Author Topic: Shetland Attack Pony  (Read 17270 times)

Offline Bob Smith

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Re: Shetland Attack Pony
« Reply #25 on: January 02, 2008, 04:42:54 pm »
As long as you have a good base line, you can conduct a survey using just mag and dec, working in triangles, and then work out the distances using 3d trig.

In theory that's great, but that's not really practical in most UK caves is it, fine if you are working with a sub minute instrument, with a stable setup, long survey legs etc, but it relies on intervisibilty of survey stations and it's an awful lot of hard work even for an experienced surveyor. A disto would be just fine and @ around £125 a pop not too far out of reach either.

Offline Cave_Troll

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Re: Shetland Attack Pony
« Reply #26 on: January 02, 2008, 04:49:51 pm »
i did mean to put "in theory" sorry

Offline Rob

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Re: Shetland Attack Pony
« Reply #27 on: January 02, 2008, 05:26:46 pm »
Surveying Solo... obviously need a disto as no one to hold the tape measure...

Earlier this week i prooved this wrong. With a nicley sized rock to weigh down the end of the tape and a bit of thought about station possitioning it is possible.

However I was in a stupidly tight bit of passage though so would have been much nicer with a disto / friend.  :down:
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Offline graham

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Re: Shetland Attack Pony
« Reply #28 on: January 02, 2008, 05:33:28 pm »
As long as you have a good base line, you can conduct a survey using just mag and dec, working in triangles, and then work out the distances using 3d trig.

In theory that's great, but that's not really practical in most UK caves is it, fine if you are working with a sub minute instrument, with a stable setup, long survey legs etc, but it relies on intervisibilty of survey stations and it's an awful lot of hard work even for an experienced surveyor. A disto would be just fine and @ around £125 a pop not too far out of reach either.

For the truly obscure, I believe that Alfie Collins did the 1950s survey of Redcliffe caves using a plane table. I've used that method to draw surface features but can think of very few UK caves where it might be feasible.
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Offline menacer

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Re: Shetland Attack Pony
« Reply #29 on: January 02, 2008, 05:50:07 pm »
Wow thanks for all that info guys...
So all I really needed was a slide rule, a protractor and a stick with a plumb line, a 6 inch ruler and a compass made out of  a bowl of water, a piece of cork, any magnet, and a needle.
Can anyone suggest a suitable parchment and quill for drawing it all up. :lol:
Oh and dont forget the large rock...
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Offline CaversLass

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Re: Shetland Attack Pony
« Reply #30 on: January 02, 2008, 06:36:47 pm »
I was at a lecture recently where Trevor Faulkner recounted his one man method for surveying caves in Norway. Apparently he finds it is necessary when on expedition to Norway as he is normally on his own (obviously a billy no mates).  ;D

He was getting fairly good results though using a tape and a rock, also using a magnetic compass and clino.

Offline ian mckenzie

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Re: Shetland Attack Pony
« Reply #31 on: January 02, 2008, 11:29:06 pm »
An article in The Canadian Caver #67 on Isla Madre de Dios mentions "the marriage betwen Auriga, a cave survey freeware for PDAs running under Palm OS, and Easytopo, an all-in-one topobox... Easytopo generates a laser ray to point towards the next survey station.  Then, pressing the one-touch button, length, azimuth and slope are sent automatically to Auriga, where you can see your actual progression in plan or elevation view."

He was getting fairly good results though using a tape and a rock,
I've recorded data on rocks before, having forgotten to bring a notebook.  Makes for a heavy tackle-bag by the end of the survey...

Offline menacer

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Re: Shetland Attack Pony
« Reply #32 on: January 08, 2008, 02:01:59 pm »
Psst.
I hear a batch may be ready for delivery by the end of next week...  :thumbsup:
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Offline menacer

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Shetland Attack Pony
« Reply #33 on: May 29, 2008, 08:52:22 am »
Phil gave me a handy tip for checking if your pony has been happily groomed fed and watered.
Find yourself a fixed to and from point, no where near any metal work and remove any wrist watches.

Take the same reading with pony faced up, 90 degrees left, upside down and 90 degrees right.
The readings should all be the same give or take a 2 degree error margin.
If they are wildly out its unlikely youll close any loops surveying...as discovered recently on a rods/bath survey trip on mendip.
Recalibrating it is relatively straight forward, the instructions are online on the shetlandattackpony.co.uk website.

As there are a few of us in mendip with Ponies im hoping to set up a permanent recallibration station (with 12 fixed stations of known compass clino) thing in the library at the Wessex...just need to ask the wonderful committee for permission ...  :kiss2:
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Offline Cap'n Chris

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Re: Shetland Attack Pony
« Reply #34 on: May 29, 2008, 09:02:10 am »
Stables at the Wessex? Whatever next?

Offline graham

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Re: Shetland Attack Pony
« Reply #35 on: May 29, 2008, 09:38:46 am »
Would a pony not be affected in some way by being surrounded by plumbing & electrical gubbins inside Upper Pitts?

And wouldn't the distances be a tad on the short side for good calibration shots?
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Offline menacer

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Re: Shetland Attack Pony
« Reply #36 on: May 29, 2008, 11:54:11 am »
Would a pony not be affected in some way by being surrounded by plumbing & electrical gubbins inside Upper Pitts?

