↩ Overview

Derived application — coastal telemetry observatory

Same hardware, a second job. The perimeter modules already listen on hydrophones, so they can double as an acoustic-telemetry receiver array. During an interposition, the sub-drone can dart a tag onto the shark; from then on the network re-identifies that individual by ID at every pass — turning anonymous presence into a daily activity record a public manager can act on, upstream of the protected zone and without harming the animal. Telemetry only sees tagged sharks, so it complements — never replaces — primary detection.

The five perimeter modules double as an acoustic-telemetry receiver array. A shark tagged by the sub-drone is re-identified by ID at each pass (shown here on Monday, Tuesday and Wednesday at neighbouring modules), revealing a late-afternoon recurring pattern. Telemetry reception reaches roughly 300 to 1000 metres, flagging the individual before it approaches; it only detects tagged sharks and complements primary detection.

detection (low) detection (high) telemetry tag / reception re-identification link
#A-217tagged individual
re-identified at each pass
Mon 17:10Detected at the front-left module — passage logged by ID
Tue 18:25Detected at the front-right module
Wed 17:40Detected at the front-centre module — flagged upstream, before approach

What the network now knows

Pattern: late-afternoon, flood tide — a recurring visitor, not a one-off.

Upstream: a receiver reads the tag at several hundred metres, before the shark reaches the protected zone.

Learning loop: the tag gives a ground-truth identity that helps calibrate the primary detector.

HowModules double as acoustic-telemetry receivers (~69 kHz). The sub-drone darts a tag during interposition; every later pass is logged by ID → a daily activity map for managers, kept non-lethal by design.

Only tagged sharks are seen. Telemetry complements — it never replaces — primary detection, which must stay exhaustive and tag-independent. A detection signals presence, not intent.