Jump to ContentJump to Main Navigation
Images and Artefacts of the Ancient World$
Users without a subscription are not able to see the full content.

Alan K. Bowman and Michael Brady

Print publication date: 2005

Print ISBN-13: 9780197262962

Published to British Academy Scholarship Online: January 2012

DOI: 10.5871/bacad/9780197262962.001.0001

Show Summary Details
Page of

PRINTED FROM BRITISH ACADEMY SCHOLARSHIP ONLINE (www.britishacademy.universitypressscholarship.com). (c) Copyright British Academy, 2021. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in BASO for personal use.date: 24 September 2021

Three-Dimensional Laser Imaging in an Archaeological Context

Three-Dimensional Laser Imaging in an Archaeological Context

(p.88) (p.89) Chapter 9 Three-Dimensional Laser Imaging in an Archaeological Context
Images and Artefacts of the Ancient World

Andrew M. Wallace

British Academy

This chapter discusses the strengths and weaknesses of techniques of 3D laser imaging based on time of flight and triangulation. Laser scanning by triangulation is a fully developed technology. Through this method, it is now possible to create faithful 3D datasets from a reasonable range of surface materials. However, laser scanning has some certain drawbacks, restricting their universal applicability. For surfaces with concavities or with intricate details, occlusion may occur due to the necessary separation of the viewpoint between the viewing camera and the laser projector. In addition, the data may be corrupted by false and poor returns caused by variable material reflectance. In the time of flight system, the distance is measured by measuring the time for a focused laser beam to impact on and return from the surface of interest. In this method, the distance is computed and a 3D image can be created if the laser beam is scanned across the target. Although, the time of flight method is a more attractive alternative as it eliminates occlusion, it has disadvantages as well. The time resolution necessary to measure the range to sub-millimetre accuracy is difficult to achieve and the measured time is also affected by the magnitude of the returned signal. In addition to reviewing the pros and cons of this current technology, the chapter also discusses the development of a new approach to time-of-flight laser imaging based on time-correlated single photon counting. This new method has various advantages compared to the old methods. It has the ability to make 3D measurements on distance, poorly reflecting or transparent surfaces.

Keywords:   3D laser imaging, time of flight, triangulation, laser scanning, laser scanning by triangulation, occlusion, material reflectance, time of flight system, laser beam, 3D image

British Academy Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us.