ROVs or underwater drones combined with sonar navigation systems are proving to be the ideal duo for search and rescue operations in murky water.
Turbid water is inherently dangerous to navigate in. Visibility below the surface can vary from a few meters to a few centimeters. In some cases, the water is even so dark and dense that you cannot see your hand millimeters from your face. In conditions where visibility is dangerously low, search and rescue operations are extremely difficult to carry out. For example, it is impossible to determine the parameters of the diving area. Consequently, divers are faced with unknown and potentially unsafe conditions, which in turn increases the concern for their safety.
Searching in murky water – Seeing through a murky environment
Although the human eye cannot see through water, technology offers the ability to navigate and identify targets in murky water. Each Deep Trekker underwater drone comes with a built-in HD camera. Those who want a sharper image can upgrade these underwater robots with a 4K camera, which offers even more image and contrast. But even with the most advanced cameras, it has always been difficult to film in murky water. That is now in the past thanks to technological advances in ROV navigation systems, such as sonar.
Sonar navigation systems have already proved to be of direct use to search and rescue teams. They are now quietly seeing the benefits of this advanced technology. Indeed, sonar has brought greater success in finding lost or discarded targets as well as carrying out safe and effective salvage missions.
For example, side-scan sonar systems are towed behind boats to search a large area of water. Initially, the entire search area is divided into a grid. The side scan is then towed through the entire grid. Each area is checked twice to ensure that the area is fully explored.
Identification of the target
Once the side scan has searched the area, search and rescue teams can mark areas of interest. These are areas where their target may be located. Traditionally, divers are used at this point, who must navigate through the murky water in the hope of finding their target. With zero visibility, these divers must rely on their sense of touch to move around and locate their target.
This process is repeated until the mission is complete. However, divers have a limited time they can spend underwater. Otherwise, it becomes even more dangerous for them. Moreover, each operation has a maximum depth they can dive to. So, depending on the water temperature and other external factors, divers may be limited to just an hour underwater. Are they underwater for longer? Then they run the risk of hypothermia.
Alternative to search in murky water
Remote-controlled vehicles are increasingly used in search and rescue operations. Not to replace divers. But to cooperate with them. As with traditional methods, the ROV can be deployed quickly to identify the target. Provided the side scan has completed its sweep and identified areas of interest.
In a search in murky water, the standard camera on the underwater drone will work much like the human eye. In other words, it will be difficult to navigate through the water. And this is where sonar systems come in handy. The ROV pilot navigates from the surface through the poorly visible water. He does this solely with the help of the sonar’s heads-up display (HUD). You can compare it to a pilot relying on his aircraft’s instruments when flying through fog.
Identifying the target
Once the underwater drone has successfully identified the target, it is up to the divers. They follow the ROV’s cable directly to the target and prepare it for collection. If the location is a crime scene, the ROV can record and document the area for the investigation. Most importantly, the diver’s safety can be closely monitored from the surface while the target is being retrieved.
Search and rescue vehicles
The Deep Trekker DTG3 and REVOLUTION are remotely operated vehicles that are fully portably. This is made possible thanks to the internal rechargeable batteries, allowing the entire unit to fit in a carrying case. The ROV can operate for up to 8 hours on a full charge. This allows search teams to do more than a normal diver. Thanks to a recharge of just 90 minutes, the unit is ready for another day.
This portability of the ROV is extremely important during a search and rescue operation. Since bodies of water are in the most remote locations, teams may need to get there via air of on foot. This is where the DTG2 is perfectly deployable: it comes in a carrying case, so it can be transported to and deployed in these isolated areas.
Moreover, the underwater drone can be equipped with a grappling arm to pick up a submerged target and bring it to the surface.
Contact us if you want to know more about underwater drones for search and rescue operations. We will find a solution tailored to your needs.
