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fmhill
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Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5650078 - 01/29/13 11:19 AM

About the index files you have loaded, how you chose and loaded the indexes does not answer the question I asked, I want to know what range of files you actually have, i.e. 4005 to 4012 as an example. However that you downloaded 3.39GB index files causes me to guess you probably have them all...

What I am most concerned with is what the low numbered range you have is, mainly 4006 and below... I would move any index files above 4006 to a storage directory so AT does not see them when it is resolving...

About the "Field 1 did not solve,field objects 1-10" message, you will always get this, it means only that a resolve was not found in that index on the first pass. AT will make a number of passes through the indexes looking for a best fit and having indexes not needed for the FOV of your camera and telescope combination only slows the search for best fit down...

What I am most suspicious about, is the image size and format you are trying to resolve. I resolve JPG images approximately 2400 x 1500 pixels in size, and using a computer with an i3 2.6 Ghz CPU and Windows 7 Pro 64bit operationg system, a plate solve takes about 7 seconds to as long as 45 seconds on tough ones typically...

The key difference I see here from what you describe is the images and how you are getting them that you are attempting to solve... What I have heard from others although I have not run into it myself, is that AT is fussy about the image quality. Often images not directly from the camera will not resolve...

Therefore my suggestion would be to take imaged directly as downloaded from your camera, do a simple file type conversion to JPG without altering size or any other parameter, and see if they resolve...

I'm suspicious the reduced image size you are attempting to solve simply does not hold adequate resolution of data in JPG format at the reduced size... This seems to be the most significant difference between what I am resolving and what you are attempting to resolve...


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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: fmhill]
      #5651421 - 01/29/13 11:51 PM

The data file range I downloaded runs from 4002-4007. Would it help if I also downloaded the 4001 index files?

I am now converting directly from the raw camera files to JPEG and trying that out. My .jpeg frames are now a larger 1200x1600. The next time I will try to take them with an even higher resolution if you think that would help. I have the SBIG set to "Auto" image quality, but the next time I can set it to "High".

The Astrotortilla program occasionally freezes up on me and says "Not responding", but if I leave it alone for awhile and don't click on it with my mouse then it often works out the kink on its own and then continues sorting through the index files where it last left off.

It solved my first file in 7 minutes which was a picture of ngc2903 saved as a 2.2mg 1200x1600 jpeg file.

It was not able to solve the second photo of ngc891 which was a 1.89mg 1200x1600 Tiff file. I resaved the same file as a jpeg and it also was not able to solve it.

It then solved the Pleiades in just 46 seconds. I used the original 30sec exposure FITS file for solving.

I then stuck with FITS files for it seemed to love them. It solved the next 3 FITS pictures as follows: M95 in 27 seconds, M66 in 6 minutes 20 seconds, Flame Nebula in 14.2 seconds.

That's great and meets my needs exactly! I have learned how to freeze the time in Starry Night Pro, then set it back to the original time I took the FITS photo (as revealed in the FITS header), then click on "Edit" and then "Center On" and then enter the plate-solved coordinates, then Sync the telescope's gaze to the center of the screen (e.g. the plate-solved coordinates), and then change the time in Starry Night Pro back to the current/present time. I imagine this could be done with any telescope control program. In this way, I do not need to rush whatsoever in receiving the plate-solve results back from Astrometry.net or from the AstroTortilla program.

Thank you all for this excellent program


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fmhill
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Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5651443 - 01/30/13 12:18 AM

By all means, stick with the FITS file format, no need to convert to JPG. You did not explain in your prior posts that RAW files were in FITS format, only that you were using screen capture in JPG format... Converting to JPG format is only necessary if your raw files are in a format AT will not recognize...

As to index file 4001, the way to determine if this is necessary is to use the log view in "Tools" and keep a record of which indexes that resolves are completed with. If you see 4002 being used predominantly, then yes, having 4001 might allow AT to resolve the few that it is failing to resolve...

Unfortunately I know of no method of telling what indexes are necessary for a given FOV, all I know is that lower index numbers, i.e. 4002 resolves smaller FOV vs a higher number as 4007 being used for a larger FOV.

I have seen a post on a different forum where someone came up with a formula for relating FOV to Indexes however I do not have that information nor do I know how accurate it is... I think the best approach is to keep a record of what indexes are used the most with your images and as I suggested before, move the unused indexes to a storage folder/directory so they are not being scanned needlessly wasting time. And if you see the lowest numbered index being used often, then, yes, I would think adding the 4001 index is worth a try...

Glad to hear you are making progress...


