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Importing .dxf data, then export to .kml


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#1 Bryan

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Posted 02 July 2008 - 11:43 AM

I have a .dxf file that was exported from Terramodel. This is a simple roadway alignment that I am trying to convert it to a .kml to overlay on Google Earth.


My problem seems to be in selecting the projection on the import file. The plans I made the layout from do not list the datum used and I'm a little unsure if it's state plane or grid. I'm a little over my head in some the technical terminology here, but as an example, a known point of N13871013.5081 E2294587.1979 on Google Earth matches to N13865515.2258,E2297385.0656 in the .dxf files.

As I said, there are no indications of the system they used on these plans.....but others sets from the same entity usually say "A conversion factor of 1.00015 was used in preparing these plans" and I'm fairly confident that would hold try for these as well.

Edit: I have confirmed that the plans were in the "State Plane Coordinate System in NAD83" and from what I've found, it should be zone 14....but when I try to import it under those parameters the points still end up Kansas when they should be in central Texas!


Could someone give me a quick tutorial on how I can accurately get this data in to a .kml using ExpertGPS? The ultimate goal is to have a .kml to send to others, as well as be able to save the alignment as tracks to use in my handheld gps (Garmin 60cs).

#2 Dan Foster

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Posted 02 July 2008 - 03:17 PM

In ExpertGPS Pro, click Edit/Preferences/My Coordinate Formats.

Click Add, and drill down the location tree on the left side until you get to Texas. You'll now need to figure out which Texas state plane system was used. Your choices are Texas Central, North Central, North, South Central, and South. (And you need to know if the DXF was produced in Meters, or Feet. Probably Meters for NAD83)

I've sent you an email - if you have any trouble, send me the DXF in question and I'll see what I can do to help get it imported properly in ExpertGPS.

Once it is positioned correctly in ExpertGPS, just press F7 or Export on the File menu, and save in .kml format.

#3 Dan Foster

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Posted 09 September 2008 - 12:03 PM

Texas State Plane Coordinates in ExpertGPS mapping software




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