“直接线性变换”用于爆破过程高速立体摄影解析的可行性和精度问题

高速摄影作为研究岩土爆破过程的观测手段已有数十年的应用历史,观测内容主要是爆破介质的破裂和运动。研究爆破介质的运动大多是研究其整体的移动—岩(土)体表面的鼓包运动或破碎介质群体的抛掷。

THE AVAILABILITY AND ACCURACY USING DIRECT LINEAR TRANSFORMATIONS FOR THE HIGH-SPEED S1 ERFOPHOTOG R APHY IN EXPLOSION PROCESSES

A Large amount of experiments have demonstrated that direct linear Transformations (DLT) can be used to process the observations of the high-speed stereophotography in explosion processes. An accuracy of 2-3cm can be obtained under the following conditions:photoscale 1:1000; simultaneous exposure frequency 1000Hz;about the same elevation of two cameras; the intersecting angle of two principal optical axes 30?-75? ;better distribution of the contol points.Also the accuracy can be up to the order of a few decimeters even if the elevation difference of two cameras is relatively large,the intersecting angle is as small as 7.5? and no control points in the target area. The intersecting angle has a significant influence on the accuracy of X-coordinates,and the larger elevation difference of the two cameras damages the accuracy of Z-coordinates.Nevertheless,the distribudon of the control points have an importane effect on the accuracy of X-,Y-, and Z-coordinates, as a result,that no control points exist in the explosion area, or control (points are available in one horizontal plane should be avoided.