Looking for beta testers of new Polar Alignment utility.

[Gonzo]

Not a problem, please use them. Let me know if you need better pictures.

[themos]

Thanks!

[visionoz]

Hi Themos

Seen this app in iceinspace.com.au thus wanting to test it out in the SH and downloaded the version 1.0.3 and also Anaconda Python 2.7.x (initially the 64-bit verison & subsequently the 32-bit version) and after installation unfortunately my Windows 7 64-bit OS "refused" to allow me to associate PPA.py with python.exe (both 64-bit as well as the 32-bit version of Python) - I went through several installs & uninstalls but to no avail - "run as administrator" as well. Googled probable causes of why I cannot associate the .py file to a program to run and done several registry hacks as suggested and still no-go!!

Am at a loss as to what is causing my issue so will probably have to rebuild my astro PC back to basics and start afresh unless you can think of any reason why I cannot associate the PPA.py file to the python.exe program

TIA

Cheers

Bill

from Hot & Sunny Perth, DownUnder

[themos]

Hello Bill, what happens if you open an Anaconda Command Prompt from the Start menu and cd to the installation directory and issue "PPA.py" or "python PPA.py"? 

I just now managed to screw up the association deliberately! I have another python installation which is not loaded with the modules we need. To get back to something that works, I had to use the right-click "Open with" dialog and then "Choose default program..." then "Browse..." and then select the python.exe program from Anaconda's installation directory.

Edited January 5, 2015 by themos

[visionoz]

Hello Bill, what happens if you open an Anaconda Command Prompt from the Start menu and cd to the installation directory and issue "PPA.py" or "python PPA.py"? 

I just now managed to screw up the association deliberately! I have another python installation which is not loaded with the modules we need. To get back to something that works, I had to use the right-click "Open with" dialog and then "Choose default program..." then "Browse..." and then select the python.exe program from Anaconda's installation directory.

Hi Themos

Thanks for the reply - did already the right-mouse click "Open With" and even though I selected the python.exe file by browsing to it and ensuring that I selected it as the "default program" stubbornly it doesn't do it at all and I get back other installed programs in the list except Python!! Done a few other hacks as well as posted by others on the web but to no avail - methinks a "wipe & re-install" is required as I feel that the registry is corrupted somehow.

BTW this is what I get when I ran PPA.py in the command shell:

C:\Users\Ops\Documents\PhotoPolarAlign>python PPA.py

Traceback (most recent call last):

  File "PPA.py", line 1501, in <module>

    APP = PhotoPolarAlign(master=ROOT)

  File "PPA.py", line 1495, in __init__

    self.Sniff_AstroTortilla()

  File "PPA.py", line 1305, in Sniff_AstroTortilla

    lfn = os.listdir(dir)

WindowsError: [Error 3] The system cannot find the path specified: 'C\\Users\\Ops\\AppData\\Local\\astrotortilla.sf.net\\AstroTortilla/*.*'

C:\Users\Ops\Documents\PhotoPolarAlign>

HTH

Cheers

Bill

from Sunny & Extremely Hot Perth, DownUnder

[themos]

Ok, at least that's a mistake on my part, fixed in the development version. Please edit PPA.py and go to line 1495 and put a # at the beginning of the line so that the line becomes a comment.

[visionoz]

Thankyou mate - that's running now though I had to use command shell to run Python and PPA.py manually - I'll not worry about the file association issue at the moment since I can use PPA by writing a simple batch file to do it instead

Cheers

Bill

from Sunny & Extremely Hot Perth, DowUnder

[themos]

Hello again,

Version 1.0.4 is ready, Windows setup or Python file

Pathname blanks should be handled correctly,

dd:mm:ss display,

detects wrong parity (mirrors in optical train) and incompatible image dimensions,

local solver settings dialog,

local solver settings maintained in own settings file,

can import local solver settings from any AstroTortilla configuration file

Thanks for your support, everyone!

[themos]

Andy, thinking about it a bit more, I could find out which direction is the local horizontal if I know the location and the time and then adjust the instructions. Something to think about...

Well, astropy has facilities for determining the sidereal time so I can work out and mark the true vertical at the time the image is taken if I know the location (longitude, really) and the time of exposure in UTC. 

[AndyKeogh]

Hello again,

Version 1.0.4 is ready, Windows setup or Python file

Thanks for your support, everyone!

