Study on the maximum penetration depth of GPR based on soil electromagnetic properties

Precise estimation of Ground Penetrating Radar (GPR) maximum penetration depth is essential for underground engineering design and evaluation. This study utilizes a time-domain ultra-wideband (UWB) measurement system and reflectometer to characterize soil electromagnetic properties from diverse Chinese geographical regions. Electromagnetic parameters (electrical conductivity, complex permittivity) were measured across 300 MHz–4 GHz. The correlation between soil moisture content and electrical conductivity was analyzed, alongside variation patterns of soil electromagnetic properties to elucidate their mechanisms. Comparative analysis with the World Soil Database shows transitions from arid to humid conditions increase soil moisture content by 2.7×, the real part of complex permittivity by 1.58×, and electrical conductivity by 1.33×. Additionally, greater soil depth enhances moisture content, dielectric constant, and electrical conductivity. High electrical conductivity causes significant electromagnetic wave attenuation, reducing radar penetration depth. To mitigate this, a transfer matrix method-based algorithm was developed, demonstrating superior performance over existing models and reliable penetration depth estimates for diverse soil conditions.