Detection and Mapping of Specular Surfaces Using Multibounce Lidar Returns

TL;DR

This paper introduces methods to detect and map specular surfaces using multibounce lidar returns, enabling visualization of surfaces invisible to traditional single-scatter lidar systems, including transparent surfaces.

Contribution

It develops mathematical expressions linking multibounce lidar signals to specular surface geometry and proposes techniques for their retrieval in various scanning scenarios.

Findings

Effective detection of specular surfaces using multibounce lidar.

Ability to map transparent and hidden surfaces.

Enhanced scene understanding with specular surface mapping.

Abstract

We propose methods that use specular, multibounce lidar returns to detect and map specular surfaces that might be invisible to conventional lidar systems that rely on direct, single-scatter returns. We derive expressions that relate the time- and angle-of-arrival of these multibounce returns to scattering points on the specular surface, and then use these expressions to formulate techniques for retrieving specular surface geometry when the scene is scanned by a single beam or illuminated with a multi-beam flash. We also consider the special case of transparent specular surfaces, for which surface reflections can be mixed together with light that scatters off of objects lying behind the surface.