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Meade, Please Let Me Override Your LS North Align!

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#1 astrogeoguy

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Posted 14 March 2012 - 02:23 PM

:help:An open plea to Meade's Lightswitch engineers. :help:

Last night I took my LS-8 out to a public outreach event in a parking lot in Richmond Hill, ON. The sky was beautifully clear and dark in all directions.

I set up my LS-8 about 20 feet from the last row of cars and powered it up. It performed flawlessly until the North alignment step.

The scope swung around to north, stopped, made the small motions to pinpoint magnetic north, then adjusted itself for true north. I stood behind it and watched it carefully aligns itself a good TEN DEGREES off Polaris, which I could easily see above me! After that, the 2-star alignment failed to find Sirius, then Rigel! I eventuially carried out a manual 2-star alignment with huge azimuth shifts required to center each one.

Normally, the scope works beautifully, but this incorrect north fix is a major flaw in the process, and occurs at home and at public events.

Please, I beg you, give us a new firmware revision with the ability to accept or adjust the find north determination! It's a few lines of code! It only needs to give me 20 seconds to decide before it proceeds automatically.

I love this scope! This fix would, I'm quite sure, make these scopes far more reliable for suburban users, and result in far fewer RMAs from frustrated owners.

I look forward to your response. Thanks in advance.

#2 astrogeoguy

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Posted 14 March 2012 - 06:59 PM

Just to make sure I'm being clear - the Lightswitch's horizontal OTA slews in azimuth to find the local magnetic North, then slews by the amount required to correct for the local difference between local grographic and magnetic North (in my case, 10.5 degrees west). At that point, the OTS azimuth should be nearly exactly the same as Polaris'. If I stand behind the scope and soght towards Polaris, the OTA is way off left or right depending on the local magnetic interference. Then it slews up towards the first alignment star, but the entire foundation of the auto-align is compromised at that point.

Chris

#3 Tempe

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Posted 15 March 2012 - 04:49 AM

Hmm. I would never thought that Meade uses North alignment in this "full-auto" LS series. I believed that North alignment is an obsolete feature of first-generation GoTo systems. Personally, I had the same unpleasant experience with small ETX-80. After using Nexstar SE (which doesn't require pointing North or tube leveling) it was kinda new to me to use a compass,and check local magnetic deviation before observing session. And, after all these tricks, the scope veered away from proposed alignment star for at least 8 deg. And so on. I hate North align!

Now it's pretty interesting to compare these two full-auto Goto's from Meade (LS) and Celestron (SkyProdigy). They may (or may not) have different logic of self-alignment.
Clear skies,

Serge

#4 astrogeoguy

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Posted 15 March 2012 - 10:40 AM

I personally think that Meade's determination of local magnetic North is highly accurate. It's that local sources of magnetic interference (including some steel elements on tripods, vehicles, etc.) perturb the local magnetic North direction.

Walk around your property with a compass and see for yourself. I just want to be able to correct for that.

Chris

#5 ChrisHall

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Posted 20 February 2013 - 03:29 AM

I've had my LS-8 for a week now - fantastic telescope. But I've noticed the following about its North alignment process:
- The tube aligns very, very carefully and consistently 10 degrees East of North (declination is 2 degrees W where I live so I'm not worrying about which North!)
- It then looks, typically, for Rigel; aligns about 10 degrees East of it, and says it can't find it...
- BUT it then says it'll try again, and slews about 10 degrees West, and finds it.

It would be absolutely great to know a bit more about how the software works. I get the impression that this is a sort of last-ditch correction for a badly aligned sensor, based on previous successful manual alignments - but equally, I might be reading too much into this.

Any thoughts would be welcome...

#6 ChrisHall

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Posted 20 February 2013 - 03:37 AM

I've had my LS-8 for a week now, and am absolutely delighted with it - AND have been exceptionally fortunate with clear skies, which are pretty rare in the UK!

My observations on the North alignment process are a bit puzzling so I thought I'd share them:

- The scope aligns very carefully (and consistently, wherever I place it) 10 degrees East of North (declination is 2 degrees here so I'm not particularly worried about which North)

- It then looks for (typically) Rigel, and slews to about 10 degrees East of Rigel.

- It says it can't find it, but will have another go.

- It then slews about 10 degrees West, and finds it with no problem (usually).

It would be fantastic to understand a bit more about how the software works, and I may be reading too much into this but... Is this a sort of last-ditch fix for a badly aligned magnetic sensor, whereby the scope tries a correction based on earlier, successful, manual alignments?

Any views welcome, folks.

#7 ChrisHall

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Posted 20 February 2013 - 03:43 AM

Oops - you can tell I'm a newbie - thought I'd lost the first version of the above post and so did it again. Apologies.

