*4.2. Research Equipment and Configuration*

In this study, the autonomous anti-collision system for the HydroDron was an automotive radar sensor, a type 42 UMRR automotive 3DHD radar with a 24 GHz microwave sensor. The radar sensor was mounted on the unmanned surface vehicle HydroDron.

The HydroDron is an autonomous catamaran, 4 m long and 2 m wide, which is being developed as a prototype intelligent autonomous multipurpose surface vehicle dedicated to hydrographic measurements. The HydroDron can perform tasks in water areas that are inaccessible or difficult to access by larger vessels. The popularity of this type of vehicle is continually increasing because of its potential to install more sensors and perform surveys in the absence of an onboard operator. The weight and maneuverability of the vehicle have been reduced to meet the objectives of its deployment. The platform has a wide range of measuring equipment—an integrated bathymetric and sonar system, an external inertial navigation system, a sound velocity profiler and sound velocity sensor, a GPS receiver, a high-frequency single-beam echosounder, a single-beam dual-frequency echosounder, two cameras, LiDAR, and a UMRR 0C Type 42 radar.

One individual sensor (3D/UHD 24 GHz radar) is employed for traffic management, simultaneously measuring many parameters, such as angle, radial velocity, range, reflection coefficient, and the entire series of motionless and motion reflector parameters. It is possible to detect many reflectors that are simultaneously in the field of view; as many as 256 targets can be detected at once. This number can be halved depending on the selected communication interface. Sorting of these reflectors is based on the range; if more than 128 targets are detected, then short-range targets are reported first. The radar is suitable for determining the speed and lighting in red light, and the sensor can be used in approaching or in receding traffic mode [19]. Figure 7 shows the radar mounted on the HydroDron platform with sensors, including the rotating and stationary camera, mounted to increase visual data collection.

**Figure 7.** Experimental system (**a**) ASV HydroDron and (**b**) radar 3D/UHD 24 GHz sensor mounted on the HydroDron platform.
