Tang Rugang, Shen Fang, Pan Yanqun, Ruddick Kevin, Shang Pei
Opt Express. 2019 Mar 4;27(5):6426-6441. doi: 10.1364/OE.27.006426.
In this study, cross-comparisons of the reflectance at the top of atmosphere (ρ), atmospherically corrected water-leaving reflectance (R), and suspended sediment matter (SPM) concentration derived from three high spatial resolution sensors (Landsat-8/OLI, Sentinel-2A/MSI and GF-1/WFV) were conducted. The purpose was to examine the consistency among multi-source satellite products and their potential to fill the temporal gap of high-resolution satellites time series. Geostationary ocean color imager (GOCI) data and in situ data were used to verify the accuracy and reliability of the high-resolution satellite derived products. The results showed that the ρ and R data of high-resolution sensors were consistent with GOCI data, especially at the red spectral ranges. The satellite-derived SPM concentrations exhibited good agreement and acceptable errors when compared with both GOCI-derived and in situ SPM data. With regard to the influence of the signal-to-noise ratios, the results showed that the radiometric sensitivities of GF-1/WFV and Landsat-8/OLI were relatively high and presented minimally detectable variations greater than 0.06% in the ρ and 0.5 mg/L in the SPM concentration for solar zenith angles < 30°. However, the spatial resolution's impact on the SPM data can be greater than that of the signal-to-noise ratio for turbid waters.
在本研究中，对来自三个高空间分辨率传感器（Landsat-8/OLI、Sentinel-2A/MSI和GF-1/WFV）的大气顶反射率（ρ）、大气校正离水反射率（R）和悬浮沉积物（SPM）浓度进行了交叉比较。目的是检验多源卫星产品之间的一致性及其填补高分辨率卫星时间序列时间间隙的潜力。利用地球静止海洋彩色成像仪（GOCI）数据和现场数据来验证高分辨率卫星衍生产品的准确性和可靠性。结果表明，高分辨率传感器的ρ和R数据与GOCI数据一致，尤其是在红色光谱范围内。与GOCI衍生的和现场的SPM数据相比，卫星衍生的SPM浓度表现出良好的一致性和可接受的误差。关于信噪比的影响，结果表明，对于太阳天顶角<30°的情况，GF-1/WFV和Landsat-8/OLI的辐射灵敏度相对较高，ρ的最小可检测变化大于0.06%，SPM浓度的最小可检测变化大于0.5mg/L。然而，对于浑浊水体，空间分辨率对SPM数据的影响可能大于信噪比的影响。
