SONAR
What Is SONAR?
SONAR (Sound Navigation And Ranging; Turkish: sonar) is a system that detects the position and condition of submerged objects using acoustic waves. It is the primary sensor for underwater detection — used by submarines, surface ships, maritime patrol aircraft, and helicopters to locate, track, and engage underwater contacts (submarines, mines, divers, UUVs).
Types of SONAR
- Active sonar: transmits an acoustic ping and listens for the echo — gives range, bearing, and depth; but reveals the emitter’s position
- Passive sonar: listens only — detects propulsion and machinery noise; covert; limited to bearing only (no range)
- Hull-mounted sonar (HMS): fixed array in ship’s keel — suited for medium-frequency active/passive
- Towed array sonar (TAS): long hydrophone array towed behind ship — very low frequency, long range
- Variable-depth sonar (VDS): lowers sonar below thermal layer for better detection
- Dipping sonar: helicopter-lowered active/passive sonar for ASW search
- Sonobuoys: air-dropped expendable passive/active sonar sensors
SONAR in Türkiye
ASELSAN developed the ZARGANA hull-mounted sonar for the Turkish Navy’s MİLGEM corvettes and İSTİF frigates — the first domestically produced Turkish naval sonar. ASELSAN is also developing towed array and variable-depth sonar systems to complete Türkiye’s indigenous ASW sensor suite. Previously, Turkish warships relied entirely on foreign (US, German) sonar systems; ZARGANA marks a significant step toward ASW self-sufficiency.
Frequently Asked Questions
What is sonar?
A system using acoustic waves to detect and locate underwater objects — the primary underwater detection sensor for navies worldwide.
What is the difference between active and passive sonar?
Active sonar pings and listens for echoes (range and bearing); passive sonar only listens to ambient noise (bearing only, but covert).
What is Türkiye’s domestically produced sonar?
ASELSAN’s ZARGANA hull-mounted sonar — installed on MİLGEM corvettes and İSTİF frigates.
Source: SSB Defense Industry 360 Glossary of Terms.
