28 TECHNICAL SURVEY 
= HIGH AND VARIABLE == 
= AUGUST 17, 1944 
= S, BAND 
HIGH RECEIVER 
DB BELOW | WATT 
f= |=) FIRST [TYPE : | 
= — ——— 
Pe =| = S==s— Sac ATS nT AD 
thy ES 
s&s = HIGH AND STEADY 
SEPTEMBER 24, 1944 
= X BAND 
HIGH RECEIVER 
es SS eo : 
OB BELOW | WATT 
= STANDARD AND STEADY 
SEPTEMBER 18, 1944 
X BAND 
HIGH RECEIVER 
OB BELOW | WATT 
= STANDARD WITH MARKED SCINTILLATION 
= JULY 7-8, 1944 
X BAND 
HIGH RECEIVER 
lee 
OB BELOW | WATT 
X BAND 
HIGH RECEIVER 
=== eee 
DB BELOW | WATT 
Ficure 3. Microwave signal types Sq and X band, Massachusetts Bay. 
type may remain constant on one frequency and 
change on the other. Steady signal is most frequent 
at 256 cm, but the other types shown also occur 
fairly often. Variations of 30 to 40 db overall take 
place, and the variations may be fast or slow. 
A statistical study of the frequency of occurrence 
of various signals reveals some rather interesting 
features. Table 1 shows the frequency of occurrence 
of above standard, standard, and below standard 
types on the § aad X bands during three typical 
weeks in the summer of 1944. In these statistics the 
range of the standard signal was taken as +5 db 
for the S band and +10 db for the X bard. The 
behavior of the K-band signal is quite similar to 
that of the other two. 
As the season progressed into the fall, standard 
