Is GPS too weak? It's so easy to jam that we're in trouble if we don't do something about it!? | Latest technology in 5 minutes | Latest GPS trends
This time, we are returning to the topic of GPS, which we have taken a break from for a while.
Previous articles focused more on the time when the entire industry was very excited, from the birth of GPS to the present.
As for GPS today, GNSS (Global Navigation Satellite Systems) from various countries have all been released, reaching a stage of maturity and becoming a standard technology.
In fact, despite all the attention space development has been receiving lately, don't you find that you rarely hear about GPS?
However, the GPS/GNSS industry has recently become a bit noisy. What exactly happened?
🔍 Recent topics in the GPS world
What kind of things are being discussed in the recent GNSS industry, including GPS?
"Wait, was GPS this 'weak'? I didn't hear about that!"
"Yeah, didn't I tell you? And yet it's being used for incredibly important core systems, so what should we do... It'll be a disaster if something happens."
"Oh, really?? Then we're in trouble if we don't think of a way to fix it."
It's probably something like this...
What are you talking about??
You might think, but the meaning is mostly correct (laughs).
I have touched on this every chance I got in past articles, but...
Actually, this talk about GPS being 'weak' (GPS vulnerability) is not something that just started; it has been discussed for a long time.
Recently, after a certain event occurred, that weakness surfaced as actual damage. It has become clear that we are in real trouble if we don't do something about it.
🤕 When you say it's weak, what exactly is weak about it?
So, what exactly is so weak about GPS?
There are many things, but the weaknesses that are particularly problematic are mainly two.
First, it is simply that the radio waves are very weak.
And second, it is that anyone can use it freely.
The first one is very easy to understand, but the second one... sounds like a good thing, doesn't it?
Let's explain it in order.
🎧 GPS signals are extremely small
GPS satellites orbit in medium Earth orbit, about 20,000 km away from the ground. That is where they send GPS signals from.
20,000 km is half the circumference of the Earth, about the distance from Tokyo to Brazil.
The radio waves transmitted from such distant satellites become about 1/10 quadrillionth of a watt by the time they reach the ground. (By the way, a 'quadrillion' is 1,000 times a 'trillion'.)
Even so, it doesn't really click, does it?
How weak are these radio waves? You know how sometimes your smartphone signal is weak with only one bar?
It is about one billionth of that state.
Actually, you can't simply compare them, but can you tell that it is incredibly small?
The image is like trying desperately to listen to a whisper happening far away.
😫 Threat to GPS ①: Jamming
GPS signals are like that whisper.
If someone speaks loudly nearby, it can be easily drowned out.
And that 'loud voice' is what we call jamming.
It involves emitting interference waves that drown out GPS signals, making it impossible for the receiver to detect them.
The troublesome part is that jamming GPS is extremely easy.
Even without specialized knowledge, you can easily jam it with a palm-sized device that can be bought online for a few thousand yen.
Of course, the radio frequencies used by GPS are protected by the laws of each country (the 'Radio Act' in Japan), so making such a loud noise is a violation of the law.
However, since illegal radio waves cannot be seen with the naked eye, it is not easy to crack down on them.
Moreover, in the case of GPS, even a small amount of interference can affect a wide area, making it difficult to identify the source.
🕵️ Threat to GPS #2: Spoofing
Another threat is spoofing.
As mentioned earlier, GPS is designed to be freely available to everyone.
In fact, there is no encryption or mechanism to authenticate signals at all. Therefore, the receiver has no way to verify the source of the received radio waves.
To put it more simply, the receiver cannot tell if the radio waves it received were definitely sent from a GPS satellite in the sky.
So, even if the person doing the jamming is not in outer space but somewhere on the ground, they canimpersonate a GPS satellite.
In other words, if you transmit fake GPS signals from the ground, you can easily deceive the receiver.
Even if you are actually in Tokyo, you could be told a lie like,
'You are currently in Brazil.'
🚢 This is actually happening
The fact that GPS signals are weak is nothing new.
Damage from jamming and spoofing has occasionally made small news stories in the past.
For example, regarding jamming, there are many cases that are not intentional, such as reports of car navigation systems becoming unusable over a wide area due to a faulty amplifier in a home BS antenna.
However, recently there have been a series of reports of large-scale GNSS anomalies, mainly in the vicinity of Europe.
In the four months from January to April 2025, 123,000 flights passing over the Baltic states were canceled due to GPS anomalies.
Since April 2025, it has been reported that jamming and spoofing are constantly being observed at sea near the Baltic Sea and the Gulf of Finland.
In March 2025, an aircraft carrying the UK Secretary of State for Defence, and in September, an aircraft carrying the President of the European Commission, were reported to have been subjected to GPS interference.
In another interesting development, there were rumors of social media posts appearing one after another in Poland and near the Baltic states saying,
'For some reason, my smartphone navigation is showing a Russian city!'
😨 There is nothing you can do when it is jammed at a national level
The reasons for these are clear.
It is because Russia is jamming drone and missile attacks from the Ukrainian side in the Ukraine-Russia war.
Since GPS can be used all over the world regardless of national borders, when a situation occurs where it is jammed at a national level, unrelated countries are affected regardless.
Moreover, since the opponent is a nation, you cannot just arrest them for being illegal. We are in a situation where we are helpless, with little more to do than protest.
Slightly off-topic, but map information, which is essential for GPS, is actually a rather delicate issue depending on the country.
In neighboring South Korea, Google Maps cannot be used, and in China, Google Maps coordinates are not accurate, so there are cases where there are various restrictions at the national level even before jamming.
Japan is an island nation and isn't affected by other countries, and we don't have those kinds of restrictions at all, so it's hard to imagine, isn't it?
👿 To overcome the weakness of GPS...
Well, in response to these issues, countries around the world are increasingly feeling a sense of crisis, saying,
"We knew it, but relying too much on GPS is really dangerous!"
that.
By the way, as explained in previous articles, it was thought that relying solely on the US-operated GPS was a bad idea, so countries were moving forward with developing their own GNSS, such as Europe (Galileo), China (Beidou), and Japan (QZSS).
Isn't that enough??
you might think.
Actually, these GNSS systems prioritize compatibility so that they can basically be used at the same time as GPS, so if they are jammed or otherwise interfered with, they all fail~.
That's ridiculous...
you might feel, but that's the situation, so the development of alternative technologies is progressing in many areas to ensure we are okay even if something happens to the current GNSS.
📝 Summary
So, this time, as the latest topic on GPS, we talked about how its weakness is becoming a problem.
So what kind of alternative means are being developed?
You might be curious about that, but this article is just an introduction to explain that, and I would like to gradually reveal the full picture in future articles.
Stay tuned!