[_s]

> The best GPS resolution available to civilians is about 8 meters (26 feet) - and that's under the best, most ideal situation using the best GPS receiver and a large antenna... things a small cell phone in a pocket or bag doesn't have.

I am not sure where you got this from but that is incorrect - the accuracy (or resolution) depends entirely on the number of satellites and/or augmentation systems you're tapped into, and how strong / clear those signals are. It can vary from a few kilometres down to a few centimetres.

Back in the 90's "Selective Availability" was a thing but it has since been removed.

See https://www.gps.gov/systems/gps/performance/accuracy/

Also - most modern phones can and do tap into the major providers (Galileo, Glonass, GPS etc), towers, WiFi spots, beacons and use all of these to give a a VERY accurate position of where the device is.

Edit: Might mention I worked first hand on indoor tracking of users, and a warehouse project for optimising worker picking - we were able to easily distinguish where a person was in a busy retail setting down to which section of a clothes rack they were selecting clothes from, and exactly where a worker was in a very interference-heavy (metals) warehouse floor using the above mentioned technologies.

[Alupis]

From your link:

> For example, the government commits to broadcasting the GPS signal in space with a global average user range error (URE) of ≤7.8 m (25.6 ft.), with 95% probability. Actual performance exceeds the specification. On May 11, 2016, the global average URE was ≤0.715 m (2.3 ft.), 95% of the time

Which assumes clear skies and good line of sight... Neither condition exist inside your pocket or house.

Regardless, none of the technologies you listed are accurate enough for police to legally search a person or their home simply because some tech company says a device is located around some dot on a screen.

PS: Your warehouse tracking thing is interesting, although I think you'd of had an easier time tracking gyroscope/accelerometer senor data.

[ViViDboarder]

From your quote:

> Actual performance exceeds the specification. On May 11, 2016, the global average URE was ≤0.715 m (2.3 ft.), 95% of the time

[Alupis]

Did you read nothing else? That is the best possible case, as measured by someone's particular device under ideal conditions - which simply do not exist for a cell phone or a device in a pocket, backpack, or house.

Civilian grade gps receivers often do not have large antenna, can track only a few active satellites at once (often only processing 3-4 satellites even if they are aware of 20 or more) and only receive a single frequency of signals instead of both available frequencies. You want your device to be thin, right?

All this means your stolen cell phone, in someone's pocket inside of a building is going to have horrible resolution, unless it augments it's position data with other sources such as realtime cell tower triangulation or is in a really dense, previously observed wifi area... which are things not available to these tracker devices.