Status of the Landsat thematic mapper and multispectral scanner archive conversion system

The U.S. Geological Survey's EROS Data Center (EDC) manages the National Satellite Land Remote Sensing Data Archive. This archive includes Landsat thematic mapper (TM) multispectral scanner (MSS) data acquired since 1972. The Landsat archive is an important resource to global change research.

To ensure long-term availability of Landsat data from the archive, the EDC specified requirements for a Thematic Mapper and Multispectral Scanner Archive Conversion System (TMACS) that would preserve the data by transcribing it to a more durable medium. In addition to media conversion, hardware and software was installed at EDC in July 1992. In December 1992, the EDC began converting Landsat MSS data from high-density, open reel instrumentation tapes to digital cassette tapes. Almost 320,000 MSS images acquired since 1979 and more than 200,000 TM images acquired since 1982 will be converted to the new medium during the next 3 years.

During the media conversion process, several high-density tapes have exhibited severe binder degradation. Even though these tapes have been stored in environmentally controlled conditions, hydrolysis has occurred, resulting in "sticky oxide shed". Using a thermostatically controlled oven built at EDC, tape "baking" has been 100 percent successful and actually improves the quality of some images.