The polar diagram plot description

The polar diagram shows the spacecraft corrected geomagnetic co-ordinates: co-latitude - local time.
The geomagnetic co-latitude in the range (10, 50) is shown with 10 step.
The geomagnetic local time meridians correspond to 6, 12 and 18 hours.

The different colours are used for each of the 4 spacecraft.
On the plot the SC names are shown by the corresponding colours.