混沌脉冲激光雷达水下目标探测

海水对光波的吸收和散射，严重制约了激光雷达水下目标探测的性能。通过对激光在海水传输过程中产生后向散射的定量分析，说明了激光回波信号被海水后向散射影响的严重性。分析比较了距离选通技术和强度调制技术抑制海水后向散射的能力，提出了使用自身具有高频强度调制特性的混沌脉冲激光进行水下目标探测，设计了基于相关法测距的混沌脉冲激光雷达水下目标探测方案。通过对后向散射光以及带有不同后向散射强度的回波信号光的时域和频域特性的研究，使用互相关噪声水平算法判定混沌脉冲激光雷达抑制海水后向散射的能力。理论仿真分析表明，当后向散射光强度是混沌脉冲激光强度36倍时，仍能提取出目标信号。

Underwater target detection of chaotic pulse laser radar

Absorption and scattering of seawater for light waves seriously restrict the performance of laser radar for underwater target detection. Quantitative analysis of laser backscattering generated by seawater shows that the laser echo signal is seriously affected by seawater backscattering. The ability of range-gated technology and intensity modulation technology to suppress backscattering of seawater was analyzed and compared. A chaotic pulse laser with high frequency intensity modulation was proposed for underwater target detection and the scheme was designed. Based on the study of the characteristics of backscattering light and echo signal with different backscattering intensity in time and frequency domain, the ability of chaotic pulse lidar to suppress backscattering from seawater was determined by using cross-correlation noise level algorithm. The theoretical analysis shows that the target signal can still be extracted when the backscattered light intensity is 36 times that of the chaotic pulse laser.