Sentinel-1 GRD

About Sentinel-1 GRD Data

Mission Information

The Sentinel-1 imagery is provided by two polar-orbiting satellites, operating day and night performing C-band synthetic aperture radar imaging, enabling them to acquire imagery regardless of the weather. Main applications are for monitoring sea ice, oil spills, marine winds, waves & currents, land-use change, land deformation among others, and to respond to emergencies such as floods and earthquakes.

Sentinel Hub currently supports Sentinel-1 Level-1 GRD (Ground Range Detected) products only. See other Sentinel-1 products offered by ESA.

Observation Scenarios

Observation scenario defines the acquisition mode and polarization with which the Sentinel-1 will acquire data over certain area. When searching for the data the observation scenario can be helpful when selecting a combination of values of different parameters. Below is an example of observation scenario but it may vary through time depending on requirements. The full archive of observation scenarios is available.


(Source ESA)

More information:

Attribution and Use

The Sentinel products are released under the license available here.

Processing Chain

The following describes the way Sentinel-1 GRD data is processed in Sentinel Hub. For information on how to set processing parameters, see Processing Options.

  1. Original or multilooked source chosen (depending on the resolution level; multilooking is done in ground range. Also see.)
  2. Calibration to the chosen backscatter coefficient and thermal noise removal applied.
  3. (Optional) Radiometric terrain correction using Flattening gamma is performed. The Mapzen or Copernicus DEM is used (see the example).
  4. (Optional) Orthorectification using Range-Doppler terrain correction using the Mapzen or Copernicus DEM.


  • The orbit files used are the ones bundled in the products themselves. We find these more than sufficient for GRD use. Non-realtime products typically contain restituted orbit information.
  • The areas of border noise are not displayed by Sentinel Hub.
  • No speckle filtering is applied at any stage. However, you can do multitemporal averaging to reduce speckle.
  • Radiometric terrain correction can only be performed if orthorectification is enabled. The DEM oversampling parameter is by default set to 2 and can be user adjusted. For low resolution requests (many meters per pixel) increasing it to 3, for example, can be worthwhile to reduce artifacts. Integer values are recommended. See also the S1GRD API Reference.
  • The DEM, if used, is resampled using bilinear interpolation, and the same DEM is used for both radiometric terrain correction and orthorectification, provided both are enabled.

Accessing Sentinel-1 GRD Data

To access data you need to send a POST request to our process API. The requested data will be returned as the response to your request. Each POST request can be tailored to get you exactly the data you require. To do this requires setting various parameters which depend on the data collection you are querying. This chapter will help you understand the parameters for S1GRD data. To see examples of such requests go here, and for an overview of all API parameters see the S1GRD API Reference.

Endpoint Locations

ServiceNotes since October 2014 since October 2014 policy of 48 months for Europe
Rolling policy of 12 months for World

Differences in Capabilities

  • Zoom out:

    • @ : Zooming out will use multi-looked sources at an appropriate resolution to your viewing level. You can therefore expect high quality results at all zoom levels.
    • @ : Zooming out will use multi-looked sources at an appropriate resolution to your viewing level. You can therefore expect high quality results at all zoom levels.
    • @ : Zooming out will NOT use multi-looked sources. Zooming out is therefore more of a convenience preview as the images will be excessively noisy. If this is an issue consider using the AWS service instead.
  • Backscatter coefficient:

    • @ : We support all backscatter coefficients.
    • @ : We support all backscatter coefficients.
    • @ : We support gamma0 backscatter coefficient (GAMMA0_ELLIPSOID). Radiometric terrain correction is not supported.

Data type identifier: sentinel-1-grd

Use sentinel-1-grd (previously S1GRD) as the value of the parameter in your API requests. This is mandatory and will ensure you get Sentinel-1 GRD data.

Filtering Options

This chapter will explain the object of the S1GRD process API.


The same as for S2L1C.

resolution (pixel spacing)

HIGH10m/px for IW and 25m/px for EW
MEDIUM40m/px for IW and EW

A full table of resolutions is available (here)


Sentinel-1 operates in four different acquisition modes (more).

ValueDescriptionPolarization options
SMStripmap mode (more ).HH+HV, VV+VH, HH, VV
IWInterferometric Wide (IW) swath mode (more ).HH+HV, VV+VH, HH, VV
EWExtra Wide (EW) swath mode (more ).HH+HV, VV+VH, HH, VV
WVWave mode (more ).HH, VV


This table contains information about the polarization two letter code used by ESA and the product's contained polarizations.

DHHH+HVTypical for EW acquisitions
DVVV+VHTypical for IW acquisitions
HHPartial Dual, HH onlyHH+HV was acquired, only HH is available in this product
HVPartial Dual, HV onlyHH+HV was acquired, only HV is available in this product
VVPartial Dual, VV onlyVV+VH was acquired, only VV is available in this product
VHPartial Dual, VH onlyVV+VH was acquired, only VH is available in this product


ASCENDINGData acquired when the satellite was traveling approx. towards the Earth's North pole.
DESCENDINGData acquired when the satellite was traveling approx. towards the Earth's South pole.



