242 RADIO WAVE PROPAGATION EXPERIMENTS 
TasLe 1. Radar-weather tabulation, March 5-6. 
Time (EWT) 
19 20 21 22 23 00 01 02 03 04 05 06 07 
SCR-584 ground range* (S-band) 1 2 2 1 1 1 2 2 2 1 1 1 il 
SCR-588 ground range (P-band) ie Be 1 aye te 2 2 3 2 1 1 1 1 
M-curve typet tS) D D 06 Se L G L L Ss Ta Ss Ss 
Duct height (ft) .. 200 200 Bb .. 3870 350 380 400 -. 450 
: 14 14 ae as 14 14 14 11 ae 6 as iS 
ane wind (mph) 5 4 4 O0 o0 0 1 3 5 6 6 5 7 
*Ground range: 1, standard; 2, 3, 4, degrees of superrefraction. 
{M-curve types: 8, standard; D, duct (simple surface trapping); G, ground-based S curve; L, elevated S curve; T,, transitional aloft. 
mately constant from midnight to 0200, after which 
the curve gradually appreached standard. 
Table 1 summarizes the weather and radar varia- 
tions. It should be pointed out that the antenna height 
for the P-band SCR-588 was 140 ft above the sound- 
ing site, for the S-band SCR-584 the same height as 
the sounding site. Thus at 2100 we have a 200-ft sur- 
face duct trapping the SCR-584, but not trapping the 
SCR-588 (duct height 60 ft above the antenna), while 
from midnight to 0300 an elevated duct of the order 
of 380 ft traps both sets (duct height some 250 ft 
above the SCR-588 antenna). By 0400 the winds 
became strong enough to wipe out the stratified layers 
and mix the air, giving standard conditions. At 0500 
a trace of a transitional condition aloft appears in the 
sounding but is not sufficient to extend the range. 
During the months of January and February data 
were collected on S-band V beam at Tomato Hill 
during 47 days. Of these days’ observations 37 per cent 
showed nonstandard conditions. During the same pe- 
riod the SCR-271 at Crystal River showed at least 
slight increases in ranges on 72 per cent of the days’ 
2200 EWT 
Q100 EWT 0300 EWT 
600 
bi 400 
we 
= 
e 
=x 
0400 EWT 3 200 
=x 
Ficure 6. SCR-584, Winter Garden, night of March 5 
to 6, 1945. Superstandard propagation occurs to the 
northwest at 0100 and 0300 EWT. At 0400 EWT the 9 
FS 5 aLsp 360 365 370 355 360 365 370 355 3 370 
pattern is again standard. The line on the PPI indicates - 350 ee EWT 0008 EWT ei Bee 
true north. 
went from standard to above standard and returned to 
standard. After midnight ranges built up rapidly and 
held until after 0300, when they began a gradual re- 
turn to standard, reaching that condition shortly after 
0400. 
The M curve measured at 1900 was standard, fol- 
lowed by those illustrated in Figure 7. Unfortunately, 
no soundings were taken between 2035 and 0008, and 
consequently the evolution of the elevated S from the 
surface duct is not shown. We know that the surface 
HEIGHT IN FEET 
C) 
; ale 355 360 365 370 355 360 365 370 360 365 370 375 380 
wind decreased from 4 mph at 2000 to calm at mid SSAA SSRlewT BaGoIENn 
night, while the 1,000-ft wind increased from 10 to Ficure 7. M curves for night of March 5 to 6, 1945, 
20 mph. The duct height and AM value were approxi- based on soundings at Leesburg AAF. 
