Derek Lichti

Dr. Derek Lichti

Department of Geomatics Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2007 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Closed access
DLDerek Lichti
Derek Lichti

1 October 2006 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Closed access
JSJan Skaloud
Jan Skaloud
DLDerek Lichti
Derek Lichti

1 May 2007 in Journal of Surveying Engineering
Verified
Journal Article
Closed access
SGStuart J. Gordon
Stuart J. Gordon
DLDerek Lichti
Derek Lichti
A modeling strategy has been developed that permits coarse-precision terrestrial laser scanner observations to be used to accurately measure vertical deflections of deforming beams. The model is developed from fundamental beam-deflection equations and implemented using a weighted-constraint, least-squares curve-fitting approach. After the solution is computed, a statistical testing procedure is applied to assess the level of contribution of each of the estimated parameters in the model and identify redundant terms for removal. Two terrestrial laser scanners (TLSs) are employed to test the approach by measuring the vertical displacement of beams undergoing controlled loading for which the magnitude of displacements was at the 2–50 mm level. Results demonstrate that the modeled TLS data, when compared to conventional monitoring equipment, such as convergent digital photogrammetry and contact sensors, achieved an accuracy that is up to 20 times higher than the TLS’s coordinate precision, thus underscoring th...

22 June 2010 in Remote Sensing
Verified
Journal Article
Open access
PDF file
CGCraig Glennie
Craig Glennie
DLDerek Lichti
Derek Lichti
The static calibration and analysis of the Velodyne HDL-64E S2 scanning LiDAR system is presented and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is derived and discussed. A planar feature based least squares adjustment approach is presented and utilized in a minimally constrained network in order to derive an optimal solution for the laser’s internal calibration parameters. Finally, the results of the adjustment along with a detailed examination of the adjustment residuals are given. A three-fold improvement in the planar misclosure residual RMSE over the standard factory calibration model was achieved by the proposed calibration. Results also suggest that there may still be some unmodelled distortions in the range measurements from the scanner. However, despite this, the overall precision of the adjusted laser scanner data appears to make it a viable choice for high accuracy mobile scanning applications.

1 January 2008 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Closed access
KBKwang-Ho Bae
Kwang-Ho Bae
DLDerek Lichti
Derek Lichti

25 April 2006 in The Photogrammetric Record
Verified
Journal Article
Closed access
PDF file
DLDerek Lichti
Derek Lichti
SJSonam Jamtsho
Sonam Jamtsho