sean@........... wrote: > > > The abstract explains the principle of its operation. Since the VBB-BBT > is insensitive to horizontal acceleration, which a horizontal seis > senses, its output will only be the tilt noise of the pier environment, > which a horizontal seis is also sensitive to, especially at long periods. > So with identical tilt sensitivities, the signal from the VBB-BBT can > be subtracted from that of the broadband horizontal seis, leaving only > the true seismic signal of interest. The VBB-BBT signal must be digitized > and processed identically to the broadband seismic signal. I maybe presumptive on this, but it sounds like a seismic station would likely need two of the VBB-BB's, one for each direction orientation of a "companion" normal BB horizontal seismometer? This leads up to the question of whether your tiltmeter is indeed direction sensitive which I presume it is? This sounds like a very good "noise filter" which would give a much clearer seismic picture with alot of better implications for professional installations and researchers. No wonder Dr. Hutt with USGS wanted you to pursue it with vigor! > > > Regards, > Sean-Thomas > > I will review the info on the bought magnet and the coil construction > and post it tomorrow. I also have a box flexure design for the BBT that > I also used to make a compact (10" long) horizontal broadband seis as a > companion to a compact version of the the leaf spring vertical. That should be very interesting also; its always nice to read of leading edge material that inspires advancements; as you are the only real instrumentation authority (teacher)that PSN benefits from. Thanks, Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>