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EXTENSIVE METRIC PERFORMANCE EVALUATION OF A 3D RANGE CAMERA 
Christoph A. Weyer 3 , Kwang-Ho Bae 1-2 ’*, Kwanthar Lim 1 and Derek D. Lichti 4 
‘Western Australian Centre for Geodesy & The Institute for Geoscience Research, Department of Spatial Sciences, 
Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia 
Cooperative Research Centre for Spatial Information (CRC-SI), Australia 
3 Institut fur Photogrammetrie und Fernerkundung, Universität Karlsruhe (TH), Karlsruhe, Germany 
department of Geomatics Engineering and Centre for Bioengineering Research and Education, University of 
Calgary, Calgary, Canada 
- k.h.bae@curtin.edu.au, - weychr@gik.uni-karlsruhe.de, - kwanthar.lim@student.curtin.edu.au, - ddlichti@ucalgary.ca 
Commission V, WG 3 
KEY WORDS: Range camera, Calibration, Measurement error, Performance analysis 
ABSTRACT: 
Three dimensional (3D) range cameras measure 3D point clouds and intensity information of objects using time-of-flight methods 
with a CMOS/CCD array. Their emerging applications are security, surveillance, bio-mechanics and so on. Since they comprise a 
CMOS/CCD array, a nearest-neighbor search for individual points is not necessary, which can increase the efficiency in estimating 
the geometric properties of objects. This fact leads us to broaden the application areas of 3D range cameras to real-time and dynamic 
applications such as mobile mapping and vehicle navigation. This paper presents extensive metric performance tests of a 3D range 
camera (SwissRanger SR-3000). It is composed of a 176x144 pixel CMOS array for which the pixel size and spacing are both 40um. 
The nominal principal distance of the lens is 8mm. Several rangefinder system parameters such as the integration time and the 
modulation frequency can be set by the user. For example, the shorter integration time is maximising the signal-to-noise ratio. In 
addition, the maximum unambiguous range is 7.5m with the modulation frequency of 20MHz. 
INTRODUCTION 
Three dimensional (3D) range cameras measure 3D point 
clouds and intensity information of objects using time-of-flight 
methods with a CMOS/CCD array. Their emerging applications 
are security, surveillance, bio-mechanics and so on. Since they 
comprise an array of small detectors, a nearest-neighbor search 
for individual points is not necessary for the case of single 
instrument, which can increase the efficiency in estimating the 
geometric properties of objects. This fact leads us to broaden 
the application areas of 3D range cameras to real-time and 
dynamic applications such as mobile mapping and vehicle 
navigation. 
It is a new and largely untested technology showing potential in 
industrial applications. In general, a laser scanner would be 
used to obtain 3D coordinates of an object, which may be 
unsuitable in conditions having spatial and temporal limitations 
and financial constraints. Therefore, a range camera may 
provide a more suitable alternative, taking for example the 
automotive industry where 3D range cameras’ size allows it to 
be mounted in the interior of the car to observe passenger 
position as part of the airbag sensing systems (Oggier et al., 
2005). In order to ensure a good metric performance in these 
applications, it is necessary to evaluate the camera to highlight 
the areas of promise and areas that need further development, 
such as calibration and error modelling. Errors need to be 
identified by first conducting experiments to analyse basic 
elements of the camera used in those industries, beginning here 
with its accuracy and precision. 
This paper provides a general overview of this new instrument 
and extensive metric performance tests of a 3D range camera, 
SwissRanger SR-3000 (Mesa Imaging, 2008). 
BACKGROUND 
Images from current cameras display only two dimensions (2D), 
lying in the x and y coordinate space. In order to obtain three- 
dimensional (3D) information, photogrammetry techniques 
using two images of the same place from differing perspectives 
will allow 3D coordinates to be computed. 
There are three types of non-contact distance measurement 
methods such as triangulation, interferometry and time-of-flight 
(Buttgen et al., 2005; Gordon, 2005). A 3D range camera used 
in this study, SwissRanger SR-3000 (Mesa Imaging, 2008), is 
based on the time-of-flight principle using a continuous wave 
modulation (Buttgen et al., 2005; Kahlmann et al., 2006; Karel 
et al., 2007). The continuous wave modulation system is 
frequently used on 3D range cameras. As shown in Figure 1, a 
sinusoidal signal is transmitted toward the scenery or an object, 
which is reflected and received by a sensor, such as a charge- 
coupled device (CCD) array. The range is then estimated using 
the phase differences between the emitted and received 
sinusoidal signals. The phase shift, <p, between the transmitting 
and returning signal is given as 
<p = tan 
c(t 3 ) - c(r,) 
c@ 0 ) - c(t 2 ) 
(1) 
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