同步式GPS欺骗干扰信号生成技术研究与设计

出于对"低、慢、小"无人机进行导航定位诱骗的实际需求，在实验室原有的异步生成式GPS欺骗干扰源的基础上，研制了一种小型化的同步生成式GPS欺骗干扰源。首先，在异步生成式GPS欺骗干扰源射频信号模型的基础上，考虑到干扰源信号处理延时、欺骗信号的传播延时、无人机上目标接收机所接收真实卫星信号状态以及无人机运动模型，建立了对同步欺骗信号仿真时间和状态参数进行精确计算的数学模型。其次，通过本地授时型接收机提供驯服后的基准时钟和秒脉冲（1PPS）信号，实现欺骗干扰信号与真实卫星信号系统时的同步，并通过高阶直接数字频率合成（DDS）技术精确控制信号参数、保证欺骗信号到达目标接收机接收天线相位中心时与真实信号的相位状态在成功诱骗所允许的误差范围之内。最后，通过商用接收机和无人机进行了实验验证，在无人机上目标接收机正常跟踪真实卫星信号的前提下，开启同步生成式GPS欺骗干扰源发射欺骗信号，能够使目标接收机逐渐偏离正常定位测速结果而产生受控的定位测速结果。结果验证了同步信号模型和所设计同步信号生成电路的正确性，且表明同步生成式GPS欺骗干扰源能够实现对商用接收机和无人机导航定位的诱骗。 

Research and design of synchronous GPS spoofing signal generation technology

In order to meet the actual requirements of navigation spoofing of "low, slow, small" UAV, a miniaturized synchronous GPS spoofer has been developed based on our asynchronous GPS generator spoofer. Firstly, based on asynchronous GPS generator spoofer RF signal model, considering the spoofer signal processing delay, the spoofing signal propagation delay, the status of the authentic satellite signal received by the UAV receiver, and the dynamic model of the UAV, established the mathematical model to accurately calculate the simulation time and state parameters of the synchronous spoofing signal. Secondly, a local timing receiver is employed to provide the disciplined reference clock and 1 pulse per second (1PPS) signal to synchronize the spoofing signal with the authentic system time, and high-order direct digital synthesis(DDS) technology is applied to accurately control the signal parameters and ensure that the difference between the spoofing signal and the authentic signal is within the tolerances allowed for successful spoofing when the spoofing signal reaches the phase center of the receiving antenna of the target receiver. Finally, the test results using a popular commercial UAV and a commercial receiver are presented. When the UAV receiver tracks the authentic satellite signal, the synchronous GPS spoofer begins to transmit the spoofing signal, which gradually deviates the target receiver from its normal measurements and makes it output the position and velocity results under control. The results verify the established synchronous signal model, the designed synchronous signal generation circuit, and indicate the synchronous GPS spoofer can achieve navigation spoofing of commercial UAV and commercial receiver.