Drone bathymetry in the Mediterranean and the Dead Sea

The challenge

Bathymetric surveys at sea are usually run from a crewed boat. SPH Engineering's drone echo sounder system was first aimed at small-scale surveys of inland water bodies. ERELIS set out to test it in coastal water, including the very dense water of the Dead Sea.

The solution

A standard commercial DJI drone carried the SkyHub onboard computer, a terrain-following system with a radar altimeter and an EchoLogger ECT400 single-beam echo sounder, all supplied by SPH Engineering. The data was processed in Eye4Software Hydromagic.

How the data was checked

Authorised local surveyors validated the results. They were also compared with reports from earlier surveys of the same areas by the Michmoret Campus, Faculty of Marine Sciences. That reference data had been collected from a crewed boat with multibeam and single-beam echo sounders.

The results

• The drone-based results matched the traditional boat-based results well.
• Some survey areas were 400–500 m from the take-off and landing point. ERELIS CEO Roman Kirsanov said he was struck by how manoeuvrable the system was and how easy the surveys were to run.
• SPH Engineering CTO Alexey Dobrovolskiy said the results mean SPH can now also recommend the system for small-scale coastal surveys, and for almost any liquid. The Dead Sea's water density is 1.24 kg/L.

SPH Engineering notes that the method has also been used in other countries, including Denmark and the UAE, for mapping, measurement, inspection and environmental monitoring.

Where this applies in India

The same setup suits small-scale surveys in coastal and dense water:

• near-shore surveys along beaches and around small harbours and jetties;
• backwaters, estuaries and coastal lagoons;
• brine ponds and salt works, where the liquid is denser than fresh water;
• shoreline and seabed monitoring for coastal protection studies.

SPH Engineering's bathymetry training is also available through HobiTech.

The equipment, available from HobiTech

Echo sounder	EchoLogger ECT400 was used in this project. We sell the EchoLogger ECT 400S.
Onboard computer	SkyHub by SPH Engineering with the SkyHub echo sounder software
Terrain following	Radar altimeter with SkyHub. See the True Terrain Following software package.
Drone	A standard commercial DJI drone was used. Ask us for current compatible drones.
Processing	Eye4Software Hydromagic

Case study by SPH Engineering, published May 2021. This page summarises it in our own words; the surveys were carried out by ERELIS, not by HobiTech. Read the original case study on SPH Engineering ↗