AstroTortilla stores its configuration files in the user's application local settings directory structure, under the astrotortilla.sf.net\AstroTortilla directory. You can also store additional (partial) configuration files for quickly switching between various setups. It is recommended you save the configuration files into the default directory. You can remove any unwanted sections from the saved configuration files, e.g. leave only the solver specific section in the files. This enable creating a quickly switchable profile library for different telescopes and for annotated plots from stacked images.
The configuration file structure uses the familiar INI-file structure and it is currently in 7bit ASCII only. The percent -sign (
%) must be escaped with another escaped-sign in the configuration file.
# Comment [SectionName] option = value another_option = different value
There is no need to have any particular section present in a configuration file, and it is recommended you edit the additional saved configuration files to cover only the parts of AstroTortilla settings you want to change quickly and easily on the field.
A sample of configuration file sections:
[AstroTortilla] settings_path = C:\Users\MyUserId\AppData\Local\astrotortilla.sf.net\AstroTortilla log_file = log_level = ERROR last_gotoimage = work_directory = s:\tmp
|settings_path||reserved for future use|
|log_file||Log file name (name only or absolute path)|
|log_level||DEBUG, INFO, WARNING or ERROR|
|last_gotoimage||reserved for future use|
|work_directory||If set, all work will be done under the given directory. The temporary data is not deleted at exit.|
[Session] iterlimitarcmin = 1.0 iterlimitcount = 5 solver = AstrometryNetSolver syncmode = 0 exposure = 5.0 camera = CaptureCamera
|iterlimitarcmin||Accuracy limit for iterative GoTo correction|
|iterlimitcount||Maximum number of successive correction iterations|
|solver||Last used solver module|
|syncmode||Last used synchronization mode|
|exposure||Default exposure time in seconds|
|camera||Last used camera module|
[Solver-AstrometryNetSolver] shell = S:\cygwin\bin\bash --login -c "%%s" downscale = 0 scale_max = 4 scale_xrefine = 0 configfile = /etc/astrometry/backend.cfg scale_low = .5 xtra = --sigma 50 -N none --no-plot searchradius = 180 scale_units = degwidth year_epoch = JNOW
|shell||Execution string for using astrometry.net undec Cygwin. Note that |
|downscale||Image downscaling factor (0=disabled)|
|scale_max||Upper limit for image scale|
|scale_low||Lower limit for image scale|
|scale_xrefine||Factor for setting the |
|scale_units||degwidth, arcminwidth or arcsecperpix|
|configfile||Path to astrometry.net configuration file (in Cygwin)|
|xtra||Additional command line options to solve-field|
|searchradius||Assumed telescope pointing accuracy radius (180=whole sky)|
|year_epoch||Epoch used in solution coordinates, JNow or J2000|
If you see a systematic error of a few arc-minutes, you can try changing the epoch setting.
The fastest way to solve an image is to use a
scale_low a bit smaller than your actual image size and
searchradius of around 45 degrees (eg EQASCOM cannot sync with >45degree mismatch), to use binning instead of down-scaling, to disable plotting and to optimize the exposure-time and
--sigma values for approximately 100-200 stars. One additional performance test is to make sure your Cygwin doesn't have Bash autocomplete enabled, it can add several seconds to the solve time if enabled.
The search radius and RA/dec information is not used when solving an image from "GoTo image" or "Add bookmark from image".
