Improved dual-frequency real-time cycle slip detection and repair method, system, device and medium

Abstract

The application provides an improved dual-frequency real-time cycle slip detection and repair method, system, device and medium, and the steps of the method comprise: detecting whether cycle slips occur in two frequency points in phase observations of a satellite by using a wide lane combination and a geometry-independent combination; if yes, determining cycle slip numbers of the two frequency points respectively; presetting deviation amounts corresponding to the cycle slip numbers of the two frequency points; constructing a search condition by using at least a test quantity of the geometry-independent combination and the deviation amounts to search for the deviation amounts corresponding to the cycle slip numbers of the two frequency points; if the search is successful, updating the cycle slip numbers of the two frequency points by using the searched deviation amounts, and repairing the phase observation values of the two frequency points by using the updated cycle slip numbers respectively. The searched deviation amounts based on the search condition constructed by the application can update the cycle slip numbers to make them more accurate, the updated cycle slip numbers are used to repair the phase observation values of the two frequency points, the phase observation values of the satellite are more accurate, and this is beneficial to subsequent high-precision data processing and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite positioning, and more particularly, to an improved dual-frequency real-time cycle slip detection and repair method, system, device and medium. BACKGROUND

[0002] At present, users have higher and higher requirements for the accuracy and real-time performance of satellite navigation positioning, and Precise Point Positioning (PPP) and Real-Time Kinematic Position (RTK) gradually become research hotspots in satellite navigation positioning. In the PPP data preprocessing, cycle slip detection and repair is a key problem to achieve high-precision positioning and rapid convergence of parameters. At present, the TurboEdit (dual-frequency cycle slip repair and detection) method is a cycle slip detection method for satellite carrier phase. The TurboEdit method combines the MW combination (Melbourne Wübbena combination) and the GF combination (Geometry Free combination) for cycle slip detection, and is widely used in multiple open-source GNSS (Global Navigation Satellite System) high-precision processing software and manufacturers' high-precision receivers, but it still has defects.

[0003] The cycle slip number obtained by solving and simply rounding according to the TurboEdit method will be inaccurate due to the influence of pseudorange noise (about 0.3 m) and other errors. This situation is particularly prominent in many low-cost high-precision receivers. Through a large amount of data processing and analysis, it is found that the ΔN WL error caused by solving the wide lane ambiguity in real time single epoch can make the cycle slip number error reach 4.5 and 3.5 cycles, that is, the cycle slip number obtained by solving will swing up and down around the true value of the cycle slip number, and the swing amplitude is within 5 (4.5 rounded) cycles. At this time, if the cycle slip repair is still performed, the repaired carrier phase still has cycle slip. For this reason, many current software and receivers only perform cycle slip detection, but not repair, which reduces the number of available satellites and causes difficulties for high-precision data processing. SUMMARY

[0004] The present application aims to overcome at least one of the above-mentioned defects of the prior art, and provides an improved dual-frequency real-time cycle slip detection and repair method, system, device and medium to solve the problem that the cycle slip number obtained by solving according to the TurboEdit method is still not accurate enough.

[0005] The technical solution adopted by the present application comprises:

[0006] An improved dual-frequency real-time cycle slip detection and repair method, comprising: detecting whether cycle slips occur in phase observations of two frequencies of a satellite by using a wide-lane combination and a geometry-independent combination, and if so, determining the cycle slip numbers of the two frequencies respectively; presetting a deviation amount corresponding to the cycle slip numbers of the two frequencies, constructing a search condition for searching the deviation amount corresponding to the cycle slip numbers of the two frequencies by using at least the test quantity of the geometry-independent combination and the deviation amount corresponding to the cycle slip numbers of the two frequencies, searching the deviation amount corresponding to the cycle slip numbers of the two frequencies by using the search condition, and if so, updating the cycle slip numbers of the two frequencies by using the searched deviation amount, and repairing the phase observation values of the two frequencies by using the updated cycle slip numbers of the two frequencies respectively.

[0007] Since the TurboEdit method for detecting cycle slips by using a wide-lane combination and a geometry-independent combination has the problem of not being accurate enough in solving cycle slip numbers, the present application provides an improved dual-frequency real-time cycle slip detection and repair method for improving the existing TurboEdit method, after detecting that cycle slips occur and determining the cycle slip numbers of two frequencies, presetting a deviation amount of the cycle slip numbers of the two frequencies, presetting one deviation amount for each cycle slip number, and constructing a search condition by using at least the test quantity of the geometry-independent combination and the deviation amount corresponding to the cycle slip numbers of the two frequencies, for searching the deviation amount of the cycle slip numbers of the two frequencies. The search condition is based on the principle of detecting cycle slips by using a geometry-independent combination to search whether a deviation amount of cycle slip numbers can satisfy the condition of not detecting cycle slips. If a deviation amount satisfying the search condition is searched, the cycle slip numbers of the two frequencies are updated by using the searched deviation amount, the updated cycle slip numbers are more accurate and have smaller errors, and the updated cycle slip numbers are used to repair the phase observation values of the two frequencies, so that the phase observation values of the satellite are more accurate, which is beneficial to subsequent high-precision data processing and application.

