Subject: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Sun, 30 Sep 2001 18:25:21 -0230
Late one recent night I realized that building a seismic detector
for my location may be a waste of time.
The airport is realitively close to the town, and that night the
departing aircraft were flying over the town. Some of the larger
aircraft rattle the windows, and shake the house. Is this type of
vibration likely to be detected on a seismograph?
Ron (in Gander, Newfoundland)
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Public Seismic Network Mailing List (PSN-L)
Subject: Re: noise from aircraft question
From: CapAAVSO@.......
Date: Sun, 30 Sep 2001 19:41:00 EDT
In a message dated 9/30/01 9:52:05 PM GMT Daylight Time,
rlthompson@................. writes:
<< The airport is realitively close to the town, and that night the
departing aircraft were flying over the town. Some of the larger
aircraft rattle the windows, and shake the house. Is this type of
vibration likely to be detected on a seismograph? >>
Hi Ron,
My experience living under planes taking off from busy Orlando, FL airport is
it won't make a bit of difference. During the winter I live in Orlando and
operate a vertical leaf spring seismometer with a 1 Hz low pass filter. Very
little if any cultural noise got through the filter at another location about
40 m from a busy highway with many big trucks. There I could see the highway
noise on an oscilloscope before the filter but none of it got through the 1
Hz low pass filter.
Good luck,
Cap
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Public Seismic Network Mailing List (PSN-L)
Subject: Re: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Sun, 30 Sep 2001 21:51:32 -0230
Thanks,
When I get time again, (not likely to happen till spring), I'll see about
getting back to building a detector. We get some rather large aircraft at times,
C5's, and Antonov 124's.
Ron
CapAAVSO@....... wrote:
> In a message dated 9/30/01 9:52:05 PM GMT Daylight Time,
> rlthompson@................. writes:
>
> << The airport is realitively close to the town, and that night the
> departing aircraft were flying over the town. Some of the larger
> aircraft rattle the windows, and shake the house. Is this type of
> vibration likely to be detected on a seismograph? >>
>
> Hi Ron,
>
> My experience living under planes taking off from busy Orlando, FL airport is
> it won't make a bit of difference. During the winter I live in Orlando and
> operate a vertical leaf spring seismometer with a 1 Hz low pass filter. Very
> little if any cultural noise got through the filter at another location about
> 40 m from a busy highway with many big trucks. There I could see the highway
> noise on an oscilloscope before the filter but none of it got through the 1
> Hz low pass filter.
>
> Good luck,
> Cap
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
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> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
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Subject: Re: noise from aircraft question
From: ChrisAtUpw@.......
Date: Sun, 30 Sep 2001 21:15:37 EDT
In a message dated 30/09/01, rlthompson@................. writes:
> Late one recent night I realized that building a seismic detector for my
> location may be a waste of time.
> The airport is realitively close to the town, and that night the
> departing aircraft were flying over the town. Some of the larger aircraft
> rattle the windows, and shake the house. Is this type of vibration likely
> to be detected on a seismograph?
Depends a bit where you put your seismometer and what frequencies /
periods you use. Environmental noise tends to be bad from maybe 20 Hz up, but
this should have been filtered out anyway.
The top cut seis filter is maybe 10 Hz for quieter locations, or 3 Hz
for noisier ones. You get the ocean background between 1 and 10 seconds,
maybe peaking in the 6 second region, so if you are looking at 3 Hz down to 1
Hz or below 0.1 Hz, you will probably be OK.
You must not expect the earth to be 'quiet' anyway. Sorting out which
signal is due to which cause is all part of the fun. I have a gale blowing
here at the moment and the background noise is way up. Can't even pick out
the traffic from the main road about 100 yards away, which more usually gives
me problems! With viewing programmes like Winquake, you can do digital
filtering and remove a lot of noise after it has been recorded. The results
can be quite spectacular.
Have you made any progress with the sensor electronics that you were
going to try out, yet? Do keep us informed!
Regards,
Chris Chapman
In a message dated 30/09/01, rlthompson@................. writes:
Ron
Have you made any progress with the sensor electronics that you were going
to try out, yet? Do keep us informed!
Regards,
Chris Chapman
 
; Late one recent night I realized that building a seismic detector for my location may be a waste of time.
The airport is realitively close to the town, and that night the departing aircraft were flying over the
town. Some of the larger aircraft rattle the windows, and shake the house. Is this type of vibration likely to be detected on
a seismograph?
Depends a bit where you put your seismometer and what frequencies / periods you use. E
nvironmental noise tends to be bad from maybe 20 Hz up, but this should have been filtered out anyway.
The top cut seis filter is maybe 10 Hz for quieter locations, or 3 Hz for noisier ones
. You get the ocean background between 1 and 10 seconds, maybe peaking in the 6 second region, so if you are looking at 3 Hz do
wn to 1 Hz or below 0.1 Hz, you will probably be OK.
You must not expect the earth to be 'quiet' anyway. Sorting out which signal is due to
which cause is all part of the fun. I have a gale blowing here at the moment and the background noise is way up. Can't even pi
ck out the traffic from the main road about 100 yards away, which more usually gives me problems! With viewing programmes like
Winquake, you can do digital filtering and remove a lot of noise after it has been recorded. The results can be quite spectacul
ar.
Have you made any progress with the sensor electronics that you were going to try out,
yet? Do keep us informed!
Regards,
Chris Chapman
Subject: Re: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Mon, 01 Oct 2001 07:24:50 -0230
> No progress yet, but its not due to a lack of interest. I think
> that I'll start with the mechanical components first, then if the
> detector itself doesn't work out I can use a more tried and proven
> design.
As I'm well inland here I don't expect to have much noise from the
sea. But it does get windy and I have trees on the property and a
wooden power line pole near where I hoped to install the detector (on
the concrete floor of a storage shed).
Ron
>
>
> Have you made any progress with the sensor electronics that you
> were going to try out, yet? Do keep us informed!
>
> Regards,
>
> Chris Chapman
No progress yet, but its not due to a lack of interest. I think that
I'll start with the mechanical components first, then if the detector itself
doesn't work out I can use a more tried and proven design.
As I'm well inland here I don't expect to have
much noise from the sea. But it does get windy and I have trees on
the property and a wooden power line pole near where I hoped to install
the detector (on the concrete floor of a storage shed).
Subject: Manuf. Production/Contrl Software For $1,495.00!
From: jbsptrsft55@.........
Date: Tue, 02 Oct 2001 09:00:55 +0100
(ES102)Job Master, a complete, user friendly Windows based software
package, can manage and control your operation from sales quote to
shipment.
For one week only, Job Master, normally $2,495.00, is on sale for a
total price of $1,495.00. In order for you to receive this $1,000.00
savings we must have your order by October 10.
(To reply by E Mail to this message or be removed from our list, Please
go to the bottom of this message for an E Mail link.)
Job Master is designed specifically for small to medium sized
manufacturers, and costs many thousands of dollars less than any other
even remotely comparable software package.
Following is a list of features. If you have any questions, would like
to discuss the package further, or if you would like to obtain our Web
site address for a total walk through of the program, please call me
directly at (661) 254-9926.
By way of background, we are a software company, which for some years
has specialized in the development of custom software, primarily for
small to medium sized manufacturers. Job Master is a distillation of
over a million and a half dollars of software we have developed to
control and manage the production of our manufacturing clients.
Job Master contains the following features:
1. QUOTATION MODULE. In this module, quotes are developed, modified,
and produced for sending to your client. A history is kept of all
quotes for future reference, or modification for other clients. All
quotations and revisions are "auto numbered," including versions. The
quotes section allows for the entry of parts/processes, and costing of
each, including materials, labor, markup, and taxes. Inventory status
can be accessed from this section for reference.
