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Q. about Sirius EQ-G

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#1 DaveE

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Posted 01 April 2011 - 07:56 AM

Hi all, I've searched the manuals but can't find a clear answer to this question:

Once I perform a polar alignment and star alignment and begin searching for things, what if I want to increase accuracy? For example, in my Intelliscope dob, I can point to any object and "add alignment object" and the Intelliscope will add this star/object/whatever to the alignment process, increasing the accuracy. Point it to Deneb, add alignment star #4. Point it to Sirius, add alignment star #5. Etc. etc... the more, the merrier...

Is this possible in the Sirius mount? I can't seem to find any function that lets me do this:
1. Polar align
2. 1/2/3-star alignment
3. Slew to a star
---these are the important steps below:
4. Use the hand controller to tweak the object perfectly in the center of the EP
5. Press a function to use this as an additional alignment star, thereby increasing accuracy (hopefully)

Thanks,
-Dave

#2 rmollise

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Posted 01 April 2011 - 08:43 AM

Hi all, I've searched the manuals but can't find a clear answer to this question:

Once I perform a polar alignment and star alignment and begin searching for things, what if I want to increase accuracy? For example, in my Intelliscope dob, I can point to any object and "add alignment object" and the Intelliscope will add this star/object/whatever to the alignment process, increasing the accuracy. Point it to Deneb, add alignment star #4. Point it to Sirius, add alignment star #5. Etc. etc... the more, the merrier...

Is this possible in the Sirius mount? I can't seem to find any function that lets me do this:
1. Polar align
2. 1/2/3-star alignment
3. Slew to a star
---these are the important steps below:
4. Use the hand controller to tweak the object perfectly in the center of the EP
5. Press a function to use this as an additional alignment star, thereby increasing accuracy (hopefully)

Thanks,
-Dave


You mean "sync"? If that is what you are talking about, hit the manual again and look for P.A.E, "pointing accuracy enhancement."

If you mean mapping more alignment stars, you would have to go to EQMOD.

Actually, the best way to increase go-to accuracy is to choose alignment stars carefully. Don't just pick the first two the controller displays. Pick to that are well separated in azimuth and, importantly, two or three hours apart in _R.A._.

#3 DaveE

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Posted 01 April 2011 - 09:05 AM

Thanks --
I've read about PAE and it appears to be a one-time configuration utility that allows you to enhance the tracking accuracy of the mount in general.

What I'm looking for is a tool that lets you use the star you're currently observing as a new alignment star, further "teaching" the scope beyond what it knew when you first aligned three stars two hours ago. The Intelliscope controller lets you do this so I was hoping this controller did too.

So you're saying in order to do this (you called it "mapping more alignments stars") then I would have to grab a laptop and use EQMOD in the field?

-Dave

#4 stevethatsmyname

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Posted 01 April 2011 - 01:15 PM

Thanks --
I've read about PAE and it appears to be a one-time configuration utility that allows you to enhance the tracking accuracy of the mount in general.

What I'm looking for is a tool that lets you use the star you're currently observing as a new alignment star, further "teaching" the scope beyond what it knew when you first aligned three stars two hours ago. The Intelliscope controller lets you do this so I was hoping this controller did too.

So you're saying in order to do this (you called it "mapping more alignments stars") then I would have to grab a laptop and use EQMOD in the field?

-Dave


I believe this is correct. My friend has an Atlas (same software as Sirius) and he can only do 3 stars at a time. Not certain what the reason for this is, but personally I speculate that the software on the Sirius/Atlas is older than the intelliscope software. Not sure though.

If you wish to add a new star it must replace an old star.

EQMod will do as many stars as you want. I think there's even an article somewhere about the mathematics that EQmod uses.

#5 Phil Sherman

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Posted 01 April 2011 - 02:22 PM

PAE improves the pointing accuracy around the star you use for the PAE function. If you move to another area of the sky; pick a new (local to where you're pointing) star and redo the PAE. Every time you do this; the controller remaps the sky using the latest PAE location as an "I'm definitely located here" point. Unfortunately, it can only do this for one point.

EQMOD, on the other hand, uses a different pointing mechanism. A simple description is: every time you do a sync, it maps the current celestial coordinates to an altitude and azimuth and saves the latter set with the motor positions corresponding to it. The altitude and azimuth, relative to the mount, never change. When EQMOD does a goto; it maps the RA and DEC, using the current time, to altitude and azimuth to figure out which sync points it has will work best to point the mount. The overall pointing accuracy is limited only by how accurately the mount returns to the same position when the stepper motor counts return to the same value that they were at when the sync was done. This is normally very very accurate.

Phil

#6 rmollise

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Posted 01 April 2011 - 03:38 PM

Thanks --
I've read about PAE and it appears to be a one-time configuration utility that allows you to enhance the tracking accuracy of the mount in general.

What I'm looking for is a tool that lets you use the star you're currently observing as a new alignment star, further "teaching" the scope beyond what it knew when you first aligned three stars two hours ago. The Intelliscope controller lets you do this so I was hoping this controller did too.

So you're saying in order to do this (you called it "mapping more alignments stars") then I would have to grab a laptop and use EQMOD in the field?

-Dave


No. PAE is very similar to sync. It allows you to temporarily improve pointing in one area.

What you are after is REPLACING an alignment star. That is not possible with the SynScan firmware.

EQMOD from a laptop will allow you to use many stars.

As I said, though, a careful alignment is the best way to go.

#7 DaveE

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Posted 01 April 2011 - 06:09 PM

Thanks --
To be clear, I wish to ADD additional alignment stars during the night, not replace.

Dave

#8 rmollise

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Posted 02 April 2011 - 09:15 AM

Thanks --
To be clear, I wish to ADD additional alignment stars during the night, not replace.

Dave


OK...well, you can't. Not with the hand control. EQMOD only.

If you've got a good alignment initially, it should NOT be necessary to add any stars for good pointing performance.






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