OVERVIEW: The ATC‑1 is an expendable, lightweight, towed acoustic torpedo decoy designed to protect surface ships by simulating false targets for passive and active acoustic-homing torpedoes. Developed by Rafael (Israel), it is deployed from stern launchers to seduce incoming torpedoes away from the ship.

DETAILS: The ATC‑1 is a compact acoustic decoy towed behind a vessel via a cable and contains its own power source to emit strong acoustic signals resembling legitimate ship signatures. It operates independently of the ship’s systems once deployed, producing both passive noise and active acoustic jamming it is officially presented as capable of countering both passive and active homing torpedoes. Originating from Rafael’s countermeasure line, it is part of the ATDS (Advanced Torpedo Defense System) family, including ATC‑2 and torpedo destroyers. While weight and exact acoustic output are proprietary, it is understood to be similar to US AN/SLQ‑25 Nixie but enhanced for both passive and active acoustic decoying.

The “ATC” acronym stands for Acoustic Torpedo Countermeasure, with “‑1” indicating the baseline variant. The modular design allows integration into containerized or hard‑mounted launchers under ATDS, with higher variants (ATC‑2) adding advanced features like deployable sonar and jammer modes.

FUNCTION: After launch, the ATC‑1 is towed behind the ship and emits a strong acoustic signature either mimicking ship propulsion noise or simulating active sonar pings to lure homing torpedoes toward the decoy cable and away from the vessel. It runs on battery power and continues jamming until power depletion or retrieval.

NOTE:
IOC: Unconfirmed; system has been "operational for some time" as of mid‑2010s
Operators: Israel
Platforms: Surface warships equipped with Rafael ATDS modules

SOURCE:
Military Periscope: https://www.militaryperiscope.com/weapons/sensorselectronics/electronic-support-measureselectronic-warfare/atc-1/overview/ ; Bharat‑Rakshak “Modern Torpedoes And Countermeasures” ; Military‑Review “Surface ships: anti‑torpedo defense systems”