blanketing jamming in satellite navigationsystem were analyzed and the characteristic parameters were extracted. A pulsejamming monitoring algorithm using adaptive threshold judgement of pulse width anda continuous carrier jamming monitoring algorithm using dual threshold judemengtswere propsed according to the characteristic analysis. Combining these two methods,we can acquire both low false-alarm probility and low false-dismissal probility in thejudgement of blanket jamming, realizing the low false-alarm probility and lowfalse-dismissal probility jamming monitoring.Secondly, aiming at the need of high dynamic signal range in jammingmonitoting, this paper proposed an AGC algorithm of high-dynamic-range basedamplitude-limiting-ratio. Comparing to the disadvantges of traditional AGC inGaussian jamming pattern and single carrier jamming pattern, this algorithm canadapt to different jamming patterns and fully utilize the effective bit in single carrier jamming. Thus it could achieve the minimum SNR loss after signal quantization,assuring the stable reception performance in differnet jamming patterns.Thirdly, this paper developed an monitoring&analysis softwarein BDS basedon proposed jamming monitoring algorithms. This software, which is capable ofonline monitoring of jamming signal, offline precise analysis and self simulation, wasimplemented with three modes, including online analysis mode for real-timeapplications, offline analysis mode for high-precision applications and simulationanalysis mode for software self-check application. A thorough test of this platformwas performed to verifiy the proposed algorithms and this software on an BDS onlinejamming monitoring platform. The test results proved the effectivity and the excellentperformance of blanketing jamming monitoring algorithms and theamplitude-limiting-ratio based AGC algorithm. Besides, it could provide strongsupport for the construction of BDS jamming monitoring system, showing promisingprospects in its application.