SAR Formats

Sentinel-1 SAR - SAR Formats

Products from all processing levels (Level-0, Level-1 and Level-2) are delivered in SENTINEL-SAFE format. The data delivered is packaged as a file structure containing a manifest file in XML format listing general product metadata and subfolders for measurement data, annotations, previews and support files.

Figure 1: Product Folder File Structure for Level-1 Products

The manifest file is an XML file containing the mandatory product metadata common to all SENTINEL-1 products.

Annotated data sets contain metadata describing the properties and characteristics of the measurement data or how they were generated. For each band of data there is a product annotation data set that contains metadata describing the main characteristics corresponding to that band such as the state of the platform during acquisition, image properties, polarisation, Doppler information, swath merging and geographic location. Calibration annotations contain calibration information and the beta nought, sigma nought, gamma and digital number look-up tables that can be used for absolute product calibration. Noise data annotations contain the estimated thermal noise look-up tables. Annotated data sets are provided in XML format. Level-2 products do not contain annotation data sets as all product metadata is contained within the netCDF product file.

In the preview folder, quicklook data sets are power detected, averaged and decimated to produce a lower resolution version of the image. Single polarisation products are represented with a greyscale image. Dual polarisation products are represented by a single composite colour image in RGB with the red channel (R) representing the first polarisation, the green channel (G) represents the second polarisation and the blue channel (B) represents an average of the absolute values of the two polarisations. Level-2 OCN products do not contain quicklooks.

Representation data sets found in the support folder contain information about the format or syntax of the measurement and annotated data sets and can be used to validate and exploit these data. Representation data sets are provided as XML schemas.

Measurement data sets contain the binary information of the actual acquired or processed data. For Level-0 this is the instrument data, for Level-1 it is the processed images and for Level-2 it is the derived data. There is one measurement data set per polarisation and per swath. TOPSAR SLC products contain one complex measurement dataset in GeoTIFF format per swath per polarisation. Level-1 GRD products contain one detected measurement dataset in GeoTIFF format per polarisation.

Measurement data sets are provided in GeoTIFF format for Level-1 products and netCDF format for Level-2 products. The Level-2 OCN products in netCDF format include both the annotation and measurement datasets described as netCDF attributes, dimensions and variables in one self-describing, self-contained file.

For further details on the SENTINEL-1 product formats, refer to the SENTINEL-1 Technical Guide:

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