Say what? You can absolutely track all those things, at least here in the US, if they're large enough. No idea what they filter out in Sweden.
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Ubbe
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It is always said in investigations and in the TV program Aircrash Investigation that when the transponder are turned off an aircraft disappears from their radar screens and have to be tracked by military radar. The MH370 flight where lost from radar screens as soon as its transponder where turned off.
/Ubbe
/Ubbe
There's something wrong there. I never followed the story about MH370 but if it was a few hundred miles away from land then it would be lost from the screen to due to the transponder being off and not being received by satelite but that has nothing to do with RADAR.
You can see all manner of things without transponders using ground-based aviation RADAR...birds, people, quadcopters, gyrocopters etc. The techs in the runway caravan use the RADAR to tell when to put the kettle on - as they see the return from anyone walking across the aifield towards them
Any object can dive below the radar horizon and fly 100s of miles away in any direction making it truly lost with regards to final crash location.There's something wrong there. I never followed the story about MH370 but if it was a few hundred miles away from land then it would be lost from the screen to due to the transponder being off and not being received by satelite but that has nothing to do with RADAR.
You can see all manner of things without transponders using ground-based aviation RADAR...birds, people, quadcopters, gyrocopters etc. The techs in the runway caravan use the RADAR to tell when to put the kettle on - as they see the return from anyone walking across the aifield towards them
Ubbe
Member
Wikipedia, among other sources: "Air traffic control uses secondary radar, which relies on a signal emitted by a transponder on each aircraft; At the time that the transponder stopped functioning, the Malaysian military's primary radar showed Flight 370 turning right,"
As I understand ATC do not use or even have a primary radar.
/Ubbe
That would be an incorrect understanding. Wikipedia and Aircrash Investigations aren't necessarily reliable sources.
Again, no idea what they do in Sweden, but here in the US, ATC absolutely has primary and secondary radar.
Yeah. Primary surveillance radar for air traffic control is all land based with a range of about 60 nautical miles or (110 km). Once an aircraft is beyond that range, as was the case with the Malaysian Air flight, controllers rely on secondary surveillance radar (ADS-B/C, Mode S, etc). But controllers absolutely have conventional radar available to them, with more range and better resolution than ever.
Ubbe
Member
I read about that, that their primary radar they use have a much higher frequency for better resolution and are used at the airport area and close to it for approach/departure and the higher frequency then have a much shorter coverage range.
/Ubbe
As with VHF and above then it is all line of sight. Height, earth curvature all have their part to play. Also I gather the airport primary radars are honed to cover a specific sky area under the airports ATC traffic control responsibility. Bit like using wide, medium and narrow beamed torches with the same light power. All affects image resolution, range, etc.
All depends. There are different types of radar used in aviation. The long range ones will easily go to several hundred miles with no obstructions.
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