摘要:
A signal processing system for demodulating navigation bits from a satellite signal is disclosed herein. The signal processing system includes a digital baseband processor for determining a boundary between two navigation bits in the navigation bits according to a first plurality of coarse acquisition (C/A) codes captured from the satellite signals, storing the first plurality of C/A codes, and demodulating a second plurality of C/A codes captured after determining the boundary to recover a first series of the navigation bits. The signal processing system further includes a complementary demodulating unit coupled to the digital baseband processor for demodulating the first plurality of C/A codes to recover a second series of the navigation bits.
摘要:
A GPS receiver includes a demodulator for obtaining ephemeris data and almanac data from a navigation message sent by satellites, and includes a calculator. The calculator is used for calculating almanac correction parameters according to coordinate differences between ephemeris-based coordinates of the satellites and almanac-based coordinates of the satellites. The GPS receiver also includes a satellite position calculator for calculating the ephemeris-based coordinates of the satellites according to the ephemeris data, for calculating the almanac-based coordinates of the satellites according to the almanac data, and for calculating positions of the satellites according to the ephemeris data, the almanac data and the almanac correction parameters.
摘要:
A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.
摘要:
A GPS receiver includes a demodulator for obtaining ephemeris data and almanac data from a navigation message sent by satellites, and includes a calculator. The calculator is used for calculating almanac correction parameters according to coordinate differences between ephemeris-based coordinates of the satellites and almanac-based coordinates of the satellites. The GPS receiver also includes a satellite position calculator for calculating the ephemeris-based coordinates of the satellites according to the ephemeris data, for calculating the almanac-based coordinates of the satellites according to the almanac data, and for calculating positions of the satellites according to the ephemeris data, the almanac data and the almanac correction parameters.
摘要:
A method for correcting errors for an Inertial Navigation System. The method includes the steps of determining a working state of the Inertial Navigation System based on a current positioning parameter of the moving object, a navigation map-based reference positioning parameter and a GPS-based reference positioning parameter, and replacing an initial parameter of the Inertial Navigation System with the GPS-based reference positioning parameter and resetting the Inertial Navigation System to an initial state if the Inertial Navigation System is determined to be in an abnormal working state.
摘要:
A moving information determination apparatus includes an ECA (Earth Center Assistant) information acquisition module, an altitude information and position information storage module and a moving information calculation module. The altitude information and position information storage module provides initial position information of the moving information determination apparatus and altitude information of the moving information determination apparatus. The ECA acquisition module obtains a radius of the Earth at the current position of the moving information determination apparatus. The moving information calculation module calculates the current position and/or velocity of the moving information determination apparatus based on the radius of the Earth and a plurality of signals from a plurality of satellites.
摘要:
A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.
摘要:
A signal processing system for demodulating navigation bits from a satellite signal is disclosed herein. The signal processing system includes a digital baseband processor for determining a boundary between two navigation bits in the navigation bits according to a first plurality of coarse acquisition (C/A) codes captured from the satellite signals, storing the first plurality of C/A codes, and demodulating a second plurality of C/A codes captured after determining the boundary to recover a first series of the navigation bits. The signal processing system further includes a complementary demodulating unit coupled to the digital baseband processor for demodulating the first plurality of C/A codes to recover a second series of the navigation bits.