Reads Landsat MTL or XML metadata files and loads single Landsat Tiffs into a rasterStack. Be aware that by default stackMeta() does NOT import panchromatic bands nor thermal bands with resolutions != 30m.
Arguments
- file
Character. Path to Landsat MTL metadata (*_MTL.txt) file or an Landsat CDR xml metadata file (*.xml).
- quantity
Character vector. Which quantity should be returned. Options: digital numbers ('dn'), top of atmosphere reflectance ('tre'), at surface reflectance ('sre'), brightness temperature ('bt'), spectral index ('index'), all quantities ('all').
- category
Character vector. Which category of data to return. Options 'image': image data, 'pan': panchromatic image, 'index': multiband indices, 'qa' quality flag bands, 'all': all categories.
- allResolutions
Logical. if
TRUEa list will be returned with length = unique spatial resolutions. This argument was introduced to maintain backward compatibility and will be switched to TRUE in an upcoming release. Please base all new code on terra.
Value
Returns one single SpatRaster comprising all requested bands.
If allResolutions = TRUE *and* there are different resolution layers (e.g. a 15m panchromatic band along wit 30m imagery) a list of RasterStacks will be returned.
Note
Be aware that by default stackMeta() does NOT import panchromatic bands nor thermal bands with resolutions != 30m. Use the allResolutions argument to import all layers. Note that nowadays the USGS uses cubic convolution to resample the TIR bands to 30m resolution.
Examples
## Example metadata file (MTL)
mtlFile <- system.file("external/landsat/LT52240631988227CUB02_MTL.txt", package="RStoolbox")
## Read metadata
metaData <- readMeta(mtlFile)
summary(metaData)
#> Scene: LT52240631988227CUB02
#> Satellite: LANDSAT5
#> Sensor: TM
#> Date: 1988-08-14
#> Path/Row: 224/63
#> Projection: +proj=utm +zone=22 +units=m +datum=WGS84 +ellips=WGS84
#> Scene: PROJCRS["unknown",
#> BASEGEOGCRS["unknown",
#> DATUM["World Geodetic System 1984",
#> ELLIPSOID["WGS 84",6378137,298.257223563,
#> LENGTHUNIT["metre",1]],
#> ID["EPSG",6326]],
#> PRIMEM["Greenwich",0,
#> ANGLEUNIT["degree",0.0174532925199433],
#> ID["EPSG",8901]]],
#> CONVERSION["UTM zone 22N",
#> METHOD["Transverse Mercator",
#> ID["EPSG",9807]],
#> PARAMETER["Latitude of natural origin",0,
#> ANGLEUNIT["degree",0.0174532925199433],
#> ID["EPSG",8801]],
#> PARAMETER["Longitude of natural origin",-51,
#> ANGLEUNIT["degree",0.0174532925199433],
#> ID["EPSG",8802]],
#> PARAMETER["Scale factor at natural origin",0.9996,
#> SCALEUNIT["unity",1],
#> ID["EPSG",8805]],
#> PARAMETER["False easting",500000,
#> LENGTHUNIT["metre",1],
#> ID["EPSG",8806]],
#> PARAMETER["False northing",0,
#> LENGTHUNIT["metre",1],
#> ID["EPSG",8807]],
#> ID["EPSG",16022]],
#> CS[Cartesian,2],
#> AXIS["(E)",east,
#> ORDER[1],
#> LENGTHUNIT["metre",1,
#> ID["EPSG",9001]]],
#> AXIS["(N)",north,
#> ORDER[2],
#> LENGTHUNIT["metre",1,
#> ID["EPSG",9001]]]]
#>
#> Data:
#> FILES QUANTITY CATEGORY
#> B1_dn LT52240631988227CUB02_B1.TIF dn image
#> B2_dn LT52240631988227CUB02_B2.TIF dn image
#> B3_dn LT52240631988227CUB02_B3.TIF dn image
#> B4_dn LT52240631988227CUB02_B4.TIF dn image
#> B5_dn LT52240631988227CUB02_B5.TIF dn image
#> B6_dn LT52240631988227CUB02_B6.TIF dn image
#> B7_dn LT52240631988227CUB02_B7.TIF dn image
#>
#> Available calibration parameters (gain and offset):
#> dn -> radiance (toa)
#> dn -> brightness temperature (toa)
#>
## Load rasters based on metadata file
lsat <- stackMeta(mtlFile)
lsat
#> class : SpatRaster
#> dimensions : 310, 287, 7 (nrow, ncol, nlyr)
#> resolution : 30, 30 (x, y)
#> extent : 619395, 628005, -419505, -410205 (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / UTM zone 22N (EPSG:32622)
#> sources : LT52240631988227CUB02_B1.TIF
#> LT52240631988227CUB02_B2.TIF
#> LT52240631988227CUB02_B3.TIF
#> ... and 4 more source(s)
#> names : B1_dn, B2_dn, B3_dn, B4_dn, B5_dn, B6_dn, ...
#> min values : 54, 18, 11, 4, 2, 131, ...
#> max values : 185, 87, 92, 127, 148, 146, ...