Why hasn't Russia disabled the key tool that helps Ukrainian weapons hit their targets?

GPS is helping Ukraine hit more targets

The damage to the strategically located Antonovsky Bridge in the southern Ukrainian city of Kherson showed the power of a precision strike. Traffic on the bridge, one of two main routes into and out of the city across the Dnipro River, was cut off on July 27 following a Ukrainian offensive as Kiev struggled to retake Kherson.

Illustration: Alamy

The Ukrainian military attacked the position with missiles launched from the US-supplied HIMARS multiple rocket launcher system, which relies on the Global Positioning System (GPS) to find its target. GPS is a powerful tool of war, but it can be easily disabled by Russia. What is stopping Russia from blocking the GPS system in Ukraine?

The NavStar Global Positioning System was developed by the US Air Force in the 1970s. It was the first system to provide precise positioning anywhere on Earth. GPS receivers receive signals from satellites and decode them using trigonometric calculations. GPS can operate in all weather, space, and temperature conditions.

GPS-guided munitions have all but replaced unguided bombs in the U.S. arsenal. Many other weapons systems, from missiles to artillery shells, are also equipped with GPS guidance. Much of Ukraine’s Soviet-era arsenal does not have such advanced technology. However, the U.S. and its allies are increasingly supplying Ukraine with GPS-guided missiles, which, while expensive, are virtually guaranteed to hit fixed, known targets.

In fact, the GPS system is vulnerable to attack. The global positioning system satellites orbit the Earth at a distance of 20,000 kilometers, but its transmitters are only as bright as a car's headlights. Weak signals can be drowned out by radio transmitters operating at the same wavelength. Some transmitters are harder to jam than others. Military GPS receivers often use "M-code," which is a signal for military use only. Some receivers have filters that separate the signals from background noise and directional antennas that select only signals from satellites.

US weapons, such as the HIMARS rocket, also have a backup inertial guidance system that kicks in if GPS fails to guide the missile.

Why Russia hasn't disabled GPS yet, despite its full capability

Still, Dana Goward, president of the Resilient Navigation and Timing Foundation and a former member of the U.S. government’s GPS advisory board, said Russia could do more to prevent precision strikes from Ukraine. He said Russia has not yet launched GPS jamming to avoid a potential conflict with NATO.

First, a high-intensity jamming device could make it an easy target to detect. Additionally, some Russian forces may be using GPS instead of GLONASS, Russia’s own global navigation satellite system similar to GPS. The Kremlin is therefore limiting GPS jamming to avoid disrupting its own forces.

Russia has the capability to completely disable the GPS satellite system, but it is unlikely that it would take such a drastic step just to thwart Ukrainian attacks. An attack on GPS could be seen as an attack on the United States, risking drawing NATO into the conflict.

In fact, to counter the threat, the US has long been developing alternatives to satellite navigation technology. In June 2022, Washington tested a system called RATS on a B-2 bomber. Most of these systems use onboard radar to find a precise location by comparing the ground below to a map, known as terrain contour matching, or TERCOM. This is a guidance system that has been used primarily by cruise missiles for decades.

If Ukraine continues to receive more GPS-guided rockets from the US and UK, the West believes that Russia may step up its efforts to jam GPS systems. However, they say that the satellite-guided munitions Ukraine has so far are hitting their targets with impressive accuracy.