Glossary

100x rule

According to the Ringler’s recommendations, if you want to resolve a frequency, you have to robustly average ~100 coefficients for that frequency which are independent, that is, coming from different time windows.

Also: “A rule of thumb is that the required sample duration should be 100 times the longest period needed to be measured.” For SPs that is 2 seconds or a few minutes. For LPs that might be 1000s or a little over one day. SRC: http://www.earthmode.org/procedure.htm (from http://www.earthmode.org/)

FDSN

International Federation of Digital Seismograph Networks Resources:

• http://www.fdsn.org/

FFT

Fast Fourier Transform

miniSEED

miniSEED is the subset of the SEED standard that is used for time series data. Resources:

• http://www.iris.edu/dms/nodes/dmc/data/formats/
• http://www.fdsn.org/seed_manual/SEEDManual_V2.4.pdf

Pavlis method

After Pavlis and Vernon (1994). See Recommended background reading

PZs

Poles and zeros

RESP

A RESP-formatted text file contains instrument response values including poles, zeros and gain. Resources:

• http://ds.iris.edu/ds/nodes/dmc/kb/questions/60/what-is-a-resp-file/
• https://ds.iris.edu/ds/nodes/dmc/kb/questions/99/what-are-the-fields-in-a-resp-file/
• http://www.fdsn.org/seed_manual/SEEDManual_V2.4.pdf

restore

Restore means the following:

For each frequency:

• Build 1-D arrays of spectra coefficients for the unknown input and the known input; elements correspond to that particular frequency, but to different time windows;
• Elementwise, divide the first array by the second; and
• Robustly average the resulting array over all the the time windows to get the transfer function coefficient.

robustly average

A statistical method of parameter estimation which does not favor outliers. Best described here: Chave and Thomson (1989). Also available here: http://www.researchgate.net/publication/228077447_Some_Comments_on_Magnetotelluric_Response_Function_Estimation/file/9c9605249d44b5b7a9.pdf