Plan Position Indicator in Radar – Block Diagram | New Topic

In this note, we are going to know about the Plan Position Indicator in Radar System and its block diagram. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

What is Plan Position Indicator in Radar?

A Plan Position Indicator (PPI) is a type of radar display that shows detected targets in two dimensions, similar to a map. It represents range and azimuth (angle) data, indicating the position of objects relative to the radar’s antenna. The display is normally round, with the radar in the center.

As the radar antenna rotates 360 degrees, the PPI displays echoes from nearby targets on a flat screen in real time. It is commonly used for air traffic control, weather monitoring, sea navigation, and military surveillance.

Block Diagram of Plan Position Indicator with Explanation

Here is the plan position indicator block diagram, along with an explanation of each block.

• Transmitter: The transmitter produces short-duration, high-power RF pulses. These pulses are transmitted through the antenna to detect things. The distance and clarity with which the radar can detect targets are determined by its power and pulse width.
• Duplexer: The duplexer functions as a switch, alternating between transmitting and receiving modes. It shields the receiver from high-power transmit pulses and enables the simultaneous use of a single antenna for transmission and reception.
• Antenna: The antenna sends RF pulses and receives echoes from objects. It rotates 360 degrees in a horizontal plane to cover the surrounding region, allowing the radar to scan all directions around the site.
• Receiver: The receiver amplifies and processes weak return signals (echoes) received from the target. It filters noise, detects the signal, and converts it into a form suitable for further signal processing and display on the screen.
• Target Echoes: These are reflected signals that bounce back from objects like planes, ships, and terrain. The strength and delay of the echoes aid in determining the location, size, and movement of the detected targets.
• Signal Processor: The processor cleans up the received data, eliminates noise, calculates range and angle, and prepares the signals for display. It converts analog radar signals to digital format, resulting in clear and accurate visual representation on the PPI.
• Display: The Plan Position Indicator screen provides a top-down picture of targets surrounding the radar. Targets appear as dots or blips on a circular screen, with range increasing outward and angle depending on antenna orientation.