wcm_sim: Simulate backscattering coefficient using WCM model

Description Usage Arguments Value Examples

View source: R/wcm_sim.R

Description

This function can be used to simulate the backscattering coefficient using WCM. This function can be called in nls function for generation of model coefficients (A,B,C,D).

Usage

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wcm_sim(X, Y, theta, A, B, C, D)

Arguments

X

In situ LAI or vegetation descriptor

Y

In situ SM soil moisture

theta

incident angle of Satellite sensor

A

fitted coefficient for WCM using non linear least squre using in situ data

B

fitted coefficient for WCM using non linear least squre using in situ data

C

fitted coefficient for WCM using non linear least squre using in situ data

D

fitted coefficient for WCM using non linear least squre using in situ data

wcm_sim

is simulated backscattering coefficient

Value

simulated backscattering coefficient

Examples

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# For single value.
 n <- wcm_sim(4,.3,48.9,-9.596695,-0.005331,-11.758309,0.011344)

#For list of value
X<-c(5.34, 4.34, 4.32, 4.12, 4.17, 3.58, 5.39, 5.66, 5.47, 5.73, 5.76, 5.93, 4.91, 5.36, 6.15,
     4.56, 5.44, 6.54, 6.20, 6.34, 5.56, 5.88, 7.34, 5.74, 4.81, 5.73, 3.63, 4.61, 4.76, 4.02)
Y<-c(35.0, 26.0, 18.0, 13.0, 18.0, 22.0, 19.0, 16.5, 20.0, 24.0, 24.0, 21.0, 13.0, 22.0, 25.0,
     24.0, 30.0, 23.0, 18.0, 17.6, 15.0, 17.0, 27.0, 22.0, 21.0, 15.0, 15.0, 18.0, 31.0, 10.0)

w<-c(-9.604, -11.648, -11.556, -11.556, -11.090, -10.444, -10.444, -10.042,  -9.200,  -9.750,
       -9.200,  -9.200,  -9.812,  -9.972,  -8.938,  -9.200,  -8.198,  -7.722,  -7.348,  -7.348,
       -8.198, -10.082,  -6.870,  -8.104,  -8.732,  -7.830, -10.686, -10.964, -10.976, -10.976)

theta<-48.9
example(nlc<-nls.control(maxiter = 50000, tol = 1e-05, minFactor = 1/100000000000,
printEval = FALSE, warnOnly = FALSE))
example(k<-nls(w~wcm_sim(X,Y,theta,A,B,C,D),control=nlc,
 start=list(A= 0.01,B=0.01,C=-21,D= 0.00014),trace = T))
example(y<-predict(k))
n <- wcm_sim(X,Y,theta,-9.596695,-0.005331,-11.758309,0.011344)

Example output

Warning message:
In example(nlc <- nls.control(maxiter = 50000, tol = 1e-05, minFactor = 1/1e+11,  :
  no help found fornlc <- nls.control(maxiter = 50000, tol = 1e-05, minFactor = 1/1e+11,Warning message:
In example(k <- nls(w ~ wcm_sim(X, Y, theta, A, B, C, D), control = nlc,  :
  no help found fork <- nls(w ~ wcm_sim(X, Y, theta, A, B, C, D), control = nlc,Warning message:
In example(y <- predict(k)) : no help found fory <- predict(k)

WCM documentation built on April 1, 2020, 5:10 p.m.

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