#8 REC

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Posted 20 February 2013 - 10:02 AM

Just an FYI...right now from my location, it finds the first star, which I don't remember and the second star is Rigel and that's where it stops. I don't usually pay close attention as it is aligning it's self, just that what ever the stars are, make sure I can see them over head. I just know it is Rigel as when I first start observing I start with the last star that is in the EP to adjust the focusing. Noticed Rigel was a double star:)

Bob

#9 astrogeoguy

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Posted 20 February 2013 - 06:20 PM

You might also check that your time zone is correct and that DAylight Savings is being handled properly. This will shift the entire sky an hours worth. You can check your scope's time/date on the handbox by hitting Mode and then scrolling down the various values RA, Dec, etc. The Time Zone settings are under the Preferences menu.

#10 Christopher Erickson

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Posted 21 February 2013 - 01:14 PM

:help:An open plea to Meade's Lightswitch engineers. :help:

Last night I took my LS-8 out to a public outreach event in a parking lot in Richmond Hill, ON. The sky was beautifully clear and dark in all directions.

I set up my LS-8 about 20 feet from the last row of cars and powered it up. It performed flawlessly until the North alignment step.

The scope swung around to north, stopped, made the small motions to pinpoint magnetic north, then adjusted itself for true north. I stood behind it and watched it carefully aligns itself a good TEN DEGREES off Polaris, which I could easily see above me! After that, the 2-star alignment failed to find Sirius, then Rigel! I eventuially carried out a manual 2-star alignment with huge azimuth shifts required to center each one.

Normally, the scope works beautifully, but this incorrect north fix is a major flaw in the process, and occurs at home and at public events.

Please, I beg you, give us a new firmware revision with the ability to accept or adjust the find north determination! It's a few lines of code! It only needs to give me 20 seconds to decide before it proceeds automatically.

I love this scope! This fix would, I'm quite sure, make these scopes far more reliable for suburban users, and result in far fewer RMAs from frustrated owners.

I look forward to your response. Thanks in advance.


Is there a "Calibrate Sensors", "Calibrate on Home" or any other Calibrate functions in the hand controller's setup?

Magnetic North calibration might help, if there is a way to do it.

And cars and other large metal objects can throw off detection of correct magnetic North.

I hope this helps.

#11 Christopher Erickson

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Posted 21 February 2013 - 01:17 PM

Hmm. I would never thought that Meade uses North alignment in this "full-auto" LS series. I believed that North alignment is an obsolete feature of first-generation GoTo systems. Personally, I had the same unpleasant experience with small ETX-80. After using Nexstar SE (which doesn't require pointing North or tube leveling) it was kinda new to me to use a compass,and check local magnetic deviation before observing session. And, after all these tricks, the scope veered away from proposed alignment star for at least 8 deg. And so on. I hate North align!

Now it's pretty interesting to compare these two full-auto Goto's from Meade (LS) and Celestron (SkyProdigy). They may (or may not) have different logic of self-alignment.
Clear skies,

Serge


Yes, even these "full auto" scopes need to somehow find True North in order to work. The tiny alignment camera has a narrow field of view.

This is one of those times where Celestron's "Pick any three bright stars" method really can work a lot better.

#12 Christopher Erickson

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Posted 21 February 2013 - 01:19 PM

I personally think that Meade's determination of local magnetic North is highly accurate. It's that local sources of magnetic interference (including some steel elements on tripods, vehicles, etc.) perturb the local magnetic North direction.

Walk around your property with a compass and see for yourself. I just want to be able to correct for that.

Chris


Setting up near power lines can really disrupt Magnetic North detection too.

#13 astrogeoguy

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Posted 21 February 2013 - 11:01 PM

No - the LS scopes use Autostar III and only have centre finder (calibrates the camera), and training the alt and az drives. No options for the other types of calibrations you mentioned above.

#14 Christopher Erickson

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Posted 22 February 2013 - 12:06 AM

No - the LS scopes use Autostar III and only have centre finder (calibrates the camera), and training the alt and az drives. No options for the other types of calibrations you mentioned above.


Bummer!!!

#15 ChrisHall

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Posted 24 February 2013 - 05:50 AM

Many thanks - interesting idea (and all ideas welcomed!) I tried it - I tried fixing the time zone (it defaults to 'auto') but sadly no difference. Next I will reload the firmware completely (as soon as I can get hold of one of those obscure mini SD cards) and try that. Then sadly it's back to the shop...

#16 ChrisHall

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Posted 28 March 2013 - 07:52 AM

Many thanks - interesting idea (and all ideas welcomed!) I tried it - I tried fixing the time zone (it defaults to 'auto') but sadly no difference. Next I will reload the firmware completely (as soon as I can get hold of one of those obscure mini SD cards) and try that. Then sadly it's back to the shop...


And just to finish this rather sad tale... It was back to the shop with the ls8. Unknown repair timescale, and no more ls8s available in the uk, so all money refunded and I got a Celestron cpc8 instead. Much simpler and I very much hope there's less to go wrong! Also, I have to say, it's about ten times more robust, and very, very much more stable - no focusing vibration. Recommended.






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