TRANSMISSION EXPERIMENTS 33 
-O.1 
300 
REPRESENTATIVE 
| DETAILED 
MS SOUNDING ~|250 
200 
-10) } 
ke3 + — SEPT 16 
SEPT 16 1 
16015 baat ----SEPT 18 
+100 
100 
{ 50 
k ° 
| 270 280 2909 300 
(N-1) X 105—= 
100) 
10} won 
k" AS A FUNCTION OF TIME 
SEPT 16 AND 18 12:00- 18:00 O'CLOCK 
L0e=— — — a Om a ae 
—--~o- ---—-- ----- CAE S23 o-———___ Sons 
0.1 
12 13 la 15 16 \7 18 19 
TIME ‘IN HOURS ——= 
Ficure 11. Values of k as a measure of M or N gradient for part of period shown in Figure 10. 
the Canadian Wave Propagation Committee. They 
were started in the last year of the war and are still 
under way at the writing of the present report. 
These tests promise to throw light upon certain 
aspects of the propagation problem that are difficult 
to investigate elsewhere. The equipment is located 
on the prairies of western Canada. The transmission 
path is over terrain that is as near perfectly level 
ALTITUDE IN FEET X 10 
uo 
Ce 
i) 10 20 
ALTITUDE IN FEET X 10° 
as can be fourd. The ground is covered with short 
grass and is without trees or houses. The region forms 
part of a large flat area in which the atmosphere can 
be expected to be much more homogeneous than 
in more densely populated regions. Extensive meteoro- 
logical measurement by means of stationary installa- 
tions, captive balloons, and airplanes are being 
carried out simultaneously with the transmission 
5 
4 
3 Nov 9, 1943 _- 
2 XZESNOV I, 1943 
4 
300 320 340 360 380 400 420 440 460 480 500 
M=(n-4 +2) 10° 
\ i — NOVEMBER 11,.1943 
———— 
~ 
—~~. RS 
30 40 50 
RANGE IN NAUTICAL MILES 
Ficure 12 Signal strength at several elevations as function of distance. (Near San Diego.) 
