Huang, Yi Dong
ORIENTATION OF IMAGES CAPTURED WITH VIDEO-THEODOLITES
Yi Dong HUANG, Dongbin CHEN
University of East London, School of Surveying, UK
Y.Huang@uel.ac.uk
Working Group III/1
KEY WORDS: Videotheodolite, Orientation
ABSTRACT
Images can be directly oriented without registration of corresponding points or control points if they are taken with a
calibrated video-theodolite. The conditions are that the video-theodolite is calibrated for the camera-to-theodolite
relationship and appropriate theodolite observation procedures are followed to orient the theodolite. This paper
describes the detail of the coordinate relationship between camera, theodolite and the world, calibration requirements,
and different methods for theodolite orientation. A new pair of collinearity equations are derived and used in an
experiment to relatively orient two video-theodolite stations via image measurement. The new collinearity equations are
also applicable to bundle adjustment of data acquired with video-theodolites.
1 INTRODUCTION
Video-theodolites are increasingly used for image data acquisition for measurement and visualisation purposes. They
have been used to capture oriented panoramic images for facility management in the oil and gas processing and nuclear
generation plants (Chapman et al 1994), to capture oriented image sequences to track moving objects and human
motion (Kakiuchi et al. 1999, Anai et al. 1999) and to visualise laser scan surface models with rendered images (Gong
et al 1999),
There are many unique advantages of using video-theodolites. These include the capability of acquiring high resolution
mosaic panoramic images, the ease of providing accurate direct orientation parameters for the images captured, video-
guided theodolite surveying. Because of these advantages, video-theodolites have a great potential for wider application
(Huang 1992).
Calibration and orientation are two fundamental problems that need effective solutions for effective application of
video-theodolites. Calibration is to determine the camera interior orienation parameters and the six parameters that
describe the camera position and attitude with respect to the theodolite. Orientation refers to the process of determining
the positions and attitudes of video-theodolite stations relative to each other and to a specified object coordinate system.
Some of the author's previous papers have explained and demonstrated an effective method for calibration (Huang et al
1989). This paper is set out to investigate the orientation problem, aimed to provide formulations for practical use and
further development.
2. MEASUEREMENT PRINCIPLES OF VIDEO-THEODOLITES
2.1 Definition of Video-Theodolites
The video-theodolite is an instrument which is constructed by attaching or integrating a video (or digital) camera rigidly to
the telescope of a theodolite such that the camera and the telescope can rotate together about both the theodolite axes. The
camera and the theodolite are optically independent of each other so that the camera can take images and the theodolite can
still measure angles as usual, but both are connected to the host computer with image processor mounted.
A video-theodolite can have several working modes. 1) the theodolite mode, where the theodolite is used as the major
measuring device, and the video camera is used to provide a visual user interface and/or an artificial eye for target
identification. 2) the camera mode, where the video camera is the major measuring device and work on
photogrammetric principles, and the theodolite is used to provide precise direct orientation for the camera.
388 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.
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