DEA Surface Reflectance (Sentinel-2A MSI)

Version:: 3.2.1
Type:: Baseline, Raster
Resolution:: 10-60 m
Coverage:: 12 Jul 2015 to Present
Data updates:: Daily frequency, Ongoing

../../../_images/surface_reflectance_2_NBARTa_1.png

Overview

About

DEA Surface Reflectance Sentinel-2A Multispectral Instrument (MSI) is part of a suite of Digital Earth Australia’s (DEA) Surface Reflectance datasets that represent the vast archive of images which have been captured by the US Geological Survey (USGS) Landsat and European Space Agency (ESA) Sentinel-2 satellite programs, which have been validated, calibrated, and adjusted for Australian conditions — ready for easy analysis.

Access the data

For help accessing the data, see the Access tab.

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Data sources

Access the data on NCI

Data sources

View code examples

Code examples

Get via web service

Web services

Key specifications

For more specifications, see the Specifications tab.

Technical name	Geoscience Australia Sentinel-2A MSI Analysis Ready Data Collection 3
Bands	27 bands of data (nbart_coastal_aerosol, nbart_blue, and more)
DOI	10.26186/146552
Currency	See currency and the latest update date
Collection	Geoscience Australia Sentinel-2 Collection 3
Tags	geoscience_australia_sentinel_2_collection_3, analysis_ready_data, satellite_images, earth_observation, sentinel, european
Licence	Creative Commons Attribution 4.0 International Licence

Cite this product

Data citation

Geoscience Australia, 2022. Geoscience Australia Sentinel-2A MSI Analysis Ready Data Collection 3 - DEA Surface Reflectance (Sentinel-2A MSI). Geoscience Australia, Canberra. https://dx.doi.org/10.26186/146552

Publications

Li, F., Jupp, D. L. B., Reddy, S., Lymburner, L., Mueller, N., Tan, P., & Islam, A. (2010). An evaluation of the use of atmospheric and BRDF correction to standardize Landsat data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 3(3), 257–270. https://doi.org/10.1109/JSTARS.2010.2042281
Li, F., Jupp, D. L. B., Thankappan, M., Lymburner, L., Mueller, N., Lewis, A., & Held, A. (2012). A physics-based atmospheric and BRDF correction for Landsat data over mountainous terrain. Remote Sensing of Environment, 124, 756–770. https://doi.org/10.1016/j.rse.2012.06.018

Description

Background

The European Space Agency (ESA) has operated medium resolution satellites - Sentinel-2 series (Sentinel-2A and Sentinel-2B) since 2015. The spectral bands and spatial resolution of Sentinel-2 are similar to those of the Landsat series, but Sentinel-2 has a higher revisit frequency and spatial coverage. A combination of Sentinel-2 and Landsat data can provide good spatial and temporal coverage of the Earth’s surface and provide useful information to monitor environmental resources over time, such as agricultural production and mining activities. However, the raw remotely sensed data received by these satellites in the solar spectral range do not directly characterise the underlying reflectance of surface objects. The data are modified by the atmosphere, variation of solar and sensor positions as well as surface anisotropic conditions. To make accurate comparisons of imagery acquired at different times, seasons and geographic locations, and detect the change of surface, it is necessary to remove/reduce these effects to ensure the data are consistent and can be compared over time.

What this product offers

This product takes Sentinel-2A imagery captured over the Australian continent and corrects for inconsistencies across land and coastal fringes. The result is accurate and standardised surface reflectance data, which is instrumental in identifying and quantifying environmental change.

The imagery is captured using the Multispectral Instrument (MSI) sensor aboard Sentinel-2A.

This product is a single, cohesive Analysis Ready Data (ARD) package, which allows the analysis of surface reflectance data as is, without the need to apply additional corrections.

It contains two sub-products that provide corrections or attribution information:

The resolution is a 10/20/60 m grid based on the ESA Level 1C archive. Note: DEA produces NBAR as part of the Landsat ARD. This product is not produced as part of the Sentinel-2 ARD.

This Collection 3 (C3) product and has been created by reprocessing Collection 1 (C1) and making improvements to the processing pipeline and packaging. See the History tab for more details.

The introduction of a maturity concept.

The Collection 3 product is comprised of data produced to varying degrees of maturity. The maturity of a dataset is dictated by the quality of the ancillary information, such as BRDF and atmospheric data, used to generate the product. The maturity levels are Near Real Time (NRT), Interim and Final. The maturity level is designated in the filename and in the metadata.

