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Mystery GPS Tracker on a Supporter’s Car

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Re: Mystery GPS Tracker on a Supporter’s Car

#21

Post by livueta »

yborg wrote: post #18

How do these things do GPS tracking from under a car seat? Wouldn't the seat frame and car body basically block the device from acquiring satellites?

I'm not really an expert (corrections welcome!) but having spent some time recently playing with positioning systems:

Most of GPS's perceived suck (in cold boot (TTFF) time, general receptivity) is actually just bad antennas/chips. I bet this thing has a large, possibly active, antenna and a modern, possibly multi-service, gnss module.

As an example, I have some very cheap ~10mm passive antennas that never pull a signal indoors, and some very cheap modules that take >20 minutes to TTFF even with a clear view of the sky. I also have some big chonker 30mms that, with a modern module, have a <2min TTFF inside/in a car/whatever.

Re: Mystery GPS Tracker on a Supporter’s Car

#22

Post by kube-system »

yborg wrote: post #18

How do these things do GPS tracking from under a car seat? Wouldn't the seat frame and car body basically block the device from acquiring satellites?

Apple Maps keeps working fine when I invariably drop my phone under the seat in my car. GPS receivers are pretty good these days and are capable of picking up very weak signals.

Re: Mystery GPS Tracker on a Supporter’s Car

#23

Post by SAI_Peregrinus »

livueta wrote: post #21
yborg wrote: post #18

How do these things do GPS tracking from under a car seat? Wouldn't the seat frame and car body basically block the device from acquiring satellites?

I'm not really an expert (corrections welcome!) but having spent some time recently playing with positioning systems: Most of GPS's perceived suck (in cold boot (TTFF) time, general receptivity) is actually just bad antennas/chips. I bet this thing has a large, possibly active, antenna and a modern, possibly multi-service, gnss module. As an example, I have some very cheap ~10mm passive antennas that never pull a sig…

The antenna in the picture looks a lot like a Taoglas L1 active patch antenna. So an antenna (possibly several, hard to tell if it's a stacked-patch or not), low-noise amplifier, and possibly a Surface Acoustic Wave (SAW) filter.

Re: Mystery GPS Tracker on a Supporter’s Car

#24

Post by g_p »

kn0where wrote: post #5
squarefoot wrote: post #3

Over here in the EU any cellular device should contain a SIM card which must be registered to someone or some company, therefore it can be used to track the owner; is that different in the US? The article doesn't mention any SIM card present. If I discovered such a tracking device in my car I'd immediately look for the card, get its number and find the owner. Also, it would be nice to fool the GPS through a jammer th…

Last I checked, you could activate a prepaid SIM without any proof of identity in the US. We don’t have a national ID card system. Postpaid does involve a credit check.

In addition, these kinds of rules (in countries which have them) almost invariably do not apply to B2B sales, especially for machine to machine communications - at that scale the operator really only cares that they know which customer is footing the bill for the subscription.

At least in my experience many years ago managing an enterprise mobile account, I could have SIM cards and handsets sent out with no name or similar allocated - the name was a nicety for getting the package to the right person, but there was absolutely no verification of anything. The name helped you reconcile the bills, so we had users on the account called "office spare 1" and "field engineer spare". Any customer support had to go through the B2B account.

At scale, an M2M device customer won't be telling the operator anything else about the device or user - the customer will manage allocating subscriptions to vehicles or devices, and won't want to have to deal with their operator for this.

Re: Mystery GPS Tracker on a Supporter’s Car

#25

Post by taldo »

Had they remembered to connect the ground reference for the Bus Pirate, they would've had a much easier time reading the data back :)

OTOH: how is that even legal? I can't fully grasp how privacy is perceived as a sacred basic right in the US, but then they have dealers tracking people's cars for repossession purposes...

Re: Mystery GPS Tracker on a Supporter’s Car

#26

Post by throwaway81523 »

I wondered if they would find a sim card or other cellular subscriber info in the cellular modem. I'd also hope they could tell if the modem was being activated and transmitting when they powered up the device, and maybe drove it around.

As for VOD, maybe it underreported miles driven because the gps stopped working in areas with poor signal.

Re: Mystery GPS Tracker on a Supporter’s Car

#27

Post by guenthert »

kube-system wrote: post #22
yborg wrote: post #18

How do these things do GPS tracking from under a car seat? Wouldn't the seat frame and car body basically block the device from acquiring satellites?

Apple Maps keeps working fine when I invariably drop my phone under the seat in my car. GPS receivers are pretty good these days and are capable of picking up very weak signals.

Is the Maps application getting the position data from GPS alone or rather from accelerometer plus earlier good reading (using GPS or cell tower known position) or some fancy sensor data merging (Kalman filter)?

Re: Mystery GPS Tracker on a Supporter’s Car

#28

Post by dmitrygr »

more_corn wrote: post #11
dmitrygr wrote: post #6

Earlier quoted context omitted.

This is not really deep, TBH. This is 5-6 minutes of work for someone who does this habitually. They didn't even dump the firmware of the PIC running in there to share it for some fun RE.

You should reach out and give them some pointers for next time.

My contact info is public. I am not hard to find

Re: Mystery GPS Tracker on a Supporter’s Car

#29

Post by brettnak »

jmole wrote: post #15

I had a mystery tracker installed in a car I purchased as well: https://fccid.io/2AEB4AMV01/User-Manual/Users-Manual-3928375 The dealer even added a $250 fee to "remove" this device, but I found it was still installed, so I think I ended up footing the bill for the device itself. The device is ostensibly to protect inventory from loss, but it seems like they are incentivizing dealers to leave these in cars to capture…

Where did you find the tracker in the car?

Re: Mystery GPS Tracker on a Supporter’s Car

#30

Post by dontcare007 »

throwaway0a5e wrote: post #14

TL;DR a prior dealership had installed it as part of an anti-theft add-on before selling it to a different dealer who ultimately sold it to the supporter. The investigative effort they put in was quite good.

Dealers do this to aid in repossession in case of non payment.
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