In many security and monitoring scenarios, it is not enough to detect that “something is there” – we also need to know where several transmitters are, often at the same time. The new study by Staridas et al. proposes a triangulation-based method that can estimate the position of multiple transmitters using a fixed network of sensors spread over a large area. Instead of relying on expensive hardware that measures distance, the method uses “range-free” sensors, which only need to know the direction of the signal and not how far away it is.

The approach starts from a Fixed Sensor Network, where each sensor knows its own position and the direction (bearing) towards each transmitter it detects. By combining bearings from at least three sensors, the algorithm identifies “triangulation areas” where a transmitter is likely to be located. These areas are then refined using additional processing steps until a precise point can be projected on the map for each transmitter.

This work is highly relevant to UnderSec because it helps address a core challenge in protecting critical and underwater infrastructures: accurately estimating the position of multiple potential sources of interference or threat within a wide area of interest. The method is designed to work in real time, using data transmitted via wireless links, and is compatible with the kind of long-range, direction-only sensing concepts being developed within the project.