With jammers, Iraq is trying to distract American precision weapons. But what can the devices really do

The box is barely larger than a cell phone, costs a few hundred dollars and apparently makes remarkable achievements: It should be able to turn US precision weapons into aberrations.

GPS jammer” are called these jammers, of which the Americans so far have tracked down and destroyed. They block the signals of the “Global Positioning System” (GPS), a network of currently 27 satellites with the help of which the Allies not only control guided missiles, but also troops and airplanes to the nearest meter. If it were possible to permanently disrupt GPS signals, the entire logistics apparatus would be affected.

For example, even before the war, US military expert James Zumwalt warned that GPS jammers could knock out missiles like David once did his opponent Goliat. All nonsense, says the head of the GPS system program, Air Force Colonel Douglas Loverro, against it. There is no jammer “in the store to buy”, which could dazzle a “GPS-guided missile completely.

Theoretically enough, a GPS jammer, as offered by the Russian company Awiakonwersija to disturb satellite signals within a radius of about 200 kilometers. This is mainly because the signals of the US navigation satellites are extremely weak. They reach the antennas of GPS receivers on Earth as an electronic whisper, equivalent to only a billionth of the signal strength with which TV antennas receive TV programs.

Navigation systems, such as those used by motorists, sailors and hikers, are therefore very susceptible to glare from GPS whining. As far more robust, however, applies military navigation device. Because of GPS satellites go out different signals.

The “C / A” code serves civil users. With its help, positions can be precisely located down to five meters. The “P” or precision code is available only to military personnel and has the advantage of pinpointing locations even to a meter.

Air force tests with GPS whine: proven effectiveness

Air force tests with GPS whine: proven effectiveness

The military code is not only more precise, it is also encrypted and can not be easily blocked. He is, Loverro knows from military jammer tests, “a thousand-fold more resistant to interference” than the civil code. GPS jammers would be effective at most within a few kilometers. At least that would affect the accuracy of GPS weapons. But they really did not let themselves be misled.

In addition to satellite positioning, US precision weapons still have a parallel-connected inertial navigation system (TNS). TNS devices are immune to external interference.

To determine the location, they use the inertia of rapidly rotating gyro systems. Here, as at the start of the weapon, the TNS a reference position is entered. If a fighter jet now blocks the steering bomb, the rotating goblin in the heart of the TNS detects any change in the starting position as a kind of disturbance to the rest, allowing it to determine the new position.

Do you dream about the sea as well? Now save up to -70% on your beach vacation.

www.secretescapes.de Distributed by CONATIVE

Military target or block of flats: Quo vadis, bomb?

Military target or block of flats: Quo vadis, bomb?

In the case of GPS weapons, the precise satellite system regularly sends its navigation data to the less accurate inertial navigation – right up to the point of impact. If a jammer now paralyzes the GPS signal, the TNS remains intact and steers the weapon unerringly, starting from the last precise location determination.

Guided by GPS, guided missiles hit their target with a positional deviation of no more than around 3.5 meters. If the inertia control is used, the target deviation increases to values ​​of up to 20 meters. In attacks on military installations, the loss of precision is of little importance. In the case of shelling of inner-city targets, however, these can be the deciding meters, whether a rocket launcher is hit or the dwelling house next to it.