Echo Sounder
Bathymetry of waterways, lagoons, lakes, ponds, harbors
Dredging planning and monitoring
Construction planning
TSF (Tailing Storage Facilities) monitoring
Sediments monitoring

How it works

An echo sounder is a device to measure the depth of water (or any liquid). An echo sounder sends out sound waves and measures how long it takes for the echo of the sound to come back. The speed of sound in the water is known so that the depth can be calculated. Echo sounders are crucial tools for environmental monitoring and mapping underwater terrain.

The results of depth measurements using an echo sounder or bathymetric survey can be presented in several forms.
Most popular are:

Colored depth or elevation maps and contour maps with isolines of equal depth

Cross-section profiles

CSV files with coordinates and depth or bottom elevation

Data in the form of point cloud

SPH Engineering offers three standard configurations of the SBES systems, with single and dual-frequency echo sounders

There are multiple different types of devices utilizing echo sounding principle. Single-beam echo sounders (SBES), which may be single-frequency and dual-frequency; multi-beam echo sounders (MBES), scanning sonars, and side-scanning sonars. All these, except SBES, are usually bulky and heavy and not suitable for UAV deployment, at least without a kind of towed buoy. Additionally, the Echo Sounder sensor often incorporates advanced features such as temperature sensor and tilt sensor.

All sensors are manufactured by Korean company EofE Ultrasonics Ltd., specializing in survey-grade sonar products.

ECT 400S single-frequency echo sounder with an acoustic frequency of 450 kHz

It measures the distance till the first “obstacle” in the water - sediments, seaweeds, and even fish. Therefore, if the bottom of the survey area is covered with seaweed, this basic configuration may not work for such a case.

The measured depth will fluctuate erratically depending on what echo sounder received reflected sound - bottom or vegetation. That means that to get “clean” readings from EchoLogger ECT 400S the bottom should be without seaweeds, ensuring a precise depth measurement.

The benefit of EchoLogger ECT 400S is that it has a very short dead zone of 15cm - a minimum distance it can measure. That makes the system with ECT 400S suitable for very shallow surveys, starting from approximately 30cm deep.

Drone based ECT 400S single-frequency echo sounder with an acoustic frequency of 450 kHz

ECT D24S dual-frequency echo sounder with an acoustic frequency of 450 and 200 kHz

Technically, a dual-frequency echo sounder is two devices with different acoustic frequencies, combined in one compact housing.

The higher frequency is 450 kHz, and it will give measurements till the first surface or obstacle. The lower frequency is 200 kHz, and sound with that frequency will pass through seaweeds/vegetation on the bottom, and the device will report clean readings of the bottom.

Note: the dead zone for 200 kHz is 0.5m, limiting the minimum practical survey depth for 
that device by approx 0.8m.

EchoLogger ECT D24S is a dual-frequency sounder with tilt and temperature sensor.

Schematics illustrates that the sound waves of the ECT D24S dual-frequency echo sounder with an acoustic frequency of 450 and 200 kHz is a two devices with different acoustic frequencies, combined in one compact housing. The higher frequency is 450 kHz, and it will give measurements till the first surface or obstacle. The lower frequency is 200 kHz, and sound with that frequency will pass through seaweeds/vegetation on the bottom, and the device will report clean readings of the bottom.
Image demonstrating ECT D24S dual-frequency echo sounder data with Eye4Software Hydromagic software

Fig.1 -The graph demonstrates the technology: the red line reflects 450 kHz sound, fluctuating between seaweed and the bottom, while the green line (200 kHz) provides steady depth measurements

ECT D052S dual-frequency echo sounder with an acoustic frequency of 200 and 50 kHz

200 kHz sound impulses will reflect from the top surface of the bottom, but 50 kHz sound can penetrate through organic or light sediments, measuring the depth till the hard bottom.

That creates the possibility of mapping the depth and measuring the thickness and amount of sediments in the water body.

Note: the dead zone for 50 kHz is 1m, and the minimum practical survey depth will be around 1.2m.

EchoLogger ECT D052S is a dual-frequency echo sounder with tilt and temperature sensor.

Schematics illustrates that the sound waves of the ECT D052S dual-frequency echo sounder with an acoustic frequency of 200 and 50 kHz is a two devices with different acoustic frequencies, combined in one compact housing. 200 kHz sound impulses will reflect from the top surface of the bottom, but 50 kHz sound can penetrate through organic or light sediments, measuring the depth till the hard bottom. That creates the possibility of mapping the depth and measuring the thickness and amount of sediments in the water body.
Measurement range
0.15 .. 100 m
0.50 ... 200m (200 kHz)
0.15 … 100m (450 kHz)
1.00 .. 200 m (50 kHz)
0.50 .. 200 m (200 kHz)
Sediment measurements
Yes
Integrated tilt sensor
Yes
Yes
Yes
Integrated temperature sensor
Yes
Yes
Yes
Weight (full assembly in air)
2.4 kg
2.4 kg
2.7 kg

Tell us more about the place you want to survey and its conditions

And we will help you choose the best option

Benefits of echosounder with UAV

The echo sounder is the standard measurement tool for bathymetry (depth measurement). Usually, the survey process involves using a ship, boat, or unmanned surface vehicle (USV) as a platform for the sensor.

