Geolocate drawing and overlay NAD83 Coordinate System

[Anonymous]

Hello, I have 2021 Autocad installed. I discovered how to geolocate a drawing with WGS84, is there a way to geolocate a drawing with the NAD83 coordinate system and the Ohio state plane north, for example?

If so how accurate would choosing points be, accurate enough to input the points for general site layout with a GPS receiver?

[CodeDing]

@Anonymous ,

The geo-locating ability in AutoCAD is an amazing feature, but when you start referring to survey work, you should, ideally, be using Civil 3D... But I don't know your full process flow or abilities, so to answer your question for AutoCAD...

Run GEO command:

Select Location from Map:

Search for "Ohio", then select "Drop Marker Here", then hit "Next":

(this step is usually a bit confusing for people, the "marker" that gets dropped is the location that we will select in model space later in this process... So, if I drop a marker at a SPECIFIC Lat/Long, then later in this geolocation process, I will be selecting a point in model space telling AutoCAD that is where my Lat/Long belongs)

Select the OH83-NF coordinate system (assuming that's the one you want), then MAKE SURE your UNITS are correct (For Architectural use "Inches", for Decimal use "Feet"), then select Next:

Now, select a point in model space (this is the point of our "Marker" that we dropped earlier in the process):

Last, select the angle for North (You can alter north by selecting ANY direction as north, but I ALWAYS use Ortho and have north straight up from previous point):

You can select any angle for North ...I prefer Ortho + straight up.

Now, you can use the "Geolocation" contextual ribbon to manage your imagery.

Hope that helps. Here's more about the GEOGRAPHICLOCATION command.

Best,

~DD

[ryan_rinconesBGVVS]

After using Civil 3D for over a decade, I'm now in a position with only basic Autocad . . . I'm up to speed with the above, but can't find a way to display the state plane coordinate VALUES that correspond to the coord. reference system.  The closest I've come, per above, is to have the randomly chosen initial marker (I have no SPC survey points to reference) and the initial prompt for 0,0,0.  Is there no way to gain access to the state plane coordinates after referencing the imagery???

[Pointdump]

Hi Ryan,
Welcome to the Autodesk Forums.
Vanilla AutoCAD really limits you. If you have a current subscription to AutoCAD you can get Map 3D at no extra charge.
Dave

[autoid374ceb4990]

Does your county have a GIS system?  Perhaps they have planimetric and/or digital orthos located on NAD83?  Many years ago my company and another survey company set up our county's GIS control survey using GPS.  They can even furnish planimetric maps in DWG format.

[R_Tweed]

Have you tried to locate your site using the kml/kmz location point file option?

This would set the geolocation map to those coordinates rather than a local coordinate system.  The map option converts the mapping coordinates to a local system 0,0 or 1000,1000 etc.. 

[CGBenner]

@ryan_rinconesBGVVS 

Hello, do you still need help with this question?

[CodeDing]

@ryan_rinconesBGVVS ,

While it may somehow be possible to accurate correlate the AutoCAD (vanilla) map to its correct location in cartesian coordinates, I would never recommend it (as it may give future users a false sense of security/comfort), and I would not encourage you to pursue it because if you need that level of accuracy for your work, you should be using the correct tool for the job.

(plus, I don't know a proper way to do it)

Best,

~DD

[ryan_rinconesBGVVS]

This is the approach I discovered:

1) Create a point near project side in Google Earth, save as .kml

2) Use on-line .kml to .dwf converter (browser-based, no app install; this multi-step process creates a .dxf file with a state plane reference!)

3) I opened this .dxf then did a copy/paste from/to 0, 0 of the point object into the desired .dwg

4) NOW I had a reference object in the .dwg - per NAD83 FL East US foot coords. in my case - to reference for the GEO command, where it needs a WGS (Lat-Long) position initially, which is then correlated to user-specified SP N/E coordinates . . . after that you're cooking with Crisco - the Geolocation tab is available with several map options.

KERPLUNK . . .

RR

[CodeDing]

@ryan_rinconesBGVVS ,

Not sure how precise your measurements need to be... but honestly the best approach would probably include using the NGS NCAT tool:

https://www.ngs.noaa.gov/NCAT/ 

But again, this gets into using the right tools for the right job, and we don't know your proper workflow

Best,

~DD

[ryan_rinconesBGVVS]

I think Lat-Long with 2 decimal place seconds value gets me pretty close - within a foot or two I think.  Typical survey-grade locations take state plane coords to 3 or even 4 decimal places but that LOD isn't needed here.