JED - July 2015 - 44

E W101

Attenuation in dB per km

added empirical data which makes it more useful.
Hata gives some closed-form equations for median
path loss in urban areas. (See page 364 of the
0.4
referenced handbook.) Plugging in some numbers,
the median path loss for a 10-km path through
a city at 1 GHz with a 33-meter-high transmit
Somewhat
antenna and a 3-meter-high receiving antenna
Less for
0.3
predicts approximately 161 dB path loss. Hata
Horizontal
gives correction factors for large cities and subPolarization
urban areas which make relatively small changes
to this value.
0.2
The Okumura and Hata models give approxiIndependent
mations,
but accurate predictions must be made
of
from computer programs that use environment
Polarization
0.1
models. Mr. McLarnon gives one suggestion for a
starting point (described as "crude but useful." The
suggestion is taken from J.D. Parsons' book, The
Mobile Radio Propagation Channel (Wiley, 1992).)
1
0.2 0.5
2
This approach is to approximate loss in an urban
3
Frequency in GHz
environment by assuming line-of-sight loss out
to 1 km and two-ray propagation beyond 1 km.
Figure 2: Attenuation through a dense forest depends on the distance through
One comment in literature is that antennas
Figure 2: Attenuation through a dense forest depends on the distance through the
the forest and the frequency.
forest and the frequency.
above the roof top heights will provide signifinet received-signal strength will be the vector sum of all
cantly lower loss paths.
of these signals.
My personal field experience supports the assertion that
In the IEEE Mobile Communications Handbook, the Okumura
when your receiver is within line of sight of a transmitter in
an urban or suburban environment, propagation is reasonably
Model for urban area radio propagation is described as the most
close to the line of sight propagation model. I suspect this is
widely used propagation model. However, the Hata Model has

The Journal of Electronic Defense | July 2015

44

XMTR

BUILDING

BUILDING

BUILDING

BUILDING

BUILDING

BUILDING

RCVR

Figure 3: An urban or suburban environment has significant numbers of multi-path components to received signals.



JED - July 2015

Table of Contents for the Digital Edition of JED - July 2015

The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
World Report
The Modern MANPADS – an Evolving Threat
Technology Survey: RF Tuners and Tuner Modules for SIGINT Applications
EW 101
AOC News
Index of Advertisers
JED Quick Look
JED - July 2015 - cover1
JED - July 2015 - cover2
JED - July 2015 - 3
JED - July 2015 - 4
JED - July 2015 - 5
JED - July 2015 - The View From Here
JED - July 2015 - 7
JED - July 2015 - Conferences Calendar
JED - July 2015 - 9
JED - July 2015 - Courses Calendar
JED - July 2015 - 11
JED - July 2015 - From the President
JED - July 2015 - 13
JED - July 2015 - 14
JED - July 2015 - The Monitor
JED - July 2015 - 16
JED - July 2015 - 17
JED - July 2015 - 18
JED - July 2015 - 19
JED - July 2015 - 20
JED - July 2015 - 21
JED - July 2015 - World Report
JED - July 2015 - 23
JED - July 2015 - 24
JED - July 2015 - 25
JED - July 2015 - The Modern MANPADS – an Evolving Threat
JED - July 2015 - 27
JED - July 2015 - 28
JED - July 2015 - 29
JED - July 2015 - 30
JED - July 2015 - 31
JED - July 2015 - 32
JED - July 2015 - Technology Survey: RF Tuners and Tuner Modules for SIGINT Applications
JED - July 2015 - 34
JED - July 2015 - 35
JED - July 2015 - 36
JED - July 2015 - 37
JED - July 2015 - 38
JED - July 2015 - 39
JED - July 2015 - 40
JED - July 2015 - 41
JED - July 2015 - 42
JED - July 2015 - EW 101
JED - July 2015 - 44
JED - July 2015 - 45
JED - July 2015 - AOC News
JED - July 2015 - 47
JED - July 2015 - 48
JED - July 2015 - Index of Advertisers
JED - July 2015 - JED Quick Look
JED - July 2015 - cover3
JED - July 2015 - cover4
https://www.nxtbook.com/naylor/JEDM/JEDM0318
https://www.nxtbook.com/naylor/JEDM/JEDM0218
https://www.nxtbook.com/naylor/JEDM/JEDM0118
https://www.nxtbook.com/naylor/JEDM/JEDM1217
https://www.nxtbook.com/naylor/JEDM/JEDM1117
https://www.nxtbook.com/naylor/JEDM/JEDM1017
https://www.nxtbook.com/naylor/JEDM/JEDM0917
https://www.nxtbook.com/naylor/JEDM/JEDM0817
https://www.nxtbook.com/naylor/JEDM/JEDM0717
https://www.nxtbook.com/naylor/JEDM/JEDM0617
https://www.nxtbook.com/naylor/JEDM/JEDM0517
https://www.nxtbook.com/naylor/JEDM/JEDM0417
https://www.nxtbook.com/naylor/JEDM/JEDM0317
https://www.nxtbook.com/naylor/JEDM/JEDM0217
https://www.nxtbook.com/naylor/JEDM/JEDM0117
https://www.nxtbook.com/naylor/JEDM/JEDM1216
https://www.nxtbook.com/naylor/JEDM/JEDM1116
https://www.nxtbook.com/naylor/JEDM/JEDM1016
https://www.nxtbook.com/naylor/JEDM/JEDM0916
https://www.nxtbook.com/naylor/JEDM/JEDM0816
https://www.nxtbook.com/naylor/JEDM/JEDM0716
https://www.nxtbook.com/naylor/JEDM/JEDM0616
https://www.nxtbook.com/naylor/JEDM/JEDM0516
https://www.nxtbook.com/naylor/JEDM/JEDM0416
https://www.nxtbook.com/naylor/JEDM/JEDM0316
https://www.nxtbook.com/naylor/JEDM/JEDM0216
https://www.nxtbook.com/naylor/JEDM/JEDM0116
https://www.nxtbook.com/naylor/JEDM/JEDM1215
https://www.nxtbook.com/naylor/JEDM/JEDM1115
https://www.nxtbook.com/naylor/JEDM/JEDM1015
https://www.nxtbook.com/naylor/JEDM/JEDM0915
https://www.nxtbook.com/naylor/JEDM/JEDM0815
https://www.nxtbook.com/naylor/JEDM/JEDM0715
https://www.nxtbook.com/naylor/JEDM/JEDM0615
https://www.nxtbook.com/naylor/JEDM/JEDM0515
https://www.nxtbook.com/naylor/JEDM/JEDM0415
https://www.nxtbook.com/naylor/JEDM/JEDM0315
https://www.nxtbook.com/naylor/JEDM/JEDM0215
https://www.nxtbook.com/naylor/JEDM/JEDM0115
https://www.nxtbookmedia.com