33 CFR 164.38 - Automatic radar plotting aids (ARPA).
Title 33: Navigation and Navigable WatersCHAPTER I: COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBCHAPTER P: PORTS AND WATERWAYS SAFETY PART 164: NAVIGATION SAFETY REGULATIONS 164.38 - Automatic radar plotting aids (ARPA). (a) The following definitions are used in this section? Bulk means material in any quantity that is shipped, stored, or handled without benefit of package, label, mark or count and carried in integral or fixed independent tanks. Constructed means a stage of construction where? (1) The keel is laid; (2) Construction identifiable with a specific ship begins; or (3) Assembly of that ship has commenced comprising at least 50 tons or 1 percent of the estimated mass of all structural material, whichever is less. Hazardous material means? (1) A flammable liquid as defined in 46 CFR 30.10-22 or a combustible liquid as defined in 46 CFR 30.10-15; (2) A material listed in table 151.05 of 46 CFR 151.05, table 1 of 46 CFR 153, or table 4 of 46 CFR Part 154; or (3) A liquid, liquefied gas, or compressed gas listed in 49 CFR 172.101. Self-propelled vessel includes those combinations of pushing vessel and vessel being pushed ahead which are rigidly connected in a composite unit and are required by Rule 24(b) of the International Regulations for Preventing Collisions at Sea, 1972 (72 COLREGS) (App. A to 33 CFR Part 81) to exhibit the lights prescribed in Rule 23 for a ?Power Driven Vessel Underway?. Tank vessel means a vessel that is constructed or adapted to carry; or carries, oil or hazardous materials in bulk as cargo or cargo residue. (b) An Automatic Radar Plotting Aid (ARPA) that complies with the standard for such devices adopted by the International Maritime Organization in its ?Operational Standards for Automatic Radar Plotting Aids? (Appendix A), and that has both audible and visual alarms, must be installed as follows: (1) Each self-propelled vessel, except a public vessel, of 10,000 gross tons or more carrying oil or hazardous materials in bulk as cargo or in residue on the navigable waters of the United States, or which transfers oil or hazardous materials in any port or place subject to the jurisdiction of the United States, must be equipped with an ARPA. (2) Each tank vessel of 10,000 gross tons or more operating on the navigable waters of the United States must be equipped with an ARPA. (3) Each self-propelled vessel of 15,000 gross tons or more that is not a tank vessel, and is not carrying oil or hazardous material in bulk as cargo or in residue operating on the navigable waters of the United States, and was constructed before September 1, 1984, must be equipped with an ARPA, except when it is operating on the Great Lakes and their connecting and tributary waters. (4) Each vessel of 10,000 gross tons or more, except when operating on the Great Lakes and their connecting and tributary waters, constructed on or after September 1, 1984 must be equipped with an ARPA. (c) [Reserved] (d)(1) Each device required under paragraph (b) of this section must have a permanently affixed label containing: (i) The name and address of the manufacturer; and (ii) The following statement: ?This device was designed and manufactured to comply with the International Maritime Organization (IMO) ?Performance Standards for Automatic Radar Plotting Aids (ARPA).? ? (2) [Reserved] Appendix A to ? 164.38?Performance Standards For Automatic Radar Plotting Aids (ARPA) 1Introduction 1.1The Automatic Radar Plotting Aids (ARPA) should, in order to improve the standard of collision avoidance at sea: .1Reduce the work-load of observers by enabling them to automatically obtain information so that they can perform as well with multiple targets as they can by manually plotting a single target; and .2Provide continuous, accurate and rapid situation evaluation. 1.2In addition to the General Requirements for Electronic Navigational Aids ([IMO] Res. A.281(VII)), the ARPA should comply with the following minimum performance standards. 2Definitions 2.1Definitions of terms in these performance standards are given in Annex 1. 3Performance Standards 3.1Detection 3.1.1Where a separate facility is provided for detection of targets, other than by the radar observer, it should have a performance not inferior to that which could be obtained by the use of the radar display. 3.2Acquisition 3.2.1Target acquisition may be manual or automatic. However, there should always be a facility to provide for manual acquisition and cancellation. ARPA with automatic acquisition should have a facility to suppress acquisition in certain areas. On any range scale where acquisition is suppressed over a certain area, the area of acquisition should be indicated on the display. 3.2.2Automatic or manual acquisition should have a performance not inferior to that which could be obtained by the user of the radar display. 3.3Tracking 3.3.1The ARPA should be able to automatically track, process, simultaneously display and continuously update the information on at least: .120 targets, if automatic acquisition is provided, whether automatically or manually acquired; or .210 targets, if only manual acquisition is provided. 3.3.2If automatic acquisition is provided, description of the criteria of selection of targets for tracking should be provided to the user. If the ARPA does not track all targets visible on the display, targets which are being tracked should be clearly indicated on the display. The reliability of tracking should not be less than that obtainable using manual recording of successive target positions obtained from the radar display. 3.3.3Provided the target is not subject to target swop, the ARPA should continue to track an acquired target which is clearly distinguishable on the display for 5 out of 10 consecutive scans. 3.3.4The possibility of tracking errors, including target swop, should be minimized by ARPA design. A qualitative description of the effects of error sources on the automatic tracking and corresponding errors should be provided to the user, including the effects of low signal to noise and low signal to clutter ratios caused by sea returns, rain, snow, low clouds and non-synchronous emission. 