Next Article in Journal
Profiling Dust Mass Concentration in Northwest China Using a Joint Lidar and Sun-Photometer Setting
Next Article in Special Issue
Interannual and Seasonal Variations of Hydrological Connectivity in a Large Shallow Wetland of North China Estimated from Landsat 8 Images
Previous Article in Journal
Recent Advancement in Remote Sensing Technology for Hydrology Analysis and Water Resources Management
Previous Article in Special Issue
Assessment of Annual Composite Images Obtained by Google Earth Engine for Urban Areas Mapping Using Random Forest
Technical Note

Google Earth Engine Sentinel-3 OLCI Level-1 Dataset Deviates from the Original Data: Causes and Consequences

Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, 7500 AE Enschede, The Netherlands
*
Author to whom correspondence should be addressed.
Academic Editor: Koreen Millard
Received: 4 February 2021 / Revised: 8 March 2021 / Accepted: 10 March 2021 / Published: 13 March 2021
In this study, we demonstrate that the Google Earth Engine (GEE) dataset of Sentinel-3 Ocean and Land Color Instrument (OLCI) level-1 deviates from the original Copernicus Open Access Data Hub Service (DHUS) data by 10–20 W m2 sr1μμm1 per pixel per band. We compared GEE and DHUS single pixel time series for the period from April 2016 to September 2020 and identified two sources of this discrepancy: the ground pixel position and reprojection. The ground pixel position of OLCI product can be determined in two ways: from geo-coordinates (DHUS) or from tie-point coordinates (GEE). We recommend using geo-coordinates for pixel extraction from the original data. When the Sentinel Application Platform (SNAP) Pixel Extraction Tool is used, an additional distance check has to be conducted to exclude pixels that lay further than 212 m from the point of interest. Even geo-coordinates-based pixel extraction requires the homogeneity of the target area at a 700 m diameter (49 ha) footprint (double of the pixel resolution). The GEE OLCI dataset can be safely used if the homogeneity assumption holds at 2700 m diameter (9-by-9 OLCI pixels) or if the uncertainty in the radiance of 10% is not critical for the application. Further analysis showed that the scaling factors reported in the GEE dataset description must not be used. Finally, observation geometry and meteorological data are not present in the GEE OLCI dataset, but they are crucial for most applications. Therefore, we propose to calculate angles and extraterrestrial solar fluxes and to use an alternative data source—the Copernicus Atmosphere Monitoring Service (CAMS) dataset—for meteodata. View Full-Text
Keywords: Google earth engine; GEE; Sentinel-3; ocean and land color instrument; OLCI; medium resolution imaging spectrometer; MERIS; Copernicus open access data hub service; DHUS; European Space Agency; ESA; pixel uncertainty; SNAP; time series; Copernicus atmosphere monitoring service; CAMS Google earth engine; GEE; Sentinel-3; ocean and land color instrument; OLCI; medium resolution imaging spectrometer; MERIS; Copernicus open access data hub service; DHUS; European Space Agency; ESA; pixel uncertainty; SNAP; time series; Copernicus atmosphere monitoring service; CAMS
Show Figures

Figure 1

MDPI and ACS Style

Prikaziuk, E.; Yang, P.; van der Tol, C. Google Earth Engine Sentinel-3 OLCI Level-1 Dataset Deviates from the Original Data: Causes and Consequences. Remote Sens. 2021, 13, 1098. https://0-doi-org.brum.beds.ac.uk/10.3390/rs13061098

AMA Style

Prikaziuk E, Yang P, van der Tol C. Google Earth Engine Sentinel-3 OLCI Level-1 Dataset Deviates from the Original Data: Causes and Consequences. Remote Sensing. 2021; 13(6):1098. https://0-doi-org.brum.beds.ac.uk/10.3390/rs13061098

Chicago/Turabian Style

Prikaziuk, Egor, Peiqi Yang, and Christiaan van der Tol. 2021. "Google Earth Engine Sentinel-3 OLCI Level-1 Dataset Deviates from the Original Data: Causes and Consequences" Remote Sensing 13, no. 6: 1098. https://0-doi-org.brum.beds.ac.uk/10.3390/rs13061098

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop