System and Method for Refining Coordinate-Based Three-Dimensional Images Obtained from a Three-Dimensional Measurement System

Abstract

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target and generate a three-dimensional image of the target. The system may refine the three-dimensional image by reducing the stochastic components in the transformation parameters between video frame times.

What is claimed is: 
     
         1 . A system for refining 3D images, the system comprising:
 a lidar subsystem configured to direct at least two beams toward the target, generate a first set of line scan 3D measurements for a plurality of points on the target for a first beam of the at least two beams, and generate a second set of overscan 3D measurements for the plurality of points on the target for a second beam of the at least two beams;   a video subsystem configured to provide a set of the video frames of the target; and   a processor configured to:
 receive, from the lidar subsystem, the line scan 3D measurements and the set of overscan 3D measurements, 
 receive, from the video subsystem, the a set of the video frames of the target, 
 determine, at each frame time, a plurality of Δz offsets between pre over-scan measurements and the line scan 3D measurements and post over-scan measurements and the line scan 3D measurements, and 
 adjust a plurality of transformation parameters based on a least square optimization. 
   
     
     
         2 . A system for refining 3D images, the system comprising:
 a lidar subsystem configured to direct at least two beams toward the target, and generate a plurality of 3D measurements for a plurality of points on the target for each beam of the at least two beams;   a video subsystem configured to provide the set of the video frames of the target; and   a processor configured to:
 receive, from the lidar subsystem, the plurality of 3D measurements, 
 receive, from the video subsystem, the set of the video frames of the target, 
 transform each of the set of video frames to a next frame time and a previous frame time to generate a set of transformed video frames, 
 compare a pixel intensity of the transformed video frames, 
 determine one or more video offsets between the transformed video frames, and 
 using the determined one or more offsets, determine corrections to the transformation parameters based on the multi-frame least square optimization.