Just curious how others deal with objects in drawings that may have been shot by reflectorless. For example a utility pole that may have been shot midway up the pole or a wall. Do you show all such objects at zero elevation, do you change it to match the surface model or leave as shot?
Would be great to hear how others handle this.
I give a height of -999m. I leave it out off the surface model.
I put in a rod height of 1000 feet when I take those shots so those points don't end up in the model
Likewise, rod height of 99 feet, keep it out of the TIN.
Exclude from the point group that I use for that surface.
I am cautious with the invalid elevation trick. You can move the point horizontally when staking using a projection.
We just add .X to the end of the descriptor.
Totalsurv, post: 326527, member: 8202 wrote: Just curious... how others handle this.
a) I have used the 99 foot rod gambit, as others do. And I try to collect all the reflectorless shots in a series. If the elevation is not valid I not only want to exclude it from the surface, I want it excluded from the point itself. Since I run all my data , including topo, through StarNet I have an opportunity to have StarNet read points with 99 foot rod as 2d data only, and put a -99999 foot elevation on such points, which LDT and C3d interpret as no elevation at all.
I could also simply edit the point list that comes out of the dc with -99999 elevations. But that is not how I roll.
b) add "VV" to the descriptor. Surface point group is set to exclude any points with "VV" in the descriptor from the surface. This is the system in place at my current place of employment.
c) I use field to finish to layerize points and draw linework. I do not use all the points I collect in the surface. The things that are likely to be shot with reflectorless (signs, poles, trees, fences, building corners, etc. are not used in the surface. I know a lot of you like to use some of those things in the surface. I don't. I take a few extra ground shots.
For example, typical practice might be to shoot a fence every 50 feet and use it as a breakline. Instead of that I shoot the corners only, and get ground shots along the length of the fence. The only extra shots are ground shots near the fence corners.
Totalsurv, post: 326527, member: 8202 wrote: Just curious how others deal with objects in drawings that may have been shot by reflectorless. For example a utility pole that may have been shot midway up the pole or a wall. Do you show all such objects at zero elevation, do you change it to match the surface model or leave as shot?
Would be great to hear how others handle this.
I set the instrument and rod to zero and SOMEHOW, it tells the DC to insert a zero elevation for the coordinate.
Otherwise, I typically shoot all power poles in one series, house corners, et cetera as a series so it's a couple of clicks to change the elevation to zero. I choose zero because if I'm contouring, Carlson ignores zero elevations. Not -999, but 0. 🙂
I too zero the elevations when processing.
Zero elevations around here could be a problem. A lot of the ground is reclaimed swampland and is below sea level, behind levees. The zero contour line exists!
This is how finish floors are built above base flood elevation.
As a matter of routine, all such shots should be purged from the coordinate file that you use to build your surface.
Create a separate file called "xyztopo.crd" and load all your points into it then go through and delete all of the "junk" shots. I NEVER use tree shots, meters or manholes, tops of transformer pads, loading dock elevations and other man-made elevated features. They are invalid when contouring t he grounds.
cptdent, post: 326605, member: 527 wrote: As a matter of routine, all such shots should be purged from the coordinate file that you use to build your surface.
Create a separate file called "xyztopo.crd" and load all your points into it then go through and delete all of the "junk" shots. I NEVER use tree shots, meters or manholes, tops of transformer pads, loading dock elevations and other man-made elevated features. They are invalid when contouring t he grounds.
You sure are yelling N E V E R a lot lately.
Brad Ott, post: 326606, member: 197 wrote: You sure are yelling N E V E R a lot lately.
We add "noel" to descriptor.
We add "noel" to the descriptor.
It is not just laser shots that should be set to zero elevation. It is so easy to set the data collector to elevations off. If you are not on the Coast, do it.
Paul in PA
Brad Ott, post: 326606, member: 197 wrote: You sure are yelling N E V E R a lot lately.
Yes because of all the stupid stuff I see people at work doing as a matter of routine. I've seen people find that the elevations are off 2.45 feet so they"move the contours up that amount" and everything is just peachy.
Contouring is not all that difficult. I have a 26 page Army manual that explains it all and was the major workbook in Carto School, yet I have met VERY few surveyors who actually know how to contour correctly. ("It's okay to use that invert elevation on that manhole because it will reflect the depth of the manhole." Really???)
There's a right way and a wrong way to do anything. Today doing things the wrong way is acceptable because it is easier and "everyone will know what I mean." Standards are being lowered and that really irks me. If you don't take pride in your CRAFT, go work as a Door Nazi at WalMart. It will suit you.
I think my question may have been misunderstood. I never use these points as part of the surface model. What I am saying is that in the cad file if a cad tech measures from a zero elevation point to a 3d point they will get a wild measurement.
It is obvious that most people just set these points to zero. I wonder though would it be a good idea to then set these points to match the surface model AFTER the surface model has been completed without their inclusion. This would produce a complete 3d cad file. Any thoughts?
Totalsurv, post: 326635, member: 8202 wrote: I think my question may have been misunderstood. I never use these points as part of the surface model. What I am saying is that in the cad file if a cad tech measures from a zero elevation point to a 3d point they will get a wild measurement.
It is obvious that most people just set these points to zero. I wonder though would it be a good idea to then set these points to match the surface model AFTER the surface model has been completed without their inclusion. This would produce a complete 3d cad file. Any thoughts?
NEGATIVE.
First off I never get wild measurements because my CAD software gives horizontal measurements which is typical for all survey work. You need to either fire your CAD software, your CAD technicians or both.
My CAD also is capable of ignoring all points at Zero elevation.
Are you trying to solve a problem or create a problem?
Paul in PA
Here is the DISTANCE command in Carlson.
It gives you a horizontal as well as a slope distance.
:stakeout:
DISTANCE
Specify distance-angle from [Linework/]? _nea to
Northing(Y) Easting(X) Elev(Z)
1456070.8966 547765.7048 79.0028
Pick second point or enter point number:
Northing(Y) Easting(X) Elev(Z)
1456088.9020 547760.3050 0.0000
Slope: -420.2806% -0.2379:1 -76.6161å¡ Bearing: N 16å¡41'39" W
Horiz Dist: 18.7976 Slope Dist: 81.2083 Elv Diff: -79.0028 Vert Ang: 283å¡23'02"