Single epoch double difference ambiguity resolution method

Abstract

The present application relates to a kind of single epoch double-difference integer ambiguity fast solution confirmation method.The method is used for the satellite navigation system of multi-frequency signal, comprising: determining the optimal solution of the double-difference observation equation of the carrier phase of main frequency signal and the corresponding variance matrix;Determine the point accuracy of the optimal solution;The point accuracy is compared with the threshold value corresponding to the main frequency signal based on the satellite navigation system of the multi-frequency signal;The candidate group of the double-difference integer ambiguity of the main frequency signal corresponding to the optimal solution of the point accuracy superior to the threshold value is determined as the optimal group.The embodiments of the present application consider that the satellite navigation system has multi-frequency signal characteristics, without the traditional complex Ratio test, just need to use simple consistency confirmation, and integer ambiguity can be quickly determined, provide a kind of reliable, fast solution confirmation method with fast solution efficiency and simple and effective for high-frequency data single epoch double-difference integer ambiguity fast determination.

Description

Technical Field

[0001] This invention relates to the field of double-difference integer ambiguity resolution technology, and in particular to a single-epoch double-difference integer ambiguity resolution verification method. Background Technology

[0002] In the field of high-precision satellite positioning, GNSS carrier phase measurement is generally used. The carrier phase signal is a periodic sinusoidal signal, but GNSS carrier phase measurement can only measure a portion less than one wavelength, thus introducing integer uncertainty, i.e., integer ambiguity (also called integer unknown). Rapid determination of integer ambiguity is one of the keys to high-precision real-time dynamic satellite positioning. When determining integer ambiguity, after identifying the optimal solution corresponding to the dominant frequency signal, current methods typically use a Ratio test to verify the reliability of this optimal solution. After passing the test, this optimal solution is then used to determine the double-difference integer ambiguity for all satellite pairs. The Ratio test is relatively complex and, to some extent, slows down the rapid determination of single-epoch double-difference integer ambiguity. Furthermore, the critical value for the Ratio test is usually set to 3.0, which is an empirical value. Some literature suggests that values ​​between 1.8 and 3.0 are acceptable, but there is no definitive value. For practical applications with high reliability requirements, this carries the possibility of "accepting false positives" or "discarding true positives."

[0003] The description of the background technology in this document is only for the convenience of understanding the present invention, and does not imply that these technologies are known to those skilled in the art, nor should they be taken for granted as prior art. Summary of the Invention

[0004] The present invention is made in view of the above-mentioned situation of the prior art, in order to solve one or more problems existing in the prior art, and at least provide an advantageous alternative.

[0005] According to one aspect of the present invention, a method for rapid resolution and confirmation of single-epoch double-difference integer ambiguity is provided. This method is used in a multi-frequency signal satellite navigation system, and includes: determining the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation for the main frequency signal; determining the position accuracy of the optimal solution; comparing the position accuracy with a threshold corresponding to the main frequency signal of the satellite navigation system based on the multi-frequency signal; and determining the candidate group of double-difference integer ambiguities of the main frequency signal corresponding to the optimal solution with a position accuracy better than the threshold as the optimal group.

[0006] According to some embodiments of the present invention, the determination efficiency of single-epoch double-difference integer ambiguity can be improved without using the traditional Ratio test method, and can at least be regarded as a useful option. Attached Figure Description

[0007] The invention can be better understood by referring to the accompanying drawings, which are illustrative and not intended to limit the scope of protection of the invention.

[0008] Figure 1 A schematic flowchart of a method for rapid resolution and confirmation of single-epoch double-difference integer ambiguity according to an embodiment of the present invention is shown.

[0009] Figure 2 A schematic flowchart of a method for determining the optimal solution of the carrier phase double-difference observation equation of the main frequency signal and the corresponding variance matrix according to an embodiment of the present invention is shown. Detailed Implementation

[0010] Figure 1 A schematic flowchart illustrating a method for rapid resolution and confirmation of single-epoch double-difference integer ambiguity according to an embodiment of the present invention is shown. Figure 1 As shown, according to an embodiment of the present invention, a method for rapid resolution and confirmation of single-epoch double-difference integer ambiguity first determines the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation of the main frequency signal in step S100. Then, in step S200, the point accuracy of the optimal solution is determined. Next, in step S300, the point accuracy is compared with a threshold corresponding to the main frequency signal of the satellite navigation system based on the multi-frequency signal. Finally, in step S400, the candidate group of double-difference integer ambiguities of the main frequency signal corresponding to the optimal solution with point accuracy better than the threshold is determined as the optimal group. This method can be implemented using a satellite positioning rover (hereinafter also referred to as a rover or monitoring station, which can be a GNSS monitoring station) and a processor communicating with the monitoring station. The monitoring station can be fixedly installed, for example, on the top of a high-rise building. The monitoring station is mainly used for data acquisition of satellite navigation signals. Steps S100 to S400 of the method are all implemented by the processor. The monitoring station and the processor can be separate or integrated. When implementing steps S100 to S400, a memory can be used in conjunction.

