针对强地物杂波背景下弹载雷达目标检测与识别的技术难题,提出将高分辨距离像(high resolution range profile,HRRP)技术和多普勒波束锐化技术联合对地面进行二维高分辨成像,提高雷达在杂波下目标检测与识别的性能。该方法以线性调频步进频(linear frequency modulation stepped frequency,LFM-SF)信号为基本波形,首先对平台速度产生的多普勒效应等问题进行了详细讨论并校正;然后通过距离像抽取获得各帧对应的HRRP序列,并采用方位快速傅里叶变换(fast Fourier transform,FFT)实现方位高分辨;最后对实际飞行状态下平台造成的误差进行运动补偿,完成对波束内区域的二维分辨。实测数据的处理验证了所提算法的有效性与实用性。
Research on DBS technology of LFM-SF in strong clutter background
To address the technical problems of target detection and identification of missile-borne radar in the background of strong ground clutter,we propose to combine the high resolution range profile(HRRP)technology and Doppler beam sharpening(DBS)technology to carry out two-dimensional high-resolution imaging of the ground to improve the performance of radar target detection and identification in the presence of clutter.The method uses the linear frequency modulation stepped frequency(LFM-SF)signal as the basic waveform.Firstly,the Doppler effect caused by the platform speed is discussed in detail and corrected.Then,HRRP sequences corresponding to each frame are obtained through distance profile extraction,and azimuth high resolution is achieved using fast Fourier transform(FFT).Finally,motion compensation is applied to the errors caused by the platform in actual flight conditions,completing the two-dimensional resolution of the area within the beam.The processing of measured data has verified the effectiveness and practicality of the proposed algorithm.
clutterlinear frequency modulation stepped frequency(LFM-SF)high resolution one-dimensional range profileDoppler beam sharpening(DBS)motion compensation