Radar

“ One would immediately think that since the ground or a house isn’t moving, and a car or truck is moving only 40, 50, or 60 miles an hour, a radar operator should be able to pick these objects out from a fast-moving target. But it isn’t as simple as that. The inversion layer shimmers and moves, and one second the radar may be picking up the ground or a truck in one spot and the next second it may be picking up something in a different spot. This causes a series of returns on the scope and can give the illusion of extremely fast or slow speeds. ”

“ Below you in that great forest will be thousands on thousands of splendid boys, ready, if need be, to give their lives for their country when the big push comes. And here you are, with radar eyes that can see in daylight or dark, clouds or sunshine, three hundred miles or more. When enemy planes come this way looking for those boys, you’ll know. ”

“ Then there was the fact that radar clocked it at 1,400 miles an hour. The F-94 was heading straight for the star Capella, which is low on the horizon and is very brilliant, but what about the radar contracts? Some people said “Weather targets,” but the chances of a weather target’s making a 180-degree turn just as an airplane turns into it, giving a radar lock-on, then changing speed to stay just out of range of the airplane’s radar, and then slowing down when the airplane leaves is as close to nil as you can get. ”

“ The radar emitted a pencil-shaped beam which detected and locked on to the aircraft. Using target coordinates provided by the FSCC, the controller programmed the enemy position, ballistic characteristics of the bombs, current winds, and other pertinent data into a computer which was connected to the radar. The computer also received inputs from the radar and, in turn, provided corrections in airspeed, altitude, and heading which the operator passed on to the pilot. ”

“ During the Washington National Sightings several people proposed the idea that the same temperature-inversion layer that was causing the radar beam to bend down and pick up a ground target was causing the target to appear to be in the air. They went on to say that we couldn’t get a radar-visual sighting unless the ground target was a truck, car, house, or something else that was lighted and could be seen at a great distance. ”

“ This poor inanimate piece of electronic equipment has taken a beating when UFO proof is being offered. "Radar is not subject to the frailties of the human mind," is the outcry of every saucer fan, "and radar has seen UFO's."
Radar is no better than the radar observer and the radar observer has a mind. And where there's a mind there is the same old trouble. If the presentation on the radarscope doesn't look like it has looked for years a UFO is being tracked.
Radar is temperamental. The scope presentation of each radar has certain peculiarities and an operator gets used to seeing these. ”

“ Schematic view of radar targets on successive sweeps of the antenna.
Radar is not a TV camera or a photographic lens. It does not, at least at present, produce a picture of the physical appearance, shape, size, or color of the thing it detects. The scope shows only tiny spots of light on the flat surface of a screen. A pointer something like a clock hand continually sweeps around the dial at a given speed. A complete rotation may take from two to fifteen seconds, depending on the type of the set. ”

“ As the vessel or aircraft operating the radar approaches the SART location, the blips change to concentric arcs, and within about a mile of the SART become concentric circles, centered on the SART.
Because the SART actively responds to radar pulses, it also informs its user, with an audible or visual signal, that it is being triggered. This alerts the user in distress that there is an operating radar in the vicinity, whereupon they may send up flares or initiate other actions to indicate their position. ”

“ During the early spring of 1952 reports of radar sightings increased rapidly. Most of them came from the Air Defense Command, but a few came from other agencies. One day, soon after the Alaskan Incident, I got a telephone call from the chief of one of the sections of a civilian experimental radar laboratory in New York State. The people in this lab were working on the development of the latest types of radar. Several times recently, while testing radars, they had detected unidentified targets. To quote my caller, “Some damn odd things are happening that are beginning to worry me. ”

“ Sensor technologies are grouped into four areas: active, passive, imbedded, and processing.
Active sensors: By far, the most important of the energy-emitting sensors is radar. Among the best all-weather capabilities of any type of sensor, the role for and capabilities of radar have steadily increased since the Second World War. Radar systems are used for early warning, air defense, air asset management, air traffic control, naval fleet defense, detection and tracking of moving ground targets, missile targeting, missile terminal guidance, terrain data development, and weather prediction. ”

“ As far as radar was concerned, we had reports of fantastic speeds—up to 50,000 miles an hour—but in all of these instances there was some doubt as to exactly what caused the target. The highest speeds reported for our combination radar-visual sightings, which we considered to be the best type of sighting in our files, were 700 to 800 miles an hour.
We had never picked up any “hardware”—any whole saucers, pieces, or parts—that couldn’t be readily identified as being something very earthly. ”

“ This factor in turn causes the chart-like image painted on the scope to differ from the chart of the area.
If the navigator is to be able to interpret the presentation on his radarscope, he must understand the characteristics of radar propagation, the capabilities of his radar set, the reflecting properties of different types of radar targets, and the ability to analyze his chart to determine which charted features are most likely to reflect the transmitted pulses or to be blocked. Experience gained during clear weather comparison between radar and visual images is invaluable. ”

“ This sweep hand keeps pace with the rotation of the radar antenna as it scans the sky by sending out radio pulses. When they encounter a solid object, they bounce off and return to the set as echoes which show as “blips,” or spots of light, on the radarscope. The operator must interpret these spots and try to identify them as planes, helicopters, balloons, ships, mountains, clouds, birds, storms, hurricanes, or phantom echoes of various kinds. Safe commercial flying depends on the accuracy of147 these identifications, as does the security of the country in periods of international tension. ”

