TELKOM
NIKA Indonesia
n
Journal of
Electrical En
gineering
Vol.12, No.4, April 201
4, pp. 3168 ~ 3
1
7
6
DOI: http://dx.doi.org/10.11591/telkomni
ka.v12i4.4787
3168
Re
cei
v
ed Au
gust 28, 20
13
; Revi
sed
No
vem
ber 2
1
, 2013; Accepte
d
De
cem
ber
9, 2013
Sea Surface Reflection and Power Attenuation Analysis
of Radio Wave in UHF Satellite Communications
Yuanming Ding*
1
, Jingjing Sun
2
, Xue
Wang
3
1,2
Key
Lab of C
o
mmunic
a
tio
n
and N
e
t
w
ork, Dali
an U
n
ivers
i
t
y
, Dali
an, Li
ao
nin
g
11
662
2, Chin
a
3
School of Infor
m
ation En
gi
ne
erin
g, Dali
an
U
n
iversit
y
, Da
lia
n, Liao
ni
ng 11
662
2, Chi
n
a
*Corres
p
o
ndi
n
g
author, e-ma
i
l
: ding
yu
a
n
min
g
@dl
u
.ed
u
.cn
1
, xin
x
i
n
ra
nsun
@16
3
.com
2
,
w
angx
ue@dlu.
edu.cn
3
A
b
st
r
a
ct
Ultra Hi
gh F
r
equ
ency (
UHF
) ban
d is
incr
easi
ngly w
i
del
y used
in
mili
tary mariti
me
satelli
t
e
communic
a
tio
n
s
due to its go
od co
mmu
n
icat
ion p
e
rfor
manc
e. Electromag
n
e
tic w
a
ve emitt
ed by satel
lite i
s
reflected
w
hen
reach
i
ng
the s
ea s
u
rfac
e, a
n
d
multi
path
fadi
ng is
very s
e
rio
u
s w
h
ich c
aus
es interf
erenc
e
o
n
the rece
ived s
i
gna
l, espec
ia
ll
y w
hen satel
lit
e el
evatio
n
a
n
g
le is
low
.
In this pa
per, the U
H
F
ban
d multi
path
effects of sea surface
w
e
re studie
d
foll
ow
in
g the ge
nera
l
princi
pl
es of mode
lin
g in
mu
ltipath effects. T
h
e
nu
meric
a
l
si
mu
latio
n
w
a
s
ma
de
base
d
on
R
a
ylei
gh
cr
iteri
o
n a
nd t
he
ju
dg
me
nt b
a
sis w
a
s obta
i
ne
d w
h
i
c
h
deter
mi
nes w
hether the spec
ula refl
ected c
o
mpo
nent or
diffuse reflec
te
d compo
nent
do
mi
nates in t
h
e
reflected
w
a
ve
, and t
hen
the
reflectio
n
c
o
e
fficient of
s
ea surface
i
n
different pol
ari
z
a
t
i
on mo
des
w
e
r
e
calcul
ated. F
i
n
a
lly, th
e p
o
w
e
r
attenuati
o
n
of r
e
flected
w
a
ve
r
e
lativ
e
to
dir
e
ct w
a
ve for
differ
ent w
i
nd
sp
eed
s
w
e
re simulate
d an
d an
aly
z
e
d
. Nu
meric
a
l s
i
mulati
on re
s
u
l
t
s show
that the great
er the
w
i
nd spe
ed is,
the
greater
the
po
w
e
r attenu
atio
n of r
e
flecte
d
w
a
ve w
ill
bec
o
m
e
a
nd th
e
mo
re seri
ous
mult
ipath
fadi
ng
w
i
l
l
b
e
.
In additi
on, diff
use reflecti
on a
ttenuatio
n is more seri
ous tha
n
specu
l
ar refl
ection.
Ke
y
w
ords
: se
a surface
mul
t
ipath effects, sea surfac
e
reflectio
n
, pow
er attenu
atio
n, UHF
, mar
i
ti
me
satellit
e co
mmunic
a
tions
Copy
right
©
2014 In
stitu
t
e o
f
Ad
van
ced
En
g
i
n
eerin
g and
Scien
ce. All
rig
h
t
s reser
ve
d
.
