Calibration of vessel mounted LiDAR

This paper investigates the problem of latency estimation between an IMU (Inertial Motion Unit) and a LiDAR (Light Detection And Ranging). The latency is due to the IMU itself, but also to the acquisition software and hardware configuration, which is generally set-up by survey systems users. We propose a method for latency estimation, and we show that this method meets the accuracy requirements of most LiDAR survey applications. We present test results of our method on various acquisition systems and hardware configuration which demonstrate that it is able to identify very accurately the total latency through a simple procedure. Our method does not require any positioning device, therefore it is independent of non modeled errors which may corrupt geolocalized data. Our method enable the user to estimate any LiDAR-IMU latency, in order to to optimize the configuration of a kinematic survey system and to enhance its robustness features with respect to high motion dynamics. We also propose a new boresight angle calibration method between LiDAR and IMU, and we estimate its accuracy and precision. As these two methods do not need any positioning data, they avoid the propagation of GPS errors into the calibration procedure.