共查询到16条相似文献,搜索用时 187 毫秒
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提高彩色大面阵航空遥感相机地面分辨力需设计像移补偿环节以消除工作时CCD像面的像移,本文在分析航空遥感器4种像移补偿方式及像移补偿机构设计原则的基础上,针对某航空遥感器的要求设计了一种前向像移补偿机构,利用等径共轭凸轮机构将电机旋转转化为直线运动,并配合精密直线导轨约束运动自由度。具有传动简单,精度较高的优点,可有效的避免传动误差。分析了原动件输入速度波动、制造误差对像移补偿残差的影响,并对像移补偿总体效果进行了评价。试验数据及数据分析表明,像移补偿机构的补偿残差小到600μm/s,动态目标发生器及外场航拍图像良好,满足使用要求。 相似文献
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飞机姿态变化是影响航空相机成像质量的关键因素,尤其是飞机进行大坡度转弯将影响航空相机照相分辨率和重叠率。采用公式推理、坐标旋转变换等方法详细分析了飞机大坡度转弯对相机照相分辨率和重叠率的影响,并以摆扫型全景相机为例,给出了飞机大坡度转弯时相机的像移模型,分析结果表明:飞机大坡度转弯过程中相机产生的最大前向像移量接近4个像素,需要进行像移补偿;而垂直飞行方向上的最大像移量小于1/8像元,对成像分辨率影响不大。依据分析结果对像移模型进行了简化,为像移补偿提供了理论依据。针对飞机大坡度转弯对照相重叠率的影响,提出了依据转弯半径和转弯角速率调整曝光时间的方法加以解决。上述分析为摆扫相机在大坡度转弯时获取高质量图像提供了理论依据。 相似文献
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对航空CCD相机机械拼接焦面搭接区域内由于2个CCD像移量不同导致的像点错位问题进行了分析。首先,根据航空中心投影成像的几何关系,给出了正直摄影时地面起伏导致的搭接区相对像移量,然后,由共线方程出发,建立了搭接区相对像移量的数学模型,分析了载机姿态、地面起伏、CCD拼接距离等因素对搭接区相对像移量的影响。最后,根据建立的数学模型及工程应用实例选取了补偿载机姿态变化的稳定平台,并给出了搭接区相对像移量的数值分析结果。本文建立的搭接区数学模型对采用机械拼接方案的航空相机具有一定的工程和应用意义。 相似文献
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航空相机航向方向的像移包括飞机前向飞行引起的前向像移以及飞机姿态(俯仰/偏航)在航向方向的分量。本文以某摆扫型航空相机为例,分析了利用扫描反射镜进行前向方向像移补偿的原理,扫描反射镜以二分之一的前向方向像移角速度的速度旋转即可补偿前向像移。文中探讨了两种控制方案,第一种方案将陀螺直接安装在反射镜上,结构设计简单,但控制电路较复杂,且需增加一个陀螺;第二种方案提出利用机械系统增加2:1速比的方法,可以节省成本,且不增加控制系统的难度。经过实际工程实践证明,第二种方案简单实用,可以满足相机补偿要求。 相似文献
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遥感相机像移速度的滤波处理 总被引:2,自引:0,他引:2
在遥感相机对地面目标摄影的过程中 ,由于地面目标在相机象面上的象是运动的 ,即存在象移 ,这将导致相机分辨力下降。为获得较高的动态照象分辨力 ,必须对象移进行补偿 ,而补偿的关键是准确地获得当前的象移速度。本文采用统计实验方法 ,分析了采用计算法得到的象移速度的分布特性 ,给出了实用的象移速度滤波预处理、卡尔曼滤波、野值剔除方法。仿真结果表明 ,所给出的滤波处理方法效果明显 ,简单实用 相似文献
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G. C. Brock 《成像科学杂志》2013,61(3)
The lecture deals with the subject of image qualIty in air photography, exciuding mapping techniques as such. Though pOInting out that ‘air photography’ as a technique includes the aeroplane ond ,ts navigation, II concentrates on aspects of general photographic interest. The fundomentol needs and problems of oir photogrophy were seen by L. P, Clerc in a Trail- Taylor Memorial Lecture delivered ,n 1921. Progress since that time hos been brought about by taking advantage of technological advance in sensitive materials, optics electronics etc. rather than by any fundamenlIy new ideas. Panchromatic emulSIons are (aster, more hIghly colour-sensitized and keep beller. Improvements in their physical hardness have ollowed the development of rapid processing techniques. A machine developed by the Royal Aircraft Establishment processes standard types of 70 mm. (11m (e.g., HP. 3.) at 80 (I. per minute for a power consumption of Six kilowatts. Size is 5 ft, 6 in. long by 5 ft. 810. high. Solutions at 110 Fare applied by high pressure ets; dryto- day time is two minutes with washing to commercial standalds. Emulsions having the property 0 constant speed whIle controst varies with development time would be more useful than current emulsions in which the speed varies while contrast remains substantially unchanged. The luminous density relation for effective photographic light versus solar attitude can give serious over-exposure in air photography of desert areas, and it has been shown by photography and photometry that exposure settings for such areas should be based on the illumination on the horizontal plane, which was abandoned for ground photography several years ago. Lenses, particularly wide-angle lenses for survey, have been greatly Improved, both in definlt,on and 10 illumination off-axis: thus it Is possible and pro(ltable to use slower flims with consequently improved angular resolution. Examples are shown of the effect of lighting angles, which though out of control are very Important ;n air photography. The alfcraft camera is briefly compared with lhe eye and the television camera, It Is less sensitive than eIther, but records more IOformation and has the advantage of buit-,n slorage. The latest wide-angie survey cameras cover 120, comparable with the cover of the eyes, at slightly lower angular resolution. Brief reference is made to the coming substitution of resolution tests by “frequency response” or “contrasl-lransfer” methods. Experimental evidence is given of the value of such methods ,n predicting accurately the effect of movement on image quality. 相似文献
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We suggest what we believe is a new three-dimensional (3-D) camera system for integral photography. Our method enables high-resolution 3-D imaging. In contrast to conventional integral photography, a moving microlens array (MLA) and a low-resolution camera are used. The intensity distribution in the MLA image plane is sampled sequentially by use of a pinhole array. The inversion problem from pseudoscopic to orthoscopic images is dealt with by electronic means. The new method is suitable for real-time 3-D imaging. We verified the new method experimentally. Integral photographs with a resolution of 3760 pixels x 2560 pixels (188 x 128 element images) are presented. 相似文献
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提出了基于长时运动滤波和图象仿射变换的数字图象稳定模型,在PIPE机上完成了一个数字图象的实时稳定系统。关键技术包括图象运动检测方法、运动滤波方法,消除抖动的运动补偿方法以及从色素到象素的图象校正算法。 相似文献