what do you guys think the fastest speed is acceptable for Auto topo. If it's set to 25 intervals. I will doing this with a topcon hiper II and carlson attached to the rear of the truck for topo of a 6 lane road . I dare not put the guys in the road for this.hoping to roll about 20 miles an hour so not to bounce . Anyone do this in roads.
I did this with a robotic total station on a landfill closure survey. It worked very well.
My software had the ability to specify distances between shots rather than a timed interval. I believe I set it to 50' and simply drove slowly. I then staked out enough of the shots to have a check.
It would work very well for elevations (as good at least as RTK), but I am unsure how you would determine that you are actually following a horizontal feature. It should be easy enough to have redundant measurements as well.
I would suggest a trial test on a low traffic residential street. That would be better than any opinion here.
Using RTK data for flat road terrain would result in spike data. This is due to the error itself from the RTK unit which is about 0.04 m or so. Don't believe your spec sheet if it says it isless than 1 cm. There are other factors at play in the real world.This is not noticeable for raw land terrain but would be noticeable when compared to total station data or level data. Not sure ifthis error is negligible for your purpose.
I am still thinking this out , not sure if the truck bounce will make this useless , probably just shoot it with robot Sunday at the crack of dawn , with the prism pole wheel.
I have taken probably hundreds of thousands of shots with my S6 in auto collect mode with no issues. Whether on road or off, I like to keep my speed well below 10 mph just to be on the safe side, to avoid bumps and a possible data lag from higher speeds.
We use ATV mounted Trimble units for some types of topographic surveys and find 9-10 mph to work well. I tell clients the accuracy is 0.2' +/-. That number is derived from testing on uneven ground with ATVs.
25ft is short. If you drive much more than 10mhp, the DC will not have enough time to recover form a save of one shot, before calcing distance of next shot and saving it.
Best to either slow down, or increase min distance.
I know for our past airport work, RTK was only good enough for the rough grade staking.
