Resolution MSC.192(79)

 

ADOPTION OF THE REVISED PERFORMANCE STANDARDS FOR RADAR EQUIPMENT

(adopted on 6 December 2004)

 

THE MARITIME SAFETY COMMITTEE,

 

RECALLING Article 28(b) of the Convention on the International Maritime Organization concerning the functions of the Committee,

 

RECALLING ALSO resolution A.886(21) by which the Assembly resolved that the functions of adopting performance standards and technical specifications, as well as amendments thereto, shall be performed by the Maritime Safety Committee on behalf of the Organization,

 

NOTING resolutions A.222(VII), A.278(VIII), A.477(XII), MSC.64(67), annex 4, A.820(19) and A.823(19) containing performance standards applicable to marine radars being produced and installed at different time periods in the past,

 

NOTING ALSO that marine radars are used in connection/integration with other navigational equipment required to carry on board ships such as, an automatic target tracking aid, ARPA, AIS, ECDIS and others,

 

RECOGNIZING the need for unification of maritime radar standards in general, and, in particular, for display and presentation of navigation-related information,

 

HAVING CONSIDERED the recommendation on the revised performance standards for radar equipment made by the Sub-Committee on Safety of Navigation at its fiftieth session,

 

1. ADOPTS the Revised Recommendation on Performance Standards for radar equipment set out in the Annex to the present resolution;

 

2. RECOMMENDS Governments to ensure that radar equipment installed on or after 1 July 2008 conform to performance standards not inferior to those set out in the Annex to the present resolution.

 

Annex.

REVISED RECOMMENDATION ON PERFORMANCE STANDARDS FOR RADAR EQUIPMENT INDEX

 

1. SCOPE OF EQUIPMENT

 

The radar equipment should assist in safe navigation and in avoiding collision by providing an indication, in relation to own ship, of the position of other surface craft, obstructions and hazards, navigation objects and shorelines.

 

For this purpose, radar should provide the integration and display of radar video, target tracking information, positional data derived from own ship's position (EPFS) and geo referenced data. The integration and display of AIS information should be provided to complement radar. The capability of displaying selected parts of Electronic Navigation Charts and other vector chart information may be provided to aid navigation and for position monitoring.

 

The radar, combined with other sensor or reported information (e.g. AIS), should improve the safety of navigation by assisting in the efficient navigation of ships and protection of the environment by satisfying the following functional requirements:

 

- in coastal navigation and harbour approaches, by giving a clear indication of land and other fixed hazards;

 

- as a means to provide an enhanced traffic image and improved situation awareness;

 

- in a ship-to-ship mode for aiding collision avoidance of both detected and reported hazards;

 

- in the detection of small floating and fixed hazards, for collision avoidance and the safety of own ship; and

 

- in the detection of floating and fixed aids to navigation (see Table 2, note 3).

 

2. APPLICATION OF THESE STANDARDS

 

These Performance Standards should apply to all shipborne radar installations, used in any configuration, mandated by the 1974 SOLAS Convention, as amended, independent of the:

 

- type of ship;

 

- frequency band in use; and

 

- type of display,

 

providing that no special requirements are specified in Table 1 and that additional requirements for specific classes of ships (in accordance with SOLAS chapters V and X) are met.

 

The radar installation, in addition to meeting the general requirements as set out in resolution A.694(17)^*, should comply with the following performance standards.

______________

*IEC Publication 60945.

 

Close interaction between different navigational equipment and systems, makes it essential to consider these standards in association with other relevant IMO standards.

 

Table 1.

Differences in the performance requirements for various sizes/categories of ship/craft to which SOLAS applies

 

 

3. REFERENCES

 

References are in appendix 1.

 

4. DEFINITIONS

 

Definitions are in appendix 2.

 

5. OPERATIONAL REQUIREMENTS FOR THE RADAR SYSTEM

 

The design and performance of the radar should be based on user requirements and up-to-date navigational technology. It should provide effective target detection within the safety-relevant environment surrounding own ship and should permit fast and easy situation evaluation.^*

______________

* Refer to MSC/Circ.878 - MEPC/Circ.346 on Interim Guidelines for the application of Human Element Analysing Process (HEAP) to the IMO rule-making process.

 

5.1 Frequency

 

5.1.1 Frequency spectrum

 

The radar should transmit within the confines of the ITU allocated bands for maritime radar and meet the requirements of the radio regulations and applicable ITU-R recommendations.

 

5.1.2 Radar Sensor Requirements

 

Radar systems of both X and S-Bands are covered in these performance standards:

 

- X-Band (9.2-9.5 GHz) for high discrimination, good sensitivity and tracking performance; and

 

- S-Band (2.9-3.1 GHz) to ensure that target detection and tracking capabilities are maintained in varying and adverse conditions of fog, rain and sea clutter.

