Landsat 8 was built to do something none of its predecessors had done before: look at the Moon. You may ask why an Earth-observing mission would want to image Earth’s natural orbiting celestial body. Well, it all goes back to getting good data of Earth.
On Feb. 11, 2013, Landsat 8 launched into Earth orbit, riding on an Atlas V rocket. Weighing in at 6,133 pounds, Landsat 8 is the eigth satellite in the long-running Landsat program, jointly managed by NASA and the U.S. Geological Survey.
Landsat satellites circle the globe every 99 minutes, collecting data about the land surfaces passing underneath. After 16 days, the Landsat satellite has passed over every spot on the globe, and recorded data in 11 different wavelength regions. The individual wavelength bands can be combined into color images, with different combinations of the 11 bands revealing different information about the condition of the land cover.
As a Landsat satellite flies over the surface of the Earth the instruments aboard the satellite are able to view a swath 185 kilometers wide and collect images along that swath as the satellite proceeds through its orbit. The spacecraft travels at approximately 4.7 miles per second. The satellite travels from north to south while it’s over the sunlit portion of the Earth, and travels south to north over the dark side of the Earth. One orbit takes about 99 minutes, so that’s about approximately 15 orbits in a 24 hour period.
It’s hard to believe a year has passed since the launch of Landsat 8. This first anniversary is going to be an exciting, upbeat celebration because the new satellite is meeting, if not exceeding, all expectations. “Landsat 8 is nearly perfect,” said Jim Lacasse, Landsat Operations and Maintenance Project Manager. “We’re getting really high quality data.”
Eight months ago, on June 5, 2013, the U.S. Geological Survey decommissioned the venerable Landsat 5 satellite. That day, the USGS Landsat Flight Operations Team transmitted the last command to Landsat 5, effectively terminating the mission and leaving it in a disposal orbit.
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.
The U.S. Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS) updated its online geospatial exploring tool, CropScape, adding Cropland Data Layers from crop year 2013. This tool gives public an easy access to interactive visualization, geospatial queries and dissemination without the need to download specialized software.
Landsat 8 is acquiring around 550 images per day – significantly more than the 400-image-per-day design requirement. Between Landsat 7 (launched in 1999 and still active) and Landsat 8, nearly 1,000 images per day are being collected. This is almost double the imagery collected three years ago, when Landsat 5 and 7 were operating together. The ability of Landsat 8 to image more frequently in persistently cloudy areas (e.g., humid tropics, high latitudes) is improving data collection in areas of critical importance for climate studies.
A flawless launch, followed by the transfer of operational control on May 30 to the U.S. Geological Survey, marked the start of the satellite’s mission to extend an unparalleled record of observing Earth’s landscape from space. Landsat 8 is the latest in the Landsat series of remote-sensing satellites that have provided a continuous record of change across Earth’s land surfaces since 1972.
One year ago today, Landsat 8 blasted off from California’s Vandenberg Air Force Base and arched over the shimmering Pacific on its way into orbit. Landsat 8’s main sensor, the Operational Land Imager (OLI), is the latest model in the long line of Landsat Earth-looking radiometers—sensors that have been measuring visible and infrared light reflected from our planet since 1972.
Landsat Surface Reflectance Climate Data Records (CDRs) are high level Landsat data products that support land surface change studies. Climate Data Records, as defined by the National Research Council, are a time series of measurements with sufficient length, consistency, and continuity to identify climate variability and change. The U.S. Geological Survey (USGS) is using the valuable 40-year Landsat archive to create CDRs that can be used to document changes to Earth’s terrestrial environment.
The series of battles that unfolds with these seven maps is considered one of the most important campaigns in naval history; a campaign that ended with the defeat of the powerful Spanish Armada in 1588. Cartographer Robert Adams created these maps for a 1590 book chronicling the famed naval campaign.
It takes a lot of land to grow food for the world’s seven billion people. About a third of Earth’s terrestrial surface is used for agriculture. And about a third of that, in turn, is used to grow crops. Now, a new NASA-funded effort aims to map crop fields worldwide, identify what’s growing where, and determine whether it’s irrigated or fed by rain.
No Landsat 7 data will be acquired beginning at 8:30 a.m. CT on Tuesday, February 4, 2014, until about 2:15 p.m CT on Wednesday, February 5, 2014 due to a Delta-I (Inclination) maneuver.
The entire Landsat 8 archive will be cleared from the online cache and reprocessed to take advantage of calibration improvements identified during its first year of operation starting on Feb. 3, 2014. All Landsat 8 scenes will be removed from the online cache at this time and these data will be reprocessed starting with the most recent acquisitions and proceeding back to the beginning of the mission. Data will then become available for download. Scenes waiting to be reprocessed will also be available for on-demand product orders. Reprocessing is expected to take approximately 50 days.