1. Introduc
tion
SATCOM
has been very widely
us
ed in the
civilian and milit
ary fields due to its
advantag
es,
su
ch a
s
a
wi
de cove
re
d range, radio
f
eature
s
, flexible networkin
g, comm
unication
without geo
graphi
cal re
stri
ction
s
,
comm
unication co
st
s ind
epe
nde
nt of di
stan
ce
, etc. In
satell
ite
comm
uni
cati
on, the l
o
wer ban
d of
UHF (frequ
en
cy
r
a
n
g
e
o
f
300
MHz
to 3
000
MHz
)
is us
ua
ll
y
use
d
and VHF band (fre
q
uen
cy rang
e of 30MHz
to 300M
Hz) is
occa
sion
ally use
d
. UHF h
a
s
many uni
que
advantag
es i
n
military a
p
p
lication
s
[1],
su
ch a
s
th
e strong
pen
etra
tion sig
nal a
n
d
pra
c
tical te
rminal, ca
n
achi
eve glo
b
a
l rea
c
h
an
d broad
ca
sting net
work,
use
r
a
c
ce
ss is
guarantee
d a
nd so o
n
.
The multip
ath pro
pag
atio
n co
mpon
ent
due to
sea
su
rface refl
ection i
s
diff
icult to
sup
p
re
ss wh
en
the elect
r
oma
gneti
c
wave
e
m
i
tted by satellite re
ache
s the sea
su
rface,
esp
e
ci
ally in
the region
wi
th lower sate
llite
elevation
angl
e
whi
c
h
mea
n
s 0°-2
0° h
e
re a
nd t
he
sea
su
rfa
c
e
multipath fad
i
ng is ve
ry o
b
vious.
Un
der
s
t
a
n
d
i
n
g
th
e c
h
ar
ac
te
r
i
s
t
ic
s
o
f
mu
ltip
ath
fading chan
n
e
l of sea
su
rface
and m
odelin
g of it
are very ne
cessary d
u
rin
g
the de
sign
of
comm
uni
cati
on
system
s.
As ea
rly a
s
t
he 1
950
s,
m
u
ch
attention
ha
s b
een
gi
ven to multip
ath
probl
em, and
a large nu
mber of stu
d
i
es were
m
a
de in the ch
ara
c
teri
stics
of sea surfa
c
e
electroma
gne
tic dispersio
n
, and multip
ath refle
c
ti
on m
odel
s are e
s
tablished. Lite
rature [2] ma
de
a re
sea
r
ch o
n
the cha
r
a
c
teristics of L
-
ban
d mu
ltip
ath fading d
ue to sea
surface refle
c
t
i
on.
Literatu
re [3]
studi
ed th
e
se
a
surfa
c
e
multipath
m
odel
of mete
r ba
nd. In lit
eratu
r
e [4],
sea
surfa
c
e
multi
path cha
r
a
c
te
ristics
of C-b
and we
re
me
asu
r
ed
an
d t
he te
st results
were a
naly
z
ed.
Literatu
re [5]
simulate
d the
process
of
multipath
effe
ct in th
e e
n
vironment
of
cal
m
an
d dyn
a
m
ic
lake surf
a
c
e.
Curre
n
tly, fe
w re
sea
r
che
s
have been
made on
UHF band ele
c
tromagn
etic reflection of
sea
su
rfa
c
e
and it is difficult to find
complete a
nd
accurate te
st data a
s
a
re
sult of the
co
stly
spe
nd on a
c
tual mea
s
ure
m
ent on the sea. The
r
efo
r
e, in this pap
er, the UHF
band multip
a
t
h
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Sea Surface Refle
c
tion an
d Powe
r Attenuation
Anal
ysis of Radio
Wa
ve…
(Yua
nm
ing Ding
)
3169
effects of
sea
surfa
c
e
are a
nalyze
d
, and
sea
su
rf
ace reflection
co
efficient an
d po
wer
attenuati
o
n
of reflected
wave are calcu
l
ated.
2. Multipath
Fading and
Sea Wea
Hei
ght
In maritime
satellite co
mm
unication
s, p
a
rtial el
ectro
m
agneti
c
sig
nal tra
n
smitted from
the
satellite gets
to the receivi
ng antenn
a directly whi
c
h i
s
called the
direct wave. The other parti
a
l
rea
c
he
s the receivin
g ante
nna by refle
c
tion from
sea
surfa
c
e
whi
c
h
is calle
d the reflecte
d wav
e
.
