Shielded loaded bowtie antenna incorporating the presence of paving structure for improved GPR pipe detection

• We report on our GPR test site where we buried different pipes and cables.
• We illustrate the effect of paving structure on GPR measurements.
• We demonstrate optimization and shielding of our loaded bowtie antenna.
• Optimization is done by means of an appropriate simulation model of our GPR test site.
• We demonstrate different radargrams recorded on our GPR test site.

In civil engineering Ground Penetrating Radar becomes more and more a considerable tool for nondestructive testing and exploration of the underground. For example, the detection of existence of utilization pipe networks prior to construction works or detection of damaged spot beneath a paved street is a highly advantageous application. However, different surface conditions as well as ground bounce reflection and antenna cross-talk may seriously affect the detection capability of the entire radar system. Therefore, proper antenna design is an essential part in order to obtain radar data of high quality.In this paper we redesign a given loaded bowtie antenna in order to reduce strong and unwanted signal contributions such as ground bounce reflection and antenna cross-talk. During the optimization process we also review all parameters of our existing antenna in order to maximize energy transfer into ground. The entire process incorporating appropriate simulations along with running measurements on our GPR test site where we buried different types of pipes and cables for testing and developing radar hardware and software algorithms under quasi-real conditions is described in this paper.