Software Bisque

Take a virtual tour of the Software Bisque campus Watch Steve Bisque discuss the Paramount mount with S&T's Dennis Di Cicco Read the Paramount MYT Review Read about the Paramount Software Suite

Closed loop slew and auto image linking

rated by 0 users
This post has 11 Replies | 2 Followers

Not Ranked
Posts 34
jackovks Posted: 02-22-2018 9:12 AM

Hello all,

I am having some difficulties performing the closed loop slewing for my telescope and the image linking with known FOV parameters.  I have a Meade LX200 ACF 12" that has a wedge, making it an equatorial mount, instead of an Alt-Az.  Mounted to the top of the telescope is a 50mm spotting scope with an autoguider camera attached to the back.

I was able to link the autoguider camera to the SkyX software without any difficulties.  Then, when I capture an image, I save it as a Fitts image, then send it to image link, and finally match it to the sky based on unknown FOV parameters.  The images have plenty of stars in the FOV and the thresholding parameters are fine.

The problem that I have is that when I set the known parameters of my camera, image link does not seem to come up with an answer.  Often, the process will time out after a few minutes.  I entered the correct FOV into SkyX, so that should be correct.  The same goes with the closed loop slew.  It slews, takes a photo, and then stops at the image linking, saying it cannot find the position in the sky.

Do I need to hook the autoguider up to the telescope?  I have not done this.  Are there any additional settings that need to be put in place?  I read through the guide, but I did not see anything that I missed.  Thanks,

Kevin

Top 10 Contributor
Posts 26,926
Software Bisque Employee

jackovks:

The problem that I have is that when I set the known parameters of my camera, image link does not seem to come up with an answer.  Often, the process will time out after a few minutes.  I entered the correct FOV into SkyX, so that should be correct.  The same goes with the closed loop slew.  It slews, takes a photo, and then stops at the image linking, saying it cannot find the position in the sky.

Please share a sample FITS photo that exhibits this behavior.  

jackovks:
Are there any additional settings that need to be put in place?  I read through the guide, but I did not see anything that I missed. 
Image Link Troubleshooting covers many common issues.  Getting a sample FITS will really help.

Daniel R. Bisque

Software Bisque, Inc.

862 Brickyard Circle

Golden, Colorado 80403-8058

Office Hours: 8 a.m.-5 p.m. Monday-Friday GMT-7:00

Posting Etiquette

Top 150 Contributor
Posts 188

Why use the guide camera and scope for Image Link Slews?  I use my main scope and camera.

Top 150 Contributor
Posts 188

Do I need to hook the autoguider up to the telescope?  I have not done this.

 

What is meant by this statement?

Not Ranked
Posts 34

I have attached an example of one of the Fits files that I collected.  I can see multiple stars and I have no problem linking when the FOV parameters are unknown.  I will check the guide later tonight for troubleshooting solutions.

My main camera is not supported by the SkyX software, so I cannot use this.

The autoguiding camera is hooked up to my computer, but is not connected to the telescope directly.  Meade telescopes have an autoguiding port on there control box.  I have not hooked up to that.

Not Ranked
Posts 34

My main camera is not supported by the SkyX software, so I cannot use this.

 

The autoguiding camera is hooked up to my computer, but is not connected to the telescope directly.  Meade telescopes have an autoguiding port on there control box.  I have not hooked up to that.

Not Ranked
Posts 34

Here is my example file.

Not Ranked
Posts 34

Sorry about repeating messages.  I thought the first one did not get posted.

Top 10 Contributor
Posts 26,926
Software Bisque Employee

jackovks:
I have attached an example of one of the Fits files that I collected. 
Thank you.

jackovks:
can see multiple stars and I have no problem linking when the FOV parameters are unknown.  I will check the guide later tonight for troubleshooting solutions.
Thank you for reviewing the troubleshooting tips.  This photo is a good example of a "very poor Image Link candidate" photo.

  • Look at the histogram for the photo.  There's virtually no signal. 
  • Take longer exposures to get more signal (better signal to noise ratio). 
  • While the human brain can easily detect multiple light sources in the photo, the algorithm that detects light sources generally requires a higher signal to noise ratio to do the same. 

That said, Image Link and All Sky Image Link (using either the Blind and Known Image Scale) are still successful:

Standard Image Link Results (unknown image scale):

******** ASTROMETRIC SOLUTION RESULTS ********

Center RA (2000.0): 06h 38m 16.52s

Center Dec (2000.0): +16° 21' 53.2"

Scale: 4.38 arcseconds/pixel

Size (pixels): 1280 x 960

Angular Size: 1° 33' 32" x 1° 10' 09"

Position Angle: 322° 41' from north through east

Mirror Image: No

RMS: 0.79 (X: 0.74 Y: 0.26)

Number of Stars Used in Solution: 7 (100%)

FWHM: 5.62 pixels, 24.62 arcseconds

***********************************************

 

...