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ldesign1
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Reged: 09/17/09

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Re: AstroTortilla 0.4 - easy to install! new [Re: fmhill]
      #5651487 - 01/30/13 12:52 AM

Quote:

Unfortunately I know of no method of telling what indexes are necessary for a given FOV, all I know is that lower index numbers, i.e. 4002 resolves smaller FOV vs a higher number as 4007 being used for a larger FOV.




If you go back to the AstroTortilla installation file, and select to install only the Index Files, you are allowed to choose the FOV range in arcminutes that you want to install. Don't go through with reinstalling the files. Just take note on which Index Files Correspond to which FOV.


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fmhill
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Loc: Cape Cod, Massachusetts, USA
Re: AstroTortilla 0.4 - easy to install! new [Re: ldesign1]
      #5651519 - 01/30/13 01:43 AM

Quote:

Quote:

Unfortunately I know of no method of telling what indexes are necessary for a given FOV, all I know is that lower index numbers, i.e. 4002 resolves smaller FOV vs a higher number as 4007 being used for a larger FOV.




If you go back to the AstroTortilla installation file, and select to install only the Index Files, you are allowed to choose the FOV range in arcminutes that you want to install. Don't go through with reinstalling the files. Just take note on which Index Files Correspond to which FOV.




You must have a different version than what I am using, I do not get any listing of files as you describe...

Any chance you could supply a screen shot in JPG mode of what you are suggesting?


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Vostok
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Reged: 03/23/08

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: fmhill]
      #5651542 - 01/30/13 02:22 AM

There is a descriptive list of FOVs related to different index levels in the AstroTortilla user guide at http://astrotortilla.comsix.fi/docs/AstroTortilla_user_guide.pdf and the same list in the installer program Ralph is talking about, at the step asking you to choose which indices to dowload. By the way if you select an index range that intersects some index files you already have on your hard disk, it won't download those levels.

And mind that the FOVs listed in the table correspond to the width of quads, which may span about 10% to 100% of your field size according to the astrometry.net documentation. There's an example calculation on which index files are suitable for a given FOV in the user guide.

And as Mitch said, you can examine which index levels astrometry.net is getting its solves to determine which levels to favor for your specific setup.


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fmhill
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Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: AstroTortilla 0.4 - easy to install! new [Re: Vostok]
      #5652079 - 01/30/13 11:18 AM

Part of the problem with determining a correlation between indexes and FOV, I have been using AT from 0.2.10 version on, presently at 0.3.0, and the user guide documentation has recently been upgraded within the past two weeks it would seem... I laud the group for this effort as I consider AT to be the most significant astronomical software development I have used to date...

However, using the formula and chart as listed in the new user guide results in a higher index number than what I find is used by AT in practice. I believe the documentation for using the formula and chart is misleading due to an ambiguity in description of sensor size. The standard form When using sensoir size in optical system calculations is to use the diagonal dimension of the sensor in mm. I have not fully tested the formula as described ro see what effect of using Sensor width vs Sensor maximum dimension (diagonal) to see if this corrects the FOV vs Index result.

Bottom line, this documentation of the FOV calculation needs to be modified to remove the ambiguity of sensor size to be used in the calculation in order for this method of selecting index information to be accurate. From my experience, it is incorrect and misleading as it presently is...


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Vostok
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Reged: 03/23/08

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: fmhill]
      #5652456 - 01/30/13 02:28 PM

Quote:

I believe the documentation for using the formula and chart is misleading due to an ambiguity in description of sensor size. The standard form When using sensoir size in optical system calculations is to use the diagonal dimension of the sensor in mm.




The formula works equally well for any of the directions the sensor size is given in, width, height or diagonal. It just maps a distance on the imaging plane onto an angular value on the sky. That is, if you input the length of your sensor diagonal in mm, you get your diagonal FOV in degrees.

The reason for not specifying to use the diagonal exclusively is not to burden users with unnecessary calculations. For instance a google search for "40D sensor size" results in many hits only specifying the width and height. Obviously it's easy to work out the diagonal size from those if you know who Pythagoras was, but it's unnecessary and out of the scope for the AstroTortilla user guide. After all, with normal sensor shapes, the width, height and diagonal are all of same order of magnitude which is the important quantity to be considered here.

The ambiguity of the index levels to choose is because of the astrometry.net solver engine behavior which depends on loads of factors. The quads recognized from a plate range from 10% to 100% of the field size according to astrometry.net documentation and therefore span several levels of incides as they are.

The user guide calculation example is a guideline and not meant to be used for optimizing the solving performance, but for getting new users in the right ball park to be able to start using the software quickly.

We're looking forward to creating a detailed optimization guide regarding the different solver command line parameters as well as narrowing down the index ranges for the solver to choose from to speed things up.

