Ee Ct Of Spectral Bandwidth And Spaa ⅠScale Of Mul-sensors Data On Remote Sensing Of Ocean Color

With the expansion and in-depth of applications and requirements of ocean color remote sensing technology, the requirements of quality of remote sensing data are continuously being high, and the quality of remote sensing data and the accuracy of inversion has become the focus of the field of ocean color remote sensing. In this study, According to the sensors’characteristics, including relative spectral response (RSR), bandwidth and spatial resolution, we discuss the effect of spectral response (RSR), bandwidth and spatial resolution on the inversion of ocean color in the Yangtze estuarine and coastal waters, which are optically complex case2waters. And then we eliminate the error caused by these sensors’characteristics of the inversion of ocean color, and improve the quality of remote sensing data and the accuracy of inversion.(1) Compare the characteristics of the following five sensors: Landsat5/TM, Terra/Aqua/MODIS, ENVISAT/MERIS, FY-3A/MERSI and COMS/GOCI. Landsat5/TM launched earliest (March1984), and the spatial resolution(30m) is the highest of all five sensors. But it’s spectral band widths are relatively large (the bandwidth of TM4is66-129nm);The width of scan of Terra/Aqua/MODIS is2330km, and it can monitor a large range at the same time; The channels of ENVISAT/MERIS are very fine, and can characterize the optical properties of waters of the whole visible and the near-infrared (NIR)spectral ranges; Channel8to16of FY3-A/MERSI is visible and the near-infrared bands with high signal to noise ratio; COMS is a Geostationary satellite orbit satellite. So the time resolution of COMS/GOCI is the largest of five sensors, and it can be revisited many times in the area of the Yangtze estuary each day.(2) Due to the complexity of the optical properties of case2waters, the accuracy of remote sensing data are particularly high requirements in the study of ocean color. We discussed the effects of relative spectral response (RSR) and bandwidth of Terra/MODIS and Landsat5/TM channels on water-leaving reflectance (Rrs(λ)) in optically complex case2waters, thereby improving the accuracy of remote sensing data. The result show that the Rrs(λm) of the channels can’t characterize spectral properties of case2waters because of the RSR and bandwidth. And the effects of MODIS’s RSR and bandwidth on Rrs(λm) are much smaller than that of TM’s RSR and bandwidth on Rrs(λm). By quantitative analysis, the effects of RSR and bandwidth on Rrs(λm) are different for different channels and water types. For three types of waters, we use the Rrs(λm) of each TM channel to simulate Rrs(λ) of the entire channel, and thus characterize spectral properties of case2waters within the channel, and eventually eliminate the effects of the SAS and bandwidth. (3)Analysis the effect of the spatial resolution on the inversion of ocean color. At first, we analysis the spatial heterogeneity of suspended sediment concentration in the Yangtze estuary. Then, we the use of the synchronous Landsat5/TM data to calibrate the spatial scale effect of the SSC inversion from ENVISAT/MERIS data which is with lower spatial resolution. The results show that the parameters of semivariogram (nugget, sill and the change process, etc.) can effectively describe the spatial heterogeneity of the suspended sediment concentration distribution of the Yangtze estuary, the spatial heterogeneity of the suspended sediment concentration is caused by both the random element and the extent of spatial auto-correlation. The scale error of the suspended sediment concentration is mainly caused by the spatial heterogeneity; With the increase of the suspended sediment concentration, the scale error is increasing. By up scaling, use the synchronous Landsat5/TM data to calibrate the spatial scale effect of the suspended sediment concentration inversed from ENVISAT/MERIS data of the Yangtze estuary. After scale correction, the SSCr is more close SSCmean and the scale error of the inversion is eliminated. By Down scaling, SSC inversed from ENVISAT/MERIS after scale correction can reflect the spatial distribution of the suspended sediment concentration of the Yangtze estuary with higher spatial resolution.