Blind Solver

[vicent_peris]

...
it would be great if the script outputs a text file with the equatorial coordinates of the center of the images. This would be, through an image container, a valuable tool to make a telescope pointing model.
...

Yes, indeed an interesting idea. Only I dont know how I can generate a filename while processing an image container. The image view that the script sees has a more or less random name, if I remember correctly. Is there a way to find the original file name of a view while being called from an image container? Juan?

Georg

In fact, I think this can work without outputting the filenames, if you have stablished a clear naming order: you know that the second coordinate is for your second image.


V.

[georg.viehoever]

Vincent,

...
it would be great if the script outputs a text file with the equatorial coordinates of the center of the images. This would be, through an image container, a valuable tool to make a telescope pointing model.

At my Univ's observatory, we have an altazimuth telescope that can generate a pointing model from offsets measurements. Knowing the altazimuth coordinates of each of the pointing images, we can calculate the altazimuth offsets from the equatorial offsets. So, in case of ouputting a text file with the eq coordinates of each image, we only need an spreadsheet to transform those offsets.
...

Would you need equatorial coordinates (RA, DEC) or horizontal coordinates (Alt/Az) http://en.wikipedia.org/wiki/Celestial_coordinate_system ? RA/DEC is already computed by the Blind Solver (but not stored). Alt/Az of course is slightly more difficult, since this depends on your geographical location and time of day, but this could be done as well.

Georg

[vicent_peris]

This scope has an altazimuth mount. So it generates the pointing model by analizing deviations in altitude and azimuth coordinates. For each image I acquire, I write the altaz coordinates of the telescope. What we were planning is to calculate the coordinates of each image, and then make a spreadsheet that make the transformation between alt&az deviation and AR&Dec deviation. This is done simply by knowing the altaz coordinates of each image: you can calculate the angle between the two coordinates systems in that altaz coordinates and then turn the altaz deviation.


Vicent.

[georg.viehoever]

This scope has an altazimuth mount. So it generates the pointing model by analizing deviations in altitude and azimuth coordinates. For each image I acquire, I write the altaz coordinates of the telescope. What we were planning is to calculate the coordinates of each image, and then make a spreadsheet that make the transformation between alt&az deviation and AR&Dec deviation. This is done simply by knowing the altaz coordinates of each image: you can calculate the angle between the two coordinates systems in that altaz coordinates and then turn the altaz deviation.
...

But alt-az coordinates change depending on the time of day, dont they? For example, during sunset the alt-coordinate of the sun is 0? So you must consider the tme at which you shot the image when you convert between alt/az and RA/Dec equatorial coordinates. Or am I getting something wrong here?

Georg

[vicent_peris]

This scope has an altazimuth mount. So it generates the pointing model by analizing deviations in altitude and azimuth coordinates. For each image I acquire, I write the altaz coordinates of the telescope. What we were planning is to calculate the coordinates of each image, and then make a spreadsheet that make the transformation between alt&az deviation and AR&Dec deviation. This is done simply by knowing the altaz coordinates of each image: you can calculate the angle between the two coordinates systems in that altaz coordinates and then turn the altaz deviation.
...

But alt-az coordinates change depending on the time of day, dont they? For example, during sunset the alt-coordinate of the sun is 0? So you must consider the tme at which you shot the image when you convert between alt/az and RA/Dec equatorial coordinates. Or am I getting something wrong here?

Georg

No. For pointing model, you mast take the altaz coordinates of the mount exclusively. In my case, I wrote the altaz coordinates in my notebook at the time of acquiring each pointing model image. Then, all you need is geographic latitude and declination the telescope was pointing at. With these data, you can calculate the angle between declination and altitude at a known altaz coordinate, depending on the geographic latitude.


V.

[Nocturnal]

Somehow I missed this whole firestorm This is terrific work Georg! I've been solving my images with astrometry.net for some time and thought about creating a better labeler myself as the am.net one is a bit limited. Now I don't have to write this anymore, excellent!

I'll be trying this out soon.

[georg.viehoever]

Dear all,

attached is version 0.2.0 of the Blind Solver script. The main new feature is that it now supports writing a log file of the center coordinates and some other data, as requested by Vincent Peris in http://pixinsight.com/forum/index.php?topic=1857.msg11433#msg11433, to allow for creating pointing files. I am sure the community will find other good uses for this feature as well. The GUI allows to select the log file via a file dialog. If the file does not yet exist, Blind solver adds a header line. After this, each solver run appends to the file. Example:

Code: [Select]

filePath;viewId;parity;orientation;ra_center_hms;dec_center_dms;ra_center;dec_center;fieldw;fieldh;fieldunits
/home/georg/host/Pictures/2009_07_16_dachfenster_35mm/light (77).CR2;P7v2uLpcyj;1;171.35971;18:48:15;+1:32:10.5;282.062505381;1.53624216317;34.9;23.35;degrees
/home/georg/host/Pictures/2009_07_16_dachfenster_35mm/light (78).CR2;bIt7gqKidu;1;171.14811;18:48:54.5;+1:36:32.5;282.227113334;1.60903882256;35.38;23.43;degrees
/home/georg/host/Pictures/2009_07_16_dachfenster_35mm/light (79).CR2;ZWb8rFScfD;1;171.53073;18:50:17;+1:40:14.3;282.570871552;1.67064480014;34.95;23.61;degrees
/home/georg/host/Pictures/2009_07_16_dachfenster_35mm/light (80).CR2;dSrYMOCa7v;1;171.5969;18:51:23.2;+1:41:24.7;282.846575225;1.69018135215;34.71;23.61;degrees
/home/georg/host/Pictures/test/testleotripletprocessed3.fit;testleotripletprocessed3;1;33.150186;11:19:46.1;+13:15:25.2;169.941936086;13.2569995649;51.85;68.06;arcminutes

This CSV format can directly be read by M$ Excel -if your country uses "." as a decimal separator (as in the US or UK, Germany uses ","  ). In Excel 2007, you can change the default in Excel-Options/Extended Settings.