If any of you got a good grasp of what indices (plural of index, btw ) the solver typically favors above others, we'd be happy to collect this information together with information about the FOV you use and perhaps a description of your imaging setup too (focal length and camera used, and typical appearance of the ~5s frames captured by AstroTortilla).

Lauri


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Vostok
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Reged: 03/23/08

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5652464 - 01/30/13 02:32 PM

Regarding which indices to choose, IanL put up a nice description at Astronomy Shed:

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=54&t=11579&start...


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Aimo
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Reged: 01/28/10

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: fmhill]
      #5652491 - 01/30/13 02:47 PM

The more detailed indexes come into play when shooting at a sparse star fields, where there might not be enough stars meeting the criteria at the higher level indexes. You don't have to move the index files anywhere from the default location, you can either create a per-system (scope+camera) backend.cfg -file, or use the scale limits to make the solver skip files not related to the FOV range. This FOV range can be adjusted automatically on your first blind solve when theScale Refinement in the AT config grid is non-zero, e.g. 0.1 for 10% variance.

The relatively small images are likely a major problem, as the limits by default are fairly tight for fitting the star patterns. The solve-field command takes several command line arguments for setting the solving parameters, such as accuracy limits. Increasing the pattern match threshold can also cause false positives more easily. If your FOV is about 30x20 arcmin, the likely indexes for finding a solution are in the range of 4004-4006, with occasional hits in 4003. A good way to check you image quality is the number of stars detected, it should be in the range of 200-300. You can use the AT log window to see this figure among the first lines of the solver run. Below settings are likely to yield a better result:

downscale = 0
scale_max = 30
scale_xrefine = 0.1
scale_low = 20
searchradius = 180
year_epoch = JNOW
scale_units = arcminwidth


-Antti


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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: Aimo]
      #5655089 - 01/31/13 09:11 PM

Thanks, Aimo! Just like before, it still does not solve about 20-25% of the photos I feed into it, but if it is going to eventually plate-solve a specific photo it now does it in record time (15-20secs) thanks to the settings you suggested.

At least some of the photos that I feed into it are not in very star-rich areas. This is true even though I am using high-definition settings for the photos and am using 30sec FITS shots (3.83mgs files). I don't know what else to do about that except to roam around a bit in the immediate area with the scope until I find a more star-rich area. Sometimes I can do that rather quickly but other times I have to slew to several different areas before I find one that has enough stars. I guess that sounds about normal and is just the nature of the ballgame

Thanks again!


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Aimo
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Reged: 01/28/10

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5671949 - 02/10/13 08:12 AM

The 1 out of 5 not solving doesn't sound right. I use 2-10 second exposures with 2x2 binning on my C8 and SXVR-H18 (KAF-8300 sensor), and I have set the --sigma flag to get between 200 to 500 stars (as indicated by the line "simplexy: Found N sources." in the logs) with the exposure depending on the proximity to galactic plane.

This gives me a solution rate of 100%, solve times range between 30s to 50s on my old netbook. The --sigma is fully camera dependant, it sets the noise level of the shot to the given floating point value. You can also use the --objs N to cull the object count and reduce your --sigma, this should give a more consistent solve time without changing the exposures across the sky.

Sample run-times on my desktop for a picture of M42 (averages of three runs):
"--sigma 100" found 139 sources, solved in 4.5s
"--sigma 50" found 341 sources, solved in 4.6s
"--sigma 10" found 1342 sources, solved in 6.0s
"--sigma 10 --objs 150" solved in 5.6s
"--sigma 0 --objs 150" found 2622 sources and solves in 12 seconds, extracting the sources with sigma=0 took 8 seconds and without object count limit the actual solve took one second longer.

Granted, I use the 200-series indexes. With the 4000 series indexes you might want to add the extra flags "-c 0.02 -r" meaning it relaxes the star pattern accuracy a bit and re-sorts the found objects by brightess if possible. This gives me a solution in 8 seconds with the same image.

-Antti


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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: Vostok]
      #5677473 - 02/13/13 11:16 AM

Can anyone share with me where I can download and convert (if necessary) the 200-series data files? Any help you can provide would be greatly appreciated. Please be as detailed as possible and email me privately if you prefer. Thanks!

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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: Aimo]
      #5677617 - 02/13/13 12:38 PM

Antii, thanks for your comments. Unfortunately, I have never gotten anywhere near "simplexy: found 200 sources". Usually I get about 8-35 but the highest I have ever gotten was around 135. I figured it was just counting the number of stars visible in the picture frame I had submitted for solving, so never thought more about it. What could be going wrong here? I am using FITS file that 30sec exposures with darks automatically subtracted.

