Landsat Collections data are processed to Level-1 using the Landsat Product Generation System (LPGS), which applies standard processing parameters. Level-1 scene-based products are created using the best processing level available for each scene.
The processing level used is determined by the existence of ground control points (GCP), elevation data provided by a Digital Elevation Model (DEM), and/or data collected by the spacecraft and sensor (Payload Correction Data (PCD). See the Landsat Geometry page for a full description of the processing levels used and additional information about GCP and DEM updates.
- GeoTIFF output format
- Cubic Convolution (CC) resampling method
- 30-meter (TM, ETM+) and 60-meter (MSS) pixel size (reflective bands)
- Universal Transverse Mercator (UTM) map projection (Polar Stereographic projection for scenes with a center latitude greater than or equal to -63.0 degrees)
- World Geodetic System (WGS) 84 datum
MAP (North-up) image orientation
|Terrain Precision Correction (L1TP)||Radiometrically calibrated and orthorectified using ground control points (GCPs) and digital elevation model (DEM) data to correct for relief displacement.The highest quality Level-1 products suitable for pixel-level time series analysis. GCPs used for L1TP correction are derived from the Global Land Survey 2000 (GLS2000) data set.|
|Systematic Terrain Correction (L1GT)||Radiometrically calibrated with systematic geometric corrections applied using the spacecraft ephemeris data and DEM data to correct for relief displacement. Note: L1GT are the highest level of radiometric calibration and systematic correction possible for Landsat 7 and Landsat 8 scenes collected over Antarctica. The L1GT product uses the high-resolution Radarsat Antarctic Mapping Project (RAMP) Version 2 as the elevation correction source.|
|Geometric Systematic Correction (L1GS)||Radiometrically calibration with only systematic geometric corrections applied using the spacecraft ephemeris data.|
Elevation Sources and Ground Control Points
The Standard Terrain Correction (L1TP) and Systematic Terrain Correction (L1GT) products incorporate a Digital Elevation Model (DEM) for topographic accuracy. The Standard Terrain Correction (L1TP) products also utilize ground control points for additional geometric accuracy.
- Ground control points used for Standard Terrain Correction (L1TP) correction are derived from the GLS2000 data set. DEM sources include SRTM, NED, CDED, DTED, GTOPO 30, and GIMP.
- Systematic Terrain Correction (L1GT) is the highest level of correction possible for L7 and L8 scenes collected over Antarctica. The Ramp V2 DEM is the elevation correction source.