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What to take with you when Benchmarking


ArtMan

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I'm starting to realize that identifying and photographing benchmarks requires some extra tools. I'm just starting out to formulate my kit, and your needs may be different depending on the kind of station you are recovering and the part of the country you're in. That said, here's my list:

 

(a) GPS - actually, not really required. Most descriptions are adequate without reference to GPS, but it might help you navigate to the general area.

 

(:) Tape measure - often descriptions include distance from nearby landmarks. 50-100 feet would probably be idea, but even a normal household 12' model will be of help. (When all else fails, remember that for many people a good stride is about 3' or one meter. You can pace it off.)

 

© Long bladed screwdriver - preferably an old one, to poke the ground to discover benchmarks that have been grown over by vegetation

 

(d) Compass - locations are often given in terms of distance and direction (e.g., 12.5 feet south of the culvert)

 

(e) Pruning shears - to cut back vegetation grown over your benchmark.

 

(f) Gardener's gloves - for cleaning up the benchmark

 

(g) Small brush or wisk broom - to remove debris from benchmark area

 

(h) Water and rag - I wouldn't use anything stronger, but these things are meant to be out in the rain, so surely plain water can't hurt. Sometimes taking a photo when the water has only partly evaporated will make the stamping more visible.

 

That's my list with less than a week's experience in the Benchmark recovery business. I'd be happy for other suggestions to add to the kit.

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quote:
Originally posted by ArtMan:

(:) Tape measure - often descriptions include distance from nearby landmarks. 50-100 feet would probably be idea, but even a normal household 12' model will be of help. (When all else fails, remember that for many people a good stride is about 3' or one meter. You can pace it off.)


 

Why do you need a tape measure if you have a GPS?

 

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Why bring a tape measure (or a rangefinder)?

 

Maybe you have a $20,000 surveyor-quality GPS, but my $100 etrex normally gives me accuracy of 20' at best. Sometimes the easiest way of finding these things, which may be obscured by lawn or foliage, is to measure the distance to particular landmarks mentioned in the benchmark report. But if your GPS is good enough for you, who am I to argue? :-)

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Pacing can be very useful. With a little practice you can regularly get within 1-2 feet on a level surface over a distance of 100 feet or more. You can even learn to adjust the length or number of your paces so that it will work even on a slope. If you are outside the city, the 7.5' or 15' USGS topographic quadrangles, known as quad maps, should be at the top of your kit list. They can be ordered by lat/long or place name. An index for each state is usually available at good map stores and is often given out free to regular customers.

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All I bring is the printout of the description, an aerial photo, a USGS map, my digital camera, and my GPSr. I usually don't turn the GPSr on until after I've found the disk, since the coords are usually way off. I use the GPSr to get accurate coords to post in my log. Of course, I'm one of 'those people' who hunt caches GPSr-less most of the time, too.

 

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quote:
Originally posted by survey tech:

Pacing can be very useful. With a little practice you can regularly get within 1-2 feet on a level surface over a distance of 100 feet or more. [...].


With a rope between your ankles you can walk in very precise steps (do not fall over, takes some learning:-). Most people are big enough to make steps of 1 meter, so with a bit of calibration of the ropelength, pacing metrically precisely is easy.

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quote:
Originally posted by ArtMan:

Why bring a tape measure (or a rangefinder)?

 

Maybe you have a $20,000 surveyor-quality GPS, but my $100 etrex normally gives me accuracy of 20' at best. Sometimes the easiest way of finding these things, which may be obscured by lawn or foliage, is to measure the distance to particular landmarks mentioned in the benchmark report. But if your GPS is good enough for you, who am I to argue? :-)


 

Well, my thought is that most of the factors that affect accuracy change slowly over time, so even if your GPS is off by 20 feet to the southwest, it will consistently be off by about 20 feet to the southwest over the next several minutes. That means that as long as it doesn't take you too long to measure your 27' line, you can probably get a lot more precision than you think, and a lot easier than lugging a 100' tape around.

 

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Prof. Y. L.

A very original idea, I have yet to see anyone strap their ankles together in order to pace more accurately. I fear this could prove to be suicidal, should one slip or trip while on a slope. With regard to using a 100' tape, a cheap light weight cloth or fiberglass tape works just as well as a metal tape, so carrying one along is not much of a burden.

