Spectrum Analyser software

Spectrum Analyser software was developed for obtaining the emission spectra of the city from remote terrestrial sensing of the bright patch of sky associated with that city The method for decoding emission spectra by light-scattering spectrometry of a night sky is a unique approach that allows for

• systematic characterization of light-pollution sources over a specific territory, and,
• significant improvement of numerical prediction of skyglow changes we can expect at observatories in close surrounding of artificial sources of light.

Read in our MNRAS paper how the software helps to identify the night sky pollution sources.

How it works

1. Prepare the spectrum of the light dome in simple text-format (see the user-guide for the information about the structure of the data-file).
2. Run the GUI and open (File / Load Spectrum...) prepared file:
   
3. Fill-in Lambda Min and Lambda Max according to the range of the wavelenghts in measured spectrum.
4. Set Delta Lambda to the value of about 20 nm.
5. Select light sources to be included into the analysis.
6. Click the "Run" button.
7. Read the percentages found (down-right corner of the program) and the standard deviation (down-left corner of the program):
   
8. View the plot showing fitting results ("Plot INT") od showing mixed spectra ("Plot NON")
   
9. Change the light sources included into the analysis and find the best model (use standard deviation and/or Akaike’s Information Criterion.
10. Try another values of Delta Lambda to be sure that the results are stable.
11. The "Find Optimum"-button starts an automatic search for the best combination of light sources from that selected in "Participation"-section. The optimal subset of lights is found using Akaike's Information Criterion. It is a "brute-force" calculation, so be carrefful. The searching for the optimal combination among 6 light-types can take ca 1 minute, adding each next light-type doubles the required time.

Downloads

Version 1.1

Manual - more information about the prerequisities, structure of the data-files and instructions about compiling C/C++ parts in non-Windows environment.
Program including windows executables and C/C++ sources. Unzip into any folder and run SMOG.jar.
Program for the correction of spectra including windows executables and C/C++ sources. Unzip into any folder and run 'correctFileSpectrum.exe'-file.

Comments for Windows users

Program is distributed with windows-executables. Double-click the SMOG.jar file, or double click SMOG.cmd file. If you are not happy with the size of the program on the high-DPI screen, set Properties of SMOG.exe: Compatibility/Change high DPI settings/Override high DPI scaling behaviour. Scaling performed by: System. Then double-click SMOG.exe-program.
Please, install the GNUPlot viewer. Add GNUplot-path to the PATH variable of environment (typically C:\Program Files\gnuplot\bin) if not done automatically during the installation of GNUplot.

Comments for Linux-users

Compile C/C++ components in the "kernel"-folder according to the instructions in the manual. Install the GNUplot and the bitmap-viewer described in the manual.

Contact

František Kundracik
Department of Experimental Physics
Faculty of Mathematics, Physics and Informatics
Comenius University
Bratislava, Slovakia