Description Usage Arguments Details Value See Also
This function preprocesses surface reflectance imagery from the Landsat
Climate Data Record (CDR) archive. auto_preprocess_landsat
can
reproject CDR tiles to match the projection of a given aoi
, crop the
tiles to match the aoi
or a common WRS-2 path/row polygon, mask
missing data and clouds out of the CDR tiles, and perform topographic
correction.
1 2 3 4 |
image_dirs |
list of paths to a set of Landsat CDR image files as
downloaded from ESPA and extracted by |
prefix |
string to use as a prefix for all filenames |
tc |
whether to topographically correct imagery (if |
dem_path |
path to a set of DEMs as output by |
aoi |
area of interest (AOI), as a |
output_path |
the path to use for the output (optional - if NULL then output images will be saved alongside the input images in the same folder). |
mask_type |
which cloud mask to use to mask clouds when performing
topographic correction. Can be one of "fmask", "6S", or "both". See
Details. (Ignored if |
mask_output |
if |
n_cpus |
the number of CPUs to use for processes that can run in parallel |
cleartmp |
whether to clear temp files on each run through the loop |
overwrite |
whether to overwrite existing files (otherwise an error will be raised) |
of |
output format to use when saving output rasters. See description
of |
ext |
file extension to use when saving output rasters (determines
output file format). Should match file extension for output format chosen by
|
notify |
notifier to use (defaults to |
verbose |
whether to print detailed status messages and timing information |
mask_type
chooses the cloud mask to use if topographic correction is
performed (tc=TRUE
). The mask can be one of three different options:
"6S", "fmask", or "combined". Each option uses a different combination of
cloud mask layers from the CDR product. The "6S" masks out any areas coded
as fill (fill_QA=255), cloud (cloud_QA=255), cloud shadow
(cloud_shadow_QA=255) or adjacent to cloud (adjacent_cloud_QA=255). The
"fmask" option masks out any areas coded as fill (fmask=255), cloud
(fmask=4) or cloud shadow (fmask=2). The combined option combines the "6S"
and "fmask" approaches to masks out areas coded as fill, cloud, cloud
shadow, or adjacent to cloud using either method. Note that "fmask" is the
only supported option when file_format
is L1T. Further, if L1T imagery
is used, fmask must be run locally (see https://code.google.com/p/fmask)
prior to using auto_preprocess_landsat
.
Prior to running auto_preprocess_landsat
, espa_extract
should be used to extract the original zipfiles supplied by USGS. To perform
topographic correction with auto_preprocess_landsat
, first run
auto_setup_dem
to preprocess a set of DEM tiles. Then run
auto_preprocess_landsat
with the tc=TRUE
option.
This function will run in parallel if a parallel backend is registered with
foreach
.
nothing - used for the side effect of preprocessing imagery
espa_extract
, unstack_ledapscdr
,
auto_setup_dem
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