Date: Tue, 30 Jul 2002 08:16:39 -0600 From: "Jonathan M. Hanson" <jhanson@..............> Subject: Re: WinSDR update
Hi Larry -
I know the feeling regarding lack of time. It would probably be a
reasonable thing to check out this method first before modifying
WinQuake. In principle, it should work and indeed is discussed in the
literature. It is certainly easy to implement. If you happen to have
some code lying around that will convert a PSN format (as recorded by
WinSDR) to amplitude vs time in ascii, I can write a little routine
that will import a user-defined time window of the ascii data and simply
plot up the particle motion to check it out. This would save me the time
and effort of writing a conversion code from scratch. An executable to
do this conversion on a PC would be ideal I have a number of examples
of local quakes to compare the results to.
Regards, Jon
Larry Cochrane wrote:
> Thanks Jon. Please send any info you can on how to do this.
> Unfortunately I don't have time right now to work on any new features
> in WinQuake. Hopefully in a few weeks I can work on adding this feature.
>
>
>
> Regards,
>
> Larry
>
> ----- Original Message -----
>
> From: Jonathan M. Hanson <mailto:jhanson@..............>
>
> To: winsdr@.............. <mailto:winsdr@..............>
>
> Sent: Monday, July 29, 2002 9:46 AM
>
> Subject: Re: WinSDR update
>
>
> Larry -
>
> I just got off the phone with Lew Katz (Utah Geophysical). It
> would appear that the simplest way to estimate direction to the
> quake is by simply plotting particle motion. For example, specify
> a time window that contains the P wave. Then plot the EW component
> on the X axis and the NS component on the Y axis. This will give a
> crude estimate of direction to (or from) the quake. Looking at the
> first motions would eliminate the reduncy in solution. If velocity
> sensors are used, I presume that one would want to integrate the
> data before plotting. Also, it probably would be useful to apply
> this method to either filtered or unfiltered data just to have a
> bit more control. An identical approach could be used for other
> phases but, depending on the particle motion with respect to the
> line-of-site to the quake, interpretation would be different.
> Also, one could include the Z coordinate but this might be
> difficult to interpret unless you put up a 3D box frame on the
> screen with slider bars so that you could rotate the box (with
> particle tracks plotted inside the box) in 3D. There are much more
> sophisticated methods (see for example the Users Manual for PITSA
> by Scherbaum and Johnson, IASPEI Software Library Vol 5, p. 119)
> but the simple method outlined here would be easy to implement.
>
> I can delve into this further if you need additional references, etc.
>
> Regards, Jon
>
> Larry Cochrane wrote:
>
>>Hi Jonathan,
>>
>>Thanks for the update. On the WinQuake wish list is the ability to plot the
>>direction based on three components. The problem is I don't know how to do
>>this so I need to do some research before I can add this feature.
>>
>>Regards,
>>Larry Cochrane
>>Redwood City, PSN
>>
>>----- Original Message -----
>>From: "Jonathan M. Hanson" <jhanson@..............>
>>To: <winsdr@..............>
>>Sent: Sunday, July 28, 2002 8:07 AM
>>Subject: WinSDR update
>>
>>
>>>Hi Larry -
>>>
>>>Thanks for the WinSDR update. I have not contacted you since I got my
>>>system going so here is a brief update.
>>>
>>>A friend of mine (Lew Katz, Pres. Utah Geophysical) has lent me several
>>>geophones to play around with. The most intriguing is an Electro-Tech
>>>EV-17H that he dug out of one of his storage units. I have not been
>>>able to find any information on this unit but it seems to have a
>>>somewhat lower frequency response than the Mark Products geophone I
>>>purchased from you. I have attached a couple of jpegs showing recorded
>>>quakes about 60 miles (Huntsville, UT) and a couple of hundred miles
>>>(Yucca Mtn, NV) as recorded by this unit on June 2 of this year. The
>>>picture labeled june14_02 shows both quakes..the first is the Huntsville
>>>quake and the second is the Yucca Mtn quake. The picture labeled
>>>june15_02C shows the Huntsville quake. I would appreciate any
>>>information you might have on the EV-17H. I di
>>>d a web search and the
>>>only hit I got on Electro-Tech was one geophone on the SEG "virtual
>>>museum" site. I suspect my unit was built in the 40's or 50's but this
>>>is pure speculation. I have not yet had the time to build a long-period
>>>sensor but hope to do so shortly.
>>>
>>>Do you have any short or long term plans of adding some sort of
>>>polarization filter module to WinQuake? This might allow those users
>>>that are recording 3 components to get an estimate not only of the
>>>distance to the quake but also direction. There is a rather large amount
>>>of mining activity in Utah and surrounding states. A directional filter
>>>would help me sort out the mining-associated activity from other activity.
>>>
>>>Best regards,
>>>
>>>Jonathan Hanson
>>>
>>
>>
>>
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