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J Peterman
       
location:
Victoria B.C.
I'm going hunting for mysteries, cover me.
 |  | GPS Underground/Mapping Tunnels?
< on 12/24/2005 9:53 PM >
|  | | | Does anyone know if GPS work underground, in storm drains? I'm looking to somehow map out underground tunnels I've come across, then super-impose those onto streetmaps on the computer. That way I could have detailed coordinates for tunnels and entrances.
Though I'm skeptic that GPS would work 10-20 feet underground (solid brick, ground, and cement)
Any ideas?
I'm going hunting for mysteries, cover me. |
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Sinister Crayon
location:
Colorado
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 1 on 12/24/2005 9:59 PM >
| | | | If you climb up a manhole and hold at as close to the little hole as possible or if you hold it out by a gutterbox or something it might work. The GPS has to connect with multiple satellites so I am doubting it will work in any part of the drain.
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HillbillyHorus
location:
Charlottesville Virginia
Gender: Male
Im in ur government, killin ur d00dz
| |  | Re: GPS Underground/Mapping Tunnels?
<Reply # 2 on 12/24/2005 10:02 PM >
| | | | That's actually a very intriguing idea. I'm not very familiar with GPS systems, but all my attempts at mapping drains have been failures, mostly because compasses don't work underground. Like I said, I don't know how GPS works, but I suppose you could always stick the antennae (or whatever it uses) out of a manhole-hole or grate. Is GPS a continuous mapping system (like it maps as you go), or is it point-to-point (like you turn it on at different points and it connects the line)?
You can't fall off a mountain. |
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Xanadu
location:
Las Vegas NV
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 3 on 12/24/2005 10:03 PM >
| | | | It wont work, it has to have clear reception to at leaste three satellite (I think) for it too work properly.I mean you can try, does it have a signal meter? I would assume if you bring a XM radio down there and dont get no reception the same would go for the gps than.
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http://www.geoconn...article.asp?ID=753
"GPS doesn’t work underground"
Compasses dont work under ground? I find that hard to believe.
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Edit:Added link
[last edit 12/24/2005 10:08 PM by Xanadu - edited 1 times]
"Hey Fat Dave. <--Period" |
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HillbillyHorus
location:
Charlottesville Virginia
Gender: Male
Im in ur government, killin ur d00dz
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 4 on 12/24/2005 10:07 PM >
| | | | Posted by Crazydeep74
It wont work, it has to have clear reception to at leaste three satellite (I think) for it too work properly.I mean you can try, does it have a signal meter? I would assume if you bring a XM radio down there and dont get no reception the same would go for the gps than.
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I actually have played normal radio in a drain before, but not XM 
I just stuck the antennae out of a gutterbox. And it was a crank-radio too.
You can't fall off a mountain. |
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Xanadu
location:
Las Vegas NV
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 5 on 12/24/2005 10:09 PM >
| | | | Well a normal radio would, you have to remember that XM has to have "line of sight" with the satellite, same goes for GPS.
"Hey Fat Dave. <--Period" |
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J Peterman
location:
Victoria B.C.
I'm going hunting for mysteries, cover me.
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 6 on 12/24/2005 10:20 PM >
| | | | GPS is continuously mapping your path, but I think your right it needs to line up with 3 satellites.
It is a real pain to go up every manhole to stick an antenna up and wait for the GPS to lock on.
Are you sure about the compass thing? I would think that they do work underground. Even so I wish I knew how to use one proficiently. Any other ideas?
I'm going hunting for mysteries, cover me. |
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Xanadu
location:
Las Vegas NV
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 7 on 12/24/2005 10:39 PM >
|  | | | Read the link I posted, it has some information. I can see how using a compass can be annoying, but its prolly your only way.
"Hey Fat Dave. <--Period" |
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Glass
location:
Chicago
as one does
| |  | Re: GPS Underground/Mapping Tunnels?
<Reply # 8 on 12/25/2005 6:08 AM >
| | | | GPS doesn't work underground... no matter how shallow.
You won't even get a trace signal through a manhole either: I tried it Monday & GPS is worthless underground.
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HillbillyHorus
location:
Charlottesville Virginia
Gender: Male
Im in ur government, killin ur d00dz
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 9 on 12/25/2005 12:05 PM >
| | | | Posted by J Peterman
Are you sure about the compass thing? I would think that they do work underground. Even so I wish I knew how to use one proficiently. Any other ideas?
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Yep. There was a thread about it on the drainer's board, and I've tried it my self. The needle goes crazy. I don't think it has as much to do with the fact you're underground, as much as that there's big poles of metal holding up the tunnel you're in.
You can't fall off a mountain. |
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Glass
location:
Chicago
as one does
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 10 on 12/25/2005 5:42 PM >
| | | | Also a lot of drains run near utility tunnels containing communications, high voltage, and other electrical equipment that would likely confuse the needle if the needle's plane is the same as the leaked magnetic field (ie horizontal).
