getMustangMetrics {IRISMustangMetrics}

Retrieve measurements from the MUSTANG BSS

Description

The getMustangMetrics method of the IrisClient makes a request of the MUSTANG database and returns a dataframe containing metrics measurements. This function is an alias of the getGeneralValueMetrics function.

Usage

getMustangMetrics(obj, network, station, location, channel, 
                           starttime, endtime, metricName, ...)

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, can be "" for wildcard all

channel

a character string with the three letter channel code, can be "" for wildcard all

starttime

a POSIXct class specifying the starttime (GMT)

endtime

a POSIXct class specifying the endtime (GMT)

metricName

a character string containing one or more comma separated metric names

...

optional arguments constraint a character string containing value constraints url optional url of the MUSTANG measurements service

Details

A blank location code should be specified as location="--"; Using location="" will return all location codes.

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

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

Data returned from MUSTANG are converted into an R dataframe.

The optional constraint parameter is used to add constraints to the query as defined in the MUSTANG measurements web service documentation. Any string passed in with the constraint parameter will be appended to the request url following an ampersand.

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

Value

A dataframe with the following columns:

~metricName~, value, additional values,  snclq, starttime, endtime, loadtime

The loadtime column contains the time at which this record was loaded into the database.

The dataframe rows will be sorted by metricName and increasing starttime.

Note

The database was originally populated with a version of this package that always assigned quality to be 'B'. Later versions obtained the quality from the miniSEED packet (typically 'M'). Because of this it is possible to have duplicate entries that only differ in the Q part of their snclq. To avoid double counting, when the webservice return contains two records whose only difference is the quality code portion of the of the snclq, only the record with the later loaddate will be used in the dataframe.

Author(s)

Jonathan Callahan [e-mail]

See Also

createBssUrl, getPsdMetrics

Examples

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

starttime <- as.POSIXct("2016-08-01", tz="GMT")
endtime <- starttime + 30*24*3600
metricName <- "orientation_check"

# Get the measurement dataframe
juneStats <- tryCatch(getMustangMetrics(iris,"IU","ANMO","","BH[12Z]",starttime,endtime,metricName),
                      error=function(e) {message(e)})
juneStats