The Maritime and Port Authority of Singapore (MPA) has set up a differential GPS (DGPS) broadcast service to enhance navigational safety in the Singapore Strait, its approaches and its port waters.
MPA’s DGPS is designed with a broadcast range of 200km and a positioning accuracy of ±5m to sub-metre accuracy, depending on users’ type of DGPS receivers. The DGPS signal can also be received inland, offering the same benefits on land and in the air.
The DGPS service is provided free via a marine radio beacon operating in the Medium Frequency (MF) band at 298kHz at a transmission speed of 100bps. The message format of the broadcast is based on international standards adopted from the Radio Technical Commission for Maritime Services, Special Committee 104 (RTCM SC-104 Version 2.0).
The types of broadcast message include Type 9-3, Type 16, Type 3, Type 5 and Type 7. The system provides reliable, all-weather and round-the-clock DGPS data with 99% availability.
The DGPS Reference Station consists of a 12-channel dual frequency (L1 & L2) GPS receiver, an MF radio beacon transmitter, an integrity monitoring station, remote control facilities and back-up facilities. The Reference Station is at a known fixed position and equipped with sophisticated GPS receivers. It compares the positions from its DGPS receiver with that of the known position and then generates DGPS data. An integrity monitoring station verifies the accuracy of the DGPS data and ensures that the system provides timely warnings to users if and when the system data should not be used. The technical details of the system is summarised in the table below.
Technical details
Please direct any further enquiries that you may have to The Chief Hydrographer of the Hydrographic Department