Downloaded and installed but due to clouds and rain  I have initially tested it with last night's solves and it produced the same answers    although the format of the move  has changed  .  Maybe I will grow to like it over time,  

In practise, I subtract the CP position from the RA axis position so use a measure of pixel change to work out how effective each move has been.

Thanks for all your efforts.

Andy

[Gonzo]

No apparent issues with the latest version on my Mac running Yosemite. Mind you, only tried Nova solve, need to go through the settings and add local.

[AndyKeogh]

Hi Themos  I wonder if you could clarify how you arrive at the move numbers?

Using the examples below  my CP error  is 6 pixels on the x axis and 2 pixels on the y axis ( I have ignore the limits due to rounding) and with a scale of 2.57"/pixel  this suggest my error is 15.42 arc seconds for the azimuth OR have I got this completely wrong ?

Andy

[themos]

Hello Andy, do you prefer decimal arcminutes? I could put an option in there... 

Regarding the discrepancy: I print round pixel numbers but the solver actually returns subpixel accuracy. I convert the decimal pixel distance into decimal degrees first and then split it up into degrees minutes and seconds (line 913 and 914).        

ddeg = abs(x2a - x1a)*the_scale/3600.0        inst = inst + ('%02d:%02d:%02d' % decdeg2dms(ddeg))

At the scale you are working on, half a pixel is more than 1 arcsecond so allowing for the actual pixel positions gaining or losing the odd arcsecond, we can reconcile the numbers. 

I see (4,2) as the pixel difference. Taking the square root of the sum of the squares = sqrt(20) = 4.472. Multiply by scale  = 11.493 arcsec = 0.192 arcmin. So the (4,2) was a rounding up of the true pixel error which is displayed (rounded ) as 0.18 arcmin. 

[visionoz]

Themos

Thanks for v1.0.4.

Want to ask some "silly" questions re: Local rather than online Nova use for obvious reasons; don't know whether if it is my fault/ignorance or whatever but what I'm experiencing at the moment with your included test images:

1) if I were to select "local" on either the "v" or "h" jpegs it takes a long time trying to solve but bombs out eventually. 

2) however if I were to solve only  "v" jpeg via Nova first and "h" jpeg by Local when the solve is completed only the "v" jpeg shows a computed data whilst "h" jpeg & "i" jpeg though showing "Solved" in green has no computed data showing in that field; the local solves takes only aro 3-6secs.

3) and if I were to then do a "Find Polar Axis" the computed data fields will be poplulated with data!

See attached screen shots. Also included is the settings page of PPA.

I have a feeling that my Astrotilla is not configured correctly and but am not too conversant with it though so any pointers would be greatly appreciated

TIA

Cheers

from Sunny Perth, DownUnder

[AndyKeogh]

Hi Themos  I wonder if you could clarify how you arrive at the move numbers?

Using the examples below  my CP error  is 6 pixels on the x axis and 2 pixels on the y axis ( I have ignore the limits due to rounding) and with a scale of 2.57"/pixel  this suggest my error is 15.42 arc seconds for the azimuth

OR have I got this completely wrong ?

Looks like mental arithmetic is no longer a strong point for me

Hello Andy, do you prefer decimal arcminutes? I could put an option in there... 

An option would be nice.  I have been analysing all my test runs since mid December and it looks like the altitude setting is critical to the amount of drift I am seeing over 10 hours  so I am trying to nail it at 0.000

Andy

[themos]

Hello, please trey again with downscale set to 2, scale_units set to arcsec/pix and limits set to 1 - 120. The extra options I use are  "-p -B none -M none -N none -R none -U none -S none". The provided images have a scale between 23 and 24 arcsec/pixel.

The numbers in the Computed column do not correspond to the data in the Given column. The displayed scale is the last scale computed from a solve. The pixel coordinates in the next 2 rows are computed after a "Find Polar Axis" or "Show Improvement" oepration and always refer to the Horizontal image and the Improved image respectively.

When you start using your own images, first solve  your first image in a fresh session with scale limits [1,120]. Once you know the scale of your imaging system, you can then adjust the the limits in the setting to speed up the local solve. If you check the "Restrict scale" button, scale limits are used for both Nova and local solves, if there exists a known scale (that is, if Computed scale is displayed). The limits are set to +-5% of the known scale. If no scale is known or "Restrict scale" is unchecked, then Nova solves are done without scale limits and local solves are done with whatever limits are specified in the Settings.

