1.3 These standards cover the basic requirements of position-fixing for navigation purposes only and do not cover other computational facilities which may be in the equipment.
2 GPS RECEIVER EQUIPMENT
2.1 The words "GPS receiver equipment" as used in these Performance Standards include all the components and units necessary for the system properly to perform its intended functions. The equipment should include the following minimum facilities:
.1 antenna capable of receiving GPS signals;
.2 GPS receiver and processor;
.3 means of accessing the computed latitude/longitude position;
.4 data control and interface; and
.5 position display and, if required, other forms of output.
2.2 The antenna design should be suitable for fitting at a position on the ship which ensures a clear view of the satellite constellation.
3 PERFORMANCE STANDARDS FOR GPS RECEIVER EQUIPMENT
3.1 The GPS receiver equipment should:
.1 be capable of receiving and processing the Standard Positioning Service (SPS) signals as modified by selective availability (SA) and provide position information in latitude and longitude World Geodetic System (WGS) 84 co-ordinates in degrees, minutes and thousandths of minutes and time of solution referenced to UTC. Means may be provided for transforming the computed position based upon WGS 84 into data compatible with the datum of the navigational chart in use. Where this facility exists, the display should indicate that co-ordinate conversion is being performed, and should identify the co-ordinate system in which the position is expressed;
.2 operate on the L1 signal and C/A code;
.3 be provided with at least one output from which position information can be supplied to other equipment. The output of position information based upon WGS 84 should be in accordance with IEC Publication 1162;
.4 have static accuracy such that the position of the antenna is determined to within 100 m (95%) with horizontal dilution of precision (HDOP) ≦ 4 (or PDOP ≦ 6);
.5 have dynamic accuracy such that the position of the ship is determined to within 100 m (95%) with HDOP ≦ 4 (or PDOP ≦ 6) under the conditions of sea states and ship's motion likely to be experienced in ships;
*Refer to resolution A.694(17), and IEC Publications 721-3-6, 945 and 1108-1.
