Go Back   IceInSpace > Beginners Start Here > Beginners Talk

Reply
 
Thread Tools Rate Thread
  #1  
Old 13-11-2020, 10:06 PM
taylorhan (Jialuo)
Registered User

taylorhan is offline
 
Join Date: Oct 2020
Location: Sydney
Posts: 10
EQMOD star alignment problem

Hi there,
This is my third-time try for star alignment for my HEQ5 via ASCOM and EQMOD.
I am very frustrated because of the failure of this very beginning.

Here is what I do, I successfully connect my mount to EQMOD with the correct location, and the mount is in the home position and face to the north. Then I start CDC (also tried Stellarium) and connect to my mount, (double-checked the location is the same) and slew to Jupiter, but the mount always slew to the opposite way to the Jupiter (i.e. Jupiter is in the west, but the telescope point to east).

Thus, I used EQMOD to correct the telescope to point to the real Jupiter position and try to sync, here is the issue "The ASCOM driver reports an error: SyncToTarget() RaDec sync was rejected" (in both CDC and Stellarium) - I think the problem here is the real position of Jupiter is more than 15 degree from the wrong position, but I can not find the reason why it always points to the opposite position to the real position.

Anyone experiences this situation? and can give any advice?
Really appreciated!

Cheers,
Taylor
Reply With Quote
  #2  
Old 13-11-2020, 10:22 PM
taylorhan (Jialuo)
Registered User

taylorhan is offline
 
Join Date: Oct 2020
Location: Sydney
Posts: 10
Here is the problem screenshots
Attached Thumbnails
Click for full-size image (2.jpg)
196.0 KB8 views
Click for full-size image (1.jpg)
162.8 KB5 views
Reply With Quote
  #3  
Old 14-11-2020, 06:11 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 2,936
Firstly donít use a planet to align with use a bright star , more accurate
Important!!! You must be polar aligned before you use EQMOD and Stellarium to navigate otherwise your mount wonít know where itís going, even after a Sync point , you could be 3 or 4 degrees out of polar alignment which too much for EQMOD and Stellarium to create an accurate pointing model
Secondly what are you using to observe your alignment ? An eye piece ? Your laptop with capture software on live view ?
Thirdly you canít rely on the Stellarium or CDC display to align the night sky , you have to align using stars in a centering eye piece or capture software on your laptop screen with your imaging camera
Fourthly , use the latest Stellarium 0.20.3 as its Ascom compliant now , you donít need StellariumScope as a driver anymore , I switched across 2 weeks ago and works perfect with EQMOD ( I have a procedure for this ) you can use the same cable )
Finally, give the Syncan handcontroller method I sent you a try , it star aligns an polar aligns perfectly
Then you can use EQMOD and Stellarium

Martin
Reply With Quote
  #4  
Old 14-11-2020, 06:50 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 2,936
I just read your original post asking for help
Your obviously connected to your mount and camera with your laptop
Donít use EQMOD for your alignment viewing , use a capture software like Sharpcap or APT set on live view so you can see the alignment Star in real time and be able to zoom in on it for more accurate alignment. I use APT and it has a crosshair for Star alignment and a zoom in for accuracy
I still strongly recommend you use the Syncan handcontroller ( with polar alignment routine ) to firstly Star align followed by Polar alignment ) and Sharpcap or APT and your camera to get you alignment first and foremost. Then you can connect EQMOD and Stellarium and start Goto and navigation.

From the start
Set tripod to true south
Level tripod
Fit mount head
Set mount head to home position
Fit counterweights
Fit telescope and all equipment
Balance telescope
Set back to home position
Start Synscan polar alignment routine ( use Sharpcap or APT with laptop and camera on live view)
Polar aligned and back to home position
Connect EQMOD and Stellarium
Goto and navigate using Sharpcap or APT on live view with laptop and camera )

Remember even if your polar aligned , EQMOD and Stellarium may not centre your star or object perfectly, it may still be a 10 to 50 arc minutes out . Syncing stars close to your object then tightens your pointing model to improve accuracy accuracy

Hope the above helps

Martin
Reply With Quote
  #5  
Old 14-11-2020, 06:58 AM
Ryderscope's Avatar
Ryderscope (Rodney)
Registered User

Ryderscope is online now
 
Join Date: May 2006
Location: Glanmire, NSW
Posts: 1,500
Jialuo,

I notice that you say that the mount is in the home position and pointing north? This should be to the south with the home position pointing to the southern celestial pole (SCP).
Reply With Quote
  #6  
Old 14-11-2020, 07:21 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 2,936
Quote:
Originally Posted by Ryderscope View Post
Jialuo,

I notice that you say that the mount is in the home position and pointing north? This should be to the south with the home position pointing to the southern celestial pole (SCP).
Good pick up !!
But Iíve already sent a full blown procedure how to find true south and set the tripod facing south !!!!!!!!
Reply With Quote
  #7  
Old 14-11-2020, 07:29 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 2,936
How to set tripod facing true south below -

Setting up a HEQ5 ,NEQ6 and EQ6-R Tripod
NB: This procedure is based on having your True South line already marked on the ground from a previous procedure ( length of true south line marked on ground approximately 500mm long or alternatively 2 fixed points marked on the ground 500mm apart)
1/ Open your tripod fully out and extend all 3 legs out by about 100mm then lock them
2/ Place foot of front tripod leg marked ďNĒ directly on True South line and roughly line up the 2 rear tripod legs equally spaced in respect to the True South line
3/ Level the base platform of your tripod by adjusting the legs in or out as required .Check level of the tripod base in both north/south and east/west directions using a good quality builders aluminium bubble float level.Level the base as accurate as you can then lock the tripod leg adjusters nice and tight.
4/ Extend out your True South Line along the ground just past the intersection of the 2 rear tripod legs using a string line, aluminium angle or a straight edge. The feet of both rear tripod legs must be equidistant from the intersection of the extended True South Line. When adjusting make sure you only move the 2 rear tripod legs left or right whilst keeping the front tripod leg ďNĒ stationary or pivoting but not moving off the True South Line
5/ Once the 2 rear tripod legs are equidistant from the true south line , the tripod is now set up level and pointing to Celestial True South
6/ Ensure you take care in setting up the tripod and measuring accurately to the nearest millimetre.This will assist the accuracy of your polar alignment procedure.


Martin
Attached Thumbnails
Click for full-size image (A664F885-B09C-4AED-8DB8-CA819CF322C3.jpg)
205.1 KB7 views
Reply With Quote
  #8  
Old 18-11-2020, 04:25 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 2,793
If you are using EQMOD, have you set your site coordinates within EQMOD? If they are in the wrong hemisphere the scope will be running west to east not east to west.

If that is happening it also would mean if you manually slew the mount back to where Jupiter is for instance, the scope is pointing where it thinks is on the wrong side of the meridian the sync will fail. EQMOD won't accept a sync that is on the opposite side of the meridian to where it thinks the scope is pointed.
Reply With Quote
Reply

Bookmarks

Tags
eqmod, star alignment

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:31 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
NexDome Observatories
Advertisement
Bintel
Advertisement
Limpet Controller
Advertisement
Astronomy and Electronics Centre
Advertisement