Have a new street job in town with a lot of stuff in the way. There is a new line of 30" or so diameter fiberglass (or some type of composite, not steel) power poles set in concrete about every 100' on one side of the road. Thinking about putting stick-on targets on some of them as reference points to resection from, H & V. What's the best kind of targets to use? All the existing control is in the R/W and will be destroyed. Have DR on an S6, but would rather be able to shoot with EDM.
we've done ok with sokkia, small silver squares with fancy black crosshairs. you might want to prime the spot with a small blast of spray glue first
Reflexite tape works great. Use an office hole-punch to make your own. Comes in a variety of colors; been using it for years for close-range photogrammetry.
We are curently using the ones in the photo to monitor another partial collapse of a berth at Port Newark. Wok well when they stick.
I would cut squares of DOT reflective tape and stick them directly to the poles.
Search Ebay "Silver Reflective Tape" if link not working.
Reflective tape that has tiny retro-reflector prisms molded into the tape work best since they will return a signal or EDM pulse with an angle of incidence as little as 17º.
If you purchase the old-timey bicycle reflective tape, it will only return signals between 90º and about 45º.
Reflexite is the good stuff.
3M (Scotch) does make the good stuff also, but it's as expensive as Reflexite.
For sticky targets I have found that Leica brand have better prismatic quality that Sokkia.
A dab of liquid nails can do a lot to help seat the target.
The targets shown on page 3 and 4 of this catalog are quite useful as they can be faced in any direction:
http://www.tunneltrade.com/pdf/4980.pdf
They also have ones with glass so you can use target recognition if you like.
I think it is best to spend the extra money and get targets designed for surveying rather than fashioning targets from safety tape, may not always need the extra quality, but when you do I feel it pays off to have it.
I heard a rumor that these were going on sale on Monday.
Hi Cliff!
Thank you for sharing this very important information.
Regards.
Arnel
> Reflective tape that has tiny retro-reflector prisms molded into the tape work best since they will return a signal or EDM pulse with an angle of incidence as little as 17º.
>
> If you purchase the old-timey bicycle reflective tape, it will only return signals between 90º and about 45º.
>
> Reflexite is the good stuff.
>
> 3M (Scotch) does make the good stuff also, but it's as expensive as Reflexite.
