一种车载调频连续波后向投影成像方法

A Method of Back-Projection Imaging Algorithm of Vehicle-mounted Frequency Modulation Continuous Wave

车载调频连续波成像是无人驾驶的关键技术,具有超宽带、宽波束等特点,使用常规距离维压缩方位向波束形成的成像方法在近场情况下会出现严重的距离走动,因此不再适用。为了实现方位向高分辨,本文提出一种基于后向投影的成像算法。首先通过计算成像区域内像素点到阵元天线之间的延时时间,其次对回波信号进行插值然后根据延时提取时域信号进行相参积累。该算法仅与时延有关,避免了菲涅耳近似,适用于近距离成像。文中推导了后向投影算法的成像原理并通过仿真分析验证了该算法的可行性和有效性。

Vehicle-mounted FMCW imaging is the key technology for autonomous vehicle,which features wide beam-width and ultra-wide band antenna.The abnormal imaging method based on distance compressive and azimuth beamforming was not are not valid any more for serious migration through resolution cell in the near field.In order to achieve the azimuth high resolution,the back projection imaging algorithm was proposed.Firstly,the delay time between pixels and antennas in the imaging field is calculated.Secondly,the echo signal was interpolated.According to the delay time,the coherent integration was obtained.The BP algorithm was just related to the delay time and applicable for near field imaging.Last,the theory is deduced and the feasibility and validity of the method are proved by simulation.