Processing Options

This chapter will explain the object of the S1GRD process API.

upsamplingThe same as for S2L1C.
downsamplingThe same as for S2L1C.
backCoeffBackscatter coefficientBETA0
orthorectify [2]Enables/disables orthorectificationTRUE - Orthorectified
FALSE - non-Orthorectified
TRUE on EOCloud, FALSE on AWS and Mundi
demInstanceSelects DEM instance.MAPZEN - Mapzen DEM
COPERNICUS - Copernicus DEM 10m and 30m [3]
COPERNICUS_30 - Copernicus DEM 30m [4]
COPERNICUS_90 - Copernicus DEM 90m

[1]: Gamma0_ellipsoid and sigma0_ellipsoid use an ellipsoid earth model. Radiometric terrain correction can be enabled by setting the backscatter coefficient to gamma0_terrain; orthorectification must be enabled in this case.

[2]: For orthorectification, we use the DEM instance specified in demInstance field or Mapzen DEM by default. The Copernicus DEM is generally of higher quality and recommended in most cases. The non-orthorectified products use a simple earth model as provided in the products themselves. This may be sufficient for very flat target areas and is faster to process.

[3]: It has 10m resolution inside the EEA-10 extent and 30m elsewhere.

[4]: The Copernicus 30m DEM has global coverage if used for the processing of Sentinel-1 data.

Available Bands and Data

Information in this chapter is useful when defining input object in evalscript. Any string listed in the column Name can be an element of the input.bands array in your evalscript.

VVPresent when the product polarization type is one of SV, DV or VV.
VHPresent when the product polarization type is VH or DV.
HVPresent when the product polarization type is HV or DH.
HHPresent when the product polarization type is one of SH, DH or HH.
localIncidenceAngleThe local incidence angle for each output pixel. Only available if orthorectification is enabled.
scatteringAreaThe normalized scattering area for each output pixel. Used for conversion of beta0 to terrain corrected gamma0. Only available if radiometric terrain correction is performed.
shadowMaskFlags output pixels which are in or near radar shadow. Is true if the nearest GRD source pixel is at most one GRD pixel away from a GRD pixel with a scatteringArea of less than 0.05.
dataMaskThe mask of data/nodata pixels (more).


The data values for each band in your custom script are presented in the default units as specified here. In case more than one unit is available for a given band, you may optionally set the value of input.units in your evalscript setup function to one of the options. Doing so will present data in that unit. The Source Format specifies how and with what precision the digital numbers from which the unit is derived are encoded. The Typical Range indicates what values are common for a given band and unit, however outliers can be expected.

For Sentinel-1, data values are linear power in the chosen backscattering coefficient. To specify the backscattering coefficient, set BETA0, SIGMA0_ELLIPSOID, GAMMA0_ELLIPSOID (default) or GAMMA0_TERRAIN as the value of in your request. The default is GAMMA0_ELLIPSOID.

BandUnitSource FormatTypical RangeNotes
Linear power in the chosen backscattering coefficientUINT160 - 0.5Can reach very high values (such as 1000); for visualizing a large dynamic range consider converting to decibels: decibel = 10 * log10 (linear).
localIncidenceAngledegreesN/A0 - 180Computed for each output pixel. Requires that orthorectification is enabled
scatteringAreaunitlessN/A0 - 2Can reach high values on foreslopes
shadowMaskN/Aboolean0 - likely not radar shadow
1 - likely in/near radar shadow
dataMaskN/Aboolean0 - no data
1 - data

Scenes Object

scenes object stores metadata. An example of metadata available in scenes object for Sentinel-1 GRD when mosaicking is ORBIT:

Property nameValue

Properties of a scenes object can differ depending on the selected mosaicking and in which evalscript function the object is accessed. Working with metadata in evalscript user guide explains all details and provide examples.


SIMPLE and ORBIT mosaicking types are supported.

Collection specific constraints

  • Noise: All products on both services have thermal noise reduction applied.
  • Decibel units: For decibel outputs, a conversion is necessary within your evalscript, see an example here. We offer pre-defined evalscripts, which return S1GRD values in decibel units, as products in the Configuration Utility for your convenience.
  • Orbit state vectors: We currently use the orbit state vectors provided in the products themselves as we find these sufficient for GRD use.

Catalog API Capabilities

To access Sentinel-1 GRD product metadata you need to send search request to our Catalog API. The requested metadata will be returned as JSON formatted response to your request. This chapter will help with understanding Sentinel 1 GRD specific parameters for search request.

Endpoint Locations

ServiceNotes since October 2014 policy of 48 months for Europe
Rolling policy of 12 months for World

Collection identifier: sentinel-1-grd

Query extension

Distinct extension

  • date
  • sar:instrument_mode
  • sat:orbit_state
  • polarization


S1 GRD examples