Then b
o
th en
ter the re
ceiv
er in the
way of vector su
perp
o
sitio
n
. Becau
s
e th
e path dista
n
ce
s of
each ele
c
tro
m
agneti
c
wa
ve are
differe
nt, their a
rrivi
ng time a
nd
pha
se a
r
e
different. A plu
r
ality
of signal
s
su
perim
po
se at
the receiver which s
upe
rpose in-pha
se at times a
nd in reve
rse
on
occa
sion. As
a result, the amplitude
s of
receiv
e
d
sig
nal ch
ang
e d
r
amati
c
ally, whi
c
h produ
ce a
decli
ne. Sign
al attenuatio
n
cau
s
e
d
by m
u
ltipath is
call
ed multipath f
ading. Th
e m
u
ltipath effect
s
model of se
a surfa
c
e i
s
sh
own in Fig
u
re
1.
2
L
t
1
L
Figure 1. Sea Surface M
u
ltipath Effects
Model
In Figure 1,
h
is the verti
c
al
distan
ce from
phase c
ente
r
of the anten
na to the refl
ective
surf
a
c
e,
t
is satellite elevation angl
e. In this mod
e
l, there a
r
e t
w
o path
s
fro
m
satellite to
receiving
a
n
tenna whi
c
h a
r
e
the dire
ct wave
a
nd refl
ected wave. The satellite
i
s
very
far
a
w
a
y
from the refle
c
tive su
rface comp
ared wit
h
the ant
enn
a, so it is con
s
ide
r
ed that
signal
s rea
c
hi
ng
the antenna and the
sea surface from same
satellite are parallel [5].
Oce
an wave
is the re
cipro
c
ating motio
n
phenom
eno
n of sea wat
e
r und
er sea
bree
ze.
Different wi
n
d
spee
ds
correspon
ds to different
wav
e
heights. F
o
r non
-calm sea
surfa
c
e,
the
irre
gula
r
signi
ficant wave h
e
ight
i
s
u
s
u
a
l
l
y
indicated a
s
3
/
1
H
, which i
s
al
so
kn
own a
s
the
one
third g
r
eat wave. It is got by arrangin
g
the wave
height
s a
cco
rding to th
eir sizes
and t
h
e
n
cal
c
ulatin
g th
e ave
r
ag
e h
e
ight of
1/3
wave
s in
fro
n
t of the
qu
e
ue. Studie
s
have
sho
w
n
that
signifi
cant
wave heig
h
t can reflect the
relatio
n
ship
s of ocean
wave growi
ng.
Taki
ng the
fully
gro
w
ing o
c
e
an wave a
s
the backg
ro
und, Formul
a (1) i
s
u
s
e
d
to descri
b
e the relatio
n
shi
p
betwe
en wi
nd
spee
d and
si
gnifica
nt wav
e
height [6].
2
3
/
1
0214
.
0
U
H
(1)
Whe
r
e,
3
1
H
is th
e si
gnifica
nt
wave
height,
U
is
wind
spe
ed o
n
the
se
a. Mean
squ
a
re
wave
height
h
refe
rs to the m
e
a
n
squa
re
roo
t
value of
wave heig
h
t o
n
o
c
ean
surf
ace,
and it
s
relations
h
ip with s
i
gnificant wave height is
as
follows
:
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3168 – 3
176
3170
h
H
4
3
1
(2)
Table
1 li
sts t
he value
s
of
signifi
cant
wa
ve height
and
mean
squa
re wave hei
gh
t unde
r
different win
d
spee
ds.
Table 1. Signi
ficant Wave
Heig
ht and M
ean Squa
re
Wave Height
Wind speed U(m
/
s)
Significant w
a
ve
height
3
1
H
(m)
Mean square
w
a
ve h
e
ight
h
(m)
1 0.0214
0.00535
3 0.1926
0.04815
5 0.5350
0.13375
7 1.0486
0.26215
9 1.7334
0.43335
11 2.5894
0.64735
13 3.6166
0.90415
15 4.815
1.20375
3. Sea Surfa
ce Re
flec
tion
3.1. Ra
y
l
eigh
Criterion
Surface can
be divided
into smo
o
th
surfa
c
e
and
roug
h surfa
c
e a
c
cording
to the
roug
hne
ss de
gree of refle
c
t
i
ve surfa
c
e. On a smo
o
th
flat surface, the su
rf
ace sp
ecul
ar refle
c
ti
on
is domin
ant. On a ro
ugh
surface, it prod
uce
s
diffuse reflection eith
er. Wh
en the
undul
ating wave
height difference sati
sfie
s Raylei
gh crite
r
ion d
e
scrib
ed a
s
in
Formula
(3
), it is gene
rally
c
o
ns
ide
r
ed
th
e
s
e
a
s
u
r
f
ac
e is
s
m
oo
th
a
n
d prod
uces
specular
refle
c
tion only [3].
t
h
sin
8
1
(3)
Whe
r
e,
h
is the mean sq
uare wave heig
h
t,
is the wave
length of the incid
ent wave
,
t
is the
satellite elev
ation angl
e. Literatu
re [7]
gives t
he el
e
v
ation angle
cal
c
ulatio
n formula
of sate
llite
receiving ant
enna.