[0008] Further, the search condition is used to search the deviation amount corresponding to the cycle slip numbers of the two frequencies, specifically: taking the cycle slip numbers of the two frequencies as the center, and searching the deviation amount corresponding to the cycle slip numbers of the two frequencies in a search range by using a search step.

[0009] Taking the determined cycle slip numbers as the search center, searching the deviation amount in a certain range by using a certain search step, after setting the search step and the range, the deviation amount satisfying the condition can be searched in a limited number of searches, so as to control the time length of the search process.

[0010] Further, at least by using the test quantity of the geometrically independent combination and the deviation quantity corresponding to the cycle slip number of the two frequency points, a search condition for searching the deviation quantity of the cycle slip number of the two frequency points is constructed, specifically: by using the cycle slip number of the two frequency points, the deviation quantity of the cycle slip number of the two frequency points, the test quantity of the geometrically independent combination and the wavelength of the frequency point, a search condition for searching the deviation quantity of the cycle slip number of the two frequency points is constructed.

[0011] The parameters in the search condition constructed by the application are composed of the cycle slip number of the two frequency points, the deviation quantity of the cycle slip number, the test quantity of the geometrically independent combination and the wavelength of the frequency point, wherein the test quantity of the geometrically independent combination refers to the parameter used for judging whether the cycle slip occurs in the geometrically independent combination. The judgment condition in the search condition is based on whether the principle of detecting the cycle slip in the geometrically independent combination can detect the cycle slip. When the cycle slip cannot be detected, since the parameters in the search condition contain the deviation quantity of the cycle slip number, it can be known that the determined cycle slip number needs to be combined with the deviation quantity of the cycle slip number to meet the condition that the cycle slip cannot be detected, and therefore the deviation quantity of the cycle slip number searched by the search condition can be used to update the cycle slip number, so that the cycle slip number is more accurate.

[0012] Further, the search condition constructed is: Wherein, the λ1 is the wavelength of the first frequency point, the λ2 is the wavelength of the second frequency point, the ΔN1 is the cycle slip number of the first frequency point, the ΔN2 is the cycle slip number of the second frequency point, the ΔL(i) is the test quantity of the geometrically independent combination, the j is the deviation quantity of the cycle slip number of the first frequency point, and the k is the deviation quantity of the cycle slip number of the second frequency point.

[0013] The deviation quantities j and k of the cycle slip numbers of the two frequency points are introduced in the search condition, the judgment condition is set to be less than 0.07 based on the principle of detecting the cycle slip in the geometrically independent combination, which represents that the cycle slip cannot be detected. When the deviation quantities j and k meeting the search condition are searched, it represents that the cycle slip numbers ΔN1 and ΔN2 of the two frequency points need to be combined with the deviation quantities j and k respectively to meet the condition that the cycle slip cannot be detected, and therefore the deviation quantities j and k searched can be used to update ΔN1 and ΔN2 respectively, so that they are more accurate, and the updated cycle slip numbers can better repair the phase observation values of the satellite.

[0014] Further, the search step is 1 cycle slip.

[0015] Further, the search range is between 0 cycle slip and 5 cycle slips.

[0016] The error range of the cycle slip number solved by the geometric independent combination and the wide lane combination is not more than 5 cycle slips, so it is feasible to search the deviation amount of the cycle slip number in the range between 0 cycle slip and 5 cycle slips. The search step is set to 1 cycle slip, the search range is set to between 0 cycle slip and 5 cycle slips, the search number is in a less state, and then the search process time and the search difficulty are moderate.

[0017] Further, the cycle slip numbers of the two frequency points are determined respectively, specifically, the floating point solution of the cycle slip numbers of the two frequency points is determined, and the floating point solution of the cycle slip numbers of the two frequency points is rounded as the cycle slip numbers of the two frequency points.

[0018] When the cycle slip numbers of the two frequency points are determined, the floating point solution of the cycle slip numbers is obtained first, the floating point solution is rounded, and then the deviation amount is searched, so that the calculation of the search process is simplified, and the search accuracy is improved.

[0019] An improved double-frequency real-time cycle slip detection and repair system, comprising: a cycle slip detection module, configured to detect whether cycle slips occur in two frequency points of satellite phase observations by using a wide lane combination and a geometric independent combination; a cycle slip determination module, configured to determine cycle slip numbers of the two frequency points respectively when the cycle slip detection module detects that cycle slips occur; and a search module, configured to preset a deviation amount corresponding to the cycle slip numbers of the two frequency points determined by the cycle slip determination module, construct a search condition for searching the deviation amount of the cycle slip numbers of the two frequency points by using at least a test quantity of the geometric independent combination and the deviation amount corresponding to the cycle slip numbers of the two frequency points, search the deviation amount of the cycle slip numbers of the two frequency points by using the search condition, and if the search is successful, update the cycle slip numbers of the two frequency points determined by the cycle slip determination module by using the searched deviation amount, and repair the phase observation values of the two frequency points respectively by using the updated cycle slip numbers of the two frequency points.

