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Geodetic Survey Markers in Canada

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I downloaded from the Nrcan spatial reference system database (free but need to register) the marker locations for my local NTS map sheet (040J16, Sarnia, Ontario) and was surprised to get 686 locations. Names vary from just numbers to more intriguing ones (e.g. Vista, copper plaque, US Army (what were they doing here!?), Weed, Wave etc). A condition code is listed for many of them but I don't have the key. I've found a few so far and they vary from standard survey markers to more impressive monuments. In other cases there is nothing obvious in the vicinity. Would appreciate any experience anyone has. Should I expect to find something at all locations? Do the names/numbers give a clue as to what might be found? Anyone decoded the condition and other codes? What kind of accuracy should I expect (locations are in Deg Min Sec format and one at least (a very old one) appeared to be a couple of seconds off position.

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This post has really gotten my own curiosity going now....

 

I'd be curious to see where the reference points are for my own area. Could you by any chance post the link for the database that you mentioned? I think it might be fun to hunt for some Canadian Benchmarks.

 

Gord.

Team Bradinn

 

"When I was a young man, I journeyed to the West to find myself......it turns out I had the wrong coordinates."

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http://www.geod.nrcan.gc.ca/index_e/products_e/online_data_e/online_data_e.html

 

As you'll see it's free but does require registration - the temporary username and password comes quickly. Once on it's pretty straightforward and there are on-line help and examples (putting in the NTS Map Number and downloading as a text file worked best for me, the text file loads into Excel and can be parsed into columns and then sorted any way you want). Happy hunting. Let me know what you find.

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The Canadian Base Network geocache as been around since March. You download monument descriptions from the Geodetic Survey of Canada web site, which does not require a login. These are first order monuments that provide sub-centimere accuracy and are all in positions that are specifically chosen for their unobscured views of the sky.

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On my old topo maps there are noted, "Triangulation Stations". For the most part, these appear to have been placed on areas of high elevation - and can make good destinations for hikes/drives because of this. That said, I've only found one, very near a Geocache at N43 25 24.8 W79 52 39.8, that has any evidence of even existing! Here are the concrete foundations of what appears to have been a three-legged structure (tower), but the tower, of course is conspicuous by its absence.

Is there an official database of these, like there is for the benchmarks or are they just arbitrary locations chosen for a good place to set up a survey?

 

As for the regular benchmarks, these don't make for a very satisfying catch (cache?) for me as they are found everywhere. The ones near my place are in exciting places like on sidewalks and curbs. As mentioned before, the Canadian Base Network are more interesting as they've been chosen for their excellent vantage points.

 

When planning a bike ride, I tried to find a couple of the more remote, and elderly, benchmarks in my area. I found it amusing that they had last been inspected in 1910!! Nonetheless, I punched the coordinates into my GPS and plotted my bike route by them with great expectations. Two problems occurred with this hunt.

 

(1)The coordinates were out of whack.

I guess some advances in location technology have occurred over the last 90 years. The description of the locations are quite concise, but when plotting in the coordinates they are way off. Interesting to note on the Garmin Enhanced Basemap they are much closer to their actual, or alleged, location. I think its apparent Garmin used some very vintage maps to design their Enhanced Base Map software. Actually, this is patently obvious by the presence of the old Toronto Grey and Bruce railway which is still shown. I think this one was decommissioned before WWII !!

(2) There was nothing to be found.

In one case the benchmark was described as a small metal rod extending from a culvert. I couldn't even find the culvert so I'm guessing it is long gone or well buried!

 

I have enough trouble finding some Geocaches so I'd better stick with hunting those!

 

Cheers! Coupar-Angus

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...what (if any) periodic confirmation is done with Canadian benchmarks. A Herculean task, to say the least, but surely the GC makes *some* effort to determine that benchmarks being shown on new topo editions are still valid (both in location and elevation).

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quote:
Originally posted by Cache Canucks:

...what (if any) periodic confirmation is done with Canadian benchmarks. A Herculean task, to say the least, but surely the GC makes *some* effort to determine that benchmarks being shown on new topo editions are still valid (both in location and elevation).


 

I've done some inspections of benchmarks (two only, actually) and sent in inspection reports. The report in one case was updated to the current year.

 

I just sent in pictures but they haven't been added yet.

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