Research Of GPS Spoofing Technology

The importance of GPS in military and civil field is undoubted for its strong support for almost every navigation equipment in daily life and weapon like guided missiles.GPS brings tremendous convenience to human life and it is a firm foundation for information warfare and long-range combat.Meanwhile,the wide application of GPS also brings negative effects to society.The UAV accidents result in casualties and economic loss.GPS spoofing technology is not only a hot spot in military filed,but also an important technology applied in society.Before we discuss GPS spoofing,this paper briefly introduces the formation of GPS system and GPS signal and the production of GPS signal.C/A code is only ranging code for civil GPS device,this paper analyzes the modulation and correlation of it in detail.The principle of GPS positioning is analyzed based on introducing the concept and measurement of pseudorange.The method of calculating user position is proposed and least square method is discussed.Based on the discussion above,transmitting spoofing and generating spoofing is studied.We elaborates the principle of transmitting spoofing and the model of basic design and fixed point spoofing are introduced.We discussed the compensation for negative delay and the simulation of it is proceeded.A method of generating spoofing based on SDR device is proposed and we specified the flow of deceptive-jamming signal generation.Then,an earth rotation correction algorithm of pseudorange is proposed and the calculation of Doppler shift is analyzed.Experimental result shows that this generating spoofing method is highly deceptive and accurate.At last,this paper studies the orientation-inducing model and shift-inducing model of UAV.Orientation-inducing model can change UAV's established direction to the direction we wanted.Shift-inducing model is based on orientation-inducing model and discusses the way of spoofs UAV to a specified location.A calculation of shift vector is proposed for UAV in different conditions.The simulation results verify the feasibility of this model.