APPENDIX 
117 MC 
DB BELOW 1 WATT 
117 MC 
OB BELOW 4 WATT. 
PERIODS OF SUPERSTANDARD 
M LAYERS ALOFT OMITTED 
80 60 40 
OB BELOW 1 WATT HIGH S BAND 
Ficure 10. Field strengths: 117 me and S band, July 
31 e August 17, 1944. 
20 
W748 
ZZ anna | 
200 500 
DUCT HEIGHT ane FEET 
Figure 11. Theoretical field strength versus duct 
height, bilinear index, first mode, 117 me. 
FIELD STRENGTH RELATIVE TO FREE SPACE VALUE IN DB 
w 0 
zz 
ae 
ty 
> 
Ey “20 
#% 
uy INEZ ee S=+1 (STANDARD) |__| 
gE -aql — Ss aa es) 
#o ere 
OUCT HEIGHT IN FEET 
Fiaurs 12. Theoretical field strength versus duct 
height, bilinear index, first mode, high S band. 
LS el ae 
ee 
-20 ° 20 40 60 80 100 120 
20 LOG ju} 
Ficure 13. Height-gain functions, standard and leaky 
first modes. (Ordinate: height. Abscissa: gain.) 
\ FOURTH MODE 
\ 
eal STANDARD FIRST MODE 
6 
lul 
Figure 14. Height-gain functions within a duct com- 
pared with standard first mode. (Ordinate: height. 
Abscissa: gain.) 
Altitude —» 
(0) 
B index Modified Relative To 4a/3 
Ficure 15. Modified index B. 
