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Spatial emissivity correction

tuav_emis.Rd

tuav_emis() corrects a stitched thermal orthomosaic for emissivity, based on a high resolution landcover or emissivity map.

Usage

tuav_emis(
  thermal_orig,
  thermal_uav,
  temp = "K",
  corrmap,
  method = "LC",
  write_Ts = FALSE,
  filename_Ts = NA,
  write_emiss = FALSE,
  filename_emiss = NA,
  NDVI_veg = 0.8,
  NDVI_soil = 0.2,
  emiss_veg = 0.988,
  emiss_soil = 0.935,
  LC_emiss_matrix = NA
)

Arguments

thermal_orig

Map (SpatRaster) or path to geotiff file (chr) to the original land surface temperature map

thermal_uav

the ThermalUAV object corresponding to this thermal map. Is needed to extract parameters used in tuav_correct()

temp

indicate in which scale the thermal map represents the temperatures. Use "K" for Kelvin and "C" for degree Celcius.

corrmap

Map (SpatRaster) or path to geotiff file (chr) for emissivity correction. This can either be a landcover map, an NDVI map or a emissivity map.

method

Indicate which variable the correction map provides. Use "LC" when landcover is provided, "NDVI" if you want to use the NDVI method or "EM" when emissivity is provided.

write_Ts

(logical) use TRUE if the corrected thermal map must be written. Default = FALSE

filename_Ts

the path and filename where the corrected thermal map should be stored. If NA, it is written in the thermal path with label "_emis_corr". This variable is only used if write_Ts = TRUE

write_emiss

(logical) use TRUE if the emissivity map must be written. Default = FALSE

filename_emiss

the path and filename where the emissivity map should be stored. If NA, it is written in the thermal path with label "_emis". This variable is only used if write_emiss = TRUE

NDVI_veg

the NDVI value of vegetation. NDVI values above this threshold will receive an emissivity as defined in emiss_veg

NDVI_soil

the NDVI value of bare soil. NDVI values below this threshold will receive an emissivity as defined in emiss_soil

emiss_veg

the emissivity for vegetation, will be taken for an NDVI higher than NDVI_veg

emiss_soil

the emissivity for bare soil, will be taken for an NDVI lower than NDVI_soil

LC_emiss_matrix

a two column matrix with the first column the LC values and in the second the corresponding emissivties, only used if method = "LC"

Value

returns a recalculated thermal map corrected for spatially varying different emissivities.