2. SALES ORDER. Once a quotation is accepted, the final quotation
information can be transformed into a Sales Order for your client's
signature on a "point and click" basis. The Sales Order can be
modified and re issued if necessary. A history if kept of all Sales
Orders for future reference, or modification for other clients. All
sales orders and revisions are "auto numbered," including versions.
Inventory status can be accessed from this section for reference.
3. CUSTOMER LETTERS can be created from the Quotation and Sales Order
sections.
4. SHOP TRAVELER/WORK ORDER. Once a Sales Order is accepted, the sales
order information can be transformed into a shop traveler/work order on
a "point and click" basis. Each item on the Sales Order becomes a shop
traveler/work order, with each step of production of the item then
listed on the traveler/work order. Each such traveler/work order is
tied back into the Sales Order. The shop traveler/work order allows
for the entry of line items, and notes on each line item. The shop
traveler/work order contains a "notes" section. The Shop traveler/work
order allows for the storing or attachment of drawings to the
traveler/work order. The shop traveler/work order also contains a
"drop down," from which standard processes can be selected for
inclusion on the shop traveler/work order. The shop traveler/work
order numbers progress in order of production sequence, and re numbers
them if new steps are added. The shop traveler/work order allows for
change orders or revisions, and numbers changes in sequence of the
original shop traveler/work order number; i.e., 100, 100-1, 100-2, etc.
All shop traveler/work orders and related revisions are retained in
memory for future reference. The shop traveler/work order is bar coded
for tracking of production step by step, and production of ongoing
client status reports. Bar coding includes the ability for an employee
to "swipe" their own ID bar code for recording in the system as to who
upgraded what step. The shop traveler/work order function also allows
for manual update of production status. The shop traveler/work order
allows for quality control sign off, and the final production of
certifications, either from a "canned" list, or hand typed in on a case
by case basis.
5. INVENTORY. The application includes an inventory section, which
allows operations to check materials inventory in and out. The
inventory section allows for the comparison of inventory received
against a P.O., and produces an "overage/underage" report of inventory
received as compared against the P.O. The inventory section allows for
the setting of minimum (re-order now!) and maximum inventory amounts,
and produces reports showing what inventory needs to be ordered, as
well as inventory that is at or above the maximum set to have in house.
The inventory section also tracks "partially shipped" orders, which are
tied in to the shipping function. This section shows how much
completed product under a particular order has been actually shipped to
a client, and how much remains to be shipped. The balance is adjusted
as shipments are made.
6. REQUEST FOR PURCHASE. The application allows operators to produce a
Request For Purchase for accounting for any inventory items, which need
to be ordered. Inventory items have a drop down of approved vendors
for each item.
7. REQUEST FOR BID. The application allows operators to produce a
Request For Bid for accounting to send to Vendors for any inventory
items, which need to be ordered. Inventory items have a drop down of
approved vendors for each item to which Requests For Bid can be sent.
8. INVOICE. The application produces an invoice/invoice detail for all
completed items ready to be billed/shipped to clients.
9. PRODUCTION OUTPUT STATUS. The application produces a date range
selectable report on how much product, and the value of the product,
which was completed during a selected date range. The application also
produces a report on how many orders, and the value of those orders,
which remain to be completed during a selected date range.
10. The application produces SHIPPING DOCUMENTS as per selected
shippers, and produces a PACKING SLIP.
11. The application has a "FIND" FUNCTION in selected sections,
allowing for searches by customer name, work order number, etc.
12. The application has "AUTO FILL;" i.e., when an operator starts to
type in a name, number, etc. all related information auto fills after
the first few letters or numbers are typed in.
Job Master is currently being sold in the marketplace for $2,495.00 per
package. However, if we receive your order by October 10.
Again, if you have any questions at all, or would like to place your
order, please call me on my direct line, (661) 254-9926. Thank you!
Mario Chavez
Vice President of Sales and Marketing
Link It Software Corp.
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Per Section 301, Paragraph (a)(2)(C) of S. 1618.
To REPLY or be REMOVED from this solicitated email list, please click
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Subject: REMOVE
From: peaches@............ (Donna Whitaker)
Date: Tue, 2 Oct 2001 06:27:27 -1000 (HST)
REMOVE
>
>(ES102)Job Master, a complete, user friendly Windows based software
>package, can manage and control your operation from sales quote to
>shipment.
>
>For one week only, Job Master, normally $2,495.00, is on sale for a
>total price of $1,495.00. In order for you to receive this $1,000.00
>savings we must have your order by October 10.
>
>(To reply by E Mail to this message or be removed from our list, Please
>go to the bottom of this message for an E Mail link.)
>
>Job Master is designed specifically for small to medium sized
>manufacturers, and costs many thousands of dollars less than any other
>even remotely comparable software package.
>
>Following is a list of features. If you have any questions, would like
>to discuss the package further, or if you would like to obtain our Web
>site address for a total walk through of the program, please call me
>directly at (661) 254-9926.
>
>By way of background, we are a software company, which for some years
>has specialized in the development of custom software, primarily for
>small to medium sized manufacturers. Job Master is a distillation of
>over a million and a half dollars of software we have developed to
>control and manage the production of our manufacturing clients.
>
>Job Master contains the following features:
>
>1. QUOTATION MODULE. In this module, quotes are developed, modified,
>and produced for sending to your client. A history is kept of all
>quotes for future reference, or modification for other clients. All
>quotations and revisions are "auto numbered," including versions. The
>quotes section allows for the entry of parts/processes, and costing of
>each, including materials, labor, markup, and taxes. Inventory status
>can be accessed from this section for reference.
>
>2. SALES ORDER. Once a quotation is accepted, the final quotation
>information can be transformed into a Sales Order for your client's
>signature on a "point and click" basis. The Sales Order can be
>modified and re issued if necessary. A history if kept of all Sales
>Orders for future reference, or modification for other clients. All
>sales orders and revisions are "auto numbered," including versions.
>Inventory status can be accessed from this section for reference.
>
>3. CUSTOMER LETTERS can be created from the Quotation and Sales Order
>sections.
>
>4. SHOP TRAVELER/WORK ORDER. Once a Sales Order is accepted, the sales
>order information can be transformed into a shop traveler/work order on
>a "point and click" basis. Each item on the Sales Order becomes a shop
>traveler/work order, with each step of production of the item then
>listed on the traveler/work order. Each such traveler/work order is
>tied back into the Sales Order. The shop traveler/work order allows
>for the entry of line items, and notes on each line item. The shop
>traveler/work order contains a "notes" section. The Shop traveler/work
>order allows for the storing or attachment of drawings to the
>traveler/work order. The shop traveler/work order also contains a
>"drop down," from which standard processes can be selected for
>inclusion on the shop traveler/work order. The shop traveler/work
>order numbers progress in order of production sequence, and re numbers
>them if new steps are added. The shop traveler/work order allows for
>change orders or revisions, and numbers changes in sequence of the
>original shop traveler/work order number; i.e., 100, 100-1, 100-2, etc.
>All shop traveler/work orders and related revisions are retained in
>memory for future reference. The shop traveler/work order is bar coded
>for tracking of production step by step, and production of ongoing
>client status reports. Bar coding includes the ability for an employee
>to "swipe" their own ID bar code for recording in the system as to who
>upgraded what step. The shop traveler/work order function also allows
>for manual update of production status. The shop traveler/work order
>allows for quality control sign off, and the final production of
>certifications, either from a "canned" list, or hand typed in on a case
>by case basis.
