Influence of surface reflectivity on reflectorless electronic distance measurement and terrestrial laser scanning
-
Miriam Zámečníková
,
Andreas Wieser
Abstract
The uncertainty of electronic distance measurement to surfaces rather than to dedicated precisionre flectors (reflectorless EDM) is afected by the entire system comprising instrument, atmosphere and surface. The impact of the latter is significant for applications like geodetic monitoring, high-precision surface modelling or laser scanner self-calibration. Nevertheless, it has not yet received sufficient attention and is not well understood. We have carried out an experimental investigation of the impact of surface reflectivity on the distance measurements of a terrestrial laser scanner. The investigation helps to clarify (i)whether variations of reflectivity cause systematic deviations of reflectorless EDM, and (ii) if so, whether it is possible and worth modelling these deviations. The results show that differences in reflectivity may actually cause systematic deviations of a few mm with diffusely re- flecting surfaces and even more with directionally reflecting ones. Using abivariate quadratic polynomial we were able to approximate these deviations as a function of measured distance and measured signal strength alone. Using this approximation to predict corrections, the deviations of the measurements could be reduced by about 70% in our experiment.We conclude that there is a systematic effect of surface reflectivity (or equivalently received signal strength) on the distance measurement and that it is possible to model and predict this effect. Integration into laser scanner calibration models may be beneficial for high precision applications. The results may apply to a broad range of instruments, not only to the specific laser scanner used herein.
© 2014 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Masthead
- Editorial
- Editorial to the Special Edition of the JAG on Engineering Geodesy
- Research Articles
- A Tale of Five Bridges; the use of GNSS for Monitoring the Deflections of Bridges
- Optimal GPS/accelerometer integration algorithm for monitoring the vertical structural dynamics
- Wavelet De-noising of GNSS Based Bridge Health Monitoring Data
- Utility Theory as a Method to Minimise the Risk in Deformation Analysis Decisions
- Aiming at self-calibration of terrestrial laser scanners using only one single object and one single scan
- Influence of surface reflectivity on reflectorless electronic distance measurement and terrestrial laser scanning
- Experts View
- Engineering Geodesy - Definition and Core Competencies
Articles in the same Issue
- Masthead
- Editorial
- Editorial to the Special Edition of the JAG on Engineering Geodesy
- Research Articles
- A Tale of Five Bridges; the use of GNSS for Monitoring the Deflections of Bridges
- Optimal GPS/accelerometer integration algorithm for monitoring the vertical structural dynamics
- Wavelet De-noising of GNSS Based Bridge Health Monitoring Data
- Utility Theory as a Method to Minimise the Risk in Deformation Analysis Decisions
- Aiming at self-calibration of terrestrial laser scanners using only one single object and one single scan
- Influence of surface reflectivity on reflectorless electronic distance measurement and terrestrial laser scanning
- Experts View
- Engineering Geodesy - Definition and Core Competencies
