Surveying Through Solid Walls

Published

June 8, 1997

Author(s)

William C. Stone

Abstract

A good metrology system in the automated environment must (1) measure the three dimensional position and attitude of any component to a reasonable degree of accuracy; (2) acquire these data fairly rapidly; and (3) be capable of making reliable measurements anywhere on site. A significant limitation for existing surveying systems (including GPS and laser based technologies) is the requirement for direct line-of-sight between the reference and roving surveying elements. Construction sites, as a rule, are highly unstructured environments and clutter is the norm. Recent fundamental research has been undertaken at NIST to develop a real-time Non-Line-of-Sight measurement system capable of tracking to 10 mm accuracy despite the presence of walls, ceilings, floors, and other obstructions. The new system determines the distance from a series of reference transmitters which broadcast pulse-synthesized baseband electromagnetic signals. Digital signal processing techniques are used to recover the time of flight (and hence distance) and to compensate for errors introduced as a result of material penetration and re-transmission of the signal. Results are disucssed.

Proceedings Title

14th International Symposium

Conference Dates

June 8-11, 1997

Conference Location

Pittsburgh, PA

Conference Title

Automation and Robotics in Construction

Pub Type

Conferences

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Keywords

walls, electromagnetic wave propagation, metrology, non-line-of-sight, signal attenuation, spread spectrum radar, surveying, wireless communications

Citation

Stone, W. (1997), Surveying Through Solid Walls, 14th International Symposium, Pittsburgh, PA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909362 (Accessed October 11, 2025)