This is a quick overview of importing LIDAR data and importing LAS and LAZ files in particular.

 

Create a new file

 

The first step is to create a new Ezigrade file. Open Ezigrade and click on File New.

 

 

Browse to a folder or create a new folder and enter a file name in the "file name:" field.

 

 

Under the File menu check the units meters/feet etc. This normally only needs to be checked once. However users in Canada for example may use jobs in different units depending on the client. We now have an empty job:

 

 

The LAS/LAZ import dialog

 

Click on Import -> LAS/LAZ and we get the following dialog:

 

 

 

First click on "browse to LAS / LAZ" and select the file to import. Click on "read header" and then "read points".  We have then pressed on "display points".

 

 

In this case we have over a million points and the points displayed make a solid contiguous blob. We could at this stage click OK and then import the points into Ezigrade. Ezigrade can handle a million point job but things will be very slow. At this stage you need to decide what you need to do with the data. If you want to use the lidar data as a guide for land grading then we need less points.

 

To thin the data look along the bottom and you will seesome radio buttons. If you select for example 1:9 then every 9th point is kept. The screen shot below shows the points used if we keep 1 in 16 and we have 116,000 points in the job.

 

 

We will go with this so click on OK and the points are imported.

 

 

Visualizing the data:

 

We need to triangulate the job so click on Contour -> Form Model. I also created contours from Contour -> Form Contours.

 

I also went to the Contour -> Surface Colors and shaded the triangles by colors.

 

Also from File -> Geoid we set the UTM zone to 14.

 

 

And we can display something like this:

 

 

 

Doing a Field Grading:

 

In this job we have roughly 116,000 points. I would suggest that you keep point numbers within a section below 30000 points. Bigger than this and the job starts to slow down considerably. In this case assume we want to grade the job within the confines of the surrounding roads. You can click in the section as below.

 

 

Now click on Fields -> Grid and put in a 6m grid. This drops the points used from 39000 to 18000. So speeding things up.

 

 

It is worthwhile reviewing the shaded triangles to make sure there is not a noticeable change in the job:

 

 

 

In this case we are probably good as the job looks intact. You could also import more points from the LAZ file and use this method to trim the data. It may be better as this method puts things on a grid rather than the haphazard trimming in the import LAZ routine.