APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO


Andrea Lucchetti
 

Hello,
I'd need some help to understand the model results (Dec arc) of my Mach2.
From the results and point data it seems that the Hour angle offset error on the west side is much bigger than that on the est side.
The error is visible in the different points on the west side, that are really off and in a consistent way.
Non perpendicularity errors also show the same behavior but we discussed that they are not significant for a dec arc model.

So, my two questions:
-what can be the source for this error?
-can this error, that seems to affect all the points on the west side cause a drift in RA? I don't know how an RA tracking rate adjustment is calculated from the pointing data.

Different model in different nights exhibit the same characteristics.
Applying them and enabling tracking corrections does improve Dec tracking but produce a drift in RA.
Actually in DEC drift goes to zero  over several hours ( a clear improvement over an already  good polar alignment)

-the telescope is a newtonian, 200mm f4 
-the set up is "nomad"
-longitude is checked 
-environment data were approximate but "good enough" (temperature was 15 instead of 20 used in the model)
-I usually polar align with NINA or polemaster, then launch a Dec arc model of three arcs (1 Deg separation), about 30 points in total
-I still guide with PHD bacause of the drift in RA

At the link you can find: 

https://www.dropbox.com/t/o0IjqEn2hsTerLrY

The APPC log, the Appm model, point data, and PHD log.

I have a couple of weeks before new moon and I hope to get new ideas and try them next time.
Thanks a lot,
Andrea


 

Andrea would you mind also posting a screen capture of the model window?

I just want to see what you're seeing without overwriting my model with yours, at least not yet ;)

On Fri, Nov 11, 2022 at 2:13 PM Andrea Lucchetti <andlucchett@...> wrote:
Hello,
I'd need some help to understand the model results (Dec arc) of my Mach2.
From the results and point data it seems that the Hour angle offset error on the west side is much bigger than that on the est side.
The error is visible in the different points on the west side, that are really off and in a consistent way.
Non perpendicularity errors also show the same behavior but we discussed that they are not significant for a dec arc model.

So, my two questions:
-what can be the source for this error?
-can this error, that seems to affect all the points on the west side cause a drift in RA? I don't know how an RA tracking rate adjustment is calculated from the pointing data.

Different model in different nights exhibit the same characteristics.
Applying them and enabling tracking corrections does improve Dec tracking but produce a drift in RA.
Actually in DEC drift goes to zero  over several hours ( a clear improvement over an already  good polar alignment)

-the telescope is a newtonian, 200mm f4 
-the set up is "nomad"
-longitude is checked 
-environment data were approximate but "good enough" (temperature was 15 instead of 20 used in the model)
-I usually polar align with NINA or polemaster, then launch a Dec arc model of three arcs (1 Deg separation), about 30 points in total
-I still guide with PHD bacause of the drift in RA

At the link you can find: 

https://www.dropbox.com/t/o0IjqEn2hsTerLrY

The APPC log, the Appm model, point data, and PHD log.

I have a couple of weeks before new moon and I hope to get new ideas and try them next time.
Thanks a lot,
Andrea




 

PS - i did not see a .pnt file in your dropbox?


On Fri, Nov 11, 2022 at 2:13 PM Andrea Lucchetti <andlucchett@...> wrote:
Hello,
I'd need some help to understand the model results (Dec arc) of my Mach2.
From the results and point data it seems that the Hour angle offset error on the west side is much bigger than that on the est side.
The error is visible in the different points on the west side, that are really off and in a consistent way.
Non perpendicularity errors also show the same behavior but we discussed that they are not significant for a dec arc model.

So, my two questions:
-what can be the source for this error?
-can this error, that seems to affect all the points on the west side cause a drift in RA? I don't know how an RA tracking rate adjustment is calculated from the pointing data.

Different model in different nights exhibit the same characteristics.
Applying them and enabling tracking corrections does improve Dec tracking but produce a drift in RA.
Actually in DEC drift goes to zero  over several hours ( a clear improvement over an already  good polar alignment)

-the telescope is a newtonian, 200mm f4 
-the set up is "nomad"
-longitude is checked 
-environment data were approximate but "good enough" (temperature was 15 instead of 20 used in the model)
-I usually polar align with NINA or polemaster, then launch a Dec arc model of three arcs (1 Deg separation), about 30 points in total
-I still guide with PHD bacause of the drift in RA

At the link you can find: 

https://www.dropbox.com/t/o0IjqEn2hsTerLrY

The APPC log, the Appm model, point data, and PHD log.

