International Federation of Digital Seismograph Networks

Thread: WG-II agenda update

Started: July 19, 2013, 12:53 p.m.
Last activity: July 19, 2013, 12:53 p.m.
Sleeman, Reinoud (KNMI)
July 19, 2013, 12:53 p.m.

Dear WG-II members,

please find the draft agenda for the upcoming meeting in Gothenburg,
scheduled Tuesday July 23, 12:00 – 13:30 (room F3).

1) Status of StationXML at different data centers
Please provide me with the status at your datacenter (if you did not yet)
2) Proposal by IRIS-DMC for simple text output format to be an optional
output for FDSN web services (see below)
3) Suggestions by IRIS-DMC for StationXML changes, see list below.
4) Multiple network codes for joint stations
5) Data centers interconnection: status in Europe

Please feel free to add relevant items to the list.


____________________________________ Proposed text output:

---- Network level output
#Network | Description | StartTime | EndTime | TotalStations
IU|Global Seismograph Network (GSN - IRIS/USGS)|1988-01-01T00:00:00|2500-12-12T23:59:59|254

---- Station level output
#Network | Station | Latitude | Longitude | Elevation | SiteName | StartTime | EndTime
IU|ANMO|34.94591|-106.4572|1820.0|Albuquerque, New Mexico, USA|2008-06-30T20:00:00|2599-12-31T23:59:59

---- Channel level output
#Network | Station | Location | Channel | Latitude | Longitude | Elevation | Depth | Azimuth | Dip | Instrument | Scale | ScaleFreq | ScaleUnits | SampleRate | StartTime | EndTime
IU|ANMO|00|LHZ|34.945981|-106.457133|1671.0|145.0|0.0|-90.0|Geotech KS-54000 Borehole Seismometer|3.27508E9|0.02|M/S|1.0|2012-03-12T20:28:00|2599-12-31T23:59:59

________________________________________________ StationXML suggested changes:

1) Station::CreationDate should be optional. This value denotes when a station/site was
originally installed and is distinct from the startDate attribute used to note the station
epoch start. There is no need for it to be required, it cannot be retained in conversions
and many data centers do not have this information forcing them to set it to, e.g., the startDate.

2) Use xs:double type instead of xs:decimal type for ApproximationLowerBound, ApproximationUpperBound
and MaximumError values (in PolynomialType::ApproximationType). For consistency, xs:double is used
for most other floating point values in the schema. Also xs:double allows values in scientific notation.

3) Change startDate attribute (for Network, Station and Channel) to be optional. The issue is that
startDate for Network is not commonly known or contained in SEED, forcing the insertion of potentially
bad dates.

4) Remove redundancy of FrequencyType and SampleRateType, they are effectively the same except units
described as HERTZ versus SAMPLES/S. SampleRateType can be replaced with FrequencyType. If that is
not desired the DecimationType::InputSampleRate should be changed to SampleRateType for consistency.

5) Include data availability elements described in the fdsn-station+availability-1.0.xsd extension schema
as optional elements of the main schema.

6) Add "updated" attribute to important response elements (PolesZeros, Coefficients, etc.) and other
important elements (Latitude, Longitude, Azimuth, etc.) to track when these details were last changed.
Required or optional? Required means no backwards compatibility.

7) Add an optional ChannelGroup element to explicitly define groups of channels that should be considered
a "set", i.e. from the same instrument. This would allowing explicit grouping of BHE, BHN & BHZ and other
combinations like BH1, BH2 & BHZ.

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