Data Acquisition Lidar LAS file

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.

Robert,

I'm glad to hear of the improvements to the SS3 LAS import with regards to handling the ground to grid adjustments, however I have not been able to get the LAS import to even work in SS3.(Inroads)

I have filed D-123326 with support.

When I  use the "Create Terrain from file" and select the LAS, Nothing at all happens.

This is great tool and I hope this issue can be resolved in a refresh version.

Hi rdoyne,

While this doesn't address the "Create from File" tool not working, another option to create a terrain element from an LAS file is to display the data from the LAS file as a Point Cloud element in MicroStation and then use the Civil tool "Create from Point Cloud" to build your DTM from that Point Cloud.

The MicroStation Point Cloud tools will convert the LAS to a POD and display it.

You can then create a Terrain element from the entire point cloud or use a fence to section off an area of the point cloud and create a terrain from within the fence.

If the LAS contains point classifications, you can toggle off the display of the classifications you wish to exclude from the terrain, and they will not be included in the terrain you create.

HTHs

Hi rdoyne,

While this doesn't address the "Create from File" tool not working, another option to create a terrain element from an LAS file is to display the data from the LAS file as a Point Cloud element in MicroStation and then use the Civil tool "Create from Point Cloud" to build your DTM from that Point Cloud.

The MicroStation Point Cloud tools will convert the LAS to a POD and display it.

You can then create a Terrain element from the entire point cloud or use a fence to section off an area of the point cloud and create a terrain from within the fence.

If the LAS contains point classifications, you can toggle off the display of the classifications you wish to exclude from the terrain, and they will not be included in the terrain you create.

HTHs