Scientists can detect and measure motion using radar technology. A radar uses electromagnetic energy to send out radio waves. The echoes are then received by the device. The signals can be used for measuring the atmospheric properties and to track objects. Radar technology was first used in the early 20th-century.
An antenna and receiver are the components of a radar system. They receive and amplify the reflected signals from objects. Scientists can use this technology for measuring the speed and direction of an airplane's movement, as well as the size of a fire. Radar is used for detecting a wide range of objects including aircraft, ships and spacecraft. It is also used to monitor the weather.
The first radar system was created by Christian Hulsmeyer in 1904. Christian Hulsmeyer in 1904 created the first radar system. He discovered that electric waves from metal surfaces could be used for detection of metal objects. He realized that radio signals could also be bounced off metal objects. He named the unit of frequency "Hertz" after himself. He collaborated later with the U.S. Naval Research Laboratory to develop high-frequency radio communications. He concluded that radio waves can be used in order to detect ships.
The most popular radar type is called "continuous waves" and uses two antennas. It is used in search and rescue operations, air traffic control and traffic monitoring.
Other types of radar are pulse radars that work on pulsed signals. These signals have a brief delay but can travel long distances. The distance of an object can be measured by the time it takes for a pulse back to the radar. This signal can also be called a pulsetrain.
Superheterodyne is another form of radar, and it uses only one frequency signal. This type of radar is typically large and heavy. This radar is susceptible to cooling problems. However, the technology is well understood so it does not affect the radar's performance.
Multi-channel sensors can also be used to monitor the movement of the target from multiple angles. These sensors can combine historic information with instantaneous data to solve complex movements. This is evident in the radar, which can measure the speed and direction of a moving storm.
A pulse train cannot measure the speed of moving objects like the weather radar. However, a pulse train can be used to determine the distance between two objects. This type radar is also called Doppler radar.
In a Doppler radar, the frequency of the reflected signal changes as the object moves. This makes the Doppler radar useful for ground-based radars. However, unlike weather radar, Doppler radar can not be used to detect stationary objects or moving storms.
Another type of radar, AESA, is active electronically scanned array. These radar systems employ individual transmitters and receive module, which are controlled via computers.