SNRMetric | R Documentation |

The SNRMetric() function calculates the Signal-to-Noise Ratio of a seismic trace by one of several named algorithms.

SNRMetric(st, algorithm, windowSecs)

`st` |
a |

`algorithm` |
a named algorithm to use for calculating SNR (default= |

`windowSecs` |
width (seconds) of the full window used in SNR calculations (default= |

Seismic signals in the Stream must be without gaps, *i.e.* contained within a single Trace.

`algorithm="splitWindow"`

This algorithm uses the midpoint of the seismic signal as the border between noise to the left of the midpoint and signal to the right. The value for signal-to-noise is just the rmsVariance calculated for windowSecs/2 seconds of data to the right of the midpoint divided by the rmsVariance for windowSecs/2 seconds of data to the left of the midpoint.

No other algorithms have been vetted at this point.

A list with a single `SingleValueMetric`

object is returned.

Jonathan Callahan jonathan@mazamascience.com

## Not run: # Open a connection to IRIS DMC webservices iris <- new("IrisClient") # Get an hour long waveform centered on a big quake starttime <- as.POSIXct("2010-02-27 06:16:15",tz="GMT") endtime <- as.POSIXct("2010-02-27 07:16:15",tz="GMT") st <- getDataselect(iris,"IU","ANMO","00","BHZ",starttime,endtime) tr <- st@traces[[1]] # Calculate the SNR metric and show the results metricList <- SNRMetric(st) dummy <- lapply(metricList, show) ## End(Not run)

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