So the NSA can track any cell phone on the planet, but not any on Malaysian Flt 370?

reply to post by stumason


No, Secondary radar sets, which a lot of ATC radar is literally can't see it.

Primary radar, some ATC and all military, will see the skin return with no altitude or other data.

Secondary radar on the other hand can only "see" the transponder codes. It sends out a coded radio signal that the transponder responds to. Shut off the transponder and there is nothing for it to see.

All Primary antennas have a Secondary antenna, but not all Secondary antennas are Primary antennas.

The Nsa collect data from phones that are connected to networks, making calls and sending texts. There is very little 'network' to connect to out over the ocean, so therefore not really possible to miraculously locate the passengers phones.

There may be some phone data whilst the flight was still in range of towers but that wouldn't be much help if the plane went into the sea hours later.

reply to post by Zaphod58


Surely then, describing a secondary "radar" as a radar is misleading? If what you say is true, then it is just a bog standard radio system whereas radar, as the name suggests, is for "detection and ranging".

From what I have read, an SSR does the basic job of radar in addition to the transponder working in tandem to provide much more accurate information on altitude and aircraft ID. It still does, however, do the basic job of a radar system.

Of course, if I have been misinformed, I bow to your knowledge Zaph, but if so then they really need to change the name. It's like calling two cups and a piece of string a telephone!

PlanetXisHERE
I thought the NSA had the capability to pinpoint the location of any cell phone on the planet, and this is the capability that is public knowledge, I'm sure the real capability goes beyond that.

Only if the cell phone is on the network. On a plane, most of the phones will be in airplane mode or off. Can't track them at that point.

Also, they were at altitude over the ocean. No towers in range.

PlanetXisHERE

Meldionne1
Wouldn't the batteries have run down by now? ...i mean I have to charge my phone every few days.

It is often been said how these devices can be tracked even when the battery is turned off.

Then it's been often said incorrectly. Who said it? Why would you think this to be true? NSA can find your phone's location either by asking the tower to ask your phone where it is (usual) or by interrogating your phone directly. Basically, hey, where do you think you're at? and your phone gives back the GPS readings. But that only happens if GPS is on, you're in range of a tower, and the phone is operating at least on standby.

loveguy
power stuff through the air wirelessly

Somewhere, can't remember where exactly, but I found one can send up to 5 vdc wirelessly to power a remote device. Negating the need for battery?

There's not an "up to 5vdc" limit. It's not dc at all. There's a way to wirelessly charge things, but only if the area's outfitted with a near field radiator (bulky) and the phone's got the near field charger back end (they don't).

FirePiston
reply to post by PlanetXisHERE

 

Can't believe we wasted billions on the stealth fighters/bombers when all that needs to be done is hit a switch on the transponder to go invisible.

Depends on what you're trying to be invisible TO. An ATC radar may not know you're there if you don't have the transponder working. Military radar returns a lot more info and doesn't give a rip about the transponder.

As far as that goes, there used to be a way to feed targets to the more common ATC radars from the field by exploiting a soft spot in the software, I assume you could remove one that way but possibly not.

reply to post by stumason


SSR is tied to PSR antennas for terminal control at the airport. But it also operates independently in some areas, for enroute control. Aircraft are slowly switching to Mode S, which doesn't require the SSR codes, and will give more information.

This is a PSR with the SSR tied into it.

This is an MSSR without the PSR antenna.

reply to post by Zaphod58


Fair do's

I still think calling it a "radar" then is akin to slapping a bow on a turd and calling it beautiful though!