International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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Volume XLII-4/W19
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-4/W19, 125–132, 2019
https://doi.org/10.5194/isprs-archives-XLII-4-W19-125-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-4/W19, 125–132, 2019
https://doi.org/10.5194/isprs-archives-XLII-4-W19-125-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

  23 Dec 2019

23 Dec 2019

ESTIMATION OF CHLOROPHYLL-A CONCENTRATION IN LAGUNA DE BAY USING SENTINEL-3 SATELLITE DATA

M. Conopio1, R. K. Japor1, A. C. Blanco1,2, and A. M. Tamondong1,2 M. Conopio et al.
  • 1Department of Geodetic Engineering, University of the Philippines – Diliman, Quezon City 1101, Philippines
  • 2Training Center for Applied Geodesy and Photogrammetry, University of the Philippines – Diliman, Quezon City 1101, Philippines

Keywords: OLCI, Laguna Lake, Regression Model, Water Quality, Microalgae

Abstract. The mission of the European Space Agency’s Sentinel-3 satellite is to provide data for land and ocean monitoring purposes. Sentinel- 3’s Ocean and Land Colour Instrument (OLCI) data are being used largely for monitoring offshore and coastal waters but can also be used for inland waters including lakes. It has a spatial resolution of 300 meters, a temporal resolution of 2–3 days and contains 21 spectral bands. Laguna de Bay, with a surface area of around 930 km2, suffers from periodic algal blooms resulting from excessive nutrient inputs from surrounding watersheds. This study aims to assess the applicability of Sentinel-3 OLCI for estimating chlorophylla (chl-a) concentration in Laguna Lake. Several chl-a estimation algorithms (i.e., band ratios and indices) were tested for Sentinel 3 OLCI images and compared with in-situ data obtained using a chl-a sensor. A regression model comprising of individual spectral bands, band ratios, and band indices for chl-a estimation as independent variables was developed, yielding an adjusted R2 of 0.759 and RMSE of 1.19 ug/L. The model consists of R620, R674/R708, and RED/NIR. A map was produced showing the spatial distribution of chl-a in Laguna Lake, with most of the portion of the lake having a concentration ranging from 7.5 ug/L to 15 ug/L. This shows that Sentinel 3 OLCI images can be utilized for accurately estimating chl-a in Laguna Lake.