Tag, You’re It - Physical Tracking Tech, Defense, and How to DIY Your Own

The talk starts with a survival-planning question: how would you navigate back to base in a grid-down scenario where GPS satellites are gone? That led the speaker's team to explore LoRa mesh radio as an off-grid tracker. Before the prototype, the speaker surveys the history of physical tracking, from IFF transponders and early ground-based navigation to today's AirTags, Tile trackers, cheap OBD-II and GPS units, and LoRa asset systems already used in warehouses. The case against commercial trackers rests on corporate server logging and their failure without cellular or Bluetooth coverage.

The middle section covers defenses and the team's build attempts. Phone alerts and the third-party AirGuard app catch some unwanted trackers, while physical sweeps, SDR scanning near 925 MHz, thermal imaging and nonlinear junction detectors cover the higher end, though the last are costly. The two-antenna timing approach failed, and a room of ESP-NOW receivers using weighted-centroid math kept placing the target in the middle. Body interference and the need to recalibrate for each room made the design messy.

The closing points are practical. LoRa can reach hundreds of meters in dense urban areas and kilometers in ideal conditions, which suits kids, dogs, backcountry use and subterranean sites. The speaker notes that red teams already use LoRa for persistence, and that a low-duty-cycle beacon is hard to detect. The takeaway is that cheap off-grid tracking is feasible, and that defenders need to plan for it.