GPS jamming, Spoofing, SBAS, GNSS GPS jammingGPS jammer intentionally transmitting same band radio wave to block user GPS receiver.GPS jammer can interfere within 200nm. SpoofingWhen GPS receiver give wrong position due to jamming then it is called spoofing. Spoofing threaten navigation. Solar flareSolar flare is simply large explosion from the sun. Due to this GPS … Read moreGPS jamming, Spoofing, SBAS, GNSS
Why three or more satellite needed? GPS error. Why three or more satellite needed?GPS works on Principle of range measurement.Range measured by GPS receiver is not true range but pseudo range. Pseudo range contain user clock error.If exact time is known then,Only one range will give spherical shell of position. But two range intersection will … Read moreWhy three or more satellite needed? GPS error.
Why 2 frequency are used in GPS? L1 carrier frequency 1575.42 mhzL2 carrier frequency 1227.60 mhzL1 consists of both P code, CA codeL2 consists of P codeL1 frequency is used by both civilian, militaryL2 frequency is only used by militaryFor this security reasons, two frequency are used in GPS
LORAN-C principle, Loran-c error & Difference between ELoran and Loran-c LORAN-C principleLoran-c works on a hyperbolic navigation system.Hyperbola overprinted on the navigation chart.So that a position line can be plotted on the chart.By measuring the time difference between arrivals of two pulse signals from two sources give a position line.The intersection point of these position … Read moreLORAN-C principle, Loran-c error & Difference between ELoran and Loran-c
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 moreParabola & Hyperbolic, Hyperbolic navigation system