ANTARES Project: Visibility Analysis

Transcription

1 Template reference : S-EN ANTARES Project: Visibility Analysis Paolo Conforto Iris Information Event Prague, May, 2010

2 Contents Page 2 Visibility analysis objectives Analysis model description Visibility analyses results Inputs from aviation Conclusions and way forward

3 Visibility Analysis Objectives Page 3 The visibility analysis aims at Evaluating the geometrical availability of the link between aircraft and satellite Contribution to the overall system availability which may be offered to the aviation end-users Identifying solutions to increase satellite link geometrical availability System dimensioning to cope with real flight conditions Number of antennas on the aircraft Number of satellites simultaneously operating NorthAmerica 3 Brazil Azerbaijan7 Egypt: India 49 China 29 Australia 92

4 Simulation Model Page 4 Main elements of the simulation model Geostationary satellite Its position on the orbital arc can be varied for analysis purpose More than one satellite can be considered for diversity purposes Aircrafts Suitable typologies may be selected from a list of possible models Position of the satellite terminal antenna can be selected Flight trajectories Instrument flight rules (IFR)-based trajectories imported Special trajectories generated Satellite link between aircraft and satellite

5 Aircraft Models Page 5 Two aircraft models considered in the analysis (many others can be considered) Airliner - Boeing B Civil (small) aircraft - Cessna 172 One antenna for each aircraft Sensor modelling the real antenna field of view (FOV) Several antenna locations investigated 5 candidate locations for Airliner - Boeing B 2 candidate locations for Civil aircraft - Cessna o 120 o 90 o

6 Visibility Analysis Outputs Page 6 Several types of geometrical parameters investigated Visibility and outage events on the satellite link Aircraft antenna field of view obstruction caused by the aircraft body (tail, wing and nose) Link visibility time duration and percentage Link outage time duration and percentage Maximum link outage time duration Aircraft antenna-to-satellite elevation angles occurrences statistics Aircrafts flight trajectories bank and pitch angles occurrences statistics The above results may be provided in two major scenarios based on One geostationary satellite Two geostationary satellites operating in spatial diversity

7 Flight Trajectories Page flight trajectories over the ECAC are simulated Flight Trajectories [1-500] Flight Trajectories [ ]

8 Airliner Link Outage Statistics Page 8 Geometrical visibility analyses for five different antenna locations on the airliner Total flights durations (for 1000 trajectories) Link visibility time duration and percentage Link outage time duration and percentage Maximum link outage occurrence duration Max link outage duration (sec) 3.0 s 5.0 s 13.2 s 42.4 s 0 s Link availability (%) % % % % 100% Link outage percentage (%) Antenna positions % % % 0.049% 0% N1 N2 C1 T2 T1

9 Small Aircraft Link Outage Statistics Page 9 Two antenna positions considered for the small aircraft Geometrical visibility analyses The same types of parameters analysed Slightly different results Max link outage duration (sec) 66.4 s 4.2 s Link availability (%) % % Link outage percentage (%) 0.157% % Antenna positions C1 T1

10 Satellite Orbital Position Diversity Page 10 Two geostationary satellites active with 2 degrees orbital separation Airliner antenna position N1 N2 C1 T1 T2 Link outage reduction with satellite diversity 92 % 81% 41% 0% (no link outage) 82%

11 Aircraft-to-Satellite Elevation Angles Page 11 Elevation angle Depends on Aircraft position (latitude and longitude) Aircraft manoeuvring Impacts on Aircraft antenna gain 90 o Elevation Angle θ2=20 Elevation angles 0 % -30 o o 5 θ Max antenna gain 90 o 90 o o -30 o o o Elevation Angle θ1=40 θ3 0 θ<5-10 θ<0-30 θ< Min antenna gain Stockholm Rome

12 Flight Trajectories Bank Angles Statistics (1/2) Page 12 Flight trajectories bank angle occurrences percentage The maximum aircrafts bank angle observed is 27 degrees

13 Flight Trajectories Bank Angles Statistics (2/2) Page 13 Maximum duration of flight trajectories bank angle occurrences

14 Flight Trajectories Pitch Angles Statistics Page 14 Flight trajectories pitch angle occurrences percentage The maximum aircraft pitch angle observed is 17 degrees

15 Conclusions and Way Forward Page 15 The visibility analysis results have shown that A high level of geometrical link availability can be achieved by suitably installing the aircraft antenna The geometrical link availability can be further increased with satellite diversity Elevation angles statistics can allow to infer good performance for the aircraft antenna Inputs from aviation may Allow a refinement of the visibility analysis model Concern possible constraints or preferences on antenna installation on the aircrafts, e.g. Recommended positions Allowed and not allowed positions Maximum number of antennas Model extension to consider Focused study cases for statistical analysis of special flight trajectories Different aircraft models