Date   

Re: #APCC - V1.9 Tracking Error #APCC

Bill Long
 

I can send you and export of the points I use if you want them.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Rouz <rbidshahri@...>
Sent: Saturday, August 28, 2021 5:45 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error
 
Ok Ray, I won't change that variable at this point. Lets see how it performs with the previous PE curve as Roland suggsted.


-Rouz


Re: #APCC - V1.9 Tracking Error #APCC

Rouz
 

Ok Ray, I won't change that variable at this point. Lets see how it performs with the previous PE curve as Roland suggsted.


-Rouz


Re: GTO vs AE/AEL data #Absolute_Encoders

ap@CaptivePhotons.com
 

@Roger M wrote:

  • I’m looking for solid data of GTO vs AE/AEL. In other words, at what scale and at what seeing quality do you see an improvement with the absolute encoders vs. a fully guided setup?_._,_._,_

Roger and I corresponded a bit off line as well, and I am curious as well.

The MyT was much better than the CEM70G (even with their revised RA/DEC controller boards), but absolutely I can say that so far my results with the AP1100 are much more consistent than the MyT.  But… is that the heavier, better engineered mount or the encoders (or both, which is my guess).

My main motivation in choosing the encoders was a hope that in the dry season here, which also comes with a bit more wind at night, I would have more ability to image despite the sail I have on my tripod (otherwise known as a C11 with dew shield).  Previously, both CEM70G and MyT, it did not take much wind at all to show up as all sorts of eccentricity issues.  Gusts would show a spiderweb of protrusions from a star; steadier wind would just be ovals.

So my logic (aka rationalization) was I’d rather end up regretting spending extra money not needed than finding my new fancy AP mount did not really improve my wind performance.

I’ve had very few nights out so far, and exactly one of them started with some wind that quickly died down; nothing learned.  Perversely summer here, when everyone would love a breeze, often has nights with 100% humidity and no wind.

To date I have no idea, in calm winds, if I would see any difference (guided) with encoders off and on.  My GUESS is no difference in star visible shape, not sure if measurable.  I base that on endless reports how good non-encoder AP mounts are.  

But when the wind picks up a bit, it will all be worth it if I get another 3-4mph tolerance.  We do not have MUCH wind most winter nights, just too much for the non-encoder mounts that came before. 3-4mph might double the usable nights I get, easily.

So ask me again when (if) I ever get some time with clear nights.

(And yes, observatories, wind shields, all sort of discussions could be had here – but HOA rules and nightly teardowns limit what I can do, let’s please not go there for now).

Linwood


Re: APCC move axis question

Andy Ermolli
 

I think I figured out what was causing my issues with move axis. I had tracking correction turned on in APCC, that seemed to conflict with the direction arrows in NINA.
Once I turned it off the direction arrows worked consistently as expected. The easy fix is to turn off tracking correction during the automated 3 point polar align with NINA and then turn it back on after it's done!


Re: GTO vs AE/AEL data #Absolute_Encoders

RogerM
 

Hi Roland:

Linwood’s data compares a CEM70 vs the 1100AE. I would argue that an AP mount, be a 900GTO or 1100AE should show an improvement in FWHM m/eccentricity over a CEM. 

I’m looking for solid data of GTO vs AE/AEL. In other words, at what scale and at what seeing quality do you see an improvement with the absolute encoders vs. a fully guided setup?

Thanks, Roger M


Re: GTO vs AE/AEL data #Absolute_Encoders

Roland Christen
 


I was hoping for concrete data
Linwood's chart showed concrete data of star sizes. What kind of data are you looking for?

Roland


-----Original Message-----
From: RogerM <rogezeus2003@...>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 5:13 pm
Subject: Re: [ap-gto] GTO vs AE/AEL data #Absolute_Encoders

Hi Roland:

Thanks for your reply. I was hoping for concrete data but up to now, nobody has had much of a data set or even a good comparison. I will keep fishing :)

--
Roland Christen
Astro-Physics


Re: GTO vs AE/AEL data #Absolute_Encoders

RogerM
 

Hi Roland:

Thanks for your reply. I was hoping for concrete data but up to now, nobody has had much of a data set or even a good comparison. I will keep fishing :)


Re: ISS Tracked using APCC Pro v1.9

jimmyjujames
 

 
I'm hoping to get a camera with a higher frame rate to do stacking of different parts of ISS pass.
 
