海洋通报
海洋通報
해양통보
MARINE SCIENCE BULLETIN
2014年
5期
576-583
,共8页
马翱慧%刘湘南%刘美玲%龙亚谦
馬翱慧%劉湘南%劉美玲%龍亞謙
마고혜%류상남%류미령%룡아겸
缺失数据重构%DIEOF%南海北部海域%叶绿素a%MODIS
缺失數據重構%DIEOF%南海北部海域%葉綠素a%MODIS
결실수거중구%DIEOF%남해북부해역%협록소a%MODIS
Reconstruction of Missing Data%DIEOF%Northern South China Sea%Chlorophyll a%MODIS
以2007年1月到2010年12月的MODIS Aqua CHL-a Level 2海表水色产品为基础数据,获得南海北部海域海表叶绿素a浓度的月平均影像集,基于影像集数据的时空相关性利用DIEOF (Data Interpolating Empirical Orthogonal Functions)方法重构其缺失数据。通过分析重构前后数据变化、验证重构结果的时空特征、计算模型精度指标等对重构结果进行评价。研究结果表明:DIEOF方法重构的MODIS海表叶绿素a影像,能够体现研究区海表叶绿素a的时空变化特征,重构结果的复相关系数R2可达到0.98,平均绝对误差MAE小于0.01;该方法重构过程中无需先验信息,易操作,能够有效重构大面积成片缺失或缺失比例较高的影像。
以2007年1月到2010年12月的MODIS Aqua CHL-a Level 2海錶水色產品為基礎數據,穫得南海北部海域海錶葉綠素a濃度的月平均影像集,基于影像集數據的時空相關性利用DIEOF (Data Interpolating Empirical Orthogonal Functions)方法重構其缺失數據。通過分析重構前後數據變化、驗證重構結果的時空特徵、計算模型精度指標等對重構結果進行評價。研究結果錶明:DIEOF方法重構的MODIS海錶葉綠素a影像,能夠體現研究區海錶葉綠素a的時空變化特徵,重構結果的複相關繫數R2可達到0.98,平均絕對誤差MAE小于0.01;該方法重構過程中無需先驗信息,易操作,能夠有效重構大麵積成片缺失或缺失比例較高的影像。
이2007년1월도2010년12월적MODIS Aqua CHL-a Level 2해표수색산품위기출수거,획득남해북부해역해표협록소a농도적월평균영상집,기우영상집수거적시공상관성이용DIEOF (Data Interpolating Empirical Orthogonal Functions)방법중구기결실수거。통과분석중구전후수거변화、험증중구결과적시공특정、계산모형정도지표등대중구결과진행평개。연구결과표명:DIEOF방법중구적MODIS해표협록소a영상,능구체현연구구해표협록소a적시공변화특정,중구결과적복상관계수R2가체도0.98,평균절대오차MAE소우0.01;해방법중구과정중무수선험신식,역조작,능구유효중구대면적성편결실혹결실비례교고적영상。
The monthly mean images of surface chlorophyll-a concentration in the Northern South China Sea (NSCS) were derived from the data preprocessing of the MODIS chlorophyll a (CHL-a) concentration Level 2 products (from January 2007 to December 2010) . And then not only does the study implement the reconstruction of missing data in the monthly mean CHL-a image using Data Interpolating Empirical Orthogonal Functions (DIEOF) , based on space-time correlation of data, but also evaluate the reconstructed result by analyzing the difference between data before and after the reconstruction, verifying the temporal and spatial variability, and calculating the precision index. The study shows that the complete MODIS CHL-a images, which are reconstructed using DIEOF, characterize the temporal and spatial variability of CHL-a in NSCS. The multiple correlation coefficient of the reconstruction result is 0.98, and the mean absolute error is less than 0.01. As it allows the calculation of missing data without requiring a prior knowledge about the error covariance structure, the DIEOF can be also successfully applied to the reconstruction of missing data in a large area or in a high proportion.