Radar or Radio Detection and Ranging is a system of detecting objects using radio waves. Radar employs radio waves to determine the range, angle and velocity of objects such as aircraft, missiles, ships, motor vehicles etc. A radar system consist of a transmitter producing electromagnetic waves in radio or microwave domain, a transmitting and receiving antenna, and a receiver and processor to determine the properties of the objects. Radio waves from the transmitter reflect off the object and return to the transmitter giving information about the object. Radar was first developed for military use before World War Two but is now used in many areas such as air traffic control, anti missile systems ocean surveillance, air defense systems, marine communication and location systems, weather forecast etc.
A radar consist of the following;
A transmitter that generates the radio signal with an oscillator such as klystron or a magnetron and controls it’s duration by using a modulator.
A waveguide that links the transmitter and antenna.
A duplexer that servers as a switch between the transmitter and antenna or the receiver for the signal when the antenna is used in both situations.
A reciever which received the signals.
A display processor to produce signals for human readable output devices.
An electronic section that controls all the devices and the antenna to provide the radar scan ordered by the software.
A link to end user devices and display.
Radar is extensively used in the aviation industry for safe navigation of aircraft during takeoff and landing. Large radar antenna are installed at airport grounds to detect aircraft in the air and keep track of their movements. Aircraft are equipped with radar devices that warn of other aircraft and obstacles on their path. They also display weather information and give accurate altitude readings. Aircraft can land in fog at airports equipped with radar assisted ground controlled approach systems. Military combat aircraft are also equipped with air to air targeting radars to detect and target enemy aircraft. High grade military radar installed on larger specialized military aircraft can be used to observe air traffic over long distances and relay the information to accompanying fighter aircraft or command center for targeting.
Radars used on ships are used to measure the bearing and distance of ships to prevent collision with other ships, to navigate and to fix their position at sea when within range of shore or other installations such as bouts and light houses. In Port or harbour, radar systems are used to monitor and regulate ship movements in busy waters.
Radar is also used by meteorologists to monitor precipitation and wind. It is used to forecast weather conditions such as thunderstorms, hurricanes, cyclones, tornardoes. Geologists use specialized ground penetrating radar to map the composition of the Earth’s crust. Smaller radars are used to monitor human movements such as breathing pattern detection for sleep monitoring and hand and finger gesture detection for computer interaction. Others include automatic door opening, light activation and intruder sensing.