[Source: USGS Landsat] On January 9, 2014, the USGS executed a delta-velocity (Delta-V) maneuver to pre-position Landsat 7 for a larger delta-inclination (Delta-I) maneuver used to maintain the satellite’s mean local crossing time. NOAA’s space weather forecast predicted high solar activity during this time that would increase the atmospheric drag on the spacecraft, and therefore, the maneuver’s “burn time” was extended. The geomagnetic storm that was forecast never occurred and caused the delta-v maneuver to perform a slight over-correction and therefore a larger than expected shift in the ground track of the orbit.
A Delta-I was successfully executed on February 4, 2014 that corrected the shift. There are no impacts to Level-1 data processing and product quality is not affected although users may notice a slight difference in the nominal WRS footprint that is more noticeable toward the equator.
Please contact USGS Landsat Customer Services with any questions or concerns: custserv@usgs.gov.