Moravian instruments, Inc., source:, printed: 23.11.2017 12:18:19

Main page  Products  Software

SIPS v3.6 released
 Probably the most prominent new feature of SIPS version 3.6 is its ability to switch to dark skin, which could better suit to eyes adopted to dark. But astronomers using SIPS to process scientific data will find numerous enhancements like possibility to switch between magnitude and flux when processing photometric data, added infrared J-K color index for catalogs containing J and K magnitudes, etc. Also completely reworked is how SIPS handles EXTENDED (multipart) FITS files, often created by software controlling cameras of large telescopes.

Dark and Light skin

While we never followed the “design over functionality” trend, so common in modern IT industry, aesthetically pleasant products and software user interface are always welcomed. this is why new SIPS adds another, dark skin to its light user interface introduces in version 3. The dark skin is preferred by some user for everyday work (almost every modern software, including web browsers and the OS shell itself often allow switching to dark mode), but it can be especially appreciated by astronomers operating the software with eyes adopted to dark.

The SIPS skin mode can be switched anytime from menu View -> Switch skin or by clicking the respective tool button.

Multipart FITS handling

Especially large observatory telescopes, equipped with cameras containing multiple individual CCD sensors, store images in the multipart FITS (FITS keyword EXTENDED indicates the file contains more than image matrix).

Historically SIPS opened such files into image sets, each containing individual frames. These frames “remembered” they are part of multipart FITS and kept reference to the master image set. This brought several problems, like what to do with multipart FITS frames, opened into individual windows, when the master set is closed etc.


Actually, SIPS version 2.4.9 harmed multipart FITS handling by introduction of early test for SIMPLE keywords, which is naturally missing in individual multipart FITS frames (only the master FITS header begins with SIMPLE keyword). SIPS version 3.5.2 fixed this problem.

SIPS version 3.6 changed multipart FITS handling. EXTENDED FITS files are still opened into image set as in older versions, but the permanent links between individual frames and master image set are no longer created. Instead every frame, contained in multipart FITS, is created as independent FITS image. Every frame file name is copied from the original multipart FITS file and frame index within multipart FITS in parentheses is added to the name. If for instance multipart FITS file named 'test.fits', containing three individual frames, is loaded, new set with three frames named 'test(0).fits', 'test(1).fits' and 'test(2).fits' is created.


Note individual frames in set are marked as modified (file names are followed with '*'), because in fact files corresponding to individual frames do no exists on disk, only the original multipart file. If they are saved, then it is possible to handle them as normal (non-extended) FITS files.

Photometry module extensions

Maybe the presence of the Photometry module is the most compelling reason to call SIPS Scientific Image Processing System. As SIPS is used in more and more research projects, we include new features needed by respective users.

New SIPS Photometry features in version 3.6 are not fundamental, but each one allows SIPS to be used in another research projects.

  • As Photometry module also calculates astrometry and thus uses the Field deformation correction feature, the actually active Field curvature description file is displayed in the Photometry window title (as well as in the Astrometry tool window title). Not to duplicate numerous tool buttons and dialog boxes, the ability to create, load and save Field curvature description remains only in the Astrometry module and Photometry only uses already defined curvature description. The description file name displayed in the Photometry window title then remains user if and which file is currently used.

  • The light curve pane can be newly switched between Magnitude and Flux. The Flux is still relative to the chosen comparison star(s).


    If the Flux is chosen over the Magnitude, also the photometry report is created in fluxes, not magnitudes.

  • Photometry report can now include star metadata in the next comment line. The metadata contains used catalog, star coordinates (if astrometry is calculated) and catalog information about matched star. Example of metadata line:

    #Catalog: UCAC4 RA: 20:10:56.37 Dec: 01:07:18.76 CatalogId: 535-122832 CatalogRA: 20:10:56.38 CatalogDec: 01:07:18.77 CatalogMag: 14.54 CatalogB-V: 0.87
  • A new column with J-K color index was added to the star sheet (used catalog data should provide J and K magnitudes to show J-K value).

  • B-V values read from UCAC4 catalog show empty string instead of value 0.00 if the catalog does not contain B and V magnitudes for the selected star.

SIPS is a freeware and can be downloaded from the Download section of this web site.