[0020] Further, the search module is configured to search the deviation amount corresponding to the cycle slip numbers of the two frequency points by using the search condition, specifically, the search module is configured to search the deviation amount corresponding to the cycle slip numbers of the two frequency points by using the search condition in a search range with the cycle slip numbers of the two frequency points determined by the cycle slip determination module as the center and with a search step.

[0021] Further, the search module is configured to construct the search condition for searching the deviation amount of the cycle slip numbers of the two frequency points by using at least the test quantity of the geometric independent combination and the deviation amount corresponding to the cycle slip numbers of the two frequency points, specifically, the search module is configured to construct the search condition for searching the deviation amount of the cycle slip numbers of the two frequency points by using the cycle slip numbers of the two frequency points determined by the cycle slip determination module, the deviation amount of the cycle slip numbers of the two frequency points, the test quantity of the geometric independent combination, and the wavelengths of the two frequency points.

[0022] Further, the search module constructs a search condition as follows: Wherein, the λ1 is the wavelength of the first frequency point, the λ2 is the wavelength of the second frequency point, the ΔN1 is the number of cycle slips of the first frequency point, the ΔN2 is the number of cycle slips of the second frequency point, the ΔL(i) is the test quantity of the geometrically independent combination, the j is the deviation quantity of the number of cycle slips of the first frequency point, and the k is the deviation quantity of the number of cycle slips of the second frequency point.

[0023] Further, the search step is 1 cycle slip, and the search range is between 0 cycle slips and 5 cycle slips.

[0024] Further, the cycle slip determination module is used for determining the number of cycle slips of the two frequency points respectively, specifically, the cycle slip determination module determines the floating point solution of the number of cycle slips of the two frequency points, and takes the integer of the floating point solution of the number of cycle slips of the two frequency points as the number of cycle slips of the two frequency points.

[0025] A computer device comprises a memory and a processor, the memory stores a computer program, and the processor realizes the improved double-frequency real-time cycle slip detection and repair method when executing the computer program.

[0026] A computer readable storage medium stores a computer program, and the computer program realizes the improved double-frequency real-time cycle slip detection and repair method when executed by a processor.

[0027] Compared with the prior art, the improved double-frequency real-time cycle slip detection and repair method has the following beneficial effects:

[0028] The improved double-frequency real-time cycle slip detection and repair method, system, device and medium provided by the application are improvements on the TurboEdit method for detecting cycle slips of satellite carrier phases. After detecting that cycle slips occur and determining the number of cycle slips of two frequency points, a search condition is constructed by using the test quantity of the geometrically independent combination and related parameters of the two frequency points, which is used for searching the deviation quantity of the number of cycle slips of the two frequency points. The deviation quantity searched is used to update the number of cycle slips of the two frequency points. The updated number of cycle slips is more accurate and has smaller error. The updated number of cycle slips is used to repair the phase observation values of the two frequency points, so that the phase observation values of the satellite are more accurate, which is beneficial to subsequent high-precision data processing and application. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the execution process of the method steps S1-S6 of the embodiment of the application.

[0030] Figure 2 It is a specific execution process schematic diagram of the method steps S1-S6 of the embodiment of the application.

[0031] Figure 3 The schematic diagram of the composition of each module of the system of the embodiment of the present application. DETAILED DESCRIPTION

[0032] The drawings of the present application are only for illustrative purposes and cannot be understood as a limitation of the present application. In order to better illustrate the following embodiments, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual size of the product; it can be understood by those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0033] As Figure 1 shown, the embodiment provides an improved dual-frequency real-time cycle slip detection and repair method, which is applied to the cycle slip detection and repair of a dual-frequency receiver when observing satellite phases, and the steps include S1-S6:

[0034] S1: detecting whether two frequency points in the phase observation of a satellite occur cycle slip by using a wide-lane combination and a geometry-independent combination, if yes, performing step S2; if no, ending the execution of the method;

[0035] Specifically, whether two frequency points in the phase observation of a satellite occur cycle slip is detected by using a wide-lane combination and a geometry-independent combination, which is close to the TurboEdit method in the prior art, and the specific process is as follows steps S11-S19:

[0036] In order to facilitate the description of the following process, the basic observation equations of GNSS carrier phase and code pseudorange are given here, see equations (1)-(4):

[0037]

[0038]

[0039]

[0040]

[0041] Wherein, L1 is frequency point 1 of the two frequency points, L1=λ1φ1, L2 is frequency point 2, L2=λ2φ2, λ1 is the wavelength of frequency point 1, λ2 is the wavelength of frequency point 2 of the two frequency points, f1 is the frequency of frequency point 1, f2 is the frequency of frequency point 2, φ1 is the carrier phase observation value of frequency point 1 in cycles, φ2 is the carrier phase observation value of frequency point 2 in cycles, ρ is the geometric distance between the dual-frequency receiver and the satellite, c is the speed of light, δt and δT represent the clock error of the dual-frequency receiver and the satellite clock error respectively, I is the ionospheric delay error, T is the tropospheric delay error, N1 is the carrier phase integer ambiguity of frequency point 1, and N2 is the carrier phase integer ambiguity of frequency point 2.

