高光谱遥感技术在悬沙水体研究中的应用

Application of Hyper-Spectral Remote Sensing in the Study of Water Body Containing Suspended Particles

水体中悬浮泥沙影响到水体的透明度和水色等光学性质,还密切关系到河口海岸冲淤变化过程。采用高光谱遥感技术获得悬沙水体的反射光谱数据,同时从原理上来计算反射率。针对传统水体遥感测量的局限性,地物光谱仪测量方式更加合理。选用地物光谱仪和光纤光谱仪进行研究,得到以下结论:随着悬沙浓度的增高,反射率也增高,且发生反射的波段范围有所增大;离水面一定距离时测得的悬沙反射率的误差主要来自于天空光,近水面虽然减少了天空光的部分影响,但光纤光谱仪较敏感,受水面波动的影响较大;到水面下光强变弱,利用光纤光谱仪可以不受天空光影响直接获得水体反射率。

Suspended sediments affect the water＇s optic character, such as transparence and water color, and matter the fluvial change of estuary and coast. By way of hyper-spectral remote sensing, we have gained the reflex spectrums of water body containing suspended particles and calculated the reflectivity theoretically. Field spectrograph adopts a better mode compared with the traditional. With the aid of fiber optical spectrograph and field spectrometer, this study concludes that： along with the growing of suspended particles＇ concentration, reflectivity gets higher and the boundary of wave band is extending; on the surface of water, the error of reflectivity mainly comes from ambient stray light; near the surface, it can decrease the influence of ambient stray light to the reflectivity, but it is affected by water movement as the fiber optical spectrograph is sensitive to light; underneath the surface, as the beam gets weaker, the fiber optical spectrograph can get the reflectivity directly with no influence of the ambient stray light.