>
>5. INVENTORY. The application includes an inventory section, which
>allows operations to check materials inventory in and out. The
>inventory section allows for the comparison of inventory received
>against a P.O., and produces an "overage/underage" report of inventory
>received as compared against the P.O. The inventory section allows for
>the setting of minimum (re-order now!) and maximum inventory amounts,
>and produces reports showing what inventory needs to be ordered, as
>well as inventory that is at or above the maximum set to have in house.
>The inventory section also tracks "partially shipped" orders, which are
>tied in to the shipping function. This section shows how much
>completed product under a particular order has been actually shipped to
>a client, and how much remains to be shipped. The balance is adjusted
>as shipments are made.
>
>6. REQUEST FOR PURCHASE. The application allows operators to produce a
>Request For Purchase for accounting for any inventory items, which need
>to be ordered. Inventory items have a drop down of approved vendors
>for each item.
>
>7. REQUEST FOR BID. The application allows operators to produce a
>Request For Bid for accounting to send to Vendors for any inventory
>items, which need to be ordered. Inventory items have a drop down of
>approved vendors for each item to which Requests For Bid can be sent.
>
>8. INVOICE. The application produces an invoice/invoice detail for all
>completed items ready to be billed/shipped to clients.
>
>9. PRODUCTION OUTPUT STATUS. The application produces a date range
>selectable report on how much product, and the value of the product,
>which was completed during a selected date range. The application also
>produces a report on how many orders, and the value of those orders,
>which remain to be completed during a selected date range.
>
>10. The application produces SHIPPING DOCUMENTS as per selected
>shippers, and produces a PACKING SLIP.
>
>11. The application has a "FIND" FUNCTION in selected sections,
>allowing for searches by customer name, work order number, etc.
>
>12. The application has "AUTO FILL;" i.e., when an operator starts to
>type in a name, number, etc. all related information auto fills after
>the first few letters or numbers are typed in.
>
>Job Master is currently being sold in the marketplace for $2,495.00 per
>package. However, if we receive your order by October 10.
>
>Again, if you have any questions at all, or would like to place your
>order, please call me on my direct line, (661) 254-9926. Thank you!
>
>
>Mario Chavez
>Vice President of Sales and Marketing
>Link It Software Corp.
>
>
>
>-----------------------------------------------------------------------
>-------------------
>
>
>This message is sent in compliance of the new e-mail bill: SECTION 301.
>Per Section 301, Paragraph (a)(2)(C) of S. 1618.
>
>To REPLY or be REMOVED from this solicitated email list, please click
>on the E Mail address following this message and type "REMOVE" or
>"REPLY" in the subject line: jbsptrsft55@.........
>-----------------------------------------------------------------------
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>
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>unsubscribe psn-l (first line only). You will also need to email:
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>unsubscribe
>
>
>
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unsubscribe
Subject: What type of foundation is needed
From: "Jan D. Marshall" jandmarshall@............
Date: Tue, 2 Oct 2001 12:12:37 -0600
I am starting to design my sensors and electronics and have decided that =
I understand the requirments there pretty well -- what I don't have a =
very good understanding on is what do I need for a base or foundation to =
set the sensors on. What type of mass does it need? does it need to set =
on bed rock? I do not have any cement slab floors.
Thanks
Jan D. Marshall
Nampa, Idaho
jandmarshall@............
Subject: FW: Stephenson Probe - website upgrade
From: steve hammond shammon1@.............
Date: Wed, 3 Oct 2001 15:01:18 -0700
I received this from Bill Stephenson and thought I would pass it on to the group.
Regards, Steve Hammond
Subject: Stephenson Probe - website upgrade
Hi,
This is just to alert you to the fact that new information has been put on the
website describing the probe.
Cheers,
Bill
--
Bill Stephenson, Seismology Section,
Hazards Group, Institute of Geological & Nuclear Sciences,
P.O. Box 30368, Lower Hutt, New Zealand
Phone: +64 4 570 1444 Direct: +64 4 570 4757 Fax: +64 4 570 1440
B.Stephenson@..........
The Stephenson Probe: http://www.gns.cri.nz/earthact/probe
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Stephenson Probe - website upgrade
From: "valhutch" valhutch@.........
Date: Wed, 3 Oct 2001 17:34:28 -0600
Please erase me from your lists of emails.
valhutch@.........
-----Original Message-----
From: steve hammond
Perhaps.....the most important aspect is,....what kind of
terrain and/or space do you have available....i.e, city/country,
to place any seismo on. Any house crawlspace available, or
garage, shed, or least disturbed area of land around? One
will have to make "do" with what they have for placement.
If you do indeed have bedrock, that would be a plus....if...its
convenient and adaptable for a seismic "vault". If you have
loose soil, the best remote and least watered/susceptible
area would be best.
The best material seems to be a "pier" of concrete, that can
be inside/outside weather enclosed and somewhat isolated from
domestic seismic sources of "noise"......or....if not possible
to do so, one would have to live with the noise it generates;
which is usually easy to denote with time/experience. The
pier usually needs to "fit" the area required by the sensor/s
anticipated. The thickness of the concrete slab can be
debated I suppose, but I'd try for whatever depth/thickness
you can squeeze in the spot you chose. I use about a 7-8"
thickness of my three piers....which are in reality cast concrete
pavers stacked together but layered in the joints and surfaces
with real concrete. I chose this as it was near impossible to
mix massive concrete on my knees under the house, let alone
move all the sand/concrete therein. For myself, I elected to
also use thick mylar sheet under the piers, to limit water
absorbion into the piers. I even used a water repellent paint
on the pier/s to limit water absorbtion. Even after completion,
you can expect a period of time before the piers stabilize from
curing....perhaps acouple months. If you can make the pier
thickness even greater than say...6 inches thick, I'd do so.
Do
not use iron, steel in the pier.
Personally I live in Denver, and in a city lot.....so, I use my
house soil crawlspace for pier/seismometer placements. I
also enclosed the piers with walls and insulation to somewhat
limit temperature excursion that do occur. Among the PSN
members....we kind of all utilize whats available.....
So....in a way....everything gets back to what space you
have now that could be utilized. Next, the physical size of
your anticipated seismos you're planning on building/using.
I think you're right to get into the seismo housing/piers aspect
right off the bat.....if one doesn't; than they will get into alot
of
soil tilt, water, weather, temperature related problems that
will
make any consistent seismic monitoring rather useless otherwise.
Suggest that any pier/containment is well built and temperature
insulated; this can take time, but it would pay off in the long
run.
Outside of the above,.....what kind of seismic sensors are you
planning on using.....the instrumentation sensor aspect is always
interesting.
