METRIC.EB: Estimates Energy Balance using METRIC2010 Model

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

View source: R/water_METRIC.R

Description

Estimates Energy Balance using METRIC2010 Model

Usage

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METRIC.EB(image.DN, image.SR, WeatherStation, MTL, sat = "auto", thermalband,
  plain = TRUE, DEM, aoi, 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())

Arguments

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

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).

Details

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 Parameters

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

Author(s)

Guillermo F Olmedo, [email protected]

References

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

See Also

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

Examples

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### 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)

water documentation built on Nov. 17, 2017, 4:56 a.m.