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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 Move-ment Radars (SMR).

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Similar technology is employed in the SCANTER 6000 series of radars for Ship-borne 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.

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 re-served for qualification activities including operational tests at customer locations in or-der 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

Figure 2: SCANTER 5102 Transceiver

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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 azi-muth 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 to-wards northwest.

The Sector power transmission, in combi-nation with the bandwidth occupied, even for 6 frequencies, will assist opera-tors/owners reduce the implications of spectrum pricing and its perceived ineffi-cient use, now starting to emerge in some countries. The additional ability to select sub bands for transmission will also in-crease robustness against interference between radar stations and further en-hance 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 aver-age 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

compressedpower

Antenna

Transmitter

Receiver /Processing

Power

Time

Chirpstransmitted

Power

TimeTime

Echo

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 dis-

played 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 ad-vanced 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 detec-tion. 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 elimi-nate any artifacts from the high number of large buildings in the area.

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Figure 8: PLA service vessel and fender floating downstream

Fender

PLA service vessel