Take care, Meredith Lamb
"Jan D. Marshall" wrote:
I am starting to design my sensors and electronics and have decided that I understand the requirments there pretty well -- what I don't have a very good understanding on is what do I need for a base or foundation to set the sensors on. What type of mass does it need? does it need to set on bedrock? I do not have any cement slab floors. Thanks Jan D. Marshall
Nampa, Idaho
jandmarshall@............Subject: Re: What type of foundation From: "Jan D. Marshall" jandmarshall@............ Date: Fri, 5 Oct 2001 18:12:07 -0600 My first attempt is going to be a Lehman. I am not afraid to tackle = anything however. As soon as I get an amp, filter, A/D converter and = the PC software going I thing it is going to be fun expermiting with = different sensors. Jan D. Marshall Nampa, Idaho jandmarshall@............ ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Friday, October 05, 2001 12:41 AM Subject: Re: What type of foundation Hi Jan,=20 Perhaps.....the most important aspect is,....what kind of=20 terrain and/or space do you have available....i.e, city/country,=20 to place any seismo on. Any house crawlspace available, or=20 garage, shed, or least disturbed area of land around? One=20 will have to make "do" with what they have for placement.=20 If you do indeed have bedrock, that would be a plus....if...its=20 convenient and adaptable for a seismic "vault". If you have=20 loose soil, the best remote and least watered/susceptible=20 area would be best.=20 The best material seems to be a "pier" of concrete, that can=20 be inside/outside weather enclosed and somewhat isolated from=20 domestic seismic sources of "noise"......or....if not possible=20 to do so, one would have to live with the noise it generates;=20 which is usually easy to denote with time/experience. The=20 pier usually needs to "fit" the area required by the sensor/s=20 anticipated. The thickness of the concrete slab can be=20 debated I suppose, but I'd try for whatever depth/thickness=20 you can squeeze in the spot you chose. I use about a 7-8"=20 thickness of my three piers....which are in reality cast concrete=20 pavers stacked together but layered in the joints and surfaces=20 with real concrete. I chose this as it was near impossible to=20 mix massive concrete on my knees under the house, let alone=20 move all the sand/concrete therein. For myself, I elected to=20 also use thick mylar sheet under the piers, to limit water=20 absorbion into the piers. I even used a water repellent paint=20 on the pier/s to limit water absorbtion. Even after completion,=20 you can expect a period of time before the piers stabilize from=20 curing....perhaps acouple months. If you can make the pier=20 thickness even greater than say...6 inches thick, I'd do so. Do=20 not use iron, steel in the pier.=20 Personally I live in Denver, and in a city lot.....so, I use my=20 house soil crawlspace for pier/seismometer placements. I=20 also enclosed the piers with walls and insulation to somewhat=20 limit temperature excursion that do occur. Among the PSN=20 members....we kind of all utilize whats available.....=20 So....in a way....everything gets back to what space you=20 have now that could be utilized. Next, the physical size of=20 your anticipated seismos you're planning on building/using.=20 I think you're right to get into the seismo housing/piers aspect=20 right off the bat.....if one doesn't; than they will get into alot of=20 soil tilt, water, weather, temperature related problems that will=20 make any consistent seismic monitoring rather useless otherwise.=20 Suggest that any pier/containment is well built and temperature=20 insulated; this can take time, but it would pay off in the long=20 run.=20 Outside of the above,.....what kind of seismic sensors are you=20 planning on using.....the instrumentation sensor aspect is always=20 interesting.=20 Take care, Meredith Lamb=20 "Jan D. Marshall" wrote:=20 I am starting to design my sensors and electronics and have decided = that I understand the requirments there pretty well -- what I don't have = a very good understanding on is what do I need for a base or foundation = to set the sensors on. What type of mass does it need? does it need to = set on bedrock? I do not have any cement slab floors. Thanks Jan D. = Marshall=20 Nampa, Idaho=20 jandmarshall@...............My first attempt is going to be a = Lehman. I=20 am not afraid to tackle anything however. As soon as I get an amp, = filter,=20 A/D converter and the PC software going I thing it is going to be fun=20 expermiting with different sensors.Subject: Pendulum Periods From: "Jan D. Marshall" jandmarshall@............ Date: Fri, 5 Oct 2001 21:53:40 -0600 Could some one give me a quick 101 course on what is ment by the "period of the pendulum" how does that relate to a seismograph, what period are we striving for? Jan D. Marshall Nampa, Idaho jandmarshall@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Pendulum Periods From: Karl Cunningham karlc@.......... Date: Sun, 07 Oct 2001 12:32:30 -0700 Hi Jan -- I'll take a stab at it... I don't know anything about your level of knowledge of math and physics, and the following may be too elementary or too complex, but please let me know if you want more explanation. Take a string about 3 feet long and tie a weight at one end (a shoe would work). Hold the string by the other end and let the weight dangle down without hitting anything. Then have someone pull the weight a bit to the side (keeping the string taut) and let it go. It will swing back an forth, and the time it takes it to go from one end over and back to the same place again is the period. The period of a simple pendulum (one with only one weight on it and a string that weighs little compared to the weight, is given by the following equation: T = 2 * pi * sqrt(L / G) The variables are: T is time in seconds, pi is the constant 3.14159... , sqrt is an abreviation for square root, L is the length of the string from the pivot to the center of mass of the weight, and G is the acceleration of gravity. If L is expressed in inches, the acceleration of gravity should be 386.1 inches per second squared. You really don't need to worry about the units if you use the length in inches, and use 386.1 for gravity. For example, use a length of 30 inches. Take 30 and divide it by 386.1 to get 0.0777. Take the square root of that to get 0.2787. Then multiply the result by 3.14159 and result of that by 2, to get 1.751 second. So a 30" long pendulum will take about 1.75 seconds to swing over and back to the same place. That is its period. When making a seismometer the longer the period of the pendulum the longer the period of the waves that can be measured. Usually, this is desireable. Regards, Karl Cunningham --On Friday, October 05, 2001 21:53 -0600 "Jan D. Marshall"----- Original Message -----From:=20 meredith = lamb=20Sent: Friday, October 05, 2001 = 12:41=20 AMSubject: Re: What type of=20 foundationHi Jan,=20Perhaps.....the most important aspect is,....what kind of =
terrain=20 and/or space do you have available....i.e, city/country,
to place = any=20 seismo on. Any house crawlspace available, or
garage, shed, = or least=20 disturbed area of land around? One
will have to make "do" = with what=20 they have for placement.
If you do indeed have bedrock, that would = be a=20 plus....if...its
convenient and adaptable for a seismic = "vault". If=20 you have
loose soil, the best remote and least watered/susceptible =
area would be best.=20The best material seems to be a "pier" of concrete, that can
be = inside/outside weather enclosed and somewhat isolated from =
domestic=20 seismic sources of "noise"......or....if not possible
to do so, = one would=20 have to live with the noise it generates;
which is usually easy to = denote=20 with time/experience. The
pier usually needs to "fit" the = area=20 required by the sensor/s
anticipated. The thickness of the = concrete=20 slab can be
debated I suppose, but I'd try for whatever = depth/thickness=20
you can squeeze in the spot you chose. I use about a 7-8"=20
thickness of my three piers....which are in reality cast concrete=20
pavers stacked together but layered in the joints and surfaces =
with=20 real concrete. I chose this as it was near impossible to
mix = massive=20 concrete on my knees under the house, let alone
move all the = sand/concrete=20 therein. For myself, I elected to
also use thick mylar sheet = under=20 the piers, to limit water
absorbion into the piers. I even = used a=20 water repellent paint
on the pier/s to limit water = absorbtion. Even=20 after completion,
you can expect a period of time before the piers = stabilize from
curing....perhaps acouple months. If you can = make the=20 pier
thickness even greater than say...6 inches thick, I'd do = so. Do=20
not use iron, steel in the pier.=20Personally I live in Denver, and in a city lot.....so, I use my =
house=20 soil crawlspace for pier/seismometer placements. I
also = enclosed the=20 piers with walls and insulation to somewhat
limit temperature = excursion=20 that do occur. Among the PSN
members....we kind of all = utilize whats=20 available.....=20So....in a way....everything gets back to what space you
have = now that=20 could be utilized. Next, the physical size of
your = anticipated=20 seismos you're planning on building/using.=20I think you're right to get into the seismo housing/piers aspect =
right=20 off the bat.....if one doesn't; than they will get into alot of =
soil tilt,=20 water, weather, temperature related problems that will
make = any=20 consistent seismic monitoring rather useless otherwise.
