AM5 with PPEC Algorithm

[Daniel Heyer]

I have uploaded logs here. my logs

I have made improvements but was getting image one there there was three OK images and then image 2. I believe better calibration helped with later imaging sessions, but I am wondering if I am imaging a target like M81 or NGC 188 should I run a calibration on the actual target because they are so close to the pole? 

While researching what could be causing the above tracking issues I learned the reason why ZWO does not include PPEC with the AM5 mount and this is because the errors are random. Because of the random errors ZWO test every mount before leaving the factory and ships the a report with the mount. The report is also available from the ZWO website. I attached the report for my AM5 mount.

I was going to try the following settings found in this forum:

But now I wonder if I should just use the Hysteresis algorithm knowing that PPEC might not work correctly with an AM5 or similar mount with harmonic/strain wave gearboxes. Is there way to use ZWO test report to improve tracking?

The section called AM5 PE Report at Amateur Astrophotography explains the report.

Thank you,

Daniel

[Bruce Waddington]

Hi Daniel.  I'm sorry, this is a bit of a mess, it unfortunately shows some very bad tracking results, far worse than normal.   I think you should get a measurement baseline with PHD2 to understand what the mount and the associated equipment is doing.  One immediate question is whether your configuration parameters are right - are you using a 327mm focal length guide scope with the ZWO guide camera?  Here's the procedure to follow for getting a measurement baseline:

https://www.dropbox.com/s/zrf0au7jaisvt85/How%20to%20create%20a%20baseline%20for%20guiding%20results%20using%20OpenPHD2.pdf?dl=0

It's very important that you do the calibration near Dec = 0, not clear up at Dec = 60 where you did it in these logs.  That is always true, it doesn't matter where your imaging target is.  When running the baseline tests, do them near Dec = 0 as well.  For the Guiding Assistant test, let it run for a long time, say 15-20 minutes.  After building the new configuration profile for the tests, don't mess around with any of the algorithm choices - use the defaults

The logs show a large amount of rapid guide star movement, up to 10 arc-sec in size on both axes.  This isn't normal at all.  Can you describe your location and whether the scope and mount is subject to vibration from wooden decks, balconies, etc.  Is it possible that you have a fan vibration problem on one of the cameras - that is a well-documented problem with some ZWO cameras.  Are you dealing with nearby hot surfaces like rooftops?  The Guiding Assistant will help to expose these sorts of problems because guiding will be disabled but it will be critical to find the sources and eliminate them.

The calibrations you did produced poor results and you kept getting alerts about that.  You can't afford to ignore these things, a bad calibration isn't going to produce good guiding results.

Good luck,

Bruce

[Daniel Heyer]

Bruce,

Thank you for the quick reply.

I use an off access guider.

I am at the 47th parallel in the PNW and do not have a great view because of trees, clouds, and light pollution. I might be able to get the DEC down around 30.

QHY268c and I am not detecting any vibration.

QHY Polemaster for polar alignment.

I did manage to figure out the guiding assistant before the clouds moved in.

Looks like it is going to be a week or two before the skies are clear enough to even try running a better calibration and figuring out the drift alignment.

Daniel

[wave...@talktalk.net]

Hello Daniel,

I'm not one of the phd2 gurus, so I'm trying to understand your logs.

First question simple - Is your mount set up in equatorial or AltAz?

Cheers,

- Jack

[Daniel Heyer]

It is setup in equatorial. I am just waiting for clear night to run a drift alignment and nice long Guiding Assistant session.

Daniel 

--
You received this message because you are subscribed to a topic in the Google Groups "Open PHD Guiding" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/open-phd-guiding/n2qPaAiTDt8/unsubscribe.
To unsubscribe from this group and all its topics, send an email to open-phd-guidi...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/1e37383d-ed6b-48a3-a8c9-ae6eac2325c1n%40googlegroups.com.

[wave...@talktalk.net]

Daniel said:
It is setup in equatorial.

OK, thanks Daniel.
Earlier you noted:

I am at the 47th parallel in the PNW and do not have a great view because of trees, clouds, and light pollution. I might be able to get the DEC down around 30.

I don't understant what do you mean by getting Dec down to 30°? Your local celestial equator (Dec0°) has an altitude of 47°on your meridian. If you mean your Dec0° is limited to about 30° altitude in the east or west, then Drift Alignment should still work OK. It will certainly improve the polar alignment better the 41arcmin the guidelogs indicate. However, the Calibration was also done far too high near Dec 60°, as Bruce noted earlier.
Good luck.
- Jack

[Daniel Heyer]

Correct, I mean I am limited to 30° altitude.

If I drive to a dark site easily point east or west, but want to figure out and troubleshoot at home as much as I can. Over the next few months I don't get a lot of no moon dark skies when it finally stops raining around here.

Once again thank for all the help. I am just waiting for the rain to stop so I can work on this more.

To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/d93450bc-552a-4649-b941-1b9d27167cc9n%40googlegroups.com.

[mj.w...@gmail.com]

Hi Daniel

From your latest 3rd May Log:

1) Polar Alignment was way out.

The Guide Assistant run reported PA Error = 41.6arcmins.

Did you see that warning ?

Did you try to improve it ?

Needs to be no worse than 5arcmins.

2) The guide cam output was very variable.

Was it cloudy ? 

1 second exposures may be too fast for Off Axis Guiding.

3) Was the final 53 minute run with guiding switched OFF intentional ?

4)  Is your imaging scope's focal length really Focal length = 327 mm ?

It's unusual to OAG a short focal length but not forbidden, so just checking.

I'm not one of the experts.

Michael

Wiltshire UK

[Daniel Heyer]

Next weekend it might be clear enough to test again. The PNW is on its 4 or 5 winter, I have lost cost.

Daniel

To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/df6aade7-2a25-47fb-9864-0b0b174297c8n%40googlegroups.com.