Very frustrated with my model. Errors seem very large. #Mach2GTO #Polar_Alignment


Micheal Fields Jr
 

Used the QHY Polemax camera and software to dial in the polar alignment which seemed pretty straight forward.  Should be right on the money.

Then I also happen to have the MGbox and that is connected providing temp, pressure, humidity and GPS.

I am running a piece of software on my computer called Dimension4 which communicates with all the atomic clocks all over the world and gets extremely precise time.  I have the software choose to update time from PC as "recommended".

So the polar alignment should be excellent, the time offset correction should be excellent, the gps coordinates excellent, the weather information pretty good.

Using SGP I did a focus run prior to doing the model.

Now some details that are going against me.
The telecope is an 11" EdgeHD.  I am using two dovetail bars. Both Losmandy D type with radius blocks. One on top of the scope and one of course on the bottom.  The bolts are very tight FYI.
I have the easy balance 16" saddle and it is also bolted very tightly to the mount.  I double checked all bolts.

Clutches are tight, the two side knobs on the mount for elevation clutch are both tight.  The three bolts from the adapter pier plate are tight as are the bolts from that plate to the top of the tripod.

But it is an SCT.  And I am focusing using the primary mirror which means it is not locked and does move around under its own weight.

The imaging train is light weight and is all threaded connections.  Nothing moves.

So I start the model and it shows me results like RA delta is -2948.643 and the dec delta is -1581.175 arc min.

When complete and I look at the "model" it shows things like 9599.37 arc-seconds East Model and 9548.46 arc-seconds in West model.  Polar axis elecation 143987.03 east and 139238.67 west.  Index Error HA 230742.67 east and -225292.62 west.

What does that mean?   Well I assume it means that what it wants to see and what it actually sees are very different. 

I wonder if I am not checking the correct boxes.

Then when I am done I am seeing, based upon those high numbers, a very high number for the polar alignment error.  But I know it is correctly aligned.

Then when I am all done with the bad model and I have tracking adjustments enabled and the model enabled a 5 second image is all star trails.

So obviously everything is wrong as if it thinks the time is something it isn't or the GPS coordinates are something they are not or it is just plate solving the wrong position? 

I tried it with SGP and both Platesolve2 and ASTAP.  Both yield the same issue.

Now If I just do a regular T-Point run in TSX Pro with all model stuff disabled, it seems normal and reasonable.  Since the mirror is unlocked because I focus using the primary mirror so I need to model any mirror shift/flop, The sky RMS pointing in TSX Pro after doing a 33 point run and crunching it with a "super model" is 16.6  PSD=19.15 

So my "point" hehe is that TSX T-Point doesn't seem to have any issues with dramatic errors in pointing. 

So I am stumped.   Why am I seeing such chaos?

If I am just throwing out a random guess that would make sense to me would be that it is not reading/understanding the gps coordinates and elevation correctly so when it solves an image it is drastically off from where it thinks it should be.  But with a GPS connected, the MGbox, and the time synced with my PC, AND absolute encoders, this should not ever happen.

Thoughts?


Seb@stro
 

Hello Michael,

Have you checked that the time zones and DST settings are correct (i.e. all the same or all set to UTC) in your PC clock, softwares, mount/keypad ?

I have the software choose to update time from PC as "recommended".
I personally don’t use SGP, SkyX, MGBox nor APPC (yet) so can’t really help specifically about those but my general recommendation regarding time settings of whatever systems would be to use only ONE source be it a NTP server (internet), gps, precision oscillator (local clock), etc. for all the components that need to interact together. Because two time sources (no matter how accurate they are) will always have some drift to one another to some degree.

So assuming your time settings are harmonized (TZ, DST or UTC) maybe try setting only the internet time source for everything (if that’s possible) so you can rule-out that possibility.

Might seems obvious but if you haven’t already also make sure that the gps is correctly reporting time to your softwares to rule out any communication or configuration (message format) issue and assess it has acquired enough satellites of sufficient signal strength for the duration of the modelling run.

Hope that helps.

Clear skies!
Sébastien


Peter Bresler
 

I had a HD1100 which I unloaded because of limited back focus. My first advice would be to use a guide scope and Sharpcap Pro to polar align the mount. Polemax is a waste of money. My polar alignment on my 1200 is right on, and easily checked and corrected. You can use an OAG on the HD1100 without either a focuser OR an EFW. SGP will give highly accurate gotos and centering. Be sure the scale settings and pixel settings for the camera you are using are correct.