Suggest = that any=20 pier/containment is well built and temperature
insulated; this can = take=20 time, but it would pay off in the long
run.=20Outside of the above,.....what kind of seismic sensors are you =
planning=20 on using.....the instrumentation sensor aspect is always =
interesting.=20Take care, Meredith Lamb=20
"Jan D. Marshall" wrote:=20
I am starting to design my = sensors and=20 electronics and have decided that I understand the requirments there = pretty=20 well -- what I don't have a very good understanding on is what do I = need for=20 a base or foundation to set the sensors on. What type of mass = does it=20 need? does it need to set on bedrock? I do not have any cement = slab=20 floors. Thanks=20 Jan D. Marshall
Nampa, Idaho
jandmarshall@............=20wrote: > Could some one give me a quick 101 course on what is ment by the > "period of the pendulum" how does that relate to a seismograph, > what period are we striving for? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ADXL202 From: "Larry Cochrane" cochrane@.............. Date: Sun, 7 Oct 2001 15:11:05 -0700 Hi Angel, The new chips are based on the same technology as the original ADX05 sensor. These devices are too noisy for general seismology. Since their dynamic range is pretty poor they could only be used as a very strong motion sensor. I am looking into making a sensor based on another type of accelerometer chip made by Measurement Specialties Inc. Here is a link to the sensor http://www.msiusa.com/icsensors/catalog/data/accel/M_3052.pdf. I currently have one on-line, the sensor ID is *.lctsn.psn. So far I have recorded two small events with the new sensor. The first was a Md2.5. Here's a link to the PSN file: ftp://ftp.seismicnet.com/quakes/0110/011002.0057.lctsn.psn. The second event was a Ml3.1 both where 34km from me. The sensor recorded the second event very nicely. Here's a link to the PSN file: ftp://ftp.seismicnet.com/quakes/0110/011006.0215.lctsn.psn. I currently have the gain between the sensor and the A/D board set to +- 0.1 g max. By having two outputs per axis one could have a strong motion (+- 2.0 g ) channel with and a high gain channel for monitoring smaller events. The problem is the cost of the sensor chip is rather high at $195.00 each. The price goes down to $114.00 in quantities of 25. Digi-Key is now selling them, but they are out of stock because I just purchased the last 8 devices they had in-stock. -Larry Cochrane Redwood City, PSN ----- Original Message ----- From: "angel@volcanbaru" To: "Larry Cochrane" Sent: Sunday, October 07, 2001 4:18 AM Subject: ADXL202 > Hello Larry, > > I can't post to the list when I travel because my isp in Panama will > relay and the list does not accept mail from this email address. > > Has there been any revisiting of using some of Analog Devices new > chips. Check out this page > > http://www.edtn.com/embapps/emba065.htm > > I am now in my "vacation" time and only check mail now and then. > > > Best regards, > angel > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: New WinQuake beta release From: "Larry Cochrane" cochrane@.............. Date: Sun, 7 Oct 2001 18:54:22 -0700 All, I just released a new version of WinQuake. The new beta is version 2.8.2 with a release date of 10/06/01. This release fixes several bugs around the report handling feature of WQ. There is still one problem with WQ that I have not been able to fix. This is the location map printing problem. You can download the release here: http://www.seismicnet.com/software.html. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Received Shipment From: Jim ODonnell jimo17@........ Date: Sun, 7 Oct 2001 21:25:28 -0700 Hi Larry- I got the last of my order on Thursday and all looks good. The new Filt/amp bords with their 15V PS is nice. Thanks........Jim ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Information Needed From: CapAAVSO@....... Date: Thu, 11 Oct 2001 09:42:44 EDT Hi All, Can someone please tell me the name of the hardware company Sean - Thomas often recommended as a source of materials to build seismometers? Thanks, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Information Needed From: Doug Crice dcrice@............ Date: Thu, 11 Oct 2001 06:49:56 -0700 McMaster-Carr, web site http://www.mcmaster.com But if you can get one of their 3-inch catalogs, it's hours of great browsing. CapAAVSO@....... wrote: > > Hi All, > > Can someone please tell me the name of the hardware company Sean - Thomas > often recommended as a source of materials to build seismometers? > > Thanks, > Cap > __________________________________________________________ > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Information Needed From: CapAAVSO@....... Date: Thu, 11 Oct 2001 11:51:30 EDT In a message dated 10/11/01 2:50:31 PM GMT Daylight Time, dcrice@............ writes: << McMaster-Carr, web site http://www.mcmaster.com But if you can get one of their 3-inch catalogs, it's hours of great browsing. >> Thanks Doug, They are the only company I know that sells Alnico 8 magnets. I just placed an order for some magnets for the torsion balance magnetometer I'm building. Alnico 8 is the best because it has the least sensitivity to temperature changes. Torsion balance magnetometers tend to drift with temperature changes and this is kept to a minimum by using Alnico 8 magnets. Thanks again' Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: my mail From: "Bryan&Regina Goss" bgoss@.................. Date: Tue, 23 Oct 2001 05:16:44 -0500 Just a test havent heard anything in a while Just a test havent = heard anything=20 in a while Subject: UNSUBSCRIBE From: Mike Lozano mikel@............... Date: Tue, 23 Oct 2001 21:35:21 -0500 UNSUBSCRI BE __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PSN mailing list From: "Larry Cochrane" cochrane@.............. Date: Mon, 29 Oct 2001 15:54:30 -0800 Rick, There haven't been any post to the list in the past few days. You should see this message coming from the PSN-L list and from me directly. -Larry Cochrane Redwood City, PSN ----- Original Message ----- From: "Richard Phillips" To: Sent: Monday, October 29, 2001 3:46 PM Subject: PSN mailing list > Dear Larry, > > please make sure that I am still on PSN mailing list. I have not > received any e-mail for several days. > > Thanks, > > Rick Phillips > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PSN mailing list From: johnc c cole johnccole1@........ Date: Mon, 29 Oct 2001 18:44:29 -0600 Larry, I was also worried about the inactivity on PSN . This note is to let everyone know that I am also alive and well . John C Cole, Pearland, Texas ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PSN mailing list From: ChrisAtUpw@....... Date: Mon, 29 Oct 2001 21:14:35 EST John Cole talking of his good health reminds me that it might be a good moment to ask how Sean Thomas Morrissey is recovering? Wish him well anyway. Regards, Chris Chapman John Cole talking of his good health reminds me that it might be a good moment to ask how Sean Thomas Morrissey is recovering? Wish him well anyway.