[0042] S11: Constructing a wide-lane combination pseudorange observation value PWL and carrier observations L WL , see equations (5), (6):

[0043]

[0044]

[0045] where P WL is the code pseudorange narrow-lane combination; λ WL is the phase translation of the carrier wide-lane combination into a distance (m); λ WL is the wavelength of the carrier wide-lane, approximately 86.2 cm; N WL = N1-N2 is the wide-lane ambiguity.

[0046] S12: Simultaneously solve equations (5) and (6) in step S11 to obtain the wide-lane ambiguity N WL , see equation (7):

[0047]

[0048] Equation (7) eliminates the effects of geometric distance, ionosphere and troposphere and system errors. A wide-lane ambiguity N WL can be calculated for each epoch according to equation (7). If the observations do not contain cycle slips, the wide-lane ambiguities N WL should be a set of values fluctuating around a certain fixed value.

[0049] S13: Use a sliding average model to calculate the average value and variance of the i-epoch wide-lane ambiguities using a sliding window of width m adjacent to the current epoch, see recursive equations (8) and (9):

[0050]

[0051]

[0052] where <N WL > i is the average value of the i-epoch wide-lane ambiguities; is the variance of the i-epoch wide-lane ambiguities; m represents the width of the sliding window participating in the average value calculation, m = min(N / 10, 25), N represents the number of epochs in the arc segment. The prerequisite of equation (8) is i ≥ m, if i < m, then the average value of the wide-lane ambiguities of the first i epochs <N WL > i and the root mean square.

[0053] S14: According to recursive equations (8) and (9) of step S13, compare the average values of the wide-lane ambiguities of the current epoch i and epoch i+1, and determine whether a cycle slip has occurred according to the equation set (10):

[0054]

[0055] |N WLi -<N WL > i-1 |≥4σ i and |N WLi+1 -N WLi |≤1, indicates that there is a cycle slip between epoch i and epoch i+1; |N WLi -<N WL > i-1 |≥4σ i and |N WLi+1 -N WLi |>1, indicates that there is a wild value between epoch i and epoch i+1, the wild value refers to a value that the gradient of the change of the sample value cannot reach in an actual sampling period; |N WLi -<N WL > i-1 |≤4σ i , indicates that there is no cycle slip between epoch i and epoch i+1.

[0056] S15: Construct a carrier phase ionosphere residual combination L of a geometry-independent combination GF and a geometry-independent combination pseudorange ionosphere combination P GF , see formula (11) and (12):

[0057] L GF = λ1φ1- λ2φ2 = I + λ1N1- λ2N2 = I + λ1N WL - λ I N2 (11)

[0058] P GF = P2- P1 = I (12)

[0059] wherein λ I is the narrow lane wavelength, about 5.4 cm, and I is the ionosphere delay.

[0060] S16: Subtract the carrier phase ionosphere residual combination L of adjacent epochs GF to obtain the difference ΔL(i) between the carrier phase ionosphere residual combinations of adjacent epochs, see formula (13):

[0061] ΔL(i) = L GF (i) - L GF (i-1) = ΔI' + λ1ΔN1- λ2ΔN2 (13)

[0062] wherein ΔI' = ΔI(i) - ΔI(i-1), and ΔI' represents the difference between the ionosphere delays of adjacent epochs i and i-1.

[0063] S17: judging whether a cycle slip occurs or not according to the difference AL(i) between the ionospheric residual errors of the adjacent epochs determined in step S16;

[0064] Specifically, if the 3 times root mean square of AL(i) is greater than 0.07, it is determined that a cycle slip occurs, and if the 3 times root mean square of AL(i) is less than or equal to 0.07, it is determined that no cycle slip occurs.

[0065] Since the ionosphere changes slowly, the value of AI' is about 0, and if no cycle slip occurs in the observation value, the values of AN1 and AN2 are both 0, and the value of AL(i) usually fluctuates randomly around 0. When a cycle slip occurs, the value of AL(i) at the position of the cycle slip will change significantly.

[0066] S18: if it is determined in step S14 or step S17 that a cycle slip occurs, performing step S2; if it is determined in both step S14 and step S17 that no cycle slip occurs, ending the execution of the method.

[0067] S2: determining the cycle slip numbers of the two frequencies respectively;

[0068] Specifically, the cycle slip number AN1 of frequency 1 and the cycle slip number AN2 of frequency 2 are determined according to formula (14):

[0069]

[0070] wherein, AN WL is the difference between the wide lane ambiguities of the epochs before and after the cycle slip in step S14, which is determined by formula (15):

[0071]

[0072] wherein, N WL is the wide lane ambiguity of the last epoch, is the wide lane ambiguity of the current epoch in which a cycle slip occurs.

