NAD83 & NAD27 on the same Coordinate Tag?

[rchustz]

Hello,

I have a work process that is a bit of a pain.  We have to show both NAD83 SPCS + Lat/Long and NAD27 SPCS + Lat/Long on the same coordinate tabs.  We have to do this several times per drawing, on multiple drawings.  Right now we get the NAD83 auto populated, as our drawing is in NAD83.  Then we have to convert all of the coordinates to NAD27 and manually type them into the Coordinate Tag.  Obviously, this leaves a lot of room for operator error.  This also makes it a nightmare when we have to revise any of the plats and move the coordinate tags.  In a former life, I worked for a company that used Carlson and we had a tag that would show both coordinate systems automatically.  Is there any way to do something similar in Civil3D?  I feel like there should be, but I feel like getting into any options like this is deep down a rabbit hole of button clicks that I just don't understand.  I'd appreciate any help anyone can lend me!  Have a great day!

Ralph

[rl_jackson]

I would think your best bet here would be to create to create expressions for your labels to compute the NAD27 Coordinates and Lat/Long. You'd need to know what the difference was between the two datums (which varies by state) and then once you have the coordinates calculated in NAD27 you could use them to calculate the LAT/LONG. 

Let me think on this a little longer, as its an unusual request.... Maybe @Pointdump has a better idea.

[rchustz]

Thanks Rick.  I'll take a look into create expressions and see what I can figure out!

[rl_jackson]

Out of curiosity do you have a NAD83 point, that you also have a NAD27 values for both coordinates and lat/long. Was looking to try something. If so I'd need the State Plane Zone your in, as well

[rchustz]

I got the Northings and Eastings working, but am having some trouble with the expression to get the Lat/Long to update correctly.  I'm going to work on this some more tomorrow, but you have been a tremendous help so far sir!

[rl_jackson]

Glad I could get you in a direction that worked (sort of) If you could shot me a NAD83/NAD27 Coordinate value, along with State specifics.  I'd like to test another solution that I'm thinking may work.

[rchustz]

I do have that. I just turned my computer off, so I will flag this and send you a screen shot in the morning. Would that help?

[rl_jackson]

Purrfecto, with State Zone data

[Pointdump]

Hi Ralph,
Welcome to the Autodesk Forums.
I tried to tackle this in 2015 but was unsuccessful. The only thing I can suggest, to save you some manual typing, is to use "Transfer Points" to get the NAD27 Northings and Eastings and Lats and Longs. Then use a UDP to allow labelling everything.
Dave

[TerryDotson]

If you were to consider third party add-ons, DotSoft's C3DTools contains an Alternate Coordinate PointUDP tool.  It lets you designate any number of known coordinate systems (separated by commas like KY-N,KY83-NF,LL83,LL27 which it remembers for subsequent runs).  It then lets you select CogoPoints and does all the projections using the Autodesk CS Engine (this is not simple math) and pushes the values onto those same points as PointUDP.  That way you can simply select the UDP in your Civil3D labeling process, point tables, exports, etc.  Also includes an elevation option Y/N to handle feet <> meters, etc.

[AllenJessup]

Be careful in converting the coordinates. It's more than just shifting the N,E.

https://prd-wret.s3-us-west-2.amazonaws.com/assets/palladium/production/atoms/files/Datum%20Shifts.p...

If you have the AEC Collection. You might be able to create an AutoCAD table of the points. Then export the points to a CSV file and use Corpscon to convert them (if you're in North America). Then import the resulting file to the Table.

Just a guess on my part. I've never had to do it.

[AllenJessup]

If you do this often. @TerryDotson 's DotSoft's C3DTools may be well worth the price. They also contain may other useful tools.

[rchustz]

Try these out.  I'm very excited to see what you come up with!

[rchustz]

I will definitely look into this!  I appreciate the info!

[rchustz]

I will 100% check this software out.  This looks like it could be extremely useful for a lot of other functions, just at a glance.

[rchustz]

We use CorpsCon, and some other tools, to complete and QA/QC the conversions already.  However, I was unaware that there is a way to import a converted table into CAD.  I will look into this some more.  I am reading up on your link for the datum shifts now, and appreciate the link.  I know it's not as straight forward as just shifting the N and E, so I was digging into this more anyway.  You definitely helped save me some leg work!

[Pointdump]

Ralph,
I grabbed 3 CORS Station Coordinates.(Published Coords)
Open a new drawing and assign New Mexico East NAD27(EPSG:32012). Create a Point File Format to be able to import and transform New Mexico East NAD83(EPSG:2257) Points. Compare with CORPSCON transformation. Export the NAD27 Northings, Eastings, Latitudes, and Longitudes.
Open a new drawing and assign New Mexico East NAD83(EPSG:2257). Import the NAD83 Points.
Create 4 UDP's:
Northing-NAD27
Easting-NAD27
Latitude-NAD27
Longitude-NAD27
Create a Point File Format using these UDP's. Import the NAD27 UDP's. Overwrite the NAD83 Points. Create a Label Style with everything. Whew! Terry's software is way easier.
Drawings attached.
Dave

[rchustz]

Dave,

That's pretty incredible.  I actually got a trial version of Terry's software yesterday and started messing around with it.  I was able to get the NAD83 .dwg to spit out NAD27 SPCS in the labels that come with the software.  I haven't figured out how to get it to do Lat/Long yet.  It seems like you can only do 1 or the other, and not both.  However, I have only just started messing with it.  As it stands, I see a TON of other applications for his software so once I complete so more testing we are buying at least 10 seats.  I really appreciate everyone's time!  I will definitely come back to this forum with more questions!  You were all very helpful.  Have a great weekend everyone!

Ralph

[AllenJessup]

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@Pointdump wrote:

Whew! Terry's software is way easier.

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Yes. But you did it!

[TerryDotson]

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@rchustz wrote:

I haven't figured out how to get it to do Lat/Long yet.  It seems like you can only do 1 or the other, and not both.  However, I have only just started messing with it.

You should be able to specify any number of systems by names, separated by commas.  As mentioned, for me in KY these might apply KY-N,KY83-NF,LL83,LL27 while it may have been tested more with state plane than lat/long I will test more here.   If you wish, send me a small .DWG  with a couple of CogoPoints and the names of the systems.

If there is any improvement needed it will be added ASAP.