Regards,
Chris Chapman Subject: close event From: ian ian@........... Date: Mon, 29 Oct 2001 16:35:32 -1000 I've just been "rocked" by a 3.1 1.5 miles from my sensor. I didn't feel anything and the trace superficially looks like surface noise. I've uploaded the event, 011029.1942.hl0.psn. I'm puzzled by such a close event of moderate strength going by so un-noticed. I Smith __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: close event From: "Larry Cochrane" cochrane@.............. Date: Mon, 29 Oct 2001 19:51:54 -0800 I too had a close event the other day. The event was a MD2.2 right here in Redwood City. The non felt event was ~ 4km or ~2 miles from me. I think this is the closes event I have ever recorded. I was lucky to record it on all of my sensors. I just got done with rearranging my station. The even happened only 15 minutes after I got my system back on line. Recently I added a second channel based on the IDS3052 accelerometer chip. This channel is oriented vertically and it recorded the event very nicely. The event file is 011027.0618.lctsz.psn. Here's an update on the new accelerometer sensor board based on the IDS3052 chip. I hope to be selling it soon. I completed the PC board layout last week. I should be getting 10 PC boards in a few days. Once I verify that the board works, I will be sending out a email message to the list as well as make a web page documenting the new product. -Larry Cochrane Redwood City, PSN ----- Original Message ----- From: "ian"To: Subject: Re: laser seismograph From: CapAAVSO@....... Date: Wed, 7 Nov 2001 07:43:48 EST In a message dated 11/7/01 8:13:18 AM GMT Standard Time, westfall@........ writes: > I have a copy of the Laser Cookbook. I got it because I was intrigued by > the idea of a laser-based seismograph. Hi Ron, Is the laser cookbook still available? If so, where can I buy a copy? Thanks, Cap In a message dated 11/7/01 8:13:18 AM GMT Standard Time, westfall@........ writes:Sent: Monday, October 29, 2001 6:35 PM Subject: close event > I've just been "rocked" by a 3.1 1.5 miles from my sensor. I didn't > feel anything and the trace superficially looks like surface noise. > > I've uploaded the event, 011029.1942.hl0.psn. I'm puzzled by such a > close event of moderate strength going by so un-noticed. > > I Smith > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: lines From: "JORD" jord@............ Date: Tue, 30 Oct 2001 23:30:46 -0500 Can high voltage power lines have an effect on how my sensor works? The lines are about 250-300 feet away. Whitby Ontario now .=20 Formaly from Toronto. Thank You Randy....................... Can high voltage power lines have an = effect on how=20 my sensor works?The lines are about 250-300 feet = away.Whitby Ontario now .Formaly from Toronto.Thank YouRandy.......................Subject: Re: lines From: "Erich Kern" efkern@............. Date: Tue, 30 Oct 2001 20:40:32 -0800 Randy, Not likely to affect the sensor directly, but the broadband RF interference that those lines radiate could get into the electronics if your signal lines are not shielded. What are you observing that might be interference? Regards, Erich ----- Original Message ----- From: "JORD"To: Sent: Tuesday, October 30, 2001 8:30 PM Subject: lines Can high voltage power lines have an effect on how my sensor works? The lines are about 250-300 feet away. Whitby Ontario now . Formaly from Toronto. Thank You Randy....................... __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: lines From: ChrisAtUpw@....... Date: Wed, 31 Oct 2001 20:25:54 EST In a message dated 31/10/01, jord@............ writes: > Can high voltage power lines have an effect on how my sensor works? > The lines are about 250-300 feet away. > Dear Randy, If you tell us what type of sensor you are using and something about your setup, where the sensor is, how long the cables are, the size of the power line towers, your observations of the effects, etc., we may be able to help. The short answer is that interference is possible. There are two types:- electrical / RF interference / switching transients and wind sway on the electricity pylons. However, you can also get wind generated effects on a house and from nearby trees. I put a wind speed sensor outside and was able to clearly identify wind effects on my very solidly built old house. Regards, Chris Chapman In a message dated 31/10/01, jord@............ writes:
Can hi gh voltage power lines have an effect on how my sensor works?
The lines are about 250-300 feet away.
Randy.
Dear Randy,
If you tell us what type of sensor you are using and something about your setup, where the sensor is, how long the cables are, the size of the power line towers, your observations of the effects, etc., we may be a ble to help. The short answer is that interference is possible. There are two types:- electrical / RF interference / switching transients and wind sway on the electricity pylons. However, you can also get wind generated effects on a house and from nearby trees. I put a wind speed sensor outside and was able to clearly identify wind effects on my very solidly built old house. &nb sp;
Regards,
Chris Chapman Subject: Fw: Quake Warnings Before the Shaking Starts From: "Larry Cochrane" cochrane@.............. Date: Sun, 4 Nov 2001 12:53:00 -0800 From Jim O'Donnell. -Larry ----- Original Message ----- From: Jim ODonnell To: cochrane@.............. Sent: Sunday, November 04, 2001 11:28 AM Subject: Quake Warnings Before the Shaking Starts Larry- Could you post this for the group.... You should get some hits from this article. It is a Shaky Business, but you guys are looking good!...Jim Quake Warnings Before the Shaking Starts Early-warning systems for people in earthquake zones are growing closer to real time The ham seismology community has an important place in this picture, too. The Public Seismic Network (PSN) is the longtime home of this ingenious group of amateurs. Maybe you could visit and bookmark the PSN Web site at http://psn.quake.net/. See: http://geology.about.com/library/weekly/aa011198.htm __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: KINEMETRICS SEISMIC SENSOR From: RADIOTEL@....... Date: Sun, 4 Nov 2001 21:24:01 EST TO: ALL LIST MEMBERS There is a Kinemetrics TS-3 Seismic Sensor on Ebay #1657596668. Current bid is $102.00. I have no idea whether it is a strong motion sensor, long period sensor or broad band sensor. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: KINEMETRICS SEISMIC SENSOR From: Doug Crice dcrice@............ Date: Mon, 05 Nov 2001 07:01:01 -0800 I believe that this is a 3-component force balance accelerometer. Kinemetrics made them from scratch in order to produce a reasonably-priced product. It triggers on an earthquake and sends analog data to a central recording system. It predates modern MEMS accelerometers, will only detect strong local earthquakes, and should only be purchased for a lot less than this vendor thinks it's worth. I'm sure Larry's system will be better and reasonably priced. RADIOTEL@....... wrote: > > TO: ALL LIST MEMBERS > There is a Kinemetrics TS-3 Seismic Sensor on Ebay #1657596668. Current bid > is $102.00. I have no idea whether it is a strong motion sensor, long period > sensor or broad band sensor. > __________________________________________________________ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: laser seismograph From: R&L Thompson rlthompson@................. Date: Tue, 06 Nov 2001 15:34:05 -0330 I'd appreciate comments regarding this seismograph design using a laser. http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm I'm unqualified to say much about it, but I'm doubtful that it would be very sensitive. Ron (in Gander) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: "morris" morris@....... Date: Tue, 6 Nov 2001 11:39:39 -0800 Let me know if you find any info on the laser seismo. I have thought of using something like this. Ron Suttora (Livermore) morris@....... ----- Original Message ----- From: R&L ThompsonTo: PSN List Sent: Tuesday, November 06, 2001 11:04 AM Subject: laser seismograph > I'd appreciate comments regarding this seismograph design using a laser. > > http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm > > I'm unqualified to say much about it, but I'm doubtful that it would be > very sensitive. > > Ron (in Gander) > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: "ravakian" ravakian@............ Date: Tue, 6 Nov 2001 15:03:25 -0600 As shown I can't see how there would be any sensitivity at all, but what about try stretching it out straight for a number of feet, say at least 1/4 wavelength? Even then the big problem I see is the non-directionality of the device. How do you tell horizontal from vertical motion and either from a sag of the cable due to towards and away motion? Bob Avakian Tulsa, OK ---- Original Message ---- From: morris@....... To: psn-l@............... Subject: Re: laser seismograph Date: Tue, 6 Nov 2001 11:39:39 -0800 >Let me know if you find any info on the laser seismo. >I have thought of using something like this. > >Ron Suttora (Livermore) >morris@....... >----- Original Message ----- >From: R&L Thompson >To: PSN List >Sent: Tuesday, November 06, 2001 11:04 AM >Subject: laser seismograph > > >> I'd appreciate comments regarding this seismograph design using a >laser. >> >> http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm >> >> I'm unqualified to say much about it, but I'm doubtful that it >would be >> very sensitive. >> >> Ron (in Gander) >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: R&L Thompson rlthompson@................. Date: Tue, 06 Nov 2001 17:47:37 -0330 Correct me if I'm wrong, but I think that 1/4 wavelength for an He laser would be less than the diameter of the fiber, not much of a stretch. Ron ravakian wrote: > As shown I can't see how there would be any sensitivity at all, but > what about try stretching it out straight for a number of feet, say > at least 1/4 wavelength? Even then the big problem I see is the > non-directionality of the device. How do you tell horizontal from > vertical motion and either from a sag of the cable due to towards and > away motion? > > Bob Avakian > Tulsa, OK > ---- Original Message ---- > From: morris@....... > To: psn-l@............... > Subject: Re: laser seismograph > Date: Tue, 6 Nov 2001 11:39:39 -0800 > > >Let me know if you find any info on the laser seismo. > >I have thought of using something like this. > > > >Ron Suttora (Livermore) > >morris@....... > >----- Original Message ----- > >From: R&L Thompson > >To: PSN List > >Sent: Tuesday, November 06, 2001 11:04 AM > >Subject: laser seismograph > > > > > >> I'd appreciate comments regarding this seismograph design using a > >laser. > >> > >> http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm > >> > >> I'm unqualified to say much about it, but I'm doubtful that it > >would be > >> very sensitive. > >> > >> Ron (in Gander) > >> > >> > >> __________________________________________________________ > >> > >> Public Seismic Network Mailing List (PSN-L) > >> > >> To leave this list email PSN-L-REQUEST@.............. with > >> the body of the message (first line only): unsubscribe > >> See http://www.seismicnet.com/maillist.html for more information. > > > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: ChrisAtUpw@....... Date: Tue, 6 Nov 2001 19:42:06 EST A LASER SEISMOGRAPH EE488 Department of Electrical Engineering University of Washington Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard Anderson Hi All, With the date 1994, there should be some record if this was ever tried and what, if any, results were obtained. The article seems to lack any logical relationship between a mechanical vibration and the 'noise' on the output. The use of a lot of long words and a 741 amplifier does not immediately inspire confidence in the scholarship of the proposal. Perhaps someone who has a copy of the 'Laser Cookbook' would look it up the text associated with Fig 16-9 and comment, please? Regards, Chris Chapman A LASER SEISMOGRAPH
Subject: Re: laser seismograph From: "Al Allworth" allworth@.............. Date: Tue, 6 Nov 2001 18:28:29 -0800 Hi, This looks like it might be a poorly thought out attempt to build a = device similar to the laser ring detectors tried by those in New Zealand and elsewhere.EE488
Department of Electrical Engineering
University of Washington
Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard Anderson
Hi All,
With the date 1994, there should be some record if this was ever tried and what, if an y, results were obtained. The article seems to lack any logical relationship between a mechanical vibration and the 'noise' on the output. The use of a lot of long words and a 741 amplifier does not immediately inspire confidence in the scholarship of th e proposal. Perhaps someone who has a copy of the 'Laser Cookbook' would look it up the text associated with Fig 16-9 and comme nt, please?
Regards,
Chris ChapmanHi,This looks like it might be a poorly thought out = attempt to=20 build a device similar tothe laser ring detectors tried by those in New = Zealand=20 and elsewhere.Subject: Re: laser seismograph From: "Larry Cochrane" cochrane@.............. Date: Tue, 6 Nov 2001 18:40:43 -0800 I like the 741 op-amp circuit. It has three different ways of = controlling the gain! -Larry Cochrane Redwood City, PSN ----- Original Message -----=20 From: Al Allworth=20 To: psn-l@................. Sent: Tuesday, November 06, 2001 6:28 PM Subject: Re: laser seismograph Hi, This looks like it might be a poorly thought out attempt to build a = device similar to the laser ring detectors tried by those in New Zealand and elsewhere.I like the 741 op-amp circuit. It has = three=20 different ways of controlling the gain!-Larry CochraneRedwood City, PSNSubject: Re: laser seismograph From: John Hernlund hernlund@............ Date: Tue, 06 Nov 2001 18:48:47 -0800 A friend of mine has co-developed a laser seismograph. Really, it is a strain meter. The way it works is to lay out a long line of fiber optic cable and bounce light signals. One end is reflecting, while the other end has a transmitter/receiver. The "time of flight" variations give you the change in length. Dividing the change in length by the over all length gives the strain as a function of time. His large prototype is buried in his back yard in Kansas... He caught on to this while gabbing with an engineer who uses this same technique to measure strain in structures (eg. bridges) and apparently it works quite well. They are working on a proposal to rent fiber optics communications lines and hook this stuff up...it could be a lot of fun. The longer term arm-waving goal is to eventually measure precursory strain transients near an active fault (eg. San Andreas). They could also work on other fun problems with sufficient sensitivity, such as the Chandler wobble... Most people I have known prefer an interferometric method to time of flight methods, but I am not sure how each technique stacks up against the other with the current technology. The interferometric method uses a steady transmitted signal and measures the relative interference of the waves to back out the changes in length. For a laser with a wavelength around 500 nm, the resolution is a small fraction of this. Averaged out over a very long cable, this would allow very small strains to be measured. The nice thing about these types of instruments is that they are truly broadband...limited only by the number and frequency of measurements. The astronomers working on binocularizing the Keck scope have run into difficulties in connecting the two sources via an underground tunnel...this also uses interferometric methods. I wonder how they are doing now; whether they have fixed this problem or not. It may be interesting to find out how they fix it all, since the Keck could easily become a strain meter as well as a bad ass telescope when they do figure it out. Cheers! John Hernlund Department of Earth and Space Sciences University of California, Los Angeles http://geodyn.ess.ucla.edu/~hernlund/ hernlund@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: "ed thelen" ethelen@........ Date: Tue, 6 Nov 2001 20:52:33 -0800 You have me curious - How is the 747 different from any other noisy, drifty, hi-input current, op-amp from the early 1970's ?? Feedback is feedback isn't it? The modern op-amp designs seem so much better. "I'd walk a mile for a camel - no no that should be chopper stabilization." (And I have used my share of 747's when they were about the only game in town "for the rest of us".) Cheers Ed Thelen ----- Original Message ----- > From: "Larry Cochrane"----- Original Message -----From:=20 Al=20 AllworthSent: Tuesday, November 06, = 2001 6:28=20 PMSubject: Re: laser = seismographHi,This looks like it might be a poorly thought out = attempt to=20 build a device similar tothe laser ring detectors tried by those in = New Zealand=20 and elsewhere.> > I like the 741 op-amp circuit. It has three different ways of controlling the gain! > > -Larry Cochrane > Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: laser seismograph From: "Larry Cochrane" cochrane@.............. Date: Tue, 6 Nov 2001 22:32:45 -0800 Ed, I wasn't commenting on the type of op-amp. Obviously there are a lot better op-amps then the 741. What I was commenting on was the three gain control pots. -Larry ----- Original Message ----- From: "ed thelen" To: Sent: Tuesday, November 06, 2001 8:52 PM Subject: Re: laser seismograph > You have me curious - > How is the 747 different from any other noisy, drifty, hi-input current, > op-amp from the early 1970's ?? > > Feedback is feedback isn't it? > > The modern op-amp designs seem so much better. > "I'd walk a mile for a camel - no no that should be chopper stabilization." > > (And I have used my share of 747's when they were about > the only game in town "for the rest of us".) > > Cheers > Ed Thelen > > ----- Original Message ----- > > From: "Larry Cochrane" > > > > I like the 741 op-amp circuit. It has three different ways of controlling > the gain! > > > > -Larry Cochrane > > Redwood City, PSN > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: laser seismograph From: "Ron Westfall" westfall@........ Date: Tue, 6 Nov 2001 23:12:35 -0800 Hi I have a copy of the Laser Cookbook. I got it because I was intrigued by the idea of a laser-based seismograph. The web page that Ron Thompson referred us to was for a class project (presumably for a class that dealt with lasers). Some of the other projects look interesting by the way. It looks like the two students who wrote the web page pretty much borrowed the design directly from the Laser Cookbook. Apparently, in a stepped-index fiber, laser light travels through the fiber in several groups of light beams. At the transmitting laser, all the light beams have exactly the same phase (a basic property of laser light known as coherency). As the light beams travel along the stepped-index fiber, the phase of each group of light beams changes relative to the other groups. Apparently, if the fiber is long enough, the light coming out the far end is completely incoherent (i.e. the optical equivalent of mush, or ordinary light). By using only 10 - 20 feet of fiber in the seismograph, coherency is only partly degraded. When the laser light is detected by a phototransistor and the resulting electrical signal is amplified, the slight differences in phase relationship between the groups of light beams creates low frequency audio noise. Based on the description given in the Laser Cookbook, I am guessing that the audio noise is fairly constant in the absence of changes in geometry of the fiber. The changes in phase relationship are sensitive to length of the fiber as mentioned and curvature. I wouldn't be surprised if temperature causes changes as well. Vibration dynamically changes the curvature of the fiber causing dynamic changes in phase relationship. The audio noise generated by the phototransistor changes. The Laser Cookbook mentions that the noise "changes pitch and makes odd thuds, pings, and thrums". The Cookbook does not provide a precise analysis of the changes in phase relationship, so the mathematical relationship between the changing noise and the original vibration is unclear. Figure 4 (16-3 in the Cookbook) gives the mechanical structure of the seismograph. As Bob Avakian has pointed out, the device is non-directional because the fiber is wound around four bolts in a rectangle, so the fiber will have both N-S and E-W components of motion. Because the fiber can move in a vertical direction, there will also be a vertical component. Some degree of directionality could be achieved by using only two bolts oriented in a N-S or E-W direction. You would unfortunately still have a vertical component mixed in. The other problem I can see is that the fiber motion is not damped. Figure 5 (15-9 in the Cookbook) provides the schematic for the phototransistor and amplifier. In Figure 15-9 in the Cookbook there is an LM386 audio amplifier chip that is fed by the output of the LM741. In Figure 5 from the web page, the potentiometer wiper output lead is connected to the positive input of the 386 and the negative input of the 386 is grounded as indicated by the other output lead in Figure 5. The output of the 386 is capactively coupled (220 uF) to a headphone jack. The author of the cookbook built the seismograph and detected a quake in the Los Angeles area on October 1, 1987. The M6.1 quake was 50 miles away from the seismograph. Hopefully that was interesting. If you have any other questions that I can answer by digging through the Cookbook, let me know. Ron Westfall -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of ChrisAtUpw@....... Sent: Tuesday, November 06, 2001 4:42 PM To: psn-l@.............. Subject: Re: laser seismograph A LASER SEISMOGRAPH EE488 Department of Electrical Engineering University of Washington Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard Anderson Hi All, With the date 1994, there should be some record if this was ever tried and what, if any, results were obtained. The article seems to lack any logical relationship between a mechanical vibration and the 'noise' on the output. The use of a lot of long words and a 741 amplifier does not immediately inspire confidence in the scholarship of the proposal. Perhaps someone who has a copy of the 'Laser Cookbook' would look it up the text associated with Fig 16-9 and comment, please? Regards, Chris Chapman HiI have=20 a copy of the Laser Cookbook. I got it because I was intrigued by = the idea=20 of a laser-basedseismograph.The=20 web page that Ron Thompson referred us to was for a class project = (presumably=20 for a classthat=20 dealt with lasers). Some of the other projects look interesting by = the=20 way. It looks like the twostudents who wrote the web page pretty much borrowed the design = directly=20 from the LaserCookbook.Apparently, in a stepped-index fiber, laser light travels = through the=20 fiber in several groups of lightbeams. At the transmitting laser, all the light beams = have exactly=20 the same phase (a basic propertyof=20 laser light known as coherency). As the=20 light beams travel along the stepped-index fiber, = thephase=20 of each group of light beams changes relative to the other groups. = Apparently, if the fiberis=20 long enough, the light coming out the far end is completely incoherent = (i.e. the=20 optical equivalentof=20 mush, or ordinary light).By=20 using only 10 - 20 feet of fiber in the seismograph, = coherency is only=20 partly degraded. Whenthe=20 laser light is detected by a phototransistor and the resulting = electrical=20 signal is amplified, theslight=20 differences in phase relationship between the groups of light beams=20 creates low frequencyaudio=20 noise. Based on the description given in the Laser Cookbook, I am = guessing=20 that the audionoise=20 is fairly constant in the absence of changes in geometry = of the=20 fiber.The=20 changes in phase relationship are sensitive to length of the fiber as = mentioned=20 and curvature.I=20 wouldn't be surprised if temperature causes changes as well. =20 Vibration dynamically changesthe=20 curvature of the fiber causing dynamic changes in phase = relationship. The audio noisegenerated by the phototransistor changes. The Laser = Cookbook=20 mentions that the noise "changespitch=20 and makes odd thuds, pings, and thrums". The Cookbook does not = provide a=20 preciseanalysis of the changes in phase relationship, so the = mathematical=20 relationship between thechanging noise and the original vibration is = unclear.Figure=20 4 (16-3 in the Cookbook) gives the mechanical structure of the=20 seismograph. As BobAvakian has pointed out, the device is non-directional because = the fiber=20 is wound aroundfour=20 bolts in a rectangle, so the fiber will have both N-S and E-W components = of=20 motion. Becausethe=20 fiber can move in a vertical direction, there will also be a vertical=20 component.Some=20 degree of directionality could be achieved by using only two=20 bolts oriented in a N-S or E-Wdirection. You would unfortunately still have a vertical = component=20 mixed in. The other problem Ican=20 see is that the fiber motion is not damped.Figure=20 5 (15-9 in the Cookbook) provides the schematic for the phototransistor = and=20 amplifier. InFigure=20 15-9 in the Cookbook there is an LM386 audio amplifier chip that is fed = by the=20 output ofthe=20 LM741. In Figure 5 from the web page, the potentiometer wiper = output lead=20 is connected to thepositive input of the 386 and the negative input of the 386 is = grounded=20 as indicated by the otheroutput=20 lead in Figure 5. The output of the 386 is capactively coupled = (220 uF) to=20 a headphonejack.The=20 author of the cookbook built the seismograph and detected a quake in the = Los=20 Angeles areaon=20 October 1, 1987. The M6.1 quake was 50 miles away from the=20 seismograph.Hopefully that was interesting. If you have any other = questions=20 that I can answer by diggingthrough the Cookbook, let me know.Ron=20 Westfall-----Original Message-----
From: = psn-l-request@................. [mailto:psn-l-request@...............On Behalf Of=20 ChrisAtUpw@.......
Sent: Tuesday, November 06, 2001 4:42 = PM
To: psn-l@..............
Subject: Re: laser=20 seismographA LASER SEISMOGRAPH
EE488
Department of Electrical Engineering=20
University of Washington
Autumn Quarter, 1994 Proposal = prepared by:=20 Leslie Woitte and Richard Anderson
Hi All,=20
With the date 1994, there = should be=20 some record if this was ever tried and what, if any, results were = obtained.=20 The article seems to lack any logical relationship between a = mechanical=20 vibration and the 'noise' on the output. The use of a lot of long = words and a=20 741 amplifier does not immediately inspire confidence in the = scholarship of=20 the proposal. Perhaps someone who has a copy of the 'Laser Cookbook' = would=20 look it up the text associated with Fig 16-9 and comment, please?=20
Regards,=20
Chris Chapman
I have a copy of the Lase r Cookbook. I got it because I was intrigued by the idea of a laser-basedseismograph.