And wouldn't the distances be a tad on the short side for good calibration shots?
No  :)

http://www.shetlandattackpony.co.uk/downloads/manual2.pdf
read the bit on how to calibrate...as long as there are no electrical wires or pipes running across the middle of say the library it shouldnt be a problem....
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Offline pete h

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Re: Shetland Attack Pony
« Reply #37 on: May 29, 2008, 08:12:59 pm »
Would a pony not be affected in some way by being surrounded by plumbing & electrical gubbins inside Upper Pitts?

And wouldn't the distances be a tad on the short side for good calibration shots?
No  :)

http://www.shetlandattackpony.co.uk/downloads/manual2.pdf
read the bit on how to calibrate...as long as there are no electrical wires or pipes running across the middle of say the library it shouldnt be a problem....

central heating pipes maybe above ceiling and most certain to be wires as the light works.   :idea:

Offline SamT

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Re: Shetland Attack Pony
« Reply #38 on: May 29, 2008, 08:25:49 pm »
surely your better off doing it outside somewhere  :coffee:

, prividing your not near any water mains - overhead cables, underground cables etc etc   ::)

Offline menacer

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Re: Shetland Attack Pony
« Reply #39 on: May 29, 2008, 08:38:24 pm »
So nobody's actually read the calibration method from the maker of the device then.....guys you only need to read the 1st 4 points and all your questions/thoughts/ponderings will be answered...
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Offline graham

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Re: Shetland Attack Pony
« Reply #40 on: May 29, 2008, 08:41:57 pm »
When a lot of survey work was going on in Wookey, some years back, Willie Stanton set up a calibration leg in the  car park - only to be told some time later that a bloody great conduit stuffed with magnetic ooh nasties went just underneath!

What this reminds me, however, is that calibration should be carried out both very close to the site being surveyed in both space and time.

Now, unless the Wexses intend re-surveying North Hill Swallet on a regular basis ...
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Offline graham

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Re: Shetland Attack Pony
« Reply #41 on: May 29, 2008, 08:50:35 pm »
So nobody's actually read the calibration method from the maker of the device then.....guys you only need to read the 1st 4 points and all your questions/thoughts/ponderings will be answered...

Aha, OK. There are two different things going on here. The calibration that Menacer is talking about will ensure that the instrument is recording consistently. The calibration that I, and I suspect others, am talking about is calibrating the instrument with respect to a known bearing. Given that the instrument is reading a magnetic bearing, the one form of calibration (Menacer's/the manual's) does not mean that the other form (mine/every magnetic instrument's) can be forgotten.
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Offline graham

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Re: Shetland Attack Pony
« Reply #42 on: June 26, 2008, 05:41:42 pm »
How accurate is a SAP.

OK, I have the data, recorded using a SAP.

I know the mag var on the day.

But what other correction is needed?

Or to put it another way:

How accurate is a Shetland Attack Pony?
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Offline menacer

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Re: Shetland Attack Pony
« Reply #43 on: June 26, 2008, 06:31:39 pm »
They are calibrated to a normal magnetic compass or clino.....is that what you mean.....(my pony says 100 degrees so does my tandem) so it depends on how accurate my compass clino is really...
The manual states tolerances of +/- 1 degree...

That small loop we did in sidcot down the lobster and up lobster pot bypass with an error of 0.61 gives it a fairly good field test, but mine in particular is reliant on the tandem I set it up with...as will be every individuals once they calibrate theirs after the first "factory setup" from Phil...
I did a manual pony test before and after use in sidcot and nothing changed.....(checked the left right up and downs)

Maybe email Phil at furbrain dot org dot uk to get "the info from the ponies mouth"

« Last Edit: June 26, 2008, 06:56:31 pm by menacer »
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Offline graham

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Re: Shetland Attack Pony
« Reply #44 on: June 26, 2008, 07:17:35 pm »
So your pony has the same systematic error as your tandem.

I wonder what it is ...
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Offline menacer

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Re: Shetland Attack Pony
« Reply #45 on: June 26, 2008, 07:42:02 pm »
My tandem is 1 degree different to the factory settings supplied on the pony.
The pony is accurate to +/- 1 degree.
My tandem could be spot on or it could be 2 degrees out.

Either way it would be consistent.

Im guessing the surface calibration thing against a fixed point(as done with normal compasses) would equally apply here.
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Offline graham

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Re: Shetland Attack Pony
« Reply #46 on: June 26, 2008, 08:12:27 pm »
Im guessing the surface calibration thing against a fixed point(as done with normal compasses) would equally apply here.


YES!!!
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Re: Shetland Attack Pony
« Reply #47 on: July 22, 2008, 07:09:33 pm »
Hi everybody,

I'm a caver from Barcelona (Catalonia), and I've recently received a new unit of the SAP, and now I would like to download the Windows Driver and the PonyTrainer software, but it looks like their website www.shetlandattackpony.co.uk  is down and Phil is bouncing the emails I sent him. Does anybody know an alternative place to download the software and driver?

Maybe Phil manages to put his website running in short, but I'm going to a caving expedition and we won't have internet connection available.

Thank's in advance,
Josep Guarro

Offline menacer

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Re: Shetland Attack Pony
« Reply #48 on: July 22, 2008, 08:48:19 pm »
I have a copy of the drivers i could mail you if you send me your email address..
Tried ringing phil but no answer  :'(
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Re: Shetland Attack Pony
« Reply #49 on: July 23, 2008, 08:56:30 am »
I have a copy of the drivers i could mail you if you send me your email address..
Tried ringing phil but no answer  :'(

Many Thank's! I've just sent you a PM.

Josep