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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

Meridian Flip Configuration

4 months 3 weeks ago
starman345
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Meridian Flip Configuration #49375
Just tried this inside and it seems to perform the flip without any capture taking place. Using Kstars 3.40 01-06-20

-Brian

Kstars-Ekos-INDIE
NanoPC-T4 - Armbian Ubuntu 18.04
iOptron CEM25P mount
Photoline 80mm triplet
ZWO ASI294MC Pro Imaging camera
ZWO ASI290MM mini Guide camera


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4 months 2 weeks ago
RDBeck
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Meridian Flip Configuration #49419
I ran another simulation without capture, and the mount did the meridian flip on schedule. I must have erred on my previous simulation.

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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4 months 2 weeks ago
sterne-jaeger
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Meridian Flip Configuration #49423
OK, good to hear. There are still some seldom situations where at least the simulator does not do the full roundtrip, but I think we have eliminated most of them.

And what about your real hardware? Did you do any dry runs?

- Wolfgang

TSA-120 + FSQ-85 + GSO 150/750 | Avalon Linear + M-zero | Moravian G2-8300 + ASI 1600mm pro + ASI 294mc pro | KStars/INDI on Raspberry Pi 4 with Raspbian 10

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4 months 2 weeks ago
RDBeck
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Meridian Flip Configuration #49441
I haven't been able to make any dry runs with the mount. Hopefully, I'll be able to get some during daylight tomorrow (and image tomorrow night?).

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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4 months 2 weeks ago
RDBeck
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Meridian Flip Configuration #49472
Out with the mount only just now. The target is at +0h 2' + and the mount is on the west side pointing east. However, if the scope were on the mount, it would have already hit the pier. Any suggestions on how to define the mount motion so this doesn't happen? All my issues to date have been with the scope hitting the west side of the pier.

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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4 months 2 weeks ago
ChrisRowland
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Meridian Flip Configuration #49480
That's two minutes - 0.5 degree past the meridian? Had you just done a slew to this position? It could be in the zone where the mount may think it hasn't passed the meridian.

If you can't track two minutes past the meridian then you will have problems with long exposure imaging. Imagine if you are taking 5 minute images. An image starts one minute before you reach the meridian but it won't finish until 4 minutes past and that's the first time that a check can be done to see if a flip is needed.

What i think is needed are hour angle limits. They are:
A tracking hour ange limit. This is the hour angle beyond which the mount must not track. When it reaches this limit tracking is stopped and the acquisition process is paused. Normally this would be well past the meridian, 30 minutes or so, but it could be less, even in some cases before the meridian is reached.
A flip hour angle limit. This is the hour angle which is the earliest that a slew command will do a flip. Normally this is a few minutes after the meridian but some mounts - the Celestron ones for example - can be set to do the flip up to 20 degrees before the meridian.

The flip process should also be managed using the Pier Side property when this is available. At present this isn't used, it uses hour angle. As a result there's a lot of scope for confusion where a mount does a flip earlier than expected and the flip process does another one or, worse, the flip process does one too early. The system now thinks that a flip has happened but it hasn't and it tracks into a hard stop.

Given these things the acquisition process could be made more flexible and reliable. With reliable pier side (NOT simulated, that just moves the problem into the driver) the flip process can be managed correctly and witth hour angle limits things such as mounts with restricted movement can be handled.

I'd have liked to have sorted this out but the complexities and lack of documentation in the Ekos sources make it impractical for a newcomer. I've tried and the majority of my time is spent fighting my way through multiple layers of undocumented code trying to deduce what it's doing. That's not my idea of fun.

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4 months 2 weeks ago
sterne-jaeger
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Meridian Flip Configuration #49497

The flip process should also be managed using the Pier Side property when this is available. At present this isn't used, it uses hour angle. As a result there's a lot of scope for confusion where a mount does a flip earlier than expected and the flip process does another one or, worse, the flip process does one too early. The system now thinks that a flip has happened but it hasn't and it tracks into a hard stop.

Good news, folks, we are starting to work on it. It will make the meridian flip more robust - hopefully - but the code complexity will grow again. Since there are mounts that now their pier side, others not, some can be forced into a meridian flip, others not etc.

- Wolfgang

TSA-120 + FSQ-85 + GSO 150/750 | Avalon Linear + M-zero | Moravian G2-8300 + ASI 1600mm pro + ASI 294mc pro | KStars/INDI on Raspberry Pi 4 with Raspbian 10
The following user(s) said Thank You RDBeck, pug916

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4 months 2 weeks ago
sterne-jaeger
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Meridian Flip Configuration #49498

The target is at +0h 2' + and the mount is on the west side pointing east

That's really strange, but maybe it's simply an edge case. Your mount does not take 2 minutes to slew? Or maybe you were not fast enough checking the hour angle?

The question that I always ask in such situations: are you really sure that date, time and location match 100% between the mount and KStars? Is KStars setup in such a way that it propagates its settings to the mount?

If not, that is a typical source for unexpected behaviour.

Wolfgang

TSA-120 + FSQ-85 + GSO 150/750 | Avalon Linear + M-zero | Moravian G2-8300 + ASI 1600mm pro + ASI 294mc pro | KStars/INDI on Raspberry Pi 4 with Raspbian 10

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4 months 2 weeks ago 4 months 2 weeks ago by RDBeck.
RDBeck
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Meridian Flip Configuration #49503
I don't know if the mount has any information not from KStars. I have confirmed that the OS time and KStars observation location times are on the same time zone and consistent with the location. I have also verified the location is correct. Where do I check that KStars propogates to the mount?

I did have to effectively reset the mount model after the initial test. The mount pointed so far from the first target that plate solving was going through several astrometry files trying to find where it was actually pointed. I stopped the plate solving and slewed to a point nearer the NCP which plate solved well. The following slew was also good with the target in the frame (2 deg x 1.5 deg).

I'll do a similar check later today.

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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4 months 2 weeks ago
sterne-jaeger
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Meridian Flip Configuration #49508

I don't know if the mount has any information not from KStars.

You can the values in the handset of your mount.

Where do I check that KStars propagates to the mount?


In the INDI settings of KStars:

TSA-120 + FSQ-85 + GSO 150/750 | Avalon Linear + M-zero | Moravian G2-8300 + ASI 1600mm pro + ASI 294mc pro | KStars/INDI on Raspberry Pi 4 with Raspbian 10
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The following user(s) said Thank You pug916

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4 months 2 weeks ago
RDBeck
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Meridian Flip Configuration #49519
I had my mount model very screwed up. I think I have it working correctly after going to the defaults, going to park and releasing the RA clutch to get the counterweight bar vertical. Now when the scope slews, it appears to be pointing in the right place plus the hour angle on the Ekos mount tab is consistent with the KStars hour angle.

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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4 months 1 week ago
RDBeck
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Meridian Flip Configuration #49878
Here is a follow-up from a more-or-less successful evening.

I was working on M42 and did a solve and slew at HA ~+1minute. The mount was on the west pointing east at the start of the solve and moved to the east side. However, it would only slew to Alnitak or Alnilam at this point in time (consistent with the display in KStars). After playing around on the Horsehead Nebula (not sure how long), I could successfully move to M42.

Any suggestions?

Hypertuned NEQ-6Pro, ZWO OAG, ASI 120 min guide camera, SV 80ST, ASI 1600MM Pro, ASI filters and filter wheel, DIY Moonlite-compatible focuser, DIY SQM

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