IRISSeismic (version 1.6.7)

getStation: Retrieve Station metadata from EarthScope

Description

The getStation method obtains station metadata from the EarthScope station web service and returns it in a dataframe.

Usage

getStation(obj, network, station, location, channel,
           starttime, endtime, includerestricted,
           latitude, longitude, minradius, maxradius)

Value

A dataframe with the following columns:

network, station, latitude, longitude, elevation, sitename, starttime, endtime

Rows are ordered by network-station.

Arguments

obj

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

starttime

POSIXct class specifying the starttime (GMT)

endtime

POSIXct class specifying the endtime (GMT)

includerestricted

optional logical identifying whether to report on restricted data

latitude

optional latitude used when specifying a location and radius

longitude

optional longitude used when specifying a location and radius

minradius

optional minimum radius used when specifying a location and radius

maxradius

optional maximum radius used when specifying a location and radius

Author

Jonathan Callahan

Details

The getStation method utilizes the station web service to obtain data for all stations that meet the criteria defined by the arguments and returns that data in a dataframe. Each row of the dataframe represents a unique station.

Each of the arguments network, station, location or channel may contain a valid code or a wildcard expression, e.g. "BH?" or "*". Empty strings are converted to "*". Otherwise, the ascii string that is used for these values is simply inserted into the web service request URL.

For more details see the web service documentation.

References

The EarthScope station web service:

https://service.earthscope.org/fdsnws/station/1/

This implementation was inspired by the functionality in the obspy get_stations() method.

https://docs.obspy.org/packages/autogen/obspy.clients.fdsn.client.Client.get_stations.html

See Also

IrisClient-class

Examples

# Open a connection to EarthScope webservices
iris <- new("IrisClient")

# Date of Nisqually quake
starttime <- as.POSIXct("2001-02-28",tz="GMT")
endtime <- starttime + 2*24*3600

# Use the getEvent web service to determine what events happened in this time period
result <- try(events <- getEvent(iris,starttime,endtime,6.0))
if (inherits(result,"try-error")) {
  message(geterrmessage())
} else {
  events

# biggest event is Nisqually
  eIndex <- which(events$magnitude == max(events$magnitude))
  e <- events[eIndex[1],]

# Which stations in the US network are within 5 degrees of the quake epicenter?
  result <- try(stations <- getStation(iris,"US","*","*","BHZ",starttime,endtime,
                            lat=e$latitude,long=e$longitude,maxradius=5))
  if (inherits(result,"try-error")) {
    message(geterrmessage())
  } else {
    stations
  }
}