Study On Target Detection Methoed For Carrier-free Uwb Radar

In the field of target detection and recognition, obstacle penetration, anti-jammingand anti-reconnoitering, the carrier-free ultrawideband radar has various incomparableadvantages. It has become an ascendant research field of modern radar technology.There is non-carrier contained in transmit signals, the power of signal has alreadycentralized in the narrow waveform, and the relativity between transmit signals andreflected signals is weak, the detection method of cross-correlation receiver cannotachieve reliable detection result. In order to solve this problem, the new methods oftarget detection of carrier-free UWB radar have done.. Work of the thesis can besummarized as follows:1. Signal modeling of carrier-free ultra-wideband radar is discussed. Based onGaussian transmit signal and target response function, reflected signal model of carrier-free UWB radar is stated.2. A target detection method based on EMD of carrier-free UWB radar is proposed.The limitation of applying the classical matching filtering theory in the carrier-freeUWB radar is analyzed. According to the instability of the reflected waveforms of thecarrier-free UWB radar, the abilities of reconstruction and filtering of the EMDalgorithm are deliberated. Then the envelope aligning is used in accumulation reflectedwaveforms in multiple periods to accomplish target detection. Simulation resultsdemonstrate the validity of the presented method.3. Combined with EMD, a target detection method based on DPA of carrier-freeUWB radar is proposed. To benefit from the disadvantages of the detection methodbased on EMD, the TBD algorithm based on dynamic programming is applied in targetdetection of carrier-free UWB radar. Principles and flow paths are discussed in detail,and the performances of the method are analyzed. Simulation results are provided toprove the effectiveness of the method. Furthermore, combined the EMD process, anadvanced target detection method based on DPA is presented. The performances of theoriginal and the advanced method are compared and discussed in the followingsimulation experiments. 4. The effectiveness of the algorithm is validated with experimental data. A smallcarrier-free UWB radar system is constructed. By using the data collected from theexperimental system, the correctness of both target detection method are verified. It canbe concluded that both the target detection methods base on EMD and DPA can achieveeffective detection results.