I have a couple of weeks before new moon and I hope to get new ideas and try them next time.
Thanks a lot,
Andrea




Andrea Lucchetti
 

Hi Brian,
please try again with this link:

I've added the pnt file and the screenshot.
thanks a lot for your help
Andrea


Il giorno ven 11 nov 2022 alle ore 23:17 Brian Valente <bvalente@...> ha scritto:
PS - i did not see a .pnt file in your dropbox?

On Fri, Nov 11, 2022 at 2:13 PM Andrea Lucchetti <andlucchett@...> wrote:
Hello,
I'd need some help to understand the model results (Dec arc) of my Mach2.
From the results and point data it seems that the Hour angle offset error on the west side is much bigger than that on the est side.
The error is visible in the different points on the west side, that are really off and in a consistent way.
Non perpendicularity errors also show the same behavior but we discussed that they are not significant for a dec arc model.

So, my two questions:
-what can be the source for this error?
-can this error, that seems to affect all the points on the west side cause a drift in RA? I don't know how an RA tracking rate adjustment is calculated from the pointing data.

Different model in different nights exhibit the same characteristics.
Applying them and enabling tracking corrections does improve Dec tracking but produce a drift in RA.
Actually in DEC drift goes to zero  over several hours ( a clear improvement over an already  good polar alignment)

-the telescope is a newtonian, 200mm f4 
-the set up is "nomad"
-longitude is checked 
-environment data were approximate but "good enough" (temperature was 15 instead of 20 used in the model)
-I usually polar align with NINA or polemaster, then launch a Dec arc model of three arcs (1 Deg separation), about 30 points in total
-I still guide with PHD bacause of the drift in RA

At the link you can find: 

https://www.dropbox.com/t/o0IjqEn2hsTerLrY

The APPC log, the Appm model, point data, and PHD log.

I have a couple of weeks before new moon and I hope to get new ideas and try them next time.
Thanks a lot,
Andrea



--


Chris White
 

My model runs always show very minimal error on the east side and significantly more error on the west side. 

I have had superb unguided performance with eccentricity generally in the 0.28 to 0.4 range, so I don't think there is any problems with this. Others I have spoken to have seen the same thing. 

I dont know why it happens, buy its not been a problem in my case. 


Andrea Lucchetti
 

thank you.
I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.

I was wandering if the model results could explain it.
from the guiding plot it seems the RA is always "below the line" (slow?).
Even with guiding on my eccentricity is about 0.54 


Ray Gralak
 

Hi Andrea,

thank you.
I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.

I was wandering if the model results could explain it.
from the guiding plot it seems the RA is always "below the line" (slow?).
Even with guiding on my eccentricity is about 0.54
After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray


Andrea Lucchetti
 

Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray







 

Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray









Andrea Lucchetti
 

It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--


 

I don't think a newt would have mirror shift that would explain what you're seeing.

LIke others, my western mapping results tend to be "worse" than the eastern side

it could be more attributable to flexure, though I don't know for sure

On Mon, Nov 14, 2022 at 8:28 AM Andrea Lucchetti <andlucchett@...> wrote:
It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--




Bill Long
 

My experience is the same. The delta values are higher in the West 



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brian Valente <bvalente@...>
Sent: Monday, November 14, 2022 8:34 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
I don't think a newt would have mirror shift that would explain what you're seeing.

LIke others, my western mapping results tend to be "worse" than the eastern side

it could be more attributable to flexure, though I don't know for sure

On Mon, Nov 14, 2022 at 8:28 AM Andrea Lucchetti <andlucchett@...> wrote:
It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--



--


Andrea Lucchetti
 

Well, I don’t know really: the telescope is really sturdy, mirror support seems the only potential reason. I think I can improve it, I don’t know how to improve the remaining. I am  designing a new mirror cell that should be overkill for such a small mirror, let’s see what happen.
Still, I don’t understand if these errors are correlated to the RA drift that I See.
I understand many observe higher errors on the west side but with good tracking

Il giorno lun 14 nov 2022 alle 17:34 Brian Valente <bvalente@...> ha scritto:
I don't think a newt would have mirror shift that would explain what you're seeing.

LIke others, my western mapping results tend to be "worse" than the eastern side

it could be more attributable to flexure, though I don't know for sure

On Mon, Nov 14, 2022 at 8:28 AM Andrea Lucchetti <andlucchett@...> wrote:
It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--



--


Andrea Lucchetti
 

Thanks.
Tracking performance is the same on both sides or you see differences between est and west? Thanks

Il giorno lun 14 nov 2022 alle 20:34 Bill Long <bill@...> ha scritto:
My experience is the same. The delta values are higher in the West 



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brian Valente <bvalente@...>
Sent: Monday, November 14, 2022 8:34 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
I don't think a newt would have mirror shift that would explain what you're seeing.

