Justin Gomez


Education: Bachelor of Science in mechanical engineering (December 2010)

McNair Project: LIDAR Digital Elevation Modeling (2006)

Mentor: Dale Schinstock, Ph.D.

Light detection and ranging (LIDAR) is a method utilizing laser light for remote sensing. One common application of LIDAR is digital elevation modeling. For this project, a LIDAR module was mounted to an unmanned aerial vehicle (UAV) with the intent of generating digital elevation models (DEMs).

In order to generate a DEM, the UAV must be properly equipped with avionics that both determine and log the position and orientation of the aircraft during flight. The avionics must also log the LIDAR-derived distance. Seven pieces of data are collected for each reading: yaw, pitch, roll, altitude, longitude, latitude, and distance. In order to derive a DEM from the raw data, each distance is expressed as a vector in three-dimensional space. This vector is rotated and translated based on the other six pieces of data; this is done for each reading. The result is a collection of points with each point representing an actual point on the Earth's surface. These data can be represented in any coordinate system desired by utilizing additional rotations and translations, and organized into a uniform grid using a simple algorithm.

The results of this project vary based on the quality of the data received. The main problem encountered was the LIDAR module's tendency to interfere with the GPS signal, resulting in numerous false altitude values. Fortunately, these false values were easily detected. The resulting DEM was accurate to within approximately five meters. However, greater accuracy is expected upon further development.