For target detection of hyperspectral imagery, this paper proposes a K - L transformation method based on spectral characteristics is introduced to extract the significant profile target. The significant characteristics represents the significant information, spatial distribution of the significant region and correlation information in the image. Profile features can reflect the correlation information of the background and target in the significant region from a whole. Target detection can be realized by classifying these regions. Since the method above could not accurately obtain targets like human visual ability and detect several regions in one target, a kind of an algorithm based on difference will be put forward in this paper. Firstly, the background for comparison must be selected according to the original image. Then, the object-of-interest could be obtained by comparing the difference between the image and the background template. Furthermore, multiple targets in the same region can be marked respectively by the difference method.
The aircraft landing signal lamp is a kind of optical equipment which provides the pilot with visual landing optical indication. It is installed on the apron of the airport. The aircraft landing signal lamp is usually installed on the aircraft landing sign line. To ensure the safety of aircraft taking off and landing, the height of the lamp after installation should not exceed 30mm. Aircraft landing lights need to provide 360 degrees of horizontal direction, 7 degrees to 90 degrees of vertical direction, and the power should not be too large, therefore, the optical system is required to have a reasonable light distribution curve, high light utilization rate. Because pilots are equipped with night vision equipment at night, landing lights need to provide a near-infrared light signal as well as visible light. To make aircraft take off and land safer, this paper designs an optical system of aircraft landing signal light based on the principle of light guiding optics, which makes the upper surface of the lamp flush with the mounting surface. The height of the lamp after installation is 0mm. The optical system consists of LED integrated surface light source and light guiding glass column. Integrated surface light source integrates visible light LED chip and near infrared LED chip together. To make the light Angle larger and the light distribution curve more reasonable, the upper surface of the light guide glass column is in the form of microlens array. At the end of this paper, a photo of the optical indication effect of aircraft landing signal light is given.
The washing floodlight is a sort of optoelectronic equipment for the use on vessels which contain helipad, designed as a visual landing aid for the helicopter. Usually the washing floodlight is installed directly on the edge of deck, while the installation site should not be too high, normally lower than 350mm is recommended. In addition, since floodlight generally provides high and relative uniform illumination for a larger deck surface, it is necessary to have a reasonable light intensity distribution, high light intensity and high light energy efficiency. Meanwhile, the floodlight need to provide not only visible light but also infrared illumination to coordinate with night vision goggle. This paper provides a washing floodlight design with high light intensity and high average illumination. The illumination optical system consists of two separate portions, namely refraction and reflective illumination optical system. The refraction illumination optical system is a cylindrical lens with free-form surface, the upper part of lens is responsible for small angle illumination (about 0° to -5 ° in the vertical direction), while the nether part is responsible for large angle illumination (about -5 ° to -30 °in the vertical direction). Besides, the reflection illumination optical system is a cylindrical mirror with scaly conicoid reflection surfaces rather than traditional smooth quadric surface, which can improve the ability to control light, providing a larger angle of uniform illumination. In the later part of this paper, the illumination performance with 8 washing floodlight is simulated, and the illumination performance picture of a real washing floodlight is given.
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