First customer installation and site trials with the new

First customer installation and site trials with the new SCANTER
5000 Series of radars from Terma A/S
By Jens Chr. Pedersen, Director, Product Portfolio & Innovation, Radar Systems, Terma A/S
The first customer installation of the new generation of Solid State, Coherent Frequency
Diversity and Time Diversity Radar was performed, for trial, in cooperation between the
Port of London Authority and Terma A/S during May 2010.
The installation was made at the Becton radar station located near London City Airport
and overlooking part of the river Thames. A SCANTER 5102 was installed next to earlier
generation SCANTER radar and connected to the 18’HP-F-35 Antenna at the site.
Figure 1: Radar image, SCANTER 5102 at the Port of London, Becton Radar site
Two series of new SCANTER radars
The SCANTER 5000 series comprises a new generation of Fully Coherent, Frequency
Diversity and Time Diversity, Solid State Radars with Software Defined Functionality for
professional applications such as VTS, Coastal Surveillance and Airport Surface Movement Radars (SMR).
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Similar technology is employed in the
SCANTER 6000 series of radars for Shipborne applications.
In order to extend lifespan of the most critical
part of the new design, the Solid State Power
Amplifier (SSPA), several new developments
have been realized. This includes low voltage,
low temperature, microwave power generation
with efficient temperature management, and
graceful degradation capability.
Extremely high resolution with small range cell
size and high pulse compression factors has
been achieved utilising 32-bit floating point
calculations throughout the signal processing
chain, providing lossless processing virtually
unrestricted by dynamics. Target definition is
in excess of that seen before and which results
in high definition radar images
Frequency Diversity and Time Diversity are
standard features for the new series of radars.
Application specific features include dedicated
set-up and processing, support for helicopter
guidance, and embedded automatic target
tracker.
Figure 2: SCANTER 5102 Transceiver
Communication as well as signal and track
distributions are preferably provided on single
or redundant IP network. Additional serial
communication lines are available for easy
integration into new or existing systems of
systems. The video outputs will be available in
both analogue, digital and IP network formats.
Operational test at the Port of London
With a total of 7 units built to normal production standard, the new radar series is subject
to intensive endurance and qualification testing at Terma facilities. 4 of the units are reserved for qualification activities including operational tests at customer locations in order to ensure the best possible status well ahead of the first production batch, now being
manufactured.
The digital radar concept with software defined functionality made the set-up very easy.
Installation and setting to work was done in one short day. Fine-tuning and profile set-up
at this first customer installation was done in just 4 hours!
All profiles utilized 6 frequencies in the maritime X-band. Manual as well as automatic
adjustment of sensitivity (CFAR) was included in the tests
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Figure 3: Location
Previously radars has been associated with kilowatts or even megawatts of transmitted
peak power, and the most amazing impression from the new technology is the ability to
obtain very high quality radar images with very low power levels. The fine resolution is
equally important as it obviously gives the operator very good discrimination between
targets and furthermore improves the results from the utilisation of Frequency Diversity
and Time Diversity.
In this case operation was performed with different profiles, all utilising 3 meter range
cell resolution and average transmitter power from 80 milliwats to 8 watts. One of the
profiles included a novel concept of power sector mode transmission. An average azimuth dependant power 8 watt was used downriver, 800 milliwats was used upriver and
80 milliwats was used in a 100 degrees sector across the shortest part of the river. No
transmission in a 150 degree sector towards northwest.
The Sector power transmission, in combination with the bandwidth occupied, even
for 6 frequencies, will assist operators/owners reduce the implications of
spectrum pricing and its perceived inefficient use, now starting to emerge in some
countries. The additional ability to select
sub bands for transmission will also increase robustness against interference
between radar stations and further enhance lifetime of the Solid state Power
Amplifiers.
The receiver will automatically adapt to
varying power levels, giving undisturbed
images to the radar operators.
Figure 4: Sector Power Transmission
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Figure 5: Sector power mode, sailing boat passing through zone with 80 mW average transmitted power
The new series of radars utilises pulse compression. Up to 100 micro second (15 km in
length) chirps are pulse compressed to few meter long pulses as illustrated in Figure 6.
Compared to other Solid state techniques, such as FMCW this has several advantages
in applications like this, one is that existing antenna technology is maintained as in this
case at The Port of London.
Equivalent
compressed
power
Power
Chirps
transmitted
Transmitter
Time
Antenna
Receiver /
Processing
Power
Echo
Time
Time
Figure 6: Pulse compression. Long weak received chirps are converted into short
powerful pulses after reception
The simultaneous utilisation of up to 6 sub-bands, each with very low power levels allow
for very fine details from very short to very long range. The SCANTER 5000 utilise 3 m
range cell resolution in the entire range from 0 to 98 kilometers. In other words the range
resolution is as fine as the below picture at all ranges!
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Figure 7: Close range image, SCANTER 5102, Radar Cross Section measurement
in progress. The steel poles downstream are separated 11 by 15 m and yet displayed as individual returns.
The new radar series has been designed to comply with IMO, ICAO and IALA V-128
requirements and recommendations.
For the most powerful version of the new radar series, performance exceeds the advanced examples in IALA V-128 by arbitrary 20%. This is of course subject to physical
constraints such as atmospheric propagation and the curvature of the earth.
In any case, the new radars are superior in respect to range resolution and performance
in adverse weather and the performance is outstanding in respect to small targets detection. To demonstrate this, a fender with a measured Radar cross section of 0.1 – 0.2
square meters was allowed to float on the river. The fender detected continuously to a
distance of more than 1.5 kilometers from the radar!
Finally, the interference rejection against disturbance from radars on ships passing near
by the radar was very effective and the dynamic range proved to be sufficient to eliminate any artifacts from the high number of large buildings in the area.
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Fender
PLA service vessel
Figure 8: PLA service vessel and fender floating downstream
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