A Preliminary Assessment of Specular Radar Cross Section Performance in the Sukhoi T-50 Prototype

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Abstract

This study has explored the specular Radar Cross Section of the Sukhoi T-50 prototype aircraft shaping design. Simulations using a Physical Optics simulation algorithm were performed for frequencies of 150 MHz, 600 MHz, 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz and 28 GHz without an absorbent coating, and for frequencies of 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz with an absorbent coating, covering all angular aspects of the airframe. Modelling has determined, that if the production T-50 retains the axisymmetric nozzles and smoothly area ruled sides, the aircraft would still deliver robust Very Low Observable performance in the nose aspect angular sector. Conversely, if the production T-50 introduces a rectangular faceted nozzle design, and refinements to fuselage side shaping, the design would present very good potential for robust Very Low Observable performance in the S-band and above for the nose and tail aspect angular sectors, with marginal performance in the beam aspect angular sector. This study has therefore established through Physical Optics simulation across nine radio-frequency bands, that no fundamental obstacles exist in the shaping design of the T-50 prototype, which might preclude its development into a genuine Very Low Observable design with constrained angular coverage.

Index

1. Index
2. Introduction
3. T-50 Prototype Very Low Observable Airframe Shaping Design Features
4. Radar Cross Section Simulation Method / Simulator Design and Capabilities
1. Aircraft Model Features and Limitations
2. What the Simulation Does and Does Not Demonstrate
5. Specular Radar Cross Section Simulation Results
1. Analysis of Shape Related Specular Radar Cross Section
2. Analysis of Specular RCS with a RAM Coating
6. Conclusions
7. Endnotes, References and Bibliography
8. Annex A Scales, Bands, Geometries
9. Annex B Viewing RCS Plots
10. Annex C Glossary of Terms
11. Annex D What the Simulation Does Not Demonstrate
12. Annex E Comparative Analysis of Specular RCS - T-50 Versus J-20
13. Annex F Additional Notes on Physical Optics RCS Modelling