brune.search: Search for Brune fit to displacement spectrum

In RSEIS: Seismic Time Series Analysis Tools

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)

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

Details

see paper by Lees and Lindley

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

Author(s)

Jonathan M. Lees<jonathan.lees.edu>

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)

RSEIS documentation built on Sept. 13, 2024, 1:09 a.m.