L
G
R
R
L
G
E
WG
DP
2
2
cos
cos
1
cos
cos
arctan
(4)
Whe
r
e,
E
is ele
v
ation angle,
L
is the latitude
of the
receiv
ing point at sea,
G
is the longitude
difference between receiv
ing
point and satellite,
DP
R
is th
e radiu
s
of th
e ea
rth
re
cei
v
ing poi
nt,
WG
R
is synchronous orbit radi
us of satellite.
As i
s
shown
in Figure 2,
absci
ssa i
s
satellit
e elevat
ion angle, y
-
ax
is i
s
m
ean square
wave hei
ght
and two
cu
rves a
r
e Raylei
gh cu
rve
s
wh
en freq
uen
cie
s
are 240
MHz and
320M
Hz,
respe
c
tively. It is can
be
see
n
that wh
en freq
uen
cy
is 24
0MHz
and
wind
sp
eed i
s
le
ss t
han
7m/s, the se
a su
rface is regarded
smo
o
th. When
f
r
eque
ncy is
3
20MHz a
nd satellite elevation
angle
14
t
, the sea surfa
c
e
can
not be rega
rded sm
ooth
and specula
r
reflectio
n
mo
del can
not be u
s
e
d
a
s
the
sea
su
rf
ace
multipath
model.
So, concl
u
si
on can
be
got
that whether
the se
a
surfa
c
e i
s
sm
ooth or not is
related
with the
wind
spe
e
d
on sea, ele
c
trom
agn
etic
wave freq
uen
cy
and satellite elevation an
g
l
e.
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Sea Surface Refle
c
tion an
d Powe
r Attenuation
Anal
ysis of Radio
Wa
ve…
(Yua
nm
ing Ding
)
3171
Figure 2. Ray
l
eigh Curve
s
and Satellite Elevation Angle
3.2. Specula
r Refle
c
tion
Coe
fficien
t
For th
e id
ea
l refle
c
ting
surface th
at i
s
com
p
letely
sm
ooth, th
e surfa
c
e
re
flection
coeffici
ent
is
equal
with
Fresn
e
l reflecti
on
coeffici
ent
s
0
, namely
0
. Fresn
e
l reflecti
on
coeffici
ent is ascertai
ned
by
electro
m
agneti
c
wa
ve freque
ncy
,
polari
z
ation
mode, sate
llite
elevation an
g
l
e and surfa
c
e type [8]. Th
e
vertical pol
arization is gi
ven by:
t
t
t
t
2
2
0
cos
sin
cos
sin
(5)
Hori
zo
ntal pol
arization is gi
ven by:
t
t
t
t
2
2
0
cos
sin
cos
sin
(6)
Whe
r
e,
is
the water
c
o
mplex permittivity. The c
o
mp
lex permittivity values
are related to the
type of su
rfa
c
e. In te
rms of the ele
c
t
r
oma
gneti
c
wave
frequ
e
n
cie
s
we stu
d
ied,
the sp
ecific
cal
c
ulatio
n expre
ssi
on
s of water
com
p
le
x permittivity
are a
s
follows [9]
:
'
'
'
i
(
7
)
Whe
r
e,
2
'
2
1
f
ir
s
ir
f
f
f
s
ir
s
0
2
'
'
2
2
1
2
Whe
r
e,
f
is fre
quen
cy of el
ectro
m
ag
neti
c
wave
and
unit is Hz,
0
is the permittivity of fre
e
spa
c
e an
d
m
/
F
10
854
.
8
12
0
,
ir
is the sea wate
r diele
c
tric p
e
r
mittivity and
9
.
4
ir
.
is
the relaxation
time of sea water,
s
and
s
are the ionic
co
ndu
ctivity
and the static p
e
rmittivity
of s
ea water,
respec
tively.
s
,
and
s
can be
calcul
ated by the followi
ng
Fomula
rs:
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3168 – 3
176
3172
a
T
s
)
(
3
4
2
2
1
10
491
.
