Roman Forts in the Northern Black Sea Area Through the Lens of Drone-Based Magnetometry

Abstract

Drone-based magnetometry has demonstrated high effectiveness in verifying satellite observations and detecting new archaeological features. In this study, we evaluate its application for archaeological prospection in the Northern Black Sea region, focusing on the previously documented Roman fort Kamianka V and one newly identified fort. DJI Agras T30 drones equipped with SENSYS MagDrone R3 magnetometers were used to survey areas of 14.0 and 1.6 ha on two sites. The magnetometer was suspended on a 2.0-m extension boom to minimize interference from the drone's electronics and to maintain the sensors' altitude of 1.0 m above the ground. The achieved survey accuracy, estimated as ±1.05 nT, enabled reliable detection of ditch structures—key elements of Roman fortifications—based on anomalies ranging from 1 to 12 nT. Comparison with the ground-based magnetometer survey demonstrates a close correspondence in the observed magnetic patterns. The layout of the Kamianka V fort, which is atypical for Roman military architecture, has been confirmed—featuring two internal forts enclosed within a single outer defensive system. The New fort was identified as a square-shaped positive magnetic anomaly consistent with a Roman-period enclosure. The study demonstrates the strong potential of drone-based magnetometry for large-area, high-resolution archaeological mapping in the steppe environment, including the detection of subtle earthen structures often obscured by intensive agricultural land use. These findings contribute to ongoing research on Roman military presence in the Northern Black Sea region and illustrate how drone-based geophysical solutions can expand the spatial and historical understanding of frontier systems.