The ISS in not the same as a DSO
 
On approach you are recording the front.
When overhead you are recording the bottom of ISS
When departing you are recording the rear of ISS.

By the time I acquire the ISS, it's above the trees, 30+ degrees and already has visible rotation.
 
Our Earth would become a black hole if compressed down to a radius of 9mm (11/32 inch)
 smaller than 1 cubic inch (about 1/2 teaspoon).
Our Big Bang may NOT have originated at the center but from the outside
 beyond 13.7 billion light-years analogous to a Supernova generating a Black Hole.
 The predicted Schwarzschild radius for our observable universe is 13.7 billion light-years.
 Are we living in a black hole?
 Are we living in a universe within a black hole within another universe? That would be a lot of rooms.
 


Re: Adjusting cone error with camera and no view of pole?

Tom Blahovici
 

All of these are good. I do plan on using a model so maybe this is all moot.
Thanks, Tom


Re: #APCC - V1.9 Tracking Error #APCC

Ray Gralak
 

Also, I suspect even though my points are very close, the model isn't big enough. What is the recommended
spacing between points for Ra and Dec, 2 to 3 degrees apart?

I'm not sure what people use, Ray would have to chime in on that.
It depends on the accuracy of the plate-solves and pointing repeatability of the setup, so you will have to experiment to determine the minimum number of points you need. Any randomness in the system will affect overall tracking accuracy, both when capturing sky data points and tracking with a model. Usually more data points will help.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Roland Christen via groups.io
Sent: Saturday, August 28, 2021 1:56 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error


Also, I suspect even though my points are very close, the model isn't big enough. What is the recommended
spacing between points for Ra and Dec, 2 to 3 degrees apart?

I'm not sure what people use, Ray would have to chime in on that.


Rolando



-----Original Message-----
From: Rouz <rbidshahri@gmail.com>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 3:32 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error


Roland,

Got it.
Just uploaded the previous curve, and then read it again from the mount. Looks identical to the previous screenshot.
I'll double check with a PHD run as you stated.



"These two things are measured completely differently. Guiding error is normally presented as an rms number,
whereas PE is usually given as a P-P number. The two are not equivalent. You can have 5 arc sec P-P in a guiding
run and have the rms measurement be less than 1 arc sec."
Yes the PHD is rms, P-P is higher. Hopefully unguided without encoders can match guiding just as well.




Also, I suspect even though my points are very close, the model isn't big enough. What is the recommended
spacing between points for Ra and Dec, 2 to 3 degrees apart?

Thanks,
-Rouz

--
Roland Christen
Astro-Physics


Re: #APCC - V1.9 Tracking Error #APCC

Roland Christen
 

One thing I discovered last night while testing a new setup was that I got inconsistent pointing after modeling. I traced it down to a focuser drawtube that was not snugged down and locked into place. So, as the scope slewed around the sky to get the points, the camera was shifting slightly with gravity. It amounted to about 5 arc sec over a 4 hour RA swing. I tightened the focuser down and the error went away.

Rolando

-----Original Message-----
From: Roland Christen via groups.io <chris1011@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Sat, Aug 28, 2021 3:56 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error


Also, I suspect even though my points are very close, the model isn't big enough. What is the recommended spacing between points for Ra and Dec, 2 to 3 degrees apart?
I'm not sure what people use, Ray would have to chime in on that.

Rolando


-----Original Message-----
From: Rouz <rbidshahri@...>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 3:32 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error

Roland,

Got it.
Just uploaded the previous curve, and then read it again from the mount. Looks identical to the previous screenshot. I'll double check with a PHD run as you stated.



