Abstract TOC Chapter 1To5 Jul
Total Page：16
File Type：pdf, Size：1020Kb
i ABSTRACT In the light of the increasing terrorist SAMs threat to civil and military aircraft, the need of a high-fidelity, low-cost, IR signature scene modelling and simulation capability that could be used for development, testing and evaluation of IRCM systems cannot be overlooked. The performance evaluation, training and testing of IR missiles or other IR based weapon systems, is very expensive and is also dependent upon atmospheric factors. Whereas, the computer based non-destructive simulation can provide a cost-effective alternative to field trials. An effort has been made to model the IR scene signature using virtual reality modelling tools and integrating this model into the missile-target engagement and countermeasure simulator. The developed algorithm can simulate passive IR imaging seeker engagements with aerial targets. The presented algorithm uses the developed models for IR signature of the target, the background, the flare spectral and temporal responses and the flare ballistic trajectory. The missile guidance, auto-pilot and tracker algorithms have also been developed. The atmospheric conditions have been modelled, using LOWTRAN, as “good”, “typical” or “bad” to account for atmospheric transmittance and the sky-radiance. The results were analysed and validated through four test scenarios. The code is written in MATLAB which gives it openness for user verification/validation and also flexibility for any future modifications. The work presented may help the IRCM designer and pilots to evaluate potential strategies to defeat the imaging seeker threat. ii DEDICATION Specially dedicated with love and prayers to my mother who is suffering from “Pulmonary Fibrosis” disease. Secondly, dedicated to my father, sisters and brother who have always prayed and guided me throughout my life. Finally, dedicated to my gorgeous wife and lovely children for their patience and support during my PhD. iii ACKNOWLEDGEMENTS I was able to accomplish this immense task mainly because of the whole hearted support, valuable guidance, professional critic and moral support extended to me by Dr. Mark A. Richardson, who has supervised this research, leading to PhD thesis, in a very friendly and encouraging atmosphere. I am extremely thankful to Dr Mark for all his support and the time he devoted for in depth review of my thesis. Many of the ideas explored in this research were contributed by individuals who gave their time and supported me at different stages of this work. In particular, I would like to thank Professor Richard Ormondroyd, Dr. Martin L. Fair of DSTL (UK), Dr Evan Hughes, Dr. Robin Jenkin, Dr. John Coath, Mr. Roy Walmsley of Chemring Countermeasures, High Post, UK and Dr. Peter Silson. I would like to thank my departmental staff for their support. Also, I would like to thank fellow research students at Post Graduated Centre for staying long hours together and sharing ideas. Finally, I would like to thank the NUST, Pakistan for sponsoring me and Pakistan Air Force for sparing me for this research work. iv TABLE OF CONTENTS ABSTRACT .................................................................................................................. ii DEDICATION ............................................................................................................ iii ACKNOWLEDGEMENTS ....................................................................................... iv TABLE OF CONTENTS ............................................................................................ v LIST OF TABLES ..................................................................................................... xv LIST OF FIGURES .................................................................................................xvii ACRONYMS .......................................................................................................... xxiii 1 INTRODUCTION ................................................................................................ 1 1.1 Background....................................................................................................1 1.2 Aim ................................................................................................................1 1.3 Objectives ......................................................................................................1 1.4 Need of IR Signature Modelling and Simulation ..........................................2 1.5 Why Commercial Off-the-Shelf?...................................................................2 1.6 Future Utility..................................................................................................3 1.7 Summary........................................................................................................3 2 IR Radiations and Signature .............................................................................. 5 2.1 Introduction....................................................................................................5 2.2 Infrared Radiations.........................................................................................6 2.2.1 Plank’s Law for Blackbody Radiations .................................................6 2.2.2 Radiant Properties of Materials .............................................................7 2.2.3 Emissivity ..............................................................................................8 2.2.4 Spectral Radiance...................................................................................8 2.2.5 Power .....................................................................................................9 2.2.6 Solid Angle ..........................................................................................10 2.2.7 Projected Area......................................................................................11 2.3 Sources of Radiation....................................................................................11 2.3.1 Sources of Radiation on Jet Aircraft....................................................12 2.3.2 Sources of Radiation on Ground Vehicles...........................................14 2.4 Transmission of Infrared Radiation through Earth’s Atmosphere...............15 2.4.1 Atmospheric Transmittance Calculation Software ..............................15 2.4.2 Atmospheric Transmittance.................................................................17 v 2.4.3 Atmospheric Path-radiance..................................................................18 2.5 IR Signature Scene Model Ingredients ........................................................19 2.5.1 Targets..................................................................................................19 2.5.2 Background as Clutter or Source.........................................................20 2.5.3 Thermally Static IR Background .........................................................20 2.6 Low and High-Fidelity IR Signature Models ..............................................21 2.7 Conclusion ...................................................................................................21 3 IR Guided Missiles ............................................................................................. 23 3.1 Introduction..................................................................................................23 3.2 Evolution of Heat Seeking Missiles.............................................................23 3.2.1 First Generation Seekers......................................................................23 3.2.2 Second Generation Seekers..................................................................26 3.2.3 Third Generation Seekers ....................................................................29 3.2.4 Fourth Generation Seekers...................................................................31 3.3 Missile Tracking Techniques.......................................................................33 3.3.1 Gated Video Tracker............................................................................33 3.3.2 Correlation Tracker..............................................................................34 3.4 Missile Guidance .........................................................................................35 3.4.1 Line-of-Sight Guidance .......................................................................35 3.4.2 Homing Guidance................................................................................36 3.4.3 Navigational Guidance.........................................................................36 3.4.4 Compound Guidance ...........................................................................36 3.4.5 Guided Missile Trajectories.................................................................37 3.4.6 Proportional Navigation Guidance ......................................................40 3.4.7 Pursuit Course Guidance......................................................................42 3.5 Missile Controls...........................................................................................43 3.6 Missile Aerodynamics .................................................................................44 3.6.1 Aerodynamics Drag.............................................................................44 3.6.2 Lateral Acceleration of the Missile......................................................45 3.7 Missile Fuses................................................................................................46