Re: [ATM] Tracking Systems for Astrophotography

[Vladimir Galogaža <vladimir.galogaza@zg.htnet.hr>]

>If a light sensitive device sees that an object in it's field is
>moving and there is firmware designed to prevent movement and
>that logic consists of applying equal and opposing forces, and
>there is a feedback or "loop" circuitry between the sensor
>seeking "null" and the driving force(s), the object should, at
>some point,  cease it's relative movement on the detector and
>achieve a motionless or null state.

In this statement there is "contradictio in adjecto" ( sort of Catch 22).

How can "a light sensitive device see that an object in it's field is
moving" if at some point "object cease it's relative movement on the
detector"

If an error has to be corrected it must be detected, if it is detected it is
there and is nonzero. The gain of  feedback loop must be sufficient to keep
 the error within required limits (Mel said arcsecond or even its fraction)
and not to cause oscillations. Error limit can be reduced to some
degree but it is never zero.

Vladimir.



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