PDA

View Full Version here: : APT and Automated Merdian flip vs TSX and Dome control around Meridan flip


g__day
09-09-2023, 09:08 PM
My latest question to Software Bisque - on Dome getting scope of peir wrong just after an object crosses the Meridan but before a Meridan flip is executed!

I frequently execute Meridan flips when my gear is within or just past the Meridan – say between 2 – 10 minutes either side (and I need to get a better practice on this – and or automate it further in my imaging run. My imaging software does tracks time to Meridan to the minute and it can automate a Meridan flip if I enable it. Now if I am outside a minute or two to Meridan flip and slew the scope in TSX to the same target then scope and dome move and generally always do the Meridan flip; however it may end up with the GE mounts counterweights a tiny bit higher than the scopes level – and as clearly documented by TSX – when this happens the Dome / Scope alignment code gets confused (by side of pier I presume) and for 5 – 10 minutes the Dome won’t be aligned with the mount – so a Closed Loop Slew (CLS) will fail as the dome blocks the image hence an image link must fail.


I watch all this remotely on a Ring video camera and can see if the scope and dome aren’t aligned – meaning that the CLS must fails and I just have to wait about wait for about 8 – 10 minutes. After this time I see the dome solve work correctly all by itself and the dome moves slightly and then I can simply re-execute my CLS and all is very good!

I am wondering if there is any possible way to improve this process of mine – and /or request the TSX Dome / mount solve to smarten just a tiny bit so it does always align scopes and dome – even if the coutnerweights are slightly above the scope!

So either mathematically it is detectable tha I am in this situation with my scope versus counterweights – and hence soveable with a slight improvement to the dome scope geometry algorithm – or else I have to tweak my Meridan flip routine (automated or manual to minise the chance of this occuring too frequently).

So it’s certainly only a minor inconvience but I am curious on knowing if 1) could it be avoided by detection and improvement to the code and/or 2) what are Merdian flip parameters I can leverage to minimse its occurence!
I images on two scopes using SGP and APT simultaneously – either can issue a got to TSX which should trigger a Meridan flip. The folks from the APT forums folk have suggested I try its automated Meridan flips – by enabling it and setting up parameters:
Matt – try Automated Meridan Flip (AMF) enabled with these settings:


“Flip Moment” = 1 minute (this makes sure the mount stays weights-down)
“Delay Flip Move” = 10 minute (this makes sure the mount gets well past the meridian before the actual Flip is executed. The mount driver actually decides whether a flip is required to get to the requested RA DEC, not APT. If this value is too low, the mount will likely slew across the merdian rather than flip)
“Delay is after meridian passing” is selected (this makes sure the Delay Flip Move time is measured from the meridian) Curious as to your ideas and feedback!



Those values sure didn’t work – a few seconds after APT said the object would cross the Meridan TSX move the dome! So 1 minute after flip moment the dome was blocking the camera and APT starts the plate flip with a 5 second exposure and plate solve – which of course fails given its only seeing the dome!


So I will try putting in -2 minutes for Flip Moment and see if that works!

g__day
09-09-2023, 10:02 PM
At least I have APT and TSX plate solves almost agreeing now!

Trying to set up all the Point Craft Settings again - its been a while - switching everything over to ASTAP for image solving now until I am sure I have all the platesolver data bases set up correctly!

g__day
10-09-2023, 02:37 PM
Last mile with TSX - trying to solve I have Dome Geometry correct!

g__day
10-09-2023, 06:35 PM
Trying TSX controlling the Dome directly without POTH

g__day
11-09-2023, 07:23 PM
TSX controlling the Dome - one 1 minute before and after NGC 6334 passes through the Meridan - notice the radical change in dome position as TSX gets side of pier figured out!

g__day
15-09-2023, 09:27 PM
So I am simply working around this now - given Software Bisque don't think they can cater for LX200 mounts not reporting side of peir correctly - which I presume they could do with a simple exception handle - if side of pier is inferred rather than simple read from the driver directly - then don't recalculate side of pier until scope is moved - simple, neat and easy!

My workaround is simple to tell APT to do automated meridan flips - meaning it stops imaging and guiding when an object is within 5 minutes of the meridan until it is has moved 5 minutes past the meridan. Costs me ten minutes of my imaging time maybe once or twice a night - so no big deal at all!

Drac0
16-09-2023, 12:13 AM
At least you've got a method that works to overcome the issue Matthew, better than the frustration you were dealing with earlier.


Cheers,
Mark

g__day
16-09-2023, 06:56 PM
Absolutely true Mark!

One or two thing sI thing Ivo can consider to improve Automated Meridan Flip in APT - that I added to a thread today:

If the image just before the AMF fails - consider checking the platesove coords of the last three images to use that and

Never let the scope crash into the pier - especially from a halted AMF - set a time limit past Meridan crossing - say 10 - 20 minutes max - and if that is exceeded simply issue a goto to your current coordinates - which should cause a meridan flip and restore the mount back to a safe location!