2
10
276
.
1
10
949
.
1
134
.
87
)
(
T
T
T
T
3
7
2
5
3
5
10
232
.
4
10
21
.
3
10
656
.
3
10
613
.
1
0
.
1
S
S
S
TS
a
b
T
)
(
3
16
2
14
12
10
10
096
.
5
10
938
.
6
10
824
.
3
10
111
.
1
2
1
)
(
T
T
T
T
3
8
2
6
4
5
10
105
.
1
10
760
.
7
10
638
.
7
10
828
.
2
0
.
1
S
S
S
TS
b
e
S
s
,
25
3
7
2
5
3
10
282
.
1
10
093
.
2
10
4619
.
1
18252
.
0
,
25
S
S
S
S
S
T
25
2
8
7
5
2
-6
4
2
10
551
.
2
10
551
.
2
10
849
.
1
10
2.464
10
266
.
1
10
033
.
2
S
In Formula
s
above, wate
r temperatu
r
e
T
is taken a
s
28
℃
and th
e global ave
r
age valu
e of
salinity
S
is
%
254
.
3
.
Fre
s
nel
form
ula i
s
used t
o
calculate
the
re
flec
tion c
o
effic
i
ent
of c
o
mpletely
s
m
ooth
interface. Ho
wever,
in a
c
t
ual
situation,
the s
ea su
rfa
c
e ca
n
n
o
t
be
ab
solutely smooth with some
fluctuation. If the refle
c
tive surfa
c
e i
s
wit
h
ce
rtai
n ro
ug
hne
ss, but i
s
relatively flat,
in other
word
s,
it satisfies the
Rayleigh
Crit
erion, then th
e spe
c
ul
a refl
ection
coeffici
ent can b
e
expre
s
sed a
s
:
s
0
(
8
)
Whe
r
e,
s
is the
sp
ecular scattering fa
cto
r
, whi
c
h
de
n
o
tes th
at the
rou
ghn
ess
of refle
c
tive
surfa
c
e m
a
ke
s the amplitu
de of spe
c
ul
a
r
refle
c
tion attenuate a
nd its value
s
are
as follo
ws [10
]
:
1
.
0
2
2
1
812537
.
0
1
.
0
0
2
2
exp
2
2
2
s
(9)
is the rou
ghn
ess facto
r
of rough
surfa
c
e
whi
c
h is d
e
scribed a
s
follo
ws:
t
h
sin
(10)
Assu
med
tha
t
the in
ciden
t wave frequ
ency i
s
320
MHz an
d
wi
nd
spe
ed i
s
7m/s, in
vertical a
nd
hori
z
ontal
po
larization m
o
des, the
Fre
s
nel
refle
c
tio
n
co
efficient
s an
d spe
c
u
l
a
reflectio
n
coe
fficients
with t
he introdu
ctio
n of
spe
c
ul
ar
scattering
fa
ctor of th
e
sea
are
comp
are
d
in Figure 3.
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TELKOM
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Sea Surface Refle
c
tion an
d Powe
r Attenuation
Anal
ysis of Radio
Wa
ve…
(Yua
nm
ing Ding
)
3173
(a) Ve
rtical p
o
lari
zation
(b) Hori
zo
ntal
polari
z
ation
Figure 3. Fre
s
nel a
nd Spe
c
ula
r
Refle
c
ti
on Co
efficient
in Different Polari
zation M
ode
s
As ca
n be se
en from Fig
u
re 3, the ampl
itude of
Fre
s
nel refle
c
tion
coeffici
ent in vertical
polari
z
atio
n
mode i
s
smal
ler
comp
ared
with in
ho
rizontal pol
ari
z
a
t
ion mod
e
. T
he latter is
al
most
a
s
lar
g
e
as
1. C
o
mp
ar
e
d
w
i
th
F
r
es
ne
l r
e
fle
c
tion
coe
fficient of ide
a
l interfa
c
e, the amplitud
e
of
spe
c
ul
ar
refl
ection
coefficient is some
what
a
ttenua
ted
with
introdu
ction of spe
c
ul
ar sca
tter
factor. Sp
ecu
l
ar
scatter fa
ctor ha
s
a g
r
eater im
pa
ct
on h
o
ri
zontal
pola
r
i
z
ation
mode
than
o
n
vertical pol
ari
z
ation mo
de.
