SubMon

Mine subsidence monitoring through precision computer vision

SubMon is Deftec's camera-based structural displacement monitoring platform designed specifically for detecting and measuring tower tilt and subsidence caused by underground mining activity. It uses advanced computer vision with ArUco marker detection to achieve sub-pixel accuracy measurements at unattended mine sites — replacing manual survey rounds with continuous, automated monitoring.

Edge capture devices deployed at each monitoring location automatically photograph ArUco markers mounted on transmission towers every 15 minutes, uploading frames over cellular connectivity to the cloud processing pipeline. The pipeline performs quality assessment, marker detection, reference marker homography registration, and tower displacement measurement — all within the ingest path. Reference markers on geotechnically stable ground correct for camera movement caused by wind and thermal expansion.

The real-time dashboard displays displacement trends, frame history, target measurements, and camera health across all monitored sites. Configurable threshold-based and rate-of-change alerts notify operators via email when displacement exceeds acceptable limits, enabling early intervention before infrastructure is compromised. All measurements are recorded in both pixel and real-world millimetre units with temporal smoothing filters.

SubMon supports multi-site deployments with organisation-scoped access control. Edge devices authenticate via secure device keys, while users authenticate through Microsoft Entra External ID. The platform runs on Azure cloud infrastructure with PostgreSQL for measurement storage, blob storage for captured frames, and Cloudflare Pages for the web dashboard.