步进频雷达低空环境感知与监控软件开发
发布时间：2018-10-17 13:21
【摘要】：随着我国低空环境的进一步开放,低空飞行器数量明显增多,低空飞行环境日益复杂,对低空环境感知技术的需求日益迫切。针对低空环境静止场景的感知问题,展开了步进频雷达目标距离维高分辨成像方法的研究。传统的获取步进频雷达高分辨一维距离像的方法需要繁琐的去冗余处理,针对该问题,本文采用合成带宽法来获取步进频体制下目标的高分辨一维距离像。该方法具体步骤如下:首先选取一帧完整的回波,并对单个脉冲进行升采样操作;然后对回波进行脉冲压缩处理;之后对脉冲进行频谱搬移操作;最后由频谱搬移结果合成一个等效的大带宽信号。仿真数据处理结果表明,在低信噪比情况下,合成带宽法对目标的检测性能较之于传统的选大法、累加法等有明显优势。针对低空环境运动场景的感知问题,展开了强弱运动目标成像方法的研究,提出了基于帧间互相关速度搜索的多运动目标成像方法。该方法分两次得到运动目标的参数估计结果。第一次速度估计过程如下:首先对回波数据进行帧间互相关操作,以实现距离-速度的解耦和;然后在对帧间互相关结果进行帧内包络非相干积累的基础上,依据3dB原则挑选有效样本,并由有效样本构造速度搜索协方差矩阵;之后对协方差矩阵进行特征值分解,并由单次快拍方法得到运动目标的速度谱;最后通过峰值搜索得到运动目标的第一次速度估计结果。进行第二次速度估计时,首先利用第一次速度估计结果对原始回波进行速度补偿和距离徙动校正,然后对校正结果进行脉冲压缩处理,之后对脉压结果进行帧内距离合成,最后对合成结果进行帧间FFT成像,由成像结果的多普勒偏移得到速度估计残差,进而得到第二次速度估计结果。利用第二次速度估计结果对原始回波进行速度补偿、距离徙动校正,在完成脉冲压缩、帧内距离合成及帧间FFT操作后,得到最终的成像结果。通过对最终成像结果的搜索得到运动目标的初始位置信息。为了避免当前强目标的影响,提出了一种基于正交投影的强目标抑制方法,该方法利用第二次速度估计结果构造正交投影矩阵,对帧间互相关后的数据进行投影处理,实现了对当前强目标的抑制。该方法具有速度估计精度高,速度不模糊范围大,成像聚焦效果好等优点。针对多源感知集成显示的问题,开发了低空环境多源传感器协同探测地面监控软件。该软件采用服务器-客户端模式,其中,客户端为各个传感器,服务器为地面显示基站;为保障传输过程中数据的安全性及有序性,采用面向链接的方式进行数据传输;编程平台选用VC6.0;网络通信编程实现采用套接字技术;为了确保数据传输不影响到其他操作,采用多线程编程方法。该软件实现了多源探测结果的并行、动态显示。
[Abstract]:With the further opening of low-altitude environment in our country, the number of low-altitude aircraft is increasing obviously, the low-altitude flying environment is becoming more and more complex, and the need for low-altitude environment sensing technology is becoming more and more urgent. Aiming at the problem of perception of stationary scene in low altitude environment, the high resolution imaging method for target range of stepped frequency radar is studied. The traditional method of obtaining high-resolution one-dimensional range profile of stepping frequency radar needs tedious de-redundancy processing. In order to solve this problem, the synthetic bandwidth method is used to obtain the high-resolution one-dimensional range profile of target in step frequency system. The specific steps of the method are as follows: firstly, a frame of complete echo is selected and a single pulse is raised and sampled; then, the echo is processed by pulse compression, and then the pulse spectrum is moved. Finally, an equivalent large bandwidth signal is synthesized from the result of spectrum shift. The results of simulation data processing show that the performance of the synthetic bandwidth method is better than that of the traditional selection method and the accumulative method in the case of low signal-to-noise ratio (SNR). Aiming at the problem of perception of moving scenes in low altitude environment, the imaging method of strong and weak moving targets is studied, and a multi-moving target imaging method based on inter-frame cross-correlation velocity search is proposed. In this method, the parameter estimation results of moving targets are obtained in two stages. The first velocity estimation process is as follows: firstly, the echo data is cross-correlated between frames to realize the distance velocity decoupling, and then based on the intra envelope incoherent accumulation of the inter-frame cross-correlation results, The effective samples are selected according to the 3dB principle, and the velocity search covariance matrix is constructed from the effective samples, then the eigenvalue decomposition of the covariance matrix is carried out, and the velocity spectrum of the moving target is obtained by the single shot method. Finally, the first velocity estimation result of moving target is obtained by peak search. In the second velocity estimation, the first velocity estimation results are used to compensate the original echo and the range migration correction, then the correction results are processed by pulse compression, and then the pulse compression results are synthesized by intra-frame distance synthesis. Finally, the composite results are imaged by inter-frame FFT imaging, and the velocity estimation residuals are obtained from the Doppler migration of the imaging results, and then the second velocity estimation results are obtained. The velocity compensation and range migration correction of the original echo are carried out by using the second velocity estimation result. The final imaging results are obtained after the pulse compression, intra-frame distance synthesis and inter-frame FFT operation are completed. The initial position information of the moving target is obtained by searching the final imaging results. In order to avoid the influence of the current strong targets, a strong target suppression method based on orthogonal projection is proposed. The orthogonal projection matrix is constructed by using the second velocity estimation result, and the cross-correlation data between frames are projected. The suppression of the current strong target is realized. This method has the advantages of high accuracy of velocity estimation, wide range of velocity nonblur, good imaging focusing effect and so on. In order to solve the problem of multi-source sensing integrated display, a ground monitoring software for multi-source sensor cooperative detection in low altitude environment is developed. The software adopts the server-client mode, in which the client is each sensor and the server is the ground display base station, in order to ensure the security and order of the data in the transmission process, the data transmission is carried out in the way of link oriented. In order to ensure that the data transmission does not affect other operations, the multi-thread programming method is adopted. The software realizes the parallel and dynamic display of multi-source detection results.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52
