Here "Visibility" is used metaphorically. Something which is physically not visible but can be monitored as if it is present in our line of sight(using technology) Example, GPS trackers fixed in vehicle can track the activities of the vehicle(speed, direction, location etc.) beyond our line of sight. Even though vehicle is not physically present in front of our eyes, we can keep track on movements.
I'm not 100% positive I have understood your question, but I'll give it a shot.
As already commented, "visibility" implies vision, sight, i.e. one of the human senses.
When speaking of GPS, one might utilize the word in a metaphorical sense, to somehow make the functionality of a GPS more intelligible to a non-tech audience, by likening it to "vision".
A wider and more suitable term, in my humble opinion, would be to speak of "perception". Its semantic boundaries are not so fixed as those of sight, hearing, or any other of our senses, so it might just as well be used to connote the reception of some kind of signals by some kind of machine, in a way that's meaningful to it.
Hence, since I take it you're looking for a noun that might be used instead of "visibility", my suggestion is:
perceptibility ( or its sibling perceivability )
Combining either of the two words with the term "GPS" will give you several potentially interesting search hits on Google.
Here's an example that might suit your context:
Satelite perceptibility can be a problem in urban and densely forested locations due to both tall buildings and tree canopy interference with reception.