A universal and flexible theodolite-camera system for making accurate measurements over large volumes

Abstract Typically, optical measurement systems can achieve high accuracy over a limited volume, or cover a large volume with low accuracy. In this paper, we propose a universal way of integrating a camera with a theodolite to construct a theodolite-camera (TC) measurement system that can make measurements over a large volume with high accuracy. The TC inherits the advantages of high flexibility and precision from theodolite and camera, but it avoids the need to perform elaborate adjustments on the camera and theodolite. The TC provides a universal and flexible approach to the camera-on-theodolite system. We describe three types of TC based separately on: (i) a total station; (ii) a theodolite; and (iii) a general rotation frame. We also propose three corresponding calibration methods for the different TCs. Experiments have been conducted to verify the measuring accuracy of each of the three types of TC.