[0073] Specifically, in step S2, the cycle slip numbers AN1 and AN2 of the two frequencies are obtained by solving formula (14) and formula (15). Since the cycle slip numbers are floating point solutions due to the whole cycle characteristics of the carrier, the floating point solutions need to be rounded to obtain the final cycle slip numbers [AN1] and [AN2].

[0074] S3: presetting the bias amount corresponding to the cycle slip numbers of the two frequencies, and constructing a search condition for searching the bias amount of the cycle slip numbers of the two frequencies by at least using the test quantity of the geometrically independent combination and the bias amount corresponding to the cycle slip numbers of the two frequencies;

[0075] The specific execution process of step S3 is: using the cycle slip number of the two frequency points determined in step S2, the preset deviation amount corresponding to the cycle slip number of the two frequency points, the test quantity of the geometrically independent combination, and the wavelengths of the two frequency points to construct a search condition for searching the deviation amount of the cycle slip number of the two frequency points.

[0076] In step S3, a corresponding deviation amount is preset for the cycle slip number of each frequency point. The parameters in the search condition constructed in step S3 are composed of the cycle slip number of the two frequency points, the deviation amount corresponding to the cycle slip number, the test quantity of the geometrically independent combination, and the wavelength of the frequency point. The test quantity of the geometrically independent combination refers to the parameter used for judging whether a cycle slip occurs in the geometrically independent combination. As known from step S16, the test quantity of the geometrically independent combination refers to ΔL(i), that is, the difference between the adjacent epoch carrier phase ionospheric residual combination. The judgment condition in the search condition is whether the principle of detecting the cycle slip based on the geometrically independent combination can detect the cycle slip. When the cycle slip cannot be detected, since the parameters in the search condition contain the deviation amount of the cycle slip number, it can be known that the determined cycle slip number needs to be combined with the deviation amount of the cycle slip number to meet the condition that the cycle slip cannot be detected. Therefore, the cycle slip number deviation amount searched by the search condition can be used to update the cycle slip number, so that the cycle slip number is more accurate.

[0077] Specifically, the search condition is constructed as follows:

[0078] wherein λ1 is the wavelength of frequency point 1; λ2 is the wavelength of frequency point 2; ΔN1 is the cycle slip number of frequency point 1 determined in step S2; ΔN2 is the cycle slip number of frequency point 2 determined in step S2; ΔL(i) is the test quantity of the geometrically independent combination determined in step S16, that is, the difference between the adjacent epoch carrier phase ionospheric residual combination; j is the preset deviation amount of the cycle slip number of frequency point 1; and k is the preset deviation amount of the cycle slip number of frequency point 2.

[0079] The deviation amounts j and k of the cycle slip numbers of the two frequency points are introduced in the search condition constructed in step S3. Based on the principle of detecting the cycle slip based on the geometrically independent combination (which can be referred to as the judgment condition for detecting the cycle slip based on the geometrically independent combination in step S17), the judgment condition is set to be less than 0.07, indicating that the cycle slip cannot be detected. When the deviation amounts j and k satisfying the search condition are searched, it indicates that the cycle slip numbers ΔN1 and ΔN2 of the two frequency points need to be combined with the deviation amounts j and k respectively to meet the condition that the cycle slip cannot be detected. Therefore, the searched deviation amounts j and k can be used to update ΔN1 and ΔN2 respectively in step S4, so that they are more accurate.

[0080] S4: using the search condition constructed in step S3 to search the deviation amount corresponding to the cycle slip number of the two frequency points. If the deviation amount is searched, step S5 is executed; if not, step S62 is executed.

[0081] The specific search process in step S4 is: taking the cycle slip numbers of the two frequency points determined in step S2 as the center, searching the deviation amount corresponding to the cycle slip numbers of the two frequency points in the search range with the search condition of step S3 and with a search step.

[0082] Specifically, in step S4, the cycle slip number ΔN1 of frequency point 1 and the cycle slip number ΔN2 of frequency point 2 determined in step S2 are taken as the search center.

[0083] Preferably, the search step in step S4 is 1 cycle slip, and the search range is between 0 cycle slip and 5 cycle slips.

[0084] The error range of the cycle slip numbers solved by the geometric independent combination and the wide-lane combination (i.e. steps S1-S2) will not exceed 5 cycle slips, so it is feasible to search for the deviation amount of the cycle slip numbers in the range between 0 cycle slip and 5 cycle slips. And taking the search step as 1 cycle slip, the search range as between 0 cycle slip and 5 cycle slips, and the number of frequency points as 2, the total search times are 121, the search times are relatively small, and the search process time length and the search difficulty are moderate.

