What is this Reeves Resolver?

Hello everyone,
I came across this at an estate sale. With some limited research, it seems like it might have something to do with guided missiles or satellite trajectories. The writing says: Reeves Resolver RS600N. Does anyone have any knowledge about what this is? I've enclosed a pic...

The front mounted dial with the black cylinder seems to be the actual resolver .... here is a model 601 on eBay for $50 some odd dollars ..... https://www.ebay.com/c/4024308980

Revolvers usually just provide a SINE/COSINE output from a single input EXCITE signal

Googling syncro and resolver will provide information.

These things were used for measuring angles and rotary position.
When I last came across one of these things, about 40 years ago, it was used for measuring the rudder position on a ship.

The thing in the box is basically a piece of test equipment which simulates the thing doing the measuring for testing the unit which displays the information, in my case the rudder angle.

JimB

I used to come across resolvers used in the older motion control servo motors for CNC machines.
Later replaced by the quadrature encoder.
Max.

Here is a design test I did awhile back to design my own resolver reader ....

Resolver Test #1

Resolver Test #2

Resolver Test #3

Satellites? Seems rather old for that. Maybe a Sputnik.