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CAD data to small map

Started by Forrest hunters, March 23, 2011, 02:21:05 PM

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Forrest hunters

Oregon 450 idea.

Alright i know this is not as accurate as a survey but I would like to make a map with some lines just of my moms property so I can tell if a few trees are on her property or the neighbors.  The neighbors are all cool and probably wont mind if i tap them for maple syrup or not.  I posted this on another forum and didnt get very far.  Can i make a CAD drawing and inport that to my gps with some sort of software or is there some other way to do it. 

I did project a point to her corners but when I was walking if i went around a tree i would have to watch the pointer to get back on track.  Looking for something easier that I can see what side of the line I'm on.  If the trees im looking at have a 10 foot accuracy on the gps i know im good from where i project the line.  also if i am off by more than that I can just tag the tree and ask the neighbor.

Just looking to be close and an easy way to do it. 


This sounds like a Garmin Custom Map project. But you'll need to locate some of the property well enough so you can georeference it in Google Earth and you'll need to get your drawing into jpeg format.

This is Garmin's how to site.

The other, expensive, way to do it would be to import a DXF file into Global Mapper or a similar program, but you'd still need to georeference the DXF after import.


Garmin's vector maps have limited resolution that might be problem for this kind of project, but Custom Maps can be much more accurate. I wrote about these issues here after making a map of trails on my own property:,1335.0.html


Quote from: Forrest hunters on March 23, 2011, 02:21:05 PM
Just looking to be close and an easy way to do it. 

Mapsource (create a track) will do exactly what your wanting and will be as accurate as anything else will be and definitely the simplest.  See my detailed explanation in your thread at GroundSpeak.



With the proper software this is an easy task.  I don't know what you have available.  Personally, I would use a custom map for this - with an aerial photo base if you want one.  Most states have GIS repositories and free high-res orthophotos. 

Assuming you only have one end of the line - I would first gather as many property line points as you can with your 450 (around the parcel perimeter), using the waypoint averaging fuction and preferably over an extended period of time.  Import these points into GIS (ie, ArcMap, GlobalMapper, or a freeware alternative) on top of your aerial basemap. 

Next plot the deed in GIS (assuming it has a metes and bounds description) and then rotate/translate the plot onto your waypoints as best you can.  Now export a geotiff image and upload that into G-Raster freeware.  Export the KMZ from G-raster and drag it into the 450's CustomMap folder.

You could go through the process above in CAD, but the procedure for importing points and exporting/converting a map is a bit more complex.  CAD has limited raster export options.

If you are projecting with your 450 from a single known waypoint (an iron pipe or rod) be careful using deed bearings.  They are relative to the year they were recorded and can vary significantly from the current bearing of a line.  If you could actually locate the other end of the property line you would not need to go through the process above - you could inverse between the 2 waypoints and get the real-world bearing.


Forrest hunters


Wow.  That is an indepth explaination.  I only wish i knew how to do it.  I am new to this gps thing.  I did do the route thing with mapsource and will see how that fares.  I think i remember where all the corners are so it is just finding them.  Might have my daughter get her cheap metal detector out and see if she can locate them.  Then I can project the points a little more accurately.


Maybe indepth, but it's the process to follow if you want a relatively accurate deed plot on a Garmin.  I've done it dozens of times to get pre-survey 'recon' maps with an aerial photo base into my 550.  It's not that complex but does require some software that can be costly.  I usually plot the deed as I've described and rotate it onto an orthophoto, then add some waypoints at the property corners.  The waypoints transfer to the Oregon through a GPX file output from DNR Garmin software.

I recommend downloading G-Raster (freeware) if you would like to start getting some imagery onto your Oregon.  It has links in the menu for free raster sources.

Again, if you can find the two endpoints of the line you want to follow then you'd be better off.