Alternatives to Mechanical Encoders

Recently I posed a question titled "Replicating an Encoder" in which I asked for and received a lot of valued support in identifying the optical encoders in an existing system. The purpose in asking was so I could replicate the encoder environment elsewhere.

This new string is similar in that I again wish to measure angular movement with precision but without using conventional optical encoders and the gearing mechanisms they require.

The idea that this might be easy came to me while I was using a digital vernier.

Obviously, there is no lack of precision in that environment which apparently uses some magnetic method for calculating changes in registration.

This is not an Optical or a Bar Code environment either, as I once suspected as many of my verniers have nothing on the surface of the moving slide. This suggests a magnetic sensing system.

You are all familiar with them, I am sure.

The question is simply this:

if I

1.> can wrap a similar magnetic strip onto the surface of a degree wheel of a rotating shaft, such as on a telescope. . . .

2.> position the "reader" above it as is done on digital verniers

Is it practical to attempt to translate that information into a digital readout that displays absolute movement in degrees, minutes and seconds of angle from some baseline or fixed datum?

What words do I use when using a search engine to find these devices?

Are these considered linear encoders?

What I find interesting is that all the verniers I use will shut off automatically when not in use but will still know exactly where they are when awakened.

That's not something possible with optical encoders used in telescopes now which must be reset using at least two known targets.

Thanks

L.J.