The U.S. Geological Survey (USGS) has reduced 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 are reduced from $600 to $250. Scenes with the gaps filled in using data acquired prior to the anomaly are also being offered at a reduced price of $275, beginning May 10, 2004.
The 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 EROS Data Center 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 other methods of providing better-merged data products and will continue to provide information resulting from this work as it becomes available.