"These two things are measured completely differently. Guiding error is normally presented as an rms number, whereas PE is usually given as a P-P number. The two are not equivalent. You can have 5 arc sec P-P in a guiding run and have the rms measurement be less than 1 arc sec."
Yes the PHD is rms, P-P is higher. Hopefully unguided without encoders can match guiding just as well.




Also, I suspect even though my points are very close, the model isn't big enough. 
What is the recommended spacing between points for Ra and Dec, 2 to 3 degrees apart?

Thanks,
-Rouz

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Re: #APCC - V1.9 Tracking Error #APCC

Roland Christen
 


Also, I suspect even though my points are very close, the model isn't big enough. What is the recommended spacing between points for Ra and Dec, 2 to 3 degrees apart?
I'm not sure what people use, Ray would have to chime in on that.

Rolando


-----Original Message-----
From: Rouz <rbidshahri@...>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 3:32 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error

Roland,

Got it.
Just uploaded the previous curve, and then read it again from the mount. Looks identical to the previous screenshot. I'll double check with a PHD run as you stated.



"These two things are measured completely differently. Guiding error is normally presented as an rms number, whereas PE is usually given as a P-P number. The two are not equivalent. You can have 5 arc sec P-P in a guiding run and have the rms measurement be less than 1 arc sec."
Yes the PHD is rms, P-P is higher. Hopefully unguided without encoders can match guiding just as well.




Also, I suspect even though my points are very close, the model isn't big enough. 
What is the recommended spacing between points for Ra and Dec, 2 to 3 degrees apart?

Thanks,
-Rouz

--
Roland Christen
Astro-Physics


Re: #APCC - V1.9 Tracking Error #APCC

Rouz
 

Roland,

Got it.
Just uploaded the previous curve, and then read it again from the mount. Looks identical to the previous screenshot. I'll double check with a PHD run as you stated.



"These two things are measured completely differently. Guiding error is normally presented as an rms number, whereas PE is usually given as a P-P number. The two are not equivalent. You can have 5 arc sec P-P in a guiding run and have the rms measurement be less than 1 arc sec."
Yes the PHD is rms, P-P is higher. Hopefully unguided without encoders can match guiding just as well.




Also, I suspect even though my points are very close, the model isn't big enough. 
What is the recommended spacing between points for Ra and Dec, 2 to 3 degrees apart?

Thanks,
-Rouz


Re: Mach2 Problem with RS232 Connections.

Stacey Mills
 

Even though I'm fine with things working as they do now, I love a mystery, so I swapped out the RocketPort card for a spare that I had....same result.  Tried swapping the cables as well, and updating/repairing the drivers.  I'm sure the boards were seated well.  Strangely, they work in test/null modem mode.  First time I've ever had an issue with these cards but this is the only PCIe one that I have used.  Too hot to fool with it any more today.  I'm satisfied it has something to do with Windows10, the drivers or the motherboard, but my alternate solution with the 4-port USB->serial works fine so that's enough for now.  At least I know not to throw away the RocketPort cards!

-Stacey


Re: #APCC - V1.9 Tracking Error #APCC

Roland Christen
 


This mount has no encoders and a good PEC will reduce the PE to say 1 arcsecond.

My typical OAG guiding error was a very consistent 0.4 arcseconds.
These two things are measured completely differently. Guiding error is normally presented as an rms number, whereas PE is usually given as a P-P number. The two are not equivalent. You can have 5 arc sec P-P in a guiding run and have the rms measurement be less than 1 arc sec.

Roland

-----Original Message-----
From: Rouz <rbidshahri@...>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 2:14 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error

A general question:

This mount has no encoders and a good PEC will reduce the PE to say 1 arcsecond.

My typical OAG guiding error was a very consistent 0.4 arcseconds.

Would be correct to say that even with a good PE curve and modeling, the OAG would still yield better guiding?


--
Roland Christen
Astro-Physics


Re: #APCC - V1.9 Tracking Error #APCC

Roland Christen
 


I will reload that previous PE curve you said was good and will turn PEM on and make another model.
Before you make any model, be sure that your PE curve is actually working correctly. That means running PHD again with PEM ON, and noting the resultant unguided curve (ignore the drift). If it doesn't look like the original one, then it was loaded wrong.

