This compendium is a compilation of technical articles on GPR published in ASNT's Materials Evaluation, Research in Nondestructive Evaluation, and The NDT Technician newsletter from 1999 through 2015. It was compiled at the request of the Ground Penetrating Radar Committee of the ASNT Technical and Education Council in order to provide reference material for the development of the GPR body of knowledge included in ANSI/ASNT CP-105 (2016). The research and findings contained herein offer real-world and laboratory tested insight into the field of GPR and can be useful to a diverse readership. For students, this guide is an invaluable tool toward a greater understanding and overall knowledge of GPR. For the seasoned technician, the compendium serves as a reference that documents articles on the method. ISBN: 978-1-57117-370-6