Anyone had any experience of this sort of kit?

http://www.aichi-mi.com/old_pages/2_NEWS/underground%20mall%20navigation.pdf 

http://japantechniche.com/2008/11/12/underground-navigation-system-by-aichi-steel-corp-ami602n/ 

Inertial Guidance Navigation systems such as this would be used for are technically very difficult to implement.

I recently looked at a similar chip from an US vendor and is was in the US$2500.00 range, not saying this would be, but might be an indicator.

IGN is used for missiles and backup navigation for military systems and I would imagine for some civilian stuff as well should the whole of the GPS network go down.

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Thanks Mr Mike. I did suspect it would be too expensive for a one off project.
Never mind, back to the drawing board.

but if it could be done..... it would almost be like the mapping spheres in Prometheus

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I want it now. 😉

Got one. 😉

I have been using such a unit for nearly 3 years now and got some usable results so far. It's certainly not as easy as it sounds and some data needed a lot of interpreting. I'd prefer to call the results a scaled sketch rather than a survey.

Go on then, spill some more beans....

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Contains a low field magnetic flux thingummybob as well as an inertial doodad. I wonder how well it performs in iron mines?

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I' using a DRM4000 demonstration unit with some success.

Any magnetic interference will cause a deviation. Best to stay away from any steel or iron.

On surface GPS helps to increase accuracy, but the device works on a user defined 'standard' step underground. This does cause some problems when climbing ladders as this will be interpreted as horizontal movement.The height is still ok due to the altimeter.

You can set a marker.

Otherwise the position is within 1 or 2 % of the distance travelled. Surface will have lat/long, whereas underground is limited to a local east/north.

I'd call the plot a scaled sketch. It's a quick way for a 'survey' if you know and accept the limits.

Header:
HLOG0;n;ses;time;east;north;lon;lat;hdg;alt;stepsz;bofs;glon;glat;gEPE;gqual;steps;KGRSYAHT;dVolt;mField;sat;mk

Any magnetic interference will cause a deviation. Best to stay away from any steel or iron.

That's my project out then as it involves mostly corrugated steel culverts with odd branches. Back to tape, lamp and borroewd miners dial by the looks of it.

US$625.00 from Digikey.

It is interesting that it suffers from magnetic interference, and as Morlock says that can cause problems for use in mines - lots of iron and steel.

You would have thought that there was a way round it. A normal manual compass can cope with it, providing you are around 0.5m away, where as digital compasses are much more sensitive to it.

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Iron/steel ships use magnets to compensate but suspect that's a non starter for our purposes. "Kelvin’s Balls" also look a touch on the heavy side. :lol:

http://www.acecrc.sipex.aq/access/page/?page=afcfbb2e-b886-102a-8ea7-0019b9ea7c60 

We've used a bog-standard Silva compass to do back of a fag packet surveys in ironstone before. If the stone did cause any deflection it wasn't immediately obvious, certainly not for the degree of accuracy we were concerned with.

Any reason not to use DistoX as is favoured by cavers who tend to like their surveys to be highly accurate?

I'm still trying to get my DistoX built - just lazy about it.

However speaking recently with the designer of it, that also from what he said could suffer from being affected by metal. He told me they started a survey in a cave entrance, only to be really confused by the results. Turned out a dumped metal bed frame in the entrance was causing errors at 3m away.

When he told me this, I started to have doubts about the use of the DistoX in mines.

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We've used a bog-standard Silva compass to do back of a fag packet surveys in ironstone before. If the stone did cause any deflection it wasn't immediately obvious, certainly not for the degree of accuracy we were concerned with.

Any reason not to use DistoX as is favoured by cavers who tend to like their surveys to be highly accurate?

Hi there, that's what I used (Silva Compass) in a underground survey I did some years ago in an old tunnel that had a large iron lode traversing it, the brief was to locate old plugged and filled shaft locations on surface, the tunnel is crooked in parts ie: not a straight run.
I crawled in with a suveyors tape, an offset Silva a couple of bits of paper and a pencil.
The measurements, bearings were taken of the shafts within the tunnel then walked out on surface replicating the same and within a couple of yards or so the shaft locations were spot on, I am not saying that the iron lode did not have any effect on accuracy but it was much less than I thought it would be.

Lozz.

There seems to be a big difference between electronic and conventional compasses. I've been using German dials (compass & clino suspended from a string) for well over 20 years now and the general rule was anything more than 1.5 m away and the size of a tub doesn't really matter much. Digital devices seem to be a lot more sensitive.

During my first tests of the DRM4000 a lamproom magnet some 5 m away and behind a wall still caused interference.
None of my oldfashioned instruments showed any visible reaction.
During current surveys in a slate mine with the device rails or pipes will show as well as parked tubs or flatbeds. The SAP has the same problem with rails about 1.0 m away. The problem with the DRM4000 possibly is that you can't move away from the interference but have to walk past. With traditional instruments I'd check for anything messing up my survey and try to stay clear but that is not always possible with a tracking device.

The SAP has the same problem with rails about 1.0 m away. .

Ummm, if you say that the SAP has compass issues due to metal, then I would imagine the DistoX will have issues down mines. Maybe I need to sell the kit on ukcaving?

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Don't even think about selling it.

But you certainly need to know the limits of your surveying instruments and adapt how you work with them according to the environment.

Thanks Mr Mike. I did suspect it would be too expensive for a one off project.
Never mind, back to the drawing board.

If it's just the chip you want you could always try one of these at about $2 US

http://www.eetimes.com/document.asp?doc_id=1259317 

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Thanks Mr Mike. I did suspect it would be too expensive for a one off project.
Never mind, back to the drawing board.

If it's just the chip you want you could always try one of these at about $2 US

http://www.eetimes.com/document.asp?doc_id=1259317 

If only it was that simple !

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