Data Purge Alert


All organizations holding EO space data have the responsibility to asses the relative value of their data holdings and to preserve them for the long term. Occasionally an organization must make the decision to “purge” one or more datasets that could be important to help meet the mission requirements of an agency. A Data Purge action permanently and irrecoverably removes all copies of an EO dataset held in an organization.


The “Data Purge Alert” procedure aims at preventing, or at least minimizing, the loss of EO space data. Organizations intending, for whatever reason, to purge an EO dataset, should apply the procedure (before purging the data) in order to inform other organizations with the goal to trigger a possible transfer of preservation responsibility to another interested entity.


Communication and Coordination

To activate the procedure please contact the WGISS Chair of the purging intention when no interested entity has been directly identified, through the ad-hoc email (see with a description of the case, and using the following subject: <mission> Dataset to be purged 

Data Purge Alert Document

All relevant information are available in the following document:

Data Purge Alert White Paper

Purge Alerts


U.S. Geological Survey intends to dispose of its Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) satellite film that have digital sources. This film was created between 1972 and 1992.

Approximately two million frames from 9-inch and 70-mm film with an approximate volume of 5,180 cubic feet are being offered to any organization willing to pay the shipping costs. Organizations interested in taking over the responsibility of preserving and maintaining the aforementioned Landsat film collection should contact the WGISS Chair ( within three months from the publication of this news. The imagery is considered to be Public Domain so there are no use restrictions.