利用分频带空间谱和波束域的输出直流跳变与起伏比值融合检测未知线谱目标

目标辐射噪声中高强度稳定线谱可以用来提高常规宽带能量积分的检测性能。理论分析了已知线谱检测优于宽带能量积分检测的谱级比条件。给出了线谱频带可检测条件下,线谱谱级与最小可检测信噪比关系。分析分频带空间谱和波束域的输出直流跳变与起伏比值特征。在此基础上提出了一种构造频率、方位滤波矩阵的方法。该矩阵作用类似频带方位滤波器,通过对线谱频带目标方位的信号放大,与其他频带判决结果融合,来提高常规宽带能量积分的性能。最后给出该算法适用条件和性能分析。数据仿真和海试数据处理结果可知,该算法在多干扰源存在下对弱线谱目标提取能力强,且不需多帧统计,在检测效果上更接近于理想的窄带线谱检测方法。 

A detecting method for line-spectrum target by fusing output DC jump to fluctuations ratio of sub-band spatial spectrum and beam space

The low frequency line elements that the underwater target radiates usually have both high spectrum level and sustained stability.This feature could be used for increasing the detecting performance of conventional wideband energy integration method.The required spectrum level is theoretically discussed when the known line detection is better than wideband energy integration method.The relationship between line spectrum level and signal to noise ratio (SNR) when the target could be detected in line sub band is also discussed.Then the article proposes a detecting method for line spectrum target by constructing a matrix by using output DC jump to fluctuations ratio of sub band spatial spectrum and beam space.The matrix acts as a filter letting the certain frequency and azimuth of goal line target pass at most.Thus by fusing with other sub band results,the detection performance of conventional method increases.At last,the paper analyzes the applicable condition and detection performance.The simulation and trial data processing results have proven this algorithm could effectively extracts weak goal line spectrum under the condition of multi-interference.It needs no multi frame statistics.The detection effect is closer to the known line spectrum method.