IAS Gyan

Daily News Analysis


3rd October, 2023 Security

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  • The Indian Navy is planning to enhance its maritime surveillance and anti-submarine warfare capabilities by equipping the MQ-9B Sea Guardian medium altitude long-endurance (MALE) drones with sonobuoys.


  • Sonobuoys are small, expendable devices used in underwater acoustics and sonar systems for detecting and analyzing sound in the ocean, especially for tracking submarines and other underwater objects.


  • Sonobuoys are deployed by dropping them into the ocean from aircraft or launching them from ships or submarines.
  • They sink to a predetermined depth and begin listening for acoustic signals to pinpoint potential submarine threats.
  • Multiple sonobuoys can be deployed in a pattern to determine the exact location of a target.


  • Passive Sonobuoys: Quietly listen for and record sounds without emitting any signals. They use hydrophones to listen for sound energy from a target.
  • Active Sonobuoys: Emit a sound pulse and analyze the return signals (echoes) to detect and locate targets. They use transducers to send an acoustic signal.
  • Special Purpose Buoys: Provide information about the environment, such as water temperature, ambient noise level, etc.


  • A typical sonobuoy consists of a cylindrical or spherical buoyant housing.
  • Sensors for detecting acoustic signals.
  • A battery or power source.
  • A radio transmitter or other communication system to relay data to the host platform (e.g., aircraft or ship).

Other Applications

  • In addition to anti-submarine warfare, sonobuoys are used for scientific research and environmental studies, including studying the behavior of whales and other marine creatures.

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MQ-9 Reaper (Predator B)

  • Developed by General Atomics Aeronautical Systems (GA-ASI), primarily for the United States Air Force (USAF).
  • It's designed for long-endurance, high-altitude surveillance.
  • Larger, heavier, and more capable than the MQ-1 Predator.
  • Can be controlled by the same ground systems.

MQ-9B SkyGuardian

  • Next-generation remotely piloted aircraft systems (RPAS).
  • Provides persistent intelligence, surveillance, and reconnaissance (ISR) capabilities worldwide.

MQ-9B SeaGuardian

  • Maritime-focused variant of the SkyGuardian RPAS.
  • Integrates advanced maritime intelligence, surveillance, and reconnaissance (ISR) capabilities.
  • Enables real-time search and patrol above and below the ocean's surface.

Integration Benefits

  • Submarine Detection
    • Extends reach and surveillance capabilities.
    • Deploys sonobuoys over a wide area for detecting submerged threats.
  • Extended Range
    • Long endurance and high altitude cover large ocean areas efficiently.
    • Expands coverage range for monitoring and responding to potential threats.
  • Real-time Data
    • Acoustic signals detected by sonobuoys transmitted in real-time.
    • Enables rapid decision-making and response to submarine threats.
  • Versatility
    • Choice of passive and active sonobuoys.
    • Passive for discreet listening, active for active searching and locating.
  • Environmental Data
    • Provides valuable environmental information (e.g., water temperature, noise levels).
    • Enhances understanding of the underwater environment.
  • Cost-effective Surveillance
    • Drones deploy sonobuoys, reducing the need for expensive manned assets.
    • Offers persistent and cost-effective maritime surveillance.
  • Safety
    • Reduces risks associated with manned aircraft deployments.
    • Offers safer and more flexible deployment options.


Integrating sonobuoys with MQ-9B Sea Guardian drones significantly enhances the Indian Navy's maritime surveillance and anti-submarine warfare capabilities. This integration provides a valuable tool for safeguarding maritime interests and ensuring regional security.


Q. Which type of sonobuoy emits a sound pulse to detect and locate targets?

a. Passive Sonobuoys

b. Special Purpose Buoys

c. Active Sonobuoys

d. Environmental Buoys

Answer: c.