<s>
Ultra	B-Algorithm
low	I-Algorithm
frequency	I-Algorithm
(	O
ULF	O
)	O
is	O
the	O
ITU	O
designation	O
for	O
the	O
frequency	O
range	O
of	O
electromagnetic	O
waves	O
between	O
300	O
hertz	O
and	O
3	O
kilohertz	O
,	O
corresponding	O
to	O
wavelengths	O
between	O
1,000	O
to	O
100	O
km	O
.	O
</s>
<s>
Using	O
weak	O
signal	O
reception	O
methods	O
with	O
PC-based	O
DSP	B-General_Concept
filtering	O
with	O
extremely	O
narrow	O
bandwidths	O
,	O
it	O
is	O
possible	O
to	O
receive	O
signals	O
at	O
a	O
range	O
of	O
a	O
few	O
kilometers	O
with	O
a	O
transmitting	O
power	O
of	O
10100W	O
and	O
electrode	O
spacing	O
of	O
around	O
1050m	O
.	O
</s>
