Lat. and Long. Incorrect after Tranformation

[lee_maverick]

My survey is set up in NAD83 Texas State Planes, South Zone, US Foot.

I am tring to set the GRID, so i am useing the Transformation useing the reference point and rotation point.

I can set the PLANT GRID and it works great. I can label points and get the Survey N and E and Grid N and E everything looks great.

Here is the issue,

After i apply the Transformation useing the reference point and rotation point, the LAT and LONG no longer are correct.

before the tranformation lat and long display correct:

w97 15' 80"

n27 53' 22"

after the tranformation lat and long display incorrect:

w100 37'54'

s15 28'44"

what am i doing wrog????

any help would be nice, I would like to beable to label survey NE, grid NE and lat and long

[antoniovinci]

Between different datums, you should NOT transform manually anything, sir.

Go with one of the classic ways:

1. _MAPCONNECT a Nad83 shapefile in a Wgs84 drawing
2. _ADEDRAWINGS a Nad83 drawing in a Wgs84 drawing, then perform a "draw query"
3. _MAPEXPORT a Nad83 drawing to shape Wgs84, then _MAPIMPORT it in a Wgs84 drawing

[lee_maverick]

May be I was unclear.

I am not going "Between different datums".

My drawing is set up in NAD83 Texas State Planes, South Zone, US Foot., that will not change.

1. I want to set up a PLANT GRID.

(I can get this to work but it changes the LAT and LONG.,

I do this by useing the transformation settings "see attachment")

2. I also would like to know the LAT and LONG of whatever point while

 keeping it in NAD83 Texas State Planes, South Zone, US Foot.

(This works as long as I don’t set the GRID NORTHING and EASTING)

I guess my question is how do you set a GRID NORTHING and EASTING, without it changing your LAT and LONG?

Seem like the function is there but somthing is not set correctly.

Thanks

[ctbailey · Accepted solution]

When you set a projection up by choosing a specific State Plane grid system, you can not apply a "second" transformation by using the "Transform" tools and expect the same answer.

Civil 3D can only handle one project transformation at a time, per drawing.

Your PLANT GRID work will be best done in a seperate drawing, using a local coordinate system (5000,5000) and then apply the transformation settings so you can easily label "grid" items while you have set up the Transformation settings.

THEN

XREF that plant drawing under the Site drawing.  this way, you can label the PLANT GRID items, and they will show up in the Siteplan drawing - which will ofcourse be correctly set up in state plane grid, so you can label geodetic locations with their correct LAT/LONG.

This is how I would do it.  It makes sense - when people say "PLANT GRID" I immediately think of inside a building, which one could argue doesnt belong in a "geodetic"  (albeit an approximate Geodetic) system.

Good luck Lee!

Craig

[lee_maverick]

That makes sence to me, thanks for the reply.

[citaylor]

This is probably the same problem in a different wrapper. Using C3D 2014.

My file is in state plane and I used the transformation tab to set up a plant grid.

I have set up an alternate UCS for plant grid.  As I swap UCS's I can label correctly in either system, but when I try to ID a point in the plant grid system I get bogus coordinates.Only slightly bogus, so it is a bit sneaky. If I hadn't been IDing an even grid point I may no have noticed. So to ID a point correctly I have to actually place a label.  Correct?