LIke others, my western mapping results tend to be "worse" than the eastern side

it could be more attributable to flexure, though I don't know for sure

On Mon, Nov 14, 2022 at 8:28 AM Andrea Lucchetti <andlucchett@...> wrote:
It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--



--


Chris White
 
Edited

Andrea,

Keep in mind that guiding itself is a potential source of error. 

With my telescopes I actually get better performance unguided than I do with guiding. 130gtx and epsilon 160. 

I build my models with dec spacing at 1 to 2 degrees and RA at 7 degrees. I might tweak this, but it only takes about 20 to 25 min to complete a run. 

Give unguided a try. You might be surprised. I sure was!


Bill Long
 

I've not noticed a change in performance at all.



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Andrea Lucchetti <andlucchett@...>
Sent: Monday, November 14, 2022 2:25 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
Thanks.
Tracking performance is the same on both sides or you see differences between est and west? Thanks

Il giorno lun 14 nov 2022 alle 20:34 Bill Long <bill@...> ha scritto:
My experience is the same. The delta values are higher in the West 



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brian Valente <bvalente@...>
Sent: Monday, November 14, 2022 8:34 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
I don't think a newt would have mirror shift that would explain what you're seeing.

LIke others, my western mapping results tend to be "worse" than the eastern side

it could be more attributable to flexure, though I don't know for sure

On Mon, Nov 14, 2022 at 8:28 AM Andrea Lucchetti <andlucchett@...> wrote:
It is a Newtonian. The mirror has a minimal clearance to avoid astigmatism.
It is small enough that collimation is not affected. But it is not a refractor

Il giorno lun 14 nov 2022 alle 17:04 Brian Valente <bvalente@...> ha scritto:
Hi Andrea

>>>My hypothesis was mirror flop.

are you using a telescope that has mirror flop?

On Mon, Nov 14, 2022 at 8:01 AM Andrea Lucchetti <andlucchett@...> wrote:
Thank you Ray.
I can increase settling time.
For the number of points, it is a nomad setup so I need to optimize the set up time. May be I can also play with the number of arcs? I though 3 were the minimum but if there is a trade off between arcs and number of points I could play with that.

For settling, I think it can be the case at the flip but the points are acquired on the same pier side and they all show the deviation. After the first point it should be less impacting.
My hypothesis was mirror flop.
But my question is: can these deviations be modeled such as the adjusted RA rate  is not right?
Ad I said, in DEC the model seems to give wonderful result’s.
Thank you for looking into my data
Andrea

Il giorno lun 14 nov 2022 alle 15:47 Ray Gralak <iogroups@...> ha scritto:
Hi Andrea,

> thank you.
> I'd like to try unguided but I think I need to solve the RA drift first, this is my issue.
>
> I was wandering if the model results could explain it.
> from the guiding plot it seems the RA is always "below the line" (slow?).
> Even with guiding on my eccentricity is about 0.54

After a pier flip there may be some settling occurring in the telescope. If that happens the data may not be as accurate.

Also, I noticed from the PNT file that the spacing is pretty large between the points. Using more points (e.g. every 3-5 degrees) will not only improve tracking accuracy, but also give your mount more time to settle on the West side after the pier flip.

-Ray








--



--


Bill Long
 

My experience has largely been the same, that unguided imaging with a model will improve the quality of my data over guided imaging -- with the caveat that the models are of course important to use. 

I have been using models of about 55 points, configured like you see below: 



The time estimate is fairly accurate. It runs in about 25 mins, which is close enough. 🙂 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Chris White <chris.white@...>
Sent: Monday, November 14, 2022 3:22 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 

[Edited Message Follows]

Andrea,

Keep in mind that guiding itself is a potential source of error. 

With my telescopes I actually get better performance unguided than I do with guiding. 130gtx and epsilon 160. 

I build my models with dec spacing at 1 to 2 degrees and RA at 7 degrees. I might tweak this, but it only takes about 20 to 25 min to complete a run. 

Give unguided a try. You might be surprised. I sure was!


 

Bill i also like that you set a high min altitude - I have a similar. why bother modeling an altitude i never image at

it also keeps the model fairly dense vs. a lower altitude

On Mon, Nov 14, 2022 at 7:37 PM Bill Long <bill@...> wrote:
My experience has largely been the same, that unguided imaging with a model will improve the quality of my data over guided imaging -- with the caveat that the models are of course important to use. 

