civil 3d; decimal degrees to xyz

[_autocad]

Have a 7 MB file of bathymetry in decimal degrees with depths, and can't seem to change the drawing to xyz coordinates. tried changing the coordinate system by editing drawing settings and putting it in utm but no luck. it's in a small area so not too worried about transformation error. any help would be greatly appreciated.

Edited October 8, 2013 by _autocad

[_autocad]

Have a 7 MB file of bathymetry in decimal degrees with depths, and can't seem to change the drawing to xyz coordinates. tried changing the coordinate system by editing drawing settings and putting it in utm but no luck. it's in a small area so not too worried about transformation error. any help would be greatly appreciated.

[Tyke]

Can you post a small extract from your DWG. Use the command WBLOCK and select just a small area of your data, so we can look at it and offere more meaningful suggestions.

[satishrajdev]

I am also from surveying field, i used to convert coordinates from UTM to Geo and GEo to UTM, But I didnt understand you prob,

1. Do you have txt or dwg file of 7mb?

2. Did you try Coordinate Calculator for the conversion of Decimal degree to UTM.

3. Which datum r u using to convert coords?

 

Otherwise, Attached your file here....

[_autocad]

All I have is the dwg, no txt/csv file, I'm going to utm.

Thank you!

bathy.dwg

[satishrajdev]

All I have is the dwg, no txt/csv file, I'm going to utm.

Thank you!

 

The drawing you have provided contains only contours and points,

It doesn't have Geographich Coords in it??? what you want to do with that?

Where is bathymetry labels or soundings???

 

Which datum r u using for conversion?

[Tyke]

What are the units of the drawing? Kilometres? WGS decimal coordinates? From which part of the world has this data come.

 

Your polylines/contours each have a Z value and each node on the polylines have X and Y coordinates, therefore you have X,Y,Z coordinates.

 

Once you have determined the original coordinate system and you know the units used in the drawing, you then need to determine the target coordinate system. UTM is not a valid coordinate system, it stands for Universal Transverse Mercator and is a projection used to represent the curved surface of the earth of a flat plane. Different coordinate systems are based on a UTM, you need to know which one. Then you need either AutoCAD MAP, Civil 3D or a 3rd party program to transform your drawing. Your profile says you are using MAP 3D 2012 so you can do the transformation. If you need help on the method the User Help Files cover the process in detail.

[Emigrato]

From which part of the world has this data come

 

Basing on drawing coordinates, seems like we're talking about the Mogadishu coast (Somalia).

 

If so, in the attachment here's my conversion result, in meters (EPSG:32639).

 

http://novarese.t15.org/cadtutor/somal-w.zip

 

[_autocad]

Thanks for that Emigrato, just what I was trying to do.... but how did you do it? Global Mapper?

[_autocad]

Tyke; if you check the bottom left hand corner of your autocad screen in model space it will always show you the grid coords or decimal degrees etc; the units of your dwg. I am in decimal degrees and want to go to utm, and yes it is wgs84 lat long. Simply changing the dwg settings (geodetics) by right clicking on the dwg name in the settings tab in civil 3d does not work, so hoping for any suggestions.

[SLW210]

I merged your threads.

 

Please do not create more than one thread for the same question.

[_autocad]

The link is not valid? It points back to this post in a search. It's definitely what I need though....

thanks

[Emigrato]

Thanks ... how did you do it?

 

You are welcome, sir.

 

After converting your .DWG to 2004 version by means of Autodesk Trueview, I typed some middle X,Y in Google Earth just to figure out where I was in the world, then I processed the drawing with my glorious Autocad Map2006 (first _ADEDRAWINGS then _ADEQUERY to transform all from EPSG:4326 to EPSG:32639).

 

P.S.

Maybe you're already aware of: if you open my attachment, and perform the command _MAPTRACKCS, you can "see" in realtime both UTM and LL84 coordinates.

 

[_autocad]

Ingenious !

[Tyke]

Tyke; if you check the bottom left hand corner of your autocad screen in model space it will always show you the grid coords or decimal degrees etc; the units of your dwg. I am in decimal degrees and want to go to utm, and yes it is wgs84 lat long.

 

Yes I am very well aware that the coordinates of the cursor are shown bottom left, they have been for many, many years. When I load your drawing the coordinates are set to 'absolute' not 'geodetic' and the angular units (not the coordinate units) are set to decimal degrees with a precision of '0'. More information that you are working in latitude and longitude is not to be seen in your drawing.