getEvalresp: Retrieve instrument response information from IRIS DMC

Description

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

Usage

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

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")

Value

For output="fap", a dataframe with columns named:
freq, amp, phase
For output="cs", a dataframe with columns named:
freq, real, imag

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 http://service.iris.edu/fdsnws/dataselect/1/{dataselect documentation}.)

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

References

The IRIS DMC evalresp webservice: