Radionavigation equipment - 5.6
5.6
Resolution A.819(19)-Adopted on 23 November 1995
PERFORMANCE STANDARDS FOR SHIPBORNE GLOBAL POSITIONING SYSTEM (GPS) RECEIVER EQUIPMENT
THE ASSEMBLY,
RECALLING Article 15(j) of the Convention on the International Maritime Organization concerning the functions of the Assembly in relation to regulations and guidelines concerning maritime safety,
HAVINC ADOPTED by resolution A.815(19) the IMO policy for the recognition and acceptance of suitable radionavigation systems intended for international use to provide ships with navigational position-fixing throughout their vovages,
RECOGNIZING that the Maritime Safety Committee has identified that the Global Positioning System (GPS) may be a component of the world-wide radionavigation system,
NOTING that shipborne receiving equipment for the world-wide radionavigation system should be designed to satisfy the detailed requirements of the particular system concerned,
HAVINC CONSIDERED the recommendation made by the Maritime Safety Committee at its sixty-fourth session,
1. ADOPTS the Recommendation on Performance Standards for Shipborne Global Positioning System (GPS) Receiver Equipment set out in the annex to the present resolution;
2. INVITES Governments to ensure that GPS receiver equipment carried on ships of their flag conform to the performance standards set out in the annex to the present resolution;
3. REQUESTS the Maritime Safety Committee to keep these Performance Standards under review and to adopt amendments thereto, as necessary.
Annex
RECOMMENDATION ON PERFORMANCE STANDARDS
FOR SHIPBORNE GLOBAL POSITIONING SYSTEM (GPS)
RECEIVER EQUIPMENT
1 INTRODUCTION
1.1 The Global Positioning System (GPS) is a space-based positioning, velocity and time system that has three major segments: Space, Control and User. The GPS space segment will normally be composed of 24 satellites in six orbits. The satellites operate in circular 20,200 km orbits at an inclination angle of 55°with a 12 h period. The spacing of satellites in orbit will be arranged so that a minimum of four satellites will be in view to users world-wide, with a position dilution of precision (PDOP) of ≦6. Each satellite transmits on two "L" band frequencies, L1 (1575.42 MHz) and L2 (1227.6 MHz). L1 carries a precise (P) code and coarse/acquisition (C/A) code. L2 carries the P code. A navigation data message is superimposed on these codes. The same navigation data message is carried on both frequencies.
