Calibration and validation are important aspects of any remote sensing system. The calibration of the Landsat sensors is supported by preflight, post launch-onboard, and ground reference data.
Calibration Parameter Files (CPF) provide radiometric and geometric coefficients needed for processing of raw, uncorrected Landsat image data. Each timeframe specific CPF contains calibration coefficients that have been adjusted to correct for the time varying performance of the sensor.
Historical L5 TM and L7 ETM+ CPF Change Logs - details of files affected by CPF updates
The bumper mode calibration files below provide only the coefficients used for geometric processing of raw, uncorrected L5 TM bumper mode data. These coefficients are used to correct misalignments between the forward and reverse scans caused by the L5 TM switch to bumper mode operations on March 1, 2002. The same bumper mode calibration data are also provided in the L5 TM CPF above, but the single values contained in this file format will cover a wider monthly time interval (i.e., coarser trend) and may therefore be less accurate for a given date. In contrast, the L5 TM CPF above will contain an array of daily trend values for the bumper mode calibration parameters.
The Radiometric Lookup Table (LUT) file below provides the latest radiometric gain coefficients currently being used by U.S. Geological Survey (USGS) systems for processing of the L5 TM data. These same radiometric calibration values are also provided within the L5 TM CPF, along with many other radiometric and geometric processing coefficients.
Calibration Notices describe any changes made to the calibration that affects Landsat data products.
Landsat 8 (L8) Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS)
Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+)
Landsat 4-5 Thematic Mapper (TM)
Landsat 1-5 Multispectral Scanner (MSS)
Bias Parameter Files (BPF) supply radiometric correction parameters during Level-1 processing of Landsat 8 data products.
RSS feed for latest Landsat 8 BPFs
Response Linearization Look Up Tables are optional additional files that accompany Calibration Parameter Files (CPF) and contain a mapping look up table to linearize the output of the OLI detectors. This is done to increase the range of Digital Number (DN) values for preciseness and limit the number of saturated pixels to true saturations, and on the dark end, limit it to missing data. Non-linearity characterization uses a series of variable integration time observations of the solar diffuser and corresponding shutter observations to generate a remapping for every digital number (4096 values per detector) for every detector.
Definitive Ephemeris is used to geometrically correct Landsat 4-5 Thematic Mapper and Landsat 7 data. An ephemeris is a set of data that provides the assigned places of a celestial body (including a manmade satellite) for regular intervals. In Landsat 7, definitive ephemeris shows the position and velocity of the satellite in one-minute intervals. More information on definitive ephemeris can be found in the Landsat 7 Data Users Handbook.