Edited January 8, 2015 by themos

[themos]

Looks like mental arithmetic is no longer a strong point for me

An option would be nice.  I have been analysing all my test runs since mid December and it looks like the altitude setting is critical to the amount of drift I am seeing over 10 hours  so I am trying to nail it at 0.000

Andy

Wow, Andy! How much do you trust the stability of your pier/tripod/bearings? I guess you'd first have to work out what the variation in drift is from one night to the next when you don't touch the polar alignment. I suspect you'd hit mechanical limits before you hit the precision limits of the PhotoPolarAlign method.

[visionoz]

Hello, please trey again with downscale set to 2, scale_units set to arcsec/pix and limits set to 1 - 120. The extra options I use are  "-p -B none -M none -N none -R none -U none -S none". The provided images have a scale between 23 and 24 arcsec/pixel.

The numbers in the Computed column do not correspond to the data in the Given column. The displayed scale is the last scale computed from a solve. The pixel coordinates in the next 2 rows are computed after a "Find Polar Axis" or "Show Improvement" oepration and always refer to the Horizontal image and the Improved image respectively.

When you start using your own images, first solve  your first image in a fresh session with scale limits [1,120]. Once you know the scale of your imaging system, you can then adjust the the limits in the setting to speed up the local solve. If you check the "Restrict scale" button, scale limits are used for both Nova and local solves, if there exists a known scale (that is, if Computed scale is displayed). The limits are set to +-5% of the known scale. If no scale is known or "Restrict scale" is unchecked, then Nova solves are done without scale limits and local solves are done with whatever limits are specified in the Settings.

WooHoo Themos!

That fixed the issue - so my Astrototlla was not fully configured correctly and that now works a treat!

Thanks for a very handy tool and I will give this app a shot when I go to my remote dark sky location in around coming new moon and report back here my experiences with it so that others can benefit from your efforts 

Cheers

Bill

from Sunny Perth, DownUnder

[AndyKeogh]

Wow, Andy! How much do you trust the stability of your pier/tripod/bearings? I guess you'd first have to work out what the variation in drift is from one night to the next when you don't touch the polar alignment. I suspect you'd hit mechanical limits before you hit the precision limits of the PhotoPolarAlign method.

What I am really trying to do is work out if a Skywatcher guide mount introduces flex or not.  What I have found is that if the "guidescope" is bolted into an M3 vixen clamp and the PA is 0 in altitude then I get about 12 arc seconds drift in RA & Dec over 10 hours  Due to other errors  my main imaging scope camera was not running  so I am still trying to characterise my mount.

Andy

[StuartJPP]

What I am really trying to do is work out if a Skywatcher guide mount introduces flex or not.  What I have found is that if the "guidescope" is bolted into an M3 vixen clamp and the PA is 0 in altitude then I get about 12 arc seconds drift in RA & Dec over 10 hours  Due to other errors  my main imaging scope camera was not running  so I am still trying to characterise my mount.

Andy

I think MetaGuide can calculate flexure between the imaging scope and the guide scope, not sure what configurations of imaging cameras are allowed though...with FlexRX it can allegedly compensate for it (to some degree)...but I haven't tried it.

[AndyKeogh]

I think MetaGuide can calculate flexure between the imaging scope and the guide scope, not sure what configurations of imaging cameras are allowed though...with FlexRX it can allegedly compensate for it (to some degree)...but I haven't tried it.

Thanks, I have downloaded it. Initial view is that it needs a video camera for guiding and I do not have one.

At this point in time I am trying to characterise the components on my mount and will worry about fixing issues later.

Andy

[AndyKeogh]

I have run into a problem trying to do a local solve   This was on a machine that had never had Anaconda installed before today.  First installation of PPA was 1.04  today.  Windows 7 64 bit

First of all I solved the image in Astrotortilla to be sure it should work.

Created a coarse and fine config as per instructions for V1.03

Imported that configuration into V1.04.

Image had been previously solved by Astrometry.net so the green solved button came up.  Ignored that and asked for a local solve  and this is what I got.....

