The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B5. Beijing 2008 
and the distance between the range camera and an object, d, is 
estimated as 
d = (2) 
2 2 n 
where is the modulation wavelength. This technology 
allows 3D data to be captured simultaneously, as well as 
removing the requirement to capture two images for processing. 
Therefore, it reduces the necessity to have multiple setups and 
perhaps increases the efficiency for post processing of the 
images. 
Figure 1. Phase shift distance measurement principle for 3D 
range cameras where c(ij) is the detected intensity of the 
returned signal at time Xj and Ax is the temporal sampling 
interval of a 3D range camera. 
2.1 Swissranger SR-3000 Camera 
The Swissranger SR-3000 camera is composed of a 176x144 
pixel CMOS array for which the pixel size and spacing are both 
40pm. The nominal principal distance of the lens is 8mm. 
Several rangefinder system parameters such as the integration 
time (max. 51.2ms) 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 (Mesa Imaging, 2008). 
(a) Mobile phone and Swissranger SR-3000 
(b) Matlab-based interface 
Figure 2. SwissRanger SR-3000 camera. A simple Matlab- 
interface for a SwissRanger SR-3000 was written by Chirstoph 
Weyer and Kwanthar Lim. 
LEDs (Light Emitting Diode) are favoured over conventional 
lasers since they can produce a continuous wave with a high 
modulation frequency and a low price. SwissRanger SR-3000 
has 55 LEDs with a modulation frequency of 20MHz and a 
wavelength of 870nm. The field of view is round about 47.5°x 
39.6° and the special resolution about 1cm in a distance of lm. 
In front of the sensor, an optical band-pass filter is placed in 
order to reduce the impact of background illumination (Oggier 
et al., 2003). More details on the hardware aspects of 
SwissRanger SR-3000 can be found in Lange et al (2000) and 
Oggier et al. (2003). 
2.2 Potential applications 
The use of 3D image capture technology has already been 
implemented in the area of robotics. As shown in Weingarten et 
al. (2004), the preceding model of the SRC is mounted on the 
robot for path planning and objects recognition. Weingarten et 
al. (2004) also demonstrates a 3D camera’s advantage over the 
use of laser scanning when it comes to object recognition and 
stopping distance. 
The automotive industry can use it for determining airbag 
initialisation times and other safety features (Oggier et al. 2005). 
The compact size and low power requirements (Mesa Imaging 
2008) allow the 3D camera to be placed in almost any location, 
as seen in Figure 5 it is mounted near the rear view mirror. This 
3D capture technology would be used to take a snapshot of 
body features for biometrical applications. Laser scanners are 
generally set up for the mapping of body features, but the 3D 
camera provides both 2D and 3D data all within the single 
device at a comparatively cheaper cost and using a much 
smaller device (Oggier et al. 2005). An interactive screen for 
gaming and presentations may be the future technological 
enhancements to replace the use of keyboard and mouse setups 
to favour the implementation of a 3D camera, providing the 
camera becomes available at the consumer level. Development 
of this virtual interaction has started which can be seen in the 
paper by Oggier et al. (2005) where a game of snake being 
played. 
Some applications that may allow the use of such a device in 
this industry include interior building surveys to determine the 
inner dimensions of the room, with a benefit of locating all 
necessary objects with one camera setup instead of using many 
tape measurements. There is a possibility for use in 
underground mining, building on the idea of robotic 
applications to create a remote controlled robot to take images 
of stopes, mineshafts and other hazardous locations, not only 
providing images of the areas, but also allowing 3D models to 
be constructed with the data. 
EXPERIMENT I 
3.1 Experimental setup 
First we conducted a simple experiment for the residual analysis 
of the first order plane fitting with two targets with different 
colours and the size of 50cm by 50cm. The SwissRanger 
SR3000 was mounted on a tripod and the target was mounted 
on a stable heavy weighted stand as shown in Figure 3a. A 
matte white target is shown in Figure 3b. Note that the z-axis of 
the range camera is defined as the direction from the camera to 
the target and so the x- and y- axes of the measured coordinates 
are parallel to the tangential surface of the target accordingly. 
940