Alaska Satellite Facility - Distributed Active Archive Center

Sentinel-1 – Data and Imagery

Availability of Sentinel-1 Data

Alaska Satellite Facility (ASF) DAAC

ASF maintains a complete archive of processed Sentinel-1 data, available within three days of acquisition. Registration is required, and terms and conditions apply. 

European Space Agency (ESA)

Sentinel-1 data are available from ESA from a Rolling Archive that delivers data within 24 hours of acquisition and maintains recent months of data. Registration is required, and terms and conditions apply.

How to Download Sentinel-1 Data from ASF: Vertex (preferred), API, or Earthdata


Vertex is the Alaska Satellite Facility’s data portal for remotely sensed imagery of Earth. The ASF Datapool offers SAR data products for immediate download.

ASF API Download Tool

The ASF Application Programming Interface (API) Download Tool facilitates the search for, visualization, and bulk delivery of ASF SAR images and metadata.


Users may discover and access Sentinel-1 data held at ASF through the NASA Earthdata Search tool.

Search results for Sentinel granules are bundled, so regardless of the processing level of the original search granule (RAW, SLC, GRD or OCN), all other related granules are shown as well. The search result list for any selected granule includes the ground range detected (GRD) product, because the associated GRD browse image, when available, provides the user with the most accurate information about the data coverage.

Sentinel-1 SAR Modes

Sentinel-1A and Sentinel-1B satellites carry C-band SAR instruments to provide an all-weather, day-and-night supply of imagery of Earth’s entire surface every 6 days.

Extra Wide Swath (EW) Interferometric Wide Swath (IW) Stripmap (SM) Wave (WV)
Acquired with TOPSAR using 5 sub-swaths instead of 3, resulting in lower resolution (20m-x-40m). Intended for maritime, ice, and polar-zone services requiring wide coverage and short revisit times. Acquired with TOPSAR. Default mode over land; 250km swath width; 5m-x-20m ground resolution. Used in rare circumstances to support emergency-management services, 5m-x-5m resolution over an 80km swath width. Default mode over oceans; VV polarization. Data acquired in 20km-x-20km vignettes, 5m-x-20m resolution, every 100km along the orbit.

Naming Convention

The figure below illustrates the Sentinel-1 granule naming convention. For more information, see the Sentinel-1 Technical Guide. Additional resources are listed in Documents and Tools.

sentinel-1 synthetic-aperture radar sar naming-convention diagram showing the numbe r string with each component of the data

Orbit Files and Auxilliary Data Files


  • The Precise Orbit Determination (POD) service for Sentinel-1 provides orbit ephemerides files in the form of Precise Orbit Ephemerides files (available 20 days after data acquisition), Restituted Orbit files (available a few hours after data acquisition). Flight Operation Segment (FOS) Predicted Orbit files (available seven days prior to data acquisition), and Instrument Processing Facility (IPF) auxiliary files L1 Processor Parameters, L2 Processor Parameters, Instrument, Calibration, and Simulated Cross Spectra Auxiliary Data are also available.
  • Users of these vectors may want to refer to the Sentinels POD Service File Format Specifications available on the Documents and Tools page. 

Sentinel-1 Orbit Files at ASF

Sentinel-1 Orbit Files at ESA

ESA Sentinel-1 Quality Control page

Guide to File Names

IPF Auxiliary Data Files
L1 Processor Parameters aux_pp1
Calibration Auxiliary Data aux_cal
Instrument Auxiliary Data aux_ins
L2 Processor Parameters aux_pp2
Simulated Cross Spectra Auxiliary Data aux_scs
Orbit Files
FOS Predicted Orbit mpl_orbpre
POD Precise Orbit Ephemerides aux_poeorb
POD Restituted Orbit aux_resorb
POD Restitude Attitude aux_resatt

Content on ASF’s Sentinel web pages is adapted from the European Space Agency (ESA) Sentinel website.