genfam.f
Re-written 3.June.93 by Greg Hand because previous version wa
really incorrect. It made an attempt to limit Sigma Fam (DMS)
to a 10 MHz frequency, but the indicies I and J became
confused, and the result was not correct. Ironically,
Sigma Fam was the only result that was computed correctly.
DUA, DLA, DUS, DLS were all incorrect. This current
version should limit DMS to 10 MHz and the others to 20 MHz
because their curves end at 20 MHz. Unfortunately, this error
has probably existed since time began, and it may take a
while for this corrected version to propagate into all versio
that exist. The magnitude of the errors in DUA, DLA, DUS, DLS
could approach +/- 4dB at 20MHz. However, for use in
propagation prediction programs such as IONCAP, these errors
are almost unnoticable because Atmospheric Noise is not
the driving force at HF frequencies.
INPUTs:
Y2 = latitude of point of interest
only cares if + or - to flip Northern/Southern Hemis
IBLK = time block of interest (local time 1=0000-0400)
FREQ = Frequency in MHz
Z = 1 MHz Fam value
OUTPUTs:
FA = Frequency variation of Fam
DUA = Du = ratio of upper decile to median value (Fam)
DLA = Dl = ratio of median value (Fam) to lower decile
DMS = Sigma Fam = standard deviation of values of Fam
DUS = Sigma Du = standard deviation of values of Du
DLS = Sigma Dl = standard deviation of values of Dl
GENFAM CALCULATES THE FREQUENCY DEPENDENCE OF THE ATMOSPHERIC
NOISE AND GETS DECILES AND PREDICTION ERRORS FROM TABLES |