06-02-2012, 03:04 PM
Ground-based radar interferometer for tracking fast approaching targets
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Introduction
Many radar systems have been developed in the last 50 years in
various applications including military and industrial
applications [1]. Generally, detection radars and tracking
radars have been installed independently in defence systems
since the two radar systems have different roles within the
military. Detection radars search wide fields of view to find
targets and tracking radars follow the position of the detected
target precisely. Also, the distance from the radar to a target is
often sufficiently large such that the tracking duration can be
considerably long. However, radar applications at closer
distances have been widely researched in recent years. These
radar systems are used for collision avoidance for
automotives, obstacle detection, forward imaging for
unmanned ground vehicles (UGV) and so on [2–4]. In
addition, in some army applications a radar is required to
detect and track threats at close distances.
Radar system design
2.1 Antenna
The transmitting and receiving antennas are separately
mounted on the proposed radar as shown in Fig. 1. Fig. 1a
shows the antenna structure of the radar interferometer and
Fig. 1b is the architecture of each antenna element. The
receiving antenna consists of five channels: one detection
channel and four tracking channels. R × 2 is a reference
channel and is used for detection
3 Experiment and analysis
To evaluate the proposed radar system, real field tests were
undertaken in Agency for Defense Development’s (ADD’s)
testing ground. Because the final goal of the radar system is
to obtain a precise 3D tracking accuracy of less than a few
tens of centimetres at a short distance, a method of
comparison for the 3D tracking positions (X, Y and Z) and
true position of a target in Cartesian coordinates is required.
Conclusion
A new radar system that can be used to detect and track a
target at short range has been proposed. In a short-range
defence system, to protect the army vehicle systems,
accurate detection and tracking of approaching threats is
required. Moreover, a fast reaction time is necessary
because of the very short distance and fast approaching
target. In order to design a radar applicable to this
application, a new waveform composed of CW and upward
FM waveform is proposed.