FINAL REPORT - Stakeholders - Ofcom

of this study). These frequencies are shared in the UK with the Radiolocation Service on
a co-primary basis.
Again, both in Region 1 and in the UK the frequencies 9200 – 9300 MHz are allocated to
Maritime Radionavigation on a primary basis and are shared with the Radiolocation
Service on a co-primary basis.
In addition, the frequencies 9300 – 9500 MHz are allocated to Maritime Radionavigation
on a primary basis in the UK, but this is not a Region 1 allocation per se as the Region 1
allocation in this frequency range is simply for Radionavigation on a primary basis and
radiolocation on a secondary basis. These frequencies are shared with Aeronautical
Radionavigation (in the UK) on a co-primary basis and Radiolocation on a secondary
basis. This band is the most commonly used for maritime radar with over 800,000 shipborne
radars believed to be in operation.
The UK frequency allocation table, footnote UK120, indicates that the use of the
frequency range 9200 – 9500 MHz for maritime radionavigation is for shipborne radar and
RACONs with harbour radars by special arrangement.
The MoD is allocated the range 9200 – 9300 MHz for the radiolocation service and the
range 9300 – 9500 MHz for the radionavigation service.
4.2 Ground Based
4.2.1 MSR (Maritime Surveillance Radar)
Ground based Maritime Surveillance Radar (MSR) is used to track the movement of
shipping in and around coastal (and to a lesser extent in-shore) waterways. Radars are
employed by a number of organisations such as the Maritime and Coastguard Agency
(MCA) who have 3 radars covering the English Channel, as well as operators of ports and
docks. In addition, some private companies operate radars (and other services) to provide
a set of services known as Vessel Traffic Services (VTS). VTS is particularly appropriate
in the approaches and access channels of a port and in areas having high traffic density,
movements of noxious or dangerous cargoes, navigational difficulties, narrow channels,
or environmental sensitivity.
4.2.1.1 Technology Description
The principles of operation of marine primary radars are fundamentally the same as the
aeronautical systems described elsewhere in this report and thus the technological
background has not been repeated for the sake of brevity. There are, however, a number
of significant differences in the way in which radar is employed in the maritime sector as
opposed to the aeronautical sector:
• Velocity of traffic: The velocity of maritime traffic is much lower placing less
stringent demands on update rate. Also this difference may provide some
increased tolerance to occasional loss of detection.
• Interference suppression: Maritime radars are required to suppress high levels
of emissions from adjacent radars. In the case of aeronautical radar, a few, wellspaced
ground-based radars are used to plot the movements of various aircraft.
Whilst facsimiles of this exist for ground based maritime radars insofar as there
are networks of ground-based maritime radars tracking vessels in and out of
ports for example, the majority usage of maritime radar is on the vessels
themselves to aid navigation and safety in busy waterways. Thus maritime radars
rely heavily on their interference suppression (pulse repetition frequency
discrimination) circuits to minimise the effects of interference caused by other
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