[0011] Step S100, which determines the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation for the main frequency signal, can be implemented using other methods known now or in the future to those skilled in the art. For example, the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation for the main frequency signal can be determined using the least squares parameter estimation indirect adjustment method.

[0012] Figure 2 A schematic flowchart illustrating a method for determining the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation of the dominant frequency signal according to an embodiment of the present invention is shown. Figure 2As shown, according to one embodiment of the present invention, the method for determining the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation of the main frequency signal first determines the main frequency signal and the auxiliary frequency signal in step S110. The main frequency signal is mainly used for positioning, and the auxiliary frequency signal is mainly used for the rapid resolution of double-difference integer ambiguity of the cross-constrained main frequency signal. According to one embodiment, the first frequency signal of a multi-frequency satellite navigation system can be determined as the main frequency signal, while frequency signals other than the main frequency signal can be determined individually or in linear combinations as auxiliary frequency signals. Alternatively, multiple frequency signals of a single system (e.g., B1I, B1C, B2a, B2b, B3I of a BDS system or L1, L2, L5 of a GPS system) can be linearly combined in a wide-lane combination, narrow-lane combination, or ultra-wide-lane combination to form a new combined frequency signal, which is determined as the main frequency signal, while frequency signals other than the main frequency signal can be determined individually or in linear combinations as auxiliary frequency signals. According to one embodiment, a single original frequency signal with high carrier phase observation accuracy, or a new combined frequency signal formed by linearly combining multiple original frequency signals, is determined as the main frequency signal.

[0013] Then, in step S120, the carrier phase double-difference observation equations for the main frequency signal and the carrier phase double-difference observation equations for the auxiliary frequency signal are constructed.

[0014] According to one implementation, the carrier phase double-difference observation equations for the primary frequency signal and the secondary frequency signal are established as follows:

[0015]

[0016] Where λ is the wavelength of the frequency signal, including the wavelengths of the primary frequency signal and the secondary frequency signal. When λ is the wavelength of the primary frequency signal, the established equation is the carrier phase double-difference observation equation for the primary frequency signal. When λ is the wavelength of the secondary frequency signal, the established equation is the carrier phase double-difference observation equation for the secondary frequency signal.

[0017] Wherein, subscript b represents the base station, subscript r represents the rover station, superscript i represents the reference satellite with the largest satellite elevation angle, and superscript j represents satellites other than the aforementioned reference satellite, j = 1, 2, ..., i-1, i+1, ..., k. This represents the carrier phase double-difference observation. This represents the difference between the observed inter-satellite distance and the satellite-to-Earth distance. and This represents the cosine coefficient of the satellite-to-Earth distance direction. and Let r be the three-dimensional coordinate correction value for rover r. This represents the double-difference integer ambiguity, where k is a positive integer representing the total number of satellites observed in this epoch.

[0018] Next, in step S130, the candidate group of double-difference integer ambiguity of the main frequency signal is determined by using the carrier phase double-difference observation equation of the auxiliary frequency signal.

[0019] According to one implementation, candidate groups for the double-difference integer ambiguity of the main frequency signal are determined as follows:

[0020] First, calculate the initial value of the double-difference integer ambiguity of the secondary frequency signal as follows:

[0021]

[0022] Wherein, subscript b represents the base station, subscript r represents the rover station, superscript i represents the reference satellite with the largest satellite elevation angle, and superscript j represents satellites other than the aforementioned reference satellite, j = 1, 2, ..., i-1, i+1, ..., k. Represents the auxiliary frequency signal f A The initial value of the double-difference integer ambiguity. Represents the auxiliary frequency signal f A The difference between the observed inter-satellite distance and the satellite-to-Earth distance. Represents the auxiliary frequency signal f A Double-difference carrier phase observations, Auxiliary frequency signal f A The wavelength.

