Method for detecting and restoring cycle slip of GPS (Global Positioning System) carrier phase under dynamic environment

Abstract

The invention discloses a method for detecting and restoring the cycle slip of a GPS (Global Positioning System) carrier phase under dynamic environment, comprising the steps of: carrying out difference kalman filtering calculation by utilizing a double-difference code pseudo-range observed quantity so as to obtain two epoch GPS receiver coordinates; constructing a carrier phase cycle slip detection equation by utilizing the two epoch GPS receiver coordinates and two epoch double-difference carrier phase observed quantities, calculating the equation and computing a residual error RMS (Root Mean Square) value; comparing the residual error RMS value with a set threshold, if the residual error RMS is greater than the set threshold, determining that the cycle slip occurs, selecting a satellite combination with the minimum residual error as a combination without the cycle slip by taking five satellites as a combination so as to restore the cycle slip, and then ending; if the residual error RMS value is less than or equal to the set threshold, comparing the result deltaX of the calculated cycle slip detection equation with the set threshold, if the result deltaX is less than the set threshold, determining that no cycle slip occurs and exiting the cycle slip detection process; and if the result deltaX is greater than the set threshold, determining that the cycle slip can not be detected and quitting from the cycle slip detection process.

Description

technical field [0001] The present invention relates to the technical field of global satellite positioning and navigation, such as GPS, GLONASS, BD, GALILEO systems, especially in high-precision positioning systems using carrier phase, especially a method for detecting and repairing GPS carrier phase cycle slips in a dynamic environment method. Background technique [0002] In Global Navigation Satellite System (GPS) receivers, pseudorange measurements and carrier phase measurements with millimeter resolution are available. Carrier phase measurement is the most useful observation for GPS precise positioning. GPS positioning can be summarized into two categories, namely single point positioning and relative positioning. Single-point positioning uses observation data and ephemeris data collected at one point to determine the coordinates of a fixed point. The accuracy of single-point positioning is limited by ephemeris error, clock information, and pseudo-range measurement a...

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Problems solved by technology

[0004] Carrier phase measurement can only measure the fractional part of the phase that is less than a full cycle and the continuous full cycle count after locking the carrier phase

[0012] The polynomial fitting method, pseudorange and carrier phase combination method cannot completely repair cycle slips, especially small cycle slips, which cannot be detected and repaired; the ionospheric residual method requires dual-frequency observation data, and is not sensitive to some cycle slip combinations; kalman filter There is a problem of divergence in the method, especially in the case of large and frequent maneuvers of the moving carrier, the kalman filter method is easy to diverge, and cannot completely repair the cycle slip

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