1. 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 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) 4152030 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)41.88 37.95 Longitude (° E)12.48 23.63 Ionospheric Condition SSNmonthtimeMagnetic field 150418No azimuth (°)111 Distance(R gr )[km]1059 InputParameters Simulation Steps: Carrier frequency (MHz) HPBW (°) 5101 679 775 860 953 1051 1151 1438 1542 1643 1739 1839 1936 2034 2134 2226 2324 2519 SIRM simulation MUF 90%=13MHzβ 0 =34°

6. Results 2.Computation of the minimum (β min ) and the maximum (β max ) elevation angle @MUF90% 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 0.0001° 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 290.38 ms|0.26| Hz0.05 Hz

8. 2° Scenario: Rome-Barcelona Link Tx location (CGA-Rome) Rx location (ECI-Barcelona) Latitude(° N)41.88 41.38 Longitude(° E)12.48 2.17 Ionospheric Condition SSNmonthtimeMagnetic field 150418No 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 480.28 ms|0.25| Hz0.05 Hz

9. Tx location (CGA-Rome) Rx location (ECI-Cefalù) Latitude (° N)41.88 38.03 Longitude (° E)12.48 14.05 Ionospheric Condition SSNmonthtimeMagnetic field 150418No 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 720.21 ms|0.2| Hz0.05 Hz