[Terr_]

Random thought: If you stick a very small adhesive mirror to the outside window before boarding, then footage "looking down" at the regularly-spaced railroad ties could contribute to information about the current speed and acceleration.

Well, on a straight section anyway, if you turn, the inner/outer edges will appear differently-spaced...

Wouldn't do anything positive in terms of suspicious staff though. They might think it's like some kind of heist-movie that will involve a specialized glass cutter making a circle on the window.

[rnewme]

Why not just use phones GPS?

[Terr_]

In the presentation they mention they are using GPS, and also an accelerometer.

[fhars]

In a Faraday cage?

[trillic]

with any view of the sky multi-band gps is damn good these days, my watch gets good locks through airplane windows even in the middle seat. In aluminum 737s, not compostite frames.

[brainwad]

Train carriages, especially older ones, often have metallic windows so they are even worse than a typical plane. Even right up against the window, with the phone directly against it I have failed to get any lock on some trains.

[fnord77]

and then paint certain ties white and other black, now you have the world's biggest barcode