“ Radar, of course, will give an accurate measurement of speed and altitude, I pointed out, but radar is not infallible. There is always the problem of weather. To get accurate radar data on a UFO, it is always necessary to prove that it wasn't weather that was causing the target. Radar is valuable, and we wanted radar reports, I said, but they should be considered only as a parallel effort and shouldn't take the place of visual sightings. ”

“ The radar is the only instrument that can give simultaneous range and bearing information to the same object. (A sonar system can also provide bearing and range information, but sonar bearings are far too inaccurate to use in piloting.) Therefore, with the radar, the navigator can obtain an instantaneous fix from only one NAVAID. This unique fix is shown in Figure 811d. This makes the radar an extremely useful tool for the piloting team. The radar’s characteristics make it much more accurate determining range than determining bearing ”

“ But spurious echoes, which sometimes deceive the operator, can also appear on the scope. These “anomalous” or abnormal returns may have one of several causes, including the nature of the radar mechanism itself. To help explain this, let us go back to our analogy of the man in the open field. Let us suppose that the man has mechanized his device. To ease the strain on his vocal cords, he has built a megaphone with a record-playing device. The megaphone rotates automatically and sends out a recorded “Hi!” once every twenty seconds, as regular as clockwork. ”

“ Guidelines for radar settings for radarscope photography are given in Pub. 1310, Radar Navigation and Maneuvering Board Manual. Such photographs, reproduced in the Sailing Directions and Fleet Guides, supplement textual information concerning critical navigational areas and assist the navigator in correlating the radarscope presentation with the chart. To be of the greatest value, radarscope photographs should be taken at landfalls, sea buoys, harbor approaches, major turns in channels, constructed areas and other places where they will most aid the navigator. ”

“ Of these reports, the radar-visual sightings are the most convincing. When a ground radar picks up a UFO target and a ground observer sees a light where the radar target is located, then a jet interceptor is scrambled to intercept the UFO and the pilot also sees the light and gets a radar lock on only to have the UFO almost impudently outdistance him, there is no simple answer. ”

“ Radar is an electronic assembly far too complex for detailed description here, but its basic principle is simple. It is merely an echo machine that reflects radio waves instead of sound waves. To illustrate by a rough analogy, let us imagine that a man is standing in the middle of an open field on a very dark night. He wants to find out something of the contours of the surrounding country but his only tools are a compass, a watch with luminous dial and hands, and a large megaphone. ”

“ Yes, and has sent the boats to the bottom before the Japs knew they were anywhere near.”
“Yes, I know,” said Jimmie. “And I’ve been told that the fellow who caught the first hint of the Jap planes approaching Pearl Harbor was experimenting with radar. And so, what about it?”
77
“Lots about it,” Gale whispered. “Our enemies have radar sets of a sort, but not nearly as good as ours. We have secrets in our radar sets that they don’t know about. You’d find them, the three most important ones, done up in three gadgets,—none of them very large. See this?” ”

“ A radio system which measures distance and usually direction by a comparison of reference signals with the radio signals reflected or retransmitted from the target whose position is to be determined. Pulse-modulated radar is used for shipboard navigational applications. In this type of radar the distance to the target is determined by measuring the time required for an extremely short burst or pulse of radio-frequency energy to travel to the target and return to its source as a reflected echo. Directional antennas allow determination of the direction of the target echo from the source. ”

“ The Board has therefore advocated every practical assistance to pilots transporting the public. The Board believes that aircraft radar has proved to be such an assistance, particularly in modern high-performance aircraft. While it is impossible to predict precisely the action which would have been taken by the captain had the airborne radar been operable, there is evidence to indicate the likelihood that the area of turbulence could have been avoided through the use of airborne radar. ”

“ The sonar kept up a sleepy drone, and radar scopes glowed fitfully with interference patterns, and the warning buzzer beeped softly as the radar echoed back to its receivers the rumor of strange planetary forces that radar hadn't been built to filter through. What made the interference, base technicians couldn't tell, but it practically paralyzed radio communication on all bands, and blanketed out even radar warnings.
The cigarette burned his finger tips, and Harker jerked awake and tried to concentrate on the letter he was writing home. ”

“ Then there was another interesting fact: hardly a night passed in June, July, and August in 1952 that there wasn’t an inversion in Washington, yet the slow-moving, “solid” radar targets appeared on only a few nights.
But the one big factor on the pro side of the question is the people involved—good radar men—men who deal in human lives. Each day they use their radar to bring thousands of people into Washington National Airport and with a responsibility like this they should know a real target from a weather target. ”

“ An instant later, having felt no sensation of acceleration, they were floating weightlessly in the cabin of the little Enterprise.
“The qualities of radar,” Garr Symm said, “exist in their totality in a universe of extension. Time, actually is a drawback to radar, [p 114] necessitating a duration-lag between sending and receiving. Therefore, Ramar Chind, radar behaves perfectly in hyper-space, as you see.”
“Yes,” Ramar Chind said, floating near the radar screen aboard the Dog Star. ”

“ The first problem in analyzing reports of UFO’s* being picked up on radar is to determine if the weather conditions are right to give anomalous propagation. This can be determined by putting weather data into a formula. If they are, then it is necessary to determine whether the radar targets were real or caused by the weather. This is the difficult job. In most cases the only answer is the appearance of the target on the radarscope. ”