湖泊水体叶绿素a含量估算的波段宽度变化影响分析——以太湖为例

为研究不同波段宽度遥感数据对监测水体叶绿素a含量的影响,以太湖水体实测高光谱遥感反射率数据为基础,分析计算不同波段宽度下遥感反射率的归一化值与叶绿素a浓度之间的相关系数。随着波段宽度在75.93nm范围内不断递增,最大相关系数逐渐减小,最大正相关波段向长波方向移动,最大负相关波段向短波方向移动。而波段宽度在31.6nm范围内变化时,最大正相关波段和最大负相关波段都会保持相对稳定。通过对不同波段处相关系数平均值和标准差的对比分析认为,718.77^~34.58nm为叶绿素a遥感监测的最佳波段范围。这将对遥感传感器的波段设置,以及实际水体叶绿素a遥感监测时的波段选择,具有重要的参考价值。

The Influence of Bandwidth's Variety on Estimating Chlorophyll-a Concentration of Lake Waters: Taking Taihu Lake as an Example

In order to study the influence of different bandwidth's remote sensing data on estimating chlorophyll-a concentration in waters,this paper analyzes and calculates the correlation coefficient between normalized reflectance of different bandwidth and chlorophyll-a concentration based on real-measurement hyperspectral reflectance.With constant increase of bandwidth in a scope of 75.93nm,it has found that the maximum correlation coefficient decreases by degrees,the maximum positive correlation band moves to long wave,the maximum negative correlation band moves to short wave while estimating chlorophyll-a concentration in waters.As the bandwidth changes in the scope of 31.60nm,both the maximum positive correlation band and the maximum negative correlation band will keep a relative stable state.Finally,through contrasting the mean and standard deviation of different bandwidth's correlation coefficient,we think 723.51nm~733.00nm is the best band range for estimating chlorophyll-a concentration.This will provide important reference value for band setting of remote sensing sensor and band choosing of real chlorophyll-a estimation by remote sensing in water.