Evaluation of a steerable 3D laser scanner using a double Risley prism pair

Abstract

Laser scanners based on Risley prism pair technology offer several advantages, including a multitude of scan pattern generation, non-overlapping patterns, and a conical Field-Of-View (FOV) generating a high data density around the center. The geometry and material properties of the prisms define the conical FOV of the sensor, which can be typically set between 15° to 120°. However, once the prisms are defined, the FOV cannot be changed. Neptec Technologies in collaboration with Defence Research and Development Canada has developed a unique scanner prototype using two pairs of Risley prisms. The first pair defines a small 30° FOV which is then steered into a larger 90° Field-Of-Regard (FOR) by using the second pair of prisms. This presents the advantages of a high-resolution scan pattern footprint that can be steered quickly and randomly into a larger area, eliminating the need for mechanical steering equipment. The OPAL Double Risley Pairs (DRP) prototype was recently evaluated at Yuma Proving Ground with the scanner positioned atop a tower and overlooking various types of targets while dust was generated by a helicopter. Results will be presented in clear and dusty conditions, showing examples of moving a high resolution FOV within the FOR.