Landsat 9 Project Scientist Jeff Masek discusses the ways Landsat data is used and how important it is to have high quality data.
How is the C Function of Mask algorithm used with Landsat Level-1 data?
The C Function of Mask (CFMask) algorithm populates cloud, cloud confidence, cloud shadow, and snow/ice pixels in the processing of Landsat Collections Level-1 data products, with the results represented as bit-mapped values within the Landsat Collection 1 Level-1 Quality Assessment (QA) Band. CFMask derives from the Function of Mask (FMask), an algorithm written in MATLAB at Boston University and translated into the C programming language at USGS EROS to facilitate its implementation in a production environment. The CFMask is also compatible with Collection 2 level-1 data products.
CFMask is a multi-pass algorithm that uses decision trees to prospectively label pixels in the scene; it then validates or discards those labels according to scene-wide statistics. It also creates a cloud shadow mask by iteratively estimating cloud heights and projecting them onto the ground.
While the CFMask algorithm is designed by default to be run with thermal data, it is possible to employ it without a thermal input. This may be necessary at times, such as when thermal data from Landsat 8 Thermal Infrared Sensor (TIRS) is not immediately available.
Currently, non-thermal CFMask is run by removing all thermal threshold tests from the algorithm. Users should be aware that this change does alter the results of the cloud, cloud confidence, cloud shadow, and snow/ice detection routines.
Learn more: CFMask Algorithm
Related Content
Does Landsat Level-1 data processing include atmospheric correction?
Landsat Level-1 data are not corrected for atmospheric conditions; however, Landsat Science Products are atmospherically corrected. Learn more: L andsat Level-1 data Landsat U.S. Analysis Ready Data Landsat Level-2 and Level-3 Science Products Landsat Data Access
How do I rescale Landsat Level-1 digital numbers to reflectance, radiance, and brightness temperature?
Landsat Level-1 data can be rescaled to the top of atmosphere (TOA) reflectance and/or radiance using radiometric rescaling coefficients provided in the metadata file (MTL.txt) that is delivered with the Landsat Level-1 product. The MTL file also contains the thermal constants needed to convert thermal band data to TOA brightness temperature (BT). Formulas for these conversions are at Using the...
I have a list of historical Landsat Level-1 Scene IDs; how can I determine the corresponding Landsat Collections Level-1 Product Identifier?
The historical Landsat Level-1 Scene ID is in the EarthExplorer metadata. After entering a search using the historical Scene ID, the Landsat Level-1 Collection 1 Product Identifier will be returned in the search results. The results can be exported from EarthExplorer in a variety of formats for metadata parsing. We also encourage use of the Bulk Metadata Service to download files that contain both...
What is the naming convention for Landsat Collections Level-1 scenes?
The Landsat Collection 1 Level-1 product identifier includes the Collection processing levels, processing date, collection number, and collection tier category: LXSS_LLLL_PPPRRR_YYYYMMDD_yyyymmdd_CC_TX Where: L = Landsat X = Sensor (“C”=OLI/TIRS combined, “O”=OLI-only, “T”=TIRS-only, “E”=ETM+, “T”=“TM, “M”=MSS) SS = Satellite (”07”=Landsat 7, “08”=Landsat 8) LLL = Processing correction level (L1TP...
What are the processing levels for Landsat Level-1 data?
The table below shows the Landsat Collections Level-1 processing levels: Landsat Level-1 Processing Levels Processing Level Description 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...
What are the Landsat Collection 1 Level-1 data product file sizes?
The file sizes of Landsat Collection 1 Level-1 data products are listed below: Sensor Compressed file Uncompressed file Landsat 8 OLI/TIRS 919 MB 1.61 GB Landsat 7 ETM+ 235 MB 785 MB Landsat 4-5 TM 150 MB 500 MB Landsat 1-5 MSS 20 MB 75 MB
Landsat in Action - The Accuracy of Landsat with Jeff Masek
Landsat 9 Project Scientist Jeff Masek discusses the ways Landsat data is used and how important it is to have high quality data.
Landsat's Calibration and Validation
Engineers and scientists from both Landsat and Sentinel missions are working together to calibrate observation data and validate its quality to improve the science using these resources.
Engineers and scientists from both Landsat and Sentinel missions are working together to calibrate observation data and validate its quality to improve the science using these resources.
Landsat Collections
Landsat Collections: Providing a Stable Environmental Record for Time Series Analysis
Landsat Collections: Providing a Stable Environmental Record for Time Series Analysis
Landsat Collections — What are Tiers?
