ISO 8729:1987
(Main)Shipbuilding — Marine radar reflectors
Shipbuilding — Marine radar reflectors
Construction navale — Réflecteurs radars de marine
General Information
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Standards Content (Sample)
[SO
INTERNATIONAL STANDARD
3729
3rst edition
987-1 1-01
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
ORGANISATION INTERNATIONALE DE NORMALISATION
MEXAYHAPOAHAR OPrAHM3AuMR il0 CTAHAAPTM3AUMM
Shipbuilding - Marine radar reflectors
Construction navale - Réflecteurs radars de marine
Reference number
IS0 8729 : 1987 (E)
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Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
I
International Standard IS0 8729 was prepared by Technical Committee ISO/TC 8,
I Shipbuilding and marine structures.
Users should note that all International Standards undergo revision from time to time
and that any reference made herein to any other International Standard implies its
latest edition, unless otherwise stated.
I
O International Organization for Standardization, 1987 0
Printed in Switzerland
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IS0 8729 : 1987 (E)
INTERNATIONAL STANDARD
Shipbuilding - Marine radar reflectors
1 Scope and field of application 3.3 azimuthal polar diagram : Polar diagram relating the
echoing area of the reflector to the azimuthal angle about its
This International Standard specifies the minimum require-
vertical axis.
ments for a radar reflector intended to enhance returns from
small vessels as required by IMO Resolution A.384(X).
3.4 Luneberg reflector : Reflector, making use of a number
of concentric spheres of varying refractive index, capable of
It lays down the specification for the construction, perform-
focusing incident energy onto a reflecting surface. The energy
ance, installation, testing and inspection of such radar reflec-
is reradiated along the incident path. (See annex A.)
tors.
3.5 corner reflector : Reflector, consisting of three flat con-
ducting surfaces intersecting mutually at right angles, which
2 References reflects the greater part of the incident waves parallel to their
direction of incidence. (See annex B.)
IMO Resolution A.384(X1 (adopted on 14 November 19771,
Performance standards for radar reflectors.
4 Construction
IMO Resolution A.477(Xll) (adopted on 19 November 19811,
Performance standards for radar equipment.
4.1 Structure and materials
The materials used for the radar reflector shall be of sufficient
strength and quality as to make the reflector capable of main-
taining reflection performance under conditions of sea states,
3 Definitions
vibration, humidity and change of temperature likely to be ex-
perienced in the marine environment as specified in 6.2 and 6.3.
For the purposes of this International Standard, the following
Use of ferrous metals should be avoided.
definitions apply.
4.2 Colour
3.1 radar reflector : Any passive device which is designed
to enhance returns from small radar targets.
The radar reflector intended for installation on board vessels
shall not be coloured black. It should be of a highly visible
3.2 echoing area : 471 times the ratio of the power per unit
colour.
solid angle scattered in a specified direction to the power per
unit area in a plane wave incident on the scatterer from a
specified direction.
5 Performance requirements
The radar reflector shall comply with the following minimum
NOTE - It is dependent on the radar operating frequency, and the
requirements for all frequencies between 9 320 MHz and
three-dimensional orientation of the reflector. Polarization of the
9 500 MHz.
transmitter and the receiver affects the effective echoing area of the
reflector.
In case of free space propagation, the echoing area U can be measured
5.1 Reflecting pattern in horizontal plane
by the following equation :
5.1.1 The maximum echoing area of the radar reflector shall
P x c2 x a2 x U
S= be at least 10 m2.
(4xi3 x R4
where
5.1.2 Its azimuthal polar diagrams shall be such that its
S is the received power;
response over a total angle of 240° is not less than -6 dB with
P is the transmitting peak power;
respect to the maximum echoing area. The response shall not
G is the antenna gain; remain below this level over any single angle of more than IO".
A is the wave length;
NOTE - Typical azimuthal polar diagrams of two types of marine
R is the distance between radar and target. radar reflector are shown in annexes A and B.
1
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IS0 8729 : 1987 (E)
6.2.3 Vibration test
5.1.3 These requirements shall be assessed by reference to
related azimuthal polar diagrams about the reflector’s vertical
axis and tilted from the vertical at angles not exceeding f 3’. The radar reflector shall be mounted on a vibration table in a
manner which is recommended by the manufacturer for opera-
tional use. The reflector shall be vibrated at all frequencies
5.2 Reflecting pattern in vertical plane
between
The performance of the reflector, up to at least -t 15O from the
a) 5 Hz and 12,5 Hz with an excursion of f 1,6 mm;
horizontal shall be such that its response at any inclination re-
mains above - 12 dB with respect to its maximum echoing area
12,5 Hz and 25 Hz with an excursion of f 0,38 mm;
b)
over a total angle of at least 240O.
c) 25 Hz and 50 Hz with an excursion of f 0,l mm;
6 Type tests and inspection
taking at least 15 min to cover each frequency range. As an
alternative to b) and cl, the table shall be vibrated at all frequen-
Order of tests and inspections
6.1
cies between 12,5 Hz and 50 Hz at a constant maximum
acceleration of 10 m/s2 taking at least 30 min to cover the full
Mandatory tests and inspections shall normally be performed in
frequency range.
the following order :
This procedure shall be carried out in each of three mutually
- visual inspection of the structure and the materials (see
perpendicular directions of the radar reflector.
6.2.1);
If vibration responses are observed on the r
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