The material for this page was generated from two locations, first at the headquarters of the local rescue service (DLRG) in Germany, on a lake near Munich, and at the water rescue unit's office on Lake Achensee in Austria.
The small DLRG's ROV (FiFish V6) was meant to practice the cooperation between divers and the ROV, while the Munich police wanted to test how UWIS is suitable for guiding their existing, older ROV. The same situation was in Austria. The tracking systems that came with the ROVs had never worked as expected and were therefore out of order. It made it virtually impossible to control ROVs based on video alone. In addition, the compasses of the devices were not reliable.
Below are images of how the UWIS Diver Units were attached to the ROVs. The best place for it is on the most visible place in relation to the UWIS buoys and so that it has no solid surface very close (approx. 30 cm) in the "field of view" of the unit.
The UWIS buoys are spread at a distance of about 30-70m from each other, in as isosceles triangle as possible so that the Master buoy is closest to the tracking computer. A anchor weight of about 2-3kg is enough. We recommend using a reel with a rope of approx. 2-3mm thickness and a quick release for the buoy. Then installing and removing buoys doesn’t take much time. Only if operated in a deep and high current location may it be necessary to increase buoyancy alongside the UWIS buoys to prevent them from sinking underwater.
The image shows a view of the UWIS Tracker program in a situation where two groups of divers return from their longer route and the ROV finds them.
With tracking settings, UWIS is able to provide location information every two seconds (2s / unit) as well as depth. The program can also be used to transfer the location data of one UWIS Diver Unit to another computer (NMEA, GGA) using the serial port. If this computer has, for example, ROV control software that supports the import of external location information, such as an external GPS, then the ROV will be displayed there as well.
Real-time monitoring can also be implemented with DeepView software, for which the ability to listen to UWIS buoy messages wirelessly has been developed in collaboration.
The ROV operator can use either a freshly scanned or previously recorded side scan image at the bottom to guide the ROV to the targets. There was no images available in this time, so we uploaded a Google satellite image to the background. Route line drawing and recording was started only at the very end of the dive.
Below is a image of the cab and ROV in action. By installing an external wifi antenna for UWIS, it is possible to operate inside the boat and the distance to UWIS buoys can be clearly longer than using the computer's own wifi alone.
Attached is a route from an ROV dive imported into Google Earth. With a little practice and a working compass, the search can be done very systematically unlike this time. The UWIS Tracker program collects the dive routes and, as here, the routes can also be read from the UWIS buoy afterwards, in which case all the information that has been accumulated during the dive is available.
Advantages of the UWIS System over other tracking systems on the market:
- Wireless system
- Allows underwater navigation at the same time
- Tolerates difficult acustic conditions and thus works e.g. in quarries, ports and waters with thermoclines.