This is the third video in a series describing the new U.S. Geological Survey (USGS) Landsat Collection 1 inventory structure. Collection 1 required the reprocessing of all archived Landsat data to achieve radiometric and geometric consistency of Level-1 products through time and across all Landsat sensors.
This is the third video in a series describing the new U.S. Geological Survey (USGS) Landsat Collection 1 inventory structure. Collection 1 required the reprocessing of all archived Landsat data to achieve radiometric and geometric consistency of Level-1 products through time and across all Landsat sensors.
Landsat Collections - RMSE
Landsat Collections: Providing a Stable Environment Record for Time Series Analysis
Landsat Collections: Providing a Stable Environment Record for Time Series Analysis
Related Content
- FAQ
Does Landsat Level-1 data processing include atmospheric correction?
Landsat Level-1 data are not corrected for atmospheric conditions; however, Landsat Science Products are atmospherically corrected. Learn more: L andsat Level-1 data Landsat U.S. Analysis Ready Data Landsat Level-2 and Level-3 Science Products Landsat Data Access
How do I rescale Landsat Level-1 digital numbers to reflectance, radiance, and brightness temperature?
Landsat Level-1 data can be rescaled to the top of atmosphere (TOA) reflectance and/or radiance using radiometric rescaling coefficients provided in the metadata file (MTL.txt) that is delivered with the Landsat Level-1 product. The MTL file also contains the thermal constants needed to convert thermal band data to TOA brightness temperature (BT). Formulas for these conversions are at Using the...
I have a list of historical Landsat Level-1 Scene IDs; how can I determine the corresponding Landsat Collections Level-1 Product Identifier?
The historical Landsat Level-1 Scene ID is in the EarthExplorer metadata. After entering a search using the historical Scene ID, the Landsat Level-1 Collection 1 Product Identifier will be returned in the search results. The results can be exported from EarthExplorer in a variety of formats for metadata parsing. We also encourage use of the Bulk Metadata Service to download files that contain both...
What is the naming convention for Landsat Collections Level-1 scenes?
The Landsat Collection 1 Level-1 product identifier includes the Collection processing levels, processing date, collection number, and collection tier category: LXSS_LLLL_PPPRRR_YYYYMMDD_yyyymmdd_CC_TX Where: L = Landsat X = Sensor (“C”=OLI/TIRS combined, “O”=OLI-only, “T”=TIRS-only, “E”=ETM+, “T”=“TM, “M”=MSS) SS = Satellite (”07”=Landsat 7, “08”=Landsat 8) LLL = Processing correction level (L1TP...
What are the processing levels for Landsat Level-1 data?
The table below shows the Landsat Collections Level-1 processing levels: Landsat Level-1 Processing Levels Processing Level Description 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...
What are the Landsat Collection 1 Level-1 data product file sizes?
The file sizes of Landsat Collection 1 Level-1 data products are listed below: Sensor Compressed file Uncompressed file Landsat 8 OLI/TIRS 919 MB 1.61 GB Landsat 7 ETM+ 235 MB 785 MB Landsat 4-5 TM 150 MB 500 MB Landsat 1-5 MSS 20 MB 75 MB
- Multimedia
Landsat in Action - The Accuracy of Landsat with Jeff Masek
Landsat 9 Project Scientist Jeff Masek discusses the ways Landsat data is used and how important it is to have high quality data.
Landsat 9 Project Scientist Jeff Masek discusses the ways Landsat data is used and how important it is to have high quality data.
Landsat's Calibration and ValidationEngineers and scientists from both Landsat and Sentinel missions are working together to calibrate observation data and validate its quality to improve the science using these resources.
Engineers and scientists from both Landsat and Sentinel missions are working together to calibrate observation data and validate its quality to improve the science using these resources.
Landsat CollectionsLandsat Collections: Providing a Stable Environmental Record for Time Series Analysis
Landsat Collections: Providing a Stable Environmental Record for Time Series Analysis
Landsat Collections — What are Tiers?This is the third video in a series describing the new U.S. Geological Survey (USGS) Landsat Collection 1 inventory structure. Collection 1 required the reprocessing of all archived Landsat data to achieve radiometric and geometric consistency of Level-1 products through time and across all Landsat sensors.
This is the third video in a series describing the new U.S. Geological Survey (USGS) Landsat Collection 1 inventory structure. Collection 1 required the reprocessing of all archived Landsat data to achieve radiometric and geometric consistency of Level-1 products through time and across all Landsat sensors.
Landsat Collections - RMSELandsat Collections: Providing a Stable Environment Record for Time Series Analysis
Landsat Collections: Providing a Stable Environment Record for Time Series Analysis
- Publications