Peter Nagy
 

SharpCap Pro works very well with PoleMaster (not PoleMax??).

Peter 


Andrea Lucchetti
 

I can confirm this, polemaster works.
I had issues at the beginning but later I’ve found out that I need to tight the ADATRI TRIPOD KNOBS with an hex key.

But I don’t think it is the case here if you had success with tpoint


 

one small thing

>>>I am running a piece of software on my computer called Dimension4 

i have been told not to use this piece of software, as the small continuous time adjustments may cause issues

On Thu, Jan 7, 2021 at 3:15 AM Micheal Fields Jr via groups.io <mpfjr=yahoo.com@groups.io> wrote:
Used the QHY Polemax camera and software to dial in the polar alignment which seemed pretty straight forward.  Should be right on the money.

Then I also happen to have the MGbox and that is connected providing temp, pressure, humidity and GPS.

I am running a piece of software on my computer called Dimension4 which communicates with all the atomic clocks all over the world and gets extremely precise time.  I have the software choose to update time from PC as "recommended".

So the polar alignment should be excellent, the time offset correction should be excellent, the gps coordinates excellent, the weather information pretty good.

Using SGP I did a focus run prior to doing the model.

Now some details that are going against me.
The telecope is an 11" EdgeHD.  I am using two dovetail bars. Both Losmandy D type with radius blocks. One on top of the scope and one of course on the bottom.  The bolts are very tight FYI.
I have the easy balance 16" saddle and it is also bolted very tightly to the mount.  I double checked all bolts.

Clutches are tight, the two side knobs on the mount for elevation clutch are both tight.  The three bolts from the adapter pier plate are tight as are the bolts from that plate to the top of the tripod.

But it is an SCT.  And I am focusing using the primary mirror which means it is not locked and does move around under its own weight.

The imaging train is light weight and is all threaded connections.  Nothing moves.

So I start the model and it shows me results like RA delta is -2948.643 and the dec delta is -1581.175 arc min.

When complete and I look at the "model" it shows things like 9599.37 arc-seconds East Model and 9548.46 arc-seconds in West model.  Polar axis elecation 143987.03 east and 139238.67 west.  Index Error HA 230742.67 east and -225292.62 west.

What does that mean?   Well I assume it means that what it wants to see and what it actually sees are very different. 

I wonder if I am not checking the correct boxes.

Then when I am done I am seeing, based upon those high numbers, a very high number for the polar alignment error.  But I know it is correctly aligned.

Then when I am all done with the bad model and I have tracking adjustments enabled and the model enabled a 5 second image is all star trails.

So obviously everything is wrong as if it thinks the time is something it isn't or the GPS coordinates are something they are not or it is just plate solving the wrong position? 

I tried it with SGP and both Platesolve2 and ASTAP.  Both yield the same issue.

Now If I just do a regular T-Point run in TSX Pro with all model stuff disabled, it seems normal and reasonable.  Since the mirror is unlocked because I focus using the primary mirror so I need to model any mirror shift/flop, The sky RMS pointing in TSX Pro after doing a 33 point run and crunching it with a "super model" is 16.6  PSD=19.15 

So my "point" hehe is that TSX T-Point doesn't seem to have any issues with dramatic errors in pointing. 

So I am stumped.   Why am I seeing such chaos?

If I am just throwing out a random guess that would make sense to me would be that it is not reading/understanding the gps coordinates and elevation correctly so when it solves an image it is drastically off from where it thinks it should be.  But with a GPS connected, the MGbox, and the time synced with my PC, AND absolute encoders, this should not ever happen.

Thoughts?



--
Brian 



Brian Valente


Ray Gralak
 

Hi Michael,

Although you don't specifically mention APCC, I assume that is what you are using for a model?

If so, the behavior you are describing sounds like you may be running the ASCOM Platform 6.5 with the "Transform" bug. APPM and APCC use the ASCOM Transform class to convert plate-solved J2000 coordinates to the current epoch. The severe bug in this version of ASCOM makes the Transform class un-reusable, so all follow-up J2000 transformations return the same RA,Dec coordinate pair as the first, and thus results a bad model.

