coldhot: Automatic computation of hot and cold pixels from Radiometric...

In gowusu/sebkc: The Surface Energy Balance and Crop Coefficient Estimation with R

Automatic computation of hot and cold pixels from Radiometric Surface Temperature (Ts)

Description

This function computes temperature coordinates of a hot and cold pixels based on only Surface Temperature. This function uses ranges of temperature.

Usage

coldhot(Tmin, Tmax, Ts = NULL, folder = NULL, welev = NULL)

## Default S3 method:
coldhot(Tmin, Tmax, Ts = NULL, folder = NULL,
  welev = NULL)

Arguments

Tmin	Numeric. Minimum surface Temperature in map units (eg. Kilvin) that you want computation from. You can keep changing untill you get your desired values
Tmax	Numeric. Maximum surface Temperature in map units (eg. Kilvin) that you want computation from. You can keep changing untill you get your desired values
Ts	A RasterLayer data that indicates radiometric surface temperature values from remote sensing image, preferably in Kelvin (K). You can also point to raster file on your computer.
folder	An original directory of the images that contains all landsat 5,7 or 8 bands and metadata. At the moment only Landsat folder is supported
welev	Weather station elevation in meters

Details

The function first divides the selected area into a number of clusters. The mean and standard deviations are computed. The cluster means with the lowest standard deviations and qualifying for upper (Ts) and lower (NDVI) limits (see above) are selected. The provided upper and lower probabilities are also used to select the final Ts.

Value

• Ts: The selected or input Ts

• Tshot: The Temperature of hot pixel

• Tscold: The Temperature of cold pixel

• xyhot: combined x and y coordinates

• candidates: The similar candidates' pixels that can be used

Author(s)

George Owusu

References

Allen, R. G., Burnett, B., Kramber, W., Huntington, J., Kjaersgaard, J., Kilic, A., Kelly, C., & Trezza, R. 2013. Automated Calibration of the METRIC-Landsat Evapotranspiration Process. JAWRA Journal of the American Water Resources Association, 49(3): 563-576.

See Also

coldTs, hotTs, coldT2

Examples

## Not run: 
 folder=system.file("extdata","stack",package="sebkc")
  model=coldhot(Tmin=300,Tmax=310,folder=folder,welev=170)
  spplot(model$Tshot)
  spplot(model$Tscold)
  modauto=sebal(folder = folder,welev = 380,xycold=model$xycold,xyhot=model$xyhot)
## End(Not run)

gowusu/sebkc documentation built on July 28, 2023, 11:44 a.m.