I've used them on bridge monitoring projects. Set your control targets (at least 3)at 0 offset on solid, permanent objects (guide rail posts, buildings, fence posts, etc.. At the same setup, set monitoring targets on the structure. (I've found that rubbing in a small dab of rubber cement into the concrete prior to sticking the target makes it rock solid) You can return to the site and resect yourself in and take measurements without use of a prism pole. Resection residuals are usually .005'. Range of my Nikon 520 to reflective targets 2"x2" was about 600'. I used some cheap reflective tape that I found on EBAY and it worked out well.
Thanks everyone !
Acquire samples of each and test yourself with a digital camera & flash. Shouldn't take more than an hour. Proof is in the pudding.
I learned a neat trick
:good: :stakeout: :good:
I set 37 of these targets on a 3/4 mile construction project, while I was checking the existing control. It didn't take that much more time. I wasn't able to get permanent ink to stick, but I was able to write the number next to it, most of the time. I've been thinking about sticking a small piece of write in the rain paper up with the sticker to write the number on, but haven't tried it yet.
The little dab of airplane glue sounds like a good idea too. A clean surface helps as well. A little sandpaper on a creosote post helps and I'll bet that airplane glue would make it even better.
No need to set up a back sight or look for control; just set up your robot; shoot 3 of the targets and stake out to a 4th. It turns right to it and was usually perfect. If you look throught the gun you might see a hundredth or 2.
I always took a shot with my prism pole too; usually on one of the last hubs I'd set and fudge the rod up and down until I got a perfect elevation. I always made a check shot before I picked up too.
They were putting in a new storm drain, water line, and curb gutter and sidewalk, along an existing 4 lane divided highway with a lot of traffic. They would close a lane every day, and then open it up at night.
I believe that in the not to distant future; that this will be the way costruction projects are set up. Except that you will be providing the client with 3d data and he is doing the resecting and grading, laying pipe, building formwork, everything he used to ask for hubs for.
All of the equipment is become so user freindly, why do you think we have so many button pushers? Because it's easy....
All the client needs is accurate data, precision control and a little gental guidence to save him time and money and you get to save a ton of liability.B-)
But then again, I could be wrong.......:-S
Radar
PS-Walter-I mailed you some targets today. Brad told me he got his today, so you should get yours early next week.
Firstly, sorry for the thread hijack. Thank you Radar and Sir Veysalot for your responses, very helpful. Thanks in advance for the targets, I'll keep an eye out for them.
A couple questions.
We run Trimble S6 instruments, when setting these targets and later resectioning to them, would I use the reflectorless (DR) or a custom prism with a 0 offset?
What limitations are there to the sight angle? Do I want to be as close to right angles to the targets? I believe Cliff is referring to this above. Cliff, could you please expand on your digital camera test?
Thanks.
As I said in an earlier thread, the scaly ones will return a distance just like a prism, except for the range, my S6 will lock onto them. However, I would never use the locked on position as it will float around. Turn off auto lock and sight in with the scope and read. The other ones Radar sent me had more of a metal flake look to them. I believe the S6 would read them if you were close, otherwise had to use DR mode.
I tried to set mine so I would be looking at them pretty close to 90 degrees. They are on some new 2' dia. composite poles set alongside a street project. I put 2 on some of the poles so I could use them from either direction.
Thank you!
