The history of radar began with the experiments of Heinrich Hertz in the late 19th century, which showed that radio waves were reflected by metallic objects. Radar development was essentially motivated by military needs during the second world war, where radar use founded dozens of applications for instance navigation, aircraft location, enemy ship detection, anti-collision, and weather forecast.
At first radars were designed in VHF and UHF bands, then, after the magnetron development for high power transmission, microwave radars appeared. Most of the radars were using pulse systems based on sending pulses of electromagnetic energy and received reflected echoes from targets. Later the Doppler principles were established to determine the target velocity from frequency variation, to understand if the target is moving toward or away from the radar. With this development, radar had reached its three main detecting functions: range, speed and velocity.
Radar has been continuously developed and extended to a wide variety of object detection and tracking, such as missiles and satellites. This whitepaper entiltes the same development.
