What is the primary radar?
The primary radar system transmits a high -performance radio frequency from the rotating antenna and uses any reflected signals to determine the distance and speed of objects in the air or on water. The radio signal shows the distance to the object since the return path to the object is needed. For a radar used to control the aircraft, you can also return the returning signal to determine the approximate altitude of the aircraft or height above the ground. The antenna is a curved metal bowl or structure that focuses the radio beam and transmits it in a specific direction.
The radar is an abbreviation or shortened version of the term "radio distance and range". Soon the radar developed for the first time to detect aircraft in the 30s of the 20th century, at that time it had a limited range due to the performance limits for antennas. Although the power supply and software of the antenna improved, at the beginning of the 21st century there is a practical limit of primary air traffic radar about 60 miles (100 kilometers).
Using primary radar requires a lot of signal output, becausee objects further from the antenna will reflect or send back a weak signal. For longer distances from the antenna, the radar becomes unreliable as a way to determine the position of the aircraft only by reflected signals. The increasing amount of air traffic in the 20th century created the need for other aircraft location systems.
In the 1960s, the aircraft began to use transponders to help control air traffic. The transponder is both a receiver and a transmitter that receives a radar signal from the primary radar and sends a signal that contains an aircraft identification, altitude and speed. This so -called secondary radar improves the accuracy of the aircraft position, because the transponder is driven by aircraft and transmits a stronger signal than the primary radar signal.
Improved transponders starting at the end of the 20th century also provided additional aircraft. Pilots could choose the settings they say on the ground controlAir unit of air traffic, if the aircraft is kidnapped or under the control of other persons or if there is an emergency deck. These active signals were sent to a secondary radar receiver located on the same antenna as the primary radar and can be displayed on the operation control screens.
water boats can also be detected using radar systems with certain limitations. High waves can mask or hide radar returns of smaller ships and curvature or shape of the ground prevents the boats from seeing the horizon. Large military ships can use the shapes or coatings of radar configuration that absorb the radar to appear so many smaller ships on the radar screens.
Radar can also be used to detect weather. Molecules of water in the clouds may reflect some frequencies of radar signals that will show clouds containing rain. Early systems could only see moving drops, but LAT20 systems. The century can detect moisture even without rain.
doppler radar can detectOut the speed and direction of water droplets moving through the air. The reflected signal is analyzed by software that shows whether the signal moves towards or from the antenna. It can show a rotation indicating a possible tornado, even at night or when hidden with heavy rain.