I have been using models of about 55 points, configured like you see below: 



The time estimate is fairly accurate. It runs in about 25 mins, which is close enough. 🙂 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Chris White <chris.white@...>
Sent: Monday, November 14, 2022 3:22 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 

[Edited Message Follows]

Andrea,

Keep in mind that guiding itself is a potential source of error. 

With my telescopes I actually get better performance unguided than I do with guiding. 130gtx and epsilon 160. 

I build my models with dec spacing at 1 to 2 degrees and RA at 7 degrees. I might tweak this, but it only takes about 20 to 25 min to complete a run. 

Give unguided a try. You might be surprised. I sure was!




Bill Long
 

For sure, Brian.

I have a serious tree problem here and have to image at very high altitudes as a result. For an example of just how bad it is, I am working on a project of the Heart Nebula + HB3 Supernova Remnant, largely based on Chris' great image. Currently the object is very high in the sky at 64 degrees, and I have no issues imaging it. In fact, at the start of the night it was 47 degrees and still quite good for me. Once it traverses the meridian however, it moves toward the west, and at about 2:10am Pacific it will creep into the trees, even at 60 degrees of altitude at that time. 

If anyone needs some fresh Alder, I have some you can come chop down and take for free. 🙂 

-Bill 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brian Valente <bvalente@...>
Sent: Monday, November 14, 2022 8:23 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
Bill i also like that you set a high min altitude - I have a similar. why bother modeling an altitude i never image at

it also keeps the model fairly dense vs. a lower altitude

On Mon, Nov 14, 2022 at 7:37 PM Bill Long <bill@...> wrote:
My experience has largely been the same, that unguided imaging with a model will improve the quality of my data over guided imaging -- with the caveat that the models are of course important to use. 

I have been using models of about 55 points, configured like you see below: 



The time estimate is fairly accurate. It runs in about 25 mins, which is close enough. 🙂 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Chris White <chris.white@...>
Sent: Monday, November 14, 2022 3:22 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 

[Edited Message Follows]

Andrea,

Keep in mind that guiding itself is a potential source of error. 

With my telescopes I actually get better performance unguided than I do with guiding. 130gtx and epsilon 160. 

I build my models with dec spacing at 1 to 2 degrees and RA at 7 degrees. I might tweak this, but it only takes about 20 to 25 min to complete a run. 

Give unguided a try. You might be surprised. I sure was!



--


Bill Long
 

Brian,

I should add that the model comes out pretty nicely:



From: Bill Long <bill@...>
Sent: Monday, November 14, 2022 8:31 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
For sure, Brian.

I have a serious tree problem here and have to image at very high altitudes as a result. For an example of just how bad it is, I am working on a project of the Heart Nebula + HB3 Supernova Remnant, largely based on Chris' great image. Currently the object is very high in the sky at 64 degrees, and I have no issues imaging it. In fact, at the start of the night it was 47 degrees and still quite good for me. Once it traverses the meridian however, it moves toward the west, and at about 2:10am Pacific it will creep into the trees, even at 60 degrees of altitude at that time. 

If anyone needs some fresh Alder, I have some you can come chop down and take for free. 🙂 

-Bill 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brian Valente <bvalente@...>
Sent: Monday, November 14, 2022 8:23 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 
Bill i also like that you set a high min altitude - I have a similar. why bother modeling an altitude i never image at

it also keeps the model fairly dense vs. a lower altitude

On Mon, Nov 14, 2022 at 7:37 PM Bill Long <bill@...> wrote:
My experience has largely been the same, that unguided imaging with a model will improve the quality of my data over guided imaging -- with the caveat that the models are of course important to use. 

I have been using models of about 55 points, configured like you see below: 



The time estimate is fairly accurate. It runs in about 25 mins, which is close enough. 🙂 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Chris White <chris.white@...>
Sent: Monday, November 14, 2022 3:22 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APPC & Mach2: Dec Arc model results and RA drift connection? #APCC #Mach2GTO
 

[Edited Message Follows]

Andrea,

Keep in mind that guiding itself is a potential source of error. 

With my telescopes I actually get better performance unguided than I do with guiding. 130gtx and epsilon 160. 

I build my models with dec spacing at 1 to 2 degrees and RA at 7 degrees. I might tweak this, but it only takes about 20 to 25 min to complete a run. 

Give unguided a try. You might be surprised. I sure was!



--