Where Is Starting RA/DEC With Synscan?

Discuss what equipment, AP Software, AP Apps you are using.
Post Reply
hatflyer
Mars Ambassador
Articles: 0
Offline
Posts: 131
Joined: Sat Jul 30, 2022 2:27 pm
1
Location: US
Status:
Offline

Where Is Starting RA/DEC With Synscan?

#1

Post by hatflyer »


How does Synscan set it's current location coordinates on start-up? It's not DEC=90, RA=0? I think that's what NINA assumes. When I opened Synscan it would not give those RA/DEC values. I think once 1 was 30 degrees. I thought Synscan would assume the camera is roughly polar aligned.

With NINA it assumes it starts at DEC=90 AZ=0, but Synscan with it's non-PA coordinates I think throws that off.

Also, I tried to star align to see if I could resolve this, but when it slews to the target and I need to alter the scopes direction, I do not get a button to confirm the altered aim. The only option is the Back button. So it seems nothing was accomplished with that.

Any ideas?

Thanks.
User avatar
KathyNS Canada
Co-Administrator
Co-Administrator
Articles: 0
Online
Posts: 2584
Joined: Thu Apr 25, 2019 11:47 am
4
Location: Nova Scotia
Status:
Online

TSS Awards Badges

TSS Photo of the Day

Re: Where Is Starting RA/DEC With Synscan?

#2

Post by KathyNS »


When Dec is 90, RA is meaningless. It won't be assuming that combination.

I assume, by "Synscan", you are referring to some polar alignment gizmo? Synscan is SkyWatcher's brand name for their goto system, built into their GEM mounts. Synscan mounts (and, I presume any polar alignment gizmos bearing the name) assume at startup that the Dec is 90 and the counterweights are in their lowest position. That corresponds to an hour angle of +6 or -6. The RA values for those hour angles will vary over time, which is why RA is not useful.
Image
DSO AP: Orion 200mm f/4 Newtonian Astrograph; ATIK 383L+; EFW2 filter wheel; Astrodon Ha,Oiii,LRGB filters; KWIQ/QHY5 guide scope; Planetary AP: Celestron C-11; ZWO ASI120MC; Portable: Celestron C-8 on HEQ5 pro; C-90 on wedge; 20x80 binos; Etc: Canon 350D; Various EPs, etc. Obs: 8' Exploradome; iOptron CEM60 (pier); Helena Observatory (H2O) Astrobin
hatflyer
Mars Ambassador
Articles: 0
Offline
Posts: 131
Joined: Sat Jul 30, 2022 2:27 pm
1
Location: US
Status:
Offline

Re: Where Is Starting RA/DEC With Synscan?

#3

Post by hatflyer »


KathyNS wrote: Thu Sep 15, 2022 4:36 pm When Dec is 90, RA is meaningless. It won't be assuming that combination.

I assume, by "Synscan", you are referring to some polar alignment gizmo? Synscan is SkyWatcher's brand name for their goto system, built into their GEM mounts. Synscan mounts (and, I presume any polar alignment gizmos bearing the name) assume at startup that the Dec is 90 and the counterweights are in their lowest position. That corresponds to an hour angle of +6 or -6. The RA values for those hour angles will vary over time, which is why RA is not useful.
So no assumption on the AZ value? Not near 0 or 360, just anywhere?
User avatar
KathyNS Canada
Co-Administrator
Co-Administrator
Articles: 0
Online
Posts: 2584
Joined: Thu Apr 25, 2019 11:47 am
4
Location: Nova Scotia
Status:
Online

TSS Awards Badges

TSS Photo of the Day

Re: Where Is Starting RA/DEC With Synscan?

#4

Post by KathyNS »


hatflyer wrote: Thu Sep 15, 2022 4:44 pm
KathyNS wrote: Thu Sep 15, 2022 4:36 pm When Dec is 90, RA is meaningless. It won't be assuming that combination.

I assume, by "Synscan", you are referring to some polar alignment gizmo? Synscan is SkyWatcher's brand name for their goto system, built into their GEM mounts. Synscan mounts (and, I presume any polar alignment gizmos bearing the name) assume at startup that the Dec is 90 and the counterweights are in their lowest position. That corresponds to an hour angle of +6 or -6. The RA values for those hour angles will vary over time, which is why RA is not useful.
So no assumption on the AZ value? Not near 0 or 360, just anywhere?

If you are polar aligned, then, with a Dec of 90 and the counterweights down, the AZ would always be zero. But if you are doing this in order to do a polar alignment, the best you can say is that the AZ should be close to zero before you start.

[edit]I looked it up. I am guessing that you are referring to the Synscan App. In its manual, it says, "In order to ease subsequent setup steps, before you power up the mount, you should move the mount by hand into a particular pose, called the home position. " Home position is the position I described: 90 degrees Dec and counterweights down.
Image
DSO AP: Orion 200mm f/4 Newtonian Astrograph; ATIK 383L+; EFW2 filter wheel; Astrodon Ha,Oiii,LRGB filters; KWIQ/QHY5 guide scope; Planetary AP: Celestron C-11; ZWO ASI120MC; Portable: Celestron C-8 on HEQ5 pro; C-90 on wedge; 20x80 binos; Etc: Canon 350D; Various EPs, etc. Obs: 8' Exploradome; iOptron CEM60 (pier); Helena Observatory (H2O) Astrobin
User avatar
SkyHiker United States of America
Local Group Ambassador
Articles: 0
Offline
Posts: 2293
Joined: Sat May 11, 2019 8:40 pm
4
Location: Santa Barbara, CA
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Where Is Starting RA/DEC With Synscan?

#5

Post by SkyHiker »


Can you set the hour angle instead? That should be 6 in the home position. RA then follows from your location and local time.
... Henk. :D Telescopes: GSO 12" Astrograph, "Comet Hunter" MN152, ES ED127CF, ES ED80, WO Redcat51, Z12, AT6RC, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S with OnStep, AVX, Tiltall, Cameras: ASI2600MC, ASI2600MM, ASI120 mini, Fuji X-a1, Canon XSi, T6, ELPH 100HS, DIY: OnStep controller, Pi4b/power rig, Afocal adapter, Foldable Dob base, Az/Alt Dob setting circles, Accessories: ZWO 36 mm filter wheel, TV Paracorr 2, Baader MPCC Mk III, ES FF, SSAG, QHY OAG-M, EAF electronic focuser, Plossls, Barlows, Telrad, Laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: KStars-Ekos, DSS, PHD2, Nebulosity, Photo Gallery, Gimp, CHDK, Computers:Pi4b, 2x running KStars/Ekos, Toshiba Satellite 17", Website:Henk's astro images
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

Return to “AP equipment / AP Software & Apps”