Gps Positioning And Interference Technology Research

As the most advanced navigation and positioning system in the world nowadays,GPS is used widely especially on martial aspects,satellite positioning technology is becoming a hot spot.In the war of navigation,usage of GPS has become essential for precise command control and the precision of attacks and armed force deployment and influence the means and effects of the war at its every phase.So research on the technology of the GPS positioning and jamming technology has become the urgent task.In this thesis,algorithm in resolving position and jamming effect of GPS are discussed deeply.There are two purposes of my paper:one is searching for technological measures for wining in the future battlefield;the other is offer a reference for building the navigation and positioning system of our country.This paper is divided into 4 topics and provides a detailed discussion on these topics in chapter 2,3,4,and 5 respectively.Chapter 1 is the preface,which concisely introduces the GPS and the technology of positioning and jamming.The framework of this dissertation is also introduced at the end.Chapter 2 studies the algorithm in resolving position of GPS.Based on the model of resolving position,two new recursive algorithm:Householder transformation method and emendatory Gram-Schmidt method are presented,then with the recursive least squares method for simulation analysis.The results of simulation show that the new algorithms are improving significantly on computing efficiency. Chapter 3 analyzes the mathematical model of GPS receiver,the effect of jamming is studied from the point of view of BER.The BER expressions of different type jamming signal is calculated.The simulation model is built by using MATLAB,through which the simulation result of different jamming type is obtained.The best barrage jamming type is known by simulation.Chapter 4 proposes a new space-based jamming system of GPS,the theoretic project of the jamming system is given.Based on the system,the choice of delay transponders in repeating deception jamming is discussed.The relationship of the delay time and signal transmit rate is known by analysis,then certificated by the simulation.Chapter 5 studies the effect of deception jamming from the point of view of acquisition probability,a mixed jamming method is proposed which can increase the acquisition probability of the fake GPS signal.Then I analyze the effect of GPS jamming on positioning accuracy from the point of SNR.Chapter 6 is the summarization of the dissertation.