Download - Losangle Lakers
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Review Path Profling
Site Selection
Antenna Heights
Reection Points
Transmission Calculations
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Path Profling Topographic Maps Longitude, Lattitude
TM
Map Scaling
Contour Lines
Magnetic !eclination
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Site Selection Considerations in selecting site
•Site Selection
• Tower Selection
• Power "#uipment
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Reection Points Reection Points should &e avoided
The' cause inter(erence, whether the'&e constructive or destructive
Moving Reection Point
Shielding Reection Point
)inds o( Reection
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Line o( Sight The line of sight is a straight line along which an
o&server o&serves an o&+ect
-t is an imaginar' line that stretches &etweeno&server.s e'e and the o&+ect that he is loo/ing at
The simplest mode o( propagation o( radio waves isthe propagation along line o( sight paths
Propagation will generall' &e said to &e in line o(sight when di0raction phenomena are negligi&le
-n contrast with scattering pro&lems, the o&servedwave in light o( sight propagation is alwa's ami1ture o( the incident and scattered wave
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2ave Propagation An electromagnetic wave is created &' a
local distur&ance in the electric and
magnetic felds $rom its origin, the wave will propagate
outwards in all direction
-( the medium in which it is propagating
3air (or e1ample4 is the sameever'where, the wave will spread outuni(orml' in all directions
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Suppose that we were given a tas/ o(per(orming radio planning (or a new networ/
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-denti(' customer end sitelocations
This is ver' important
Microwave radio lin/s allow ver' littleinaccurac' o( the site coordinates&ecause the clearance o( the &eam iscritical
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Plot the 5etwor/ !iagram and-nitial Mapwor/
Microwave radio lin/s rel' on there&eing L6S &etween the two ends
-( there is no L6S, the path will not wor/7 The path is &loc/ed etc
$or long L6S path, repeaters should &eused
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Path Profling Repeaters are ver' e1pensive
Radio repeaters are o(ten &uilt &ased onthe anal'sis o( the path profle
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Radio Repeaters
Passive and Active
Passive 7 5o power is re#uired, noregular road access, no e#uipmenthousing, environmental (riendl' and nomaintenance
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-ncluded Angle2hen two lines meet at a common point
the angle &etween them is called the
included angle The two lines defne theangle So (or e1ample in the fgurea&ove we could re(er to the angle 8A9Cas the :included angle o( 9A and 9C:
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2here;• ro< true earth radius3=>?@
miles
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2here is thelongitude, is thelatitude and site @is lower than site
D
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What’s the azimuth?
the angle &etween the pro+ected vector and are(erence vector on the re(erence plane is calledthe aEimuth
• AEimuth is usuall' measuredin degrees 3F4The concept isused in navigation,
astronom', engineering,mapping, mining and artiller'
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-n land navigation, aEimuth is usuall'denoted alpha, and defned as a
horiEontal angle measured cloc/wise(rom a north &ase line or meridianAEimuth has also &een more generall'defned as a horiEontal angle measured
cloc/wise (rom an' f1ed re(erenceplane or easil' esta&lished &asedirection line
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True north-based azimuths
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Computing (or aEimuth2e are standing at latitude , longitude
EeroG we want to fnd the aEimuth (rom
our viewpoint to Point D at latitude ,longitude L 3positive eastward4 2e canget a (air appro1imation &' assumingthe "arth is a sphere, in which case the
aEimuth is given &'
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2hat is "levation The elevation is
the vertical
angular distance&etween a &od'and theo&server.s local
horiEon or, alsocalled, theo&serverIs localplane
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