机载激光测深海水后向散射包络的频域分析

Frequency Analyzing of Backscattering Signals in Airborne Laser Bathymetry

根据机载激光测深海水后向散射雷达方程 ,在机载激光测深系统典型参数情况下 ,详细分析了海水衰减系数、海水反照率、飞机高度以及光学接收系统全视场角对海水后向散射频谱的影响。得到了 :当衰减系数C从 0 .2 /m变到 0 .9/m时 ,后向散射包络频谱将展宽2 36MHz ;当海水反照率ω从 0 .1变到 0 .9时 ,后向散射包络频谱将展宽 2 2 0MHz ;机载激光测深系统接收视场角和飞机高度对系统探测到的海水后向散射包络频率无显著影响 ;当最小可探测功率Pb=1.5 6× 10 - 10 W时 ,在典型的实验参数条件下后向散射包络的频率范围为 0 <f<5 .6× 10 8Hz。

In terms of Airborne laser bathymetry backscatter ing lider equation,the backscattering envelop is analyzed in the field of frequency.The frequency included in backscatter envelop would broad 236MHz and 220MHz when the attenuation coefficient of sea water changes from 0.2/m to 0.9/m and the albedo of the sea water changes from 0.1 to 0.9 respectively.The altitude of the plane and the optical receiver field of view have little effect on the frequency of backscattering signals.When the sensitivity of the detecting system is 1.56×10 -10 W,the frequency width of backscattering envelop is 0<f<5.6×10 8Hz,under the typical experimental parameters.