Accurate Measurements with Image-Assisted Total Stations and Their Prerequisites

作者：Ehrhart Matthias^*; Lienhart Werner

来源：Journal of Surveying Engineering-ASCE, 2017, 143(2): UNSP 04016024.

DOI：10.1061/(ASCE)SU.1943-5428.0000208

• Image-assisted total station (IATS)
• Gnomonic projection
• Camera calibration
• Ellipse center offset
• Warm-up effects
• Geodetic network measurements

Video theodolites were used in the 1980s for highly accurate, automated measurements. However, they disappeared from the market and research on these instruments was done by only a few institutions using self-made prototypes. Because of the release of new-generation image-assisted total stations (IATS) by different manufacturers since 2004, these instruments have become relevant again for broader user groups. In this article, different error sources that occur when working with an IATS are assessed. The theoretical origins of these errors are discussed, their dependence on the measurement geometry is worked out, and strategies for avoidance and modeling are provided. In experimental geodetic network measurements, the impact of the different error sources on the results are evaluated. With standard deviations of a few 0.01 mm for the estimated three-dimensional (3D) coordinates, it is demonstrated that the telescope camera of a modern IATS can be used as a highly accurate measurement sensor.

• 出版日期2017-5