IRISSeismic (version 1.6.6)

psdList2NoiseMatrix: Apply instrument correction to PSDs

Description

The psdList2NoiseMatrix function uses the snclq identifier associated with the first PSD in the list to obtain instrument correction information at the specified frequencies from the getEvalresp web service if instrumentation correction information is not supplied as an argument. This correction is applied to every PSD in the list and the now corrected PSD values are returned as a matrix.

Usage

psdList2NoiseMatrix(psdList, evalresp=NULL)

Value

A matrix is returned with one row for each instrument-corrected PSD and one column for each frequency bin.

Arguments

psdList

a list of PSDs generated by the psdList function

evalresp

dataframe of freq, amp, phase information matching output of getEvalresp, optional

Author

Jonathan Callahan

References

Seismic Noise Analysis System Using Power Spectral Density Probability Density Functions (McNamara and Boaz 2005)

See Also

McNamaraPSD, psdDF2NoiseMatrix, psdList, psdPlot, psdStatistics,

Examples

if (FALSE) {
# Create a new IrisClient
iris <- new("IrisClient", debug=TRUE)

# Get seismic data
starttime <- as.POSIXct("2011-05-05", tz="GMT") # 2011.125
endtime <- starttime + 1*24*3600
st <- getDataselect(iris,"IU","GRFO","--","BHE",starttime,endtime)

# Generate power spectral density for each hour long segment
psdList <- psdList(st)

# Convert into corrected "noiseMatrix"
noiseMatrix <- psdList2NoiseMatrix(psdList)

# Plot corrected PSDs
period <- 1/psdList[[1]]$freq
plot(period, noiseMatrix[1,], log='x', type='l',
     ylim=c(-200,-50),
     xlab="Period (Sec)", ylab="Power (dB)",
     main="Corrected PSDs")
     
for (i in seq(2:nrow(noiseMatrix))) {
  points(period, noiseMatrix[i,], type='l')
}
}