3.3.5The ARPA should be able to display on request at least four equally time-spaced past positions of any targets being tracked over a period of at least eight minutes. 3.4Display 3.4.1The Display may be a separate or integral part of the ship's radar. However, the ARPA display should include all the data required to be provided by a radar display in accordance with the performance standards for navigational radar equipment adopted by the Organization. 3.4.2 The design should be such that any malfunction of ARPA parts producing information additional to information to be produced by the radar as required by the performance standards for navigational equipment adopted by IMO should not affect the integrity of the basic radar presentation. 3.4.3 The display on which ARPA information is presented should have an effective diameter of at least 340 mm. 3.4.4The ARPA facilities should be available on at least the following range scales: .112 or 16 miles; .23 or 4 miles. 3.4.5There should be a positive indication of the range scale in use. 3.4.6The ARPA should be capable of operating with a relative motion display with ?north-up? and either ?head-up? or ?course-up? azimuth stabilization. In addition, the ARPA may also provide for a true motion display. If true motion is provided, the operator should be able to select for his display either true or relative motion. There should be a positive indication of the display mode and orientation in use. 3.4.7The course and speed information generated by the ARPA for acquired targets should be displayed in a vector or graphic form which clearly indicates the target's predicted motion. In this regard: .1ARPA presenting predicted information in vector form only should have the option of both true and relative vectors; .2An ARPA which is capable of presenting target course and speed information in graphic form, should also, on request, provide the target's true and/or relative vector; .3Vectors displayed should be either time adjustable or have a fixed time-scale; .4A positive indication of the time-scale of the vector in use should be given. 3.4.8The ARPA information should not obscure radar information in such a manner as to degrade the process of detecting targets. The display of ARPA data should be under the control of the radar observer. It should be possible to cancel the display of unwanted ARPA data. 3.4.9Means should be provided to adjust independently the brilliance of the ARPA data and radar data, including complete elimination of the ARPA data. 3.4.10The method of presentation should ensure that the ARPA data is clearly visible in general to more than one observer in the conditions of light normally experienced on the bridge of a ship by day and by night. Screening may be provided to shade the display from sunlight but not to the extent that it will impair the observer's ability to maintain a proper lookout. Facilities to adjust the brightness should be provided. 3.4.11Provisions should be made to obtain quickly the range and bearing of any object which appears on the ARPA display. 3.4.12When a target appears on the radar display and, in the case of automatic acquisition, enters within the acquisition area chosen by the observer or, in the case of manual acquisition, has been acquired by the observer, the ARPA should present in a period of not more than one minute an indication of the target's motion trend and display within three minutes the target's predicted motion in accordance with paragraphs 3.4.7, 3.6, 3.8.2 and 3.8.3. 3.4.13After changing range scales on which the ARPA facilities are available or resetting the display, full plotting information should be displayed within a period of time not exceeding four scans. 3.5Operational Warnings 3.5.1The ARPA should have the capability to warn the observer with a visual and/or audible signal of any distinguishable target which closes to a range or transits a zone chosen by the observer. The target causing the warning should be clearly indicated on the display. 3.5.2The ARPA should have the capability to warn the observer with a visual and/or audible signal of any tracked target which is predicted to close to within a minimum range and time chosen by the observer. The target causing the warning should be clearly indicated on the display. 3.5.3The ARPA should clearly indicate if a tracked target is lost, other than out of range, and the target's last tracked position should be clearly indicated on the display. 3.5.4It should be possible to activate or de-activate the operational warnings. 3.6Data Requirements 3.6.1At the request of the observer the following information should be immediately available from the ARPA in alphanumeric form in regard to any tracked target: 1. Present range to the target; 2. Present bearing of the target;. .3Predicted target range at the closest point of approach (CPA); .4Predicted time to CPA (TCPA); .5Calculated true course of target; .6Calculated true speed of target. 3.7Trial Manoeuvre 3.7.1The ARPA should be capable of simulating the effect on all tracked targets of an own ship manoeuvre without interrupting the updating of target information. The simulation should be initiated by the depression either of a spring-loaded switch, or of a function key, with a positive identification on the display. 3.8Accuracy 3.8.1The ARPA should provide accuracies not less than those given in paragraphs 3.8.2 and 3.8.3 for the four scenarios defined in Annex 2. With the sensor errors specified in Annex 3, the values given relate to the best possible manual plotting performance under environmental conditions of plus and minus ten degrees of roll. 3.8.2An ARPA should present within one minute of steady state tracking the relative motion trend of a target with the following accuracy values (95 percent probability values):
|Scenario/data||Relative course (degrees)||Relative speed (Knots)||CPA (n.m.)|
|Scenario/data||Relative course (degrees)||Relative speed (knots)||C.P.A. (n.m.)||TCPA (mins)||True course (degrees)||True speed (knots)|