How do people handlle lost guide stars in APT/PHD2? - Forums

Topic starter

Apr 19, 2022

I'm just wondering if there is a way to have APT and PHD2 automatically recover from lost guide stars due to clouds/trees. I live in the UK and the weather is very unpredictable and also my back garden is surrounded by neighbour's trees. Platesolving and Goto++ are working fine for me, so logically there should be a way.

The reason I'm asking is that I am having to periodically check that PHD2 is still locked on a star and guiding correctly and I'd rather not be doing that all night.

Sorry if this is a bit of a novice's question.

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andrea tasselli

Frequent contributor

Apr 19, 2022

Chose a box large enough in PHD2 and it does it all for you. At least it does in my case…

Andy Wray

Topic starter

Apr 19, 2022

andrea tasselli:
Chose a box large enough in PHD2 and it does it all for you. At least it does in my case...

Thank you! I will look into that to see if it helps.

I was particularly thinking about when clouds roll by for let's say half an hour. I know PHD2 may recover eventually, but APT would have carried on taking images with no guiding and, by the time PHD2 recovers, any drift in the mount (and yes my HEQ5 does drift a bit even with good PA) means that it could be somewhat off-target. Just wondering how that problem could be solved?

What comes to mind is some way of pausing the sequence if the guide star is lost for more than XX seconds and then, once guiding is resumed, using platesolving to re-centre the target and resume the sequence.

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andrea tasselli

Frequent contributor

Apr 19, 2022

I doubt APT does that. NINA should be able to, however. At the very least you can script it.

Robert Winslow

Apr 19, 2022

If you allow PHD2 to auto-select the stars, and it looses the one it is tracking, I notice that it uses the next star that is selected. I have had PHD2 keep tracking even with heavy clouds passing over.

andrea tasselli

Frequent contributor

Apr 19, 2022

As I use guiding scopes I rarely loose stars and then only when it's completely clouded out. Which is a bit of an annoyance as the frames are useless anyway when the cloud deck is thick enough to prevent useful imaging but the guiding still goes on.

David Koslicki

Apr 19, 2022

@Andy Wray I use APT to loop on a plan which starts with a GOTO++ and ends with an "execute plan" pointing to the current plan. It will then keep looping like this until the session planning limits (i.e. time limit) kicks in. I keep the number of exposures relatively low (5-10 exposures), that way if anything goes awry, the image is re-centered, PHD2 is paused and a guide star is found again, etc.

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Greg Meyer MD

Apr 19, 2022

I believe Patriot Astro on youtube explains this using NINA. It can check to see if tracking is off, and re-align. I think that would also restart PHD, you can check it out and see. https://www.youtube.com/playlist?list=PLvMGHP27Lbqe7ln5XHGn0XX5JhpT40fkU

kuechlew

Apr 20, 2022

Greg Meyer MD:
I believe Patriot Astro on youtube explains this using NINA. It can check to see if tracking is off, and re-align. I think that would also restart PHD, you can check it out and see. https://www.youtube.com/playlist?list=PLvMGHP27Lbqe7ln5XHGn0XX5JhpT40fkU

Specifically it's this one: Stop Losing Images After Clouds (or Animals, or Poor Alignment, or Bad Tracking, or ...) with NINA - YouTube

Clear skies
Wolfgang

Dale Penkala

Apr 20, 2022 · Edited: Apr 20, 2022

“What comes to mind is some way of pausing the sequence if the guide star is lost for more than XX seconds and then, once guiding is resumed, using platesolving to re-centre the target and resume the sequence.”

(DON’T KNOW WHY MY QUOTING SELECTED DIDN’T WORK!)

I DON’T HAVE THIS PROBLEM IN SHARPCAP PRO. PHD2 IS CONTROLLED THRU SHARPCAPS SETTING UNDER THE GUIDING TAB.

@Robert Winslow IS CORRECT IF YOU USE ENABLE MULTIPLE STAR GUIDING IN PHD2 IT WILL DO THIS AS WELL.

DALE

lorisaare

Apr 20, 2022 · Edited: Apr 20, 2022

You are the best

Connor Kessler

Apr 20, 2022

David Koslicki:
@Andy Wray I use APT to loop on a plan which starts with a GOTO++ and ends with an "execute plan" pointing to the current plan. It will then keep looping like this until the session planning limits (i.e. time limit) kicks in. I keep the number of exposures relatively low (5-10 exposures), that way if anything goes awry, the image is re-centered, PHD2 is paused and a guide star is found again, etc

This ^^^

Getting into this kind of routine with APT has made my short imaging windows significantly more effective and efficient. San Francisco summers seem to have a collective 15 minutes of clear skies so being able to set up and trust that my rig will be able to keep going and make every gap in the clouds productive has been godsend.