Sentinel-2

Long name Sentinel-2
Short name STN2
Sensor type Optical
Platform Sentinel-2
Key file name (use to open data set) MTD_*.xml, S2A_OPER*.xml, or manifest.safe
Supported file extensions *.xml, *.jp2, *.png
Sections

Data product name and description
Distribution disk files
Returned data for supported format
References

Data product name and description

Sentinel-2 is two identical satellites flying in a single orbit as Sentinel-2A and Sentinel-2B. It carries an optical-instrument payload that samples 13 spectral bands at various resolutions:
  • Four bands at 10 meter spatial resolution
  • Six bands at 20 meter spatial resolution
  • Three bands at 60 meter spatial resolution
The maximum image dimensions are equal to 290 kilometers across-track for all products.
Note: The information provided herein is based on the data distributor's documentation cited under References.

Spectral bands:
Spectral range (nm)

Spatial resolution (m)*

Maximum image dimensions
(Across track x along track, km)

Notes

B2 (Blue): 457 - 523
B3 (Green): 542 - 578
B4 (Red): 650 - 680
B8 (NIR): 784 - 900
B5 (Vegetation Red Edge): 697 - 713
B6 (Vegetation Red Edge): 732 - 748
B7 (Vegetation Red Edge): 773 - 793
B8a (NIR): 855 - 875
B11 (SWIR): 1565 - 1655
B12 (SWIR): 2100 - 2280
B1 (Coastal Aerosol): 433 - 453
B9 (Water Vapour): 935 - 955
B10 (SWIR Cirrus): 1365 - 1395

10 (B2, B3, B4, B8)
20 (B5, B6, B7, B8a, B11, B12)
60 (B1, B9, B10)

≈290 (across track) N/A

* Resolution is always nadir position unless noted otherwise.

Sentinel-2 is processed at various levels (Level 0, Level 1A, Level 1B and Level 1C); however, only Level 1C and Level 2A are available widely.

Processing level Horizontal accuracy (m) Description/notes
1C ≈12.5 (after image processing with control points) Level 1C products are created by using a digital elevation model (DEM) to project the image in cartographic coordinates.

Level 1C processing includes radiometric and geometric corrections that include orthorectification and spatial registration according to a global reference system with subpixel accuracy.

Per-pixel radiometric measurements are provided in top-of-atmosphere (TOA) reflectances with all parameters to convert the pixels into radiances.

2A ≈12.5 (after image processing with control points) Level 2A processing consists of scene classification and atmospheric correction applied to Level-1C ortho-image products.

Level-2A data is a bottom-of-atmosphere (BOA) reflectance ortho-image product.

Additional output products include:
  • [AOT] Aerosol optical thickness map
  • [CLD] Cloud confidence map
  • [SCL] Scene classification map
  • [SNW] Snow/ice confidence map
  • [WVP] Scene-average water-vapour map

Distribution disk files

GDB retrieves four, six, or three bands as three separate groups of image channels in multispectral data grouped by resolution (10 meter, 20 meter, and 60 meter).

Each band is assembled from a list of tiles (known as granules). On opening the data set, depending on the program you use, you may be prompted to select the group of image channels that you want. When all of the product data is in two UTM zones, you may also be prompted to select a zone number. You can select a specific zone with which to load the image bands.

To open a data set in CATALYST Professional Focus
  1. In the File Selector window, at the first level of the product package, select the key file name.

    That is, select a key file (MTD_*.xml, S2A_OPER*.xml, or manifest.safe.

  2. When prompted, select a UTM zone, and then select one or more groups of image channels, as applicable.
To open a data set in CATALYST Professional EASI or Python
  • Specify the file name, UTM zone (if more than one), and the image-channel group.
    For example:
    Fili="<path><key_file_name>:Band Resolution:10M"
    Fili="<path><key_file_name>:Band Resolution:20M"
    Fili="<path><key_file_name>:Band Resolution:60M"
    Fili="<path><key_file_name>-UTM55:Band Resolution:10M"
    Fili="<path><key_file_name>-UTM56:Band Resolution:10M"
    					

If the file name is appended with neither a zone nor a resolution, GDB will use the default value. The default value for the UTM zone is the first zone or if there is only one zone, none. The default value for the band resolution is 10 meters.

