A Deep Dive into Bathymetry Surveys with Echo Sounders and Sonars

Echo sounders and sonars help us navigate and understand the depths. Whether you're navigating with multibeam precision or streamlining surveys with singlebeam simplicity, this guide explains the features and applications of industry-leading echo sounders, guiding informed decisions for your underwater projects.

Multibeam Echo Sounders (MBES):

Multibeam echo sounders work by emitting multiple sonar beams simultaneously in a fan-shaped pattern. The resulting collected data allows for a detailed and efficient survey of the seafloor, capturing a wide area with high resolution. Here are some advantages that multibeam echo sounders offer, such as the Apache 6:

Efficiency in Mapping: Multibeam systems can cover a wide area of the seafloor in a single pass, providing high-resolution, detailed maps efficiently.

3D Mapping: Multibeam sonar technology allows for the creation of three-dimensional maps, offering a comprehensive view of underwater terrain.

Deep Water Exploration: Multibeam systems are effective in deep-water environments, making them suitable for offshore surveys and deep-sea exploration.

Applications:

Seafloor Mapping: Ideal for detailed mapping of large underwater areas, including bathymetric surveys, geological studies, and habitat mapping.

Pipeline and Cable Route Surveys: Efficiently surveys and maps the seafloor to plan and maintain underwater infrastructure.

Singlebeam Echo Sounders (SBES):

Singlebeam echosounders emit a single sonar beam directly beneath the vessel. By measuring the time it takes for the echo to return, the device calculates the water depth. SBES offer the following benefits:

Cost-Effectiveness: Singlebeam systems are generally more cost-effective, making them suitable for projects with budget constraints.

Simplicity in Operation: Singlebeam USVs are simpler to operate and require less training, making them accessible to users with varying levels of experience.

Shallow Water Proficiency: Effective in shallow water environments, such as coastal areas, river surveys, and nearshore applications.

Applications:

Basic Hydrographic Surveys: Suitable for projects where a targeted approach to depth measurement is sufficient, such as shallow water bathymetric mapping and navigation chart updates.

Quick and Uncomplicated Surveys: Well-suited for projects that require rapid deployment and straightforward data collection.

Understanding Echo Sounder Features

The EchoLogger ECT D052S is a high-quality dual-frequency echo sounder designed for precise underwater mapping and exploration. Key features include:

1. Dual-Frequency Operation: Allows users to choose between two frequencies (50 KHz and 200 KHz) based on specific mapping needs. Lower frequencies penetrate deeper waters, while higher frequencies provide finer detail in shallower areas.

2. Tilt and Temperature Sensor: Provides additional data beyond depth measurements. The tilt sensor indicates the angle at which the echo sounder is positioned, aiding in the interpretation of spatial data. The temperature sensor records water temperature, contributing to a more comprehensive understanding of the underwater environment.

3. Comprehensive Package: Ensures users have all necessary components for successful underwater mapping. The durable harness, housing, and mountings collectively contribute to the system's reliability and ease of use.

4. Compatibility with DJI Drones: Enables integration with DJI drones, specifically the M350 RTK model. This compatibility extends the applicability of the echo sounder, allowing for aerial surveys and mapping, enhancing versatility.

5. High-Quality Construction: Enhances durability and longevity, ensuring the echo sounder can withstand challenging conditions encountered in underwater environments. High-quality construction contributes to the reliability of the tool.

6. Cable Length: 2.5m: Provides a 2.5-meter cable for flexibility in deploying the echo sounder in various underwater scenarios, ensuring sufficient reach while maintaining practicality.

The Apache 3 USV offers unmanned operation solutions for hydrologists and come equipped with a suite of features such as:

1. Single Beam Echo Sounder Included: The Apache 3 is equipped with a single beam echo sounder. It emits a single sonar beam directly beneath the vessel, allowing for straightforward depth measurements.

2. Detection Range: 0.15 m to 200 m: Indicates the range over which the echo sounder can effectively detect underwater objects or the seafloor. In this case, it can measure depths ranging from 0.15 meters to 200 meters.

3. Resolution: 0.01 m: Represents the smallest change in depth that the echo sounder can detect. A resolution of 0.01 meters ensures precise measurements, capturing fine details in the underwater topography.

4. Accuracy: ± 0.01 m + 0.1% x Water Depth: Specifies how closely the measured depth aligns with the actual depth. The stated accuracy is within ± 0.01 meters, with an additional 0.1% of the water depth, ensuring reliable and precise depth measurements.

5. Frequency: 200 KHz: Indicates the frequency of the sonar waves emitted by the echo sounder. A higher frequency, such as 200 KHz, is suitable for detailed and high-resolution underwater mapping.

6. Sound Velocity Adjustment Range: 1300 m/s to 1700 m/s: Allows adjustment of the speed at which sound waves travel through water. This adjustment accounts for variations in water conditions, ensuring accurate depth measurements under different circumstances.

7. Beam Angle: 6.5 + 1 degree: Describes the width of the sonar beam emitted by the echo sounder. A beam angle of 6.5 degrees with a tolerance of ±1 degree defines the coverage area beneath the vessel, impacting the survey's efficiency and coverage.

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