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To understand why there is always some disagreement whenever a flying saucer is picked up on radar, it is necessary to know a little bit about how radar operates.
Basically radar is nothing but a piece of electronic equipment that "shouts" out a radio wave and "listens" for the echo. By "knowing" how fast the radio, or radar, wave travels and from which direction the echo is coming, the radar tells the direction and distance of the object that is causing the echo. Any "solid" object like an airplane, bird, ship, or even a moisture-laden cloud can cause a radar echo. When the echo comes back to the radar set, the radar operator doesn't have to listen for it and time it because this is all done for him by the radar set and he sees the "answer" on his radarscope--a kind of a round TV screen. What the radar operator sees is a bright dot, called a "blip" or a "return." The location of the return on the scope tells him the location of the object that was causing the echo. As the object moves through the sky, the radar operator sees a series of bright dots on his scope that make a track. On some radar sets the altitude of the target, the object causing the echo, can also be measured.
Under normal conditions the path that the radar waves take as they travel through the air is known. Normal conditions are when the temperature and relative humidity of the air decrease with an increase in altitude. But sometimes a condition will occur where at some level, instead of the temperature and/or relative humidity decreasing with altitude, it will begin to increase. This layer of warm, moist air is known as an inversion layer, and it can do all kinds of crazy things to a radar wave. It can cause part of the radar wave to travel in a big arc and actually pick up the ground many miles away. Or it can cause the wave to bend down just enough to pick up trucks, cars, houses, or anything that has a surface perpendicular to the ground level.
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.
These are but a few of the effects of an inversion layer on radar. Some of the effects are well known, but others aren't. The 3rd Weather Group at Air Defense Command Headquarters in Colorado Springs has done a lot of work on the effects of weather on radar, and they have developed mathematical formulas for telling how favorable weather conditions are for "anomalous propagation", the
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two-bit words for false radar targets caused by weather.
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 radar-scope. Many times a weather target will be a fuzzy and indistinct spot on the scope while a real target, an airplane for example, will be bright and sharp. This question of whether a target looked real is the cause of the majority of the arguments about radar-detected UFO's because it is up to the judgment of the radar operator as to what the target looked like. And whenever human judgment is involved in a decision, there is plenty of room for an argument.
All during the early summer of 1951 Lieutenant Cummings "fought the syndicate" trying to make the UFO respectable. All the time I was continuing to get my indoctrination. Then one day with the speed of a shotgun wedding, the long-overdue respectability arrived. The date was September 12, 1951, and the exact time was 3:04P.M.
On this date and time a teletype machine at Wright-Patterson AFB began to chatter out a message. Thirty-six inches of paper rolled out of the machine before the operator ripped off the copy, stamped it Operational Immediate, and gave it to a special messenger to deliver to ATIC. Lieutenant Cummings got the message. The report was from the Army Signal Corps radar center at Fort Monmouth, New Jersey, and it was red-hot.
The incident had started two days before, on September 10, at 11:10A.M., when a student operator was giving a demonstration to a group of visiting brass at the radar school. He demonstrated the set under manual operation for a while, picking up local air traffic, then he announced that he would demonstrate automatic tracking, in which the set is put on a target and follows it without help from the operator. The set could track objects flying at jet speeds.
The operator spotted an object about 12,000 yards southeast of the station, flying low toward the north. He tried to switch the set to automatic tracking. He failed, tried again, failed again. He turned to his audience of VIPs, embarrassed.
"It's going too fast for the set," he said. "That means it's going faster than a jet!"
A lot of very important eyebrows lifted. What flies faster than a jet?
The object was in range for three minutes and the operator kept trying, without success, to get into automatic track. The target finally went off the scope,
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