The Army’s Electronic Magic Shop (Apr, 1960)
The Army’s Electronic Magic Shop
By Thomas E. Stimson, Jr.
TWENTY MILES from Tombstone, Ariz., at an old cavalry post named Fort Huachuca, the United States Army is testing the electronic weapons it will use in the future.
Eighty years ago the troopers at the fort flashed news of Apache raids by heliograph; today the technicians at the huge 160-square-mile Electronic Proving Ground are using single sideband circuits, infrared and even radio reflections from the ionized trails of meteors for communication between units or around the world.
The remote location in southern Arizona was chosen partly for secrecy, partly because the region is one of the best “electronic vacuums” that the Army could find. There are no powerful commercial transmitters in the surrounding desert, no big TV stations that might interfere with the accuracy of the tests.
The 7500 military and civilian technicians under the command of Maj. Gen. Francis F. Uhrhane are not only testing improvements on present equipmentâ€” they are also working on strange new electronic and infrared weapons that may not go into service in the field for another five or ten years.
When I visited Fort Huachuca recently I was told I’d be shown no secret devices and yet I was amazed at some of the things I was permitted to see. Not far from the crumbling ruins of the old Indian scout quarters I watched a new kind of radio station being erected. Technically it’s called “mobile multichannel tropospheric scatter.” A crew pulled a pair of large rubber bags from inside a couple of trucks, then minutes later the bags were installed on top of pedestals and were being inflated into shape.
“These 15-foot rubber dishes are our antennas,” a tech sergeant explained. “The rear surface of each bag is metalized and serves as a parabolic reflector. The inflated bags take the place of the huge antennas the size of outdoor movie screens that are used in the troposcatter network in Alaska.
“We can erect our antennas in a matter of minutes and then we’re in business. We beam high-frequency energy into the sky in the direction we want, and some of the energy scatters downward from the troposphere. We don’t bother about line-of-sight communicationâ€”we can park the trucks in one valley and reach into other valleys as far as 150 miles away. We don’t need relay points and it’s almost impossible to jam us with any equipment.”
Down in the basement of Greely Hall, the post’s new fortresslike command headquarters, I watched a technician operate a computer that can tell amazing things to a battlefield commander. The commander feeds into the machine all the information about his own forces and all the known information about an enemy, plus other data including terrain and weather. The computer analyzes this information and tells the commander the possible courses of action that he might take, and gives the probable results of each. One thing was emphasized to me. The decision and responsibility for what he does are still the commander’s. The machine gives no orders. At nearby Libby Field I watched a plane take off with a long boxlike structure suspended below its fuselage. This was SLAR, the Army’s “side-looking airborne radar” that allows a pilot to fly in safety on our side of the lines and observe deep into enemy territory. SLAR can see farther than a human observer and through darkness and clouds. It spots anything that moves, from a squad of men to a vehicle or moving train.
SLAR is one member of a new radar family that pinpoints moving objects. In its simplest form this kind of equipment produces an audible or visible signal when it detects a moving object, and shows the distance to the object and its direction on a pair of meter dials. The smallest of these radars can be carried by two men and is called the “silent sentry.” It can stand guard 24 hours a day and reports a moving man a mile away.
One of the most close-mouthed organizations at the Proving Ground is the Electronic Warfare Department. Its chief, Col. Walter E. Lotz, Jr., wouldn’t go into details about his department’s job, which has the responsibility of testing countermeasures against the fuze systems of artillery shells and rockets, and countermeasures against infrared and electronic devices.
“Colonel,” I said, “I’ve heard a rumor that we can detonate an enemy’s rocket or artillery shell while it is still far from its target, and that we have a way of preventing an enemy from exploding one of our own proximity-fuzed weapons. How about it?” Colonel Lotz wouldn’t answer but I think I saw a twinkle in his eye.
This spring the Proving Ground is putting a new installation into use, an “electromagnetic environmental area.” The area is 60 miles long and 60 miles wide, centered on Gila Bend. Inside the area the entire electronic array of an Army corps in the field can be simulated, including all its navigational aids, field TV, ground and airborne radar, radio and radar jammers and all sorts of communication circuits.
A modern corps carries more than 20,000 electronic emitters and in addition there are the communication and electronic devices of adjacent units, the Air Force and Navy, and the enemy. The whole electromagnetic spectrum is badly overcrowded.
No one knows what would happen if even a good percentage of a corp’s emitters should be operated at the same time. But it doesn’t take an expert to guess. Cross modulation, harmonics and spurious radiations would occur. Communication would become an unintelligible Babel. Our own proximity-fuzed shells might explode over our own troops. Our rockets might fly in the wrong direction and explode among friendly forces. By upsetting the standard radio aids to navigation the electronic mishmash might cause our pilots to fly into mountainsides after dark.
To avoid such possibilities the Proving Ground is operating individual pieces of equipment against a simulated electromagnetic background in the new area. The idea is to learn whether the background interferes with the device and whether the device in turn interferes with other equipment. The goal is to make all the systems operate in harmony. Otherwise it may be necessary to establish frequency priorities, allowing some devices to operate only when others are shut down.
The Proving Ground is also setting up a corridor 50 miles wide and extending from Fort Huachuca to Yuma on the California border 250 miles away. Here the Army’s new supersonic surveillance drone aircraft are to be tested.
“Are you interested in drones?” I was asked by Lloyd E. Snapp of Combat Surveillance and Avionics. I told him I’d seen plenty of small pilotless aircraftâ€” I knew they could be controlled by radio in line-of-sight distances and that they could take pictures and bring the films back for processing.
