为了实现对物体的三维形貌绝对测量，避免相位解包裹处理，研究实现了一种基于激光散斑场纵向相关性质的三维形貌绝对测量技术。实验研究了激光散斑场纵向相关性质，利用CCD 相机拍摄不同纵向深度的散斑图，通过相关运算获得散斑图的纵向深度与横向偏移之间的线性关系。利用这一线性关系，实现了对处于激光散斑场中的物体表面到参考面之间高度的绝对测量，三维形貌重建无需相位解包裹处理，并且由于激光散斑场是激光照射毛玻璃形成的，避免了投影数字散斑技术中的透镜投影系统，技术装置简单，操作方便。该技术有望在实践中获得应用。

The longitudinal coherence properties of laser speckles are investigated. The properties are then utilized for three-dimensional (3-D) shape absolute measurement, bringing a feature that phase unwrapping is released. A sequence of speckle images is captured by a CCD camera at different longitudinal positions. The lateral displacement of the speckle can be obtained by calculating the correlation among the speckle images. According to the relationship between the longitudinal length and the lateral displacement, the absolute measurement of height from the object surface to reference plane can be realized. Additionally, the phase unwrapping process is released in data processing. A projection-lens system in the technique of projected digital speckle patterns is also released, because the laser speckle field is generated by a laser which illuminates on a frosted glass. The structure of the system is simple and convenient for implement. This technique is potential to be used in practice.