Abstract: Method (300) for registration of two or more of frames of three dimensional (3D) point cloud data (200-i, 200-j). A density image for each of the first frame (frame i) and the second frame (frame j) is used to obtain the translation between the images and thus image-to-image point correspondence. Correspondence for each adjacent frame is determined using correlation of the ‘filtered density’ images. The translation vector or vectors are used to perform a coarse registration of the 3D point cloud data in one or more of the XY plane and the Z direction. The method also includes a fine registration process applied to the 3D point cloud data (200-i, 200-j). Corresponding transformations between frames (not just adjacent frames) are accumulated and used in a ‘global’ optimization routine that seeks to find the best translation, rotation, and scale parameters that satisfy all frame displacements.

Abstract: Method for providing a color representation of three-dimensional range data (200) for improved visualization and interpretation. The method also includes selectively determining respective values of the hue (402), saturation (404), and intensity (406) in accordance with a color map (FIG. 5, 6) for mapping the hue, saturation, and intensity to an altitude coordinate of the three-dimensional range data. The color map is defined so that values for the saturation and the intensity have a first peak value at a first predetermined altitude approximately corresponding to an upper height limit (308) of a predetermined target height range (306). Values defined for the saturation and the intensity have a second peak at a second predetermined altitude (310) corresponding to an approximate anticipated height of tree tops within a natural scene.