SeaWiFS和MODIS叶绿素浓度数据及其融合数据的全球可利用率

对2001年Sea WiFS和MODIS叶绿素浓度数据的全球可利用率进行了定量分析，二者在全球范围的变化趋势一致，年平均可利用率分别为12．4％和13．6％，其中MODIS叶绿素浓度的可利用率略高于SeaWiFS。利用小波变换方法对二者进行数据融合，经分析：SeaWiFS／MODIS叶绿素浓度融合数据相对于单一传感器数据提高了全球可利用率，其年平均为20．50％；融合数据保持了较高空间分辨率MODIS数据的海洋特征；融合数据与实测值比较，差值的均值和标准偏差分别为0．16mg／m^3和1．07mg／m0（SeaWiFS：0．46mg／m^3和2．22mg／m^3，MODIS：0．13mg／m^3和0．82mg／m^3）。与MODIS和Sea WiFS相比。融合数据接近MODIS优于SeaWiFS。结果表明小波变换方法用于SeaWiFS和MODIS叶绿素浓度数据融合的有效性。

The Global Availabilities of SeaWiFS, MODIS and Merged Chlorophyll-a Data

The global availabilities of the chlorophylla (chl-a) concentration from SeaWiFS and MODIS in 2001 were evaluated.The variations of the availabilities are consistent.But the availability of MODIS is higher than that of SeaWiFS and the annual availabilities of SeaWiFS and MODIS are 12.4% and 13.6%,respectively.The chl-a concentration data from SeaWiFS and MODIS were merged using wavelet transform.The availability of the merged data increased,the annual mean availability being 20.50%.The oceanic features of higher spatial resolution data from MODIS are preserved.The bias and standard deviation of the merged data against in-situ data are 0.16mg/m~3 and 1.07mg/m~3,respectively(The bias and standard deviation of SeaWiFS data against in-situ data are 0.46mg/m~3 and 2.22mg/m~3,respectively,and for MODIS data they are 0.13mg/m~3 and 0.82mg/m~3,respectively).In comparison with SeaWiFS and MODIS data,the accuracy of the merged data is close to MODIS and superior to SeaWiFS. These results show that wavelet transform is an effective method for merging chl-a data from SeaWiFS and MODIS.