[0085] S5: updating the cycle slip numbers of the two frequency points corresponding to the deviation amount searched in step S4;

[0086] S61: using the cycle slip numbers of the two frequency points updated in step S5 to repair the phase observation values of the two frequency points respectively, and ending the execution of the method;

[0087] Specifically, using the cycle slip numbers to repair the phase observation values is to add the cycle slip numbers to the phase observation values as the final phase observation values.

[0088] In steps S5 and S61, after updating the cycle slip numbers of the two frequency points by the deviation amount searched by the search condition constructed in step S3, the error generated in steps S1-S2 is corrected, so that the cycle slip numbers of the two frequency points updated in step S5 are closer to the true value of the cycle slip numbers, and then using the updated cycle slip numbers to repair the phase observation values of the two frequency points respectively in step S61 will make the phase observation values of the satellite closer to the true value, which is conducive to the further high-precision data processing and application of the satellite.

[0089] S62: using the cycle slip numbers of the two frequency points determined in step S2 to repair the phase observation values of the two frequency points respectively, and ending the execution of the method.

[0090] If no satisfying deviation amount is searched based on the constructed search condition in step S3, it means that the cycle slip numbers determined in step S2 do not need to be updated, the error is small, and it can be considered that the cycle slip numbers are relatively close to the true value, so in step S62, the cycle slip numbers of the two frequency points determined in step S2 can be used to repair the phase observation values of the two frequency points respectively, and the execution of the method is ended.

[0091] As Figure 2 shown, in one preferred embodiment, the overall flow of the method provided by the present embodiment is as follows:

[0092] Step S11 is performed: Construct the wide-lane combined pseudorange observation value P WL and the carrier observation value L WL , see equations (5), (6);

[0093] Step S12 is performed: Simultaneously solve equations (5) and (6) in step S11 to obtain the wide-lane ambiguity N WL , see equation (7);

[0094] Step S13 is performed: Using a sliding average model, use a sliding window of width m adjacent to the current epoch to calculate the average value and variance of the i-epoch wide-lane ambiguity, see recursive equations (8) and (9);

[0095] Step S14 is performed: According to recursive equations (8) and (9) of step S13, compare the average values of the wide-lane ambiguities of the current epoch i and epoch i+1, and determine whether a cycle slip has occurred according to the equation set (10);

[0096] Step S15 is performed: Construct the carrier phase ionospheric residual combination L GF of the geometrically independent combination and the pseudorange ionospheric combination P GF of the geometrically independent combination, see equations (11) and (12);

[0097] Step S16 is performed: Subtract the carrier phase ionospheric residual combinations L GF of adjacent epochs to obtain the difference ΔL(i) between the carrier phase ionospheric residual combinations of adjacent epochs, see equation (13);

[0098] Step S17 is performed: Determine whether a cycle slip has occurred according to the difference ΔL(i) between the carrier phase ionospheric residual combinations of adjacent epochs determined in step S16;

[0099] Step S18 is performed: If it is determined in both step S14 and step S17 that no cycle slip has occurred, then the execution of the method is ended; if it is determined in either step S14 or step S17 that a cycle slip has occurred, then step S2 is performed;

[0100] Step S2 is performed: Determine the number of cycle slips for the two frequencies respectively; specifically, determine the number of cycle slips ΔN1 for frequency 1 and the number of cycle slips ΔN2 for frequency 2 according to equation (14); solve for the number of cycle slips ΔN1 and ΔN2 on the two frequencies according to equations (14) and (15); due to the integer characteristic of the carrier, the floating-point solution of the number of cycle slips is obtained, so the floating-point solution needs to be rounded, i.e., rounded to the nearest integer to obtain the final number of cycle slips [ΔN1] and [ΔN2];

[0101] Step S3 is performed: presetting the deviation amount corresponding to the cycle slip number of the two frequencies; and constructing a search condition as follows:

[0102] Step S4 is performed: taking the cycle slip number ΔN1 of the frequency 1 and the cycle slip number ΔN2 of the frequency 2 determined in step S2 as the search center, taking 1 cycle slip as the search step, taking the search range between 0 cycle slip and 5 cycle slip, and searching for the deviation amount j and k based on the search condition constructed in step S3; if the deviation amount is searched, step S5 is performed; if the deviation amount is not searched, step S62 is performed.

[0103] Step S5 is performed: updating the cycle slip numbers of the two frequencies by using the searched deviation amount in step S4.

[0104] Step S61 is performed: adding the cycle slip numbers of the two frequencies updated in step S5 to the phase observation values of the two frequencies respectively to obtain the final phase observation values of the two frequencies, and ending the execution of the method.

[0105] Step S62 is performed: adding the cycle slip numbers of the two frequencies determined in step S2 to the phase observation values of the two frequencies respectively to obtain the final phase observation values of the two frequencies, and ending the execution of the method.

