I meant this, Finnish technology beats F-35's stealth โ detects it from almost 400 km away!
Finnish technology beats F-35's stealth โ this is how it really works (no magic, just smart listening)Imagine: An F-35 is built to be almost invisible to active radar โ it reflects almost no radio signals back. But Finnish Saab in Tampere has built something completely different: the Sirius Compact L24R. It is not a radar that sends out signals. It is a completely passive sensor โ it just listens. Here's how it works in practice: It sits on masts, windmills or tall buildings (easy installation, 65 watts, no cooling required).
It listens for electromagnetic signals from aircraft and ships โ especially their own radars when they are turned on.
An F-35 (or other stealth plane) can be as invisible as you want to normal radar stationsโฆ but as soon as the pilot turns on his own radar to search for targets or navigate, it screams out like a neon sign in the dark.
The L24R is extremely sensitive and focuses on a narrow sector (120 degrees per unit). Three of them provide 360-degree coverage.
It pinpoints the direction with less than 1 degree accuracy โ significantly better than previous versions.
Range: up to almost 400 km on strong radar signals.
In short: Stealth works against active radars that are watching the plane. But against a passive listener who just sits and waits for the plane to โtalkโ to its own radar? Then it's done. Product manager Pekka Halme explained it bluntly:
"We can detect signals better than with the tactical systems because we only look at a certain sector." That's why the system has already been sold to 10 countries - and why Russia (and China) sweat a little extra when Finnish masts suddenly appear along their borders. The irony? You build an aircraft for hundreds of millions of dollars that is supposed to be invisible... and then a Finnish white box comes along and says "hey, we can hear you anyway". Want more details on how they distinguish different radar signals or how it works with Starlink drones and electronic warfare? Let me know!
Why it's so effective against stealthStealth technology is about reducing reflected radar energy.
Passive tracking doesn't care about reflection โ it picks up what the target plane itself emits.
Result: An F-35 can be "invisible" at 100โ200 km to regular radar, but is visible at almost 400 km to a good passive sensor as soon as it uses its own radar.
Brief summary:
Passive radar tracking is like standing quietly in the dark and listening for the enemy's flashlight. The enemy thinks it's invisible โ but as soon as it turns on the light, you know exactly where it is. That's why Finnish masts with Sirius Compact have already been sold to 10 countries and are making both Russia and China sweat along their borders. The irony? You spend hundreds of millions on a stealth planeโฆ and a white Finnish box on a mast says "hey, we can hear you anyway".