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http://marsrover.nasa.gov/classroom/Communication via the Mars Orbiter
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0452-01
FIGURE 1
Long-term interference propagation mechanisms
Tropospheric scatter
Diffraction
Line-of-sight
90?&
Reflection
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0452-02
FIGURE 2
Anomalous (short-term) interference propagation mechanisms
Hydrometeor scatter
Elevated layerreflection/refraction
Ducting
Line-of-sight withmultipath enhancements
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!M&6:(5N"O& 34
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!M&6:(5N"O& 35
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!M&6:(5N"O& 36
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!M&6:(5N"O& 37
2.00
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2.40
2.50
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!M&6:(5N"O& 38
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!M&6:(5N"O& 39
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!M&6:(5N"O& 40
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– `,2&/"5.2&%<&.$*,"7&"Y2,5"+%,4&:%&V"77.L&)(2/$)$:"+%,.&Q("$,L&.,%VL&.",#R&",#&":8%.)12($/&*".2.&
!M&6:(5N"O& 41
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!M&6:(5N"O& 42
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!M&6:(5N"O& 45
65)2(>(2<("/+%,&",#/+,*&
Actual Earth with radius 6 370 km
Standard atmosphere(– 40 N units/km)
(– 157 N units/km)
Ducting(– 157 N units/km)
More negative
Less negative
Atmospheric refraction effects on radio signal propagation
!M&6:(5N"O& 46
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!M&6:(5N"O& 47
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!M&6:(5N"O& 50
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!M&6:(5N"O& 51
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– Z"(*2&#":"4".2.&• 6":277$:2@&"2($"7&)1%:%*(")1.&%(&("#"(&$8"*2.L&&&&
!M&6:(5N"O& 52
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!M&6:(5N"O& 53
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!M&6:(5N"O& 54
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!M&6:(5N"O& 55
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Source: NASA (http://www2.jpl.nasa.gov/srtm/)
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!M&6:(5N"O& 60
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!M&6:(5N"O& 62
