基于短波红外波段的乌梁素海Landsat-8 OLI数据大气校正

采用基于短波红外波段的Vanhellemont和Ruddick算法对乌梁素海水体的Landsat-8业务陆地成像仪(Operational Land Imager, OLI)数据进行了大气校正。用该算法得到的OLI反射率与ENVI Flaash大气校正结果之间具有很好的一致性，且R2为0.8。经大气校正后得到的OLI反射率与实测值吻合得较好，而且483 nm、561 nm和655 nm波段的误差在19.3%～36.5%之间，表明该算法适用于乌梁素海水体。基于时间序列OLI数据，得到了悬浮物浓度的时空分布特征。乌梁素海的悬浮物浓度反演结果存在一定的不确定性，其主要原因是底质、沉水植物和藻华对离水反射率有很大影响。

Atmospheric Correction of Landsat-8 OLI Data for Wuliangsuhai Lake Based on SWIR Bands

Atmospheric correction of the data about Wuliangsuhai Lake from the Operational Land Imager (OLI) onboard Landsat-8 was carried out by using the Vanhellemont & Ruddick algorithm based on shortwave infrared bands. The OLI reflectance derived by this algorithm agreeded well with that from the ENVI Flaash model. Its correlation coefficient was 0.8. The OLI reflectance derived after atmospheric correction was well consistent with the measured value. Their errors at the wavelengths of 483 nm, 561 nm and 655 nm were in the range from 19.3% to 36.5%. This showed that this algorithm was suitable for Wuliangsuhai Lake. On the basis of time series data from the OLI onboard Landsat-8, the temporal and spatial distribution characteristics of suspended particulate matter concentration were obtained. However, there existed some uncertainties in the retrieval result of suspended particulate matter concentration in Wuliangsuhai Lake. The main reason was that the reflectance from the bottom, submergedvegetation and algae bloom in the lake had great influences on the water leaving reflectance.