3.3. Diffu
se
Refle
c
tion F
actor
Whe
n
the se
a surfa
c
e i
s
so ro
ugh tha
t
Ra
yleigh criterion can n
o
t be met, specular
reflectio
n
red
u
ce
s and diff
use reflectio
n
incre
a
ses
wi
th the incre
a
s
e of rou
ghn
ess. The po
wer
reflecte
d to
a
n
tenna
from
sea
surfa
c
e
i
s
m
a
inly
cont
ributed
by
diffuse
refle
c
tio
n
. It occu
rs
on
area
mu
ch
l
a
rge
r
th
an t
he first F
r
e
s
nel
zon
e
wh
ose
ph
ase i
s
n
o
t related
and
am
plitu
d
e
fluctuation
is
large.
Ge
om
etrical
o
p
tics
theory
do
se
not satisfy dif
f
use
refle
c
tio
n
which m
e
a
n
s
that the in
cid
ence a
ngle i
s
n
o
t equ
al t
o
refl
e
c
tion
a
ngle
and
una
ble to e
s
tabli
s
h
geom
etri
cal
relation
shi
p
with the direct
wave. The dif
f
use refl
ectio
n
coeffici
ent of rough
su
rface i
s
define
d
by
the followin
g
Formul
a (1
1):
d
0
(11)
Whe
r
e,
d
is diffuse
reflection
factor whi
c
h is
a co
mpl
e
x function
of sa
tellite elevation angle
t
,
mean
squa
re
wave
hei
gh
t
h
, wavelen
g
th ele
c
tromag
netic
wave
. The
app
roxi
mations of
diffuse refle
c
t
i
on factor a
r
e
got th
roug
h theoretical
re
search [11]:
5
.
0
,
025
.
0
2
5
.
0
1
.
0
,
858
.
0
454
.
0
2
1
.
0
0
68
.
3
2
0
0
0
，
d
(12)
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TELKOM
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Vol. 12, No. 4, April 2014: 3168 – 3
176
3174
(a) Ve
rtical p
o
lari
zation
(b) Hori
zo
ntal
polari
z
ation
Figure 4. Diffus
e
Reflec
tion Fac
t
or
in Different Po
lari
zation Mo
de
s
Figure 4 sho
w
s the
relatio
n
cu
rve of diffuse
refle
c
tion
factor an
d sa
tellite elevation angle
of different el
ectro
m
ag
neti
c
wave freq
u
enci
e
s i
n
se
a
state 4. It ca
n be
seen f
r
o
m
the sim
u
lat
i
on
,
with the satell
ite elevation angle in
crea
ses, the
diffuse refle
c
tion coefficient am
plitude
s incre
a
se
within a
ce
rta
i
n elevation
a
nd be
gin
s
to
decrea
s
e
afte
r re
aching
a l
i
mit value. Besid
e
s, it is n
o
t
alway
s
true that the highe
r the frequen
cy is, the la
rge
r
the diffuse reflection fa
ctor be
com
e
s.
4. Analy
ses
on Rec
e
iv
ed
Po
w
e
r
In
maritime satellite com
m
unication
s busi
n
e
ss,
th
e
re
ceived signal
is gen
erally
the
synthe
sis of
three
comp
onent
s, nam
ely dire
ct wave, spe
c
ula
reflecte
d wave and diff
use
reflecte
d wa
ve. If the reflective wave
come
s from
the first Fre
s
nel
zone m
eeting Raylei
gh
crite
r
ion,
whi
c
h d
enote
s
that sea
su
rface i
s
relati
vely smooth,
the specul
ar reflectio
n
is
domina
n
t. At this poi
nt, the
diffuse
co
mp
onent i
s
so lit
tle effective that can b
e
re
gard
ed
as
noi
se
to deal
with. Whe
n
the
sea be
cam
e
very rou
gh, the diffuse re
flection i
s
do
minant an
d the
spe
c
ul
ar refle
c
tion can be i
gnored.
4.1. Direct
Wav
e
Po
w
e
r
Con
s
id
erin
g
the pu
re
air ch
ann
el, p
o
we
r atten
u
ation of el
e
c
trom
agn
etic wave
s
corre
s
p
ond
s to the pro
pag
ation loss in f
r
ee
spa
c
e
p
L
. Free-spa
c
e lo
ss is the b
a
si
c prop
agation
loss mode,
and si
gnal p
o
we
r re
ceive
d
by antenn
a is only a small pa
rt of the transmit
t
ing
antenn
a radi
ation po
we
r
as m
o
st e
n
e
r
gy is
spread
out to the ot
her
dire
ction
s
. The farth
e
r
the
work di
stan
ce and th
e larger the
ball a
r
ea a
r
e, t
he l
e
ss po
we
r re
ceiver
will int
e
rcepte, na
m
e
ly
the larger propag
ation lo
ss will
be.
p
L
can be
re
pre
s
ente
d
by F
o
rmul
a (13).
