How innocent.....I am amazed how some posters here take things for granted....be it any ASW platform, unless a sub does not give away its position, its very difficult to even detect one (let alone engage it). I am full of smiles when some posters come here with RTS games mentality. A sub is like an covert agent on its own, disconnected from external world when on its task. The general principal states the more noise, the more Chance of it being detected, the more Chance it being engaged, the more Chance it being destroyed. So effectively a sub is itself responsible for its destruction rather than ASW platform
Anti-submarine warfare (ASW, or in older form A/S) is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines.
Successful anti-submarine warfare depends on a mix of sensor and weapon technology, training, experience and luck. Sophisticated sonar equipment for first detecting, then classifying, locating and tracking the target submarine is a key element of ASW. To destroy submarines both the torpedo and mine are used, launched from air, surface and underwater platforms.
My first question is how many of Pakistan's submarine are nucleared powered??
As far as my knowledge is concerned majority are Diseal electric powered one
There are a large number of technologies used in modern anti-submarine warfare:
Sensors
Acoustics particularly in active and passive sonar, sonobuoys and fixed hydrophones and in the reduction of radiated noise.
Pyrotechnics in the use of markers, flares and explosive devices
Searchlights
Radar
Low frequency spread-spectrum electromagnetic surface wave devices
Active spread-spectrum magnetic techniques
Hydrodynamic pressure wave detection
Blue-green laser airborne and satellite LIDAR
Electronic countermeasures and Acoustic Countermeasures such as noisemakers
Passive acoustic countermeasures such as concealment and design of sound-absorbing materials to coat reflecting underwater surfaces
Magnetic anomaly detection (MAD)
Active and (more commonly) passive infra-red detection
In modern times Forward looking infrared (FLIR) detectors have been used to track the large plumes of heat that fast nuclear-powered submarines leave while rising to the surface. FLIR devices are also used to see periscopes or snorkels at night whenever a submariner might be incautious enough to probe the surface.
The active sonar used in such operations is often of "mid-frequency", approximately 3.5 kHz. Because of the quietening of submarines, resulting in shorter passive detection ranges, there has been interest in low frequency active for ocean surveillance. However, there have been protests about the use of medium and low frequency high-powered active sonar because of its effects on whales. Others argue the high power level of some LFA (Low Frequency Active) sonars is actually detrimental to sonar performance in that such sonars are reverberation limited.
Today some nations have seabed listening devices capable of tracking submarines. It is known to be possible to detect man-made marine noises across the southern Indian Ocean from South Africa to New Zealand. Some of the SOSUS arrays have been turned over to civilian use and are now used for marine research.
Well in India's case, there are dedicated military satellite which would help in thermal imaging (if am not wrong), P8 are very much potent anti- sub platform and most importantly indian navy is much more large, well equipted and has that much resources.
Though I must say still tracking a submarine is not a walk in the park, but sure can be tracked...
regards