Description Usage Arguments Details Extra Parameters Author(s) References See Also Examples
Estimates Energy Balance using METRIC2010 Model
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | 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 |
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()
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | ### 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)
|
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