 

Image Link Succeeded.

 

All Sky (Known Image Scale option) Results:

 

 

******** ASTROMETRIC SOLUTION RESULTS ********

Center RA (2000.0): 06h 38m 16.52s

Center Dec (2000.0): +16° 21' 53.2"

Scale: 4.38 arcseconds/pixel

Size (pixels): 1280 x 960

Angular Size: 1° 33' 32" x 1° 10' 09"

Position Angle: 322° 41' from north through east

Mirror Image: No

RMS: 0.79 (X: 0.74 Y: 0.26)

Number of Stars Used in Solution: 7 (100%)

FWHM: 5.62 pixels, 24.62 arcseconds

***********************************************

 

...All Sky Image Link Succeeded. Found solution in Gemini.

Done

 

Remarkable, IMO.

Daniel R. Bisque

Software Bisque, Inc.

862 Brickyard Circle

Golden, Colorado 80403-8058

Office Hours: 8 a.m.-5 p.m. Monday-Friday GMT-7:00

Posting Etiquette

Top 25 Contributor
Posts 1,508

Hi, I'm just another customer, and have own a few Meade scopes, and may be able to help a bit.

I had a fast look at your FITS image.

Have you licensed TheSkyX Pro ? If so, don't use the presales questions section of the forum, you'll get more help in the right section.

 

Please tell us a bit more about your setup - Are you running Windows 10 64bit or Mac OS?  What is your main camera and autoguider camera?

Some recommendations:

1. For starters, you are on an old verson of TheSkyX.  There were quite a few improvements made since that one.  If you own TSX Pro on Windows, go get the latest Daily Build 10.5.0 11360 from here:

http://www.bisque.com/sc/media/p/45603.aspx

2. In TSX, set up the optical parameters of your Autoguider telescope - eg the 50mm.  I plate solved it using PinPoint/MaxIm and USNOA2.0 catalog, and got:

Focal Length 176.4 mm, Scale  4.383 "/Pixel

Average residual 0.5 arcsec; order 1
RA 06h 38m 16.5s,  Dec +16° 21' 57.1"
Pos Angle +322° 42.8', FL 176.5 mm, 4.38"/Pixel

You'll also want to rotate your camera (about 48 degrees) so that the Pos Angle is 0 or 180. eg. get the chip lined up with the axes of motion of the LX200ACF.

3. It looks like your guide scope had dew on it, or it's a bit dirty or has a focus problem - there are halos around the stars, and they aren't particularly sharp. You'll want to improve the focus.  Use a mid-brightness star - the one in the middle of your test image is too blown out to be helpful for getting great focus.

4. Your main camera

You mention your main camera is not supported, and that is a bit unlikely - you may be able to get it to go with ASCOM if it doesnt have a native X2 driver for TSX. I see you are using ASCOM with your guider. What camera is it?

I think once you sort those things out, you'll be good to have another go at this.

Cheers,

Colin

Top 10 Contributor
Posts 3,346
Software Bisque Employee

jackovks:
Do I need to hook the autoguider up to the telescope?  I have not done this.

Not in connection with the Image Link tool, no. Connecting a guiding camera's guider port to that of the mount/controller is optionally used for autoguiding, but has no relevance to performing an Image Link (astrometric solution).

jackovks:
Sorry about repeating messages.  I thought the first one did not get posted.

That's because this thread is on our Contact Software Bisque (Moderated Forum); posts don't appear here until we've approved them. As Colin suggests, posting such questions to our TheSkyX Professional Edition forum would be better. Your member account does need to have a relevant product registered in order to access a forum other than this public, but moderated, one.

Brian S. Rickard
Software Bisque, Inc.

Not Ranked
Posts 34

 

Thanks for all the help everyone and sorry for posting in the wrong location.  I will change where I post my questions from now on.

 

Last night I was very successful with the software and my telescope.  I think the issue was a combination of the low exposure time, dust on the lenses, and the field of view being set higher than what it is (set to 4.8 arcseconds per pixel instead of 4.4).  After I changed these parameters and fixed the other issues, I was able to do closed loop slewing, the full automated T-Point model calibration, and the accurate polar alignment procedure.

 

For now, it seems everything is working well with the closed loop slewing.  I have a few additional question on another topic, but I will post those in the correct location.

 

Colin – I have a FLIR camera on the back of my telescope.  There might be an ASCOM driver out for this camera, but I have not looked into it.  For now, the spotting scope camera is working just fine.

Page 1 of 1 (12 items) | RSS

   

© 2018 Software Bisque, Inc. 862 Brickyard Circle, Golden, CO 80403-8058 USA - phone: +1 303 278 4478 fax: +1 303 278 0045
Google+