Surveillance with automated positioning and tracking of subjects and vehicles in 3D is desired in many defence
and security applications. Camera systems with stereo or multiple cameras are often used for 3D positioning.
In such systems, accurate camera calibration is needed to obtain a reliable 3D position estimate. There is also a
need for automated camera calibration to facilitate fast deployment of semi-mobile multi-camera 3D positioning
systems. In this paper we investigate a method for automatic calibration of the extrinsic camera parameters
(relative camera pose and orientation) of a multi-camera positioning system. It is based on estimation of the
essential matrix between each camera pair using the 5-point method for intrinsically calibrated cameras. The
method is compared to a manual calibration method using real HD video data from a field trial with a multicamera
positioning system. The method is also evaluated on simulated data from a stereo camera model. The
results show that the reprojection error of the automated camera calibration method is close to or smaller than
the error for the manual calibration method and that the automated calibration method can replace the manual
calibration.
Stand-off THz imaging to detect concealed treats is a coming technique for security applications. A THz sensor
can provide high resolution 3D imagery of a scene. However, efficient scene scanning and management of the
THz sensor is a challenging task due to the limited field of view of the sensor and physical scanning limitations.
In this paper we discuss the requirements on a scene scanning solution and present a scene scanning technique
using a multi-camera system with 3D positioning capabilities. A visual hull method is used to position subjects
in the scene. The presented technique relaxes the requirements on the scanning speed of the THz sensor and
facilitates an efficient scene scanning solution.
KEYWORDS: Antennas, Receivers, Radar, Transmitters, Manufacturing, Gallium arsenide, Interference (communication), Waveguides, Signal to noise ratio, Near field
The development of a 210 GHz radar system intended to study security applications such as personnel scanning is reported.
The system is designed to operate with a transmit antenna floodlighting the target scene and a mechanically
scanned antenna-integrated receiver module. For increased performance and potential future volume production the receiver
front-end is based on highly integrated MMICs manufactured using the IAF 0.1 μm GaAs mHEMT process made
available through a Swedish-German MoU. A single-chip MMIC solution is being developed containing feed antenna,
LNA, mixer and an LO multiplier-chain. The transmitter part is based on a high-power HBV quintupler source-module.
Conference Committee Involvement (1)
Terahertz Emitters, Receivers, and Applications
1 August 2010 | San Diego, California, United States
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