Radar is an acronym for Radio Detection and Ranging. The concept is to emit powerful bursts of radio waves
and measure the time it takes for the “echo” to return to the transmitter after striking some object. RADAR has
been around since 1902 and went into full development and research during World War II. Today radar is used
by police to catch speeders and search for things that are hidden underground. Commercial airliners use onboard radar to avoid collisions. Visit this site for more information:
earth.rice.edu/mtpe/geo/geosphere/topics/remotesensing/25_radar.html