Two popular techniques Velodyne LiDAR customers use for georeferencing are inertial referencing and SLAM (Self-Localization And Mapping).
Inertial referencing, is the location and orientation of the sensor at every moment with an inertial navigation system (INS). An INS combines a Global Positioning System (GPS) receiver with an inertial measurement unit (IMU). Timestamp data from the INS and LiDAR sensor are time-synchronized to the GPS satellite’s reference clock, allowing the user to match each LiDAR data point with its corresponding position and orientation from the INS. Having matched the LiDAR data with the INS data, each measurement is translated into a single coordinate system.
SLAM is an interpolation technique to georeference an environment. SLAM software identifies stationary objects in the LiDAR data. The algorithm then uses the location of the stationary objects to mathematically back-out the movement of the LiDAR and translate the data into a single coordinate system.