I suggest you download and install ASCOM Platform 6.5 SP1 from the ASCOM web site. Unfortunately you will have to use APPM to collect data points again.

https://www.ascom-standards.org

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Micheal Fields Jr via groups.io
Sent: Thursday, January 7, 2021 3:15 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Very frustrated with my model. Errors seem very large. #Mach2GTO #Polar_Alignment

Used the QHY Polemax camera and software to dial in the polar alignment which seemed pretty straight forward.
Should be right on the money.

Then I also happen to have the MGbox and that is connected providing temp, pressure, humidity and GPS.

I am running a piece of software on my computer called Dimension4 which communicates with all the atomic
clocks all over the world and gets extremely precise time. I have the software choose to update time from PC as
"recommended".

So the polar alignment should be excellent, the time offset correction should be excellent, the gps coordinates
excellent, the weather information pretty good.

Using SGP I did a focus run prior to doing the model.

Now some details that are going against me.
The telecope is an 11" EdgeHD. I am using two dovetail bars. Both Losmandy D type with radius blocks. One on
top of the scope and one of course on the bottom. The bolts are very tight FYI.
I have the easy balance 16" saddle and it is also bolted very tightly to the mount. I double checked all bolts.

Clutches are tight, the two side knobs on the mount for elevation clutch are both tight. The three bolts from the
adapter pier plate are tight as are the bolts from that plate to the top of the tripod.

But it is an SCT. And I am focusing using the primary mirror which means it is not locked and does move around
under its own weight.

The imaging train is light weight and is all threaded connections. Nothing moves.

So I start the model and it shows me results like RA delta is -2948.643 and the dec delta is -1581.175 arc min.

When complete and I look at the "model" it shows things like 9599.37 arc-seconds East Model and 9548.46 arc-
seconds in West model. Polar axis elecation 143987.03 east and 139238.67 west. Index Error HA 230742.67
east and -225292.62 west.

What does that mean? Well I assume it means that what it wants to see and what it actually sees are very
different.

I wonder if I am not checking the correct boxes.

Then when I am done I am seeing, based upon those high numbers, a very high number for the polar alignment
error. But I know it is correctly aligned.

Then when I am all done with the bad model and I have tracking adjustments enabled and the model enabled a 5
second image is all star trails.

So obviously everything is wrong as if it thinks the time is something it isn't or the GPS coordinates are
something they are not or it is just plate solving the wrong position?

I tried it with SGP and both Platesolve2 and ASTAP. Both yield the same issue.

Now If I just do a regular T-Point run in TSX Pro with all model stuff disabled, it seems normal and reasonable.
Since the mirror is unlocked because I focus using the primary mirror so I need to model any mirror shift/flop, The
sky RMS pointing in TSX Pro after doing a 33 point run and crunching it with a "super model" is 16.6 PSD=19.15

So my "point" hehe is that TSX T-Point doesn't seem to have any issues with dramatic errors in pointing.

So I am stumped. Why am I seeing such chaos?

If I am just throwing out a random guess that would make sense to me would be that it is not
reading/understanding the gps coordinates and elevation correctly so when it solves an image it is drastically off
from where it thinks it should be. But with a GPS connected, the MGbox, and the time synced with my PC, AND
absolute encoders, this should not ever happen.

Thoughts?


Mike Dodd
 

On 1/7/2021 10:18 AM, Brian Valente wrote:
one small thing

>>>I am running a piece of software on my computer called Dimension4

i have been told not to use this piece of software, as the small
continuous time adjustments may cause issues
I use Dimension4 to sync my observatory PC's clock. No issues at all. I have it configured to sync when when it launches as the PC starts up, then every 30 or 60 minutes (don't remember which).

Note that these syncs are not"continuous." Plus after the initial bootup sync, any adjustments are tiny.

HTH.

--- Mike
http:// astronomy.mdodd.com


Micheal Fields Jr
 

Yes Ray, I am using APCC.  Can I use something else to model?  Your question seems to imply I can?  If so, can you or someone else please explain that process?  Or do you mean use the hand controller to manually align?

