How the Aviation Radar System Works

The aircraft radar system has become a critical asset to countless operations ranging from air traffic control to general navigation. Through their implementation and use, radars have increased the safety and operational efficiency of the entire industry. While some may be familiar with the basics of radar technology, others may not be aware of how they are used for aviation and what benefits they can provide.

The term “RADAR” is an acronym standing for Radio Detection And Ranging, and the technology was first invented during World War II for military use, though later was introduced to more industries and applications over time. For the detection of objects, a radar system will utilize electromagnetic waves that are transmitted as radio waves. As electromagnetic energy travels at a constant speed reaching upwards of 300,000 kilometers per second, distance can be determined by measuring the amount of time between the transmission of the pulse and when the reflection is received.

Depending on the conditions present, a radar system may be used to retrieve the direction, altitude, distance, course, and the speed of objects it is measuring. At the frequencies that electromagnetic energy is transmitted by the radar, waves are unaffected by darkness and can penetrate both fog and clouds. As such, radar equipment is indispensable for identifying unseen objects in a variety of weather conditions for safety.

While radar systems may vary in their design and functionality, the basic components that make up most devices are the transmitter, antenna, receiver, duplexer, power supply, and indicator. The transmitter is what is used to generate the radio wave, and it modulates the wave to form a pulse train. The antenna then serves as the medium for the radio wave to move from the device and into the air. As the signal is sent out and bounced back, the receiver ensures that the signal is both amplified and demodulated before relaying a video signal to the indicator so that a visual display is provided to convey information in a more easily digestible way. The duplexer of radar systems is a type of switch that functions as an alternate connection point for the transmitter and receiver, and it may be used to guard the receiver from the transmitter’s high power output. Lastly, the power source is important for the overall functionality of the system by providing sufficient electrical power.

Primary and secondary radar systems are the two main types available, and they both rely on somewhat similar operations to detect and track objects. Utilizing reflections or echos, the primary radar measures the duration of the signal from transmission to being received again. Utilizing RF pulses for finding the range and bearing of an object, the primary radar is often used in civil aircraft as a weather radar, radio altimeter, and for doppler navigation.

The secondary radar differs in its operations, ignoring the pulses and echoes that reflect back completely. Instead, such radars send signals outwards until it reaches the transponder of an object and then relies on the transponder to relay data back as a reply. As the signal does not need to be reflected, secondary radars can send out signals much further, though require a transponder to respond such as on an aircraft or ground station. Generally, such radar types are most often used as a Secondary Surveillance Radar or as Distance Measurement Equipment.

1. jacob luiz
2. Posted on March 25, 2021
aviation