From its experience with the Searchwater long-range maritime radar
THORN EMI has developed the Skymaster multi-mode, software-driven
airborne early warning and maritime reconnaissance radar.  The
basic philosophy is that it was possible to design such a radar
using current technologies but at a cost only a fraction of the
larger AEW systems such as those found in the Boeing E-3. 
Skymaster is designed to have optimum performance in the AEW role,
with facilities for the automatic detection and tracking of fast
moving targets at high or low level, over land and sea, and for the
control of air interceptions.  A tactical plot can be maintained
with sufficient accuracy to permit control of engagements and over-
the-horizon targeting.

	The radar has a high-powered I-band (3 cm) travelling-wave
tube transmitter capable of operating in pulse Doppler mode for
look-down detection of low flying targets against ground clutter,
and also in a frequency-agile mode for the detection of maritime
surface targets and look-up detection of aircraft, while retaining
a surface radar picture.  A full stabilised antenna with 360
rotation provides continuous and sector-scan capabilities.  Track-
while-scan facilities enable specific targets to be tracked while
the radar continues to scan for other targets.

	Advanced signal processing techniques are optimised to enable
the system to detect airborne and surface targets in high levels
of clutter and high sea states at ranges of more than 100nm
(185km).

	A choice of operating methods includes a look-up mode
employing frequency-agility and within-beam integration techniques
to enhance the detection and tracking of high altitude targets; a
look-down mode using medium pulse repetition frequency pulse
Doppler techniques for the automatic tracking of low-altitude, fast
moving targets over land and sea; a frequency-agile maritime
surveillance mode for the detection of surface vessels, and coastal
navigation and adverse weather warning modes.  The radar can also
be used for over-the-horizon targeting, the maintenance of tactical
plots and the control of engagements.

	Radar information is presented to an operator on a bright,
flicker-free or colour television raster display; where appropriate
up to five operator displays can be installed.  The composite
display provides grid reference or latitude/longitude indication
of confirmed targets, with raw information presented in ground-
stabilised format or rolling map, with supplementary alphanumeric
annotation.  The system is controlled via a touch-sensitive plasma
panel, permitting the software to configure the system according
to the mode selected by the operator.  The operator can also
control the polarisation of the radar to reduce clutter and
optimise detection capability.

STATUS:  In development.  Flight trials with the radar installed
in the Pilatus Britten-Norman Defender began in late 1986.  While
this is the initial aircraft being promoted by both companies for
Third World AEW applications, it is known that THORN EMI has
proposed several other aircraft as platforms for the Skymaster
system, the Shorts Skyvan being a notable example.

CONTRACTOR: THORN EMI Electronics Ltd.
