next up previous contents index
Next: 27.0.1 Input Up: SEISAN Previous: 26.1 Moment Tensor inversion   Contents   Index

27. Calculation of coda q, CODAQ

This section contains the main program CODAQ to calculate coda Q, program CODAQ_AREA to sort output from CODAQ into areal bins and a help program AVQ to average Q-relations.

Codaq

The program will calculate coda Q (hereafter called Q) for a series of events and stations at given frequencies. On completion, the average values are calculated and a Q vs f curve is fitted to the calculated values. The program will also plot the individual events and filtered coda windows.

The principle for calculation is the standard coda Q method, whereby a coda window is bandpass filtered, an envelope fitted and the coda Q at the corresponding frequency calculated. The envelope is calculated RMS value of the filtered signal using a 5 cycle window. The program used here is the one described in Havskov et al. [1989]. The program can only operate in connection with the SEISAN format S-files. The program can use all waveform file types accepted by SEISAN and there can be more than one waveform file in the S-file. The program will also take advantage of the SEISAN database structure.



Subsections
next up previous contents index
Next: 27.0.1 Input Up: SEISAN Previous: 26.1 Moment Tensor inversion   Contents   Index
Peter Voss : Mon Feb 27 10:16:12 UTC 2017