The targets web service returns a list of targets having measurements for the specified metric. Targets can be filtered by station, network, etc. This channel list can be passed to the measurements service using command line tools such as curl.
Below is a full list of service parameters and their usage.
Start with base URL
append standard query pattern
/query? (metric) [snclq-filter] [server-response]
metric :: (metric=<data_latency | max_gap | max_overlap | max_stalta | num_gaps | num_overlaps | percent_availability | etc.....>) snclq-filter :: [net[work]=<network>] [sta[tion]=<station>] [loc[ation]=<location>] [chan[nel]=<channel>] [qual[ity]=<quality>] server-response :: [nodata=< HTTP code >]
Query parameters are joined by ampersands &, without blank space (see the sample queries).
Which targets have STA/LTA measurements?
Stations in the GSN, showing max_gap values?
Detailed Descriptions of each Query Parameter
||Retrieve targets having measurements for the specified metric. Select the Current list of all metrics button above for metrics names.||string|
|channel options (SNCLQ filter)|
||Specify SEED network code. If a virtual network code is specified, the
||Specify SEED station code. Accepts wildcards and lists||any||string|
||Specify SEED location code. Use
||Specify SEED channel code. Accepts wildcards and lists||any||string|
||Specify SEED quality indicator. Most metrics are calculated using M quality data. (Latency metrics operate on D and R quality data.) Accepts wildcards and lists||any||string|
||Specify which HTTP status code is returned when no results are found.||404||204 or 404|
By default, FDSN services return an HTTP code of 204 when a request is “successful”, but there were no matching results. This behavior allows automated systems to know the difference between a successful request (with no data) from an incorrect request (bad parameter names, invalid URL, etc). Since no content is returned, the page on the web browser will not change. To force the service to return a 404, add the query parameter
The question mark
? represents any single character (exactly one), while the asterisk
* represents zero or more characters.
Multiple items may also be retrieved using a comma separated list. Wildcards may be included in the list. For example, with channel codes: