A Simple Band-ratio Algorithm to Assess Suspended Particulate Matter from Remote Sensing Over Coastal and Inland Waters of Vietnam: Application to the VNREDSat-1/NAOMI Sensor
| Autor: | Xavier Mériaux, Hubert Loisel, Huong Le Thi, Hai Le Vu Hong, Ngoc Nguyen Minh, Dat Dinh Ngoc, Charles Verpoorter, Thao Nguyen Van, Vincent Vantrepotte, Huy Chu Xuan, Hanh Pham Thi Minh |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
lcsh:Hydraulic engineering
010504 meteorology & atmospheric sciences Geography Planning and Development Remote sensing reflectance 0207 environmental engineering 02 engineering and technology Aquatic Science 01 natural sciences Biochemistry lcsh:Water supply for domestic and industrial purposes lcsh:TC1-978 14. Life underwater oceanography 020701 environmental engineering Image resolution 0105 earth and related environmental sciences Water Science and Technology Remote sensing VNREDSat-1/NAOMI Polynomial regression SIMPLE (dark matter experiment) lcsh:TD201-500 algorithm Atmospheric correction Suspended particulate matter Spectral bands Particulates suspended particulate matter 6. Clean water Data point Remote sensing (archaeology) Environmental science Landsat-8/OLI Band ratio Algorithm |
| Zdroj: | Water Volume 12 Issue 9 Water, Vol 12, Iss 2636, p 2636 (2020) Water (2073-4441) (MDPI AG), 2020, Vol. 12, N. 9, P. 2636 (16p.) |
| Popis: | VNREDSat-1 is the first Vietnamese satellite enabling the survey of environmental parameters, such as vegetation and water coverages or surface water quality at medium spatial resolution (from 2.5 to 10 m depending on the considered channel). The New AstroSat Optical Modular Instrument (NAOMI) sensor on board VNREDSat-1 has the required spectral bands to assess the suspended particulate matter (SPM) concentration. Because recent studies have shown that the remote sensing reflectance, Rrs(&lambda ), at the blue (450&ndash 520 nm), green (530&ndash 600 nm), and red (620&ndash 690 nm) spectral bands can be assessed using NAOMI with good accuracy, the present study is dedicated to the development and validation of an algorithm (hereafter referred to as V1SPM) to assess SPM from Rrs(&lambda ) over inland and coastal waters of Vietnam. For that purpose, an in-situ data set of hyper-spectral Rrs(&lambda ) and SPM (from 0.47 to 240.14 g· m&minus 3) measurements collected at 205 coastal and inland stations has been gathered. Among the different approaches, including four historical algorithms, the polynomial algorithms involving the red-to-green reflectance ratio presents the best performance on the validation data set (mean absolute percent difference (MAPD) of 18.7%). Compared to the use of a single spectral band, the band ratio reduces the scatter around the polynomial fit, as well as the impact of imperfect atmospheric corrections. Due to the lack of matchup data points with VNREDSat-1, the full VNREDSat-1 processing chain (atmospheric correction (RED-NIR) and V1SPM), aiming at estimating SPM from the top-of-atmosphere signal, was applied to the Landsat-8/OLI match-up data points with relatively low to moderate SPM concentration (3.33&ndash 15.25 g· 3), yielding a MAPD of 15.8%. An illustration of the use of this VNREDSat-1 processing chain during a flooding event occurring in Vietnam is provided. |
| Databáze: | OpenAIRE |
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