The most basic type of scanning indicator is the:

The most basic type of scanning indicator is the plan-position indicator (PPI). A PPI is commonly used in radar systems to display the position and movement of objects in a two-dimensional format. It presents a top-down view of the surrounding environment, enabling operators to easily interpret the information displayed concerning the position, range, and bearing of targets.

The PPI works by plotting the location of detected objects on a screen in real-time, allowing for effective situational awareness. This type of indicator is fundamental because it provides a simple and intuitive way to visualize data, particularly in contexts like air traffic control, maritime navigation, or military applications, where understanding spatial relationships is crucial.

Other types of scanning indicators might include those that offer three-dimensional displays or additional features like elevation angles but would not be considered as basic or foundational as the PPI. The straightforward nature and essential functionality of the PPI make it a fundamental tool in numerous radar and scanning applications.