Landsat Collections: Providing a Stable Environmental Record for Time Series Analysis
This video introduces the new U.S. Geological Survey (USGS) Landsat Collection 1 inventory structure. Collection 1 required the reprocessing of all archived Landsat data to achieve radiometric and geometric consistency of Level-1 products through time and across all Landsat sensors. This video explains why Collection 1 is the highest quality inventory of Landsat Level-1 products ever created. To learn more about Landsat Collections please visit https://landsat.usgs.gov/landsat-collections.
The Landsat Program is a series of Earth-observing satellites co-managed by USGS and NASA, and offers the longest continuous space-based record of Earth’s land in existence. Every day, Landsat satellites orbit Earth and provide essential information to help land managers and policymakers make informed decisions about our natural resources and environment. All Landsat data are distributed by the USGS at no charge from EarthExplorer, GloVis NEXT and the LandsatLook Viewer. To learn more about the Landsat Program please visit https://landsat.usgs.gov/ or follow us on Twitter @USGSLandsat or Facebook @NASA.Landsat.
Location Taken: Sioux Falls, SD, US
Video Credits: Content created by Andy Dykstra and Linda Owen (Contractors to USGS EROS)
[Brian Sauer] What we did in the past was, we’d process the data based on the most current calibration parameters, or the best updates at the time.
Our customers had to go through a lot of work to determine where the data actually came from and what system was actually used to process it.
We had been working a set of product improvements with the science team, and trying to understand science team needs and use cases. So, we were trying to understand, really, how they would use the data and how customers are using the data, and then how we can further enable that data for analysis. [Narrator]
Landsat “Collections” is the result of a better understanding of how Landsat scenes are used. “Collections” goal is to calibrate Landsat scenes and determine the quality of each pixel, providing more useable data. [Brian] There’s really three main buckets that the data gets put into.
So, when we get the data off the satellite, what we do is we process the data and make it available as quickly as possible and put it in what we call a “near real time” bucket.
After the near-real time data is processed, and based on the quality of the geometry, we either put it in Tier 1 or Tier 2.
So, when they’re using it in science applications, one of our objectives was to get the data so it was processed in a consistent manner radiometrically, and geometrically, so users could determine the prominence of the data just by looking at the filename, so it lets the user easily be able to go through the archive and pick high quality data that really stacks over time. [Narrator]
The entire Landsat archive, back from Landsat 4 to Landsat 8 and beyond is available through “Collections” precisely and consistently calibrated, and categorized, which provides the highest quality Landsat data. [Brian]
The key pieces in “Collections” helps us to get towards modernizing our Landsat archive. And that modernization effort is really enabling scientists and users to take advantage of this full record of Landsat that’s so valuable to the community.