I am nearly 100% positive I have the latest ascom SP1.  Not only do I keep it up to date but I also did a "check for updates" from the ascom folder and it reported no new updates available.  What I can try is to uninstall it clean and do a fresh install.  I keep a portable hard drive with all the latest revisions of all my drivers and software but when I am too lazy to find it I typically just do a re-download.   I also captured some video of these issues but it is hours long and needs to be edited down to something worth a watch.  Was up until 4am fighting with this so the 4 hours of sleep I am on now means I may not get anything accomplished today.


On Thu, Jan 7, 2021 at 07:29 AM, Ray Gralak wrote:
Hi Michael,

Although you don't specifically mention APCC, I assume that is what you are using for a model?

If so, the behavior you are describing sounds like you may be running the ASCOM Platform 6.5 with the "Transform" bug. APPM and APCC use the ASCOM Transform class to convert plate-solved J2000 coordinates to the current epoch. The severe bug in this version of ASCOM makes the Transform class un-reusable, so all follow-up J2000 transformations return the same RA,Dec coordinate pair as the first, and thus results a bad model.

I suggest you download and install ASCOM Platform 6.5 SP1 from the ASCOM web site. Unfortunately you will have to use APPM to collect data points again.

https://www.ascom-standards.org

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Micheal Fields Jr via groups.io
Sent: Thursday, January 7, 2021 3:15 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Very frustrated with my model. Errors seem very large. #Mach2GTO #Polar_Alignment

Used the QHY Polemax camera and software to dial in the polar alignment which seemed pretty straight forward.
Should be right on the money.

Then I also happen to have the MGbox and that is connected providing temp, pressure, humidity and GPS.

I am running a piece of software on my computer called Dimension4 which communicates with all the atomic
clocks all over the world and gets extremely precise time. I have the software choose to update time from PC as
"recommended".

So the polar alignment should be excellent, the time offset correction should be excellent, the gps coordinates
excellent, the weather information pretty good.

Using SGP I did a focus run prior to doing the model.

Now some details that are going against me.
The telecope is an 11" EdgeHD. I am using two dovetail bars. Both Losmandy D type with radius blocks. One on
top of the scope and one of course on the bottom. The bolts are very tight FYI.
I have the easy balance 16" saddle and it is also bolted very tightly to the mount. I double checked all bolts.

Clutches are tight, the two side knobs on the mount for elevation clutch are both tight. The three bolts from the
adapter pier plate are tight as are the bolts from that plate to the top of the tripod.

But it is an SCT. And I am focusing using the primary mirror which means it is not locked and does move around
under its own weight.

The imaging train is light weight and is all threaded connections. Nothing moves.

So I start the model and it shows me results like RA delta is -2948.643 and the dec delta is -1581.175 arc min.

When complete and I look at the "model" it shows things like 9599.37 arc-seconds East Model and 9548.46 arc-
seconds in West model. Polar axis elecation 143987.03 east and 139238.67 west. Index Error HA 230742.67
east and -225292.62 west.

What does that mean? Well I assume it means that what it wants to see and what it actually sees are very
different.

I wonder if I am not checking the correct boxes.

Then when I am done I am seeing, based upon those high numbers, a very high number for the polar alignment
error. But I know it is correctly aligned.

Then when I am all done with the bad model and I have tracking adjustments enabled and the model enabled a 5
second image is all star trails.

So obviously everything is wrong as if it thinks the time is something it isn't or the GPS coordinates are
something they are not or it is just plate solving the wrong position?

I tried it with SGP and both Platesolve2 and ASTAP. Both yield the same issue.

Now If I just do a regular T-Point run in TSX Pro with all model stuff disabled, it seems normal and reasonable.
Since the mirror is unlocked because I focus using the primary mirror so I need to model any mirror shift/flop, The
sky RMS pointing in TSX Pro after doing a 33 point run and crunching it with a "super model" is 16.6 PSD=19.15

So my "point" hehe is that TSX T-Point doesn't seem to have any issues with dramatic errors in pointing.

So I am stumped. Why am I seeing such chaos?

If I am just throwing out a random guess that would make sense to me would be that it is not
reading/understanding the gps coordinates and elevation correctly so when it solves an image it is drastically off
from where it thinks it should be. But with a GPS connected, the MGbox, and the time synced with my PC, AND
absolute encoders, this should not ever happen.

Thoughts?


