分析了分通道、距离选通、光电倍增管变增益、正交偏振等多种技术相结合的方法,用以改善机载激光测深系统中激光回波的动态范围。并研制了相应的变增益部件,开展了水池试验以及海上现场试验。试验结果表明,多种方法相结合的技术可对水底信号的动态范围进行有效压缩,满足机载测深系统对浅海测量的动态范围要求;但正交偏振技术对信号测量压缩的改善效果并不明显。报道了试验过程中出现的光电倍增管后脉冲对水深测量的影响。对动态范围压缩技术进一步研究提供了有价值的参考。

The techniques of channel separation, range gate, variable gain of photomultiplier tube and cross polarization are analyzed and combined to improve the dynamic range compression of the laser echo signal in airborne laser bathymetry. The corresponding device with variable gain is developed, and implemented in experiments in tank and sea in situ. Results show that the combined technique compresses the dynamic range of submarine signal effectively and meets the demand of shallow sea dynamic range for the airborne laser bathymetry. The technique of cross polarization does not improve the effect of measuring signal compression remarkably, and the influence of after pulse effect of photomultiplier tube on depth measurement is also reported. Valuable reference for further study on dynamic range compression is presented.