| 摘要 |
The system's satellites are liable to cause occasional errors in the positioning of boats. With each message, data as transmitted of small distance deviations of all the satellites and the important distance deviations of at least one satellite. In each cycle, the number of messages equals the number of satellites. Each message is lightly weighted to the group data and heavily weighted to the single satellite. The transmission band, 285.3 to 285.7 kHz allows propagation over the sea with low levels of attenuation and atmospheric noise. The bit rate is therefore low and each message is limited to 50 bits in 10 seconds using 2.5 Hz two-phase modulation. USE/ADVANTAGE - Radio navigation. Low bandwidth allows favourable waveband.
|
