About the ASF DAAC
The National Aeronautics and Space Administration (NASA) Earth Science Data and Information System (ESDIS) Project is a part of the Earth Science Projects Division under the Flight Projects Directorate at Goddard Space Flight Center. As key components of ESDIS, 12 interlinked Distributed Active Archive Centers (DAAC) are operated by a distributed network of independent facilities across the United States — including the NASA DAAC operated by the Alaska Satellite Facility (ASF).
The ASF DAAC specializes in synthetic aperture radar (SAR) data collection, processing, archiving, and distribution. These data are or have been, supplied by SAR sensors on many different spaceborne and airborne platforms, including:
- European Space Agency’s Sentinel-1, European Remote Sensing Satellite (ERS)-1, and ERS-2
- Japan Aerospace Exploration Agency’s Japanese Earth Resources Satellite (JERS-1) and Advanced Land Observing Satellite (ALOS)
- Canadian Space Agency’s RADARSAT-1 Satellite
- NASA’s SMAP, Airborne Synthetic Aperture Radar (AIRSAR), Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), and Seasat missions.
About ASF DAAC Data
The ASF DAAC has a large archive of synthetic aperture radar (SAR) data from a variety of sensors, available at no cost. Some of the SAR datasets in the ASF DAAC archive require a short NASA proposal for access. In accordance with the memoranda of understanding (MOU) between the relevant flight agencies (CSA, ESA, JAXA) and the U.S. State Department, the ASF DAAC does not distribute SAR data for commercial use.
Sentinel-1, ALOS PALSAR and other SAR data are open access and immediately downloadable from ASF’s Vertex interface, or from the ASF website. ERS-1, ERS-2, JERS-1 and RADARSAT-1 datasets have been acquired in partnership with other nations’ space programs. Those datasets require data proposals or preconditions. In addition, some datasets have residency requirements.
Get SAR Data
Vertex: ASF’s Data Portal
ASF has developed and deployed a user interface to highlight the contents of the pre-processed ASF DAAC SAR datapool. Vertex is an intuitive user interface that facilitates the search for and visualization of ASF DAAC datapool assets, delivery of relevant metadata about those assets, and bulk delivery of those ASF data. Vertex is designed to familiarize users with SAR data without requiring any prior knowledge of SAR platforms, beam modes, or processing parameters.
ASF’s API is an application programming interface that enables command-line search and download.
ASF has configured a MapServer to better serve GIS-savvy clientele. MapServer is an open source platform for publishing spatial data and interactive mapping applications to the web as a Web mapping service. The primary benefit of this server for the ASF user community is the ability to connect directly to ASF’s archived mosaics from personal GIS environments, specifically from the QGIS or ArcGIS application suites.
ASF Simple Subset Agent (SSA)
Through collaborative efforts of the NASA DAACs, a new Simple Subset Wizard (SSW) has been developed for the seamless data retrieval of unrestricted products from all DAACs through one simple user interface. The SSW has minimal required search parameters such as latitude and longitude coordinates, date range of interest, and keywords, to access data archived at multiple DAACs simultaneously, including the ASF DAAC. The ASF Simple Subset Agent (SSA) works synchronously with the SSW spatial and temporal search criteria, to explore the UAVSAR and AIRSAR datasets of the unrestricted SAR datapool at ASF. Searches provide links to browse imagery of the SAR data users are interested in over the area defined in the SSW.
The entirety of the UAVSAR and AIRSAR collections archived at ASF can be accessed for direct download at Vertex.