AIRBORN LIDAR

LIDAR is an active sensing system. It is the science of using a laser to measure distance to specific points. It uses its own energy source, not reflected natural or naturally emitted radiation. It can be operated day or night and it is capable of collecting millions of elevation points per hour - much faster than traditional methods. The technology produces datasets with much greater density than traditional mapping. A vertical accuracy for commercial applications of 15 cm is developed on discrete points and supported by rigorous QA/QC. LIDAR operational theory is based on the speed of light and the time it takes for a pulse of light to reach a target and return. Precise time is essential. The reflection of that pulse is detected and the precise time is recorded. Using the constant speed of light, the delay can be converted into a slant range distance. Knowing the position and orientation of the sensor, the XYZ coordinate of the reflective surface can be calculated. Several recent, enabling technological advances have made LIDAR possible. Airborne GPS, which is a satellite-based radio-navigation system put in place by the U.S. Department of Defense. Before flight and data acquisition, all airborne GPS reference base stations identified for use in controlling the project are submitted to the client for review and approval. Typically, a single base station is required to cover a 25-mile flight radius. The base station points selected are typically High Accuracy Reference Network (HARN) or other blue booked National Geodetic Survey (NGS) control points. Base stations are established on these points before any airborne data collection. GPS position data will be recorded at one-second intervals, or epochs, throughout the entire mission. This uses triangulation from multiple satellites to provide accurate positioning. An Inertial Measurement Unit (IMU) is a combination of gyros and accelerometers, typically integrated with GPS systems. Positional accuracies of 18-25 arc-seconds (0.005-deg for pitch and roll, 0.01-deg for yaw) are routinely obtainable.

21403 Timber Pines Dr

Spring, texas 77388

271-907-0671