Software to calculate the Wtec index. Wtec is a regional TEC disturbance that is equal to the mean TEC variation (with periods less than the specified ones) amplitude for a single GPS/GLONASS site. One can make a multisite processing: the software calculates the corresponding index for each site. The maximum duration of the Wtec series is one year.


Just download and extract GetWTEC archive wherever you want (for Windows only).


Files and directories included in the software package

  • Executable file (GetWTEC.exe)
  • Configuration file (GetWTEC.dia)
  • Automatically created service directories (out, genout).


GetWTEC takes tec-suite output files as an input. These files must contain the following data:

  • tsn
  • el
  • az
  • tec.l1l2

For further information see tec-suite documentation.

Once you get tec-suite out files, you can

  • Edit GetWTEC.dia
  • Run GetWTEC.exe


e:\gps\dat\   	- datway (path to dat-files)
0  	  - crit_all =1 (processing of all sites)
LIST 	  - site (site name (if crit_all =0))
2016 	  - year
1  	  - daybeg (the first of the processed days)
366  	  - dayend (the last of the processed days)
300. 	  - hmax (height for calculating the coordinates of ionospheric points, km)
10. 	  - highper (window for removing slow variations, minutes)
15. 	  - gamcutoff (minimum elevation, degrees)
55  	  - prncutoff (the maximum number of satellites to process)
0  	  - GNSS_crit =0 (all satellites), =1 (GPS only), =2 (GLONASS only)
999 	  - GrossDir ("main" direction for processing, if =999 common file only)
4  	  - NofDirs (number of azimuth sectors (no more than 4))

Some parameters of GetWTEC.dia need explaining:

  • If crit_all = 1 all the sites found in the directory [datway][year][daybeg] are processed. If crit_all = 0 only the site specified in the site parameter is processed.
  • With the parameters GrossDir and NofDirs, one can specify additional output files with data in certain azimuth sectors relative to the processed station. NofDirs specifies the number of sectors (no more than 4). GrossDir sets the reference center direction for the first sector. If GrossDir = 999 only the common file will be output.


You can find an output of GetWTEC in the directory genout\YYYY. For each processed site, a file is created with the name SSSSDDD_DDD_YYYYF_PPmin.dat, where

  • SSSS (site name)
  • DDD_DDD (limits of the interval of processed days)
  • YYYY (year)
  • PP (window used to remove slow variations)
  • F (indicates that the file is common for all azimuths).

If the GrossDir parameter is set within the 0–360 range, in addition to the common file for the site, some more files (according to NofDirs value) will be created with data divided by azimuth sectors. The names of such files will look like SSSSDDD_DDD_YYYYAAA_PPmin.dat (AAA refer to center of azimuth sector).

All output files have the same structure. The first lines of an output file may look like this:

300	- height of F2-layer maximum
 10	- high filtering period, minutes
 15	- elevation cutoff
0	 =0 - GPS/GLONASS, =1 - GPS, =2 - GLONASS
999	- main direction
  4	- number of directions
tec_filt_aver - averaged through all prns filtered TEC variations
rms - root mean square of TEC averaging
Xaver, Yaver - average position of Ionospheric Pierce Point (km)
N_of_Sats - number of satellites

time_ut, tec_filt_aver, rms, Xaver, Yaver, N_of_Sats
   0.0000   0.0000   0.0000   67.570   14.884 11
   0.0083   0.0000   0.0000   68.378   15.365 11
   0.0167   0.0056   0.0055   69.187   15.841 11

The first 6 lines duplicate the values of the parameters hmax, highper, gamcutoff, GNSS_crit, GrossDir, and NofDirs from the file GetWTEC.dia.

The following 4 lines contain a description of the data columns:

  • time_ut refer to time count in UT hours from the beginning of the first day daybeg
  • tec_filt_aver is Wtec data
  • rms is data spread during averaging over satellites
  • Xaver, Yaver are deviations of the average ionospheric pierce point position from the site in kilometers
  • N_of_Sats is number of satellites to average.


You can report bugs or suggestions via email.


Should a scientific publication evolve from the conducted estimation from GetWTEC software, the authors are requested to include citation of following publications, where GetWTEC algorithm is described:

  • S.V. Voeykov, O.I. Berngardt, and N.V. Shestakov // Geomagnetism and Aeronomy, 2016, Vol. 56, No. 2, pp. 219–228. doi:10.1134/S0016793216020122.

Copyright © 2018 Sergey Voeykov.

Please note that free online access to the acquired data is arranged only for educational and non-commercial research purposes.