Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B5, 557-563, 2016
https://doi.org/10.5194/isprs-archives-XLI-B5-557-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
 
15 Jun 2016
AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS
Mustafa Ozendi1, Devrim Akca2, and Hรผseyin Topan1 1BEU, Department of Geomatics Engineering, 67100 Zonguldak, Turkey
2ISIK University, Department of Civil Engineering, 34980 Sile, Istanbul, Turkey
Keywords: TLS, reflectance, incidence angle, range, error ellipsoid, anisotropic, error model Abstract. The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (๐œŽ๐œƒ) and vertical (๐œŽ๐›ผ) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as ๐œŽ๐œƒ=ยฑ36.6๐‘๐‘ and ๐œŽ๐›ผ=ยฑ17.8๐‘๐‘, respectively. On the other hand, a priori precision of the range observation (๐œŽ๐œŒ) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as ๐œŽ๐œŒ=ยฑ2โˆ’12 ๐‘š๐‘š for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.
Conference paper (PDF, 1911 KB)


Citation: Ozendi, M., Akca, D., and Topan, H.: AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS, Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B5, 557-563, https://doi.org/10.5194/isprs-archives-XLI-B5-557-2016, 2016.

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