[0106] The improved double-frequency real-time cycle slip detection and repair method provided in the embodiment is an improvement on the existing TurboEdit method for satellite carrier phase cycle slip detection. After detecting that a cycle slip occurs and determining the cycle slip numbers of the two frequencies, a search condition is constructed by using the test quantity of the geometric independent combination and the related parameters of the two frequencies, which is used to search for the deviation amount of the cycle slip numbers of the two frequencies. The cycle slip numbers of the two frequencies are updated by using the searched deviation amount. The updated cycle slip numbers are more accurate and have smaller errors. The updated cycle slip numbers are used to repair the phase observation values of the two frequencies, so that the phase observation values of the satellite are more accurate, which is beneficial to further high-precision data processing and application of the satellite.

[0107] Specifically, the experimental data of the method provided in the embodiment is as follows: actual carrier observation values and pseudo-range observation values with L1 and L2 two frequencies are collected. In this data, the complete data arc segment of satellite No. 29 from entering the field of view to leaving the field of view is taken. A cycle slip is artificially inserted at an epoch without cycle slip.

[0108] Table 1 is a comparison of repair effects after artificially inserting a cycle slip at some epochs of the above data. In Table 1, “true value” is the true value of the artificially inserted cycle slip, “the method” is the cycle slip value repaired by the method described in the embodiment, and “direct rounding method” is the cycle slip value obtained by the original direct rounding method in the TurboEdit method.

[0109] Table 1

[0110]

[0111]

[0112] From the data in Table 1, it can be seen that the cycle slip value obtained by the direct rounding method has a difference of 1-5 cycles from the true cycle slip value, while the cycle slip value obtained by the method provided in the embodiment has no difference from the true cycle slip value, and the cycle slip value calculation is completely correct.

[0113] Based on the same idea as the above-mentioned improved dual-frequency real-time cycle slip detection and repair method, the embodiment also provides an improved dual-frequency real-time cycle slip detection and repair system, as shown in Figure 3 The system comprises:

[0114] The cycle slip detection module 100 is configured to detect whether cycle slips occur in two frequency points in the phase observations of the satellite by using the wide-lane combination and the geometry-independent combination.

[0115] The cycle slip determination module 200 is configured to determine the number of cycle slips of the two frequency points respectively when the cycle slip detection module detects that cycle slips occur.

[0116] The search module 300 is configured to preset the bias corresponding to the number of cycle slips of the two frequency points determined by the cycle slip determination module 200, construct a search condition for searching the bias of the number of cycle slips of the two frequency points by using at least the test quantity of the geometry-independent combination and the bias corresponding to the number of cycle slips of the two frequency points, search the bias of the number of cycle slips of the two frequency points by using the search condition, and if the search is successful, update the number of cycle slips of the two frequency points determined by the cycle slip determination module 200 by using the searched bias, and repair the phase observation values of the two frequency points respectively by using the updated number of cycle slips of the two frequency points.

[0117] Specifically, the specific process in which the search module 300 searches the bias of the number of cycle slips of the two frequency points by using the search condition is as follows:

[0118] The search module 300 is configured to search the bias of the number of cycle slips of the two frequency points by using the constructed search condition in the search range with the number of cycle slips of the two frequency points as the center and with a search step length.

[0119] Specifically, the specific process in which the search module 300 constructs the search condition for searching the bias of the number of cycle slips of the two frequency points by using at least the test quantity of the geometry-independent combination and the bias corresponding to the number of cycle slips of the two frequency points is as follows:

[0120] The search module 300 is configured to construct a search condition for searching the bias amount of the cycle slip numbers of the two frequencies by using the cycle slip numbers of the two frequencies determined by the cycle slip determination module 200, the bias amount of the cycle slip numbers of the two frequencies, the test quantity of the geometrically independent combination and the wavelengths of the two frequencies.

[0121] Specifically, the search condition constructed by the search module 300 is: wherein λ1 is the wavelength of the first frequency, λ2 is the wavelength of the second frequency, ΔN1 is the cycle slip number of the first frequency, ΔN2 is the cycle slip number of the second frequency, ΔL(i) is the test quantity of the geometrically independent combination, j is the bias amount of the cycle slip number of the first frequency, and k is the bias amount of the cycle slip number of the second frequency.

[0122] Preferably, the search step of the search module 300 when searching based on the constructed search condition is 1 cycle slip;

[0123] Preferably, the search range of the search module 300 when searching based on the constructed search condition is between 0 cycle slip and 5 cycle slips.

[0124] Preferably, the specific process of the cycle slip determination module 200 when respectively determining the cycle slip numbers of the two frequencies is:

[0125] The cycle slip determination module 200 determines the floating point solution of the cycle slip numbers of the two frequencies, and takes the integer of the floating point solution of the cycle slip numbers of the two frequencies as the cycle slip numbers of the two frequencies.

