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Wave probigation

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For a course for an amateur radio license.

For a course for an amateur radio license.

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Wave probigation Wave probigation Presentation Transcript

  • Wave Probigation
  • Overview
    Waves and ionisation
    Atmosphere
    Ionosphere
    Troposphere
    Other methods
  • Radio Waves
    Electromagnetic energy
    Models
    Waves
    Particles
    Electrical part
    Magnetic part
    Polarisation
    Vertical
    Horizontal
  • Ionisation
    Ion
    Protons != electrons
    Ionisation
    Removal or addition of an electron
    Energy
  • Atmosphere
  • Atmosphere
    Troposphere
    Ground to 7-17 km out - Temp dec. with height
    80% of the mass
    Stratosphere
    About 51 km out – Temp inc. with height
    Mesosphere
    80-85 km out – temp at – 85 deg C
    Thermo sphere
    350 – 800 km out – temp +1 500 Deg C
    Exosphere
  • Atmosphere
    Troposphere
    Thermo sphere
    Exosphere
    ionosphere
  • Ionosphere
  • Ionosphere
    100 – 300 km
    Ionisation of particles
    Sun
    Thin atmosphere
    Shell of electrons
    Layers
    Radio propagation
    “acts like a mirror”
    At certain frequencies
  • Ionosphere
  • Ionosphere
    D layer
    Ionising NO (some N2 and O2)
    Electron collision high
    Results in blocking of HF radio waves
    < 10 MHz
    Almost disappears after sunset
    HF can pass through if broadcasted directly up
  • Ionosphere
    E (Heavyside) layer
    Ionisation of O2
    Refracts radio waves < 10 MHz
    Nordic area
    At night, increasing height inc. range
    Es layer
    Sporadic – best during the summer
    Refracts up to 50 Mhz
    Distance of 1000 km
  • Ionosphere
    F (Appleton) layer
    Ionising of O – dense
    Refracts most HF radio waves (3-30 MHz)
    Skywaves
    F1 and F2 layers
    Exist during the day
  • Ionosphere
    Fading
    Changes in the ionosphere
    Changes the polarisation
    Angle
    Critical angle
    Depends on ionosphere and frequency used
    Hi angle and Hi F pass through.
  • Using the Ionosphere
  • Using the Ionosphere
    Nordic region
    3.5 – 7 MHz
    Dipole
    Straight out
    Using D layer
    14 – 30 MHz
    Uses E and F layers (low elevation angle)
    2 000 – 4 000 Km
  • Using the Ionosphere
    DX traffic
    DX – distance
    Dipole or yagi array
    For Europe
    30 Deg
    0.5 Wave length
    Out side Europe
    1 -2 X wave length
    10 Deg 1.5 X wave length
  • Troposphere
    Its damp!
    99% of the water vapour!
    Effects radio transmissions
    Hi F = more absorption
    Used for VHF, UHF and SHF transmissions
    Line of sight
    20- 30 km (depends on power)
    Can scatter (refraction)
    Up to 2 000 km
  • Other Methods
    Earth-Moon-Earth (EME)
    144 MHz, 434 MHz and 1 296 MHz
    As far away as Australia!
    Meteors
    Same as EME
    Short burst
    Auroras
    > 25 MHz
    NW -> NE aerial
  • Questions?