getEvalresp: Retrieve instrument response information from EarthScope

Description

The getEvalresp method obtains instrument response data from the EarthScope evalresp webservice.

Usage

getEvalresp(obj, network, station, location, channel,
            time, minfreq, maxfreq, nfreq, units, output, spacing)

Value

For output="fap", a dataframe with columns named:

freq, amp, phase

For output="cs", a dataframe with columns named:

freq, real, imag

Arguments

obj: an IrisClient object
network: character string with the two letter seismic network code
station: character string with the station code
location: character string with the location code
channel: character string with the three letter channel code
time: POSIXct class specifying the time at which response is evaluated (GMT)
minfreq: optional minimum frequency at which response will be evaluated
maxfreq: optional maximum frequency at which response will be evaluated
nfreq: optional number of frequencies at which response will be evaluated
units: optional code specifying unit conversion
output: optional code specifying output type (default="fap")
spacing: optional code specifying spacing, accepted values are "lin" or "linear", "log" or "logarithmic" (default="log")

Author

Jonathan Callahan jonathan@mazamascience.com

Details

The evalresp webservice responds to requests with data that can be used to remove instrument response from a seismic signal.

Each of network, station or channel should contain a valid code without wildcards. The ascii string that is used for these values is simply passed through to evalresp.

If the location argument contains an empty string to specify a 'blank' location code, a location code of "--" will be used in the dataselect request URL. (See dataselect documentation.)

The response from evalresp is converted into a dataframe with rows in order of increasing frequency.

References

The EarthScope evalresp webservice:

https://service.earthscope.org/irisws/evalresp/1/