Whe
r
e,
R
is
comm
uni
cati
on dista
n
ce.
2
4
R
L
p
(
1
3
)
Free
-spa
ce
prop
agatio
n
is the
mo
st ba
sic an
d
simpl
e
m
e
ans of radi
o wave
comm
uni
cati
on. The
ele
c
troma
gneti
c
wave propa
gat
es
in
the free
spa
c
e
after
emitting from
the
omnidi
rectional antenna whose e
nergy will spread to a sphe
re face. Assuming that the
transmitter gain is
t
G
, receiv
er gai
n is
r
G
.The relatio
n
shi
p
betwee
n
the
received po
wer
and the
transmissio
n power can be
expresse
d a
s
:
p
r
t
t
r
L
G
G
P
P
(14)
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
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ISSN:
2302-4
046
Sea Surface Refle
c
tion an
d Powe
r Attenuation
Anal
ysis of Radio
Wa
ve…
(Yua
nm
ing Ding
)
3175
4.2. Reflec
ti
on Wav
e
Po
w
e
r
The receptio
n po
wer of
reflecte
d
wa
ve can
be g
o
t acco
rding
to the sea
su
rface
reflectio
n
coe
fficient. It is a
c
kno
w
led
ged
that the o
c
cu
pied p
r
op
ortio
n
of refle
c
ted
power i
s
e
q
u
a
l
to the squa
re
of refle
c
tion
coeffici
ent. T
he rece
ived power of
refl
ected wave
f
r
om sea
surf
ace
relative to the direct
wave can be calcula
t
ed as:
2
lg
10
r
D
P
r
(dB)
(15)
Whe
r
e,
r
is the
reflection
co
efficient of se
a surfa
c
e a
n
d
r
when the
specular reflection is
domina
n
t, otherwise
r
,
r
D
is
the rel
a
tive a
n
tenna
gai
n i
n
the
dire
ctio
n of the
spe
c
ula
r
reflectio
n
poi
nt on the sea.
The relative
antenn
a gain
is app
roximat
e
ly given by [12]:
2
10
4
5
.
1
1
10
10
4
t
G
r
r
D
(16)
4.3. Simulation Analy
s
is
The simulatio
n
paramete
r
s
are set
a
s
: receiver gain
11
r
G
dB, polari
z
ati
on mod
e
is
vertical, ele
c
tromag
netic
wave fre
que
ncy
320
f
MHz. Th
e re
ceived
power of sp
ecul
ar
reflectio
n
wa
ve and diffuse refle
c
tion wave relative to the dire
ct wave in different wind
spe
e
d
s
are sho
w
n in
Figure 5.
(a) Spe
c
ul
ar reflection
wav
e
(b) Diffuse ref
l
ection wav
e
Figure 5. Power F
adin
g
of Specula
r
an
d Diffuse
Refl
ection
Wave
Relative to Di
rect
Wave in
Different Win
d
Speed
s
As
can
be
seen f
r
om
Fig
u
re
5, the
great
er the
wi
nd
spe
ed, th
e g
r
eate
r
the
po
wer
attenuation
d
enoting m
u
ltipath fadin
g
p
henom
eno
n o
f
sea
su
rface
is mo
re
severe. In the studi
ed
rang
e of
satel
lite elevation
angle, the
ma
ximum po
wer attenuation
o
f
spe
c
ula
r
reflection
wave i
s
-10dB, whil
e that of diffuse reflectio
n
can rea
c
h to -18dB, whi
c
h mean that diffuse refle
c
tio
n
attenuation i
s
more serio
u
s than spe
c
ul
a
r
refle
c
tion.
5. Conclusio
n
In
maritim
e
satellite com
m
unica
tions, sea
surface
has a strong
reflection effect
on
satellite si
gnal, resulting i
n
multipath fading, es
peci
ally in areas with
low satellite elevation
angle. In this pape
r, the UHF
ban
d m
u
ltipath e
ffect
s of se
a su
rf
ace a
r
e
studi
ed followi
ng t
h
e
gene
ral pri
n
ciples of mod
e
ling in multipath effects.
