Understanding propagation numbers
How To Read Propagation Numbers The A index [ LOW is GOOD ] 1 to 6 is BEST 7 to 9 is OK 11 or more is BAD Represents the overall geomagnetic condition of the ionosphere (“Ap” if averaged from the Kp-Index) (an average of the eight 3-hour K-Indices) (‘A’ referring to amplitude) over a