What device is used to record SONAR data?

The device referred to in the correct answer, the Sonar Data Recorder (SDR), is specifically designed for the purpose of collecting and storing sonar data that is generated from underwater sound waves used for navigation, mapping, and detecting objects. The SDR captures these data inputs effectively, allowing operators to analyze them later for various applications, such as search and rescue missions or underwater exploration.

While there are other devices mentioned in the options, they either serve broader purposes or are not specialized for sonar data recording. For instance, a sonar recorder may not necessarily refer to a specific type of data recorder for sonar applications. A data acquisition system can record various types of sensor data but is not exclusively tailored for sonar data. A sonar feedback unit typically provides real-time information to the operator rather than storing recorded data for later analysis. The SDR's specialized function is what distinguishes it as the correct choice in this context.