A friend just bought a new car. He said that he could have added a device to allow his car to be tracked if it is stolen, but it would cost about 2 grand!
We thought about it for a while and came up with this idea: the $50 car tracker: why not just keep a cell phone in your car--one of the newer ones where they can track where it is using tower triangulation or GPS.
Cell phones are always in contact with nearby towers, even when you aren't making a call. They have to do this to keep track of what frequency to shift to for the local cell, so that you can receive incoming calls.
You could hide a cheap cell phone somewhere, and have it constantly charging. If your car is stolen, you just call up Sprint, Verizon, or whoever, and ask them to pinpoint your car, then call the police and let them know. You could buy a really cheap service--or maybe a 'friends and family' plan so there is no extra cost at all! To heck with 2 grand!
And if you are ever in an emergency somewhere and forgot your phone or forgot to charge it, just dig out the hidden one! It is always with your car and always charged.-- newt, May 06 2005 Where's my car Phone_2c_20where_27s_20my_20car_3fSimilar idea to find a lost parked car. [newt, May 06 2005] Follow That Cellphone Follow_20that_20cellphone [theircompetitor, May 07 2005] Nextel's mobile locator service http://www.nextel.c...obile_locator.shtmlI'm sure the other services offer this too. [newt, May 20 2005] [newt] I take my hat off to you in utter astonishment - this is a simply very very good idea.-- Basepair, May 06 2005 ... and thus has no business in the halfbakery. What the hell, I'll vote for it anyway.-- justaguy, May 06 2005 How closely can they narrow down where the cell phone is?-- 37PiecesOf Flair, May 07 2005 Why not just have a built in GPS? This is how OnStar locates vehicles.-- waugsqueke, May 07 2005 do it yourself - about 100 meters accuracy get the network operator to help you - as accurate as 10 meters.
What information you can extract from your phone -> - the cell IDs of the 1 or more base stations you are connected to. - the signal strength for each base station
Thus you can get the "cell ID" (i.e. which base station you are closestest to) which gives you accuracy of anything between 100m to a few kilometers.
This is assuming you have a list to decipher which cell ID corresponds to which location. ( like "abc123" actually means the area "palo alto, CA" )
Because you DON'T KNOW where the base station actually is, you only know the area the base station covers, you can't do triangulation yourself. Thus would be impossible for you to chart all the base station and do triangulation yourself. This is more accurate in urban areas where base stations are more frequent.
The reason I go to the length to explain trying to do triangulation yourself is that I tried. The carriers might NOT help you locate it. At least here in Signapore, they would NOT help you. And a think a few years back, before E911, it was ILLEGAL for the telcos to do it. Not quite sure what the situation is now, it would be good if they allow it in the US.
If they do, and since they have all the information on where exactly their base stations are, they can calculate for you up with accuracy as good as 10m.
why NOT GPS? because that is expensive. like 2 grand kind of expensive, which is why this post is here to begin with. ( this kind of system usually includes other anti-theft measures, a pure GPS device which u can track from the web costs u about 600 bucks )
we have a better idea - see my next post --- darius, May 07 2005 So, could this also work where you can locate your car using GPS? I always seem to have trouble locating my parents car in the carpark, so having it on my mobile phone would be really useful (if I have a mobile phone, or course, which, unlike the millions of other children, I don't...).-- froglet, May 08 2005 If you need to use a mobile phone to remember where you parked your car, you have bigger problems the phone can't solve.-- Mr Burns, May 09 2005 random, halfbakery