3.1 Range performance
requirement under normal propagation conditions, when the radar antenna is
mounted at a height of 15 m above sea level, is that the equipment should in the
absence of clutter give a clear indication of:
At 20 nautical miles when the ground rises to 60m.
At 7 nautical miles when the ground rises to 6m..2 Surface
At 7 nautical miles a ship of 5,000 gross tonnage, whatever her aspect.
At 3 nautical miles a small vessel of 10 m in length.
At 2 nautical miles an object such as a navigational buoy having
an effective echoing area of approximately 10m2
3.2 Minimum range
The surface object
specified in 3.1.2 should be clearly displayed from a minimum horizontal range
of 50 m from the antenna position up to a range or 1 nautical mile, without
changing the setting of controls other than the range selector.
3.3.1 The equipment should
provide, without external magnification, a daylight display with a minimum
effective diameter with the bearing scale of not less than:
- 180 mm on ships of 150* gross tonnage and more but less than 1,000* gross
- 250 mm on ships of 1,000* gross tonnage and more but less
than 10,000* gross tonnage;
- 340 mm on ships of
10,000* gross tonnage and upwards.
3.3.2 The equipment should provide the following set of range
scale of display: 0.25, 0.5, 0.75, 1.5, 3, 6, 12 and 24 nautical miles.
3.3.4 The range scale displayed and the distance between range
ring should be clearly indicated at all times.
3.3.5 Within the effective display radar video area, the
display should only contain information which pertains the use of the radar
display for navigation collision avoidance and which gas to be displayed there
because of its association with a target (e.q. target identifiers, vectors) or
because of some other direct relationship with the radar display.
3.3.6 The origin of the range scale (radar video) should start
at own ship, be linear and should not be delayed.
3.3.7 Multi-colour displays are permitted but the following
requirements should be met:
- target echoes should be displayed by means of the same basic colours and
the echo strength should not be displayed indifferent colours; and
- additional information may be shown in different colours.
3.3.8 The radar picture and information should be readable
under all ambient light conditions. If a light shield is necessary to facilitate
operation of the display in high ambient light levels, then means should be
provided for its ready attachment and removal.
3.3.9 Selected parts of the System Electronic
Navigation Chart (SENC) information may be displayed in such a way that the
radar information is not masked, obscured or degraded. If SENC information is
made available for a radar display it should at least include coastlines, own
ship's safety contour, dangers to navigation and fixed and floating aids to
navigation. The mariner should be able to select those parts of the SENC, which
can be made available and the mariner requires to be displayed.
3.3.10 For the superimposition of selected parts of the
- Reference management
Reference management is required to
ensure that the information displayed is correlated and in the same reference
and co-ordinate system;
- Display Area
effective display area should contain the available radar and SENC
- Matching and adjustment
in case of any
deviations between the chart image and the radar image through detectable
causes, manual adjustment should be possible. Any manual adjustment should be
clearly indicated as long as it is activated. Resetting should be possible in
a simple manner;
- priority in the display
of radar information should have priority;
The equipment should be capable of appropriately stabilizing the radar
image, ARPA vectors and SENC information. The operating mode should be clearly
- Independence of Radar/ARPA and SENC
6.1 the SENC information should not have an adverse effect on the radar
6.2 Radar/ARPA information and SENC information
should be clearly recognizable as such; and
6.3 in the case
of a malfunction of one component, the function of the other component should
not be affected.
3.3.11 The frequency band in use should be indicated to the
3.4 Range measurement
3.4.1 Electronic fixed
range rings should be provided for range measurements as follows:
- on the range scale 0.25, 0.5, 0.75 nautical miles at least two and not
more than six range rings should be provided, on each of the other mandatory
range scales six range rings should be provided; and
off-centred facilities have been provided, additional range rings should be
provided at the same range intervals.
3.4.2 An electronic variable range marker in the form of a
ring should be provided with a numeric readout of range. This readout should not
display any other data. For ranges of less than 1 nautical mile, there should be
only one zero before the decimal point. Additional variable range markers may be
3.4.3. The fixed
range rings and the variable range markers should enable the range of an object
to be measured with an error not exceeding 1% of the maximum range of the scale
in use, or 30m, whichever is the greater.
3.4.4 The accuracy should be maintained when the display is
thickness of the fixed range rings should not be greater than the maximum
3.4.6 On all range scales, it
should be possible to set the variable maker with the required precision within
5 s in all cases. A range that is set by the user should not change
automatically when the range scale is changed.
3.5 Heading indication
The heading of the ship should be indicated by a continuous line on the display
with a maximum error of not greater than 1°. The thickness of the displayed heading line should not be greater
than 0.5° measured at maximum range at the edge of the radar display. The
heading line should extend from the trace origin to the edge of the display.
3.5.2 Provision should be
made to switch off the heading indicator by a device which cannot be left in the
"heading line off" position.
3.5.3 A heading marker should be displayed on the bearing
3.6 Bearing measurement
3.6.1 An Electronic Bearing Line, (EBL), should be provided
with a numeric readout of bearing to obtain with 5s the bearing of any object
whose echo appears on the display.
3.6.2 The EBL should enable the bearing go a target whose
echo appears at the edge of the display to the display to be measured with m
maximum error of not greater than ±1°.
3.6.3 The EBL
should be displayed on the screen in such a way that it is clearly
distinguishable from the heading indicator.
