Why are there lines across my Landsat TM image?
Memory Effect (ME) is an artifact that can be observed as alternating lighter and darker scans. At various times, ME has been known as "banding" or "bright target recovery". ME is typically seen in imagery from bands 1-4, over large areas following a significant transition in radiant intensity such as at a cloud/desert or snow/water boundary.
As of May 11, 2006, all Landsat TM products processed through Level 1 processing will have the Memory Effect (ME) correction algorithm applied at no additional cost. This should significantly reduce or eliminate completely the ME artifacts in the TM image.