Underwater Detection and Tracking Systems

Underwater Detection and Tracking Systems Naval Weapons Systems

Transducer Theory • Transducer: Device for converting electrical energy into mechanical and acoustic energy (oscillation of water molecules through which sound travels)

Basic Sonar Systems • Active • Echo Ranging Systems • Passive • Listening Systems

Advantages & Disadvantages • Limitations of sonar due to physical properties of sound travel in water • Active vs Passive sonar in detection • Active vs Passive sonar in tracking

Searchlight SONAR • SLOW Search • Easily Saturated • Have to TRAIN the transducer • Old Knox class FF’s and before

Scanning Echo Ranging SONAR • 360 degree search on each transmission • Range/Bearing on a number of targets • No Mechanical rotation, electronic • Greater Power

Hydrophones • Lighter than transducers; less power • Designed for reception only • Bearing information only, no range

Other Sonar Equipment • Tactical Towed Array Sonar (TACTAS) • Sonobouys • Passive • Active • Special Purpose • Dipping Sonar • Sound Surveillance System (SOSUS) • VISUAL!

Magnetic Anomaly Detection(MAD) • Principle: A metallic submarine disturbs the magnetic lines of force of the earth • The magnetic distortion or anomaly caused by a submarine below surface can be detected from above submarine • P-3C, SH-60B

Underwater Communications • AN/WQC-2 • Relatively Short Range

Introduction (Platforms) • Surface Ships (DDG, CG, DD, FFG) • Advantages: • more available manpower • greater time on station • variety of detection equipment • variety of available weapons and better fire control systems • ability to operate in foul weather • embarked LAMPS aircraft

Introduction (Platforms) • Surface Ships • Disadvantages: • NOT “in” the submarine’s environment • Relatively Slow • Noisy • ASW prosecution is protracted

Introduction (Platforms) • Aircraft Carriers • Advantages: • Same as for Surface Ships • Disadvantages: • Same as for Surface Ships • Aircraft Carrier is a High Value Unit • Its importance to naval operations requires many assets to be employed to protect it

Introduction (Platforms) • Aircraft (S-3, P-3, SH-60B) • Advantages: • Speed • Ability to deploy sensors over a large area • Surprise through use of passive detection • Not in submarine’s environment • Altitude increases radar horizon

Introduction (Platforms) • Aircraft • Disadvantages: • Low time on station • Limited weapons capacity • Limited range • Vulnerable to weather

Introduction (Platforms) • Submarines • Advantages: • Shares the advantages of the target • passive detection • concealment • less distracted by sound properties of water • Speed vs. Surface Ships • Nuke subs can stay submerged for months

Introduction (Platforms) • Submarines • Disadvantages: • To detect targets, subs must run deep • To communicate, subs must be shallow • Capable of high speed, but at higher noise level • Diesel subs must snorkel to recharge batteries

Questions?

Underwater Detection and Tracking Systems