Recent content by Squatchmichae

Hi Dave, I never claimed p-waves (a type of body wave) travels slower than shear or surface waves. I simply stated that higher frequency body waves can travel faster slower than their lower frequency counter-parts. So, a 100Hz p-wave may arrive at a seismometer later than 0.1 Hz p-wave...

Careful regarding the comment that high-frequency body waves travel faster--while there are pathological examples in which body waves do travel faster when they have higher frequency, longer-wavelength signals often arrive at receivers first. This is because these longer wavelengths sample...

Question for the community: Is there a resource online for acquiring NASA Orion launch data? More specifically, does NASA provide the nadir-point (by which I mean, the point on the Earth nearest to the craft) data with time? It seems like a great data set.

This appears to be a slightly old thread, but I will respond: Using a single three-component seismometer, it is possible to crudely estimate the location of an earthquake if a p-wave and s-wave are clearly recorded. By computing the polarization vector of the incoming p-wave from the...

Hi Marcusl, Thanks for the response. To answer your last question, my question is associated with research--I would like to ensure that I am getting a good estimate of noise of my seismic data, but I don't want to have to pre-filter microseismic events out first. That would require making a...

This question concerns estimating the PDF of noise, based upon observations of a data stream consisting of noise embedded with transient signals. I would like to know if my Proposed Solution is a correct approach. Suppose I have "long" stream of seismic data, consisting of noise, and with...

I would recommend thinking of cross-correlation as an application of using inner product spaces. If that sounds a little advanced, no worries--it's not as scary as it sounds. You can think of cross-correlation in terms of probability estimates (coherence and maximum likelihood) or in terms of...

Just to be clear (sorry to answer with a question), are you attempting to change the (1) amplitude of the signal (2) the frequency content of the signal or (3) add a signal to the accelerometer plate such that is not so over-estimated? It sounds as though you want to do (3). I am unclear as to...

I found a claim in a paper (BSSA, Vol 81, No. 6: "A Waveform Correlation Method for Identifying Quarry Explosions", By D.B. Harris) concerning finding filter coefficients. The statement is given without proof. I cannot locate a reference or theorem for the following, and have not been able thus...

I understand the confusion--that is what makes the defining characteristic a little awkward. The basic idea is this: each element in the convex set \textit{C} must correlate with every other element above \rho. But we also know that a given (known) element \textbf{w}(t) is contained in...

I am trying to ultimately find the projector onto a convex set defined in a non-explicit way, for a seismic processing application. The signals in question are members of some Hilbert Space H and the set membership requires that they must correlate with each other above some scalar \rho, given...

Here is a esoteric problem that is totally unique in nature: Taylor Glacier, in the Dry Valleys of Antarctica, hosts site of a Fe2+ brine solution, expressed as a rusty discharge at the terminus. There is strong diurnal signals in seismic data gathered from an array co-located there, not...