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Discussion: georeferencing in OCAD 12

in: Orienteering; General

Aug 2, 2017 2:32 AM # 
I am making a mtb-o using lidar contours from:

I used 6 grids:

I successfully created a contour map in OCAD 12 but I cannot upload gps routes correctly since it is not geo-referenced. How do I do this?
Aug 2, 2017 3:21 AM # 
normally when you import lidar data OCAD will automatically open a georeferencing window.

You might try looking at the OCAD learn videos.

There is one on georeferencing in the miscellaneous category, but I think what you really need is the DEM videos which cover importing Lidar data.

The videos seem to all be for v9 and v10. v12 will be a little different in some cases but you should be able to figure it out.

There is also an OCAD wiki that covers v12.
I haven't looked at the contents.
Aug 2, 2017 10:49 AM # 
Thank you. When I imported it did set coordinates, but GPS upload from file did not work ( tracks were very small, not aligned). Not sure where the error is
Aug 2, 2017 11:11 AM # 
Which datum / projection is used in the original file?
Aug 2, 2017 1:31 PM # 
I used the DEM import on OCAD 12 using the 6 LAS files from:

I used 6 grids:

Maybe I missed a step in the import DEM step? I have successfully imported GPS tracks into another map that was geo-referenced (not by me).

I'll have to check my other computer later for what the auto-projection is.
Aug 2, 2017 1:48 PM # 
OCAD is a pretty crap GIS tool.

Do all your GIS work in QGIS, so that you have full control over projections, then export everything to geotiffs/shape files all in a single projection that you choose and import them to OCAD. QGIS has great tools for georeferencing unreferenced data, and can manage projection on the fly for data from multiple sources. You still need to project it all to a common projection for OCAD to use though.
Aug 2, 2017 5:33 PM # 
Erik, the PASDA lidar projection is PA State Plane [North or South, depending on where in PA your map is], units are feet. The tiles use a shorthand 4-digit notation for the NW corner of the tile. The actual geo coords are likely larger. Perhaps (340000N,2490000E), and those are in feet not meters. [edit: I pulled tile 34002490PAS.las and confirmed the NW coord here. Each tile is 10000x10000 feet. The DEM should be the same.]
Aug 3, 2017 11:17 AM # 
thank you. I was able to resolve!!
Aug 3, 2017 11:20 AM # 
I think I needed to checkmark 'convert feet to meters' in the import step, but the tool works great for my purposes.
Aug 4, 2017 12:44 PM # 
Agree with edwarddes:
Aug 4, 2017 11:55 PM # 
I did a little lidar for a guy in State College.

This is the lastools' las2las command I used:

las2las -i *.las -olaz -sp83 PA_N -feet -elevation_feet -target_utm 18N

I verify UTM coordinates in Acme Mapper (a website) set to UTM. (The coordinates are for the crosshairs in the middle of the screen. I don't know if all of PA is UTM zone 18, but Acme mapper is a good way to check. {Update: Western PA is UTM 17.}

I also use Acme Mapper to view USGS topos for checking elevation values. Most of the USGS maps are in feet, but one zoom level is the 30x60 minute series which has metric elevations.

I try to use QGIS and other tools to convert all my basemap materials to UTM in meters, so it doesn't overly confuse OCAD. And no disrespect to OCAD---the feet-meters situation in the US is just a quagmire.
Aug 5, 2017 12:04 AM # 
I'm reasonably confident the OCAD feet-to-meters switch is inadequate. You can use that for scale and other things, but not georeferencing.

And it's honestly not worth it to take half measures. When you spend the time to get the projection right, or at least very close, it makes your life easy.
Aug 5, 2017 7:53 AM # 
Yes, fix in ArcGIS or QGIS
Aug 5, 2017 12:47 PM # 
Oh so glad Australia is in metres!
Aug 6, 2017 5:01 AM # 
Oh so glad NZ is narrow enough for a single grid!
Aug 7, 2017 4:59 PM # 
I've got a single large area I'd like to have mapped that spans zone 16 and 17. I've been scheming about how to handle that, and hopefully to show both UTM grids for adventure race purposes.
Aug 7, 2017 9:37 PM # 
Terje Mathisen:
Most of Norway is covered by UTM N32, 33 & 34, so for country-wide maps the usual approach is to use N33 for all of it, but for orienteering maps here in Southern Norway it is all N32. The fun part though is that the west coast (including Bergen, the second-largest city) should have been N31, but in order to avoid a zone boundary in the mountains, the UTM grid actually has an official exception to move the boundary out into the North Sea. :-)

This discussion thread is closed.