Thread: Upcoming changes to the MUSTANG on-demand availability metrics ("ts" metrics)

Started: 2021-06-02 16:31:28
Last activity: 2021-06-10 19:07:37
Dear MUSTANG Users,

Next week on Thursday, June 10, ~10AM PDT (17:00 UTC), we will be implementing changes to the MUSTANG on-demand availability metrics ("ts" metrics), calculated from the availability web service output. The metrics that are affected are:

ts_channel_gap_list (new metric)

List of changes:

1. The ts metrics will return values for data available through our PH5WS web services as well as our FDSNWS web services.

2. The ts metrics will incorporate metadata information from the PH5WS and FDSNWS station web services. This will allow the metrics to report values of, for example, ts_percent_availability=0 when no data exists and no trace extents are returned from the availability services.

3. The ts metrics output will be bounded by the current time, for request dates that extend into the future. It will not report future values.

4. For the ts metrics that report values for daily 24-hour windows (ts_gap_length, ts_max_gap, ts_num_gaps, ts_percent_availability), output will be bounded by the station-channel metadata extents for queries with requested start and/or end times that exceed those extents. For metadata that starts mid-day, the first reported day with values is that same day starting at 00:00:00. For metadata that ends mid-day, the last reported day is that same day ending at 23:59:59.

5. For the ts metrics that report "total" values (ts_gap_length_total, ts_max_gap_total, ts_num_gaps_total, ts_percent_availability_total), metric values will be calculated across the entire user-requested timespan if the station-channel has metadata intersecting that timespan.

6. We are introducing a new metric, ts_channel_gap_list. This metric is the inverse of the ts_channel_continuity metric which reports the duration of trace extents returned by the availability service. ts_channel_gap_list returns the duration, start, and end times of the gaps that exist over the requested time period, bounded by the station-channel metadata.

7. bug fixes:
a. ts metrics will calculate correct values in the rare case when the availability service returns trace extents with sample rates of 0 sps. The code now removes these sample rate=0 extents before calculating metric values.
b. Requests for format=json when ts_num_gaps or ts_num_gaps_total is in a metric list that includes another ts metric earlier in the list will output results, instead of reporting an error.

IRIS Quality Assurance

18:16:12 v.615f2d0b