MERIS数据以其更为合理的水色波段设置和300m较高的空间分辨率,在内陆湖泊水环境遥感监测中有较大的应用潜力,对其进行有效的大气校正则是水环境参数定量化反演的前提。以太湖为研究区,研究基于氧气和水汽吸收波段的暗像元为假设条件,...MERIS数据以其更为合理的水色波段设置和300m较高的空间分辨率,在内陆湖泊水环境遥感监测中有较大的应用潜力,对其进行有效的大气校正则是水环境参数定量化反演的前提。以太湖为研究区,研究基于氧气和水汽吸收波段的暗像元为假设条件,改进传统的近红外波段暗像元大气校正方法,采用MERIS level 2p数据辅助获取湖区气溶胶参数,并利用2007-11-11、2008-11-20以及2009-04-25等3景MERIS影像进行验证。结果表明,该方法能够快速、有效地完成MERIS影像的大气校正,与地面准同步实测数据相比,3次校正的均方根百分比RMSP(Root Mean Square of Percentage)、都在25%以下;与Beam自带的二类水体大气校正算法、气溶胶厚度辅助的6S大气校正以及改进的暗像元算法进行精度比较,结果表明该方法校正精度较高。由于该方法不需要同步实测气溶胶数据,因此具有一定的适用性。展开更多
This paper suggests a group of statistical algorithms for calculating the total absorption coefficients based on in situ data of apparent optical property and inherent optical property collected with strict quality as...This paper suggests a group of statistical algorithms for calculating the total absorption coefficients based on in situ data of apparent optical property and inherent optical property collected with strict quality assurance according to NASA ocean bio-optic protocols in the Yellow Sea and the East China Sea in spring 2003. The band-ratios ofRrs412/Rrs555, Rrs49o/Rrs555 are used in the algorithms to derive the total absorption coefficients （at） at 412, 440, 488, 510, 532 and 555nm bands, respectively. The average relative errors between inversed and measured values are less than 25.8%, with the correlative coefficients （R2） being 0.75-0.85. Error sensitivity analysis shows that the maximum retrieval error is less than 24.0% at ＋5% error in Rrs＇s. So the statistical algorithms of this paper are practicable. In this paper, the relations between the total absorption coefficients at 412, 488, 510, 532, 555 nm and that of 440nm are also studied. The results show that the relations between the total absorption coefficients of 400-600 nm and that of 440 nm are correlated well and all of their correlative coefficients R2 are greater than 0.99. Furthermore, a regression analysis is also done for the slope of the linear relations and wavelengths, and the R2 is also 0.99. Thus it is possible to retrieve other bands＇ total absorption coefficients with only one band absorption value, which significantly reduce the number of unknown parameters in studying other ocean color related problems.展开更多
A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increas...A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of waterturbidity. Thus, in very turbid coastal and inland waters, the radiance at 412 nm can be used to estimate the aerosolscattering radiance at 865 nm. The performance of the new algorithm is validated with simulation for several cases. Itis found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands ofSeaWiFS. This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuaryand the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmosphericcorrection algorithm creates a mask due to atmospheric correction failure. The result proves the efficiency of thissimple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.展开更多
文摘MERIS数据以其更为合理的水色波段设置和300m较高的空间分辨率,在内陆湖泊水环境遥感监测中有较大的应用潜力,对其进行有效的大气校正则是水环境参数定量化反演的前提。以太湖为研究区,研究基于氧气和水汽吸收波段的暗像元为假设条件,改进传统的近红外波段暗像元大气校正方法,采用MERIS level 2p数据辅助获取湖区气溶胶参数,并利用2007-11-11、2008-11-20以及2009-04-25等3景MERIS影像进行验证。结果表明,该方法能够快速、有效地完成MERIS影像的大气校正,与地面准同步实测数据相比,3次校正的均方根百分比RMSP(Root Mean Square of Percentage)、都在25%以下;与Beam自带的二类水体大气校正算法、气溶胶厚度辅助的6S大气校正以及改进的暗像元算法进行精度比较,结果表明该方法校正精度较高。由于该方法不需要同步实测气溶胶数据,因此具有一定的适用性。
基金Supported by the Subsystem of Calibration and Validation, HY-1 Ground Application System, National Satellite Ocean Application Ser-vice (NSOAS). China High-Tech "863" Project (Nos. 2001AA636010, 2002AA639160 and 2002AA639200). The Ocean Science Fund Sponsor Project for the Youth, State Oceanic Administration (No. 2005415). The Director’s Science and Technology Fund Sponsor Project for the Youth, NSOAS.
文摘This paper suggests a group of statistical algorithms for calculating the total absorption coefficients based on in situ data of apparent optical property and inherent optical property collected with strict quality assurance according to NASA ocean bio-optic protocols in the Yellow Sea and the East China Sea in spring 2003. The band-ratios ofRrs412/Rrs555, Rrs49o/Rrs555 are used in the algorithms to derive the total absorption coefficients （at） at 412, 440, 488, 510, 532 and 555nm bands, respectively. The average relative errors between inversed and measured values are less than 25.8%, with the correlative coefficients （R2） being 0.75-0.85. Error sensitivity analysis shows that the maximum retrieval error is less than 24.0% at ＋5% error in Rrs＇s. So the statistical algorithms of this paper are practicable. In this paper, the relations between the total absorption coefficients at 412, 488, 510, 532, 555 nm and that of 440nm are also studied. The results show that the relations between the total absorption coefficients of 400-600 nm and that of 440 nm are correlated well and all of their correlative coefficients R2 are greater than 0.99. Furthermore, a regression analysis is also done for the slope of the linear relations and wavelengths, and the R2 is also 0.99. Thus it is possible to retrieve other bands＇ total absorption coefficients with only one band absorption value, which significantly reduce the number of unknown parameters in studying other ocean color related problems.
基金This study was supported by the National“863”Project of China under contract No.2002AA639490 and No.2002AA639220.
文摘A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of waterturbidity. Thus, in very turbid coastal and inland waters, the radiance at 412 nm can be used to estimate the aerosolscattering radiance at 865 nm. The performance of the new algorithm is validated with simulation for several cases. Itis found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands ofSeaWiFS. This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuaryand the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmosphericcorrection algorithm creates a mask due to atmospheric correction failure. The result proves the efficiency of thissimple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.
