四十里湾透明度的遥感估测模型研究

Study on remote sensing estimate model of transparency of seawater in Sishili Bay,China

以四十里湾为研究区,通过对2009年6月四十里湾海域实测高光谱数据的分析处理,得到一阶差分光谱和二阶差分光谱。分别对遥感反射率及其一阶、二阶差分光谱与实测透明度进行相关分析,发现后者的相关系数比前两者高出约11%,达到0.88。研究表明:用695 nm处的二阶差分光谱建立的透明度估测模型的决定系数、均方根误差和平均相对误差分别为0.79、0.1 m和7.9%,高于单波段模型和多波段模型。利用同年4月同一海域的数据作为独立样本进行检验,验证模型的均方根误差和平均相对误差分别为0.34 m、16%。本研究结果为近岸水体透明度高光谱遥感反演提供了一种新方法。

The reflectance spectra and secchi disk depths（SDD） in seawater were collected from two cruises carried out in Sishili Bay in Apr. 3un. 2009. The original spectra with 0.19 nm spectral resolution were re-sampled to 10 nm, and then the first-order and second- order difference spectra were processed. The correlation analysis was performed between SDD and each band. The correlation coeffi- cients between SDD and the second-order difference spectra are about 11% hither than others. The estimation model of SDD was estab- lished using the second-order difference spectra at the wavelength of 695 nm on the base of the analytical result. The result showed that this model performed better than the single-band and multi-band models,with the root mean square error （RMSE） of 0.1 m and the average relative error （SE） of 7.9%, respectively. The data obtained from in the same study area in Apr. 2009 as independent samples was used to test this model, and the verification modelg RMSE of 0. 34 m and SE of 16%. It is suggested a new way for water transpar- encv in the Chinese coastal waters.