Near Real Time (NRT) is a rapid ARD product produced < 48 hours after image capture.
Interim ARD – If there are extended delays (>18 days) in delivery of inputs to the ARD model, interim production is utilised until the issue is resolved.
Final ARD - As the higher quality ancillary datasets become available, a “Final” version of the Sentinel 2 ARD data is produced, which replaces the NRT or interim product.

Applications

This product can be used for:

The development of derivative products to monitor land, inland waterways and coastal features, such as:
- urban growth
- coastal habitats
- mining activities
- agricultural activity (e.g. pastoral, irrigated cropping, rain-fed cropping)
- water extent
The development of refined information products, such as:
- areal units of detected surface water
- areal units of deforestation
- yield predictions of agricultural parcels
Compliance surveys
Emergency management

Technical information

Multispectral Instrument (MSI)

MSI is a push-broom sensor with A Three-Mirror Anastigmat (TMA) telescope with a pupil diameter equivalent to 150 mm, isostatically mounted on the platform to minimise thermo-elastic distortions. Surface Reflectance values range between 0 and 10000. MSI collects data for visible, near infrared, and short wave infrared spectral bands.

The Analysis Ready Data concept

The Analysis Ready Data (ARD) package allows you to get up and running with your analysis as quickly as possible with minimal data preparation and additional input. This makes it simpler for you to develop applications and for the database to execute queries.

The satellite data has been processed to a minimum set of requirements and organised into a form that allows immediate analysis and interoperability through time and with other datasets. It has been adapted from CEOS Analysis Ready Data (CARD4L).

The technical report containing the data summary for the Phase 1 DEA Surface Reflectance Validation is available.

ARD sub-products

DEA Surface Reflectance NBART (Sentinel-2A MSI)

The sub-product produces standardised optical surface reflectance data using robust physical models which correct for variations and inconsistencies in the image of top atmospheric reflectance values. Corrections are performed using Nadir corrected Bidirectional reflectance distribution function Adjusted Reflectance (NBAR) with an additional terrain illumination correction applied (NBART).

DEA Surface Reflectance OA (Sentinel-2A MSI)

The NBART product depends upon the Observation Attributes (OA) product to provide accurate and reliable contextual information about the Sentinel-2B data. This ‘data provenance’ provides a chain of information which allows the data to be replicated or utilised by derivative applications. The OA takes a number of different forms, including satellite, solar and surface geometry and classification attribution labels.

Lineage

This product is derived from the ESA Sentinel-2A level 1C archive.

The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43A1 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Model Parameters dataset was provided by the National Aeronautics and Space Administration (NASA). It was produced daily using 16 days of Terra and Aqua MODIS data at 500 m resolution. See USGS: MCD43A1, NASA: MODIS BRDF / Albedo Parameter, Schaaf et al. (2002)
The ozone data was provided by Environment Canada. See Environment Canada: Global Ozone Maps
The Aerosol Optical Thickness data was provided by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). See Qin et al. (2015)
The Precipitable Water for Entire Atmosphere data was provided by the National Oceanic and Atmospheric Administration (NOAA) / Earth System Research Laboratory (ESRL) / Physical Sciences Division (PSD). See Kalnay et al. (1996)
The baseline Digital Surface Model (DSM) data produced from the Shuttle Radar Topography Mission (SRTM) was provided by the National Geospatial-Intelligence Agency (NGA). See NGA: SRTM, NASA: SRTM
Level 1C Collection 1 data was provided by the European Space agency’s Copernicus data hub, see https://scihub.copernicus.eu/

Processing steps

Software

References

Berk, A., Conforti, P., Kennett, R., Perkins, T., Hawes, F., & van den Bosch, J. (2014, June 13). MODTRAN6: A major upgrade of the MODTRAN radiative transfer code (M. Velez-Reyes & F. A. Kruse, Eds.). https://doi.org/10.1117/12.2050433

Dymond, J. R., & Shepherd, J. D. (1999). Correction of the topographic effect in remote sensing. IEEE Transactions on Geoscience and Remote Sensing, 37(5), 2618–2619. https://doi.org/10.1109/36.789656

Hudson, S. R., Warren, S. G., Brandt, R. E., Grenfell, T. C., & Six, D. (2006). Spectral bidirectional reflectance of Antarctic snow: Measurements and parameterization. Journal of Geophysical Research, 111(D18), D18106. https://doi.org/10.1029/2006JD007290

Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., & Gandin, L. et al. (1996). The NCEP/NCAR 40-Year Reanalysis Project. Bulletin Of The American Meteorological Society, 77(3), 437-471. https://doi.org/10.1175/1520-0477(1996)077<0437:tnyrp>2.0.co;2

Li, F., Jupp, D. L. B., Reddy, S., Lymburner, L., Mueller, N., Tan, P., & Islam, A. (2010). An evaluation of the use of atmospheric and brdf correction to standardize landsat data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 3(3), 257–270. https://doi.org/10.1109/JSTARS.2010.2042281

Li, F., Jupp, D. L. B., Thankappan, M., Lymburner, L., Mueller, N., Lewis, A., & Held, A. (2012). A physics-based atmospheric and BRDF correction for Landsat data over mountainous terrain. Remote Sensing of Environment, 124, 756–770. https://doi.org/10.1016/j.rse.2012.06.018

Qin, Y., Mitchell, R., & Forgan, B. W. (2015). Characterizing the aerosol and surface reflectance over Australia using AATSR. IEEE Transactions on Geoscience and Remote Sensing, 53(11), 6163–6182. https://doi.org/10.1109/TGRS.2015.2433911

Schaaf, C., Gao, F., Strahler, A., Lucht, W., Li, X., & Tsang, T. et al. (2002). First operational BRDF, albedo nadir reflectance products from MODIS. Remote Sensing Of Environment, 83(1-2), 135-148. https://www.doi.org/10.1016/s0034-4257(02)00091-3

SZA. (2011). Retrieved May 2019, from http://sacs.aeronomie.be/info/sza.php

Zhu, Z., Wang, S., & Woodcock, C. (2015). Improvement and expansion of the Fmask algorithm: cloud, cloud shadow, and snow detection for Landsats 4–7, 8, and Sentinel 2 images. Remote Sensing Of Environment, 159, 269-277. https://doi.org/10.1016/j.rse.2014.12.014

Zhu, Z., & Woodcock, C. E. (2012). Object-based cloud and cloud shadow detection in Landsat imagery. Remote Sensing of Environment, 118, 83–94. https://doi.org/10.1016/j.rse.2011.10.028

Quality

Accuracy

For detailed information on accuracy and limitations, refer to the sub-products’ pages

Quality assurance

For detailed information on quality assurance, refer to the sub-products’ pages

Specifications

Bands

Bands are distinct layers of data within a product that can be loaded using the Open Data Cube (on the DEA Sandbox or NCI) or DEA’s STAC API. Here are the bands of the product: ga_s2am_ard_3.

	Aliases	Resolution	No-data	Units	Type	Description
nbart_coastal_aerosol	nbart_band01 coastal_aerosol	60	-999	-	int16	-
nbart_blue	nbart_band02 blue	10	-999	-	int16	-
nbart_green	nbart_band03 green	10	-999	-	int16	-
nbart_red	nbart_band04 red	10	-999	-	int16	-
nbart_red_edge_1	nbart_band05 red_edge_1	20	-999	-	int16	-
nbart_red_edge_2	nbart_band06 red_edge_2	20	-999	-	int16	-
nbart_red_edge_3	nbart_band07 red_edge_3	20	-999	-	int16	-
nbart_nir_1	nbart_band08 nir_1 nbart_common_nir	10	-999	-	int16	-
nbart_nir_2	nbart_band8a nir_2	20	-999	-	int16	-
nbart_swir_2	nbart_band11 swir_2 nbart_common_swir_1 swir2	20	-999	-	int16	-
nbart_swir_3	nbart_band12 swir_3 nbart_common_swir_2	20	-999	-	int16	-
oa_fmask	fmask	20	0	-	uint8	-
oa_nbart_contiguity	nbart_contiguity	10	255	-	uint8	-
oa_azimuthal_exiting	azimuthal_exiting	20	NaN	-	float32	-
oa_azimuthal_incident	azimuthal_incident	20	NaN	-	float32	-
oa_combined_terrain_shadow	combined_terrain_shadow	20	255	-	uint8	-
oa_exiting_angle	exiting_angle	20	NaN	-	float32	-
oa_incident_angle	incident_angle	20	NaN	-	float32	-
oa_relative_azimuth	relative_azimuth	20	NaN	-	float32	-
oa_relative_slope	relative_slope	20	NaN	-	float32	-
oa_satellite_azimuth	satellite_azimuth	20	NaN	-	float32	-
oa_satellite_view	satellite_view	20	NaN	-	float32	-
oa_solar_azimuth	solar_azimuth	20	NaN	-	float32	-
oa_solar_zenith	solar_zenith	20	NaN	-	float32	-
oa_time_delta	time_delta	20	NaN	-	float32	-
oa_s2cloudless_mask	s2cloudless_mask	60	0	-	uint8	-
oa_s2cloudless_prob	s2cloudless_prob	60	NaN	-	float64	-

For all ‘nbart_’ bands, Surface Reflectance is scaled between 0 and 10,000.

