Since the start of the Terra mission, ASTER data have been transferred via tape shipments to collaborators in Japan for processing to Level 1, and then to LP DAAC for archiving and processing to Level 2. Improvements since the initial ground systems were designed now enable efficient electronic transfer of data over the entire path, and in May 2005 electronic transfers became the routine approach for exchanging ASTER data between the several participating international sites.
Consequently, ASTER data now become available at LP DAAC in about one-third of the time required previously - now only approximately one week after acquisition. The average latency when data were transferred by tapes was approximately three and one-half weeks. All locations will retain the capability for tape shipments, but tapes will only be employed if there are interruptions in the standard electronic flow.