1. Ground-Based Radar: Radar systems are widely used to track and measure the speed of aircraft. Radar stations on the ground emit radio waves that reflect off the aircraft's surface and return to the receiver. By calculating the time it takes for the signal to travel to and from the aircraft, the radar system can determine the aircraft's velocity relative to the ground.
2. Inertial Navigation System (INS): INS is an onboard system that uses motion sensors, such as accelerometers and gyroscopes, to continuously track the aircraft's position, orientation, and velocity. INS provides accurate measurements of the aircraft's speed relative to its starting point.
3. Air Data Sensors: Aircraft are equipped with sensors known as air data probes or pitot tubes. These sensors measure the dynamic pressure, or ram air pressure, caused by the aircraft's forward motion. By combining this measurement with other data, such as air temperature and altitude, air data systems can calculate the aircraft's true airspeed.
4. Doppler Effect: The Doppler effect refers to the change in frequency of a wave as its source or observer moves relative to each other. In the context of aircraft speed measurement, Doppler radar systems utilize this principle to determine the aircraft's velocity. By analyzing the shift in frequency of radar signals reflected off the aircraft, Doppler systems can accurately calculate the aircraft's speed.
5. GPS (Global Positioning System): GPS utilizes a network of satellites to provide accurate positioning and navigation data. By receiving and processing signals from multiple GPS satellites, aircraft can determine their position, velocity, and ground speed with high precision.
These techniques, either used individually or in combination, allow for precise measurement of jet speeds. The choice of method may vary depending on factors such as the specific aircraft type, flight conditions, and required accuracy of the speed measurement.
