Ground Penetrating Radar (GPR) has emerged as a powerful and versatile tool for non-invasive subsurface investigation in various fields such as geophysics, environmental monitoring, detection of municipal underground infrastructure, exploration of planetary subsurface structures, archaeology, and more. Recent advancements in technology have led to the development of mechanisms and data processing techniques that enhance the capabilities of GPR systems. This special issue aims to bring together researchers, scientists, and practitioners to share and discuss the latest developments in new GPR mechanism, innovative signal processing techniques, Machine Learning and Artificial Intelligence for GPR data, and so on.