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Automation of meridian flip

Posted: 08 Sep 2021, 03:27
by jauunton
Hi all,

I am looking for a way to automate imaging sessions when the target crosses the meridian.

What I need to happen is the sequence/script detects the flip starting, stops the guider, waits for the slew to complete, takes a test shot, plate solves, re-centers the target, restarts guiding, waits for a settle and then re-starts the imaging sequence. Anybody done this? I use PHD2 for guiding but can use the AA guiding routines if that makes things easier.

Regards

John

Re: Automation of meridian flip

Posted: 08 Sep 2021, 16:32
by Iver
For flip detection you could use "Guider.LostStar" in your imaging script. If it returns True then have the script go to a sub script that starts with a pause long enough to be sure the flip has completed. Then takes an image, solve and sync to the image and GoTo your target. re calibrate your guider and start imaging. I've never tried this but it seems like it could work, there are script commands for all the tasks.
Good luck!

Re: Automation of meridian flip

Posted: 09 Sep 2021, 16:00
by fabdev
To detect the current side of the mount, for ASCOM telescopes, it will be released (but it's already included in AA7) the script function:

Telescope.PierSide

which returns 0, 1, -1 following the ASCOM standard:
https://ascom-standards.org/Help/Platfo ... erSide.htm

Just try:

Print Telescope.PierSide

Re: Automation of meridian flip

Posted: 09 Sep 2021, 22:52
by jauunton
Thanks...I have AA7 so I will try that....

Re: Automation of meridian flip

Posted: 01 Jan 2022, 12:14
by Deapsky
Hello AA users,

here are some simple routines to find out if a flip is necessary or not:

azlimit ist the limits where my mount can go without a flip.
The telescope give back it RA and DEC position, together with the position of observation I can calculate the azimut position.

RA=Telescope.RA
DEC=Telescope.DEC

azlimit_east= 170
azlimit_west= 190

lon= 6.75
lat = 51.5

az,al = EquatToAltaz(ra,dec,lon,lat)

Print RA;" ";DEC
Print lon;" ";lat
Print az;" ";al

pierside=telescope.pierside

Print Pierside

Print (az-azlimit_east)

If (az-azlimit_east) > 0 and (az < 180) then print ("Flip --> West possible")
IF (az-azlimit_east) < 0 and (az < 180) then print ("noFlip --> West")

If (azlimit_West-AZ) > 0 and (az > 180) then print ("Flip --> East possible")
IF (azlimit_West-AZ) < 0 and (az > 180) then print ("noFlip --> East")
Hope it is useful

Clear skies
Peter