Publication Date:
2013-10-02
Description:
ABSTRACT Terrestrial laser scanning is the current technique of choice for acquiring high resolution topographic data at the site scale (i.e. over 10s to 100 s of meters), for accurate volume measurements or process modelling. However, in regions of complex topography with multiple local horizons, restricted lines of sight significantly hinder use of such tripod-based instruments by requiring multiple setups to achieve full coverage of the area. We demonstrate a novel hand-held laser scanning technique that offers particular promise for site-scale topographic surveys of complex environments. To carry out a survey, the hand-held mobile laser scanner (HMLS) is walked across a site, mapping around the surveyor continuously en-route. We assess the accuracy of HMLS data by comparing survey results from an eroding coastal cliff site with those acquired by a state-of-the-art terrestrial laser scanner (TLS) and also with the results of a photo-survey, processed by structure-from-motion and multi-view stereo (SfM-MVS) algorithms. HMLS data are shown to have an RMS difference to the benchmark TLS data of 20 mm, not dissimilar to that of the SfM-MVS survey (18 mm). The efficiency of the HMLS system in complex terrain is demonstrated by acquiring topographic data covering ~780 m 2 of salt-marsh gullies, with a mean point spacing of 4.4 cm, in ~6 minutes. We estimate that HMLS surveying of gullies is approximately forty times faster than using a TLS and six times faster than using SfM-MVS. This article is protected by copyright. All rights reserved.
Print ISSN:
0197-9337
Electronic ISSN:
1096-9837
Topics:
Geography
,
Geosciences
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