Retrieval of total inorganic nitrogen concentration in pearl river estuary by remote sensing
珠江口海域总无机氮的遥感提取研究

In this paper, an algorithm for retrieval of Total Inorganic Nitrogen (TIN) concentration was developed by Partial Least Squares (PLS) regression, based on the remote sensing reflectance data and TIN data measured at 36 stations in Pearl River Estuary during two cruises which were conducted in January 2003 and January 2004 respectively. Six cases of band-ratio were considered on the algorithm development, and the band-ratio with band 6 as the denominator was used for the algorithm. The estimated TIN concentration was compared with sea-truth TIN data at 18 stations in the Pearl River estuary. The average relative error is 9.06%, and maximum relative error is 18.2%. Then the algorithm was also applied to SeaWiFS data of Dec., 31, 1998. The SeaWiFS-retrieved TIN results were compared with measured TIN data, which were collected in Dec., 31, 1998 and the average relative error is 31.9%. The result shows that the algorithm has good stability, and could be applied to satellite data acquired in different time. The algorithm could be employed for estimation of TIN concentration and for research of eutrophication in the Pearl River estuary.