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Show Radar Magical Beam That j Q j Bounces Back on Contact pljm Lightning Calculator Estimates Distances T m Upon Deflection of Electrons; Study r ffM !JU j Of Apparatus Still in Infancy. fMH By BAUKIIAGE News Analyst and Commentator. W.ST Service, Union Trust Building, Washington. I). C. (In a previous article Mr. Baitkhane told some of the little known facts in the history and development of radar and recorded many of its possible peacetime peace-time uses. In this article he explains uhal makes radar tick and how it performed per-formed some of its marvelous feats in this uur.) "Impact," a publication of the office of-fice of the assistant chief of air staff, intelligence branch, for the first time lifting the veil which has covered cov-ered descriptions of radar, says succinctly: suc-cinctly: "A radar set Is nothing more than a machine for sending electrons out into space in a steady stream in a desired direction. These electrons travel with the speed of light in a straight line until their energy is dissipated, or unless they bump into something." That bump is important. If a stream of electrons if shot into the air like a searchlight and a plane flies across the stream, the electrons elec-trons which hit the plane bounce back. They bounce right back to a screen in the radar scope and are revealed in the form of a "blip" of light. Just as an echo bounding back on your eardrum ii reflected In the form of a sound. The principle of the real echo ii used In "sonic" location of obstacles obsta-cles ships use It to locate shoals, for Instance. And, recently, it has been demonstrated that bats use the same principle In avoiding obstacles ob-stacles (which they can't see since they are blind) by uttering a tiny "beep," the pitch of which ii probably prob-ably too high for the human ear to catch. Their beep bounces back in time to warn them to duck. But radar's electronic "blip" is better than a sonic "beep." One reason is that an electron moves with the speed of light which Is faster fast-er than sound. 'Echo' Caught On Radar Receiver Perhaps at this point we ought to recall to your minds what an electron is. A short definition of an electron is "the most elementary :harge of negative electricity." Electrons plus protons (the positive charge) are what atoms are made )f and atoms are what molecules are made of and you and I and the universe and all it contains are, as we learned in high school, nothing but various groups of molecules. Ordinarily electrons pursue the tven, if rapid, tenor of their ways well within the bounds of their own itoms. But radar has changed all that. It has made It possible to project those electrons out Into ipace and then, If they hit something some-thing and bounce back, to catch the "echo" on the "scope" of the radar let in the form of a "blip" or blob of light. We can't go Into detail as to how this operation takes place, but we can tell you in a general way. The icope of the radar set Is round. It Is like a map. North at the top, south at the bottom; east to the right and west to the left So that you will know where you are a little light appears on the screen Just shere your set is located on the "map" you are looking at By moving mov-ing the Instrument, you can keep rourself In the middle. If you see mother spot of light on, the screen jp where 12 o'clock would be on vour watch dial, you know there is t plane (or other object) north of ou. If it should be a plane and it vera coming toward you (which the Instrument would reveal) and It Inally appeared right on top of the light that showed your location, rou'd know that there was going to oe a collision. Radar can "see" a ship 30 miles sway and see It In the dark, through a wall of cloud or mist Khlch no human sight could pene-late. pene-late. Different substances give stronger r weaker "echoes" on your screen, aater little or none. Land more, oullt-up areas more than fields. Rocks more than softer surfaces. In addition to locating an object ji relation to the observer (the Iocs-don Iocs-don of the radar set), the distance from the object can be calculated oy the length of time It takes for ihe electrons to reach the object and Jounce back. The elevation (angle of height from observer) and the deflection (how far to the right or .eft) are calculated Just as a sur veyor makes these calculations by observation from two known points. And you don't have to be an engineer en-gineer to do it either it is done automatically by a lightning calculator. calcu-lator. I have stood In awe before these calculating machines, which can "think" more accurately and a thousand times faster than I could figure, and watched how they direet the aim of the turret, waist and tail guns on a B-29. As I said in lust week's article, the enemy has radar, too. The Germans Ger-mans were working on it with investigation in-vestigation and experiment which paralleled ours and those of the British. Brit-ish. In the early days of the war the Germans had receiving sets on high hills along the coast of France. The electron beam, like that of television, tele-vision, moves in a straight line and j since the surface of the earth is curved, this curve gets in the way if the image and receiving set are too far apart. Therefore, land sets are placed as high in the air as possible. We knew that the Germans had some kind of an electronic device and they knew we had one. One of the early commando raids, which the papers said was successful in destroying a German "radio station," sta-tion," really destroyed the radar Installation. In-stallation. Poke Out Jape 'Eyes' One of the reasons why Iwo Jima and Okinawa were so important, besides be-sides the fact that they make excellent ex-cellent naval and air bases, is because be-cause the Japs had their radar detection de-tection stations on these islands and were able to detect the presence of our bombers and intercept their flight. You will also recall that a number of little adjacent Islands that hardly seemed of any importance impor-tance were seized by our troops. In all probability It was because they had radar installations which could detect and give warning of planes leaving the larger Island for Japan. As we put out her "eyes" one after another, Japan becomes more Impotent. There have been many cases, you may have noticed, where the Japs, on land or on small ships, have been taken by surprise. I have no Information on this subject sub-ject but in some cases it may have been due to the fact that they lacked radar equipment It Is believed be-lieved that what radar knowledge Japan has came from the Germans. Of course, there is one phase of radar detection which in the past has sometimes prevented use of data concerning the detection of a plane or ship. That is the fact that until the object Is very close It cannot can-not be Identified. It is merely a "blip" of light. Therefore, it Is Impossible Im-possible to tell friend and enemy apart. Some sort of Identification has been developed, details of which are still. I believe, "top secret." An example of how this worked to the disadvantage of the British was in the engagement in which HMS Hood was lost On May 21, 1941, the Hood was lying in the strait between be-tween Iceland and Greenland when suddenly out of nowhere she was hit by a salvo from the 15-Inch guns of the powerful Bismarck. Tho Bismarck had accurately located the Hood with radar equipment; the first reported successful use of redar In such a naval operation in the war. It is said that the Hood had likewise detected the presence of a ship at the spot where the Bismarck Bis-marck was, but knowing that a number of friendly warships were In the vicinity, did not dare to take the chance of attacking first Many improvements have been made in radar which are not as yet ready for the public eye and all say the study is only In Its infancy. Scientific achievement seems limitless limit-less and the one virtue of war Is that it spurs inventive genius to great strides of progress. When peace comes radar will likewise open new vistas of which the layman hardly dreams. Harry Truman didn't want to be vice president James Byrnes didn't ask to be made secretary of state. Neither wanted to mix Into International Inter-national affairs but they found themselves on the same boat en route to Germany. |