landsat
.read.landsat(file, band="all", emissivity=0.984, debug=getOption("oceDebug"))
metadata@emissivity
in the resultant object. This is used in the
calculation of surface temperature, as explained in the discussion of
accessor functions for
landsat
, with the conventional Oce slots
metadata
, data
and processingLog
. The metadata
is mainly intended for use by Oce functions, but for generality it also
contains an entry named header
that represents the full image header
in a list (with names made lower-case). The data
slot holds
matrices of the data in the requested bands, and users may add extra
matrices if desired, e.g. to store calculated quantities.landsat-class
). In
R, many operations involving copying data, so that dealing with full-scale
landsat images can overwhelm computers with storage under 8GB.
For this reason, it is typical to read just the bands that are of interest.
It is also helpful to use landsatTrim
to trim the data to a
geographical range.tiff
package must be installed for this to work.
Landsat data are provided in directories that contain TIFF files and header
information, and read.landsat
relies on a strict convention for the
names of the files in those directories. Those file names were found by
inspection of some data, on the assumption that similar patterns will hold
for other datasets for any given satellite. This is a brittle approach and
it should be born in mind if read.landsat
fails for a given dataset.
For Landsat 8, there are 11 bands, with names "aerosol"
(band 1),
"blue"
(band 2), "green"
(band 3), "red"
(band 4),
"nir"
(band 5), "swir1"
(band 6), "swir2"
(band 7),
"panchromatic"
(band 8), "cirrus"
(band 9), "tirs1"
(band 10), and "tirs2"
(band 11). For Landsat 7, there 8 bands, with names "blue"
(band 1),
"green"
(band 2), "red"
(band 3), "nir"
(band 4),
"swir1"
(band 5), "tir1"
(band 6A), "tir2"
(band 6B),
"swir2"
(band 7) and "panchromatic"
(band 8).
For Landsat 4 and 5, the bands similar to Landsat 7 but without
"panchromatic"
(band 8).
See landsat-class
for more information on the data storage
scheme, and also on the bands and their processing.
landsat-class
for more information on landsat
objects, especially band information. Use landsatTrim
to
trim Landsat objects geographically and landsatAdd
to add new
``bands.'' The accessor operator ([[
) is used to access band
information, full or decimated, and to access certain derived quantities.
A sample dataset named landsat
is available in the ocedata
package.