Reflection waveforms occurring in bistatic radar testing of columns and tree trunks

•Bistatic radar system analysis.•Analysis of radar wave propagation in cylinders.•Numerical, laboratory and real radar data.•Tree trunk and concrete column analysis. Ground-penetrating radar is a non-destructive inspection device which is not often applied to cylindrical media. In this paper, we extend our previous analyses of monostatic GPR waveforms to two bistatic radar configurations for cylindrical objects: 1) Single-offset radar system, where two antennas are simultaneously rotating around the cylinder, 2) multi-offset radar system, where only a receiving antenna is rotating around it. Analyses were performed through numerical experiments with gprMax2D, straight-ray analytical solutions, laboratory and real case studies. The complex real case studies highlighted the benefit of combining bistatic and monostatic radar data acquisitions to better resolve unknown internal structures.