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09-11-2012 Rome, February 14, 2013 Status of the Project Report on the first year activities With the support of the Prevention, Preparedness and Consequence.

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Presentation on theme: "09-11-2012 Rome, February 14, 2013 Status of the Project Report on the first year activities With the support of the Prevention, Preparedness and Consequence."— Presentation transcript:

1 Rome, February 14, 2013 Status of the Project Report on the first year activities With the support of the Prevention, Preparedness and Consequence Management of Terrorism and other Security-related Risks Programme European Commission - Directorate-General Home Affairs

2 Characterization of the HF channel Ionospheric Channel Properties Ionospheric Channel Properties Long-haul communications in HF band Main critical aspect Main critical aspect Ionospheric channel behaviour is spatial-time dependent Effects Doppler Shift Delay Spread Doppler Spread Ionospheric Channel estimation is needed

3 Ionospheric Channel Model Ionospheric Channel Model Ray-tracing algorithm with Watterson’s model Received Signal  Weighted (g iT (t)) sum of copies of the transmitted signal.  Each copy is characterized with a different delay ( Ƭ i ). The tap gain function is modeled as a Gaussian process accoridng to the ITU–R F.1487 Doppler Spread Is provided by the σ of tap gain spectrum Carrier Frequency (MHz) V r =3 m/s0.08 Hz0.3 Hz0.4 Hz0.6 Hz V r =12 m/s0.32 Hz1.2 Hz1.6 Hz2.4 Hz Doppler Spread and Doppler Shift Evaluation Doppler Spread and Doppler Shift Evaluation

4 Delay Spread Evaluation Delay Spread Evaluation The presence of multipath produces a signal dispersion in the time domain Time Dispersion or Delay Spread Difference between the maximum and minimum propagation delay associated to the multipath components. Ray Tracing Algorithm Assumptions Group path is a indipendent variable. Group path is a indipendent variable. 3D stratified ionosphere. 3D stratified ionosphere.

5 Results 1.Evaluation of the Frequency and elevation angle pair refers to the MUF90% (the SIRM model has been used). 1° Scenario: Rome-Pireo Link Tx location (CGA-Rome)Rx location (ECI-Pireo) Latitude (° N) Longitude (° E) Ionospheric Condition SSNmonthtimeMagnetic field No azimuth (°)111 Distance(R gr )[km]1059 InputParameters Simulation Steps: Carrier frequency (MHz) HPBW (°) SIRM simulation MUF 90%=13MHzβ 0 =34°

6 Results 2.Computation of the minimum (β min ) and the maximum (β max ) elevation 1° Scenario: Rome-Pireo Link 3.Application of the ray-tracing algorithm to elevation values obtained by the sampling of the antenna aperture (sampling step size is 0.05°). 4.Extraction of the elevation angles (Δβ) related to the all paths that fall into 100m around the receiver. 5.Application of the ray-tracing algorithm to elevation interval Δβ. A sampling step size of ° has been assumed.

7 Results 1° Scenario: Rome-Pireo Link Electron density profile and ray- paths (Pireo site) Electron density profile and ray-paths (Pireo site) Zoom of the figure NRNR time delayDoppler-shift Doppler-spread ms|0.26| Hz0.05 Hz

8 2° Scenario: Rome-Barcelona Link Tx location (CGA-Rome) Rx location (ECI-Barcelona) Latitude(° N) Longitude(° E) Ionospheric Condition SSNmonthtimeMagnetic field No azimuth (°)270 Distance(R gr )[km]867 InputParameters Carrier frequency (MHz)12 Elevation angle (deg)42 β min β min (deg) 17 β max β max (deg)67 Transmitted Signal Parameters Electron density profile and ray- paths Zoom of the figure NRNR time delay Doppler-shiftDoppler-spread ms|0.25| Hz0.05 Hz

9 Tx location (CGA-Rome) Rx location (ECI-Cefalù) Latitude (° N) Longitude (° E) Ionospheric Condition SSNmonthtimeMagnetic field No azimuth (°)163 Distance(R gr )[km]452 3° Scenario: Rome-Cefalù Link InputParameters Carrier frequency (MHz)13 Elevation angle (deg)34 β min β min (deg) 15 β max β max (deg)53 Transmitted Signal Parameters Electron density profile and ray-paths (Pireo site) Electron density profile and ray-paths Zoom of the figure NRNR time delay Doppler-shiftDoppler-spread ms|0.2| Hz0.05 Hz


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