Ionosonde data in Japan

foF2 / fEs < 2MHz
2MHz < foF2 / fEs < 3MHz
3MHz < foF2 / fEs < 4MHz
4MHz < foF2 / fEs < 5MHz
5MHz < foF2 / fEs < 6MHz
6MHz < foF2 / fEs < 7MHz
7MHz < foF2 / fEs < 8MHz
8MHz < foF2 / fEs < 9MHz
9MHz < foF2 / fEs < 10MHz
10MHz < foF2 / fEs
No Frequency data