The Sentinel-3 Synergy Level-2 SDR (Surface Directional Reflectance) product provides the atmospherically corrected surface bi-directional reflectance, also termed surface directional reflectance (SDR), and the corresponding information on aerosol properties. It is generated from Sentinel-3 SLSTR and OLCI TOA (Top-of-atmosphere) radiances using the enhanced spectral and angular capabilities of a combined instrument.
The contents of the processing baseline (PB) releases are tracked and described at Sentinel-3 Synergy Processing Baseline.
Figure 1 SY_2_SYN product sample
SY_2_SYN Dataset Specification
The Sentinel-3 Synergy Level-2 product provides atmospherically corrected bi-directional surface reflectances. Aerosol Optical Thickness (T550) and Angstrom exponent (A500) at 550 nm, classification and quality flags are included as additional parameters in the product. The main characteristics of the SY_2_SYN products are listed in Table 2.
Table 2 SY_2_SYN Product Characteristics
Product name |
SY_2_SYN |
High-level description |
Atmospherically corrected bi-directional surface reflectances of 5 solar reflective SLSTR bands at both nadir and forward views (a total of 10 input channels – S4 channel is excluded as this band is dedicated to cloud detection), and 16 OLCI bands at all non‐absorbing channels (i.e. excluding OLCI oxygen bands 13 to 15 and water vapour bands 19 and 20) |
Algorithm used |
SYN SDR Algorithm |
Data Characteristics |
|
Additional layers |
|
DEM used |
Digital Elevation Model (DEM) GETASSE30 30 seconds of resolution |
Auxiliary Data used |
|
Production & Distribution |
Systematic generation and online distribution |
Data Volume |
About 600 MB (each 1270 x 1270 km) |
Data Availability |
Global since October 2018 |
Data Delivery |
Available within 48 hours after data acquisition |
Learn more about the Sentinel-3 Synergy Level-2 algorithm in the ATBD.
Resolution
The SYN Level-2 User products are produced at OLCI full resolution (300 m), taking into account only the daylight part of the orbit and pixels over land.
The temporal coverage is less than 2 days with two satellites in orbit.
The radiometric resolution depends on the OLCI and SLSTR bands used in the Synergy product, more details are available here.
Download the relevant Sentinel-3 OLCI and SLSTR spectral responses.
Coverage acquisition maps
The Sentinel-3 mission provides systematic Synergy L2 global coverage over land. The swath corresponds to the common part of the OLCI and SLSTR nadir view swaths for the daylight part of the SENTINEL-3 orbit, i.e. the entire OLCI swath: ~1 270 km. Read more about Coverage.
Quality reports
The Optical Mission Performance Centre (OPT-MPC) provides a monthly status of the Sentinel-3 synergy product quality via the dissemination of a Sentinel-3 OLCI Data Quality Report (DQR). The report provides information on the most recent product performance validation results and the processing baseline version in operation.
View available Sentinel-3 OLCI Data Quality Report.
How to access this data
Products are freely available via the Copernicus Open Access Hub. In addition to the download services, the Sentinel Data Products are available in the Copernicus Data and Information Access Service (DIAS) cloud environments. Each DIAS provides processing resources, tools and complimentary data sources at commercial conditions to further facilitate the access to Sentinel data. Learn more about how to access Sentinel data.
Resources
- Synergy Level 2 ATBD
- Sentinel-3 Product Data Format Specification - Synergy Level 1 and 2
- Sentinel-3 Synergy Level 2 product type
- Copernicus Sentinel-3 SYN Land User Handbook
- Sentinel-3, Altimetry, OLCI, SLSTR, Synergy, Metadata Specification
- Sentinel-3 Synergy naming conventions
Tools
The Sentinel-3 Toolbox consists of a rich set of visualisation, analysis and processing tools for the exploitation of Sentinel-3 Synergy products.
Data Citation Guidelines
Users, who, in their research, use ESA Earth Observation data that have been assigned a DOI, are asked to use it when citing the data source in their publications: European Space Agency, 2022, Level-2 SYNergy Surface Directional Reflectance, Version Collection version 2, https://doi.org/10.5270/S3D-643ee90.