Our radar for law enforcement follows in a long history of innovation ranging from military to civilian inventors.
Learn how police radar came to be.
Radar began with the man who came up with the concept for the physics principle that radar operates on: Christian Johann Doppler, an Austrian physicist and astronomer who wrote a paper on the determination of motion using the frequency of light in the study of the movement of stars.
His discovery in 1842 was dubbed the Doppler Principle, the concept defining how radar determines speed. Of course there were no radars in that time, but his principles created the foundation for radar development many years later.
By the 1930s, scientists had noticed when ships passed between radio transmitters some of the signal reflected back to the source. A team of scientists headed by Sir Robert Alexander Watson-Watt developed the first radar in 1935 utilizing this discovery and building on the Doppler Principle.
In light of the threat posed by Nazi Germany, Great Britain built a series of 21 radar towers 90 miles from London along the coast facing France and Germany.
In 1940 the Nazis started a series of bombing raids on England. They knew that an invasion would only be successful if they could establish air superiority. At the time the Luftwaffe had 2,400 planes while the British only had about 600.
However, the 21 radar towers called the Chain Home Network gave the British a decided advantage. The radar would alert the British of an incoming attack 100 miles before the Nazi planes reached the coast. This allowed the British to get their citizens to shelters and scramble fighters, giving them an edge.
Also in 1940, British scientist Taffy Bowen traveled to the United States with design plans for radar. To avoid suspicion he traveled as a tourist onboard the cruise ship, the Duchess of Richmond.
In the United States he joined with US scientists at the campus of MIT in Cambridge, Massachusetts, where they established the Radiation Laboratory, or RAD-LAB. The lab worked closely with the military on over 100 different radar projects. The United States Military supplied test sites for the radar field experiments since they had not yet entered the war.
In 1941 that changed. On December 7th, 1941 an Army radar site detected 353 planes approaching Hawaii. The information was passed up the chain of command but not acted on, resulting in the devastating attack on Pearl Harbor, forever changing not only the US's position on the war, but their position on radar intelligence as well.
Throughout the war, many different applications of radar were introduced. Air-to-ground radar was developed and placed in aircraft. Ship-borne radar was developed as well. Both of these technologies aided in the winning of the war.
The most notable was the sinking of the German warship, the Bismarck. On May 26, 1941 the Bismarck sunk the British ship, the HMS Hood. The British aircraft carrier Ark Royal had ship-borne radar and for 30 hours they were able to coordinate a pursuit of the Bismarck, sinking it in a 24 hour barrage of gunfire.
Radar played a very important role in World War II and because of the urgency of the war, decades of research was compressed into a few short years.
After the war, Winston Churchill noted that the atomic bomb may have ended the war, but radar won the war.
From 1945 to 1950, radar took off in many directions. The United States Military developed radars with better range, capable of making determinations of the size and weight of a target. One of the major accomplishments was the military coupling radars with a computer to track objects and correlate information.
The National Oceanic and Atmospheric Administration of the United States developed and advanced weather radar. Radar also found its way to law enforcement.
In 1955, Bryce Brown, a university professor with experience working on the Manhattan Project, started Muniquip (short for Municipal Equipment). He made speed timers by stretching two hoses across a road, and soon began manufacturing the first law enforcement radar.
In 1964, Brown left Millikin University to focus on his radar company. A Toronto firm was interested in his other products, and bought them along with the company name two years later. Brown kept the radar portion, and renamed the company Decatur Electronics, Inc.
Police radar began as an analog system using a needle rather than a digital readout. Digital technology was not far behind though, and along with it came moving radar.
Since then, radar technology has become firmly embedded as a law enforcement tool. Today radar is employed by the military, and in law enforcement, weather, aviation and sports.