“You’re behind the times now,” Snapp answered. “The drones we’re working with can fly long-range missions. After they leave local radio control they fly a preprogrammed flight, changing altitude and direction according to preset instructions, eventually returning to local control.
“Meanwhile, they take pictures. The camera on the drone adjusts its diaphragm according to the amount of light, changes focus automatically depending on the distance to the ground, uses image motion compensation to offset the drone’s speed and also uses powerful flash cartridges for after-dark workâ€”all automatically.
“The drone develops its own pictures in the air and uses an optical transducer to convert the images into electrical impulses that are radioed back to base. Here a receiving camera converts the impulses into finished prints and at the same time produces a transparency that can be looked at in a viewer.
“This all happens in the space of three minutes while the drone may be several hundred miles away and traveling at twice the speed of sound at extremely high altitude!”
He went on to say that another new development is a TV system that doesn’t blur at high speed and so can be mounted in a drone, radioing its pictures back to a viewing tube on the ground. The “side-looking” radar also can be mounted on a drone, as can infrared surveillance devices.
The Army still likes wire telephone circuits for some critical uses, but today is laying wire by helicopter at 70 miles an hour and also by short-range rockets. But for ordinary communication it is turning more and more to radio.
One of the newest innovations is a truck-mounted radio central that serves as many as 18 “subscribers” in a 10-mile radius. The system replaces the usual small wire telephone net and yet provides telephone service. In turn, it ties in with radio trunk circuits to other areas and even to land wires. It serves both fixed and mobile stations.
Recently an official who was touring the Proving Ground picked up the handset in his jeep, punched a series of buttons (that replace the usual dial) and asked radio central to connect him with an officer in Washington, D.C. The call went through as if it were a routine operation, which it actually is.
The next step in improved communication in the field will be automatic electronic switching for either wire or radio nets. Ordinary automatic switching is too bulky and delicate to use in the field, so the Signal Corps is assembling automatic switching equipment that uses printed circuits and transistors. One 2-1/2-ton truck will carry a complete central automatic station that provides instant switching for 200 lines. The equivalent commercial equipment would fill a building many times the size of the truck.
In an atomic war a field commander needs to have exact information about any atomic explosion, whether it is ours or an enemy’s. The nuclear surveillance people at Fort Huachuca have worked out a method that detects an atomic blast at once and pinpoints its location within two miles of ground zero from up to 300 miles away. The method gives an indication of the yield of the blast. Fallout, rainout and the movement of any radioactive cloud can be calculated. Information like this is useful in correcting aim, assessing damage and determining contaminated areas which troops must avoid.
The Army figures that there are more than 74 complicated and time-consuming jobs that can be performed by automation far faster and more accurately than by humans. The tasks range from logistics and the making up of march tables to fire control and target analysis. Interrogation of prisonersâ€”even language translationâ€” quite possibly can be done by machines.
To study these possibilities the Army has installed one of the world’s largest computer centers at Fort Huachuca. This Automatic Data Processing Department is using an enormous IBM 709 digital computer to help design small mobile systems that can move with the troops. Three sizes are envisionedâ€”a large MOBIDIC (mobile digital computer) for major headquarters use, a medium-sized computer that could be transported by truck, and a smaller 87-pound package that fits in the back of a jeep for local jobs.
“Aiming a battery of guns might be one typical problem for the small computer,” Lt. Col. Luther W. Murphy explains. “You feed in meteorology, the barrel life of the guns, obstacles in front of the guns, number of rounds available, location of our own forces, and other data. Within seconds the machine will tell you which guns should fire how many rounds of what type of shells, giving you the elevation and azimuth settings for each gun.
Weather always has been a complicating factor in tactical operations and it’s more important now than ever. Knowledge of local winds is important when flying a drone; information about winds aloft is necessary when launching a missile. So the Meteorology Department at the Proving Grounds is conducting basic research in micrometeorology, the small-scale weather variations that occur in small areas. Soil and vegetation, lakes and mountains and valleys all have local effects. Being able to predict the details of local weather is almost as important as large-scale forecasting.
In still another kind of weather support, a dozen teams from Fort Huachuca are stationed in various parts of the Western Hemisphere from the Greenland ice cap to Puerto Rico to study the effects of extremes in climate on the behavior of munitions, on stored materials and on types of clothing. Lt. Col. Lawrence R. Klar, meteorology chief, never knows what new kind of assignment will be handed his group. Recently they provided information that helped solve the puzzle of why a pilot’s ejection apparatus sometimes doesn’t work when the pilot needs to leave his plane.
It was suspected that the explosive cartridge that operates the ejection apparatus sometimes deteriorates because of the heat that builds up in a plane in hot weather. They found that inside temperatures on a hot day can climb as high as 250 degrees, hotter than boiling water. The answer was pretty obviousâ€”an explosive is bound to deteriorate under a condition like this, and won’t fire when needed. The solution is to replace the ejection cartridges at regular intervals.
Dozens of other projects are under way at Fort Huachuca. Some of the technicians are studying a special kind of night television that provides a good picture under moonlight alone. They are developing in-ertial navigation systems for drone aircraft, and terrain indicators to prevent a drone from flying into a mountainside if it gets off course. Air-droppable and backpack radio and radar jammers are being tested, too. The list is constantly changing.
In these days of intercontinental missiles and space craft a lot of people have forgotten all about the foot soldier. They don’t realize that in the long run it is the troops on the ground that fight the battles and move in and occupy an enemy’s territory. But the Army hasn’t forgotten. That’s why it is developing “futuristic” weapons for possible practical use in the future.