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Detection of Marine Radar Targets

Published online by Cambridge University Press:  21 October 2009

Abstract

A radar must detect targets before it can display them. Yet manufacturers' data sheets rarely tell us what the products will detect at what range. Many of the bigger radars are Type Approved so we consult the relevant IMO performance standard A 477 (XII). Paraphrasing Section 3.1 of the draft forthcoming revision (NAV 41/6): under normal propagation conditions with the scanner at height of 15 m, in the absence of clutter, the radar is required to give clear indication of an object such as a navigational buoy having a radar cross section area (RCS) of 10 m2 at 2 n.m. and, as examples, coastlines whose ground rises to 60/6 m at ranges of 20/7 n.m., a ship of 5000 tons at any aspect at 7 n.m. and a small vessel 10 m long at 3 n.m.

This helps, but suppose we must pick up a 5 m2 buoy at g km? What happens in clutter? Should we prefer S- or X-band? To answer such questions we use equations which define the performance of surveillance radars, but the textbooks and specialist papers containing them often generalize with aeronautical and defence topics, making life difficult for the nonspecialist.

This paper attempts a concise and self-contained engineering account of all main factors affecting detection of passive and active targets on civil marine and vessel traffic service (VTS) radars. We develop a set of equations for X- and S-band (3 and 10 cm, centred on 9400 and 3000 MHz respectively), suited for spreadsheet calculation.

Sufficient theory is sketched in to indicate where results should be valid. Some simplifications of conventional treatments have been identified.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 1996

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References

REFERENCES

1Kingsley, S. P. and Quegan, S. (1992). Understanding Radar Systems. McGraw-Hill. ISBN 0–07–707426–2. (‘K&Q’ below.) Chapter 1.Google Scholar
2Trim, R. M. (1995). Radar transponders and radar target enhancers. This Journal, 48, 397.Google Scholar
3Skolnik, M.I. (ed.) (1970). Radar Handbook. McGraw-Hill. ISBN 07–057908–3 (‘RH’ below.) Chapter 4.Google Scholar
4 RH, chapter 2, equation 56.Google Scholar
5 RH, chapter 2, figure 20.Google Scholar
6 RH, figures 2.17.Google Scholar
7 RH, chapter 2, table 9.Google Scholar
8 RH, chapter 24, table 12.Google Scholar
9Briggs, J. N. (1996). ‘Radar Transponders and Radar Target Enhancers’, This Journal, 49, 280.Google Scholar
10 K&Q, chapter 9.Google Scholar
11Nathanson, F. E. (1969). Radar Design Principles. McGraw-Hill, New York, Tables 7.2–7.8.Google Scholar
12 World Meteorological Organization table, in IRS, table 13.1.Google Scholar
13Skolnik, M. I. (1983). Introduction to Radar Systems. International Student Edition, 2nd ed. McGraw-Hill. ISBN 0–07–066572–9. (‘IRS’ below.) Figure 13.4.Google Scholar
14 K&Q, chapter 4.Google Scholar
15 RH, chapter 5.Google Scholar
16 IRS, figure 2.22.Google Scholar