Design Of Signal And Research Of Information Extraction To High Resolution Radar

It is becoming trends of modem Radar technology, which are ultra-wide band, high resolution, low probability of interception, intelligent, according to the points of high tech local war happened last several decades. Especially with increasing emergence of indetectable, higher defending-ability is required more. It is very important to implement the research of Radar signal designing and data processing method in order to improve the sensitivity and detecting ability of Radar system and to provide practical waveform and signal processing technology for future advanced Radar. Wavelets analysis is a promising approach to process ultra-wide band Radar signal. It has tremendous potential to combine wavelets with ultra-wide band Radar. The main research works of this dissertation are aimed to design of Radar waveform and the application of wavelets in ultra-wide Radar, including: the design of a new kind of hybrid Radar and the research of time side-lobe suppression for pulse compression, the design of receiver radio front end in data acquisition of ultra-wide band Radar, the time delay estimation based on wavelets (packet) analysis.1 In the research of design of Radar waveform, one kind of hybrid radar waveform obtained by combining the chirp waveform with the non-periodic pseudorandom sequences is discussed. Through the theoretical analysis and computer simulation, several main characteristics of this kinds of hybrid waveforms are discussed, such as the ambiguity function, ambiguity graph, the spectrum, the weighting methods, the response of the processing filter and the low probability of interception. Those are showing the effectiveness of the new hybrid waveforms on the performance of high resolution and low probability of interception.2 In the research of time side-lobe suppression for pulse compression, a method designing mismatch network according to the desire waveform of compression pulse is proposed. Using this method the side-lobe level is suppressed more through double weighting in time domain. Universal theorem that the method is applicable is presented. Using the method to process the linear frequency modelsignal and the hybrid Radar waveform discussed above, the levels of side-lobe are suppressed more, especially for the hybrid Radar waveform and the hybrid Radar wavefomi is satisfied with the needs of Radar. The simulation results also show that the method can process the signal with Doppler frequency.3 In the research of time delay estimation in ultra-wide band Radar, a time delay estimation method based upon the multirate theory in wavelets analysis is proposed. In this method, time delay estimation is performed by decomposing and reconstructing in different levels and estimating time delay with least square method. There is no request for the characterization of signal and noise in the method. It is suitable for the time delay estimation in ultra-wide band Radar. The simulation results prove the effectiveness of this method. The simulation results also show that the method can process the signal with Doppler frequency.4 In the research of time delay estimation in ultra-wide band Radar, a time delay estimation method based upon the wavelets packet analysis is proposed too. The difference between this approach and time delay estimation method proposed upon is that time delay estimates in designated resolution and node through different time delay process on source signal instead of reconstruction to improve the 'accuracy of time delay estimation and to accelerate the processing speed. There is no request for the characterization of signal and noise in the method. It is suitable for the time delay estimation in ultra-wide band Radar. The simulation results prove the effectiveness of this method, and also show that the method is effective for indetectable goal.5 A project of ultra-wide band Radar receiver is proposed. Resolve some key problems during the experiment. And receiver radio front end is developed successfully.