Research And Simulation On The Ambiguity Function Theory Of Radar Signal

The radar extracts useful information from the echoes by receiving, inspection and processing. Among them, the selection and design of the radar signal waveform has a very important role, it has a direct impact on the choice of the form of radar transmitters, signal processing, radar range, interference, anti-intercepted so many important issues. Therefore, in order to select the appropriate use of the specific form of a radar signal, in the design of the radar system before it is essential to examine the performance of various radar signals. Ambiguity function fully reflects the radar signal precision and resolution in the two-dimensional: distance and speed. Therefore, the radar signal theory of ambiguity function is a very important significance for the optimal radar waveform design.The development of electronic technology has preferred higher and higher requests for modern radar system in many aspects, including acceptance range, resolution, measuring accuracy, electronic counter- measures and so on. Ambiguity function provides the basis for a systematic search for the optimal waveform for a particular modern radar application. It can be taken as measure of the radar system ability to distinguish similar waveforms at the receiver that differ in time of arrival and frequency shift .The ambiguity function can be taken also as measure of how accurately and apparently the range and velocity of a single target can be estimated, and how reliably two targets can be resolved in terms of these parameters. Ambiguity function, the radar receiver output signal of the complex envelope described as a function of radial velocity and distance radar target, it can provide resolution, measurement accuracy, clutter suppression and other important information.Performance methods of simulation study of radar signals have many advantages: First, the simulation will have the flexibility to choose and change the parameters, without changing hardware and software. Second, through the radar signal simulation, the designer can change the parameters to assess the impact of these parameters on the radar system. Thirdly, the key parameters in the simulation study and technology, can save a lot of man-power, material and financial resources; and the flexibility and high repeatability and ultimately achieve cost savings development, shorten their development cycle.This paper based on the waveforms design consideration, begins from the known several kind of radars transmitting signals, infers the different mathematical model of radar ambiguity function, and draws the ambiguity plot, analyzes the signal characteristic. In accordance with the requirements of radar systems (resolution, accuracy, interference etc.) we conducted a linear FM radar simulation experiments designed to assess the practical value of the radar signal. We mainly used Matlab to model and validate every module's functions, and made a better simulation results. Simulation results show that the ambiguity function fully reflect the radar signal in the distance, and speed of measurement accuracy and resolution capabilities. To the environmental conditions in the target set, ambiguity function can be designed by the designer to select an appropriate signal.