Moving LIDAR Data Into Civil 3D- Procedures

As many know LIDAR is growing momentum as a way to create and display data involved in a Civil Engineering project. This data can be very useful, typically in more ways than one; this is just one of the ways that LIDAR can be used in a work environment.

When getting LIDAR Data into Civil 3D the way that is specified in this exercise we must convert a .txt into a .mdb. That way we can link the data into Civil 3D. The following steps in this guide will allow us to use this data in the environment provided by Civil 3D.

1) Converting our .txt into .mdb format

First, we must start Microsoft Access and begin a new file, then we begin to create a new database by selecting the blank database from the New File Task Pane.

Continuing, we must browse to a location of our choice to save this file and name it so that it is familiar to us. Now we are able to click �create� which will generate our database. After we have created this, we will find ourselves in the Database Dialogue Box. We can now right click and Import the database we just created. Once you select �import� the import dialogue box will appear and we can import the .txt that contains our LIDAR data.

Since our data is comma-delimited we will choose the option �Comma Delimited� in our Import Text Wizard in order to define our data, click �finish� and then click �OK.�

We have just finished successfully converting our data into the proper format that makes it possible to use this data in our projects.

2) Setting up our ODBC (Open Database Connectivity) Data source linked to our .mdb file

This section describes how to create an ODBC Data Source in order to link our data into Civil 3D. First we must access our Control Panel and click on the Administrative Tools shortcut. Under this selection you will see an icon for Data Sources (ODBC). We will double-click this to continue.

Under the OBDC Data Source Administrator we will need to add a MS Access Database. Then under the Create New Data Source dialogue box, click on Microsoft Access Driver (.mdb) name, click on finish and the ODBC Microsoft Access Setup dialogue will appear.

In this box we will browse to the .mdb file that was created, select this file and it will return us to the prior box. We will name this database in the Data Source Name box within the Microsoft Access Setup dialogue box. Once this is completed, we will close out of the Admin tools. We have now created an ODBC Data source we will link to inside of Civil 3D.

3) Filtering Data to create a surface.

Now that we have our data source created we can begin to work in our application. We will start by creating a new file, preferably from a template that is set up as your company desires. Once in our drawing, we will need to edit the coordinate settings to complement our LIDAR data. In the prospector tab, we can now create a surface that we will name EG for existing ground and use the style NO BORDER for our display. Now we can add the desired point file to our surface, so under the point file option under definition we will choose to add a point file.

Once we select �add� we will be taken to the Point File Format Dialogue Box. This is where we will edit the format to fit our data. In this case we will select the ENZ (Easting, Northing, Elevation) format and then click copy.

This will take us to where we can edit the format in which the data is read which will allow us to sync with the LIDAR data. In this case we will change the format name to LLZ (Latitude, Longitude, Elevation) Comma Delimited. Now we can choose the frequency that we want to use to filter our LIDAR data. Considering that LIDAR contains an enormous amount of points, we want to filter this data so that it is manageable. This part of the dialogue will allow us to do this. We now toggle the Sample Every checkbox and set the frequency of the point that will be inserted. In our situation we will choose 10 points.

We must now set the Coordinate type in which we will be formatting our points. We will now go into our copied Point file format and change the Easting and Northing Columns to DECDEG Longitude and DECDEG Latitude and we will also change both precision columns to 6.

This enables us to go ahead and choose our source file, click browse next to the Source file field and browse to the location of your saved .txt file, then click OK. This is where the Point file is read into the definition of the surface. Now we can use the Zoom to command to see our surface.

4) Using Map Tools to Attach Data to Surface

Using the Map tools in Civil 3D we can attach this data to the point we have inserted into our surface. We will use the toolspace within the Map functionality to do so. Under the Display Manager tab we will choose to connect to data via the data icon. To the left of the dialogue there will be a section labeled Data Connection by Provider.

This is where we will choose to add an ODBC connection. Once we choose to add we will get the option to name our connection. It would be a good suggestion to name it something similar to all the files associated with the data. Once named, we can choose the source. We will click the ellipsis above the connect icon and choose the name we created for our Access Database. We will now connect the data via the connect button .At this point it will ask for a user name and password. Considering we did not create one you can freely log in without any information. Once in we will have access to our data and we can set the coordinate system we wish to apply to this data in the dialogue.

In our case we will set the data to conform with info we established earlier in the exercise by matching our fields in the data with our X,Y,Z Coordinates, Field 1-X, Field 2-Y, and Field 3-Z. We established these fields when we changed the format to LLZ. Now we can add the data to the map. However, we only want to see a specified area of the surface that we created earlier, so we will add this data with a query that allows us to specify the location in which we can view the LIDAR data. When viewing the Add button you will notice a pull down that will allow us to add to the map with a query. In this instance we will choose the Location property to define our query. In the Location Condition dialogue we will simply choose that we want our data to be applied within a rectangle. We can now define our query. Now we can choose anywhere within the boundary of our surface to attach the LIDAR points and data. You must manipulate the style so that these points become visible. If you select the points and right click and then use the check out feature they will become MAPPOINT Objects. Once exploded the MAPPOINT objects will become AutoCAD point objects with X,Y,Z values, thus allowing you to add the objects to the surface to create a more in-depth surface in a specified area.

In conclusion, using this LIDAR data will allow us to create and utilize information with less manpower to gather and manage all this information that is at our fingertips. This powerful tool will continue to grow, considering its accessibility within the civil engineering world. It is an accurate, manageable, new and powerful way to get faster data without sacrificing accuracy.