R: convolve for Ground roll

sigconvGR {RSEIS} | R Documentation

## convolve for Ground roll

### Description

convolve a set of spikes for extended ground roll. This is a special case of sigconv.

### Usage

    sigconvGR(wigmat, wavepulse, dt)

### Arguments

`wigmat` | matrix of traces with spikes
`wavepulse` | wavelet
`dt` | sampling interval

### Details

This is similar to the sigconv program but it assumes that the ground roll is extrened in time and space as the wave expands.

### Value

Matrix, waveforms

### Note

the program spreads the sinusoidal wavelet along a band to simulate ground-roll head wave noise.

### Author(s)

Jonathan M. Lees<jonathan.lees@unc.edu>

### See Also

wiggleimage, symshot1, genrick, sigconv

### Examples

    S1 <- symshot1()
    dt <- S1$dt
    ###########    these are the reflections S1$GRrec

    d <- dim(S1$smograms)
    G1 <- matrix( rep(0, length=d[1]*d[2]), ncol=d[2], nrow=d[1])

    ###   these are the refractions S1$THEORY$trefrac
    p <- round( S1$THEORY$trefrac[1,]/S1$dt );
    G1[cbind(p , 1:d[2])  ] <- 1

    #### plot the spikes
    wiggleimage(0.1*G1, dt = -S1$dt, dx = S1$x, col = "black")

    grlen <- floor(.6/dt)
    fgr <- 10
    tape <- applytaper( rep(1, grlen), p = 0.2)
    tgr <- seq(from=0, by=dt, length=grlen)
    siggr <- tape*sin(2*pi*fgr*tgr)

    ##############  convolve the wavelet with the set of spikes
    H1 <- sigconvGR(G1, siggr, dt)

    ############  plot
    wiggleimage(0.1*H1, dt = -S1$dt, dx = S1$x, col = "black")

[Package RSEIS version 3.7-4 Index]