Odd auto-centering behaviour

Sequence Generator Plate Solving
1

So I think I have configured the plate solving tab using PlateSolve2 and the Astrometry Local ANSVR options, and they seem to work.

However, when I build a sequence, and the sequence commands the Mount Centering on Target, The mount slews to around 80 or so pixels from the target, then takes a plate solve shot, then it actually moves the mount 500 or so pixels farther away from the target after the first solve iteration. On subsequent iterations it more or less moves back toward the centering by approximately 10 pixels or so, until the maximum number of iterations is reached, then fails, as it cannot get the mount within the 50 pixel error threshold I specified. This seems like it’s got to be something simple I’ve missed. Has anyone else seen this behaviour?

Thanks,
Marty

2

What mount are you using? I’ve seen similar results when someone using a mount model that doesn’t agree with the plate solve results.

Maybe do a solve and sync first?

3

Thanks for the note. I’m using a G-11. I’ll try the solve and sync first idea too!

One other thought I had was that I see on the PlateSolve2 dialogue window that the default lat long is quite different from my observing site. I’m wondering if maybe the plate solver is not updated with the correct location information and maybe that is throwing it off?

4

I had something similar with my mount lately. If that continue to happen switch Sync behavior to Target Offset.

5

I’ll give that a shot too. I was wondering about what Target Offset was for…

Thanks,
Marty

6

At one point I had a similar issue with my iOptron CEM60. The solution was to clear the mount alignment model using the hand controller. Apparently, iOptron kept overwriting the sync corrections if the controller contained an alignment model. Once I cleared the alignment model, plate solves and syncs worked every time.

Fred

7

are you using EQMOD ?? If so there is a whole tutorial in the help files about how to use SGP and EQMOD.

8

Hey Dennis,

Interesting. No I’m not using EQMOD, I have a G-11 so I use the ASCOM Gemini driver. Is it possible to use EQMOD with a G-11/Gemini 1?

Best,
Marty

9

Thanks Fred,

That’s a good thought. I’ll look into clearing any models that may be floating around in Gemini, just in case.

Best,
Marty

10

I don’t know if you can use eqmod with your mount , I will do some research to see .

11

I found this http://gemini-2.com/faqG1.php It sounds like it might work, it is ascom compliant to be sure.

12

Yep, that’s what I use right now. It has a very full-featured (sometimes too full-featured for me, I think!) ASCOM driver which SGP uses to communicate with the mount.

Thanks for digging around and looking!

Best,
Marty

13

This behavior is a currently undocumented beta feature designed for closed loop centering on a target without syncing the mount. This is only useful if your mount does not support external sync or gets angry when external apps attempt to alter its model.

14

As a reminder I am still patiently hoping that a beta update will allow my scope and others finally to be able to centre accurately. As it is the centering does not converge for cge pro and as a result I cannot use many of sgp’s features - and I can only do one object at a time.

I have described a centering approach that works well and likely will work well for most mounts.

Frank