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...a thin piece of paper and a crayon to make a "rubbing" of the marker disk? That might make an interesting souvenier of the find and you could also cut it out and past it into a scrapbook later if you wanted to. (Black paper and a gold, silver or bronze crayon would really make an interesting rubbing, I think!) Add a photo of the surrounding area, and a note on the date and time you found it on the same page and you would have a cool show and tell item to bring to geocaching events.

 

Just a thought.

 

Teresa (Adovbs)

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quote:
Originally posted by ArtMan:

I'm starting to realize that identifying and photographing benchmarks requires some extra tools.


 

Add a yellow crayon to your list along with digital camera to take photos. The NGS site suggests highlighting the markings with a yellow crayon so they are more legible in photos - if you want to submit photos to them.

 

Now what to do with the rest of those colour crayons!

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A few years ago, I calibrated my pace and have since found it a good way to measure.

 

In an office environment (hallway, preferably), notice the ceiling tiles. Often they are the ones that are 2 feet x 4 feet. Also, most floor tile is 1 foot square (or 9-inch if it's really old). Pace for 50-100 feet and count tiles and you won't have to bother with measuring tapes.

 

I have a particular "measuring pace" that I know will give me good accuracy. Plenty good enough for the 100 feet or less in benchmark finding.

 

Once you've calibrated yourself, you're ready for benchmark finding and other uses too.

 

So, I'd add my calculator watch to the things to bring - I divide the number of feet stated in the description by my calibration (2.54 feet per pace). Same as cm / inch - how about that! Cellphones have calculators in them also.

 

Oh yeah, bring your cell phone in case something happens to you or your car!

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I got one of those folding army shovels (an entrenching tool I believe) for my birthday. Yeah, weird family I have. Anyway, it's totally perfect for finding things. A lot of BMs around here are on culvert walls, and have silted over. Careful use of the shovel will remove the dirt in a hurry and not wreck the disk/bolt/whatever. It'll also dig up other things.... My only issue was at the following triangulation station (didn't find the disk... dug a huge hole... I think it's missing, but don't know for sure...)

check it out, and think about me, with my shovel...

 http://www.geocaching.com/mark/details.asp?PID=NB1989 
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Its a bit surprising you could not find this one - unless the fence has been replaced. I assume you found some of the reference points or headstones mentioned and measured the distances given from them to determine where to dig. Its always a good idea to measure out 3 or 4 of the diatances given before digging, instead of just 1 or 2. If 3 or more distances do not intersect at the same spot, then you know something has changed and you cannot be sure where to dig. Remember you must tape the distances level, not along the slope - this can make quite a difference if you are on ground that slopes several feet.

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Instead of printing out all of the benchmark pages on paper...I like to cut and paste the info for each Benchmark into a Palm Pilot Memo file. This is faster than you think, plus I keep all the geochaches in the area in there as well until I visit them and then delete them. Saves a lot of paper and inkjet cartridges. Now If we can only get someone to design a dowload function on the website so we can click a button and download the benchmark info automatically into a Palm memo...

Oh well, just dreamin'

 

Havin' fun lookin for them all

-Uncle Alaska-

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quote:
Originally posted by headmj:

I always use the GPS for Horizontal stations because their coordinates are every accurate. Its the vertical stations that tend to be scaled to within 6 seconds


True. But I still prefer to hunt GPS-less. The vast majority of the benchmarks in my neck of the woods are marked on standard USGS topo maps. It's easy enough to use tha map to locate the marks. I just enjoy the extra challenge.

 

As for pace-counting, with a bit of practice, most people can learn to pace-count within a few feet. Mark off a precise distance, or use a high school track. Pace off the distance several times, on different days, and find out what your average pace is. Walk as naturally as possible. You'd be surprised how consistent you can be. I'm lucky in that my pace (two steps) is exactly 6 feet, which makes the math a lot easier than if my pace were something like 5 feet 10 1/2 inches.

 

25021_1200.gif

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>>(h) Water and rag - I wouldn't use anything stronger, but these things are meant to be out in the rain, so surely plain water can't hurt. Sometimes taking a photo when the water has only partly evaporated will make the stamping more visible.

 

I had to resort to spit and my sock because I forgot my water bottle and rag. I assumed a hop, skip, and a jump, only to find huge thorn bushes icon_frown.gif Once I was in, I was not going back out to get some water!

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