C:\cygwin\bin\bash.exe --login -c "solve-field -b /etc/astrometry/backend.cfg -u
 degwidth -L 2.00 -H 4.50 -z 0 --sigma 70 --no-plots -N none -H 2 -L 4.5 -r --ob
js 100 -O  \"C:/Pictures/2015/2015_01_06/Polaralign/Q07A9354.JPG\""
Reading input file 1 of 1: "C:/Pictures/2015/2015_01_06/Polaralign/Q07A9354.JPG"
...
cygwin warning:
  MS-DOS style path detected: C:/Pictures/2015/2015_01_06/Polaralign/Q07A9354.JP
G
  Preferred POSIX equivalent is: /cygdrive/c/Pictures/2015/2015_01_06/Polaralign
/Q07A9354.JPG
  CYGWIN environment variable option "nodosfilewarning" turns off this warning.
  Consult the user's guide for more details about POSIX paths:
    http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
jpegtopnm: WRITING PPM FILE
Read file stdin: 5760 x 3840 pixels x 1 color(s); maxval 255
Using 8-bit output
Extracting sources...
simplexy: found 352 sources.
Solving...
Reading file "C:/Pictures/2015/2015_01_06/Polaralign/Q07A9354.axy"...
Scale range 2.8125 to 1.25 is invalid: min must be >= 0, max must be >= min.
backend-main.c:321:main: Failed to read job file "C:/Pictures/2015/2015_01_06/Po
laralign/Q07A9354.axy"
solve-field.c:518:run_backend backend failed.  Command that failed was:
  /usr/lib/astrometry/bin/backend --config /etc/astrometry/backend.cfg C:/Pictur
es/2015/2015_01_06/Polaralign/Q07A9354.axy
 ioutils.c:605:run_command_get_outputs Command failed: return value 255
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Anaconda\lib\lib-tk\Tkinter.py", line 1486, in __call__
    return self.func(*args)
  File "C:\Users\AKeogh\Documents\PhotoPolarAlign\PPA.py", line 1235, in <lambda
>
    nxt = Button(self.wfrop, text='Local', command=lambda : self.solve('v','loca
l'))
  File "C:\Users\AKeogh\Documents\PhotoPolarAlign\PPA.py", line 889, in solve
    limg2wcs(self, aimg, awcs, hint)
  File "C:\Users\AKeogh\Documents\PhotoPolarAlign\PPA.py", line 284, in limg2wcs

    self.update_scale(hint)
  File "C:\Users\AKeogh\Documents\PhotoPolarAlign\PPA.py", line 853, in update_s
cale
    self.scale = scale_frm_wcs(self.vwcs_fn)
  File "C:\Users\AKeogh\Documents\PhotoPolarAlign\PPA.py", line 520, in scale_fr
m_wcs
    hdu = fits.open(fn)
  File "C:\Anaconda\lib\site-packages\astropy\io\fits\hdu\hdulist.py", line 119,
 in fitsopen
    return HDUList.fromfile(name, mode, memmap, save_backup, **kwargs)
  File "C:\Anaconda\lib\site-packages\astropy\io\fits\hdu\hdulist.py", line 251,
 in fromfile
    save_backup=save_backup, **kwargs)
  File "C:\Anaconda\lib\site-packages\astropy\io\fits\hdu\hdulist.py", line 768,
 in _readfrom
    ffo = _File(fileobj, mode=mode, memmap=memmap)
  File "C:\Anaconda\lib\site-packages\astropy\io\fits\file.py", line 130, in __i
nit__
    raise IOError('File does not exist: {0!r}'.format(fileobj))
IOError: File does not exist: u'C:/Pictures/2015/2015_01_06/Polaralign/Q07A9354.
wcs'

I tried this again with downsampling set to 1  and the same error appeared.

Astrotortilla still solved the image

Andy

[D4N]

It's saying your min scale is more than your max scale, check those in the Astrotortilla settings. I imagine Astrotortilla has some code to get around them being put in the wrong way around.

TSED70Q, iOptron Smart EQ pro, ASI-120MM, Finepix S5 pro.

[AndyKeogh]

It's saying your min scale is more than your max scale, check those in the Astrotortilla settings. I imagine Astrotortilla has some code to get around them being put in the wrong way around.

TSED70Q, iOptron Smart EQ pro, ASI-120MM, Finepix S5 pro.

PPA imports my Astrotortilla settings.  I tried turning them round in the config screen of PPA but I still had the same error.

I could try to plough through 1501 lines of python code;  oh and learn python at the same time .....  but I think Themos will get there quicker.

Andy

[Gonzo]

That's from my Star Adventurer, as it's clear night tonight, I'm going to test this polar alignment.