江苏近岸海域HJ CCD影像悬浮泥沙遥感反演

基于2012~2014年期间江苏近岸海域实测遥感反射率、悬浮泥沙浓度及HJ CCD数据,建立该海域HJ CCD影像悬浮泥沙遥感反演模型。通过研究水体实测反射光谱特征,确定对悬浮泥沙浓度变化的敏感波段,并与悬浮泥沙浓度进行函数拟合分析。结果表明:将HJ CCD Band3的等效遥感反射率、HJ CCD Band3与Band2等效遥感反射率的比值分别作为敏感因子,并采用对数函数模拟低值区、指数函数模拟高值区获得的叠加模型表现最为突出。通过卫星应用发现,第2、3波段比值模型的遥感反演结果与实际情况相符,可有效削弱大气校正、表观反射率到遥感反射率的转换方法以及HJ CCD辐射分辨率较低等一系列问题的干扰,为江苏近岸海域HJ CCD悬浮泥沙遥感反演的最优模型。

Retrieval of suspended sediment concentration from HJ-CCD imagery in Jiangsu coastal sea

Based on in-situ measured remote sensing reflectance (R_rs), suspended sediment concentration (SSC), and HJ-CCD imagery in the Jiangsu coastal sea, we established a remote sensing retrieval model for suspended sediment. By analyzing the measured spectral reflectance, we can determine the most sensitive of the SSC bands, and fit the SSC to different functional forms. The results indicate that the equivalent R_rs at HJ-CCD Band 3 and the ratio of the equivalent band-3 Rrs to that at band 2, respectively, can be used as sensitivity factors. We simulated the SSC vs. sensitivity factor using the logarithm model in the low area, and the exponential model in the high area. The superposition model is optimal. By satellite application, we found that the retrieval results of the ratio model to be consistent with the actual situation, effectively weakening a series of interference factors, including, for example, the atmospheric correction, the method used for converting apparent reflectance to remote sensing reflectance, and the low radiation resolution on the HJ CCD. This is the optimal SSC retrieval model for the Jiangsu coastal sea.