wcm_sim: Simulate backscattering coefficient using WCM model

In WCM: Water Cloud Model (WCM) for the Simulation of Leaf Area Index (LAI) and Soil Moisture (SM) from Microwave Backscattering

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

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

# 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 for ‘nlc <- 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 for ‘k <- nls(w ~ wcm_sim(X, Y, theta, A, B, C, D), control = nlc, ’
Warning message:
In example(y <- predict(k)) : no help found for ‘y <- predict(k)’

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