What is FROGS?
FROGS stands for Fancy Reconstruction by Optimization over Gamma ray
Simulations. It is an implementation of the image template analysis
for arrays of Cherenkof telescopes. Relevant references are
Le Bohec et al., 1998
and de Naurois and Rolland, 2011.
The likelihood is calculated as by de Naurois and Rolland but the model is
tabulated and obtained from simulations of a large number of gamma ray
showers instead of being obtained from a semi analytical model. FROGS
was developped in the context of the
and analysis programs and of
VERITAS but it is specific
to neither. It is written in plain c but requires a c++ compiler and the
GSL libraries and the Cherenkov
telescope data to be stored in some specific structures in a function to
be written by the user. There is no actual documentation but the comments
and example provided in the program files should be sufficient.
The FROGS functions are currently maintained by
Stephane Vincent (firstname.lastname@example.org) and
Stephan LeBohec (email@example.com).
Anyone is welcome to download the FROGS files to use them for any chosen purpose under the
terms specified in the GNU General Public License
. An explicit reference
to the package and this distribution page should be given in publication
of studies using the FROGS functions. Comments and suggestions can be made
by writing directly to the authors
Stephane Vincent (firstname.lastname@example.org)
Stephan LeBohec (email@example.com)
- FROGS1.02 was improved in the way the template file is selected. There is now a file named frogs_template_file_list which contain the template files to be used with for each a minimal and maximal elevation for the use. Each time the current event elevation is outside the range of applicability of the current template the file is read and the new template loaded accordingly unless none can be found and an error message is then generated. The name of the file holding template file names and elevation ranges is defined in frogs.h.
- FROGS1.01 is the second release. No fundamental changes but different functions were moved to different files so as to decouple analysis packages specific elements from FROGS specific functions to make updates easier.
- FROGS1.00 is the first release. As subsequent versions are released, we will provide a log of the modifications.
- Current version of all you need
- Template files provided with the first release for elevations:
These template files were produced using Kascade and Cherenk from the
GrISU(tah) software package.
The average shower images were convolved with a disk of radius 0.085 degree.
The scripts and programs used to prepare template files will be made
available shortly and can be obtained upon request.
- FROGStemplatecreation.tar includes two Perl scripts utilizing Kascade and Cherenk to streamline production of FROGS templates WITH a readme file. Questions regarding their use can be directed to Spencer Hatch (spencerhatchATmail.weber.edu)
- FROGStemplateviewer.tar is a small C++ file which both produces a ROOT-compatible version of a FROGS template, and provides two macros for viewing a template as well as comparing two templates. Spencer Hatch is responsible for this tool as well.
Comments regarding the web page itself should be sent to Stephan LeBohec (lebohecATphysics.utah.edu)