How does radar and the Doppler system work?
Radar, like sonar and seismology, uses a man-made pulse of radio energy to map distance based on the length of time it takes the pulse to return from the source. Radar (short for “Radio Detection And Ranging”), which can be airborne or space borne, has greatly changed the way we see the land and ocean surfaces. Radar is based on the principle of sending very long wavelength radiation (called microwaves) from an antenna, and then detecting that energy after it bounces off a remote target. The wavelength of the microwave, its polarization (vertical or horizontal orientation) and strength can be controlled at the source and measured when it returns. Many common land-cover types and materials affect the polarity and strength of the radar return differently, which helps in their identification. The concept of using radio waves to detect objects goes back as far as 1902, but the practical system we know as radar began in the late 1930s. British inventors, aided by research from other countri
