Improved Terrain Measurement System for Estimation of Global Terrain Features, Surface Roughness, and Texture

Abstract

For decades, the pavement engineering community has continued to drive improvements in accuracy and repeatability of terrain measurement systems. Traditional terrain measurement systems are tailored for a measuring a specific scale and resolution and hence application scope. These systems tend to focus on surface roughness alone and reject either fine macrotexture or large-scale global features. This work proposes a novel improvement to the terrain measurement system, by increasing the capability to measure the terrain surface at a variety of scales. By increasing the scales of measurement, desired aspects of the terrain profile can be accurately obtained for a wide variety of applications without having to omit large-scale features or macrotexture.

In addition to increasing the capabilities of the traditional terrain measurement system, methods for addressing and minimizing sources of error within the system are developed. Major sources of error in terrain measurement systems, which compromise the accuracy and repeatability of the resulting measured terrain, include scanning laser uncertainty, inertial navigation system (INS) uncertainty and drift, triggering and time synchronization, system misalignment, and post-processing errors. These errors are addressed, and an improved Vehicle Terrain Measurement System (VTMS) is proposed. A triggering and time synchronization system is developed and insight into the development of this system for a terrain measurement system is gained. All three scanning lasers are individually assessed for linearity, with sample profiles analyzed for agreement. The improved VTMS represents a significant development in terrain measurement systems.