1. Station Metadata: What do I Need?
Dr. Mary Templeton
IRIS Data Management Center
Managing Data from Seismic Networks
August 20-26, 2017
Pretoria, South Africa

2. Why is Metadata Important?
To use data, you need to know where and how it was recorded:
x,y,z,t
How do you translate the time series to ground motion?
Direction of motion recorded
Amplitude scaling
Phase shifting
The data format must be understood
Metadata is easiest to record before it’s forgotten

3. Steps for Building Metadata
Register your network and station names
Networks:
You now have the ability to provide or request the FDSN creates a Digital Object Identifier (DOI) for you network
Stations:
Create a dataless SEED volume
Enter network information
Enter information for a single station
Optional: Add additional stations using the first as a “clone”

4. What do I Need? Example: II.SUR.00.BH{12Z}
Network information
FDSN network code (network ID)
Operating institution (network operator)
Blue terms are those used by PDCC Build A Station

5. What do I Need? Station information
Registered station code (station name)
Station long name (site description)
Location of the station and it’s sensors
Latitude (degrees from -90 to +90)
Longitude (degrees from -180 to +180)
Elevation (ground surface and sensor in m)
Depth (surface elevation – sensor elevation in m)

6. What do I Need? Station information Sensor wiring convention
Normal: upward ground motion produces a positive Z amplitude; Z dip is -90 (most earthquake sensors)
Reverse: upward ground motion produces a negative Z amplitude; Z dip is +90 (industry geophones)
Sensor channel orientations
Angle from magnetic north to each horizontal channel (azimuth in degrees from 0 to 360)

7. What do I Need? Station information Sample rate20
Sensor long-period corner
360 s (STS-1)
Sensor gain
2400 V/m/s (STS-1 nominal gain)
No corner period needed for accelerometers

8. What do I Need? B,H,C,F S,E,D,G H L
BH? (40 sps)
SH? (40 sps)
SL? (40 sps)
Is the nominal sensor gain larger or smaller than 200 V/m/s?
How channel naming depends on sensor corner frequency and gain

9. What do I Need? Station information Instrument response Sensor
Sensitivity
Poles and zeros
A0 normalization factor
Datalogger
Preamplifier gain
Bit weight (A/D scale factor)
FIR coefficients for your field acquisition settings
other
Other – information about other acquisition settings that affect response (e.g. optional filters)

10. OR If your instruments are in the Nominal Response Library… http://ds
NRL has a web version and is available to PDCC
Selecting correct response depends on knowing the characteristics and acquisition parameters for your instrumentation

11. …you will need Station information Instrument response Sensor
Manufacturer
Model
Other
Other – sometimes corner period, sensitivity, component

12. …you will need Station information Instrument response Datalogger
Manufacturer
Model
Preamplifier gain
Sample rate
Other
Other – linear vs. nonlinear FIR filters, software gain settings, optional IIR filters…

13. What do I Need? Station information Optional
Text description of instrumentation
Instrument serial numbers
Comments documenting timing and other data problems

14. What do I Need? And Finally….
Time span (epoch) for which this information is valid (YYYY,JJJ,HH:MM:SS.ffff)
If any of this metadata changes, a new epoch needs to be created with updated metadata
Epochs must not overlap in time - you must close the previous epoch (edit the end time) whenever you add a new epoch for the same channel.

15. After the Break…
…we’ll use metadata for GSN station II.SUR (Sutherland, South Africa) to learn how to create a Dataless SEED volume using the program PDCC.