[0126] In the above-mentioned embodiments of the improved double-frequency real-time cycle slip detection and repair system, the logical division of each functional module is only used as an example. In actual applications, the above-mentioned functions can be completed by different functional modules according to needs, for example, due to the configuration requirements of hardware or the implementation of software. The internal structure of the improved double-frequency real-time cycle slip detection and repair system can be divided into functional modules different from the above-mentioned content, but can complete all the functions described above. Secondly, the execution process and other contents of the modules of the above-mentioned example of the improved double-frequency real-time cycle slip detection and repair system are based on the same concept as the aforementioned improved double-frequency real-time cycle slip detection and repair method. The principles and technical effects brought by them are the same as those of the aforementioned improved double-frequency real-time cycle slip detection and repair method. For specific content, please refer to the description of the method embodiments, which will not be repeated here.

[0127] The embodiment also provides a computer device including a memory and a processor. The memory stores a computer program. The processor implements the above-mentioned improved double-frequency real-time cycle slip detection and repair method when executing the computer program.

[0128] The embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the improved dual-frequency real-time cycle slip detection and repair method.

[0129] Obviously, the above embodiments of the present application are only examples for clearly illustrating the technical solutions of the present application, and are not intended to limit the specific implementation of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the claims of the present application should be included in the protection scope of the claims of the present application.

Claims

1. An improved dual-frequency real-time cycle-slip detection and repair method, characterized in that, The method comprises the following steps: It is detected whether any two frequency points in phase observations of a satellite occur cycle slip by using wide lane combination and geometry-independent combination, and if so, cycle slip numbers of the two frequency points are determined respectively; A bias corresponding to the cycle slip numbers of the two frequency points is preset, and a search condition for searching the bias corresponding to the cycle slip numbers of the two frequency points is constructed by using at least a test value of the geometry-independent combination and the bias corresponding to the cycle slip numbers of the two frequency points; the bias corresponding to the cycle slip numbers of the two frequency points is searched by using the search condition, and if searched, the cycle slip numbers of the two frequency points are updated by using the searched bias, and the phase observations of the two frequency points are repaired respectively by using the updated cycle slip numbers of the two frequency points. The constructed search condition is: Wherein, λ1 is the wavelength of the first frequency point, λ2 is the wavelength of the second frequency point, ΔN1 is the cycle slip number of the first frequency point, ΔN2 is the cycle slip number of the second frequency point, ΔL(i) is the test value of the geometry-independent combination, j is the preset bias of the cycle slip number of the first frequency point, and k is the preset bias of the cycle slip number of the second frequency point.

2. The improved dual-frequency real-time cycle-slip detection and repair method according to claim 1, wherein, The bias corresponding to the cycle slip numbers of the two frequency points is searched by using the search condition, specifically: The bias corresponding to the cycle slip numbers of the two frequency points is searched by using the search condition within a search range with the cycle slip numbers of the two frequency points as the center and a search step.

3. The improved dual-frequency real-time cycle-slip detection and repair method according to claim 2, wherein, The search condition for searching the bias corresponding to the cycle slip numbers of the two frequency points is constructed by using at least the test value of the geometry-independent combination and the bias corresponding to the cycle slip numbers of the two frequency points, specifically: The search condition for searching the bias corresponding to the cycle slip numbers of the two frequency points is constructed by using the cycle slip numbers of the two frequency points, the bias corresponding to the cycle slip numbers of the two frequency points, the test value of the geometry-independent combination, and the wavelengths of the two frequency points.

4. The improved dual-frequency real-time cycle-slip detection and repair method according to any one of claims 2-3, characterized in that, The search step is 1 cycle slip.

5. The improved dual-frequency real-time cycle-slip detection and repair method according to any one of claims 2-3, characterized in that, The search range is between 0 cycle slip and 5 cycle slip.

6. The improved dual-frequency real-time cycle-slip detection and repair method according to any one of claims 1-3, characterized in that, The cycle slip numbers of the two frequency points are determined respectively, specifically: a floating point solution of the cycle slip numbers of the two frequency points is determined, and the floating point solution of the cycle slip numbers of the two frequency points is rounded to the cycle slip numbers of the two frequency points.

7. The improved system of dual-frequency real-time cycle-slip detection and repair method according to claim 1, wherein, The method comprises the following steps: A cycle slip detection module is configured to detect whether two frequency points in phase observations of a satellite occur cycle slip by using wide lane combination and geometry-independent combination; A cycle slip determination module is configured to determine cycle slip numbers of the two frequency points respectively when the cycle slip detection module detects that cycle slip occurs; A search module is configured to preset a bias corresponding to the cycle slip numbers of the two frequency points determined by the cycle slip determination module, construct a search condition for searching the bias corresponding to the cycle slip numbers of the two frequency points by using at least a test value of the geometry-independent combination and the bias corresponding to the cycle slip numbers of the two frequency points, search the bias corresponding to the cycle slip numbers of the two frequency points by using the search condition, and if searched, update the cycle slip numbers of the two frequency points determined by the cycle slip determination module by using the searched bias, and repair the phase observations of the two frequency points respectively by using the updated cycle slip numbers of the two frequency points.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor implements the improved double-frequency real-time cycle slip detection and repair method of any one of claims 1-6 when executing the computer program.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the improved double-frequency real-time cycle slip detection and repair method of any one of claims 1-6.

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