What is defined as the smallest signal that is detectable by a receiver system that can be processed and presented on an indicator?

The term that describes the smallest signal detectable by a receiver system that can be processed and presented on an indicator is known as the "usable echo." This concept is critical in radar and sonar applications, where being able to distinguish between useful signals and background noise is essential for effective target detection.

A usable echo represents the minimum level of signal strength that can be actively processed and interpreted as a valid piece of information by the system. For radar systems, this could involve distinguishing between the reflected energy from a target and any ambient noise. When a usable echo is reached, it ensures that the detected signal can be reliably interpreted, allowing operators to make informed decisions based on that data. Consequently, the focus on defining this parameter is key for optimizing system performance in various tactical and operational scenarios.

Understanding the concept of usable echoes also enhances the capability of technicians and operators to adjust system parameters for improved detection capabilities, thereby improving the overall effectiveness of the fire control system.