It is also provided as an additional metadata field in EarthExplorer. The Tier designation (T1, T2, RT) is visible at the end of the Landsat Product Identifier, as shown in the examples below. Users interested in Tier 2 scenes can query the RMSE and other properties to determine their application suitability. This includes Systematic Terrain (L1GT) and Systematic (L1GS) processed data. Tier 2 scenes adhere to the same radiometric standard as Tier 1 scenes, but do not meet the Tier 1 geometry specification due to less accurate orbital information (specific to older Landsat sensors), significant cloud cover, insufficient ground control, or other factors. Landsat scenes not meeting Tier 1 criteria during processing are assigned to Tier 2. The georegistration of Tier 1 scenes is consistent and within prescribed image-to-image tolerances of ≦ 12-meter radial root mean square error (RMSE). Tier 1 includes Level-1 Precision and Terrain (L1TP) corrected data that have well-characterized radiometry and are inter-calibrated across the different Landsat instruments. Landsat scenes with the highest available data quality are placed into Tier 1 and are considered suitable for time-series analysis. TIRS line-of-sight model parameters are refined based on data acquired during biweekly calibration maneuvers and scenes are reprocessed within 14 to 16 days of acquisition and placed into either Tier 1 or Tier 2.
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