Parabola & Hyperbolic, Hyperbolic navigation system ParabolaSet of all points in a plane which are equal distance away from a given point and given line.Point – focusLine – directrix HyperbolaSet of points in a plane which having constant difference in distance from two fixed points.Fixed points – foci.Line joining two foci – base lineBase line … Read more
What is Pseudo range? True or not? Pseudo rangePseudo distance between satellite and GPS receiver.Pseudo range contain satellite clock and user clock offset error.To determine position GPS receiver calculate four range from four satellite at the time of transmission.GPS work on the principal of range measurement.Due to error, the measured range are not true, but … Read more
E LORAN Principle, ELoran limitation, E LORAN Operation area E LORANIndependent Dissimilar complement to GNSS.Low frequency terrestrial navigation system.ELoran uses pulse signal at a frequency of 100 khz. E LORAN principleELoran stations are grouped in chains – master station and 2 or more secondary station.First Master station transmit.Then successive transmission from secondary station.Transmission repeated periodically.ELoran … Read more
AIS Class A and Class B, Precautions for using as collision avoidance Precautions for using as collision avoidanceReceived information depends on the transmitted information.Position received might not be WGS 84 datum.AIS information can be wrong.Some ship doesn’t have AIS.Some ship might switched off AIS, so avoid over reliance.For these reasons, for collision avoidance follow colregs.But … Read more
Method of displaying AIS information & SOTDMA SOTDMA to share VHF frequencySOTDMA – self organized time division multiple access.All AIS station can synchronize their time slots from highly accurate time reference.This highly accurate time reference is called SOTDMA.Per minute there are 2,250 Slots available for the transmission of AIS data.Position, course, speed, and other data … Read more
