Study Of Key Technology Of Laser Directional Infrared Countermeasures System

With the development of infrared imaging detector and its technology, theguidance accuracy of missile was enhanced by the target passive infrared homingtechnique at the end phase. Hence, some big targets, such as tank, cargo-transport planeand ship have been taken into the more and more dangerous field. It is very useful todevelop the photoelectric countermeasures on these missiles. As one of the effectivemethods, technique of directional infrared laser countermeasures is one of the mostvaluable techniques to countermeasure enemy's missiles.Main principle of laser directional infrared countermeasures (DIRCM) istransmitting laser beam onto detector and jamming, blinding, damaging the detector.DIRCM system has two operating mode, that is, open loop and close loop. The systemwith close loop operation mode includes several sub-systems as followed. They arepower system, central control system, laser system, target acquiring, tracking andpointing system, laser transmitter and receiver, system support platform, et al. As awhole, DIRCM system has some advantages such as small dimensions, lower weight,far range, short response time, etc. It can also operate long time and is very suitable tobe applied as a jamming way. There are some key-techniques to be concerned withinDIRCM system, such as, pulse laser jamming technique and target detection andrecognition technique, etc. The mission of this dissertation is about the key-technique ofpulse laser jamming, target detection and recognition and simulation of small targetmotion along two dimensions.The main studies of this dissertation are listed below.(1) The studies of Laser Directional InfraRed CounterMeasures (DIRCM) aremade systematically. Under the theoretical researches, it is an independentwork to establish an experimental system to do the experimental researches onkey technique of DIRCM. The hardware-in-loop simulations and systemverifications of technology of target detection and recognition, laser jammingtechnique and system control technique can be well done by the system. It isthe base to develop future DIRCM system. (2) In the field of target detection and recognition, a law of minimum image ofextended target is presented. It gives clear definition on spot target andextended target. And it will made references for engineering design of system.(3) Analyses of application of 'cat eye effect' in the field of target detection andrecognition are made. And the relevant experiments are also made.(4) A novel simulation system of small target's two-dimension motion isestablished. The laser spot on the screen simulates the small target. Throughthe control of the motion of laser spot, the motion simulation of small targetcan be made. The simulation system has a compact geometry, low cost and canbe easily updated. It is very feasible for the verification of target acquiring,tracking and pointing system.(5) In the field of laser jamming technology, it is the first time to present the'fringe astigmatic light jamming' method. And the relevant experiments aremade. And it is the first time to achieve the laser jamming experiments on thetarget detection and recognition arithmetic, that is, 'inter-frame differencealgorithm'. With this technique, the target acquiring, tracking system issuccessfully jammed. It supports one feasible method for the DIRCMtechnology.