Micheal Fields Jr
 

On Thu, Jan 7, 2021 at 06:54 AM, Peter Nagy wrote:
SharpCap Pro works very well with PoleMaster (not PoleMax??).

Peter 
Sorry I said the wrong word.  I have the QHY PoleMaster camera/software.  Even if it was garbage it would still be within an arc-minute.  The results I get show it is dramatically out.  Also when I do a T-Point run, filter with super model, and then check the polar alignment it is not anywhere near as bad as reported by the AP Point Mapper.  I just wish it were obvious what the issue is.  I like Ray's idea that it is a bad ASCOM version.  Would be easy to fix. 


 

When I ran into a similar issue on our ap1600 i found my location and date/time data was incorrect. 


On Thu, Jan 7, 2021 at 9:15 AM Micheal Fields Jr via groups.io <mpfjr=yahoo.com@groups.io> wrote:
On Thu, Jan 7, 2021 at 06:54 AM, Peter Nagy wrote:
SharpCap Pro works very well with PoleMaster (not PoleMax??).

Peter 
Sorry I said the wrong word.  I have the QHY PoleMaster camera/software.  Even if it was garbage it would still be within an arc-minute.  The results I get show it is dramatically out.  Also when I do a T-Point run, filter with super model, and then check the polar alignment it is not anywhere near as bad as reported by the AP Point Mapper.  I just wish it were obvious what the issue is.  I like Ray's idea that it is a bad ASCOM version.  Would be easy to fix. 



--
Brian 



Brian Valente


Micheal Fields Jr
 

On Thu, Jan 7, 2021 at 06:27 AM, Seb@stro wrote:
Hello Michael,

Have you checked that the time zones and DST settings are correct (i.e. all the same or all set to UTC) in your PC clock, softwares, mount/keypad ?

I have the software choose to update time from PC as "recommended".
I personally don’t use SGP, SkyX, MGBox nor APPC (yet) so can’t really help specifically about those but my general recommendation regarding time settings of whatever systems would be to use only ONE source be it a NTP server (internet), gps, precision oscillator (local clock), etc. for all the components that need to interact together. Because two time sources (no matter how accurate they are) will always have some drift to one another to some degree.

So assuming your time settings are harmonized (TZ, DST or UTC) maybe try setting only the internet time source for everything (if that’s possible) so you can rule-out that possibility.

Might seems obvious but if you haven’t already also make sure that the gps is correctly reporting time to your softwares to rule out any communication or configuration (message format) issue and assess it has acquired enough satellites of sufficient signal strength for the duration of the modelling run.

Hope that helps.

Clear skies!
Sébastien
Yes, this is what I was thinking.  If the GPS or Time is very far off that would explain it.  The solve point and the assumed point would be dramatically different and result in a big error.  But unless I am simply overlooking something obvious, I don't see evidence of that.  I will for sure double check.


Micheal Fields Jr
 

On Thu, Jan 7, 2021 at 06:28 AM, Peter Bresler wrote:
I had a HD1100 which I unloaded because of limited back focus. My first advice would be to use a guide scope and Sharpcap Pro to polar align the mount. Polemax is a waste of money. My polar alignment on my 1200 is right on, and easily checked and corrected. You can use an OAG on the HD1100 without either a focuser OR an EFW. SGP will give highly accurate gotos and centering. Be sure the scale settings and pixel settings for the camera you are using are correct.
Back focus issues are an issue for sure.  That is why I am focusing with the primary mirror.   Seems to be fine in that respect.  I have zero interest in getting a guide scope simply to do a polar align. That is why I bought PoleMaster.  Polemax I actually don't know what that is but I was super tired last night(see my post time) and wasn't thinking clearly enough to remember the correct name.  PoleMaster is pretty straight forward and works a lot like Sharpcap.  In fact I think I might be able to use SharpCap with the PoleMaster camera?  Not sure but that would be fun to try.  Regardless  there will be some error because the PoleMaster is connected to the RA axis of the mount at the pivot point and the telescope will naturally have, unless shimmed, some orthogonality errors.  A pointing model will detect those.   And yes, pixel scale and all that is correct.  I did  a plate solve and entered in the pixel scale and position angle of the camera both in SGP and in TSX.


