Bandwagon's Drones Thread

Damn........... sweet.

edit: what was the ultimate accuracy you got for the map? looking at it, horizontally looks good to me- but not knowing the record distance from "point a to point b" i have no idea how close to that you got.

we term accuracy/precision in terms of error acceptable error is 1 in 12000 or "higher" (1 in 12000 is 1' error in 12000')
the way surveyors term it. "the relative error in closure is not less than 1 in 12000"(or 10,000 or 15,000 etc) (lawyers want " is greater than" instead of "is not less than" however "greater than" 1 in 12000 would actually mean less precise.). it is the 2nd number that is the important one, laymen want the number to be closer to "1" but surveyors want the number closer to "0" in terms of precision

1 in 10000 is less precise than 1 in 12000 which is less than 1 in 15000 but 1 in 10000 is "greater than" 1 in 12000 in terms of the actual number.

weird that way, the most precise survey i have done on the field was an island survey in fairhaven mass the survey covered about 1.5 miles of traverse or so , the error- raw no adjusting of any numbers- was 1 in 55000, the court accepted our traverse without adjustments (land court requires 1 in 15000 minimum precision) farthest 2 points were about 4500 feet apart but the distance between those two control points was off from "record" by 0.05' (about half an inch) which means, the record distance was still "in the holes" (2 granite bounds with 1/2" diameter drillholes- we shoot the center of the drill holes. the distance shot- the record distance could still be shot "within the drill holes"

Very cool. How much is 3d printer?

No shit man you're doing awesome stuff for a bargain. How big can it do?

Seem pretty easily to print in tiles and put them together later?

TENTH vertical or horizontal?

if vertical, awesome, Significantly more precise than a normal topographic survey would get-mainly due to the "coverage" of the topo. a survey that large would get -along the road, MAYBE 1 shot every 30 feet plus any structures signs etc, with the pictures, it is more like 1 shot every foot also a topo & site survey that large would take a crew of 4- locating all trees, natural features and artificial structures, probably at least 3 weeks....


if horizontal- depends on the distance...10th in 100' isn't that good(1 in 1k--one foot in 1000 feet error), tenth in 1000 feet is very good, (precision would be 1 in 10k-good enough for 80+% of the property line survey work most surveyorsdo(error of 1 foot in 10k feet)) once you get to tenth in ~1200ft(one in 12k) or more would be awesome, mass land court worthy survey is 1 in 15k(one tenth in 1500 feet).

oh ya happy birthday a bit late, my 50th (ugh) is 2 weeks from friday

it is just precision/accuracy.. how precise the survey is.

for survey it is error of closure - usually it is our survey traverse and the ties to the control points are determine precision/accuracy- the control lines and ties we use to locate existing record monuments

how to explain it.... for survey, nongps- we use a total station and a prism to accurately do shots via the built in laser in the total station.

for error of closure lets take that upper residential area from that picture. say there are record monuments at only 4 of the corners - one by the atheletic field on the lower right, one down the road to the left at the bridge by the dry creek bed, one past the school and at the corner to the NE and one @ the nw corner near that ?farmland? that is cleared.... we would set up the total station/tripod -either on the control point or via a stake or pk nail in the pavement - somewhere- so we could see at least 1 of the control points(if we were not "on it") - direct line of sight. then we would set up another tripod with a tribrach w/prism on a random point we set - or if we could see direct line of sight to a 2nd point on that point, we'd level the instrument, set 0 on the gun, "shoot" the distance. and record the distance to the nearest hundredth of a foot (or thousandth depending on the setting. total stations read angles to - depending on the instrument, nearest second or 2 seconds or 5 seconds... degrees minutes seconds, a circle has 359 degrees 59 minutes and 60 seconds btw.... once zero is set, another tripod with a prism - would be setup on a traverse point - a point set in the ground randomly, heading towards the points we cannot see- we shoot the angle and distance to that- double the angle to be a bit more precise/accurate (though half the time you can skip this part), then after locating all the control points you can from the current setup, move to the next point, sight where you just were (unclip total station, carry to tripod, unclip prism., lock total station. level, set zero on where you were, locate control points, set new traverse point,,, rinse and repeat until going around, until you locate your last point, then ultimately setup where you locate your first back sight point from a new traverse point, closing the traverse would be setting on the initial back sight point, backsighting the last traverse point, then sighting your intial traverse point "1" the error of closure, the precision, the accuracy is...how close the traverse loop closes in on itself. so say the point your started at-your last shot is off by .15 feet..

error of closure is...the perimeter under the error...so -.15/2000 feet (say a 2000foot perimeter) is basically a 1 in 13333.33 - anything over 1 in 10k is good anything over 1 in 12k better anything over 1 in 15k is "best"
anything higher than that is just gravy at a min 1 personally shoot for 1 in 15..just because no adjustments are usually needed to the traverse angles.

in terms of record monuments. the plans of record at the registry (or whatever it is called out there) should have known distances between the control points be it, 50' 100' 1000' or any distance in between...

you then use your record shots you took to the control points and ...compare field to record. so say the distance between the 2 farthest control points is 1200 feet.. field you got 1199.90'(and the other control points are similar) off by...a tenth... which for any surveyor,,,would take depending on how the other monuments fell, you might center the error, or shift i more towards one or the other. your flyover control points were shot by the surveyor as being X feet apart (3? in a triangle or whatever you used). you when you made the plan "full size" most likely used these distances to scale the map. the surveyor then took your 3d mesh and overlaid it onto their monument survey which was tied into the control points... and everything checked to a tenth...

ya i got long winded

btw, that is DAMN good.