3.6.4 It should be possible to vary the brilliance of the
EBL. This variation may be separate or combined with the intensity of other
markers. IT should be possible to remove the EBL completely from the screen.
3.6.5 The rotation of the EBL
should be possible in both directions continuously or in steps of not more than
numeric readout of the bearing of the EBL should be displayed with at least 4
digits, including one after the decimal point. The EBL readout should not be
used to display any other data. There should be a positive identification of
whether the bearing indicated is a relative bearing or a true bearing.
3.6.7 A bearing scale around
the edge of the display should be provided. Linear or non-linear bearing scale
may be provided.
bearing scale should have division marks for at least each 5°, with the 5° and 10° divisions clearly distinguishable from each other. Numbers should
clearly identify at least each 30° division.
It should be possible to measure the bearing relative to the heading line and
should be possible to move the position of the EBL origin away from the own ship
to any desired point on the effective display area. By a fast simple operation
it should be possible to move the EBL origin back to own ship's position on the
screen. On the EBL, it should be possible to display a variable range
The equipment should be capable of displaying as
separate indications on a range scale of 1.5 nautical miles, two small similar
targets at range of between 50% and 100% of the range scale, and on the same
bearing, separated by not more than 40 m in range.
should be capable of displaying as separate indications two small similar
targets both situated at the same range between 50% and 100% of the 1.5 nautical
mile range scale, and separated by not more than 2.5° in bearing
3.8 Roll or pitch
The performance of the
equipment should be such that when the ship is rolling or pitching up to ±10°. The range performance requirements of 3.1 and 3.2 continue to be
3.9 Antenna Scan
The scan should be
clockwise, continuous and automatic through 360°of azimuth. The antenna rotation rate should be not less than 20
revolutions per minute. The equipment should start and operate satisfactorily in
relative wind speeds of up to 100knots. Alternative methods of scanning are
permitted provided that the performance is not inferior.
3.10 Azimuth stabilization
3.10.1 Means should be provided to enable the display to be
stabilized in azimuth by a gyro-compass, or its equivalent in performance. The
accuracy of alignment with the compass transmission should be within 0.5° with a compass rotation rate of 2 revolutions per minute.
3.10.2 The equipment should
operate satisfactorily in the head-up unstabilized mode when the azimuth
stabilization is inoperative.
3.10.3 Change over from one display mode to the other
should be possible within 5 s and achieve the required bearing accuracy.
3.11 Performance monitoring
Means should be
available, while the equipment is used operationally, to determine readily a
significant drop in system performance relative to a calibration standard
established at the time of installation. Means should be provided to check that
the equipment is correctly tuned in the absence of targets.
3.12 Anti-clutter devices
3.12.1 Suitable means should be provided for the
suppression of unwanted echoes from sea clutter, rain and other forms of
precipitation, clouds, sandstorms and from other radars. It should be possible
to adjust manually and continuously the anti-clutter controls. In addition,
automatic anti-clutter controls may be provided; however, they should be capable
of being switched off.
3.12.2 The operational requirement, when the radar antenna
is mounted at a height of 15 m above sea level. is that the equipment should,
even in the presence of sea clutter, give a clear indication of a standard
reflector up to 3.5 nautical miles.
After switching on from cold the equipment
should become fully operational within 4 min. A stand-by condition should be
provided from which the equipment cal be brought to an operational condition
within 15 s.
Operational controls should
be accessible and easy to identify and use. Controls should be identified and
easy to operate.
The equipment should be capable of being
switched on and off and operated from the master display position.
It should be possible to vary the brilliance of the fixed range
rings and the variable range markers and electronic bearing lines and to remove
them independently and completely from the display.
3.14 Operation with radar beacons and SARTS
3.14.1 Radar should be able to detect and display signals
from radar beacons and 9 GHz radar should also be able to detect and display
signals from Search and Rescue Transponder (SARTs)
3.14.2 All radars operating in the 9GHz band
should be capable of operation in a horizontally polarized mode.
3.14.3 It should be possible to switch
off those signal processing facilities which might prevent a radar beacon of
SART from being shown on the radar display.
3.15 Display modes
The equipment should be capable of operation in relative and true motion.
3.15.2 The radar origin
should be capable of being off-set to at least 50% and not more than 75% of the
radius of the display.
3.15.3 The radar should be capable of sea and ground
stabilisation. With sea of ground stabilisation the accuracy and discrimination
of the display should be at least equivalent to that required by this
Speed and Distance Measuring Equipment (SDME) Providing the ship's speed through
the water to the radar should be capable of providing the speed in the fore and
ground stabilized input should be two-dimensional. It may be provided from the
SDME, from an electronic position-fixing system or from radar tracked stationary
targets. The speed accuracy should be in accordance with the requirements of
The type of input and stabilisation in use should be displayed.
3.15.7 It should also be possible to
input the ship's speed manually from 0 (zero) knots to 30 knots in steps of not
more than 0.2 knots.
Provision should be made for manual input of set and drift.
3.16 Interference from external magnetic fields
After installation and adjustment on board, the
bearing accuracy as prescribed in this performance Standard should be maintain
without further adjustment irrespective of the movement of the ship in the
earth's magnetic field.
3.17 Radar installation
installation, including the antenna, should be in such a manner that the
performance of the radar system is not substantially impaired. Guidance on
installation should be given in manufacturer documentation.
3.18 Failure Warnings and Status
If there is
any detectable reason why the information presented to the operator is invalid,
adequate and clear warning should given to the operator.