Photon Calibration Release

The direction of developing of Munipack during last half-year has been strongly influenced by application of Munipack on data archive in Ondřejov Observatory. I had developing a set of scripts which are suitable for processing of large archives of frames: Astromill. Currently, Astromill is prepared for the particular case, but I plan more general utility, at least for peoples having good grasp in computer programming.

Developing of Astromill contributes tree new important features into Munipack:

Photometry Calibration

The very precise calibration of the Ondřejov archive leaded to deep improvements in the calibration. The maximum precision can be only reached when colour calibration is carefully prepared, which me forced, to construct own catalogue for observed fields because there is no a photometry catalogue which covers all the sky with required precision.

An impact of (un)precise of various calibration methods may be illustrated on light curves, all night observation, which I prepared for new version of light curves tutorial. The best results are achieved by the way:

• (approximate) calibration of a carefully selected reference frame against to a catalogue (standard field stars) in absolute fluxes.
• And follow up calibration of all other frames against to the reference.

Much better results can be reached with construction of own catalogue from all frames. It is challenge for me. Preliminary version is implemented in AstroMill. It averages frames and corrects colour extinction. Unfortunately, Munipack is not offer such tool for the task now.

Flat-fields

I've very sad news. All flat-fields which has been generated by flat utility were wrong. At least, they was been imprecise.

All the previous implementations used only robust averaging of the frames with scaling. Both the average mean and the dispersion were scaled independently. It's important for series of twilight shots.

I developed a new algorithm which scales only levels because dispersion is scaled together (thanks to property of photon noise) for known gain. Flat-fields are constructed in two steps:

• averaged flat,
• new scaling against to the flat and new averaging.

The precision is order of 1/1000 and as the side effect, gain can be estimated during the process.

Packages Repository

Thanks to official availability of wxWidgets in version 3.0 since June 2014 (link), and including of the wxWidgets libraries in ordinary releases of Ubuntu and Fedora, I updated build scripts for preparation of DEB and RPM packages. So the bundle installation way is not more required (and is obsolete now) and the standard way for installation of packages is supported and recommended. There is nothing to block including of Munipack into main GNU/Linux distributions, I hope.

Also I prepared own repositories for Ubuntu and Debian enabling easy installation and automatics system updates.