R: Search for Brune fit to displacement spectrum

brune.search {RSEIS} | R Documentation

## 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)

[Package RSEIS version 3.7-4 Index]