Operations of Landsat 7 in bumper mode were successfully tested over several geometric calibration sites on Mar. 3 and 19. Currently, the motion of Landsat 7’s scan mirror during imaging is controlled with the Scan Angle Monitor (SAM). However, the scan mirror assembly will wear over time and impede the instrument’s ability to synchronize the calibration shutter with the scan mirror. This is predicted to happen between Mar. 2007 and Jan. 2008. When this occurs, operations will be switched to bumper mode. Landsat 5 has been operating in bumper mode since 2002.
Safeguarding freshwater resources is crucial, and while scientists use a variety of ground-based techniques to gauge water quality, the Landsat program has provided water quality data from orbit for decades.