一种新的叠栅层析迭代算法

利用叠栅层析具有的测量动态范围大,对震动环境不敏感的特点,从其偏折原理的本质出发,提出一种利用代数迭代法来重建三维流场的叠栅层析重建算法。在此基础上进行了双峰函数的模拟实验,分别进行了6方向,12方向以及叠加高斯噪声的12方向的数值重建,并在相同条件下与滤波反投影方法和对偏折投影数据积分的代数迭代算法这两种已有的叠栅层析重建算法进行了比较,同时用该新算法结合属性矩阵对包含遮挡物的模拟场进行重建。对比重建结果,本算法具有较强的抗噪声能力,并且对非完全数据下的层析重建也有较好的处理效果。

A Novel Iterative Algorithm for Moiré Tomography

It is known that moiré tomography is applicable in widely changed flow fields and not sensitive to heavy vibrative conditions. So a new algebraic iterative algorithm developed from the essence of moiré deflectometry is presented to reconstruct three-dimensional flow fields. The algorithm is demonstrated by mapping a double-hump simulated temperature field by projections with 6 directions, 12 directions and 12 directions with Gaussian error added separately. Under same conditions, two other available tomography reconstruction algorithms, the filter back-projection algorithm and the algebraic reconstruction algorithm with integral operation along the deflectometry-projection data, are used to reconstruct the field. A simulation with an opaque is also made with the new algorithm. The reconstruction results show the new algorithm not only has strong ability of noise immunity, but also can handle reconstructions with incomplete data quite well.