Sonars are useful pieces of equipment in situations where visibility is low. Sonars can help get ranges to surfaces or acoustically image targets to better understand their shape.
Echosounders and Altimeters
A useful type of sonar is an echosounder, also known as an altimeter when installed on an underwater vehicle. An altimeter is a single-beam sonar which gets a range measurement from the bottom of the ROV to the seabed. This is useful in low visibility situations where the distance to the bottom is unknown.
In addition to getting a distance reading, echosounders can provide the full echo response (echo strength versus time) which can be plotted like the display of a fishfinder sonar. This is useful for locating targets or obstructions beneath the vehicle.
- Blue Robotics Ping Sonar Altimeter and Echosounder (USB connection to Companion Computer)
Scanning Imaging Sonars
Mechanically scanning sonars are useful tools for navigation, and acoustically imaging targets in a top-down 2-dimensional representation. If you are new to scanning sonars, Blue Robotics has written an introductory guide which illustrates the key concepts and can help with image recognition: Understanding and Using Scanning Sonars.
Supported Scanning Sonars
Only the Blue Robotics Ping360 Scanning Sonar is fully integrated with the ArduSub system and has advanced features such as heading rotation and a direct connection to the Companion Computer.
The following scanning sonars have been installed on ArduSub vehicles:
- Tritech Micron Sonar (RS485 connection through tether)
- Imagenex 852 Ultra-Miniature Imaging (RS485 connection through tether)
Multibeam imaging sonars are similar to mechanically scanning sonars in that they acoustically image targets in a top-down 2-dimensional representation. However, with multiple sonar beams the refresh rate is much righer and presenting a real-time image of what is in front of the vehicle.
The following multibeam sonars have been installed on ArduSub vehicles:
- Blueprint Subsea Oculus Series Multibeam Sonars (Ethernet)
- Tritech International Gemini 720im Multibeam Sonar (Ethernet or RS485 connection through tether)
- Tritech International Gemini 720ik Multibeam Sonar (Ethernet)
Profiling sonars are 1-dimensional echosounders with a rotating head that are able to get accurate acoustic range data to create a "profile" of the surrounding environment. These types of sonars are useful for inspecting material buildup in pipes.
The following profiling sonars have been installed on ArduSub vehicles: