What is Landsat 8 OLI/TIRS Pre-WRS-2 data?
The Landsat 8 OLI/TIRS Pre-WRS-2 data set contains nearly 10,000 scenes acquired by the Operational Land Imager (OLI) and/or Thermal Infrared Sensor (TIRS) sensors after launch (February 11, 2013) through April 10, 2013, when the satellite achieved operational orbit (WRS-2). The earliest images are TIRS data only. While these data meet the quality standards and have the same geometric precision as data acquired on April 12, 2013 and beyond, the geographic extents of each scene will differ. The data acquired during the Landsat 7/Landsat 8 underfly on March 29 - 30, 2013 are also available.
This information can also be found on the USGS Landsat 8 website.