Radar Cross Section Analysis of Aircraft using CONCEPT-II

Transcription

1 Radar Cross Section Analysis of Aircraft using CONCEPT-II Arne Schröder University of Bern - Institute of Applied Physics Microwave Physics WS2, Modeling of EMC Problems Using CONCEPT-II

2 Radar - Radio Detection and Ranging

3 Radar - Radio Detection and Ranging, Conventional Radar

4 Radar - Radio Detection and Ranging, Passive Radar

5 Key Quantity: Radar Cross Section (RCS) RCS = lim r 4πr 2 E sca 2 E inc 2

6 Key Quantity: Radar Cross Section (RCS) RCS = lim r 4πr 2 E sca 2 E inc 2 Bistatic RCS Monostatic RCS Multistatic RCS - transmitter and receiver at diff. positions - transmitter and receiver at same position - multiple excitations - time consuming computation - multiple transmitters/receivers - arbritrary angles of incidence

7 1 A Typical CONCEPT-II Simulation Procedure 2 Bi- and Monostatic RCS Computations 3 Multistatic RCS Computations 4 Conclusion

8 1 A Typical CONCEPT-II Simulation Procedure 2 Bi- and Monostatic RCS Computations 3 Multistatic RCS Computations 4 Conclusion

9 Typical CONCEPT-II Simulation Procedure Starting point: CAD model, often mechanical model

10 Typical CONCEPT-II Simulation Procedure Starting point: CAD model, often mechanical model CAD cleaning, creating a surface model with CAD tools Closing gaps and overlaps between surfaces Removing detailed geometries like screws, springs etc. Simplification of internal structure

11 Typical CONCEPT-II Simulation Procedure

12 Typical CONCEPT-II Simulation Procedure Starting point: CAD model, often mechanical model CAD cleaning, creating a surface model with CAD tools Closing gaps and overlaps between surfaces Removing detailed geometries like screws, springs etc. Simplification of internal structure Surface mesh generation, i.e. using gmsh

13 Typical CONCEPT-II Simulation Procedure

14 Typical CONCEPT-II Simulation Procedure Starting point: CAD model, often mechanical model CAD cleaning, creating a surface model with CAD tools Closing gaps and overlaps between surfaces Removing detailed geometries like screws, springs etc. Simplification of internal structure Surface mesh generation, i.e. using gmsh CONCEPT-II simulation

15 Typical CONCEPT-II Simulation Procedure

16 Typical CONCEPT-II Simulation Procedure

17 Typical CONCEPT-II Simulation Procedure Starting point: CAD model, often mechanical model CAD cleaning, creating a surface model with CAD tools Closing gaps and overlaps between surfaces Removing detailed geometries like screws, springs etc. Simplification of internal structure Surface mesh generation, i.e. using gmsh CONCEPT-II simulation CONCEPT-II post-processing, external post-processing, i.e. in MATLAB

18 1 A Typical CONCEPT-II Simulation Procedure 2 Bi- and Monostatic RCS Computations 3 Multistatic RCS Computations 4 Conclusion

19 Bistatic Example Airbus A320 Incidence: θ = 90, φ = 0, vertical polarization RCS for: φ = , φ = 0.5 Frequency: 120 MHz

20 Airbus A320 Simulation Setup

21 Airbus A320 Post-Processing

22 Airbus A320 Results CONCEPT HFSS RCS [db(m 2 )] Angle [ ]

23 Monostatic Example NASA Almond Monostatic RCS for: φ = , θ = excitation vectors θ-polarization

24 NASA-Almond Monostatic Setup MLFMA solver RHS compression using ACA, accuracy: 10 5

25 NASA Almond Results θ [ ] φ [ ] RCS [db λ 2 ] 0.9 h and 0.7 GB with CONCEPT-II Not possible in HFSS, memory >120 GB

26 NASA Almond Results RCS [db(m 2 )] CONCEPT HFSS Angle [ ] 0.9 h and 0.7 GB with CONCEPT-II Not possible in HFSS, memory >120 GB

27 1 A Typical CONCEPT-II Simulation Procedure 2 Bi- and Monostatic RCS Computations 3 Multistatic RCS Computations 4 Conclusion

28 Multistatic Example Trajectory Observer Transmitter 1 Airport Bern-Belp Transmitter 2 Aim: Computation of RCS depending on position on trajectory

29 Transmitter 1 Trajectory Transmitter 2 Airport Observer Setup 200 MHz, typical T-DAB frequency Evektor EV-55 aircraft Pre-processing in MATLAB Coordinates of observer, transmitter, trajectory in WGS 84 Computation of incident angles, observation angles

30 CONCEPT-II setup Excitation: Bistatic RCS, angles from file RHS compression: ACA, accuracy: RHSs 31 RHSs

31 Multistatic Example Results Radar Cross Section [db(m 2 )] Transmitter 1 Transmitter Relative Position CONCEPT-II: 12 h, 7 GB - MLFMA 3.3 h, 5 GB - Fast Direct Solver HFSS: computation time h = 41 d

32 1 A Typical CONCEPT-II Simulation Procedure 2 Bi- and Monostatic RCS Computations 3 Multistatic RCS Computations 4 Conclusion

33 Conclusion CONCEPT-II... provides import option for real aircraft models solves large RCS problems efficiently due to ACA-compression of excitation matrix provides fast direct solver, perfectly suited for monostatic RCS problems can treat arbritray angles of incidence and observation angles is well-suited for RCS computation of aircraft

34 Thank you for your attention!

35 P r = P tg t A r σf 4 (4π) 2 R 2 t R2 r