Well, it took all summer to figure out that there was an easier way to site a prism target through thick woods, than stringing flagging all over the place at intervals along the line and walking back and forth until the line was clear enough for the EDM to work....
Grabbed my LED stroboscopic head lamp I use on my mountain bike. Looking straight at the thing from even 15 or 20 feet a way is blinding. It has a lens that focuses the beam to about 10 degrees or so...fine to roughly aim along the line. Even in dense underbrush, this thing COOKS!
Now that's what I call "Good Thinking". In the old days, we used mirrors, to reflect the sun, so the i-man could find us.
N
Any kind of flashing light works great. Well; unless you're using a robot...:totalstation::stakeout:
Doesn't take much. Human eye can pick out a candle flame at 30 miles, or so I'm told. Maybe 10 in my case.
I think it was SECO that used to make a strobe prism for use at night or in dark woods. I think it had the back corner of the glass ground off, with small light there to light up the glass. I don't recall it working so great. I'm sure it was no match for today's LEDs.
I picked up an amber safety strobe LED I velcro to the top of the active prism to find myself with the video in the thick. Only works when I set it to shine continuously as the strobe is nearly always out of sync with the video's frame rate.
You're using a robot, yes? Solo?
I'm solo, but no robot. I-man, Prism-man (at least when my wife's not with me), bushwhacker; I do it all.
No video needed; just eyeballs.
I've had to watch the rodman all the way to their setup at times. Blink and they have disappeared....and sometimes, they are simply behind a tree and can't see me either....
😉
We used those a few years in an underground mine. We found it was easier just to use a flashlight pointed at it from underneath the tripod.
We used to use mirrors. Of course you had to flash it when someone is looking but it works great.
Here's a little trick for running a random traverse through woods that might work well for what you're doing where your doing it rfc. For your traverse points, cut a small diameter tree (4-6" dia.) off about 3.5'-4' off the ground. Take a little flagging and either thread a nail through it or wrap it and set it in the stump leaving it sticking up 2-3" and use that for your traverse point setting up your instrument over the nail. Bit more tricky setting up because of the height. Then as you traverse on up to the next station, you have a ready made back sight and no need to go back to pick it up to move ahead. Downside, no distance back sight check, just line. If you're doing this solo, spares you having to lug a second tripod around for your back sights. If you have a second person at the gun to give you line on the back sight, you can nail a cross arm lath to a tree up high and have the instrument operator give you line to mark the lath with a ^ using a sharpie for the back sight. Another back sight involves using a 4' lath and a plumb bob to set a flagged nail in the top of the lath over your trav point on the ground. Not recommended if there's a strong wind blowing. Idea being no need to keep going back to move your back sight ahead. I miss long traverses through the forest. (Sigh).
Carry on.
Depends how client feels about his trees.
Yes it probably does, but since my wife is the "client", and we both agree there are so many #$@%@# trees we could probably cut half of them down and still have plenty left (and a lot of firewood), that wouldn't be a problem.
Now, just what would the centering error be on a mag nail in the top of a 4' poplar stump be, over time, or at least for 5 or 10 years until it either rots or grows sprouts around the base? I can't imagine it'd move much. I like the idea. Wouldn't need a metal detector to find it either.
Using good judgment goes without saying.
Williwaw:
You just gave me an idea:
If I occasionally needed distance, (which I would, if this became a station in my control network I'd use again),I could just drop a prism on a tribrach right on top of the stump over the nail (which I could drive nearly flush). At other times, I could just use these stumps as convenient back sights. Thanks for the ideas.