Akustik Kelautan - Side Scan Sonar

Summary

This video provides an in-depth explanation of site scan sonar technology, exploring its evolution from analog sonar in the 1800s to digital and modern sonar systems. The video covers the components, advantages, and disadvantages of sonar sets, detailing their use in seabed observation and underwater detection. Key points include frequency selection for target detection, the importance of sonar resolution and range, and how various sonar systems are applied in real-world scenarios, such as locating sunken ships. The material also touches on the technical aspects, including the use of dual-frequency systems, and the challenges posed by water column interference.

Takeaways

• 😀 Site scan sonar is a seabed observation tool that emits a horizontal beam of sound waves to detect features like the seabed, underwater structures, and objects.
• 😀 The evolution of sonar technology has progressed from analog sonar (used in submarines to detect objects) to digital sonar (which can identify objects but is susceptible to interference) and now to modern sonar systems using multiple frequencies for better detection.
• 😀 Analog sonar was used from the 1800s to the 1900s in submarines to detect what was in front, behind, or below them, though it couldn’t identify objects in detail.
• 😀 Digital sonar was developed later and is capable of detecting the objects in front of it, similar to how dolphins use sound to detect fish or other objects.
• 😀 The major disadvantage of digital sonar is its vulnerability to interference, as it relies on one frequency, and when that frequency is disrupted, the sonar may not receive the reflected sound waves.
• 😀 Modern sonar systems use multiple frequencies, similar to how bats emit sound waves at various frequencies, which helps to avoid interference and improve detection accuracy.
• 😀 Site scan sonar is typically used to observe underwater environments, and frequencies range from 100 kHz to 1800 kHz depending on the type of sonar.
• 😀 There are different types of sonar systems, including Taufik site scan sonar (pulled) and full-mounted sonar systems (installed at the bottom of the ship).
• 😀 Effective sonar scanning requires careful consideration of target identification, frequency selection, range, and depth to optimize the detection and image quality of the seabed or objects.
• 😀 Sonar scan systems offer dual-frequency capabilities, providing high resolution for short distances and better range for detecting distant objects, though they may have distortion due to environmental factors like ship speed and cable instability.

Q & A

What is site scan sonar and how does it work?

Site scan sonar is a seabed observation tool that emits a horizontal beam of sound waves. It detects parts of the seabed by emitting frequencies ranging from 100 kHz to 1800 kHz, depending on the type of sonar system used.

What is the evolution of sonar technology?

Sonar technology evolved from analog sonar in the 1800s-1900s, which was used in submarines to detect objects. Digital sonar followed, enabling the detection of objects and their types, and the modern sonar system, developed in the 2000s, uses multiple frequencies for clearer detection and less interference.

What are the main types of sonar scan systems?

The main types of sonar scan systems are towed sonar, which is pulled behind the ship, and hull-mounted sonar, which is installed at the bottom of the ship.

How does modern sonar differ from digital sonar?

Modern sonar systems, like bat sonar, use multiple frequencies to detect objects. This allows for better detection even if one frequency is disrupted. Digital sonar, on the other hand, uses a single frequency, making it more susceptible to interference.

What is the role of the water column in sonar scanning?

The water column is an area that cannot be detected by the sonar system. The sonar is unable to capture images of what is directly beneath this column, limiting its ability to scan certain regions.

What is the significance of determining the target before starting the sonar scan?

Determining the target before starting the scan is crucial because it helps guide the sonar settings, such as selecting the appropriate frequency and range to ensure optimal detection and accurate imaging of the desired object.

Why is frequency selection important in sonar scanning?

Frequency selection is important because low frequencies are better for detecting objects at a greater distance but with lower resolution, while high frequencies offer higher resolution but with a limited range. The choice depends on the type of scan and the target distance.

What is the relationship between range and distance in sonar scanning?

The range refers to the distance that the sonar scan can cover, which directly affects how large or small a target appears on the display. For more accurate scanning, the range needs to be adjusted based on the distance to the target.

What is the ideal depth required for sonar scanning?

The ideal depth for a sonar scan is about 10% of the range being scanned. This depth ensures that the sonar can capture a full image, both close and distant objects, with optimal resolution.

What are the advantages and disadvantages of using site scan sonar?

Advantages of site scan sonar include the use of dual frequency systems, high resolution (0.1 m), and fast sonar signal transmission. Disadvantages include potential distortion due to ship speed variations, unstable cables, and the inability to scan areas directly beneath the water column.