GPS to track car use?

[Lurker]

Is it possible to verify a teenager's use of the family car using a handheld GPS unit hidden in the trunk, for instance? This would be for something like verifying that he/she is going to school or work rather than someplace not allowed. Also possibly to determine if excessive speed is a problem, but this is not necessary.

Would a GPS even work in a trunk without using an external antenna?

I don't want to discuss the obvious violation of privacy issue here, just the technical. Let's assume that some proper disclaimer of limited privacy has been made. The exact method would obviously have to be secret to be effective and sometimes a parent has to make a tough decision. Using an external antenna would not be feasable unless it were almost invisible.

I have never used GPS and I assume what I am asking is easily done, but to do it in secret would be the tricky part. Accuracy would not be important, and I wouldn't expect to be able to track it in real time, but to just verify after the fact where the car was. Also, runtime on batteries might be an issue. It would need to run for at least a few hours (ideally 8-10) and if it goes dead, is the memory lost? Vehicle power is an option, but complicates things and I would like to avoid that.

Finally, I'm hoping a relatively inexpensive ($200) GPS unit would suffice.

Any advice appreciated.

 

[raggie33]

Re: GSP to track car use?

i think car rental companys do that. but im not sure if they still do it.good luck on finding info.i think its a good idea

 

[Frangible]

Re: GSP to track car use?

Many GPSs can get that kind of battery life, but whether or not they can get reception through a metal trunk without an external antenna, I wouldn't bet money on. Alternatively, you could talk to said teenager, which wouldn't be as high tech, but hey.

 

[BIGIRON]

Re: GSP to track car use?

From my somewhat limited experience with GPS. A handheld would not work in the trunk without an external antennae. Essentially, they must "see" the sats. If you do rig it, it can give you a basic ground track but that would not provide exact points and times. This is based on my experience with my basic Magellan GPS. One of the highdollar later models might well have the capability you're looking for. Pretty sure someone around CPF will have better info.

It might be worth it to search for a service provider like OnStar or LoJack -- trucking companies, utilities depts, police depts all use such a service. Might be available on a short term lease.

Then again, it would be cheaper just to hire someone to follow the kid.

 

[Lurker]

Re: GSP to track car use?

[ QUOTE ]
Frangible said:
Alternatively, you could talk to said teenager, which wouldn't be as high tech, but hey.

[/ QUOTE ]

"Trust, but verify" is the philosophy driving my inquiry. Talking is necessary, but only does so much.

Thanks to all for the input.

Could a strand of wire placed inconspicuously serve as an antenna?

 

[Frangible]

Re: GSP to track car use?

I don't know much about external antennas, my GPS does not have one. I'd guess it would be strips of wired plugged into a jack, though. Only a few GPS units have external antenna jacks.

 

[was_jlh]

Re: GSP to track car use?

A piece of wire is not gonna get it, guys. GPS operates in the 1.5 - 1.6 ghz range, if you need to use an external antenna, you'll want one that is made for the task.

 

[Brock]

Re: GSP to track car use?

It won't work though a trunk, but most have features to mark there point at given intervals and then downloaded. They are quite small and maybe could be hid in the rear window?

If you have on-star they transmit the GPS location every 30 seconds or so...

 

[NeonLights]

Re: GSP to track car use?

I've got a good friend who sells GPS units to businesses so they can track their service trucks and other vehicles. They provide very detailed info such as average and peak vehicle speed, and where the vehicle has been at any point in time. I'm guessing one of those systems would be way above your $200 budget though, and would definitely require an external antenna.

-Keith

 

[dg]

Re: GSP to track car use?

Yes units are available that dont require an external antenna or line of sight to the sky. Look for units with a SiRF Xtrac chipset

Here's a link from a UK site which you can use for reference
http://tinyurl.com/4gxn9

or this one http://www.stealth-international.com/

or www.navtrak.net

Various devices normally used as part of a vehicle alarm, and with an inserted SIM card will transmit coordinates to your mobile phone as a text message, on movement or at regular intervals.

Automatic Vehical Locator is something to search for on Google

But if it comes to needing to track your kids, I think the answer is elsewhere.