本文编号：2276788
[Abstract]:With the further opening of low-altitude environment in our country, the number of low-altitude aircraft is increasing obviously, the low-altitude flying environment is becoming more and more complex, and the need for low-altitude environment sensing technology is becoming more and more urgent. Aiming at the problem of perception of stationary scene in low altitude environment, the high resolution imaging method for target range of stepped frequency radar is studied. The traditional method of obtaining high-resolution one-dimensional range profile of stepping frequency radar needs tedious de-redundancy processing. In order to solve this problem, the synthetic bandwidth method is used to obtain the high-resolution one-dimensional range profile of target in step frequency system. The specific steps of the method are as follows: firstly, a frame of complete echo is selected and a single pulse is raised and sampled; then, the echo is processed by pulse compression, and then the pulse spectrum is moved. Finally, an equivalent large bandwidth signal is synthesized from the result of spectrum shift. The results of simulation data processing show that the performance of the synthetic bandwidth method is better than that of the traditional selection method and the accumulative method in the case of low signal-to-noise ratio (SNR). Aiming at the problem of perception of moving scenes in low altitude environment, the imaging method of strong and weak moving targets is studied, and a multi-moving target imaging method based on inter-frame cross-correlation velocity search is proposed. In this method, the parameter estimation results of moving targets are obtained in two stages. The first velocity estimation process is as follows: firstly, the echo data is cross-correlated between frames to realize the distance velocity decoupling, and then based on the intra envelope incoherent accumulation of the inter-frame cross-correlation results, The effective samples are selected according to the 3dB principle, and the velocity search covariance matrix is constructed from the effective samples, then the eigenvalue decomposition of the covariance matrix is carried out, and the velocity spectrum of the moving target is obtained by the single shot method. Finally, the first velocity estimation result of moving target is obtained by peak search. In the second velocity estimation, the first velocity estimation results are used to compensate the original echo and the range migration correction, then the correction results are processed by pulse compression, and then the pulse compression results are synthesized by intra-frame distance synthesis. Finally, the composite results are imaged by inter-frame FFT imaging, and the velocity estimation residuals are obtained from the Doppler migration of the imaging results, and then the second velocity estimation results are obtained. The velocity compensation and range migration correction of the original echo are carried out by using the second velocity estimation result. The final imaging results are obtained after the pulse compression, intra-frame distance synthesis and inter-frame FFT operation are completed. The initial position information of the moving target is obtained by searching the final imaging results. In order to avoid the influence of the current strong targets, a strong target suppression method based on orthogonal projection is proposed. The orthogonal projection matrix is constructed by using the second velocity estimation result, and the cross-correlation data between frames are projected. The suppression of the current strong target is realized. This method has the advantages of high accuracy of velocity estimation, wide range of velocity nonblur, good imaging focusing effect and so on. In order to solve the problem of multi-source sensing integrated display, a ground monitoring software for multi-source sensor cooperative detection in low altitude environment is developed. The software adopts the server-client mode, in which the client is each sensor and the server is the ground display base station, in order to ensure the security and order of the data in the transmission process, the data transmission is carried out in the way of link oriented. In order to ensure that the data transmission does not affect other operations, the multi-thread programming method is adopted. The software realizes the parallel and dynamic display of multi-source detection results.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52
【参考文献】
相关博士学位论文 前1条
1 张焕颖;高速运动目标ISAR成像方法研究[D];西安电子科技大学;2007年
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