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.
The USGS Landsat 7 Project at the 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.
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.
Also, 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 at http://landsat7.usgs.gov/slc_enhancements/.
