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Encode QA Conditions to Integers

Source: R/encodeQA.R
encodeQA.Rd

Intended for use with Landsat 16-bit QA bands. Converts pixel quality flags from human readable to integer, which can then be used to subset a QA image. Please be aware of the default settings which differ for different parameters. Depending on, which sensor and legacy is selected, some quality parameters are not used, since the sequences of available bitwise quality designations differ per sensor and collection.

Usage

encodeQA(
  fill = "no",
  terrainOcclusion = "no",
  radSaturation = "na",
  cloudMask = "all",
  cloud = "all",
  cloudShadow = "all",
  snow = "all",
  cirrus = "all",
  droppedPixel = "no",
  water = "all",
  droppedFrame = "no",
  sensor = "OLI",
  legacy = "collection1"
)

Arguments

fill

Designated fill. Options: c("yes", "no", "all").

terrainOcclusion

Terrain induced occlusion. Options: c("yes", "no", "all").

radSaturation

Number of bands that contain radiometric saturation. Options: c("na", "low", "med", "high", "all") for no bands, 1-2 bands, 3-4 bands, 5 or more bands contain saturation.

cloudMask

Cloud mask. Options: c("yes", "no", "all").

cloud

Cloud confidence. Options: c("na", "low", "med", "high", "all").

cloudShadow

Cloud shadow confidence. Options: c("yes", "no", "all").

snow

Snow / ice confidence. Options: c("na", "low", "med", "high", "all").

cirrus

Cirrus confidence. Options: c("na", "low", "med", "high", "all").

droppedPixel

Dropped pixel. Options: c("yes", "no", "all").

water

Water confidence. Options: c("na", "low", "med", "high", "all").

droppedFrame

Dropped frame. Options: c("yes", "no", "all").

sensor

Sensor to encode. Options: c("OLI", "TIRS", "ETM+", "TM", "MSS").

legacy

Encoding systematic Options: c("collection1", "pre_collection"). Default is "collection1" for the Landsat Collection 1 8-bit quality designations. Use "pre_collection" for imagery downloaded before the Collection 1 quality designations were introduced

Value

Returns the Integer value for the QA values

Note

Only currently populated bits are available as arguments.

References

https://www.usgs.gov/landsat-missions/landsat-collection-1-level-1-quality-assessment-band for Collection 1 quality designations (legacy = "collection1")

Examples

encodeQA(snow = "low", cirrus = c("med", "high"), cloud = "high")
#> [1] 23136 23264 23392 23520 23152 23280 23408 23536