![\"\"](\"https:\/\/antoanhanghai.com\/wp-content\/uploads\/2024\/02\/IMO-e1708061579721.jpg\")
<\/p>\n<\/p>\n
TI\u00caU CHU\u1ea8N GPS<\/strong><\/p>\n GPS\/Glonass equipment<\/strong><\/p>\n \u00a0<\/strong><\/p>\n RECOMMENDATION ON PERFORMANCE STANDARDS FOR SHIPBORNE COMBINED GPS\/GLONASS RECEIVER EQUIPMENT<\/strong><\/p>\n \u00a0<\/strong><\/p>\n MSC.115(73)<\/strong><\/p>\n <\/p>\n \u00a0<\/strong><\/p>\n 1 INTRODUCTION<\/strong><\/p>\n 1.1 The Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) are space-based positioning, velocity and time systems. The GPS space segment will normally be composed of 24 satellites in six orbits. 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) < 6. The GLONASS space segment will normally be composed of 24 satellites placed in 3 orbital planes with 8 satellites in each plane. 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 PDOP < 6.<\/p>\n 1.2 A combined receiver, when compared to either the GPS or GLONASS receiver, offers improved availability, integrity, accuracy and resistance to interference; increased ease of installation, and the ability to operate in the differential GPS mode (DGPS), differential GLONASS mode (DGLONASS) and combined DGPS and DGLONASS mode, when available.<\/p>\n 1.3 Receiver equipment capable of combining individual satellite measurements from GPS and GLONASS constellations to form a single solution is intended for navigational purposes on ships with maximum speeds not exceeding 70 knots. Such equipment should, in addition to the general requirements contained in resolution A.694(17)* , comply with the following minimum performance requirements.<\/p>\n 1.4 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.<\/p>\n 2 COMBINED GPS\/GLONASS RECEIVER EQUIPMENT<\/strong><\/p>\n 2.1 The words “combined GPS\/GLONASS receiver equipment” as used in these performance standards include all the components and units necessary for the system to properly perform its intended functions. The equipment should include the following minimum facilities: .1 antenna capable of receiving both GPS and GLONASS signals; .2 combined GPS\/GLONASS receiver and processor; .3 means of accessing the computed latitude\/longitude position; .4 data control and interface; and .5 position display.<\/p>\n 2.2 The antenna design should be suitable for fitting at a position on the ship which ensures a clear view of the satellite constellations.<\/p>\n 3 PERFORMANCE STANDARDS FOR COMBINED GPS\/GLONASS RECEIVER EQUIPMENT <\/strong><\/p>\n 3.1 The combined GPS\/GLONASS receiver equipment should: .1.1 be capable of receiving and processing the Standard Positioning Service (SPS) signals of the GPS as modified by Selective Availability (SA) and range code signals in GLONASS and provide position information in latitude and longitude World Geodetic System (WGS) 84 co-ordinates in degrees, minutes and thousandths of minutes. Means may be provided to transform the computed position into data compatible with the datum of the navigational chart in use. Where this facility exists, the display and any data output should indicate that the co-ordinate conversation is being performed and should identify the co-ordinate system in which the position is expressed; .1.2 operate on the L1 frequency signal and C\/A code in GPS and L1 frequency signal and range code in GLONASS; .1.3 be provided with at least one output from which position information can be supplied to other equipment. The output of position information should be in accordance with the relevant international standards; * .1.4 have static accuracy such that the position of the antenna is determined to within 35 m (95%) in non-differential mode and 10 m (95%) in differential mode with horizontal dilution of precision (HDOP) < 4 or position dilution of precision (PDOP) < 6; .1.5 have dynamic accuracy such that the position of the ship is determined to within 35 m (95%) in non-differential mode and 10 m (95%) in differential mode with HDOP < 4 or PDOP < 6 under the conditions of sea states and ship’s motion likely to be experienced in ships**; .1.6 be capable of selecting automatically the appropriate satellite transmitted signals for determination of the ship’s position with the required accuracy and update rate; .1.7 be capable of acquiring satellite signals with input signals having carrier levels in the range of -130 dBm to -120 dBm. Once the satellite signals have been acquired the equipment should continue to operate satisfactorily with satellite signals having carrier levels down to -133 dBm; .1.8 be capable of acquiring position to the required accuracy, within 30 min, when there is no valid almanac data; .1.9 be capable of acquiring position to the required accuracy, within 5 min, when there is valid almanac data;<\/p>\n .1.10 be capable of re-acquiring position to the required accuracy, within 5 min, when all GPS and GLONASS signals are interrupted for a period of at least 24 h, but there is no loss of power; .1.11 be capable of re-acquiring position to the required accuracy, within 2 min, when subjected to a power interruption of 60 s; .1.12 be capable of re-acquiring an individual satellite signal and utilizing it in the position solution within 10 s after being blocked for 30 s; .1.13 generate and output to a display and digital interface* a new position solution at least once every 1 s; .1.14 have a minimum resolution of position, i.e. latitude and longitude of 0.001 minutes; .1.15 generate output to the digital interface* course over the ground (COG), speed over the ground (SOG) and universal time co-ordinated (UTC). Such outputs should have a validity mark aligned with that on the position output. The accuracy requirement for COG and SOG should not be inferior to the relevant Performance Standards for Heading* * and SDME;*** .1.16 have the facilities to process DGPS and DGLONASS data fed to it, in accordance with Recommendation ITU-R M.823 and the appropriate RTCM standard; and .1.17 be capable of operating satisfactorily in typical interference conditions<\/p>\n <\/p>\n