On February 11, 2013, NASA will launch the Landsat Data Continuity Mission (LDCM) into orbit. Once launched and operational, it will be referred to as Landsat 8, joining Landsat 5 and 7 in orbit. The successful launch of LDCM will ensure that over 40 years of Landsat data collection continues to go uninterrupted. The Landsat mission is integral to our understanding of the Earth and how it has changed over time and continues to change.
The LDCM is a joint mission between NASA and the U. S. Geological Survey (USGS) as the USGS will take over operation of the satellite once it is in orbit. The USGS has a long history of making Landsat data freely available to the public for use in scientific research and environmental studies. With its polar orbit and 16-day revisit time, Landsat 8 will allow for consistent data collection of the Earth’s surface.
Onboard Landsat 8 is the Operational Land Imager (OLI), like Landsat satellites before it, the imager will have a 15-meter resolution panchromatic band along with 30-meter resolution multi-spectral bands. The OLI aboard Landsat 8 differs in that it uses a push-broom design for spectral data collection. With over 7,000 detectors for each spectral band positioned across the focal plane, it collects data for the entire swath as the satellite orbits over head. Previously, a whisk broom approach was used, where scan mirrors would sweep across the swath and transmit data to the detectors. This new approach reduces the number of moving parts on the instrument, hopefully increasing its lifespan; and should increase spectral performance by reducing the signal-to-noise ratio.
Another improvement to Landsat 8 is the addition of another thermal spectral band. This decision was made after discovering state water resource managers use Landsat thermal data to inventory land and water resources. Collecting thermal data using two different bands will increase fidelity by helping to distinguish the temperature of the Earth from that of the surrounding atmosphere. Landsat 8 will not only continue a long history of Earth observation with the help of more advanced technology, it will further our understanding of the planet and its precious resources.
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