Raw waveform data and basic station information are available from the KNMI network.
The RRSM database is populated via a strong motion processing module "scwfparam" which is integrated in SeisComP3 (SC3).
The RRSM "scwfparam" processing is triggered after an earthquake is published by the KNMI.
Earthquake data is being processed if it meets the following criteria:
- Magnitude (any scale) ≥ 2.0
Note: After the data gathering and filtering are done, only the stations that exceed certain STA/LTA threshold are further processed. This can result in situations where events which its magnitude is bigger or equal than 2.0 does not appear in this interface, because any station has been finally processed.
Waveform data are collected from accelerometer stations of the Groningen's network within 150km maximum epicentral distance. The length of the requested time windows is 60 seconds. The corner frequencies of the filter depend on the magnitude:
||0.5 Hz – 80% Nyquist
||0.3 Hz – 80% Nyquist
||0.1 Hz – 80% Nyquist
||0.05 Hz – 80% Nyquist
In addition, a post-deconvolution filter (0.05 Hz – 40Hz, order 4) is applied in the frequency domain to get rid of noise blown up by the process as well as possible distortions in the original signal.
Each earthquake is reprocessed after some time to ensure all available data to be included. Current scheduling is:
- Immediately upon receiving alert
- 10 minutes after origin time
The database is filled with data since 2013.