IRISMustangMetrics (version 2.4.6)

stateOfHealthMetric: State of Health metrics

Description

The stateOfHealthMetric function extracts accumulated miniSEED quality flags and a measure of timing quality associated with the incoming seismic signal.

Usage

stateOfHealthMetric(st)

Value

A list of SingleValueMetric objects is returned.

Arguments

st

a Stream object containing a seismic signal

Author

Jonathan Callahan

Details

The miniSEED flags and timing_qual values are described in the SEED manual (http://www.fdsn.org/seed_manual/SEEDManual_V2.4.pdf).

Each Stream object contains "accumulators" with counts of the number of times each bit flag was set during the parsing of a miniSEED file. Metrics are reported for a subset of these flags as show in the code snippet below:

  # act_flags
  calibration_signal <- st@act_flags[1]
  timing_correction <- st@act_flags[2]
  event_begin <- st@act_flags[3]
  event_end <- st@act_flags[4]
  event_in_progress <- st@act_flags[7]
  
  # io_flags
  clock_locked <- st@io_flags[6]
                   
  # dq_flags
  amplifier_saturation <- st@dq_flags[1]
  digitizer_clipping <- st@dq_flags[2]
  spikes <- st@dq_flags[3]
  glitches <- st@dq_flags[4]
  missing_padded_data <- st@dq_flags[5]
  telemetry_sync_error <- st@dq_flags[6]
  digital_filter_charging <- st@dq_flags[7]

An additional "timing quality" metric gives the average value for the timing_qual value associated with each block of miniSEED data.

Examples

  if (FALSE) {
# Open a connection to IRIS DMC webservices
iris <- new("IrisClient")

# Get the waveform
starttime <- as.POSIXct("2012-01-24", tz="GMT")
endtime <- as.POSIXct("2012-01-25", tz="GMT")
st <- getDataselect(iris,"AK","PIN","","BHZ",starttime,endtime)

# Generate State of Health metrics and show the results
metricList <- stateOfHealthMetric(st)
dummy <- lapply(metricList, show)
  }