[0023] Secondly, using this initial value, candidate values ​​for the double-difference integer ambiguity of the secondary frequency signal are determined:

[0024] For satellite pairs i and j,

[0025]

[0026] Where i is the reference satellite, j is a satellite other than the reference satellite, j = 1, 2, ..., i-1, i+1, ..., k, E Length The band length of the error band for satellite pairs i and j is, according to one implementation method, estimated using the mean square error of the pseudorange difference observations multiplied by 1. Construction. Specifically, it can be determined as follows:

[0027]

[0028] in, This is an estimate of the standard error of the pseudorange difference observations. The wavelength of the auxiliary frequency signal is l = 2 to 5, and int(·) represents the integer operation.

[0029] Error estimation using pseudorange difference observations The construction can increase the accuracy of the error bands of satellite pairs i and j, wherein the pseudorange differential observations can be single-difference observations or double-difference observations.

[0030] In the above formula, Auxiliary frequency signal f A Candidate values ​​for double-difference integer ambiguity. There are w candidate groups of double-difference integer ambiguities with integer properties.

[0031] Secondly, using the following relational formula, of Determine the main frequency signal f M Candidate values ​​for double-difference integer ambiguity:

[0032]

[0033] in:

[0034] Where u represents the error band. Main frequency signal f M Residual error and measurement noise after inter-satellite double difference Auxiliary frequency signal f A Residual error and measurement noise after inter-satellite double difference The wavelength of the main frequency signal. The wavelength of the secondary frequency signal. Auxiliary frequency signal f A Candidate values ​​for double-difference integer ambiguity, E Wide This refers to the bandwidth of the error band for satellite pairs i and j.

[0035] According to one embodiment, for multi-frequency signals, preferably, a primary frequency signal and an auxiliary frequency signal are determined, such that the auxiliary frequency signal f A Corresponding wavelength With the main frequency signal f M Corresponding wavelength The ratio To keep it as small as possible, where C is the speed of light. In other words, for multi-frequency signals, determine the primary frequency signal and the secondary frequency signal, such that the frequency f corresponding to the primary frequency signal is... M The frequency f corresponding to the auxiliary frequency signal A The ratio should be as small as possible. This ensures that among a given set of w candidate groups with integer-valued double-difference integer ambiguities... In this approach, based on the cross-search (or constraint) of the error band u, a smaller number of candidate groups of double-difference integer ambiguities with integer properties (v) can be obtained.

[0036] According to one implementation, the baseline length L formed between the base station b and the rover r can be used. br The bandwidth of the error band is constructed. It is determined according to one implementation method as follows:

[0037]

[0038] Using this implementation, due to the use of baseline length L br This allows for a better determination of the error band bandwidth, increasing the accuracy of the satellite's error band construction for i and j.

[0039] Main frequency signal f M Candidate values ​​for double-difference integer ambiguity.

[0040] There are v candidate groups of double-difference integer ambiguities with integer properties.

[0041] Finally, the candidate values ​​for the double-difference integer ambiguity of the main frequency signal of all satellite pairs in the single epoch data are represented as follows:

[0042]

[0043] Perform on the candidate values By arranging and combining groups, candidate groups of double-difference integer ambiguities of the main frequency signals of all satellite pairs in the single epoch data are obtained, where t represents the total number of candidate groups.

[0044] Then, in step S140, based on the candidate group of the double-difference integer ambiguity, the optimal solution and the corresponding variance matrix of the carrier phase double-difference observation equation of the main frequency signal are determined. According to one embodiment, the optimal solution and the corresponding variance matrix of the double-difference integer ambiguity of the main frequency signal are determined as follows:

[0045] First, the candidate groups of t for the double-difference integer ambiguity of the main frequency signal are substituted sequentially into the double-difference observation equation of the carrier phase of the main frequency. According to the least squares parameter estimation indirect adjustment method, the error equation of the corresponding double-difference observation equation of the carrier phase of the main frequency signal is:

[0046]

[0047] Written in matrix form:

[0048]

