【摘要】 利用珠江口海域4个航次共59个站位的实测遥感反射比和悬浮泥沙数据(悬浮泥沙浓度范围为4—140g.m-3),建立了利用MERIS遥感数据反演珠江口悬浮泥沙浓度的分段算法。算法以Rrs(620)/Rrs(560)=0.9为阈值,当Rrs(620)/Rrs(560)<0.9时,红绿波段比值可以较好地反演悬浮泥沙浓度。随着悬浮泥沙浓度的增加,Rrs(620)/Rrs(560)>0.9,红绿比值趋于饱和,对悬浮泥沙的变化响应不敏感,此时采用包含红波段和近红外波段的波段比值提取水体的悬浮泥沙浓度。利用该分段算法从MERIS遥感图像中提取珠江口水体的悬浮泥沙浓度分布,得到较好的结果。更多还原

【Abstract】 A piecewise algorithm for retrieval of suspended sediment concentration based on the Medium Resolution Imaging Spectrometer(MERIS) data is developed by analyzing the spectral response of suspended sediment concentration ranging from 4 g·m-3 to 140 g·m-3 at 59 stations in the Zhujiang River estuary during four cruises.The threshold value of the piecewise algorithm is Rrs(620)/Rrs(560) equal to the threshhold.When the value of Rrs(620)/Rrs(560) is lower than the threshhold,the suspended sediment concentration is low and the ratio of red band to green band is fit for retrieving suspended sediment concentration.With the increase of suspended sediment concentration,the ratio of Rrs(620)/Rrs(560) becomes larger than the threshhold,the ratio of red band to green band reaches saturation and its response is insensitive to the change suspended sediment concentration.In this case,red band and near infrared band are considered in retrieving the suspended sediment concentration.The piecewise algorithm is applied to the MERIS satellite data obtained on January 31,2007.The distribution image of suspended sediment shows that the algorithm could be a useful tool for studying suspended sediment distribution in the Zhujiang River estuary.更多还原