Advanced GPR Data Interpretation for the Diagnostic of Buried Historical Road Tracks: Case Studies from Ancient Rome

Historic roads are integral to the cultural and visual heritage of landscapes, reflecting the historical narratives of the regions they served. Mapping the planimetric and altimetric geometry of these routes provides insights into past human interactions and supports applications such as sustainable tourism and “slow mobility” [1]. However, detecting buried historical tracks remains challenging due to heterogeneous subsurface conditions and complex electromagnetic wave propagation. In common-offset Ground Penetrating Radar (GPR) surveys, the absence of a reliable velocity model introduces significant uncertainty, often resulting in ambiguous radargrams where meaningful features are difficult to distinguish from noise [2].

To address these challenges, this study proposes a scalable diagnostic framework for the interpretation of buried infrastructure. The methodology extends conventional time-domain analysis by applying Short-Time Fourier Transform (STFT) to obtain localised spectral representations of GPR signals. Key attributes, including central frequency and spectral energy are extracted to characterise material-dependent responses that are not evident in raw data.

The novelty of the approach lies in its ability to provide a systematic and transferable workflow that enhances interpretability without requiring detailed velocity models, making it suitable for complex and heterogeneous environments.

The framework is validated through archaeological case studies in Rome, including investigations at Villa dei Sette Bassi, where historical evidence suggests the presence of previously undocumented road connections. The results demonstrate clearer delineation of subsurface features, enhanced contrast between archaeological remains and surrounding materials, and improved discrimination between structural responses and noise.

These findings highlight the potential of frequency-domain GPR analysis as a robust and objective approach for reducing interpretational ambiguity in the detection of buried historical road networks.

References

[1] de Soto, P., Pažout, A., Brughmans, T. et al. Itiner-e: A high-resolution dataset of roads of the Roman Empire. Sci Data 12, 1731 (2025).

[2] Conyers, L. B. (2016). Ground-penetrating Radar for Geoarchaeology. John Wiley & Sons.