Step-frequency ground-penetrating-radar array calibration requirements to estimate dielectric properties of pavements

摘要

During the past decade, ground penetrating radar has emerged as a viable non-destructive testing technology for quality control and quality assurance during pavement construction and for the infrastructure subsurface condition assessment. Data are collected with the ground penetrating radar antenna array attached to a vehicle travelling along the road. With ground penetrating radar data, there is a corresponding need to follow strict protocols both in data collection and data processing, especially for antenna arrays. The key to successful data measurements is the application of calibration procedures appropriate to the hardware system, measurement protocols, and desired measurement statistic or parameter. This paper presents four primary calibration procedures required for ground penetrating radar antenna arrays with actual case application using an air-coupled step-frequency ground penetrating radar array. These calibration procedures for a step-frequency ground penetrating radar antenna array are applied to produce the ground penetrating radar signal foundation for estimating the dielectric properties of materials in a layered highway pavement structure. In addition, a complete solution space is required to identify all layer interfaces and buried objects.