Hi JAK:
The conversion should be automatic. But there are a couple of known issues that cause the conversion to fail. These are fixed in SS3. If you import the LAS and find that the conversion to feet did not occur, then you can work around as follows:
- Import the LAS into a metric dgn
- Export the surface to TIN file
- Then import the TIN into your Imperial dgn.
Besdies fixing the above bug, it is a little more powerful in Geopak SS3 than SS2. GEOPAK SS3 also provides some additional benefits for automatically taking care of ground to grid adjustment. Note: In SS3, Data Acquisition is renamed Survey. In SS3 the process is:
- In the DGN file, make sure the proper coordinate system is assigned. You do this at Tools > Geographic > Assign Geographic Coordinate System, then pick your state system from the list.
- If you need to account for ground to grid adjsutment (elevation factor), then in the GCS dialog click the first button to open the properties of the assigned GCS. At the bottom of the properties, change transform to Helmert and enter the elevation factor in paramter A.
- Do all of previous settings in your seed file for convenience.
- Now to create the terrain from LAS, in task navigation choose Create Terrain From File
- Pick the LAS file.
- In the next dialog make sure that source GCS system is set to UTM zone xx metric
- The target system wil be detected from the DGN.
- Click import.
Note that the above Coordinate Systen assignment is very powerful. Besides terrain models, it also allows you to proerly align various dgn and raster files when referencing even if the reference files are in completely different coordinate systems. Coordinate systems technology exists in Microstation SS2 but not the ground to grid adjustment factor. As noted above, Data Acquisition in SS2 does not fully exploit the GCS capabilities.