What does a Plan Position Indicator (PPI) display?

A Plan Position Indicator (PPI) is a type of radar display that presents data in a top-down view at a constant elevation angle. It uses spherical coordinates to depict the location and intensity of radar returns, typically visualized as a circular plan view. This allows meteorologists and meteorological technicians to assess the spatial distribution of precipitation, storm activities, and other atmospheric phenomena over a specified area from a single radar location.

The PPI display is particularly useful for tracking the movement and development of weather systems, providing information in a format that is intuitive for understanding the horizontal extent of radar echoes. Since the PPI captures data at a set elevation angle, it enables users to monitor phenomena like thunderstorms, rain bands, and other meteorological events as they evolve over time.

This characteristic distinguishes the PPI from other radar displays that might require different assessments, such as vertical profiles of the atmosphere or horizontal cross-sections at multiple elevations.