Lab 5

Goal and Background:
The main goal of this lab is to learn basic LIDAR data structure and processing. We will work with processing of various surface and terrain models and creating intensity images and other derivative products from point cloud. This will all be very useful knowledge since LIDAR is really growing exponentially as an subset of remote sensing.

Methods:
To start our lab we first had to import all the LAS data. We first viewed the dataset in ERDAS and then opened ArcMap so we could generate our own LAS dataset. This was an easy task as we just needed to select all the LAS files and import them together. We then ran statistics so we could get our Min Z and Max Z. Then we needed to assign the dataset a XY coordinate system as well as a vertical coordinate system, both of which were in feet. Now we were able to look at a variety of filters such as elevation, aspect, slope, and contour.

We then went to make our DSM and DTM as well as hillshades for both. The DSM and DTM were made through the LAS Dataset to Raster tool. Once we had each of those rasters we could create a hillshade from them that would give us a good interpretation of the surface and terrain from shading.

Now we moved to creating an intensity image. This involved the same steps and tool but this time we switched the field to INTESITY. The output image was really dark so we had to export it as a TIFF so we could view it in ERDAS.

Results:

Hillshade created from the Digital Terrain Model raster.

Intensity image viewed from ERDAS Imagine.

Conclusion:
This lab was a great learning experience as we got our first exposure to LIDAR point data which is a very powerful dataset. From this dataset we can create many different rasters images that we could then analyze even further. Some examples would be Hillshade, Slope, and Aspect. This could then be used as tools when interpreting a landscape or while studying it. The most complex part of all of this is the actual data collection and once that is done and the vendor has went through all the data, LIDAR point data can be used for many many things.