Landsat Product Price Adjustment - The U.S. Geological Survey (USGS) is reducing the price of Landsat 7 scenes with gaps in data resulting from a satellite anomaly in May of 2003. Scenes that contain gaps in data will be reduced from $600 to $250. A new product being offered for $275 will have the gap areas filled in with Landsat 7 data acquired prior to the scan line corrector (SLC) failure at a similar time of the year. The two scenes are geometrically registered, and a histogram matching technique is applied to the fill pixels that provide the best-expected radiance values for the missing data.

The new product represents an effort by the USGS Landsat 7 Project at the USGS EROS Data Center (EDC) in Sioux Falls, South Dakota, to increase the utility of the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data affected by the non-functional scan line corrector. The USGS is continuing to research methods of providing improved data products and will continue to provide information resulting from this work as it becomes available.

A sample product, with a comparison of the degraded data, further information, a complete list of the new pricing structure, and regular updates on planned product releases can be found at http://landsat.usgs.gov/slc_enhancements/.

Landsat 7 Completes Five Years of Observations - It is worth noting that, on April 15, 2004, Landsat 7 completes five years of operation and will have completed the original planned mission life. In spite of difficulties, Landsats 5 and 7 continue to provide useful observations of a changing planet.

USGS Announces New Product Line - The Landsat Project at the USGS EROS Data Center in Sioux Falls, South Dakota has been taking steps to increase the utility of the ETM+ data that includes non-functional scan line corrector (SLC) artifacts. The SLC on the Landsat 7 ETM+ instrument failed May 31, 2003.

A technique to estimate radiometric values in Landsat 7 data gaps has been selected, and the resulting new products will be available to customers in June 2004. In the planned products, the gap pixels are replaced with data from a previously acquired SLC-on scene that is registered and histogram-matched to the SLC-off
image.

The histogram matching technique is a localized linear transform performed in a moving window throughout the missing pixels. In March 2004, the current ETM+ SLC-off product will be available to the public with a user-selectable amount of interpolation to replace missing gap pixels. The USGS is continuing to research other methods of providing better gap pixel estimates/merged data products and will continue to provide information resulting from this work as it becomes available. A sample product, with a comparison with the degraded data, further information, and regular
updates on the planned product release can be found on our SLC Enhancements page.