Landsat Quality Assessment ArcGIS Toolbox
Landsat Quality Assessment (QA) bands provide helpful information for evaluating the overall usefulness of individual pixels. Each pixel in the QA band contains an integer value that represents bit-packed combinations of surface, atmospheric, and sensor conditions that can affect pixel quality. QA bands are delivered with Landsat Level-1 data products, Level-2 and Level-3 Science Products, and U.S
Return to Landsat Quality Assessment Tools Overview
This ArcGIS-based toolbox provides functionality to classify and/or extract bit packed values for the QA bands provided with the Landsat Collection 1 (C1) and Collection 2 (C2) Level-1, Level-2, and Level-3 science products. The Landsat Quality Assessment (QA) Tools provide the functionality of extracting bit packed values to individual bands for the Landsat Level-1 BQA band only.
The Landsat QA ArcGIS Toolbox contains functionality to classify and extract bit-packed values from QA bands, which facilitates interpretation, mapping, and applying QA values to the Landsat data products. This toolbox is compatible with both ArcGIS Pro and ArcGIS Desktop (ArcMap). Please note that the ArcMap support is no longer maintained given that ESRI discontinued development of the ArcGIS Desktop.
Download Landsat QA ArcGIS Toolbox Here
Compatible Products
The Landsat QA ArcGIS Pro Toolbox supports all Landsat Level-1, Level-2, and Level-3 bit-packed QA bands. Below table lists supported bit-packed QA bands and description:
| Collection 1 Band | Collection 2 Band | Description | Source | Product Page | Tool Support |
|---|---|---|---|---|---|
| BQA, pixel_qa |
QA_PIXEL | Provides information about the quality of surface, atmospheric, and sensor conditions that can affect the overall usefulness of a given pixel. Populated from C1/C2 Level-1 BQA. Provides information about cloud confidence, cloud shadow, and snow/ice. | Landsat 1-9 Level-1, Landsat 4-9 Level-2 and U.S. ARD (CFMask) | Decode QA and Extract QA Bands | |
| radsat_qa |
QA_RADSAT | This band is a bit-packed representation of which sensor bands were saturated during data capture, yielding unusable data. | Landsat 1-9 Level-1, Landsat 4-9 Level-2 and U.S. ARD TOA |
||
| sr_cloud_qa | SR_CLOUD_QA | Provides per-pixel information about dense dark vegetation, cloud, cloud shadow, adjacency to cloud, snow, and water. | Landsat 4-7 Level-2 and U.S. ARD (LEDAPS) | Surface Reflectance | |
| sr_aerosol | SR_QA_AEROSOL | Provides low-level details about about aerosol factors that may influence the final product. | Landsat 8-9 Level-2 and U.S. ARD (LaSRC) | ||
| l2_flags | L2_FLAGS | Provides per-pixel information about success or failure of processing and validity of sun glint, view angle, solar angle, polarization, chlorophyll-a, etc. | Landsat 8-9 Provisional AR (SeaDAS) | Collection 2 Level-2 Provisional Aquatic Reflectance | |
| N/A | MASK | Indicates where cloud, cloud shadow, and/or snow are true, where the Otsu threshold indicated shade, or where the land cover map specifies that the location is not water. | Landsat 4-9 Level-3 Dynamic Surface Water Extent (DSWE) | Collection 2 Level-3 Dynamic Surface Water Extent |
BQA = Quality Assessment Band, CFMask = C Function of Mask, LaSRC = Landsat Surface Reflectance Code, LEDAPS = Landsat Ecosystem Disturbance Adaptive Processing System, SI = Spectral Indices, SR = Surface Reflectance, TOA = Top of Atmosphere Reflectance, AR = Aquatic Reflectance, SeaDAS = Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Data Analysis System, DSWE = Dynamic Surface Water Extent
Download Landsat QA ArcGIS Toolbox
The Landsat QA ArcGIS Toolbox provides functionality to classify and/or extract bit packed values for all Collection 1 and Collection 2 Level-1, Level-2, and Level-3 science product QA bands. The use of this tool enhances the applications of interpretation, mapping and applying QA values to all Landsat data products.
The Landsat QA ArcGIS Toolbox includes the following tools:
- Decode QA – decodes bit-packed quality information from Landsat Collection 1 and Collection 2 Level-1, Level-2 and Level-3 QA bands. Unlike bit-unpacking tools, Decode does not generate new bands, but instead builds an attribute table from the input and populates each unique value with its respective classification.
- Extract QA Bands – finds all unique values in the QA band, and extracts classes individually, as defined by user input. The tool then writes each class to a new image file, and provides the option to combine all selected classes into a single file.
The Landsat QA ArcGIS Toolbox README file contains installation instructions for the toolbox and all pertinent details for each tool.
Toolbox Caveats
- The ArcGIS Pro Toolbox was developed using ArcGIS Pro version 3.0.1 and Python version 3.9.11. The ArcGIS Desktop (ArcMap) toolbox was designed using ArcMap version 10.8.2 and Python version Python 2.7.18.4. The functionality of the toolbox cannot be guaranteed for previous software versions, and cross-compatibility of newer and future ArcGIS Pro and Python releases are subject to vendor discretion.
- Input data must be in GeoTIFF (.tif), binary (.img), or other single-band raster format supported by ArcGIS.
- Input data must be stored in integer format; any float, double, or complex data types are not supported.
- Any band with values outside of the supported range will not process. If you encounter this issue and believe it to be an error inherent to the tool, please contact USGS User Services.
- If using non-standard (i.e., modified) file naming conventions, the tool may not correctly identify your band type, which may result in incorrect output products. Ensure the collection, sensor and band categories are set accordingly.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.