Landsat Collection 2 Quality Assessment Bands

Return to Landsat Collection 2 Information

Landsat Collection 2 Level-1 Quality Assessment Bands

The following quality assessment information is created for all sensors (Landsat 1-9) during Landsat Collection 2 Level 1 product generation: 

• Pixel Quality Assessment band (QA_PIXEL)
• Radiometric Saturation Quality Assessment band (QA_RADSAT)

The QA_PIXEL and QA_RADSAT bands are carried through unchanged and included in the Level 2 Surface Reflectance and Surface Temperature Science Product package.
 

Pixel Quality Assessment Band (QA_PIXEL)

The QA_PIXEL band provides detailed information on conditions that influence the quality of each pixel in a scene. Its unsigned integer values are bit-packed to represent combinations of pixel characteristics and quality indicators. 

The table below displays the bit assignments for the Landsat 8-9 QA_PIXEL band. The most common QA_PIXEL bit values can be viewed in Table 6‑3 of the Landsat 8-9 Collection 2 Level 2 Science Product Guide. 

To view bit assignments for Landsat 1-7 Level-1 products, refer to the documents listed at the bottom of this page. 

Radiometric Saturation Quality Assessment Band (QA_RADSAT)

The QA_RADSAT band indicates which sensor band(s) are saturated. The terrain occlusion bit is set when the desired terrain is not visible from the sensor due to intervening terrain (Landsat 8-9 only) and the dropped pixel bit is set when a pixel is dropped (Landsat 1-7).

Landsat Collection 2 Level-2 Quality Assessment Bands

Landsat 4-9 Collection 2 Level-2 products include the following Quality Assessment bands: 

• The Level-1 QA_PIXEL and QA_RADSAT bands described above are carried through unchanged in the Level-2 product package.
• Surface Reflectance:
  • Aerosol Quality Assessment band (SR_QA_AEROSOL)  - Landsat 8-9 only
  • Cloud Quality Assessment band (SR_CLOUD_QA) - Landsat 4-7 only
• Surface Temperature:
  • Uncertainty band (ST_QA) - Landsat 4-9 only
     

Surface Reflectance Aerosol Quality Assessment Band (SR_QA_AEROSOL) – Landsat 8-9 only

The SR_QA_AEROSOL band is delivered with the Landsat 8-9 Surface Reflectance product to provide low-level detail about the factors that may have influenced the final product result and shows whether the aerosol was a valid retrieval, or if it was interpolated from the surrounding grid points.

Surface Reflectance Cloud Quality Assessment Band (SR_Cloud_QA) – Landsat 4-7 only

The SR_CLOUD_QA band shares some of the data artifacts and land surface classification indications with the QA_PIXEL band. However, the SR_CLOUD_QA band is generated using the Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) algorithm, unlike the QA_PIXEL band, that is created during Level-1 product generation. 

Landsat 4-7 SR_CLOUD_QA pixel values and value interpretations can be viewed in Table 5‑3 and Table 5-4 of the Landsat 4-7 Collection 2 Level 2 Science Product Guide.
 

Surface Temperature Uncertainty Band (ST_QA)

The ST_QA band indicates the uncertainty about the temperatures provided within the ST band, in Kelvin, and is generated using uncertainty values and distance to cloud values. Higher numbers indicate greater uncertainty. This band is not provided when an SR-only product is generated.

Documents

Collection 2 Level-1 Documents

• Landsat 8-9 OLI/TIRS Collection 2 Level 1 Data Format Control Book
• Landsat 7 ETM+ Collection 2 Level 1 Data Format Control Book
• Landsat 4-5 TM Collection 2 Level 1 Data Format Control Book
• Landsat 1-5 MSS Collection 2 Level 1 Data Format Control Book

Collection 2 Level-2 Documents

• Landsat 8-9 OLI/TIRS Collection 2 Level 2 Data Format Control Book
• Landsat 7 ETM+ Collection 2 Level 2 Data Format Control Book
• Landsat 4-5 TM Collection 2 Level 2 Data Format Control Book
• Landsat 8-9 Collection 2 Level 2 Science Product Guide
• Landsat 4-7 Collection 2 Level 2 Science Product Guide