getPsdMetrics: Retrieve measurements from the MUSTANG BSS

Description

The getPsdMetrics method of the IrisClient makes a request of the MUSTANG BSS (Backend Storage System) and returns a dataframe containing Power Spectral Density (PSD) measurements.

Usage

getPsdMetrics(obj, network, station, location, channel, 
                   starttime, endtime, url)

Arguments

obj

an IrisClient object

network

a character string with the two letter seismic network code

station

a character string with the station code

location

a character string with the location code

channel

a character string with the three letter channel code

starttime

a POSIXct class specifying the starttime (GMT)

endtime

a POSIXct class specifying the endtime (GMT)

url

optional url of the BSS measurements service

Value

A dataframe with the following columns:
target, starttime, endtime, frequency, amplitude, phase

Details

The default BSS measurement service when url is not specified is:

http://service.iris.edu/mustang/measurements/1/query?

The metric name is automatically specified by appending metric=psd to this url.

Data returned from the BSS are converted into an Rdataframe.

Error returns from the BSS will stop evaluation and generate an error message.

Examples

Run this code

# Open a connection to IRIS DMC webservices (including the BSS)
iris <- new("IrisClient", debug=TRUE)

starttime <- as.POSIXct("2012-01-24", tz="GMT")
endtime <- as.POSIXct("2012-01-25", tz="GMT")

# Get the measurement XML
xml <- getPsdMetrics(iris,"AK","PIN","","VEA",
                          starttime,endtime,metricName="sample_mean",
                          url="http://service.iris.edu/mustang/measurements/1/query?")