Instructions

• Select start date and number of days on 'Data period selection' panel on the left. The data period is used in determining base line values for each station by searching most quiet three hour interval during the whole data period. For each three hour interval (00-03, 01-04, ...) the sum of max-min values of X component of individual stations is computed. The most quiet three hour interval is the period where this sum is at minimum. The baseline value for each station is then set as the average value of X component during the most quiet 3h interval. (Note: to avoid some data issues, the number of days is actually fixed to be 1.)
• Select the plotting period on 'Plotting period selection' panel on the left. Plotting period is a subinterval of Data period. By default it is set as equal to Data period. Plotting period is used in plotting the electrojet indicator grams.
• Select stations on 'Station selection' panel on the left. By default no stations are selected. User may select/unselect individual station by clicking on station circles. Some predefined sets are also available. After selecting the stations click the 'OK' button.
• Click 'Generate grams' button to compute electrojet indicators and display grams. The generation of indicator grams takes a few seconds after which the images will be shown here.

More buttons

• 'Station statistics' graph will show the contribution of individual stations to IU and IL indicators.
• X, Y and Z grams are station stack plots of each three magnetic components. These plots are generated at the same time as the electrojet indicator plots but their generation takes much longer time so the buttons become active only after the images are ready.
• Indicators data file contains the computed electrojet indicators. The header section lists the stations used in the analysis, their contributions to IU and IL indicators and adopted baseline values. The data is in the form:
  
  

  YYYY MM DD HH MI SS        IL      IU      IE     la_IL lo_IL la_IU lo_IU
  2018 12 01 00 01 30      -12.3    16.5    28.8    69.30 16.03 78.92 11.95
  						

  where 'la_IL' and 'lo_IL' are the latitude and longitude of the station which contributes the IL indicator and 'la_IU' and 'lo_IU' those for IU indicator.
• The original data files (in IAGA and text format) may downloaded by clicking corresponding buttons in 'Data files' panel.