METRIC.EB: Estimates Energy Balance using METRIC2010 Model
In water: Actual Evapotranspiration with Energy Balance Models

Description Usage Arguments Details Extra Parameters Author(s) References See Also Examples

Estimates Energy Balance using METRIC2010 Model

METRIC.EB(image.DN, image.SR, WeatherStation, MTL, sat = "auto", thermalband,
  plain = TRUE, DEM, aoi, G.method = "Tasumi", alb.coeff = "Tasumi",
  LST.method = "SC", LAI.method = "metric2010", L = 0.1,
  Zom.method = "short.crops", anchors.method = "CITRA-MCB", anchors,
  n = 1, ETp.coef = 1.05, Z.om.ws = 0.0018, verbose = FALSE,
  extraParameters = vector())

`image.DN`	raw imagen in digital counts to evaluate
`image.SR`	L8 ONLY. Surface reflectance imagen. water package does not include a model to calculate surface reflectance for Landsat 8 images. Landsat 8 users should download precalculated surface reflectances from espa website (espa.cr.usgs.gov).
`WeatherStation`	Weather Station data, can be a waterWeatherStation object
`MTL`	Landsat metadata file
`sat`	Landsat satellite version. "L7" or "L8"
`thermalband`	Landsat low gain thermalband
`plain`	Logical. If TRUE surface is assumed plain
`DEM`	Digital Elevation Model of the study area. Not needed if plain = TRUE
`aoi`	SpatialPolygon object with limits of Area of interest
`G.method`	method used for the G estimation. Currently implemeted are "Tasumi" for Tasumi,2003 or "Bastiaanssen" for Bastiaanssen, 2000
`alb.coeff`	coefficient to transform narrow to broad band albedo. See Details.
`LST.method`	Method for land surface temperature estimation. "SC" for single channel or "SW" for split window algorithm. "SW" is only available for L8. See `water::surfaceTemperature`
`LAI.method`	Method used to estimate LAI from spectral data. See Details.
`L`	L value for SAVI calculation
`Zom.method`	method selected to calculate momentum roughness length. Use "short.crops" for short crops methods from Allen et al (2007); "custom" for custom method also in Allen et al (2007); Or "Perrier" to use Perrier equation as in Santos et al (2012) and Pocas et al (2014).
`anchors.method`	method for the automatic selection of the anchor pixels.
`anchors`	data.frame or SpatialPointsDataFrame with the anchor pixels. The data frame must include a "type" column with "hot" and "cold" values.
`n`	number of pair of anchors pixels to calculate
`ETp.coef`	ETp coefficient usually 1.05 or 1.2 for alfalfa
`Z.om.ws`	momentum roughness lenght for WeatherStation. Usually 0.0018 or 0.03 for long grass
`verbose`	Logical. If TRUE will print aditional data to console
`extraParameters`	Extra parameters for the non default methods. i.e. Zom.method = "Perrier", needs two extra parameters: fLAI, h. See help(momentumRoughnessLength).

There are differents models to convert narrowband data to broadband albedo. You can choose alb.coeff ="Tasumi" to use Tasumi et al (2008) coefficients, calculated for Landsat 7; alb.coeff ="Liang" to use Liang Landsat 7 coefficients or "Olmedo" to use Olmedo coefficients for Landsat 8.

Extra Paramenters for functions inside METRIC.EB() include: * for momentumRoughness when Zom.method = "Perrier": fLAI, h. * for calcAnchors(): minDist, WSbuffer, deltaTemp

Guillermo F Olmedo, guillermo.olmedo@gmail.com

R. G. Allen, M. Tasumi, and R. Trezza, "Satellite-based energy balance for mapping evapotranspiration with internalized calibration (METRIC) - Model" Journal of Irrigation and Drainage Engineering, vol. 133, p. 380, 2007 González, Arturo & Hay, Christopher & Kjaersgaard, Jeppe & Neale, Christopher. (2015). Use of Remote Sensing to Generate Crop Coefficient and Estimate Actual Crop Evapotranspiration. 10.13031/aim.20152190105.

Other METRIC model functions: METRIC.G, METRIC.Rn

### Data preparation
library(water)
aoi <- createAoi(topleft = c(500000, -3644000), bottomright = c(526000, -3660000))
raw_data_folder <- system.file("extdata", package="water")
image <- loadImage(path=raw_data_folder, aoi=aoi, sat="L8")
image.SR <- loadImageSR(path=raw_data_folder, aoi=aoi)
csvfile <- system.file("extdata", "INTA.csv", package="water")
MTLfile <- system.file("extdata", "LC82320832016040LGN00_MTL.txt", package="water")
## Not run: 
WeatherStation <- read.WSdata(WSdata = csvfile, 
                              datetime.format =  "%Y/%m/%d %H:%M", 
                              columns = c("datetime", "temp",
                                          "RH", "pp", "radiation", "wind"), 
                              lat=-33.00513, long= -68.86469, elev=927, height= 2,
                              MTL=MTLfile)
                              
### LSEB with default methods and no extra parameters                               
Energy.Balance <- METRIC.EB(image.DN = image, image.SR = image.SR,
                            plain=TRUE, aoi=aoi, n = 5, WeatherStation = WeatherStation, 
                            ETp.coef = 1.2, sat="L8", alb.coeff = "Olmedo", LST.method = "SW", 
                            LAI.method = "metric2010", Z.om.ws = 0.03, MTL = MTLfile)
                            
                            
### LSEB with "Perrier" method for Zom and extra parameters                               
Energy.Balance <- METRIC.EB(image.DN = image, image.SR = image.SR,
                            plain=TRUE, aoi=aoi, n = 5, WeatherStation = WeatherStation, 
                            ETp.coef = 1.2, sat="L8", alb.coeff = "Olmedo", LST.method = "SW", 
                            LAI.method = "metric2010", Zom.method = "Perrier", Z.om.ws = 0.03, 
                            MTL = MTLfile, extraParameters = c(fLAI = 0.5, h = 1.8) ) 

## End(Not run)