2008-01-19

I seeking for a deep darkness...

I had a trip with aim to seek for an ideal place for our observations. The map of light pollution of Czech Republic is revealing a possible region near Tišnov town. A terrain is hilly around 500m above sea. Majority of roads is poor surfaced and a parking place (or any car's available place) is impossible to be found. Only one acceptable (and near of my ideal) is an "airport" (eg. a wider road) near small village Rojetín. It is probably an emergency or an agro airport without any facility. Rojetín is about 20km (twenty minutes) far from Tišnov. I taken shots of the "runway".

Both pictures has been taken at coordinates 49°21'25.638"N, 16°14'46.732"E. In my opinion, the place may satisfy of our requirements for a perfect horizont and ideal light conditions. A night's trip to the airport will be resolving....

2008-01-08

Rawtran

A digital photography is really amazing field of a new technology. I discovered another dimension of one during winter's holiday while I'm play with analyzing of pictures by a standard fotometrical way. I get view to a complicated world of a calibration of that devices. My first touch has been of a most lower level: a conversion of RAW images produced by a digital camera to my favorite FITS format.

A great part of known RAW formats should be recognized and decoded by famous utility dcraw. It satisfy most of my requirements but one creates no FITSes. Dave's recommended way how to transform dcraw's output PGM files to FITS is not ideal. The issue is a netpbm toolkit with a "non-astronomer's" conversion.

My response for the frustration is a small utility Rawran. It wraps of the dcraw, get a PGM data file via a pipe and rearrange the data in fashion:
  • a four RGGB pixels to intensity as a weighted sum
  • one to one data pixels
  • a three separate bands in one file

The utility is not too mature and it can be found in rawtran directory along my other projects.

Some examples of converted images by the first method can be found as FITS files (each about 6M): holmes.fits (zoomed parts of the images has been used in examples above), pleiades.fits, deeep_macocha.fits (a png version of the image has been published some time ago).

2008-01-04

New SBIG drivers

Thanks to J.Soldán, SBIG's new version of camera drivers has been updated month ago. An update of Nightview associated to the new drivers has been smooth. Today's tests of our (faculty's) ST-8 new camera (first light!) discovered a few unimportant bugs in a daemon's start by udev scripts (they would be corrected at now). The daemon (it directly talking to camera via updated drivers) seems to be a bugfix free. The drivers itself looks perfectly. All known bugfixes (a link to libusb and cwf typo in headers) has been corrected. It works on 64-bit systems!

I'd prepared an install_sbig_firmware.sh script to automatically install (fetch it, unpack, copy to appropriate place) of the drivers. To install Nightview on clear computer, download of latest nightview-????-??-??.tar.gz, unpack it, go to libsbig directory (if you can install camera driver) an run the script. Everything is prepared to run successfully a configure. There is a simplefirst-time installation way:

wget ftp://integral.physics.muni.cz/pub/nightview/nightview_2008-01-04.tar.gz
tar zxf nightview_2008-01-04.tar.gz
cd nightview/libsbig
./install_sbig_firmware.sh

cd ..

./configure

make

make install


The presented commands will install all needs. A switch-on of a power button will start firmware loading sequence and the camera daemon. Of course, the installation of drivers will necessary only for first time. The drivers can be smoothly uninstalled by a script uninstall_sbig_firmware.sh