Dear Salim, I don't know SS1 seismometers, can you tell us a little more about those ? Corner frequency? Instrument response? About the filters, well, this is strongly dependent on the target of the study, and of the number of station & their spacing... Please provide lots of details, I'm sure people on this mailing list can also help ! Cheers, Thomas On 31/10/2018 14:35, guettouche, salim wrote: -- Dr. Thomas Lecocq Geologist - Seismologist Seismology - Gravimetry Royal Observatory of Belgium * * * * * * * * * * --------- http://www.seismology.be http://msnoise.org http://twitter.com/#!/Seismologie_be https://www.facebook.com/seismologie.be