In order to study the effect of laser backscatter on the laser semi-active seeker, establish a laser backscatter model to analyze the influence of laser backscattering and calculate how much the safety distance(vertical distance between seeker and laser beam) is required correspondingly. Change the angle of view of the seeker, to analyze the influence of backscatter under different field angles. It was found that the larger the field angle is, the stronger the effect of laser backscattering is. By changing the visibility of the atmosphere and analyzing the effects of backscatter on the seeker under different conditions of atmospheric visibility, it was found that the smaller the atmospheric visibility, the stronger the laser backscattering effect. In short, by changing the angle of view of the seeker and atmospheric visibility, the effect of the backscattering phenomenon can be changed and it requires different safety distances to guarantee the safe launch of missiles correspondingly.
Proc. SPIE. 9142, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics: Optical Imaging, Remote Sensing, and Laser-Matter Interaction 2013
Through the simultaneous photography technology of multi-spectral camera, the remote sensing image is composed of the different spectral of scenes’ electromagnetic spectrum. Having multi-spectral characteristics and rich image information, the remote sensing image is now used widely in many occasions. At the same time, how to achieve the remote sensing image matching rapidly and accurately has been becoming a research focus in the image processing filed. To improve the matching accuracy, this paper, based on the SURF algorithm, uses the Mahalanobis distance affine-invariant character and gets rid of the initial wrong matching points. Numerous experiments were carried out on remote sensing images with geometric distortion such as scale, rotation and so on. The result shows that the effectiveness of the method.
For a class of nonlinear systems with dynamic uncertainties, adaptive stabilization problem is considered in the rate gyroscope of stable platform system. Since the uncertainties are inevitable in the practical model of systems, the robust property of the systems in the presence of parametric uncertainties is important to be considered, such as modeling error, external disturbances, etc. Due to the strong nonlinearity and coupling characteristic of systems, it is difficult to obtain the precise model, and the nonlinearity cannot be cancelled exactly so that the controller performs badly. Adaptive control (AC) can adapt to parameter variations, but it is not applicable to the transition phase. A way to optimize the overall disturbances rejection performance of the AC system in the presence of unknown external disturbances existing in the stable platform system is provided in this paper. According to the construction of stable platform system based on gyroscope stabilized platform, the coordinate systems related to stable platform system are defined, and its mathematical model of stabilized platform is build up. Using the SIMULINK of MATLAB, the model is applied to the computer simulation of the stable platform system with good results. The author designed the control law of velocity-loop respective with the method of continuous correcting net and the AC. The simulation results show that the designed adaptive control law can satisfy the required criterion, it proves that the design method is feasible. In order to compare the above two method efficiently, the author gives the seeker system step response, square wave response especially. Adaptive control law is confirmed to give better tracking performance compared with correcting net control, and a control precision comparable to seeker system and higher robustness to parameter change, despite the simple controller. The research results ensure a wider application of simple AC in real mechanical systems.