SAGE Facility MUSTANG metrics Web Service Documentation

This metric shows the continuous time spans encountered within a 24-hour window calculated at query time. It processes the times of data availability based on information stored in the rapidly-accessible IRIS SEED and PH5 archive database indexes (ts_index), as returned by the service.iris.edu/fdsnws/availability and service.iris.edu/ph5ws/availability web service.

The ts_channel_up_time metric is currently a prototype that will eventually become a standard MUSTANG metric.

Data gaps can indicate problems with data transmission configuration or performance, power cycling or other equipment down time, or data loss after transmission. The metric helps to pinpoint where continuous data can be found and can provide a good indication of how gappy the data is and when.

Traces – one N.S.L.C (Network.Station.Location.Channel) per measurement
Window – from start time to the end time of the request
Data Source – IRIS miniSEED archive database time series index (ts_index)

SEED Channel Types – All Time Series Channels

• Request availability web service trace extents for 24 hours of a single N.S.L.C.
• Assume that missing data at the beginning of the day is a gap that begins at the day boundary and ends when the data begins.
• Assume that missing data at the end of the day is a gap that begins after the last data sample and ends at the day boundary.
  • Calculate the end time of each data segment:
    

    endtime(x) = starttime(x) + ( (num_samples(x) - 1) / sample_rate)
    

• For x entries/data segments returned,
  • Calculate length of up-time for each segment:
    

    segdt(x) = endtime(x) – starttime(x)
    

  • Report segdt(x), starttime(x), and endtime(x) when segdt(x) > 0

value – the data up-time in seconds
target – the trace analyzed, labeled as N.S.L.C.Q (Network.Station.Location.Channel.Quality)
start – the start time of the continuous extent (UTC), or start of day
end – the end time of the continuous extent (UTC), or end of day
lddate – UTC date/time the measurement was made

If the user specified request end date does not include hour:min:sec, then it defaults to 00:00:00

• Robert Casey