 

[Frangible]

Re: GSP to track car use?

[ QUOTE ]

Yes units are available that dont require an external antenna or line of sight to the sky. Look for units with a SiRF Xtrac chipset

[/ QUOTE ]

How does this work? I thought radio waves could not penetrate metal at all.

 

[Lurker]

Re: GSP to track car use?

These are some excellent suggestions and it is interesting to see what is available. I don't really need a professional solution and am not on a professional budget, so the suggestion of hiding a handheld GPS unit in the rear window area seems reasonable. Maybe inside some sort of bag or container to disguise what it is.

 

[dano]

Re: GSP to track car use?

The Yellow Cab Company near me uses GPS on the cabs. I've never seen an actual GPS style antenna on the cabs, though (they have small wire antennas on the top for the radio system).

-dan

 

[springnr]

Re: GSP to track car use?

...

 

[4sevens]

Re: GSP to track car use?

Most sedans have a "shelf" behind the back seat -it's usually
some kind of particle board and you can mount your unit under there.

I haven't done it yet, would love to do something like that.

Did you all read recently on the news that some exboyfriend tracked
his exgirfriend with a gps on her car. He kept showing up in odd
places that she was at. He was finally caught by the police when
he tried to change the batteries.

very funny.

 

[chmsam]

Re: GSP to track car use?

I seem to recall an item on (maybe) NPR about a system to do this within th past year or so. IIRC, the idea was not to track via GPS but to keep track of mileage and speed of the vehicle ("Gee, Dad I was only going 35" when the system says 70). This is the type of information that could be used to verify if Junior said he was going to the library (2 miles away) but the feedback says the car went 25 miles. But as I said, I don't recall it being GPS, or not, exactly.

 

[Lurker]

Re: GSP to track car use?

[ QUOTE ]
4sevens said:
Most sedans have a "shelf" behind the back seat -it's usually
some kind of particle board and you can mount your unit under there.

[/ QUOTE ]

My car has that. Underneath the fibre board is metal, but there are a variety of holes in the metal piece. It might be possible to slip it up through a hole from the trunk side, but even the largest holes would be a very tight fit if it would fit at all. Slipping a remote antenna in there would be easier, but the units that accept remote antennas seem to start at around $450, and the antenna is pricy, too.

The rear window has a defroster grid on it. I have read that heated windshields create a problem for dash-mounted reception. Would the rear window defroster grid (assuming the defroster is turned off) prevent reception?

 

[was_jlh]

Re: GSP to track car use?

Lurker, I performed an experiment this morning based on your thread.

I have a Garmin GPS-12 ( does not use external antenna ), a
'92 Roadmaster and a 35 mile commute to work. Cleared the track log
in the gps, set it to take a track waypoint every 60 seconds. The
batteries were fairly fresh. Stuck the gps in the pouch on the
back of the front passenger's seat and headed for work. Checked
it several times during the drive, it always had a decent signal.
When I arrived at work it had recorded approx 40 waypoints. If I
loaded them in something like StreetAtlas, it would show my drive
up I-85.

The only problem I saw was battery usage, the built-in battery gauge
showed that the batteries were down to 75% capacity after the trek.
So that would not handle your 10-hour need. However, you can purchase
a 12-volt lighter adapter for this unit.

Of course, YMMV ( no pun intended ).

Hope it helps.

 

[Lurker]

Re: GSP to track car use?

[ QUOTE ]
was_jlh said:
Lurker, I performed an experiment this morning based on your thread....

[/ QUOTE ]
Thanks! That is very useful information. I don't have a seatback pocket, but a duffle bag on the floor of the car would be easy.

The Garmin GPS-12 is rated for 24 hours of battery life, so I would assume the receiver was working hard and using more power under the difficult conditions. If the unit shut down after a few hours, it would at least record where the car was initially taken, which may be good enough. Is that data stored or is it lost when the battery goes dead? Also do these things start beeping to warn of low batteries? That would not be good.

 

[BIGIRON]

Re: GSP to track car use?

Where's George Orwell when you really need him?