Tips for DTM shots - Solo - With Refletorless - On Pavement

No way you can hire a young interested kid to give you a hand for a few hours?

I was doing that sort of stuff from age 13 on.
I'm thinking that is how most of us got exposed to surveying.
In my case, there were several surveyors that would "share" my services when times were too slow to have full time help.

I have to believe I made them more money than they were paying me.

Dots candies. Like a cone shaped gummy bear. Might get bit gooey if pavement's hot, but otherwise work pretty good. I like the pineapple, but the cherry flavor's not bad either. Don't care much for the green so if they get run over, no big loss.

years ago someone mentioned shaving cream ... evidently it last a little longer than I thought ... the white makes a good target and if anyone runs it over ... so what.

For me, I once bought a bunch of those 4" tall "traffic" cones from DollarTree and put some pieces of reflective tape at about 3-1/2"(almost the top), around.

I walked up the rod putting them down every 7-8 steps ... shot them, then picked them up in order and place them back down again ... I've done miles of road like this.

I've also used small blocks of wood(again, with reflective tape), but I like the idea of the reflective tape being slightly higher ... hence, the small cones.

You've got to make sure the striping on the road doesn't interfere with the distances.

Little blocks of wood cut from a 1" x 2" and painted pink. The pink is essential for spotting the blocks on pavement. Shoot about 0.02' up from the base.

Except for it being a waste of good chocolate Hershey's Kisses would work pretty good.

"remote control vehicle"

One laser scanner operator I know uses talc or baby powder in order to get a return off asphalt.

The last job I did with my reflectorless instrument required just this. The kicker was that many of the shots were on pavement that had occasional traffic. I bought a box of 100 - 3/16" x 1-1/4" fender washers and stuck tabs cut from 2" reflective tape to them. The tape was 2" wide and I cut 1/2" wide strips of it to make a 1/2" x 2" tab. Folded in half, with 1/2" flanges stuck to the washer and a double-sided 1/2" target sticking up, it worked great. If I had to make them over again, I'd probably use red tape instead of white to aid visibility. The vertical accuracy was superb.

Do you mean you need something to aim to shoot on the asphalt to get it reflected?

Normally I would get chalk paint to spray on the ground. Rain will wash it away so no worries on it being unsightly.

It definitely works! One of the first things we found out when trying to get returns on black objects.

You need a vertical target on a distant surface to get an accurate return if you have a flat angle. Otherwise you will get a result, but not an accurate one.

> You need a vertical target on a distant surface to get an accurate return if you have a flat angle. Otherwise you will get a result, but not an accurate one.

http://www.gardenstatehwy.com/catalog_category.aspx?cat_id=77

😀 😀

Be kind of fun to mount a 360 active prism to a rc car. Drive the little bugger around while robot takes shots on it. Or would that qualify as goofing off on the job. 😀

2:42 onwards:

Decent tracking, eh?

Impressive. No 'rc' unit in the "mobility-assisted" tracking, either.

Just need a time dependent side-shot routine (i.e. store shot every x.x seconds) and a good measure up on the 2-stroke.

That video could be a good add-in to the thread on PS (v. QS) tracking that someone posted the other day.

Thanks so much guys for the great tips. I think I am going to pick up some wooden craft blocks at Hobby Lobby. Paint them white or fluorescent. and stick on some quarter sized, self adhesive, .22 cal target stickers to them for a consistent aiming point. This is a vacant parking lot. In traffic, I love the idea of some tape and washer tents that could be run over with no ill effects.

I also thought of the little "Tent" or micro sandwich board signs you get at some restaurants for them to bring your order out to you. About the size of a folded playing card. Kinda like the signs they use in forensic photography over spent shells and such.

Thanks again guys for all the suggestions.

CB

> In traffic, I love the idea of some tape and washer tents that could be run over with no ill effects.

I probably should have posted a photo of the washers with the reflective tape tabs, but better late than never:

Since the tab is only a 0.04' x 0.04' target, it isn't difficult at all to point at the center of the target with an uncertainty of < 0.01 ft. The other advantage to reflective tape, of course, is you can easily see the return flash from the laser and know you've hit the target.

Kent,

That's brilliant. Thanks for sharing. I'll have to make some of these, along with some of the craft stick targets. It never hurts to have an assortment of ways to tackle a job!

Thanks to everyone that shared their methods.

Jimmy

I hate to ask a stupid question, but if you have access to place the targets then why can't you just use a rod and prism?

I have used the chalk paint for laying out a grid and then running levels for airport verification work. The stuff is great, it sticks around for about a week.

Good luck