MODIStsp_process_indexes: MODIStsp helper for computing spectral indexes

Description

function used to compute spectral indexes, given the index formula

Usage

MODIStsp_process_indexes(
  out_filename,
  out_prod_folder,
  formula,
  bandnames,
  nodata_out,
  indexes_nodata_out,
  file_prefix,
  compress,
  yy,
  out_format,
  DOY,
  scale_val
)

Value

NULL - new raster file saved in out_filename

Arguments

out_filename: character basename of the file in to which save results
out_prod_folder: character output folder for the product used to retrieve filenames of rasters of original bands to be used in computations
formula: character Index formula, as derived from XML file and stored in prod_opts within previous_file
bandnames: character array of names of original HDF layer. Used to identify the bands required for index computation
nodata_out: character array of NoData values of reflectance bands
indexes_nodata_out: character NoData value for resulting raster
file_prefix: character used to retrieve filenames of rasters of original bands to be used in computations
compress: character compression option for GTiff files
yy: character year string used to retrieve filenames of rasters of original bands to be used in computations
out_format: character string used to retrieve filenames of rasters of original bands to be used in computations
DOY: character doy string used to retrieve filenames of rasters of original bands to be used in computations
scale_val: character (Yes/No) if Yes, output values in are computed as float -1 - 1, otherwise integer -10000 - 10000

Author

Lorenzo Busetto, phD (2017)

Luigi Ranghetti, phD (2017)

Details

the function parses the index formula to identify the required bands. On the basis of identified bands, it retrieves the reflectance bands required, gets the data into R raster objects, performs the computation and stores results in a GeoTiff or ENVI raster file