Re: PXP Model


Ross Salinger
 

Thanks Don, that's very useful. One thing confuses me. His write-up mentions the idea that there's a recommended ecuatorial and a recommended set for out the Azimuth mounts. Looking at the GUI four point XP by Dave Rowe insightec as I am right now I don't see any indication of what the correct side of terms might be. I do see that even with every single term calculated in the car that we have the sensitivity is 141. That's much less than 300. So my assumption is we have a good model regardless of what it might be doing. If you think of any way that you can share with me or with the group about pxp, I'd love to see it. Again thanks for the write-up it's very interesting. On a slightly different note in the configuration file undermount parms. there is a checkbox that says track only siderio. I'd love to know whether that means only use the encoders and ignore the model or where there's there's something more subtle going on. If that's a way to ignore the model for tracking but use it for pointing that would really be an ideal case. Thanks for getting back to me again again regards Ross

On Oct 15, 2017 5:34 PM, "westergren@... [SiTechservo]" <SiTechservo@...> wrote:
 

Hi Ross,

Yes it does two ways.  First the basic PXP corrections are applied to the RA and Dec to correct for the various errors that the PXP model detects when you build the model.  Then second, as you track, those errors change as you move to different Alt-Az positions, so over time there will be additional corrections.

Don W



---In SiTechservo@..., <rgsalinger@...> wrote :

Does the PXP model in my system alter the RA and / DEC when the scope is tracking? I understand that it works when the scope is slewing to give me excellent pointing but I'm wondering if it also move the mount a bit when the mount is tracking.


Rgrds-Ross


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