Get acquainted with the new effective equipment in the package
Recognizing the new importance of anti-submarine warfare, the industry has begun installing sonobuoy pods onto a variety of unmanned platforms, including MQ-4C Tritons, MQ-8C Fire Scouts and MQ -9 Reapers. F-35 Lightings, F/A-18 Super Hornets, and MQ-25 Stingrays should also carry pods such as the L3 Harris Sonobuoy Distributor System (SDS), but just as importantly, they carry sonobuoys form payload far greater than existing inventory capabilities. Existing sonobuoys do not move with targets, and environmental conditions rarely support detection ranges that may exceed a few thousand yards. Therefore, traditional airborne anti-submarine platforms must constantly place sonobuoys in front of evading submarines to create attack solutions. On the other hand, a payload in the form of a mobile sonar buoy can automatically detect, identify and track target submarines within hours.
Researchers at Stanford University's Office of Naval Research recently conducted a laboratory demonstration using a drone in the form of a sonobuoy (UAV) to track an underwater submarine from the air. Known as photoacoustic airborne sonar systems (PASS), these low-flying drones use lasers to evaporate water near the surface, producing underwater sound that travels like any other sonar. The drone also carries an array of capacitive micromachined ultrasound transducers (CMUTs) sensitive enough to detect sonar echoes that pass through the water vapor barrier. Swarms of airborne sonar sensors can work together to search the area and then track any detected submarines. Adding magnetic anomaly detectors to these drones could provide further confirmation that the detected objects were submarines and not whales.
Tactical environmental conditions with a thermocline may trap these sounds in surface or mixed layer channels and prevent them from reaching deeper targets. However, this acoustic reality applies to any water-based sonar, not just photoacoustic airborne sonar systems. Installing a mobile sensor beneath this layer would complement these photoacoustic airborne sonar systems for drones, giving target submarines nowhere to hide.
Like smaller, slower, and cheaper torpedoes, unmanned underwater vehicles (UUVs) deployed from sonobuoy tubes can help see beneath this acoustic layer. The Mk-39 Expendable Mobile Anti-Submarine Training Target (EMATT) has been an affordable target for decades. Matching components of this proven system with a low-cost active sonar system, possibly using a capacitive micromachined ultrasonic transducer array, would provide the ASW crew with a mobile and autonomous acoustic sensor. Changes in the sensor's sonar emissions, such as changes in the chirp curve or pulse repetition frequency, will alert other sensors, listening crews, and unmanned underwater vehicles that something is worth tracking.
Finally, air-launched mid-to-high-altitude drones would allow aircraft with limited fuel to depart from distant targets after deploying weapons and sensors. These loitering UAVs will receive, bundle, and retransmit signals from the Airborne Optoacoustic Airborne Sonar System UAV and sonobuoy combination back to the carrier strike group, allowing ASW aircrews to operate within manned aircraft coverage Continue tracking the target during the gap. While this air-launched drone can be launched from a sonobuoy tube, a larger drone deployed from a bomb rack would allow for longer cruise times. This aerial drone will also help connect distributed acoustic sensors into new multistatic sonar systems.
Bringing multi-state sensors to the edge
As with most acoustic anti-submarine systems today, photoacoustic airborne sonar systems, unmanned aerial vehicles and unmanned underwater vehicles based on expendable mobile anti-submarine training targets use bistatic sonar. , and equipped with a transmitter and receiver. While these tools will aid in long-range anti-submarine warfare, the Navy should also connect many other individual acoustic sensors (new and old) into the multi-base sonar system architecture to further improve search and localization.Unlike bistatic sensors, which have a single sensor, any receiver in a multistatic system can process the echo generated by any transmitter in the network, and by comparing the return signals, the system can generate a target trajectory. Serbian forces claimed that in 1999 they detected and shot down an F-117 Nighthawk using multi-base radar . The P-8A Poseidon already utilizes multi-base active coherence capabilities, equipped with specialized SSQ-125 sonobuoys and a powerful open-architecture sonar processing suite.
