LiGeoreference is a LiDAR point cloud georeferencing software developed independently by GreenValley International which allows users to merge range measurements collected by mobile, UAV or airborne laser scanning systems with position and orientation information recorded by integrated IMU and GNSS sensors. This flexible software solution outputs 3D point clouds in .las and .LiData file formats (LiData file format can be opened in GreenValley International’s LiDAR360 software instantly) with LiDAR returns mapped to a user-specified datum, including WGS84, projection, and coordinate system (e.g. UTM). Point clouds can also be attributed with RGB imagery using LiGeoreference’s data fusion capabilities to produce a true-color 3D model of an object or area surveyed. LiGeoreference can transform and process data collected by Riegl, Velodyne and other widely-used laser scanning technologies. LiGeoreference is now available as a stand-alone application with a helpful graphical user interface as well as a command-line interface for scripting and easy integration with third party software.
LiDAR technologies exploit the relationship between light’s constant velocity and time to produce highly accurate and precise measurements of variable distances or ranges. Remote-sensing systems used to generate LiDAR data emit infrared and/or visible wavelengths of electromagnetic energy from an optically-focused laser in short bursts or pulses that are then returned to the broadcasting unit’s integrated photon sensors by signal-reflecting objects. The laser pulse returns are then accurately mapped to 3D space by merging the LiDAR data with information from inertial measurement units (IMU), which determine a LiDAR sensor’s orientation about the X, Y and Z axes. These orientations are also typically referred to as the roll, the pitch, and the yaw or heading angles, respectively. External and/or internal GNSS equipment can also be used to determine the geographic locations of the LiDAR system as it collects data. During post-processing, information from the LiDAR sensor, or laser scanner, the IMU, and the GNSS systems must be methodically merged to determine the trajectories of the 3D mapping system while it moved about the survey area collecting data. This is a critical step in producing accurate datasets from laser scanning systems mounted on mobile, UAV, or airborne platforms.