RSEIS (version 4.2-4)

brune.search: Search for Brune fit to displacement spectrum

Description

Model of the spectrum of a seismic arrival. Uses Brune's Model.

Usage

brune.search(infreq, inspec, f1, f2, omega0, fcorn, tstar0, gamma)

Value

list(omega0=omega0,tstar0=tstar3[3] , fc=fcorn, alpha=0, gamma=gam3[3])

omega0

low frequency asymptote

fc

corner frequency

tstar0

t*

gamma

gamma

alpha

alpha parameter

chisqrd

chi-squared misfit over region of fitting

Arguments

infreq

vector of frequencies

inspec

spectrum

f1

low frequency, Hz

f2

high frequency, Hz

omega0

initial starting low frequency asymptote

fcorn

initial starting corner frequency

tstar0

initial starting t*

gamma

initial starting gamma

Author

Jonathan M. Lees<jonathan.lees.edu>

Details

see paper by Lees and Lindley

References

Lees and Lindley

See Also

MTM

Examples

data(CE1)

####   set frequency range for modeling
f1  <-  0.01
f2  <-  14.0

##  set up data and parameters
amp  <-   CE1$y
len2  <-  2*next2(length(amp))
a  <-  list(y=amp, dt=CE1$dt)

Spec  <- MTMdisp(a, f1=f1, f2=f2, len2=len2, PLOT=FALSE )
 
lspec  <-  Spec$displ

###  get initial estimate of parameters
xc  <-  get.corner(  Spec$f , lspec, dt, f1, f2, PLOT=FALSE)

jmod  <-  brune.search(Spec$f, lspec, f1, f2,
                 xc$omega0, xc$corn, xc$tstar0, 2.0)