SAGE Facility MUSTANG metrics Web Service Documentation

This metric lists the duration in seconds and beginning and end times of “continuous” data segments for a single channel. In the context of this metric, continuous means that no gaps exceed 1 second.

These measurements can help locate time spans when channel data is missing from the archive or identify data segments that can be used for research applications requiring long continuous time series.

Measurements for this metric are incomplete. When using rrds, use the metric ts_channel_uptime in place of this metric.

Traces – one N.S.L.C (Network.Station.Location.Channel). Traces with multiple segments during the time window will have multiple measurements
Window – 24 hours starting at 00:00:00 UTC, but measurements for consecutive days are merged into a single entry when the data is continuous
Data Source – IRIS SEED archive

SEED Channel Types – None

• Request time series data for the user-specified N.S.L.C, start and end times.
• Exclude any overlapping data.
• Create an array of start and end times for returned data having x data segments:
  

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

• Calculate gap sizes:
  

   gaps(x) = endtime(x-1) – starttime(x) 
  

• Consider segments separated by gaps of less than 1 second length as a single segment and calculate the duration of each data segment:
  

  duration(x) = endtime(x) – starttime(s)
  

• Omit segments shorter than 30 seconds long.

value – duration of a continuous data segment in seconds
target – the trace analyzed, labeled as N.S.L.C.Q (Network.Station.Location.Channel.Quality)
start – beginning the first continuous data segment of the day requested in UTC
end – end of a continuous data segment or beginning of the following day (00:00:00) in UTC
lddate – date/time the measurement was made and loaded into the MUSTANG database (UTC)

Time spans labeled “continuous” by this metric may contain gaps smaller than 1 second. To ensure continuity to the sample interval, the metric num_gaps must also be zero. Additional data segments shorter than 30 seconds may exist in the archive but not be listed by channel_up_times.

• Robert Casey