SpecFit: SpecFit

In tommasojulitta/FieldSpectroscopyDP: R package for processing fieldspectroscopy data

Description

Compute the spectral sum of reflected radiance and fluorescence. Inverse mode returns the residual sum of squares. Forward mode returns the modeled radiance obtained by the sum of fluorescence and radiance.

Usage

SpecFit(x, E, L, fm, wl, run, O2band)

Arguments

x	numeric vector: parameter for gaussian and spline function
E	numeric vector: measured solar radiance
L	numeric vector: measued reflected radiance
fm	object of class "lm", deriving from first guess functoin
wl	numeric vector: wavelength vector
run	character value. If "inverse" residual sum f squares is returned. If "forward" modelled reflected radiance is returned.
O2band	character value: A or B referring to the oxygen absorption band where to compute the fluorescence estimation

Value

if "Inverse" mode the residual sum of squares is returned. If "Forward" mode a numeric vector containing the modeled radiance obtained is returned.

Author(s)

Tommaso Julitta, Mirco Migliavacca, Thomas Wutzler

Examples

  





data("FloX_data")


data("up_coeff")


data("dw_coeff")


data("wl_FloX")





L<-GetRadiance(DNSignal=FloX_data$L-FloX_data$dcL,IntegrationTime=FloX_data$IT_L/1000,RadCalCoeff=dw_coeff);L<-L[,1]


#Get Solar Radiance 


E<-GetRadiance(DNSignal=FloX_data$E-FloX_data$dcE,IntegrationTime=FloX_data$IT_E/1000,RadCalCoeff=up_coeff);E<-E[,1]


#Estimate fluorescence using iFLD method, used as first guess for Spectral Fitting Methods


iFLD_O2B<-iFLD(wl=wl_FloX,E,L,fwhm =0.4,O2band="B")


#Define range used for =2B band


range<-which(wl_FloX>684& wl_FloX<700)


#Subset the wavelength vector


WL<-wl_FloX[range]


E_sfm<-as.numeric(E[range])


L_sfm<-as.numeric(L[range])


fluoFG<-iFLD_O2B$Fluo


#Compute the first guess parameter both for reflectance and fluorescence


fg<-FirstGuess(wl = WL,L = L_sfm,E = E_sfm, fluo = iFLD_O2B$Fluo,O2band= "B")


#Model the relfected radiance using the first guess as input parameters


modelled_radiance<-SpecFit(fg$first_guess$FG,wl=WL,E=E_sfm,L=L_sfm,fm=fg$fm,run="forward",O2band ="B")


#plot results


x11()


plot(WL,L_sfm,type="l",ylab=expression("Radiance [W m"^-2* "sr"^-1* "nm"^-1*"]"))


lines(WL,modelled_radiance,col="red",xlab="WL [nm]")


legend("topleft",col=c("black","red"),lty=1,legend=c("Measured reflected radiance","Modeled reflected radiance"),box.col="white",lwd=2,cex=1.5)


box()





  

tommasojulitta/FieldSpectroscopyDP documentation built on March 12, 2020, 1:42 p.m.