[0049] in,

[0050] Subscript b indicates the base station, subscript r indicates the rover station, superscript i indicates the reference satellite with the largest elevation angle, and superscript j indicates a satellite other than the reference satellite, j = 1, 2, ..., i-1, i+1, ..., k. These are carrier phase double-difference observations. The wavelength of the main frequency signal. Candidate groups for the double-difference integer ambiguity of the main frequency signal; The difference between the observed inter-satellite distance and the satellite-to-Earth distance is given. and The cosine coefficient of the satellite-to-Earth distance direction. and Let r be the three-dimensional coordinate correction value for rover r. The residuals of the carrier phase double-difference observations, The constant term of the carrier phase double-difference observation equation for the main frequency signal;

[0051] Secondly, based on the least squares parameter estimation indirect adjustment method, the post-hoc unit weighted variance estimate of the carrier phase double-difference observation equation of the main frequency signal is calculated as follows:

[0052]

[0053] Where: k is the total number of observed satellites in the single epoch data, k≥5, and P is the weight matrix of the carrier phase double difference observations in the single epoch data.

[0054] From t candidate groups, t post-hoc unit weighted variance estimates can be calculated, represented by a set as follows:

[0055] Next, for the set Sort the elements in the array from smallest to largest to obtain the smallest posterior unit weighted variance estimate.

[0056]

[0057] Then the candidate group corresponding to m is determined as the optimal group, that is

[0058] Based on the optimal set, the optimal solution for rover station r can be obtained by the least squares parameter estimation indirect adjustment method:

[0059]

[0060] The variance matrix corresponding to the optimal solution is:

[0061]

[0062] in, Estimate the single-epoch satellite positioning position parameters and their variance matrix for rover r; Let r be the single-epoch satellite positioning position parameter corrections for rover r and its corresponding variance matrix; P is the weight matrix of the carrier phase double-difference observations in the single-epoch data. The initial values ​​of the parameters to be estimated for the single-epoch satellite positioning of rover r are given. The estimated error in the X-direction of satellite positioning for rover r in a single epoch is given. The estimated error in the Y-direction of single-epoch satellite positioning for rover r. The Z-axis mean square error estimate for single-epoch satellite positioning of rover r. Estimate the covariance between the X and Y directions of the single-epoch satellite positioning of rover r. Estimate the covariance between the X and Z directions of the single-epoch satellite positioning of rover r. Estimate the covariance between the Y and Z directions of the single-epoch satellite positioning of rover r.

[0063] According to one implementation method This can be calculated using pseudorange differential positioning of coarse-coded observations in single-epoch data. According to another implementation, for practical applications such as high-rise building tilt monitoring, the location of the monitoring point at the top of the high-rise building is provided by a reference known value (i.e., the fixed installation location of the monitoring station, which can be obtained using high-precision satellite positioning control and measurement network technology):

[0064]

[0065] Among them, X M =[B M L M H M ] T The reference known value for the location of the monitoring point on the top of the high-rise building (i.e., the location where the monitoring station is fixedly installed).

[0066] If the positioning accuracy of the rover is measured using the expression in the station-centered coordinate system of the rover r, the variance matrix of the estimated satellite positioning position parameters of the rover in the station-centered coordinate system is used... This can be expressed as follows, and from the variance-covariance propagation law, we can obtain:

[0067]

[0068] In the formula, Where: B0 and L0 are the geodetic latitude and geodetic longitude corresponding to the known reference values ​​of the location of the rover r, respectively; Estimate the northward mean square error of single-epoch satellite positioning for the rover station. The eastward mean square error estimate for single-epoch satellite positioning of the rover station. To estimate the elevation mean square error of the single-epoch satellite positioning of the rover station. Estimate the covariance between the northward and eastward directions for single-epoch satellite positioning of the rover station. Estimate the covariance between the northward and elevation directions of the rover's single-epoch satellite positioning. This is the estimated covariance between the eastward and elevation directions of the single-epoch satellite positioning of the rover station.

[0069] Back Figure 1 In step S200, the point accuracy of the optimal solution is determined.

[0070] According to one implementation, the point accuracy of the optimal solution is determined as follows:

[0071] From the variance matrix The accuracy of this location is determined as follows:

[0072]

[0073] in, The point accuracy of satellite positioning for rover r over a single epoch.

[0074] According to another implementation, the point accuracy of the optimal solution is determined as follows:

[0075] From the variance matrix Then according to get

[0076] in, B0 and L0 are the geodetic latitude and longitude of the location of the rover r, respectively.

