Retrieval of total suspended matter concentration from Gaofen-1 Wide Field Imager (WFI) multispectral imagery with the assistance of Terra MODIS in turbid water - case in Deep Bay

• Published in: International journal of remote sensing Vol. 37; no. 14; pp. 3400 - 3413
• Main Authors: Tian, Liqiao, Wai, Onyx W. H., Chen, Xiaoling, Li, Wenbo, Li, Jian, Li, Wenkai, Zhang, Haidong
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 17.07.2016
• Subjects: Case depth; Construction; MODIS; Monitoring; Reflectance; Reflectivity; Remote sensing; Retrieval; ISEW, China, People's Rep., Hong Kong, New Terr., Deep Bay; China, People's Rep
• ISSN: 0143-1161; 1366-5901
• DOI: 10.1080/01431161.2016.1199084

This study proposed a method for developing high spatial resolution Gaofen-1 satellite (GF-1) Wide Field Imager (WFI)-based total suspended matter concentration (C TSM ) retrieval model with the assistance of Moderate Resolution Imaging Spectroradiometer (MODIS) data, using the Deep Bay in China as a case. Based on long-term calibrated C TSM measurements of optical backscatter (OBS) 3A turbidity and temperature monitoring system of two stationary stations from January 2007 through November 2008, 33 match-ups were selected to build an exponential retrieval model for MODIS atmospherically corrected remote-sensing reflectance (R rs ) ratio (R rs,645 /R rs,555 ). Validation of the MODIS model showed well agreement with the seven in situ C TSM measurements with a root mean squared error (RMSE) of 5.06 mg l − 1 and a coefficient of determination R 2 of 0.80. Aided with six MODIS retrieved C TSM products, different band combinations (single band (R rc,660 ), band subtraction (R rc,660 -R rc,560 ), band ratio (R rc,660 /R rc,560 ), and total suspended matter index at 660 nm band (TSMI 660 ) were evaluated for simultaneous GF-1 WFI Rayleigh-corrected reflectance (R rc ). The results showed that the exponential model based on the Rayleigh-corrected reflectance ratio (R rc,660 /R rc,560 ) could achieve acceptable accuracy, with RMSE of 14.80 mg l − 1 and R 2 of 0.62. The proposed method would be helpful for dynamic monitoring in the Deep Bay, and more important could also provide an alternative approach for studies when in situ measurements are unreachable.