RSEIS (version 2.1-6)

get.corner: Get Corner Frequency: Linear Model

Description

Search for low frequency asymptote, corner frequency, and fall off slope of seismic spectrum.

Usage

get.corner(INfreq, INspec, dt, f1, f2, PLOT = FALSE, VERBOSE = FALSE)

Arguments

INfreq

frequency vector

INspec

spectrum

dt

deltaT

f1

low frequency for modeling, Hz

f2

High frequency for modeling, Hz

PLOT

logical, TRUE=plot

VERBOSE

TRUE=diagnostics

Value

• Model of 3 parameters, best fit.

Details

This routine does not assume any particular mathematical model. It searches for a three parameters that describe two lines that mimic the displacement spectrum. The search is done via least squares.

See Also

brune.doom

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)