radiometric.surface.temp: Radiometric Surface Temperature

In lhmet-forks/bigleaf: Physical and Physiological Ecosystem Properties from Eddy Covariance Data

Description

Radiometric surface temperature from longwave radiation measurements.

Usage

radiometric.surface.temp(data, LW_up = "LW_up", LW_down = "LW_down",
  emissivity, constants = bigleaf.constants())

Arguments

data	Data.frame or matrix containing all required input variables
LW_up	Longwave upward radiation (W m-2)
LW_down	Longwave downward radiation (W m-2)
emissivity	Emissivity of the surface (-)
constants	sigma - Stefan-Boltzmann constant (W m-2 K-4) Kelvin - conversion degree Celsius to Kelvin

Details

Radiometric surface temperature (Trad) is calculated as:

Trad = ((LW_up - (1 - ε)*LW_down) / (σ ε))^(1/4)

Value

a data.frame with the following columns:

Trad_K

Radiometric surface temperature (K)

Trad_degC

Radiometric surface temperature (degC)

References

Wang, W., Liang, S., Meyers, T. 2008: Validating MODIS land surface temperature products using long-term nighttime ground measurements. Remote Sensing of Environment 112, 623-635.

Examples

# determine radiometric surface temperature for the site DE-Tha in June 2014 
# assuming an emissivity of 0.98.
# (Note that variable 'LW_down' was only included for the DE-Tha example dataset
# and not for the others due restrictions on file size) 
Trad <- radiometric.surface.temp(DE_Tha_Jun_2014,emissivity=0.98)
summary(Trad)

lhmet-forks/bigleaf documentation built on Aug. 4, 2020, 12:08 a.m.