If you've ever used a smartphone map or watched, as the shipment moves through the tracking app, you used GPS. Many people don't realize, that GPS – America's Global Positioning System – is just one part of a wider family, known as Global Navigation Satellite Systems (GNSS).
Four global satellite systems orbit the Earth. They guide the planes, ships, cars and trucks, as well as tourists, who are looking for a place, where to eat. But they also play a central role in war.
How the satellites tell you, where are you?
Essentially, satellite navigation is a matter of time. GNSS satellites have extremely precise atomic clocks and constantly broadcast two key pieces of information: its exact position in orbit and the exact moment the signal was sent. Meanwhile, on Earth, receivers are like your smartphone, car or scooter, a plane or a ship - pick up these signals, to determine your exact location.
They do this using signals from four satellites, which provide latitude data, longitude and height, as well as one satellite to smooth out any synchronization errors. GNSS technology is highly accurate and fast. It is deeply rooted in everyday life. But it also has a hidden fragility.
"Signals from global navigation satellite systems are quite vulnerable", Dana Howard told DW, president of the Foundation for Sustainable Navigation and Synchronization in the USA. "They are extremely weak, and this means, that any radio noise near their frequency, accidental or malicious, may interfere with reception", said Howard. "I am sure, that there are people in every government, who understand the problem. The task is to, that the management understands the risk and acts to reduce it".
Four world navigation powers: USA, Russia, Europe, China
The first two global navigation systems were developed in the 1970s, during the Cold War between the United States and the then Soviet Union. The US developed GPS, which became the first satellite navigation network, which has reached full global coverage. This is the most common navigation system in the world. Around the same time, the Soviet Union developed GLONASS.
Then, when in the early 2000s the European Union decided, that relying solely on GPS makes Europe too dependent on US strategic infrastructure, he started building Galileo.
China's BeiDou system is the newest of the four networks. As in Europe, Chinese military planners wanted to reduce their reliance on American GPS.
These four systems are very similar and are "dual-purpose" - designed for civilian and military purposes.
«GPS, GLONASS and Galileo use very similar orbits with a similar number of satellites at altitudes of approx 19 000 to 23 000 kilometers", said Malcolm McDonald, Professor of Satellite Engineering at the University of Strathclyde, Glasgow, Scotland. "BeiDou augments its system with higher altitude orbits to maintain local coverage over Asia".
Each system can send signals to any point on Earth at any time, even to devices, like a wristwatch. Most devices use several constellations of satellites. Japan and India have and operate similar systems, but their systems do not cover the entire planet. They only provide regional navigation data.
How global navigation systems are used in war?
The armed forces are increasingly dependent on satellite navigation for logistics, mapping and operational planning. They are used to aim weapons, in particular, cruise missiles and so-called smart bombs. The military also uses navigation satellites to control drones.
Satellites became a target.
In military conflicts, navigation systems are affected by "jamming" and "spoofing" (signal switching). Spoofing is more difficult than jamming, but it is more effective. “Your navigation system may show, that you are moving at speed 400 nodes and depart from Helsinki airport, when in reality you are in a car, which moves with speed 120 kilometers per hour outside Berlin", said Thomas Whittington, an electronic warfare analyst at the Royal Joint Institute of Military Forces of Great Britain.
This technique is used to hide the location, Russian shadow fleet, which tries to pass through a certain region and remain undetected. "Spoofing was also used to derail ships during their passage through the Strait of Hormuz, which led to an erroneous violation of territorial waters and arrest", said McDonald.
Howard said, that it is potentially a greater threat to Europe and the United States, than for Russia and China, as they have “internal ground systems to supplement and back up GNSS, which the West does not have".
For now, no technology exists, which would effectively neutralize the negative impact on GNSS, Whittington said. Attempts are being made to develop technological alternatives to GNSS, but for now, according to Whittington, one of the "most practical" options in war is "simply tracking down the jammer and destroying it".
Source: https://www.dw.com