Continued advances in computing efficiency and capabilities have facilitated edge processing, where most data is processed on the device rather than on a central server (like the one on the P-8A). This basic system architecture is the foundation for IoT and 5G, but it may also unlock widespread use of multi-base sonar across platforms.
A cycle of this edge-processed multistatic sonar will begin with a network "standby" message, pre-announcement of the location, depth, acoustic profile and timing of the echo to be processed. Distributed acoustic sensors in the network will then listen - first for the transmitted sound, then for any echoes. Each networked sensor, whether a passive sonobuoy, active sonobuoy, unmanned surface vessel or other sensor, processes these sonar echoes locally and then broadcasts its calculated target position and the strength and direction of the echo. and doppler shift . This edge-processed, multi-base sonar network will create a more complete acoustic picture, accelerating the location and destruction of threatening submarines. The
edge processing model will also enable the sensor to passively listen for frequencies of interest and only send alert messages when these frequencies are heard. Although passive detection is less useful than multi-base active sonar for nearly silent diesel submarines drifting on batteries, it is still important for the noisier nuclear submarine . The edge processing model will also help preserve sensor battery life for active and passive sonobuoys by reducing radio and sonar transmissions. Alternatively, shrinking the batteries would allow each launch platform to carry more sonobuoys while still maintaining acceptable buoy lifespan. However implemented, the payload, not the platform, will define the future of anti-submarine warfare.
Attack (Do Not Track)
F/A-18, F-35 and MQ-25 require weapons to threaten submarines with rapid attack and to conduct effective attacks as needed. In the near future, the U.S. Navy should test-fly existing Mk-54 lightweight torpedoes for these aircraft, ideally equipped with a High Altitude Anti-Submarine Warfare Capability (HAAWC) guidance fin package. The same applies to the Compact Rapid Attack Weapon (CRAW), which weighs slightly more than the AIM-9X and could provide these aircraft with a capable anti-submarine weapon for routine carry.
These existing torpedoes have one major limitation: quantity. The Navy's inventory of lightweight torpedoes is limited, as is the space in shipboard magazines to store these highly volatile chemical-fueled weapons.
The navy can create affordable and almost unlimited anti-submarine smart weapons by modifying simple depth bombs . According to the basic configuration of the Quickstrike air-dropped mine, this new depth bomb will use any Mk-80 series bomb , a high-drag parachute tail device and an underwater proximity fuze installed in the rear fuse well. Capacitive micromachined ultrasound transducers also support photoacoustic airborne sonar system technology and will allow for low-cost, high-reliability sonar sensors. The impact of the water will cut off the tail unit and the fuze will then deploy a stable omnidirectional sonar sensor as it falls into the water. Depth charges will be detonated upon passing the closest approach point to the target submarine to maximize damage. The aircraft carrier's ammunition magazine can store thousands of these fuses, ready to convert any Mk-80 series bomb into an instant anti-submarine weapon.
tag and release
Finally, while the Navy needs more and better anti-submarine weapons to attack threatening submarines, it also needs better anti-submarine tools to manage the escalation of conflicts outside of armed conflict. During the Cold War , NATO anti-submarine warfare forces tested a large number of magnetic noise generators dropped on Soviet submarines, and used training depth charges to warn Soviet submarines during the Cuban Missile Crisis .
Updating magnetic noise generators into low-cost and expendable command-activated acoustic beacons could help avoid this dangerous chaos in future crises while providing a tactical advantage should a crisis turn into war. These can be deployed from repurposed Rockeye cluster munition dispensers, sonobuoy-shaped dispensers, or more precisely from the aforementioned unmanned underwater vehicles.
No emerging technology or new tactic can solve the challenge of long-range submarine-launched anti-ship cruise missiles. Anti-submarine warfare platforms must not only detect the launch, but also reach the launch point in time to counterattack it. The speed and range of fixed-wing carrier-based aircraft equipped with sonobuoy launchers, mobile sensors and advanced anti-submarine weapons could help restore much of the S-3 Viking's capabilities. Integrating a variety of emerging tools and technologies into new warfighting concepts can do this and more. (End)