The judgme
n
t basi
s
is o
b
tained which
determi
ne
s
whether
spe
c
ul
a reflecte
d
wave o
r
diffu
se
refle
c
ted
wa
ve domi
nate
s
in th
e
refle
c
ted
wave ba
sed
on Rayleig
h
crite
r
ion. The
powe
r
atten
uation rel
a
tive to direct wave of specu
l
a
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046
TELKOM
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KA
Vol. 12, No. 4, April 2014: 3168 – 3
176
3176
reflecte
d wav
e
on sm
ooth
se
a
surfa
c
e
and diffuse
reflecte
d wav
e
on ro
ugh sea surfa
c
e
a
r
e
simulate
d an
d analy
z
ed in
base of cal
c
ulating the
re
flection
coeffi
cient. Simulat
i
on re
sult
s sh
ow
that the gre
a
t
er the wi
nd
spe
ed i
s
, the
greate
r
the
power atten
u
a
tion of refle
c
ted
wave
will
become and the
more seri
ous multipath
fading will
b
e
. In additio
n
, diffuse
refle
c
tion attenuati
o
n
is more se
rio
u
s than
spe
c
ular reflectio
n
.
So
far, there is no a
ccu
rate measure
d
data on UHF
band el
ectro
m
agneti
c
refl
ection of sea
surfa
c
e
and
t
hese co
ncl
u
si
ons
can p
r
ovi
de refe
ren
c
e
for
multipath eff
e
ct analysi
s
of se
a
surface i
n
data post-process
ing stage i
n
Maritime satellite
comm
uni
cati
ons.
Ackn
o
w
l
e
dg
ment
This
work was supp
orted
by the Scientif
ic Re
sea
r
ch Proj
ect o
f
Liaoning P
r
ovince
Educatio
nal Committee
(No.L2
012
440
).
Referen
ces
[1]
Lia
ng Q, Chen
J. Actualit
y
a
nd Future D
e
v
e
lo
pment of U
H
F Satellite C
o
mmunic
a
tio
n
.
Chin
ese N
e
w
T
e
leco
mmunic
a
tions
. 20
07; 9
(
11): 26-2
8
.
[2]
Karasa
w
a
Y, Shiok
a
w
a
T
.
Characteristics of
L-
Ban
d
Multi
p
a
t
h F
adin
g
Due
to Sea Surface
Reflectio
n
:
Antenn
as an
d Propa
gati
on.
IEEE Transacti
ons on Ant
enn
as and Pro
p
a
g
a
tion
. 19
84; 32
(6): 618-6
23.
[3]
Don
g
M, Z
hao Y,
Z
hang S. Rese
arch on
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ea Surface
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ath Mod
e
l of Meter Band.
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a
l
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09; 36(6): 13
73-
13
77.
[4]
Meng Y,
Le
e Y
.
Multipath
Ch
a
r
acteri
z
a
ti
on
a
nd F
a
d
e
Miti
ga
tion of A
i
r-to-Groun
d Pro
pag
a
t
ion C
h
a
nne
l
Over T
r
opica
l
Sea S
u
rface
at C B
a
n
d
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y
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l
S
y
mp
osi
u
m (APSURSI).
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o
ronto. 201
0: 1-4.
[5]
Liu Y, D
a
n
g
Y,
Z
hang S. Pr
eli
m
inar
y M
u
ltip
ath Mod
e
li
ng B
a
sed o
n
Se
a Su
rface Envir
onm
ent.
Scienc
e
of Surveyin
g a
nd Map
p
in
g
. 2
013; 38(
1): 122
-124.
[6]
Stotts LB. Closed Form Expre
ssion for Optic
a
l Puls
e Broa
d
eni
ng i
n
Multi
p
l
e
-Scatterin
g
Medi
a.
Ap
p
lied
Optics
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7
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50
5.
[7]
Yang
XK, Ya
n
g
XL. Ne
w
E
l
e
v
ation
Calc
ulat
ion Formu
la
of Satellit
e Rec
e
iving A
n
ten
na.
Cabl
e T
V
T
e
chno
logy
. 2
010; 1: 38-
41.
[8]
Bucco D, C
h
is
holm JD. C
o
m
paris
on of Scat
tering M
ode
ls for Pred
icatin
g
Rad
a
r Multi
pat
h Effects over
the Sea.
Ameri
c
an Institute of Ae
ron
autics a
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