Product information

This metadata provides general information about the product.

Product ID	ga_s2am_ard_3	Used to load data from the Open Data Cube.
Short name	DEA Surface Reflectance (Sentinel-2A MSI)	The name that is commonly used to refer to the product.
Technical name	Geoscience Australia Sentinel-2A MSI Analysis Ready Data Collection 3	The full technical name that refers to the product and its specific provider, sensors, and collection.
Version	3.2.1	The version number of the product. See the History tab.
Lineage type	Baseline	Baseline products are produced directly from satellite data.
Spatial type	Raster	Raster data consists of a grid of pixels.
Spatial resolution	10-60 m	The size of the pixels in the raster.
Temporal coverage	12 Jul 2015 to Present	The time span for which data is available.
Update frequency	Daily	The expected frequency of data updates. Also called ‘Temporal resolution’.
Update activity	Ongoing	The activity status of data updates.
Currency	See the Currency Report	Currency is a measure based on data publishing and update frequency.
Latest update date	Currency Report	See Table A of the report.
DOI	10.26186/146552	The Digital Object Identifier.
Catalogue ID	146552	The Data and Publications catalogue (eCat) ID.
Licence	Creative Commons Attribution 4.0 International Licence	See the Credits tab.

Product categorisation

This metadata describes how the product relates to other DEA products.

Collection	Geoscience Australia Sentinel-2 Collection 3
Tags	geoscience_australia_sentinel_2_collection_3, analysis_ready_data, satellite_images, earth_observation, sentinel, european

Access

Access the data

DEA Maps	See it on a map	Learn how to use DEA Maps.
DEA Explorer	DEA Explorer	Learn how to use the DEA Explorer.
Data sources	Access the data on AWS Access the data on NCI	Learn how to access the data via AWS.
Code examples	View code examples	Learn how to use the DEA Sandbox.
Web services	Get via web service	Learn how to use DEA’s web services.

History

Version history

Versions are numbered using the Semantic Versioning scheme (Major.Minor.Patch). Note that this list may include name changes and predecessor products.

v3.2.1	-	Current version
v1.0.0	of	DEA Surface Reflectance NBAR (Sentinel-2 MSI)

Changelog

This Collection 3 (C3) product and has been created by reprocessing Collection 1 (C1) and making improvements to the processing pipeline and packaging.

Packaging updates include:

Open Data Cube (ODC) eo3 metadata
metadata includes STAC fields to enable users to filter by fields such as tile ID or cloud cover percentage in applications such as ODC
additional STAC metadata file in JSON format
directory structure and file names that are consistent with Geoscience Australia’s Landsat C3 products.

Additional updates include:

upgrading the spectral response function to result in a more accurate product. These new versions include minor updates, slight changes of the central wavelengths for band B02 of S2A and S2B, and band B01 of S2B, along with slight changes of the Full Width Half Maximum (FMWH) for most of the bands
correction of solar constant errors in the conversion between reflectance and radiance as well as in the atmospheric correction
an additional cloud mask layer (s2cloudless)
removal of NBAR layers
reduced spatial resolution of observation attribute layers to 20m resolution, with the contiguity layer being maintained at 10m
additional of GQA information to dataset metadata
removal of buffering from fmask layer
BRDF ancillary upgraded from MODIS BRDF C5 to MODIS BRDF C6
Upgrading from MODTRAN 5.2 to MODTRAN 6.

Credits

Acknowledgments

This research was undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Government.

Contains modified Copernicus Sentinel data 2015-present.

The authors would like to thank the following organisations:

National Aeronautics and Space Administration (NASA)
Environment Canada
The Commonwealth Scientific and Industrial Research Organisation (CSIRO)
National Oceanic and Atmospheric Administration (NOAA) / Earth System Research Laboratories (ESRL) / Physical Sciences Laboratory (PSD)
The National Geospatial-Intelligence Agency (NGA)
The United States Geological Survey (USGS) / Earth Resources Observation and Science (EROS) Center
Spectral Sciences Inc.

License and copyright

Released under Creative Commons Attribution 4.0 International Licence.