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J Peterman
location:
Victoria B.C.
I'm going hunting for mysteries, cover me.
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 11 on 12/25/2005 7:08 PM >
| | | | So what should I do, what are some other methods of mapping tunnels underground. Its important and obviously a pencil and paper does me little good. What do you think about climbing up to each manhole along the route and putting a little red spray painted rock or some marker like leave a pencil there. Then I could walk the route above ground and mark down on a piece of paper where each manhole was...then make a map. A little ridiculous?
I'm going hunting for mysteries, cover me. |
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Xanadu
location:
Las Vegas NV
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 12 on 12/25/2005 8:23 PM >
| | | | Posted by J Peterman
So what should I do, what are some other methods of mapping tunnels underground. Its important and obviously a pencil and paper does me little good. What do you think about climbing up to each manhole along the route and putting a little red spray painted rock or some marker like leave a pencil there. Then I could walk the route above ground and mark down on a piece of paper where each manhole was...then make a map. A little ridiculous?
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Actually thats what I was gonna recomend. Try it.
"Hey Fat Dave. <--Period" |
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CyberShoe
location:
Directly above the centre of the earth
Gender: Male
So what if I overuse ellipses...
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 13 on 12/25/2005 8:40 PM >
| | | | There's also dead-reckoning, if you have some way of reasonably accurately measuring distances and angles. A cheap theodolite can be made from a couple of protractors and a tripod, and some sort of sighting device. A Rolatape, or laser measuring device can give you the distance information. Then you just keep track of your distance travelled, and measure angles wherever you turn. When you get back home, you can plot that information on a map.
I don't know how well this would work underground, but I don't see why it wouldn't be feasible.
- CyberShoe |
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HillbillyHorus
location:
Charlottesville Virginia
Gender: Male
Im in ur government, killin ur d00dz
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 14 on 12/25/2005 9:37 PM >
| | | | Posted by J Peterman
So what should I do, what are some other methods of mapping tunnels underground. Its important and obviously a pencil and paper does me little good. What do you think about climbing up to each manhole along the route and putting a little red spray painted rock or some marker like leave a pencil there. Then I could walk the route above ground and mark down on a piece of paper where each manhole was...then make a map. A little ridiculous?
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I've done something similar, but it wasn't to map the drain. I drew with redmarker in each manhole-shaft that I knew was safe to open.
You can't fall off a mountain. |
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wooble
location:
Surrey, UK
Gender: Male
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 15 on 12/25/2005 10:30 PM >
| | | | well, to trace the track of a tunnel, you could plot a few known points on a map (e.g. infall/outfall, accessible/marked manholes) and measure distances and the rough angle of any bends. between known points. Google Earth is handy for marking points like that and working out tracks. You wouldn't need anything more complicated than a compass and a trundle wheel (or you could measure your pace and pace it out).
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Glass
location:
Chicago
as one does
| | | Re: GPS Underground/Mapping Tunnels?
<Reply # 16 on 12/26/2005 7:27 AM >
| | | | If I was going to do the same project that you're undertaking (and I promise that would never happen) I would use a paper and pencil to guesstimate the route underground, with notes make to manhole location, then I'd take the map above ground and walk where I thought it went with a GPS (if available) and trace the lines between manholes above ground. That should be accurate enough for any map.
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|
ofberenonehand
location:
Minn-e-snow-ta
"Where now is Boromir the Fair? He tarries and I grieve."
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 17 on 12/26/2005 9:16 PM >
| | | | The best way is probably just to measure the angle of turns and then distance before the next turn (counting steps, tape measure, laser device, etc. You can measure depth with a laser measure or by counting rungs.
It can be helpful to spot landmarks through a manhole. If you get the GPS out of the cover it should work. I've been thinking about getting a palm pilot version. Some of them have remote antennas which could fit through the small holes in manhole covers. GPS needs line of sight connection.
"That's What Government Is For; To Get In A Man's Way" -Mal |
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pyro
location:
Toronto
Gender: Male
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 18 on 12/26/2005 10:31 PM >
| | | | For counting steps, each step is appoximately 50 cm. You could try that for rough distance. With conjunction with a protractor and google earth that could work.
"[emo kids] are like homeless people with thier hand out only its pitty they want and not money." -boutdatlonestar |
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J Peterman
location:
Victoria B.C.
I'm going hunting for mysteries, cover me.
| | Re: GPS Underground/Mapping Tunnels?
<Reply # 19 on 12/26/2005 11:25 PM >
| | | | i just downloaded G. Earth, it doesnt have an underground layer does it? It wont display things under street level as a layer option?
I'm going hunting for mysteries, cover me. |
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