How you do guys build a 'mount model', what options do you set in the eQmod tabs and what is your process please?
What I'm trying to do now that my observatory is up and running for good, I want to get the mount slewing to targets as accurately as possible.
At the moment it's a bit off...

No real workflow yet. Always hat problems building a mount model with my dslr, because it did not always get the images solved.
But since i found out that plate solving with the asi is working great i think i will make a new mount model next time the moon is away.
What i did was the option "named stars" and i used 3 star alignment.

cheers
niki

I never build a mount model. I simply rely on plate solving to slew to my targets.

Wouldn't you like to slew to target and have pin point accuracy on first slew?

Well, it would save time which can be used for imaging. On the other hand I usually only image one object per night so I have at most two of these moments (when I start and after meridian flip). So I don’t really mind.

FYI I don’t have a fixed setup and I put it in the backyard when I want to image and take it down next morning. So every time I image I have to do a polar alignment and create the mount model. Since the sequence starts only after end of dusk I don’t want to waste time building a mount model.

I'm not sure about eqmod as I'm a diy sufferer working on the OnStep driver, but I would like to see if modeling would correct for mount speed issues due to ratio corrections. It seems to me that doing the plate solved mount model routine should give you better tracking as well as the goto accuracy. If you look in ekos there's a button for mount model. that will take you to a scripted page. you give it some stars and it plate solves and slews to them, updating your mount each time. I'm pretty sure this is dependent on the driver sending the proper serial command to your model enabled mount to update it. We've been testing such a process for OnStep with mixed results. Testing has been suffering horribly in cloudy weather this year.

Yes that is correct, there is a "Mount Model" button in the Align Tab in Ekos. I wrote that feature about a year ago. First, you set up a series of targets to plate solve on, and it will run through each target, plate solving on each one. It has several features that will let you select certain deep sky objects, stars, or grid patterns to include in your target list, as well as a feature that will sort the targets so the telescope has to slew less to finish the whole set. It also lets you visualize the plate solving plan on the skymap so that you can ensure that your points are spread nicely around the sky.

There are two reasons you might want to use this Ekos feature. One of them is to build a pointing model for a mount that can build complex models such as the Losmandy Gemini System or the Eqmod system. Another reason is to analyze the quality of your pointing model (note that to do this you need to select "Nothing" in "Solver Action"). If you are analyzing the quality of your model, you would probably want to output the data to a spreadsheet file so that you can crunch the numbers.

Please note, this feature is not for everyone. There are mounts that can build complex models with numerous alignment points and the model gets better with each additional point (like my Losmandy). But there are also mounts that can only use a maximum of 3 or 4 points and don't try to correct for too many variables (like my Meade Autostar). Also, even if your mount can build a complex model, you might not really care about doing so, as many people just want to do a couple of plate solves at random locations around the sky and when their slews get close to the target, they find that acceptable.

But if your telescope can build a complex model, it can be really nice to spend a few extra minutes building a nice model to get excellent pointing accuracy, especially if you have a permanent observatory and the pointing model can be reused from night to night. This tool is meant to make that easier by helping you plan out and visualize a series of points that are spread out nicely around the sky since that is really necessary for a good pointing model. It also is intended to make the actual pointing model building process easier by automating it.

Unfortunately for Stephane's original question, I don't know that much about the EQMod mount and the INDI control panel settings for complex pointing models. But my understanding is that the EQMod pointing model that he is thinking of building is capable of a really LARGE number of alignment points.

Thanks and hopefully this helps a little,

Rob

Exciting! One thing I love about opensource development is meeting authors along the way. Thank you for your contribution!
Do you know if building a mount model will effect ratios and therefore improve tracking rates in those mounts that have it? Or is it only going to improve slews?

cheers!
Ray

I've got a skywatcher az eq 6 gt mount. When i buid a mount model can i store it in Ekos to use the next day? Or is it stored in de mount?

Eqmod model work as expected and really improve the pointing accuracy.

I have a mobile HEQ5 and until last year I always run an automated script at the beginning of the night to add about 15 points in the model.
This work fine but this is still insufficient to reach the less than 1 arcmin precision necessary to realign a frame with those of the previous night. So plate solving is still necessary to precisely center the target.
And I find that plate solving and sync work the same if you are at ten arcmin or at one degree of the target.
So now I not do any model, "Sync Mode" is set to "Standard Sync" and "Alignment Mode" to "Nearest Point", the first plate solving correct the home error and then it work fine.

Probably a better mount on a fixed pier can get more benefit of the mount model.

You can store the model data in your computer.
In the Eqmod driver Align tab you have a "Write file" and "Load file" button to save and reload the model.
The file name is set in the field "Data file", the default is ~/.indi/AlignData.xml

A small comment of this excellent feature for which I need your opinion...
In terms of robustness of a permanent setup, adding sync points is a weakness: it is better to start with a deterministic mount model, and use it without modification.
So that when something goes wrong during the alignment procedure, the ability of the setup to abandon the current target and slew to the next is preserved. We perhaps all got in the situation where the alignment enters a weird loop because of a wrong sync point.
Thus the method is, once the model is loaded, to always use a differential goto during alignment, and disable the model reset on alignment failures or job startup.

-Eric