[Telescope-ASCOMTelescope] propertyagelimit = 1.0 syncaccuracy = 1.0 syncmaxwait = 2.0 lastselection = ASCOM.Simulator.Telescope
|propertyagelimit||Minimum telescope property refresh interval|
|syncaccuracy||Post-sync reported coordinate accuracy limit|
|syncmaxwait||Timeout limit for sync-operation|
|lastselection||Last used ASCOM Telescope device name|
[Bookmarks] bm-0 = 21h29m58.57s,12:10:15.59,1.0,M15 bm-1 = 05h34m48.42s,-05:38:06.04,-3.5,M45 count = 2
This format is subject to change.
|bm-*||Bookmark entry RA,dec,rotation,name|
|count||Number of bookmarks (last+1)|
Camera specific sections:
[Camera-MaximDLCamera] filter = -1 binning = 2 [Camera-ASCOMCamera] lastcamera = binning = 1 [Camera-FileOpenCamera] directory = S:\tmp binning = 1 [Camera-APTCamera] binning = 1 hostname = localhost port = 21701 [Camera-CaptureCamera] windowtitle = ^PHD Guiding.* topmargin = 49 rightmargin = 48 classname = .* bottommargin = 70 leftmargin = 3 binning = 1 [Camera-NebulosityCamera] path = C:\Program Files\Nebulosity2\ setfilterwheel = -1 setcamera = False setextfilterwheel = -1 resetpath = binning = 1 nebulosity = 2
Various camera specific settings.
The MaxImDL and Nebulosity camera modules support using a specific filter for solved images. Setting a filter value to -1 means current filter, any other value is passed as filter index to supporting imaging software.
Binning is always set as symmetric, and it's supported by MaxImDL, Nebulosity and ASCOM camera modules.
Nebulosity module cannot detect current imaging directory from Nebulosity and thus it has to set the imaging directory to a temporary one. If the
resetpath is set, the given value is set as imaging directory after the image for plate-solving is taken. The
resetpath option supports following parameters (use escaped form in configuration file):
|%(night)s||Date 12 hours ago|
The date format is YYYY-mm-dd. The current image name in Nebulosity is not changed.
Nebulosity module has been tested with Nebulosity 2.4 and 2.5 only. Nebulosity 3 may work, but it has not been tested. Set the
nebulosity option to "3" instead of "2" and point the
path to your Nebulosity 3 installation directory.
The astrometry.net plate-solver engine is used to determine the location, orientation and coverage of the imaged star field. The majority of the command-line options for solve-field can be set thru the
xtra configuration entry or thru the GUI entry Custom options.
Reserved options not available as custom options (showing only short variants):
|-D||Working directory (thru AstroTortilla config file)|
|-b||Configuration file location (thru AstroTortilla)|
|-L||Scale low limit (thru AstroTortilla)|
|-H||Scale high limit (thru AstroTortilla)|
|-u||Scale unit settings (thru AstroTortilla)|
|-3||Target RA (from telescope if applicable)|
|-4||Target declination (from telescope if applicable)|
|-5||Search radius (thru AstroTortilla)|
|-z||Downscaling factor (thru AstroTortilla)|
|Any/all options changing output file locations and names|
Recommended options to experiment with:
|--sigma N||Set the noise level to N|
|--no-plots||Do not plot the annotated image|
|--N none||Do not create a new FITS file with integrated WCS headers|
|-q N.N||Minimum quad size fraction|
|-Q N.N||Maximum quad size fraction|
|--odds-*||See astrometry.net documentation|
|--parity neg|pos||Try only negative/positive parity|
|--objs N||Limit source list to N objects|
|--resort||Sort stars by background calibrated flux|
|--no-fits2fits||Don't sanitize FITS files|
|--no-background-subtraction||Don't estimate background fluctuations|
|--guess-scale||Try to estimate field size from FITS headers|
--sigma option can be used in conjuction with the exposure time to improve the detected stars SNR and limit the number of items interpreted as stars. Depending on your camera and telescope aperture the known good values are known to vary between 2-5 seconds of exposure and 5-200 units for
If you have a fairly slow harddisk (e.g. netbooks), disabling the plotting functions can improve you solve time by over ten seconds. These are set to disabled by default in new installations.
If you want to solve images on disk and store the annotated images from astrometry.net solver, remove the
--no-plots -N none options and set the
work_directory in the configuration file to a temporary directory. Using the FileOpenCamera module you can annotate existing stacked images and the results are stored in solving order under the work directory.