MODIStsp_process_bands: MODIStsp helper for processing original HDF layers

Description

Internal function used to perform the required spatial processing on MODIS original hdf layers (reprojection, resizing, resampling, mosaicing, computation of scaling factors). The function is based on the use of gdal routines.

Usage

MODIStsp_process_bands(
  out_folder_mod,
  modislist,
  outproj_str,
  mod_proj_str,
  sens_sel,
  band,
  bandname,
  date_name,
  datatype,
  nodata_in,
  nodata_out,
  full_ext,
  bbox,
  scale_val,
  scale_factor,
  offset,
  out_format,
  outrep_file,
  compress,
  out_res_sel,
  out_res,
  resampling,
  nodata_change,
  gui,
  verbose,
  parallel
)

Value

The function is called for its side effects

Arguments

out_folder_mod: character Output folder for original HDF storage. If "$tempdir" (default), a temporary directory is used.
modislist: character array List of MODIS images to be downloaded for the selected date (as returned from get_mod_filenames). Can be a single image, or a list of images in case different tiles are needed!
outproj_str: character EPSG or WKT of output projection.
mod_proj_str: character EPSG or WKT of MODIS projection.
sens_sel: character ["terra" | "aqua"] Selected sensor.
band: numeric band number corresponding to the HDF layer to be processed
bandname: character Name of the HDF layer to be processed.
date_name: character Date of acquisition of the images to be downloaded.
datatype: character Datatype to the HDF layer to be processed.
nodata_in: numeric Original nodata value to the HDF layer to be processed.
nodata_out: numeric Output nodata value to the HDF layer to be processed.
full_ext: logical If TRUE, process full tiles, if FALSE, process bbox
bbox: numeric(4) Output bounding box (xmin, ymin, xmax, ymax) in out_proj coordinate system. Ignored if spatmeth == "tiles", Default: NULL
scale_val: logical If TRUE, scale and offset are applied to original MODIS layers, and Spectral Indexes are saved as floating point. If FALSE, no rescaling is done and Spectral Indexes are saved as integer, with a 10000 scaling factor.
scale_factor: numeric Scale factor to be applied to the HDF layer to be processed (Ignored if scale_val == FALSE).
offset: numeric Offset to be applied to the HDF layer to be processed (Ignored if scale_val == FALSE).
out_format: character ["ENVI" | "GTiff"] Desired output format.
outrep_file: character Full path of the file where results of the processing are to be stored (created in MODIStsp_process)
compress: character ["None" | "PACKBITS" | "LZW" | "DEFLATE"] Compression method for GTiff outputs (Ignored if out_format == ENVI)
out_res_sel: character ["Native", "User Defined]. If "Native", the outputs keep the original resolution of MODIS HDF images. Otherwise, the value set in "out_res" is used.
out_res: float Output resolution (in output projection measurement unit). Ignored if out_res_sel == "Native".
resampling: character ["near" | "bilinear" | "cubic" | "cubicspline", |lanczos"|, "average"|, "mode", |"max"|, |"min"|, |"q1"|, |"q3"|, |"sum"|] Resampling method to be used by gdalwarp.
nodata_change: logical if TRUE, NoData values are set to the max value of the datatype of the layer on the MODIStsp output rasters. NOTE: If multiple nodata values are reported for a layer, all are reset to the new value.
gui: logical if TRUE: the GUI is opened before processing. If FALSE: processing parameters are retrieved from the provided opts_file argument), Default: TRUE
verbose: logical If FALSE, suppress processing messages, Default: TRUE
parallel: logical If TRUE, the function is run using parallel processing, to speed-up the computation for large rasters (with a maximum of 8 cores). The number of cores is automatically determined; specifying it is also possible (e.g. parallel = 4). In this case, more than 8 cores can be specified. If FALSE (default), single core processing is used.

Author

Lorenzo Busetto, phD (2014-2017)

Luigi Ranghetti, phD (2015)