[0077] Then, the accuracy of this point is determined as follows:

[0078]

[0079] in, Let r be the positional accuracy of the rover. The estimated northward mean square error of single-epoch satellite positioning for rover r. The estimated eastward mean square error of single-epoch satellite positioning for rover r. The estimated elevation error of the single-epoch satellite positioning for rover r. Estimate the covariance between the northward and eastward directions for the single-epoch satellite positioning of rover r. Estimate the covariance between the northward and elevation directions of the single-epoch satellite positioning of rover r. This is the estimated covariance between the eastward and elevation directions of the single-epoch satellite positioning of rover r.

[0080] Then, in step S300, the position accuracy is compared with the threshold corresponding to the main frequency signal of the satellite navigation system based on the multi-frequency signal.

[0081] According to one implementation, the threshold is determined based on the wavelength or frequency corresponding to the main frequency signal of the multi-frequency signal-based satellite navigation system as follows:

[0082]

[0083] in, The threshold value is... f is the wavelength corresponding to the main frequency signal of the multi-frequency signal-based satellite navigation system. M Let C be the frequency corresponding to the main frequency signal of the satellite navigation system based on multi-frequency signals, and C be the speed of light.

[0084] Furthermore, according to experimental results, for the first frequency of current multi-frequency satellite navigation systems (GPS L1 frequency 1575.420MHz, BDS B1I frequency 1561.098MHz, GLONASS L1 frequency 1598.0625~1609.3125MHz, and Galileo E1 frequency 1575.420MHz), this threshold can be taken in the range of 0.1613~0.1663 meters.

[0085] According to one implementation, the primary frequency signal of the multi-frequency signal-based satellite navigation system is the narrow-lane combined observation frequency, and the threshold is set to 0.092 meters. Based on calculations, setting this value as the threshold can well accommodate the linear combined observation frequencies of current multi-frequency signal-based satellite navigation systems, and achieves a good balance between reliability verification and false detection rate.

[0086] In step S300, the point accuracy obtained in step S200 is compared with the threshold corresponding to the main frequency signal of the multi-frequency signal satellite navigation system. If the comparison result is that the point accuracy is greater than the threshold, i.e. the accuracy is insufficient, the optimal solution is discarded, and the process returns to step S100 to perform the fast double-difference integer ambiguity resolution confirmation of the next single-epoch data.

[0087] Finally, in step S400, when the comparison result is that the point accuracy is less than the threshold, the candidate group of the double-difference integer ambiguity of the main frequency signal corresponding to the optimal solution with point accuracy better than the threshold is determined as the optimal group.

[0088] According to one embodiment, the method further includes substituting the optimal solution into the carrier phase double-difference observation equation of the main frequency signal to determine the rounding group of the double-difference integer ambiguity of the main frequency signal; and confirming the consistency between the optimal group and the rounding group to determine the single-epoch double-difference integer ambiguity.

[0089] According to one implementation, the rounding group of the double-difference integer ambiguity of the main frequency signal is determined as follows:

[0090] First, the optimal group of double-difference integer ambiguities of the determined main frequency signal is... Substituting the carrier phase double-difference observation equation of the main frequency signal, and using the least squares parameter estimation indirect adjustment method, the three-dimensional coordinate correction of the rover r is calculated. Correct the three-dimensional coordinates Substituting back into the carrier phase double-difference observation equation for the main frequency signal, we can solve for the real solution of the double-difference integer ambiguity of the main frequency signal as follows:

[0091]

[0092] Then, the real number solution is rounded according to the principle of "rounding up if odd, not if even", to obtain the rounded group of the double-difference integer ambiguity of the main frequency signal as follows:

[0093]

[0094] in, The integer group of the double-difference integer ambiguity of the main frequency signal is used, and int(·) is the integer operator.

[0095] According to one implementation, the consistency between the optimal group and the rounding group is confirmed as follows.

[0096] For the double-difference integer ambiguity of satellite pairs i and j in the single-epoch data, confirm the optimal group. In the rounding group Whether they are equal, j = 1, 2, ..., i-1, i+1, ..., k, where k ≥ 5;

[0097] if and If they are equal, it is determined that the fast resolution of the double-difference integer ambiguity of satellite pairs i and j in the single-epoch data has been confirmed, indicating that the fast resolution of the double-difference integer ambiguity of satellite pairs i and j has been successful.

[0098] if and If they are not equal, it is determined that the fast solution of the double difference integer ambiguity of satellite pairs i and j in the single era data has not passed the confirmation, indicating that the fast solution of the double difference integer ambiguity of satellite pairs i and j has failed.