If possible, please tell me how I can include the USNO A 2.0 files in the search database as well. I already have the entire database downloaded onto my C:/ drive so if I can simply add another string to the Astrotortilla program that tells the program where to search for this other database then that would be great! However, the USNO A 2.0 database files are saved as .acc and .cat files as downloaded from the Naval site. I notice that the 4000 series files used by Astrotortilla program are all .FITS files, so can Astrotortilla even use the standard USNO .acc files, or will I have to somehow convert them to FITS files first? If I need to convert them, how do I do that?

I would really like to download and use the "old" but evidently better (for Astrotortilla) 200-series files.

Concerning the insertion of further flags that you mentioned, where do I insert that into the .cfg file? Should it be right after the sigma information so that the entire configuration line reads "--sigma 0 -c 0.02 -r --no-plots -N none" ?

Thanks for all of your help!


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Vostok
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Reged: 03/23/08

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5677986 - 02/13/13 04:45 PM

You can't use the USNO catalog directly, that's not how the astrometry.net solver engine works. The solver uses pre-built lists of four star patterns calculated based on the catalog.

It's a huge computational effort and that's precisely the reason blind plate solving is possible in the first place -- most of the computation needed is already done when building the indexes. That leaves your computer with just the task of searching them through.

The 200-series are not under a free GPL license, but they can be obtained with permission. You can read more about acquiring a download link (and other licensing stuff) here: http://trac.astrometry.net/browser/trunk/src/astrometry/GETTING-INDICES?rev=1... (i suppose that email would still work?). You can, for example, describe to them that you wish to compare the solving process with different index sets.

Lauri


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Vostok
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Re: AstroTortilla 0.4 - easy to install! new [Re: Vostok]
      #5677989 - 02/13/13 04:47 PM

And regarding the configuration options, you enter them at the "Custom options" line in the solver configuration table at the main AstroTortilla window.

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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: Vostok]
      #5679003 - 02/14/13 09:23 AM

There is no email address listed on the Astrotortilla website that enables me to request the series 200 index files. Can you please give me the appropriate email address or otherwise give me access to the 200-series data files?

I can post my picture on to the nova.astrotortilla.net website and get a solve after just 6.5 seconds. That online site uses the series 200 index files. When trying to get a solve with the downloadable version that uses the 4000 series index data files (star data bases), it will not solve regardless of how much time I allow it to try.


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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5680210 - 02/14/13 09:03 PM

I was able to locate the Astrometry.net email address. Thanks!

Concerning the customized settings while using the 4000 series data files, below is a screenshot of what the program displays when I first open it up. Under "Custom options", I have tried adding the custom settings "-c 0.02 -r" to the end of the string that is already displayed. I have also tried deleting the settings that are already displaying and in their place just putting the new settings. Neither method seemed to work. Any other suggestions?

Thanks again for your patience!




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Aimo
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Reged: 01/28/10

Loc: Finland
Re: AstroTortilla 0.4 - easy to install! new [Re: LoveChina61]
      #5683577 - 02/16/13 01:55 PM

If you end up with very few stars detected, you should definitely reduce the sigma-value, which sets the noise floor level. And if you are using stretched images, all bets are off, as the relative brighnesses of stars vs background are possibly way off. I don't know what the setup in nova.astrometry.net is for the star extraction and sorting and there are some areas of sky where the 4000 series definitely has a clear disadvantage.

If your FOV is not within the limits set by Scale minimum and Scame maximum, it will never find a solution even if an otherwise suitable match is found, as it doesn't fit the limits.

-Antti


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LoveChina61
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Re: AstroTortilla 0.4 - easy to install! new [Re: Aimo]
      #5763711 - 03/29/13 06:19 AM

Thought I would give a quick update since I have downloaded the 200-series star database files and have been using them to plate solve. In short, they seem to work better for me than the 4000 series files but still are not perfect. If I take at least a 30 second exposure and subtract a dark, then the odds of success are considerably higher.

I find that downloading the 200-series files and then performing plate solving from the Tortilla desktop application has about the same success rate as the online version found at nova.astrometry.net. However, the online version can plate solve quite a bit faster in many cases.

A few times I have had to slew to an area of the sky which had more stars in it in order to finally get a plate solve. For example, I never could seem to get a plate solve in the immediate area surrounding M5. But after slewing to a more star-populated area, I was able to do an accurate plate solve and then sync solidly to M5.

The downloadable Astrotorlilla program works! While Sky6 and most other programs only allow a plate solve somewhere in the immediate area of where it already knows the scope is pointing, Astrotortilla's ability to do a "blind solve" across the entire heavens is quite a valuable tool indeed. Thanks again to the authors who have contributed this program to us all for free!


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