Micheal Fields Jr
 

On Thu, Jan 7, 2021 at 06:54 AM, Peter Nagy wrote:
SharpCap Pro works very well with PoleMaster (not PoleMax??).

Peter 
Yah I goofed.  I mean PoleMaster from QHY.  I just bought it from OPT and it was delivered yesterday in time for me to use it to align last night.  Worked pretty good.


Ray Gralak
 

Hi Michael,

Yes Ray, I am using APCC. Can I use something else to model? Your question seems to imply I can? If so, can
you or someone else please explain that process? Or do you mean use the hand controller to manually align?
There are a few choices in pointing models, like TPoint, MaxPoint, APCC Pro, and the new hand controller firmware in conjunction with the Mach 2 firmware. Only APCC Pro and the hand controller firmware perform tracking rate modeling, but the main issue you mentioned concerned pointing, so I wanted to be sure you were talking about APCC.

Just to re-iterate, what described sounds like the ASCOM bug, but there is always a possibility it is something else. If you want, you can either post or email your APPM log files and PNT files. It would be best to zip them with APCC's "Log Zipper" utility that can be started from APCC's tools menu. If you choose to use email, my email is at groups3 AT gralak dot com.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Micheal Fields Jr via groups.io
Sent: Thursday, January 7, 2021 9:07 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Very frustrated with my model. Errors seem very large. #Mach2GTO #Polar_Alignment

Yes Ray, I am using APCC. Can I use something else to model? Your question seems to imply I can? If so, can
you or someone else please explain that process? Or do you mean use the hand controller to manually align?

I am nearly 100% positive I have the latest ascom SP1. Not only do I keep it up to date but I also did a "check for
updates" from the ascom folder and it reported no new updates available. What I can try is to uninstall it clean
and do a fresh install. I keep a portable hard drive with all the latest revisions of all my drivers and software but
when I am too lazy to find it I typically just do a re-download. I also captured some video of these issues but it is
hours long and needs to be edited down to something worth a watch. Was up until 4am fighting with this so the 4
hours of sleep I am on now means I may not get anything accomplished today.

On Thu, Jan 7, 2021 at 07:29 AM, Ray Gralak wrote:


Hi Michael,

Although you don't specifically mention APCC, I assume that is what you are using for a model?

If so, the behavior you are describing sounds like you may be running the ASCOM Platform 6.5 with the
"Transform" bug. APPM and APCC use the ASCOM Transform class to convert plate-solved J2000 coordinates
to the current epoch. The severe bug in this version of ASCOM makes the Transform class un-reusable, so all
follow-up J2000 transformations return the same RA,Dec coordinate pair as the first, and thus results a bad
model.

I suggest you download and install ASCOM Platform 6.5 SP1 from the ASCOM web site. Unfortunately
you will have to use APPM to collect data points again.

https://www.ascom-standards.org

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver




-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Micheal Fields Jr via
groups.io
Sent: Thursday, January 7, 2021 3:15 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Very frustrated with my model. Errors seem very large. #Mach2GTO
#Polar_Alignment

Used the QHY Polemax camera and software to dial in the polar alignment which seemed pretty
straight forward.
Should be right on the money.

Then I also happen to have the MGbox and that is connected providing temp, pressure, humidity
and GPS.

I am running a piece of software on my computer called Dimension4 which communicates with all
the atomic
clocks all over the world and gets extremely precise time. I have the software choose to update time
from PC as
"recommended".

So the polar alignment should be excellent, the time offset correction should be excellent, the gps
coordinates
excellent, the weather information pretty good.

Using SGP I did a focus run prior to doing the model.

Now some details that are going against me.
The telecope is an 11" EdgeHD. I am using two dovetail bars. Both Losmandy D type with radius
blocks. One on
top of the scope and one of course on the bottom. The bolts are very tight FYI.
I have the easy balance 16" saddle and it is also bolted very tightly to the mount. I double checked
all bolts.

Clutches are tight, the two side knobs on the mount for elevation clutch are both tight. The three
bolts from the
adapter pier plate are tight as are the bolts from that plate to the top of the tripod.

But it is an SCT. And I am focusing using the primary mirror which means it is not locked and does
move around
under its own weight.

The imaging train is light weight and is all threaded connections. Nothing moves.