The other changes are listed in the header of the file, copied below.

Georg

Release Notes for 0.2.0
         - BugFix: Include Parity in output
         - BugFix: get boolean parameters as booleans, not reals. May have affected
                   operation with image containers and stored instances
         - BugFix: Coordinates were not retrieved if none of the annotation options was active
         - BugFix: Grid-option for annotation did not work due to malformed command line
         - BugFix: Parameter bPlotConstellations was not properly saved in process instance (Image Container would not work)
         - Improvement: Some restructuring of sources, improved comments
         - Improvement: Output of coordinates into appended file (Vincent Peris request)
         - Improvement: avoid creating unnecessary plot files if no diagnostic files are requested to reduce run time
         - Improvement: report exceptions to console. Were silently caught previously.

[georg.viehoever]

Hello,

another improvement, released as version 0.3.0: I have added a "SIMBAD" button that will open Firefox directly with the found coordinates in the SIMBAD database http://simbad.u-strasbg.fr/simbad/ . See screenshot below.

Enjoy!

Georg

[georg.viehoever]

Hi,

here is a new version 0.4.0 of the Blind Solver script. It has a new option "FITS Keys" that will create a new image that has the WCS information embedded into FITS Keywords. This has the advantage of enabeling us to process it with other FITS+WCS aware astronomy tools, such as Aladin (http://aladin.u-strasbg.fr/) or ds9 (http://hea-www.harvard.edu/RD/ds9/, also available in the Fedora repositories). Currently, the image creation is a bit clumsy due to the FITS Keyword issues in PJSR (http://pixinsight.com/forum/index.php?topic=1908.0), but I hope to clean up the whole procedure when PI1.6.1 becomes available.

I used an early version of the script to create the annotated picture in http://pixinsight.com/forum/index.php?topic=1943.msg12248#msg12248. I plan to follow up with another example of how this can be used shortly.

Cheers,

Georg

[georg.viehoever]

Hi,

here is another example of how solved images can be used (see updated Blind Solver script in previous post). This is an annotated version of the image that originally triggered the whole Blind Solver Project, somewhere in the Virgo Cluster. I used Aladin to annotate the solved image, using the astronomical databases available to Aladin. In yellow are galaxies, in red other objects that have an entry in the Simbad database. Galaxies that have a measured magnitude have been annotated with names, and most of them are also visible in the image. All other galaxies are just ovals, and most of them are invisible in this shot.

The limiting magnitude of this image is around mag17 (determined by comparing visible stars to entries in the USNO-B1.0 catalog). The image also contains a visible quasar (the QSO right to IC796). I never thought I would catch one of these....

Enjoy,

Georg

[Nocturnal]

Hi,

Georg asked me to give this new script a try which of course immediately failed as I tried this on a Windows box. A quick read of this thread explained why

I use astrometry.net all the time, in fact I routinely solve my images and post the resulting URL next to my images in my gallery. The other neat thing astrometry.net does is provide a Google Earth KMZ file that will show your solved image overlayed in space. As you take more and more images you can see the patches of sky you've imaged. Neato.

Anyway, solving images through astrometry.net is pretty easy so I don't miss a built in solver just yet. I already have Elbrus to add WCS data to my FITS files if I want. Clearly there are some interesting uses for having the image coordinates, angle and scale defined and accessible to PI. I used the view in Google Earth of 4 mosaic panels to rotate them into place and figure out the right mosaic order. PI could potentially do this automatically but frankly I think this is one of those 'high cost - low benefit' features. If GE can already show mosaic panels so users can help the PI mosaic feature that's fine for me.

[georg.viehoever]

Hi,

here is a new version of the Blind Solver script. Main change is that it no longer needs the SystemCommand module, and thus should run on PI 1.61 (Linux) where SystemCommand is not yet availble. Apart from that, I made only slight changes to error handling.

Instead of SystemCommand, the script is using a JavaScript replacement instead. This replacement requires that you allow JavaScript to execute external commands. This setting can be changed in "Edit > Security Settings > Allow execution of commands from JavaScript scripts".

Enjoy,
Georg

[Nocturnal]

Hi,

just wanted to report I had some success building astrometry .34 using Cygwin. Unfortunately it doesn't solve my images yet but it does solve the examples so it's not completely dead. Working with Dustin to figure out what's going on.

One of the remaining problems is that plotxy reports netpbm isn't installed when in fact it is. Somehow the makefile doesn't detect netpbm, I'll have to figure out why. Without the graphics abilities the solver will still add WCS headers to FITS images which is very cool but I want the automated plotting as well.

[Niall Saunders]

Georg,

I am trying to follow the development here, and when I see a reference to <Cygwin> my mind tells me that this suggests that BlindSolver may yet be capable of running on a Windoze machine - am I right, or am I just trying to be 'too clever'

[Nocturnal]

A quick look at the cygwin site will tell you you are correct

That said it appears the astrometry install and build will not be trivial as it depends on lots of packages being installed to make the runtime work. This goes for both Linux and Cygwin installs. It is not clear to me that a pre-built cygwin astrometry.net distro can even be put together.

The future of this script may well be to integrate with astrometry.net rather than doing the solving locally.