Sometimes, the use of a boat can be complicated, especially in small or hard-to-reach rivers and lakes. The use of USVs is not feasible in every situation because of underwater features. Firstly, it is necessary to have a good point of entry to the water for deployment and recovery. Secondly, using USVs in shallow lakes with lots of seaweed may be impossible. Last but not least, in many cases, a USV should be big enough to resist waves if water analysis is conducted in water in oceans, and a large vehicle may be necessary to transport it.

The UAV is a good alternative for carrying the echo sounder

A drone is compact and easy to transport and deploy. Drones also have a high precision of following planned survey lines and can be used anywhere where there is at least a small area for take-off and landing near the surveyed water surface.

Hard-to-reach locations

The UAV system is ideal for hard-to-reach locations (steep coasts, mining pits, shallow waters, terrain obstacles), as well as waters of ponds, lakes, and canals. There is no need for an entry point to the water for deployment and recovery. There are applications where the surveyed area was a few hundred meters from the take-off location.

2 times more cost-efficient

For small water bodies or survey areas, the mobilization cost for the boat or USV with bathymetric equipment may exceed the survey's price. Highly portable UAV system saves time for mobilization and deployment and may be up to 2 times more cost-efficient than a standard approach using a ship, a boat, or a USV.

Works in a hazardous environment

The system works in a hazardous environment, which humans cannot approach freely. A drone operates without water contact. Therefore, lakes and rivers with strong currents, as well as contaminated waters, become measurable.

Precise positioning

The drone's precise positioning while following the survey routes and ability to fly at a constant speed and specified low altitudes result in high-accuracy measurements.

Typical applications

Physically, disregarding of applications, echo sounders will measure the same. However, applications may dictate survey planning, data processing, and final reporting differences. Below is the list of typical applications for the drone-borne echo sounder systems:

Drone-borne echo sounder with SkyHub for dredging planning and monitoring; technology by SPH Engineering
Photo © AltoMaxx Technologies Inc.

Dredging planning/monitoring,
contractor quality control

Drone-borne echo sounder with SkyHub for Construction planning: piers, bridges etc; technology by SPH Engineering
Photo © Aeromedia U.A.V., S.L.

Construction planning
(piers, bridges, etc.)

Drone-borne echo sounder with SkyHub for bathymetry of surf zones; technology by SPH Engineering
Photo © ERELIS

Bathymetry in surf zones

Drone-borne echo sounder with SkyHub for aggressive liquid storage facility bathymetry; technology by SPH Engineering
Photo © Mohawk College

Sediments build-up monitoring

Drone-borne echo sounder with SkyHub for TSF & open pit lake monitoring, volume of water and capacity; technology by SPH Engineering
Photo © Innotech-Drone SAS

TSF & open pit lakes monitoring (volume of water and capacity)

Photo © HPC Industrial powered by Clean Harbors

Aggressive liquids storage facilities bathymetry

Photo © Aerospectrum Inc.

Environmental: bathymetry, sediments, seaweeds

Rivers cross-section profiling for maximum discharge calculation with drone based echo sounder technology by SPH Engineering
Photo © UAWOS (Unmanned Airborne Water Observing System)

Rivers cross-section profiling for maximum discharge calculation

Tell us about your case

And we will help you select the appropriate echo sounder for your application

System components

The echo sounder system for UAV consists of multiple components. For your convenience, all necessary components, software, and services are combined into echo sounder bundles.

Compatible drones: DJI M300/M350/M600, Inspired Flight IF1200A, Harris Aerial H6, and Wispr Ranger Pro and similar UAV

Echo Sounder
In heavy housing with suspension system
+
SkyHub onboard computer
Acts as datalogger for echosounder data and implements True Terrain Following mode for DJI drones
+
Laser or Radar altimeter
Laser or Radar altimeter to fly automatically in terrain-following mode for precise altitude
+
UgCS flight planning software
Drone flight planning software for mission planning and flight control, essential for accurate echo sounder data collection.
+
Eye4software Hydromagic Survey
Bathymetric data processing software

Accuracy of the system

Fig.2 - Image representing the correlation between drone-mounted system with echo sounder and measurement pole with Trimble RTK GNSS receiver (in red circles)

In bathymetry, traditionally dominated by boats, there is a growing presence of UAV-based solutions incorporating echo sounders for bathymetric data collection. That raises the normal questions about the accuracy of the system.

As the UAV-borne system uses survey-grade echo sounders and hi-end RTK GNSS receivers of the modern drones for the positioning, the accuracy of the data collected using drone-mounted systems is the same as for manned and unmanned boats.

Our customers compared data collected using drones with more traditional methods. The image (see Fig.2) is a track of the data from the drone collected using a measurement pole with Trimble RTK GNSS receiver (in red circles), data courtesy of Geopartner Landinspektorer A/S. That method of measurement is considered to be the most precise. It is visible that the difference is negligible.

Case Studies
More Case Studies
Data Sets

The echo sounder system records data in three standard formats:

  • NMEA0183 as the most common and convenient for the processing format
  • SEG-Y files with full echosounder data
  • CSV files

Discover the data sets for all three standard types of drone based echosounders by SPH Engineering.