Welcome to the Lofar Long Term Archive (LTA) web service

This service is the main access point for searching and downloading data from the LOFAR LTA. Please visit the documentation for a description on how to use this service. If you have any question please contact the ASTRON SDCO staff via the helpdesk

From March 1 2015 onwards, cycle data which have passed the proprietary period will be publicly available. All metadata in the Archive can be queried anonymously at anytime, but downloading public data can only be done by registered users (follow the "Create account" link). Non-public data can only be downloaded by project members.


  • For the first cycles of LOFAR operations, part of the data were ingested in the archive without metadata. Theses data cannot be found using the standard search parameters, except for the appropriate Observation ID. When unspecified data are present in a project, this is listed in the "Unspecified" column on the Projects page. Data can still be requested using the "Project" pulldown in the various Search options.
  • Since August 2017, after each LOFAR observation, inspection plots are routinely generated, including station dynamic spectra. These plots are used by ASTRON SDCO staff to check the quality of the raw data. They only remain online for 3 weeks from the date of observation. After that, they are compressed and transferred to offline storage. If you wish to access the inspection plots before downloading an observation or pipeline, please contact SDCO staff via the ASTRON helpdesk, and provide the project code and SAS ID of the observation you are interested in. Since June 2019 (the beginning of Cycle 12), the data quality report written by SDCO staff based on the inspection plots can also be made available upon request.

A list of all LOFAR observing cycles and approved projects can be found here.

For more information on this web service see the Lofar wiki.

This system was developed as part of the Target project. Target was supported by Samenwerkingsverband Noord-Nederland (SNN) and the Groningen Municipality. The project was financially supported by the European Fund for Regional Development and the Dutch Ministry of Economic Affairs, Agriculture and Innovation (Pieken in de Delta), the Province of Groningen and the Province of Drenthe.