In contrast to other existing terrestrial surveying instruments, there are not many benchmark tests available for Terrestrial Laser Scanner (TLS) data quality specifications. This paper presents two possible approaches to the standardization of a TLS point data set. Firstly, the ranging accuracy from an instrument to the object is investigated by comparing measured distances by TLS with those of Total Station (TS). In this case, we use two different slope distances with one being about 25 m and the other, about 50 m in range. Secondly, the comparison of data intensity with six different materials, such as aluminum, a sheet of plywood, resin (black & white), steel (black), and laminate (yellow) is carried out. When comparing the distances measured by TS and those scanned by TLS, the standard deviations (Std.) of differences were found to be about 7 mm (50 m range) and 3 mm (25 m range). In the case of plane-fitting of point clouds, aluminum with white color gave better result than that of others, suggesting that the color of an object affects the intensity value of point clouds. It is expected that these results will contribute to the quality evaluation of TLS point clouds and the selection of standard targets.

This research introduces an improvement plan for the reliability of Global Navigation Satellite System (GNSS) positioning solutions. It should be considered the most suitable methodology in terms of the adjustment and positioning of GNSS in order to maximize the utilization of GNSS applications. Though various studies have been conducted with regards to Bridge Health Monitoring System (BHMS) based on GNSS, the outliers which depend on the signal reception environment could not be considered until now. Since these outliers may be connected to GNSS data collected from major bridge members, which can reduce the reliability of a whole monitoring system through the delivery of false information, they should be detected and eliminated in the previous adjustment stage. In this investigation, the Detection, Identification, Adaptation (DIA) technique was applied and implemented through an algorithm. Moreover, it can be directly applied to GNSS data collected from long span cable stayed bridges and most of outliers were efficiently detected and eliminated simultaneously. By these effects, the reliability of GNSS should be enormously improved. Improvement on GNSS positioning accuracy is directly linked to the safety of bridges itself, and at the same time, the reliability of monitoring systems in terms of the system operation can also be increased.