alt Hacker NewsJust thinking out loud: given that we know positions of these satellites, is one able to use it for non-gps navigation? Either by using vision - by tracking or by using some electromagnetic specter - listening to satellites...
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gspr • today at 8:21 AM
Sure, if you're able to accurately determine angles between the Earth's tangent at your location and the satellites. That's how you'd navigate using the sun, moon and stars. I suspect those natural celestial bodies are much less of a hassle than man-made satellites.
This contrasts greatly with actual GNSS – the whole point of GPS and the others is that you don't need to determine those angles. The only thing you need to determine is the signal delay (i.e. distance) from a few satellites. That's a lot more convenient.
Not an expert but I imagine the problem with using vision is the problem of angular error propagation. That is the angle-> distance error problem:
linear error≈Rtan(Δθ)≈RΔθ
Here linear error is the error in position, R is the distance from the observer to the target and θ is the angle error. You would need incredibly good optics and resolution to minimise angular error and thus linear error.