FINAL REPORT - Stakeholders - Ofcom

3 Aeronautical Radio Determination
3.1 Introduction
In the aeronautical area, members of the study team have had meetings with UK CAA
(DAP) and NATS. Informal responses have been received from the radar suppliers
Thales and Raytheon.
3.2 Ground Based Primary Radar
Ground based primary radar is a long established tool for air traffic control services which
has the basic virtue of providing non – co-operative surveillance of aircraft. The joint civil
military nature of air traffic services in the UK is such that primary radar services are
available to both parties for a range of operational requirements. Primary radar is
expensive to provide and utilises substantial amounts of spectrum; however it continues
to provide an essential service.
3.2.1 Primary Radar Frequency Allocations
3.2.1.1 Scope
This section illustrates the current frequency usage profile in the UHF, L, S, X and Ku
frequency bands for civil radar installations in the United Kingdom.
3.2.1.2 UHF Band - 590-598 MHz
The frequency band 590-598 MHz (TV channel 36) is allocated to DAP /MoD for
aeronautical radio navigation. Two frequencies have been assigned by DAP for radars
operating in this band. (Radars in this band occupy a necessary bandwidth (-20dB) of 1.8
MHz).
3.2.1.3 L-Band - 1215 MHz to 1365MHz
The frequencies 1215 MHz to 1350MHz are used by DAP (Directorate of Airspace Policy)
for primary radar subject to co-ordination with the MoD (in practice civil primary radar is
limited to above 1243 MHz). The frequencies 1350 to 1365MHz may also be used by
DAP subject to co-ordination with DTI. There are 34 ATC L-band assigned civil radar
frequencies, 4 of which are reused (12%). Note that most radars require more than one
frequency assignment, for example, due to multipulse working or frequency diversity
operation. The band is also heavily used by the military (for radiolocation and GPS-L2),
earth exploration satellites (space-to-earth) and the amateur radio service on a secondary
basis. Civil radar frequencies and illustrative (20dB) bandwidths are listed in increasing
order in Table 3-1 below. The highlighted entries indicate the reused frequencies.
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