In cases in which certain granules are missing or damaged, incomplete zones will not be displayed in the band-selection list and only complete zones will be available for display.

Warning: Data sets for this sensor are organized in a specific folder structure on disk. GDB uses this structure and the file names to identify the data product type. Do not alter the folder structure or any file names prior to data ingestion to ensure the image data and auxiliary information are imported correctly.
Note: In CATALYST Professional programs, bands are not resampled at the same resolution (such as with ESA SNAP). Only bands of the same resolution are displayed; however, in Focus, you can manually load bands of different resolution into the same project.
File name Format Required Contents/details
AUX_DATA Folder No Contains set of auxiliary files that can be embedded in the product structure, if selected during download.
DATASTRIP Folder Yes Multiple folders, each corresponding to the data strip that comprises the product and identified by proper PDI_ID (Datastrip_ID).
Contains:
  • QI_DATA
    • *.xml (metadata file at tile level)
  • *.xml (metadata file at tile level)
GRANULE Folder Yes Multiple folders, each corresponding to the tiles that comprise the product and identified by proper PDI_ID (Tile_ID).
  • AUX_DATA
    • *.file (auxiliary file data)
  • IMG_DATA
    • *.jp2 (image file, one file per spectral band)
  • *.xml (metadata file at tile level)
HTML Folder No Contains data used for documents supplied by the vendor.
rep_info Folder No Contains metadata (*.xsd).
INSPIRE.xml Extensible Markup Language No Metadata file based on INSPIRE metadata regulation.
manifest.safe Safe No Product annotations. This is a key file you can use to open the data set.
*.png Portable Network Graphic Optional Thumbnail image.
MTD_*.xml (formerley S2*.xml) Extensible Markup Language Yes Key file name. Use this file to open the data set.

Returned data for supported format

Sentinel-2 data can be opened directly in its raw vendor format or imported into a PCIDSK (*.pix) file by using the key file name (MTD_*.xml, S2A_OPER*.xml, or manifest.safe). For optimal processing, use the PCIDSK format.

The data structure of the data, after it is opened by GDB, is as described in the following tables.

Data product Data returned Details
Level 1C: 10 meter

4 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

The main product XML file [TEX] is read as the first text segment.

<No_granule> refers to the number of granules. Metadata of each granule is imported in a separate text file [TEX].

Level 1C: 20 meter

6 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

The main product XML file [TEX] is read as the first text segment.
Level 1C: 60 meter

3 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

The main product XML file [TEX] is read as the first text segment.
Level 2A: 10 meter

6 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

Contains:
  • Bands B2, B3, B4, B8
  • AOT, WVP maps

The main product XML file [TEX] is read as the first text segment.

Level 2A: 20 meter

14 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

Contains:
  • Resampled 10 meter bands B2, B3, B4, B8
  • 20 meter bands B5, B6, B7, B11, B12
  • SCL, SNW, CLD, AOT, and WVP maps

The main product XML file [TEX] is read as the first text segment.

Level 2A: 60 meter

16 x [16U] raster channels
[TEX] metadata file (mtd_msil1c.xml)
<No_granule> x [TEX] tile-metadata file

Contains:
  • Resampled 10 meter bands B2, B3, B4, B8
  • Resampled 20 meter bands B5, B6, B7, B11, B12
  • 60 meter bands B1, B9
  • SCL, SNW, CLD, AOT, and WVP maps

The main product XML file [TEX] is read as the first text segment.

References

Copernicus: Sentinel-2, Sharing Earth Observation Records, eoPortal Directory. European Space agency (ESA).

For more information, visit: Earth Observation Portal

Vendor supplied documentation: Products Specification Document (PSD).pdf

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