How To Track A Cell Phone

How would one use a cell phone to track another cell phone? I am assuming phone is out of cell tower range. Cell phones are always sending out their location. The frequency is in the range of (I believe) 850 - 1900 Mhz.

Most phones don't have GPS, so tracking is done by triangulating a rough location using the signal strength from several cell towers.

This requires it to be in range of multiple towers.

Originally posted by Nerull
Most phones don't have GPS, so tracking is done by triangulating a rough location using the signal strength from several cell towers.

This requires it to be in range of multiple towers.

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Actually all new phones have GPS, but not all services allows you to use GPS. But, this is not the question.

The question is, "How to use the normal frequency emitted by a cell phone to home in on it using either a cell phone or a scanner. " Using another cell phone would be the best. Think of one cell phone as the "FOX". How can we home in on ithe FOX using another cell phone.

Originally posted by Arnold Roquerre
[Think of one cell phone as the "FOX". How can we home in on ithe FOX using another cell phone.

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You can't. A cell phone can talk to a cell tower, but one cell phone cannot talk to another cell phone directly.

Originally posted by Davel
You can't. A cell phone can talk to a cell tower, but one cell phone cannot talk to another cell phone directly.

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Bingo. Even Nextel with walkie-talkie functions does not go direct between phones.

You need a directional antenna and a sensitive receiver to be able to home in on a low power cell signal - and you may need everyone else to turn off theirs to keep from getting multiple false signals from stray echos.

Originally posted by uncle_vanya
You need a directional antenna and a sensitive receiver to be able to home in on a low power cell signal - and you may need everyone else to turn off theirs to keep from getting multiple false signals from stray echos.

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Can't speak for TDMA/GSM, but even that won't work with CDMA. CDMA uses spread-spectrum technology. Close coupled to a $55,000 spectum analyzer, I can't even see the signal from my cell phone, just an almost imperceptable increase in the noise floor.

I was going to suggest a scanner, but, I believe, cell frequencies are off limits.

A cell phone puts out a lot of rf. There should be a way to home in on.

A cell phone puts out a lot of rf. There should be a way to home in on. [/B]

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I thought the point was that they put out a BIT of RF, quite a small bit, so the batteries last all week.

Maybe 2-mile walkie-talkies and a directional antenna on one as a receiver would work better. Tape the call button down on the one in the rocket (so it keeps sending whatever "ring" it is programmed to send). If you put the receiver in non-filtered mode (I don't know what it's called, but it lets you hear all the background noise) it might work. One problem might be that even on low these tings are so powerful that a directional antenna might not work (especially if you are close), but you might be able to hear a slight change in volume.

So, I'm confused...

If you're trying to track a rocket, why not use one of the telemetry systems out there (Ozark with the ARTS2/GPS or R-DAS also with GPS) or get your HAM license and use something like BigRedBee? These systems are known to work and work well and are not that expensive once you consider the costs of purchasing/modifying existing systems that may or may not work.

-Aaron

Originally posted by Arnold Roquerre
I was going to suggest a scanner, but, I believe, cell frequencies are off limits.

A cell phone puts out a lot of rf. There should be a way to home in on.

Click to expand...

A cell phone puts out a small to moderate amount of RF when in active communication with a tower, and almost none at all other times. It would be almost impossible to track because of this tiny power output coupled with the fact that it uses spread spectrum technology.

Originally posted by heada
So, I'm confused...

If you're trying to track a rocket, why not use one of the telemetry systems out there (Ozark with the ARTS2/GPS or R-DAS also with GPS) or get your HAM license and use something like BigRedBee? These systems are known to work and work well and are not that expensive once you consider the costs of purchasing/modifying existing systems that may or may not work.

-Aaron

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I have four Waltson transmitters, 2 Adept and on Beeline. I don't need any more. I can use GPS on the phone to locate the rocket except in areas where there is no service. I was just wondering if it would be possible to use the phone as a quick and dirty locator. After all, everyone has one attached to their hip so they are fairly ubiquitous. Cell phones have the potential of becoming the all in one Swiss Army Knife of electronics.

The Disney Cell phone looks like it has the capability of locating handsets. You would just send your kid's cell phone up in the rocket.