So I start the model and it shows me results like RA delta is -2948.643 and the dec delta is -
1581.175 arc min.

When complete and I look at the "model" it shows things like 9599.37 arc-seconds East Model and
9548.46 arc-
seconds in West model. Polar axis elecation 143987.03 east and 139238.67 west. Index Error HA
230742.67
east and -225292.62 west.

What does that mean? Well I assume it means that what it wants to see and what it actually sees
are very
different.

I wonder if I am not checking the correct boxes.

Then when I am done I am seeing, based upon those high numbers, a very high number for the
polar alignment
error. But I know it is correctly aligned.

Then when I am all done with the bad model and I have tracking adjustments enabled and the
model enabled a 5
second image is all star trails.

So obviously everything is wrong as if it thinks the time is something it isn't or the GPS coordinates
are
something they are not or it is just plate solving the wrong position?

I tried it with SGP and both Platesolve2 and ASTAP. Both yield the same issue.

Now If I just do a regular T-Point run in TSX Pro with all model stuff disabled, it seems normal and
reasonable.
Since the mirror is unlocked because I focus using the primary mirror so I need to model any mirror
shift/flop, The
sky RMS pointing in TSX Pro after doing a 33 point run and crunching it with a "super model" is 16.6
PSD=19.15

So my "point" hehe is that TSX T-Point doesn't seem to have any issues with dramatic errors in
pointing.

So I am stumped. Why am I seeing such chaos?

If I am just throwing out a random guess that would make sense to me would be that it is not
reading/understanding the gps coordinates and elevation correctly so when it solves an image it is
drastically off
from where it thinks it should be. But with a GPS connected, the MGbox, and the time synced with
my PC, AND
absolute encoders, this should not ever happen.

Thoughts?


Khushrow Machhi
 

Hi Michael,
I just added the encoders on my 1100GTO and when I built a model my pointing was also way off. After reading the manual I figured I needed to do a plate solve and recal. This is also done in APPM and after I did this one time, then building models and pointing was accurate. 
Khushrow


Peter Nagy
 

I find SharpCap Pro much easier to use than PoleMaster software. It doesn't matter whether PoleMaster is orthogonal or not as long as you can see the stars surrounding Polaris. SharpCap Pro uses true plate solving unlike PoleMaster software. SharpCap Pro is not free and it's an annual subscription that costs only 10 euro and it's worth it.

Peter 


Joseph Beyer
 

Just curious, how long does it take to polar align using SharpCap Pro with the PoleMaster camera versus the PoleMaster camera using its native software?    


Peter Nagy
 

Speed isn't an issue because the time difference between both software is not much but with experience, I would say SharpCap Pro might be faster. First time using the software would be longer because you need to use the right gain and offset and other settings which is a one time adjustment and it remembers all settings from then on. You also need to wait till about 30 to 45 minutes before total darkness to be able to see enough stars to get accurate polar alignment. I never timed it myself but I would say up to 5 minutes to get polar aligned with SharpCap Pro. 

Peter 


deonb
 

SharpCap Pro is easier to work with initially. When it works...

Unfortunately, if you have long Focal Lengths's or less than perfect sky conditions it will fail. I've never had it work on a 2800mm FL with a ASI183MM even in perfect sky conditions. Also, vignetting will cause it to fail every time.  On the best of days it works maybe 50% of the time on my long FL cameras.  NINA+ASTAP can resolve those same plates with 99% accuracy - same day/same equipment. Sharpcap doesn't take the Focal Length into account anywhere when doing plate solves, which causes its undoing.

The PoleMaster however, because it's done by hand, pretty much always works. Overcast moonlit night with fast moving clouds over polaris with the observatory shutter obscuring half of the view? Meh, it doesn't care. 

If you're used to both systems, and use the same equipment for alignment every time, the PoleMaster process will also be faster. Eventually. There is a long step to determine the axis center on both where you have to rotate the scope around the RA axis 90 degrees. SharpCap does this every time. Polemaster can save this information and re-use it. So once you can skip this step and re-use the saved information, the Polemaster alignment becomes quicker overall. There are a few stupid unnecessary steps that they do (like asking multiple times for the 5-star identification). I wish their software was better written. But once you get to know it and expect this, it's fast to use.

"Does match success?". Yes. Yes, match success...