Re: Guide star lost after dithering
|
Roland Christen
Mounts will be instructed to move by two different methods. One is by coordinate moves, the other is by timed move where a 1 second move command corresponds to a 15 arc sec move. Coordinate moves are tricky because they are subject to a different protocol and can cause problems when the mount is in counterweight up position. Timed moves are preferred for all guide and dither commands. I cannot tell by the log below which one is being used. Delta RA = .61 means nothing to me, but perhaps our PHD gurus can clarify.
Rolando
-----Original Message-----
From: Roland Christen via groups.io <chris1011@...> To: main@ap-gto.groups.io <main@ap-gto.groups.io> Sent: Tue, Nov 23, 2021 8:44 pm Subject: Re: [ap-gto] Guide star lost after dithering A dither move is normally the same as a guide move command, except typically bigger. If the mount guides normally and properly, then it is responding to the PHD external commands in the proper manner. I don't see how the mount would, on its own, move the Dec axis by 12 pixels unless instructed to do so.
If the camera is angled by 45 degrees then both X and Y will move although only RA is commanded to move. We don't have enough information at this point as to what really moved. Did the Dec actually move or did the Y axis of the camera move? The two are not the same. People often mix up the X and Y axes, thinking they are the RA and Dec axes. This is not the case unless the camera is exactly rotated to a null position with respect to RA and Dec. That is usually never the case.
Rolando
-----Original Message-----
From: Brian Valente <bvalente@...> To: main@ap-gto.groups.io Sent: Tue, Nov 23, 2021 8:30 pm Subject: Re: [ap-gto] Guide star lost after dithering Regarding your image download when exposure complete, are you still guiding while image is downloading? Does download take a while?
On Tue, Nov 23, 2021 at 6:28 PM yanzhe liu <liuyanzhe@...> wrote:
-- Roland Christen Astro-Physics -- Roland Christen Astro-Physics
|
|
|