Summary
The portion of data available for each day is represented as a percentage. 100% data available means that data for the reported start and end time is complete.
Uses
percent_availability values can be averaged to give data completeness for a channel over an integer number of days. The metric also indicates whether or not data for a given channel/day is available for request from the IRIS DMC.
Data Analyzed
Traces – one N.S.L.C (Network.Station.Location.Channel) per measurement
Window – 24 hours starting at 00:00:00 UTC
Data Source – IRIS miniSEED archive or IRIS PH5 archive
SEED Channel Types – ?H?, ?L?, ?N?, ?G?, ?P?, VM? | High Gain, Low Gain, Accelerometer, Gravimeter, Geophone, Mass Channels
Algorithm
- Request 24 hours of data for a single N.S.L.C.
- Sum the data gaps in seconds for this period of time.
- Calculate the percentage from the ratio of data found (omitting gaps) to data expected for the full day:
percent_available = 100 - ( 100 * gap_seconds / total_seconds )
Metric Values Returned
value – availability of data expressed as a percentage
target – the trace analyzed, labeled as N.S.L.C.Q (Network.Station.Location.Channel.Quality)
start – beginning of the data day requested (00:00:00 UTC)
end – end of the data day requested (truncated as 23:59:59 UTC)
lddate – date/time the measurement was made and loaded into the MUSTANG database (UTC)