Roland


-----Original Message-----
From: Rouz <rbidshahri@...>
To: main@ap-gto.groups.io
Sent: Sat, Aug 28, 2021 2:10 pm
Subject: Re: [ap-gto] #APCC - V1.9 Tracking Error

Roland,

Thank you for clarifying that.

Yes, I understood that PE correction applies to the few arcseconds of sinusoidal like wiggle in the Ra. Dec drift, should be corrected by the model.


I didn't see how a few arcseconds of wiggle would drift the image continuously, but given the drift disappeared after I made a new model with PEM off, I assumed that corrupt curve was messing up the model numbers as it was an accumulation of miscalculations with each slew perhaps.


So next,
I will reload that previous PE curve you said was good and will turn PEM on and make another model.



-Rouz

--
Roland Christen
Astro-Physics


Re: Mach2 Problem with RS232 Connections.

Christopher Erickson
 

I have seen RocketPort card problems in the past and they usually were traced to the card not being fully seated in the PC's card slot.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Sat, Aug 28, 2021 at 7:45 AM Ray Gralak <iogroups@...> wrote:
Stacey,

That's great news! I am glad it was something you can correct without having to send in your CP5!

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Stacey Mills
> Sent: Saturday, August 28, 2021 9:46 AM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 Problem with RS232 Connections.
>
> Hi Ray,  I've got the problem solved.  I went back out into the HOT observatory and the USB->serial connection to
> the CP5 worked!  I'm not sure what the issue was earlier.  I again tested my RocketPort card with a null modem
> between two card ports and a couple of terminal programs (TeraTerm) and it seemed to work fine.  However, I
> figured I'd pull out a separate USB->4 serial port adapter that I had and see if that would work, AND IT DID, on both
> CP5 RS232 ports.  So the problem lies with my RocketPort card and not the CP5.  I'm not sure why the terminal
> programs worked and the CP5 didn't but I won't pursue that at the moment.  Since the serial ports are backups to
> the ethernet anyway, I'm happy using that setup and I'll yank the RocketPort card for now.  So sorry to have caused
> an issue that was really on my end.  Thanks!
>
> -Stacey
>







Re: Adjusting cone error with camera and no view of pole?

Christopher Erickson
 

First, if you are using APCC-Pro, modelling compensates for cone error so you don't have to shim or adjust anything. It's all taken care of via APCC software in the model.

Second, I prefer adjusting cone error during the day. Too hard for me to go from a dim eyepiece to a flashlight and tools and bolts and shims and back to the dim eyepiece. I pick a distant terrestrial object near straight East or West on the horizon, turn off tracking and flip back and forth over the meridian on that object, taking into consideration the parallax distance as I flip back and forth. And I use the sides of pop cans cut with scissors and a paper punch for shims. I shim between the dovetail bar and the OTA rings or radius blocks.

And make sure your OTA is very carefully collimated before evaluating or adjusting the cone error. No big deal on refractors but a big deal on reflectors.

Cone error, a.k.a. orthogonality a.k.a. perpendicularity, is the relationship between the DEC axis and the optical axis, not the OTA axis.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Sat, Aug 28, 2021 at 8:11 AM Tom Blahovici <tom.va2fsq@...> wrote:
Hi
How does one adjust cone error if you have no view of the pole and use a camera?
Thanks


Re: ISS Tracked using APCC Pro v1.9

Robert Berta
 

Brent...nice job. Is that a video in a format like AVI that can be entered into Autostakkert? If so Autostakkert would pick best shots, perfectly align, and stack into a higher resolution single image. That is what I use for Ha solar astronomy. It is amazing how what seems to be a so-so not sharp image in a video becomes amazingly detailed and sharp.


Re: #APCC - V1.9 Tracking Error #APCC

Rouz
 

A general question:

This mount has no encoders and a good PEC will reduce the PE to say 1 arcsecond.

My typical OAG guiding error was a very consistent 0.4 arcseconds.

Would be correct to say that even with a good PE curve and modeling, the OAG would still yield better guiding?

2761 - 2780 of 83216