GEOGRAPHIC LOCATION - adding a geo tag to an already coordinated drawing

[pdonald001]

I've looked through the previous posts on this and my question isn't really answered, so I thought I'd lay out the process as I understand it. 

I have a DWG that is already coordinated to the New Zealand Transverse Mercator (NZTM) coordinate system, but the BIM Architect folk can't use it that way and I believe it needs to have a geo location assigned to it for it to work for them.

Steps I've followed:

1. Draw a point on my dwg, near my main drawing information
2. Copy the coordinates of the point into https://epsg.io 
3. Transform from NZTM (EPSG 2193) to WGS 84 (EPSG 4326)
4. Go back to CAD and put GEO in the command line and click on GEOGRAPHIC LOCATION
5. B for Bing
6. Paste the WGS coords from #3 into the address bar and press enter
7. Drop a marker here
8. NEXT
9. Choose NZTM > NEXT
10. Select the point from #1
11. Move mouse up to indicate north and click

This works pretty well, but the aerial doesn't line up that great with the boundaries I have in my DWG. This could be to do with the boundaries not being entirely accurate themselves, or it could be something I'm missing in the conversion process.

Does this look alright? Is there anything I'm missing?

Hoping this helps other people looking for more current info too.

[pendean]

@pdonald001 Your exact LT version as listed by the ABOUT command inside the program is...?

And is the other person also using LT or plain AutoCAD, or some other software altogether?

[pdonald001]

←Me

Waiting to hear back from them with more information, including software details. This is the first time anybody has ever had a problem with our outputs (other than the usually m/mm issues between surveyors and architects), so I'm really confused at to what their issue is. I'll update once I have more info.

***update***

They are using Revit. They said what I did worked, but it's the wrong file. So I think the outstandingly obvious issue here is failure to communicate all of the required information in one email, instead of a whole chain. *facepalm* Anyway, I hope my step-by-step can help someone else.

[pdonald001]

Another update.

So the plan they have that they want to line it up to is from a previous stage of the job and was done in a different coordinate system (local, rather than national). So I geolocated both of them as described above. But the aerial shows a bit of a difference between the two, which will be why they're having problems. Is there a way to refine this more? Or is it just the consequence of having LT instead of something more GeoSpecial. 

[pendean]

@pdonald001 AFAIK there is nothing you can do in LT to fix an issue in REVIT sadly, sorry.

They (and you if you want to get that involved) might find more relevant help in the REVIT forums.

[pdonald001 · Accepted solution]

I don't think it's a Revit issue per se, just that the transformation between the two coordinate systems is not being handled properly by LT. Which is not at all surprising.

Solution #1: Geo-referencing plans that are in the same coordinate system works fine. Plans that are in different coordinate systems do not transform well and LT does warn you of this when you XREF.

And then it turns out that the drawing they ACTUALLY wanted, was in the same coordinate system after all. So now they're both georeferenced to the same point and look the same and drop on top of each other the same, so that should solve it.

Solution #2: Make sure the client knows what they actually want, before chasing your tail around the internet.