Detection and Repair of Cycle Slips by Doppler Integral Method Combined with Ionospheric Residual Method

Abstract

The invention discloses a Doppler integration method combined with an ionospheric residual method to detect and repair a cycle slip, which comprises the following steps: a. Obtaining carrier phase and Doppler observation values ​​of two frequency points in a navigation system respectively by a receiver ; b, use the Doppler integral method to calculate the detection amount and carry out preliminary cycle slip detection to judge whether a cycle slip occurs; c, if a cycle slip occurs, the original cycle slip detection amount is corrected to within ±4 cycles; d, use the ionosphere The cycle slip is detected by the residual method, and the cycle slip detection value is obtained by the linear combination of the carrier phase, and the detection value is compared with the threshold value; if the absolute value of the ionospheric residual method detection value is greater than the threshold value, judge When a cycle slip occurs, go to step e; if the absolute value of the detected amount is less than the threshold value, it is judged that no cycle slip occurs; e, repair the cycle slip value. The method of the invention can effectively utilize the advantages of the strong cycle slip detection capability of the ionospheric residual method, and can also avoid defects that cannot be detected by the combination of cycle slips with special ratios.

Description

technical field [0001] The invention relates to the technical field of satellite navigation and positioning, in particular to a Doppler integration method combined with an ionospheric residual method to detect and repair cycle slips. Background technique [0002] With the development of precise positioning level, the precision required for positioning products is getting higher and higher. During the continuous carrier phase measurement process of the receiver, the loss of lock will lead to an error in the entire cycle count, which will cause a jump in the phase observation value compared with the previous one, which is called a cycle slip. The observation value used for precise positioning is the carrier phase, so to obtain the carrier phase value accurately, cycle slip detection and repair is a key step. The trajectory of the satellite in space is a smooth curve, so the change of the observed distance from the satellite to the receiver is also smooth and regular. The cyc...

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Problems solved by technology

[0003] (1) For the processing of dual-frequency cycle slips, the MW (Melborne-Wnbbena, MW) combination method of dual-frequency phase and pseudorange is often used. This combination eliminates the influence caused by the station-to-satellite geometric distance and the troposphere, and is suitable for dynamic situations Therefore, at a high sampling rate, it can effectively detect a cycle slip as small as one cycle. However, although the MW combination method can detect a cycle slip, it cannot tell which carrier the cycle slip occurs on, and When the carrier phases of the two frequency band signals have cycle slips of the same size, it will not be able to detect such a cycle slip combination, that is, the MW method cannot detect the same size cycle slips at two frequency points

[0004] (2) Geometric distance combination (GF) cannot detect when the cycle slip ratio on two frequency points is close to the reciprocal of the frequency ratio

[0005] (3) (TurboEdit) method is a method of combining MW combination and GF combination to make up for the shortcomings of their respective methods, but when the pseudo-range noise is large, the cycle slip of one cycle cannot be detected

However, the current Doppler integration detection cycle slip, because of the limitation of Doppler observation accuracy and data sampling rate, its detection accuracy is not high

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