 

The frequency band in use should be indicated.

 

5.1.3 Interference susceptibility

 

The radar should be capable of operating satisfactorily in typical interference conditions.

 

5.2 Radar Range and Bearing Accuracy

 

The radar system range and bearing accuracy requirements should be:

 

Range - within 30 m or 1% of the range scale in use, whichever is greater;

 

Bearing - within 1°.

 

5.3 Detection Performance and Anti-clutter Functions

 

All available means for the detection of targets should be used.

 

5.3.1 Detection

 

5.3.1.1 Detection in Clear Conditions

 

In the absence of clutter, for long range target and shoreline detection, the requirement for the radar system is based on normal propagation conditions, in the absence of sea clutter, precipitation and evaporation duct, with an antenna height of 15 m above sea level.

 

Based on:

 

- an indication of the target in at least 8 out of 10 scans or equivalent; and

 

- a probability of a radar detection false alarm of 10^-4,

 

the requirement contained in Table 2 should be met as specified for X-Band and S-Band equipment.

 

The detection performance should be achieved using the smallest antenna that is supplied with the radar system.

 

Recognizing the high relative speeds possible between own ship and target, the equipment should be specified and approved as being suitable for classes of ship having normal (<30 kn) or high (>30 kn) own ship speeds (100 kn and 140 kn relative speeds respectively).

 

Table 2.
Minimum detection ranges in clutter-free conditions

 

 

_________________

¹ IMO revised performance standards for radar reflectors (resolution MSC.164(78)) Radar Cross Section (RCS) 7.5 m² for X-Band, 0.5 m² for S-Band.

 

² The corner reflector (used for measurement), is taken as 10 m² for X-Band and 1.0 m² for S-Band.

 

³ The typical navigation buoy is taken as 5.0 m² for X-Band and 0.5 m² for S-Band; for typical channel markers, with an RCS of 1.0 m² (X-band) and 0.1 m² (S-band) and height of 1 metre, a detection range of 2.0 and 1.0 NM respectively.

 

⁴ RCS for 10 m small vessel taken as 2.5 m² for X-Band and 1.4 m² for S-Band (taken as a complex target).

 

⁵ Reflectors are taken as point targets, vessels as complex targets and shorelines as distributed targets (typical values for a rocky shoreline, but are dependent on profile).

 

⁶ Detection ranges experienced in practice will be affected by various factors, including atmospheric conditions (e.g. evaporation duct), target speed and aspect, target material and target structure. These and other factors may either enhance or degrade the detection ranges stated. At ranges between the first detection and own ship, the radar return may be reduced or enhanced by signal multi-path, which depend on factors such as antenna/target centroid height, target structure, sea state and radar frequency band.

 

5.3.1.2 Detection at Close Range

 

The short-range detection of the targets under the conditions specified in Table 2 should be compatible with the requirement in paragraph 5.4.

 

5.3.1.3 Detection in Clutter Conditions

 

Performance limitations caused by typical precipitation and sea clutter conditions will result in a reduction of target detection capabilities relative to those defined in 5.3.1.1 and Table 2.

 

5.3.1.3.1 The radar equipment should be designed to provide the optimum and most consistent detection performance, restricted only by the physical limits of propagation.

 

5.3.1.3.2 The radar system should provide the means to enhance the visibility of targets in adverse clutter conditions at close range.

 

5.3.1.3.3 Degradation of detection performance (related to the figures in Table 2) at various ranges and target speeds under the following conditions, should be clearly stated in the user manual:

 

- light rain (4 mm per hour) and heavy rain (16 mm per hour);

 

- sea state 2 and sea state 5; and

 

- and a combination of these.

 

5.3.1.3.4 The determination of performance in clutter and specifically, range of first detection, as defined in the clutter environment in 5.3.1.3.3, should be tested and assessed against a benchmark target, as specified in the Test Standard.

 

5.3.1.3.5 Degradation in performance due to a long transmission line, antenna height or any other factors should be clearly stated in the user manual.

 

5.3.2 Gain and Anti-Clutter Functions

 

5.3.2.1 Means should be provided, as far as is possible, for the adequate reduction of unwanted echoes, including sea clutter, rain and other forms of precipitation, clouds, sandstorms and interference from other radars.

 

5.3.2.2 A gain control function should be provided to set the system gain or signal threshold level.

 

5.3.2.3 Effective manual and automatic anti-clutter functions should be provided.

 

5.3.2.4 A combination of automatic and manual anti-clutter functions is permitted.

 

5.3.2.5 There should be a clear and permanent indication of the status and level for gain and all anti-clutter control functions.

 

5.3.3 Signal Processing

 

5.3.3.1 Means should be available to enhance target presentation on the display.

 

5.3.3.2 The effective picture update period should be adequate, with minimum latency to ensure that the target detection requirements are met.

