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Displaying 76 - 100 of 121

Recovering Circles and Spheres from Point Data

July 1, 2006
Author(s)
Christoph J. Witzgall, Geraldine Cheok, Anthony J. Kearsley
Methods for fitting circles and spheres to point sets are discussed. LADAR (LAser Detection And Ranging) scanners, in particular, are capable of generating "point clouds" containing the x, y, z coordinates of up to several millions of points reflecting the

Recovering Spheres from 3D Point Data

April 1, 2006
Author(s)
Christoph J. Witzgall, Geraldine Cheok, Anthony J. Kearsley
The National Institute of Standards and Technology is involved in developing standard protocols for the performance evaluation of 3D imaging systems, which include laser scanners and LADARs (LAser Detection and Ranging). A LADAR is an optical device that

Using LADAR to characterize the 3-D shape of aggregates: Preliminary results

March 1, 2006
Author(s)
Edward J. Garboczi, Geraldine S. Cheok, William C. Stone
In previous publications, we have shown how using x-ray computed tomography to obtain the raw 3-D data for the coordinates of the surface, and then converting this raw data into an analytical function for the surface via an expansion in spherical harmonic

Status of the NIST 3D Imaging System Performance Evaluation Facility

January 1, 2006
Author(s)
Geraldine S. Cheok, Alan M. Lytle, Kamel S. Saidi
This paper will present the status of the indoor artifact-based Performance Evaluation Facility at the National Institute of Standards and Technology (NIST) for 3D imaging systems. This facility will be used to develop test protocols and performance

Construction Object Identification from LADAR Scans: An Experimental Study Using I-Beams

December 15, 2005
Author(s)
David E. Gilsinn, Geraldine S. Cheok, Christoph J. Witzgall, Alan M. Lytle
Laser Scanning devices (LADAR for Laser Detection and Ranging) are used in construction projects to capture as-built data. They can rapidly generate large unstructured point clouds. This study describes an experiment in which an I-beam on a concrete floor

Standards Requirements for LADARs?

January 1, 2005
Author(s)
Geraldine S. Cheok, William C. Stone, Alan M. Lytle
This paper presents a discussion of standards requirements for LADAR. Two specific questions are addressed: (1) is there a need for such standards and (2) what types of standards are required? LADAR standards development issues and current standardization

Pose of I-Beams for Construction Site Automation

September 21, 2004
Author(s)
David E. Gilsinn, Geraldine S. Cheok, Alan M. Lytle
Automation of construction processes can result in reduced project costs and increased worker safety. A process that lends itself to automation is the picking and placing of objects. However, determining the pose (position and orientation) of an object is

Triangular Meshing and Volume Determination

July 1, 2004
Author(s)
Christoph J. Witzgall, Geraldine Cheok
Parametric studies are reported for investigating the feasibility and accuracy of calculating volumes from LADAR scans of artifacts. The TIN (=Triangulated Irregular Network) technique was employed to construct surfaces on which the volume calculation was

Performance Evaluation Facility for LADARs

April 12, 2004
Author(s)
Geraldine S. Cheok, William C. Stone
The use and scope of LADAR (laser detection and ranging) applications continues to expand as the technology matures. This growth is reflected in the National Institute of Standards and Technology s (NIST) experience with research into the applications of

TIN Techniques for Data Analysis and Surface Construction

January 1, 2004
Author(s)
Christoph J. Witzgall, Javier Bernal, Geraldine Cheok
This report addresses the task of meshing point clouds by triangulated elevated surfaces referred to as TIN surfaces. It describes the general features of this approach, and refers to prototype TIN software employed at NIST for research into the analysis

Deconvolving LADAR Images Of Bar Codes for Construction Site Object Recognition

October 1, 2003
Author(s)
David E. Gilsinn, Geraldine S. Cheok, Dianne M. O'Leary
This report discusses a general approach to reconstructing ground truth intensity images of bar codes that have been distorted by LADAR optics. The first part of this report describes the experimental data collection of several bar code images along with

Proceedings of the LADAR Calibration Facility Workshop, June 12-13, 2003

October 1, 2003
Author(s)
Geraldine S. Cheok
The use and scope of LADAR applications continues to expand as the technology matures, but standard protocols or procedures for calibrating and testing of LADARs have yet to be developed. While selections of LADAR instruments are generally based on the

Some Issues Relating to Performance Evaluation of LADARs

September 16, 2003
Author(s)
Geraldine S. Cheok, William C. Stone, Christoph J. Witzgall
The use and scope of LADAR applications continues to expand as the technology matures. This growth is reflected in NIST's experience with research into the applications of LADARs for construction, manufacturing, and autonomous vehicle navigation. However

Terrain Characterization from Ground-Based LADAR

September 16, 2003
Author(s)
Christoph J. Witzgall, Geraldine Cheok, David E. Gilsinn
Test runs of Army Research Laboratory s (ARL) autonomous vehicle (Experimental Unmanned Vehicle, XUV) were followed by the acquisition of high resolution scans of selected regions of the test course. These scans were used to i) determine terrain features

A Repository of Sensor Data for Autonomous Driving Research

April 25, 2003
Author(s)
Michael O. Shneier, Tommy Chang, Tsai Hong Hong, Geraldine S. Cheok, Harry A. Scott, Steven Legowik, Alan M. Lytle
We describe a project to collect and disseminate sensor data for autonomous mobility research. Our goals are to provide data of known accuracy and precision to researchers and developers to enable algorithms to be developed using realistically difficult

Ground Truth and Benchmarks for Performance Evaluation

April 25, 2003
Author(s)
A Takeuchi, Michael O. Shneier, Tsai H. Hong, Christopher J. Scrapper Jr, Geraldine Cheok
Progress in algorithm development and transfer of results to practical applications such as military robotics requires the setup of standard tasks, of standard qualitative and quantitative measurements for performance evaluation and validation. Although

Terrain Characterization from Ground-Based LADAR

March 17, 2003
Author(s)
Christoph J. Witzgall, Geraldine S. Cheok, David E. Gilsinn
Test runs of Army Research Laboratory s (ARL) autonomous vehicle (Experimental Unmanned Vehicle, XUV) were followed by the acquisition of high resolution scans of selected regions of the test course. These scans were used to i) determine terrain features

Calibration Experiments of a Laser Scanner

September 1, 2002
Author(s)
Geraldine S. Cheok, Stefan D. Leigh, Andrew L. Rukhin
The potential applications of laser scanners or LADARs (Laser Detection and Ranging) are numerous, and they cross several sectors of the industry construction, large-scale manufacturing, remote sensing, national defense. A LADAR is an instrument which can

Experiences with Point Cloud Registration

September 1, 2002
Author(s)
Christoph J. Witzgall, Geraldine Cheok
The development of LADAR (laser distance and ranging) technology to acquire 3D spatial data made it possible to create 3D models of complex objects. Because an unobstructed line-of-sight is required to capture a point on an object, an individual LADAR scan

Reconstructing Images of Bar Codes for Construction Site Object Recognition

September 1, 2002
Author(s)
David E. Gilsinn, Geraldine S. Cheok, Dianne M. O'Leary
This paper discusses a general approach to reconstructing ground truth intensity images of bar codes that have been distorted by LADARoptics. The first part of this paper describes the experimental data collection of several bar code images along with