Landsat Missions

How usable are Collection 1 “Real-Time” scenes?

You are here

Question:

How usable are Collection 1 “Real-Time” scenes?

Answer:

Landsat "Real-Time" (RT) scenes contain valid Image file data and are usable as is. Newly acquired Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI)/Thermal Infrared Sensor (TIRS) data require a period of evaluation and calibration adjustment after acquisition, but are processed immediately based on preliminary calibration coefficients, assigned to the temporary RT Tier, and made available for download. When definitive calibration information becomes available, RT scenes are reprocessed and assigned to the appropriate Tier 1 (T1) or Tier 2 (T2) category. The Landsat Product Identifier correctly reflects the new category. The details about the follow-on processing for both L7 and L8 are described below. After the follow-on processing is complete and the data is available as T1 or T2, the RT data is removed.

  • Landsat 8 TIRS data may not meet specifications for co-registration with OLI. TIRS line-of-sight model parameters are refined based on data acquired during biweekly calibration maneuvers and scenes are updated within a few weeks of acquisition. The geometry of the OLI data and the radiometry of OLI and TIRS will not change.
  • Landsat 7 ETM+ data use predicted ephemeris and initial bumper mode parameters during initial processing. During a short period of instrument trending/characterization (about 1 week), calibration parameter adjustments finalize the geometric correction model, the data are reprocessed.

About

Landsat represents the world's longest continuously acquired collection of space-based moderate-resolution land remote sensing data. Four decades of imagery provides a unique resource for those who work in agriculture, geology, forestry, regional planning, education, mapping, and global change research. Landsat images are also invaluable for emergency response and disaster relief.

 

Contact Us

Landsat Updates

The Landsat Update is an informal communication tool, prepared periodically and distributed electronically to USGS Landsat partners, to provide information about Landsat activities and related topics of interest.

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://landsat.usgs.gov
Page Contact Information: Ask Landsat
Page Last Modified: 11/29/16 03:03 pm
Sitemap