 

5.3.3.3 The picture should be updated in a smooth and continuous manner.

 

5.3.3.4 The equipment manual should explain the basic concept, features and limitations of any signal processing.

 

5.3.4 Operation with SARTs and Radar Beacons

 

5.3.4.1 The X-Band radar system should be capable of detecting radar beacons in the relevant frequency band.

 

5.3.4.2 The X-Band radar system should be capable of detecting SARTs and radar target enhancers.

 

5.3.4.3 It should be possible to switch off those signal processing functions, including polarization modes, which might prevent an X-Band radar beacon or SARTs from being detected and displayed. The status should be indicated.

 

5.4 Minimum Range

 

5.4.1 With own ship at zero speed, an antenna height of 15 m above the sea level and in calm conditions, the navigational buoy in Table 2 should be detected at a minimum horizontal range of 40 m from the antenna position and up to a range of 1 NM, without changing the setting of control functions other than the range scale selector.

 

5.4.2 Compensation for any range error should be automatically applied for each selected antenna, where multiple antennas are installed.

 

5.5 Discrimination

 

Range and bearing discrimination should be measured in calm conditions, on a range scale of 1.5 NM or less and at between 50% and 100% of the range scale selected:

 

5.5.1 Range

 

The radar system should be capable of displaying two point targets on the same bearing, separated by 40 m in range, as two distinct objects.

 

5.5.2 Bearing

 

The radar system should be capable of displaying two point targets at the same range, separated by 2.5° in bearing, as two distinct objects.

 

5.6 Roll and Pitch

 

The target detection performance of the equipment should not be substantially impaired when own ship is rolling or pitching up to ±10°.

 

5.7 Radar Performance Optimization and Tuning

 

5.7.1 Means should be available to ensure that the radar system is operating at the best performance. Where applicable to the radar technology, manual tuning should be provided and additionally, automatic tuning may be provided.

 

5.7.2 An indication should be provided, in the absence of targets, to ensure that the system is operating at the optimum performance.

 

5.7.3 Means should be available (automatically or by manual operation) and while the equipment is operational, to determine a significant drop in system performance relative to a calibrated standard established at the time of installation.

 

5.8 Radar Availability

 

The radar equipment should be fully operational (RUN status) within 4 minutes after switch ON from cold. A STANDBY condition should be provided, in which there is no operational radar transmission. The radar should be fully operational within 5 sec from the standby condition.

 

5.9 Radar Measurements Consistent Common Reference Point (CCRP)

 

5.9.1 Measurements from own ship (e.g. range rings, target range and bearing, cursor, tracking data) should be made with respect to the consistent common reference point (e.g. conning position). Facilities should be provided to compensate for the offset between antenna position and the consistent common reference point on installation. Where multiple antennas are installed, there should be provision for applying different position offsets for each antenna in the radar system. The offsets should be applied automatically when any radar sensor is selected.

 

5.9.2 Own ship's scaled outline should be available on appropriate range scales. The consistent common reference point and the position of the selected radar antenna should be indicated on this graphic.

 

5.9.3 When the picture is centred, the position of the Consistent Common Reference Point should be at the centre of the bearing scale. The off-centre limits should apply to the position of the selected antenna.

 

5.9.4 Range measurements should be in nautical miles (NM). In addition, facilities for metric measurements may be provided on lower range scales. All indicated values for range measurement should be unambiguous.

 

5.9.5 Radar targets should be displayed on a linear range scale and without a range index delay.

 

5.10 Display Range Scales

 

5.10.1 Range scales of 0.25, 0.5, 0.75, 1.5, 3, 6, 12 and 24 NM should be provided. Additional range scales are permitted outside the mandatory set. Low metric range scales may be offered in addition to the mandatory set.

 

5.10.2 The range scale selected should be permanently indicated.

 

5.11 Fixed Range Rings

 

5.11.1 An appropriate number of equally spaced range rings should be provided for the range scale selected. When displayed, the range ring scale should be indicated.

 

5.11.2 The system accuracy of fixed range rings should be within 1% of the maximum range of the range scale in use or 30 m, whichever is the greater distance.

 

5.12 Variable Range Markers (VRM)

 

5.12.1 At least two variable range markers (VRMs) should be provided. Each active VRM should have a numerical readout and have a resolution compatible with the range scale in use.

 

5.12.2 The VRMs should enable the user to measure the range of an object within the operational display area with a maximum system error of 1% of the range scale in use or 30 m, whichever is the greater distance.

 

5.13 Bearing Scale

 

5.13.1 A bearing scale around the periphery of the operational display area should be provided. The bearing scale should indicate the bearing as seen from the consistent common reference point.

 

5.13.2 The bearing scale should be outside of the operational display area. It should be numbered at least every 30° division and have division marks of at least 5°. The 5° and 10° division marks