具有平面结构物体的有限角衍射断层成象
LIMITED ANGLE DIFFRACTION TOMOGRAPHY FOR OBJECTS WITH PLANAR STRUCTURE
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摘要: 本文介绍一个新方法来处理具有平面结构物体的断层成象问题,这个方法称为线性代数法。对于一个具有两层结构的物体,用两个投影就可得到它的断层象,对入射角受限的情况,文中进一步用伪反滤波方法解决病态问题。模拟计算结果表明,对一具有十层平面结构的物体,入射波的角度变化范围被限制在-8°-8°之间,仅用19个投影,就可得到该物体内各层结构的重建象。Abstract: This paper introduces a new algorithm,the linear algebraic method,for reconstructing tomograms of tested objects with planar structure.A computer simulation for reconstru-cting a twolayered object by two projections has been done.For the case of limited angle,we apply a special pseudo-inverse filtering to the ill-posed problem in solving sets of linear algebraic simultaneous equations.Simulation result shows thai a ten-layered object can be reconstructed with only 19 projections having angles ranging from -8° to 8°.