I am working with a LiDAR dataset which uses feet in state plane coordinates, extracting contours in OL-Laser, and importing them into OCAD. OCAD only seems to have state plane coordinates in meters, how do I deal with this inside OCAD, short of converting everything to meters earlier in the process?
Try importing as if they were meters, then "Stretch map" and then reset the real-world offset manually... perhaps not the best way but it should work. You'll preserve the state-plane north, which is a lot of help.
The O-maps YahooGroup might have an answer:
Oh yes, a better way... reproject your raw .LAS into UTM right away. Google LAStools. Something like las2las -sp83 MI_S -survey_feet -elevation_surveyfeet -target_utm 17T -i %1.las -o %1_UTM.las (check your state plane designator and UTM zone!)
Sweet, las2las should work. Thanks!
For the record, this worked just fine:
las2las -target_utm 16T -sp83 MI_S -feet -elevation_feet -i input.las -o output.las
is somewhat important. If your coordinates' abs. value is large, and you have high-res orthophotos, you may have an annoying offset for your lidar vs. orthophotos of a meter or several. Nothing that "Move Map" in OCAD wouldn't solve, but one shouldn't ever resort to that when using properly georeferenced source data.
U.S. survey foot versus international foot
Ah, but I think the data uses international feet, lasinfo and accompanying xml both say
Good catch. That's a surprise to me, I haven't seen lidar in international feet, but then I've only looked at data in California. Everything is in survey feet in California.
Very educational about survey feet though, for sure. Thanks!
It looks like lastools support xyz format now, anybody tried getting those XYZs directly into OCAD bypassing OL-Laser?