[0099] According to one implementation, the double-difference integer ambiguity of the satellite pair in the confirmed single-epoch data is obtained as follows: j1=1,2,…,i-1,i+1,…,s, where s is the number of satellite pairs in the confirmed single-epoch data, and s≤k.

[0100] According to one embodiment of the present invention, the method can be applied to real-time positioning with a GNSS receiver data sampling rate of not less than 1 Hz.

[0101] The embodiments of the present invention take into account the multi-frequency signal characteristics of satellite navigation systems and preferentially select the phase observation values ​​of the primary and secondary frequency carriers. There is no need to perform the traditional complex ratio test. Only a simple consistency confirmation is required to quickly determine the integer ambiguity. This provides a reliable, efficient and simple fast solution confirmation method for the rapid determination of single-epoch double-difference integer ambiguity of high-frequency data.

[0102] The above detailed description of the invention is merely intended to provide those skilled in the art with further information for carrying out preferred aspects of the invention, and does not limit the scope of the invention. Only the claims are used to define the scope of protection of the invention. Therefore, the combination of features and steps in the foregoing detailed description is not necessary for carrying out the invention in the broadest possible sense, and is alternatively taught only for representative embodiments of the invention as described in a particularly detailed description. Furthermore, various different features taught in the specification can be combined in various ways to obtain additional useful embodiments of the invention; however, these ways are not specifically exemplified.

Claims

1. A method for rapid resolution and confirmation of single-epoch double-difference integer ambiguity, used in a multi-frequency signal satellite navigation system, the method comprising: Determine the optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation for the main frequency signal; Determine the point accuracy of the optimal solution; The accuracy of the location is compared with the threshold corresponding to the main frequency signal of the satellite navigation system based on the multi-frequency signal; The candidate group of double-difference integer ambiguity of the main frequency signal corresponding to the optimal solution with point accuracy better than the threshold is determined as the optimal group. The optimal solution and corresponding variance matrix of the carrier phase double-difference observation equation for the main frequency signal are determined as follows: For multi-frequency signals, determine the primary frequency signal and the secondary frequency signal; Establish the carrier phase double-difference observation equations for the main frequency signal and the auxiliary frequency signal; By using the carrier phase double-difference observation equation of the secondary frequency signal, candidate groups for the double-difference integer ambiguity of the main frequency signal are determined. By substituting each candidate group into the carrier phase double-difference observation equation of the main frequency signal, the optimal solution and the corresponding variance matrix of the carrier phase double-difference observation equation of the main frequency signal are determined. The method further includes: Substituting the optimal solution into the carrier phase double-difference observation equation of the main frequency signal, the integer group of the double-difference integer ambiguity of the main frequency signal is determined; and Confirm the consistency between the optimal group and the integer group, and determine the single-epoch double-difference integer ambiguity.

2. The method according to claim 1, characterized in that, Candidate groups for the double-difference integer ambiguity of the main frequency signal are determined as follows: First, using the carrier phase double-difference observation equation of the secondary frequency signal, the initial value of the double-difference integer ambiguity of the secondary frequency signal is calculated as follows: in, Represents the auxiliary frequency signal f A The initial value of the double-difference integer ambiguity. Represents the auxiliary frequency signal f A The difference between the observed inter-satellite distance and the satellite-to-Earth distance. Represents the auxiliary frequency signal f A carrier phase double-difference observations, Auxiliary frequency signal f A The wavelength, subscript b indicates the satellite positioning reference station, and subscript r indicates the satellite positioning rover station; Secondly, using the initial value, candidate values ​​for the double-difference integer ambiguity of the auxiliary frequency signal are determined: For satellite pairs i and j, Where i is the reference satellite, j is a satellite other than the reference satellite, j = 1, 2, ..., i-1, i+1, ..., k, E Length The length of the error band for satellite pairs i and j. Auxiliary frequency signal f A Candidate values ​​for double-difference integer ambiguity. w is the number of candidate values; Secondly, using the following relational formula, of Determine the main frequency signal f M Candidate values ​​for double-difference integer ambiguity: in: Where u represents the error band. Main frequency signal f M Residual error and measurement noise after inter-satellite double difference Auxiliary frequency signal f A Residual error and measurement noise after inter-satellite double difference The wavelength of the secondary frequency signal. Auxiliary frequency signal f A Candidate values ​​for double-difference integer ambiguity, E Wide This refers to the bandwidth of the error band for satellite pairs i and j. Main frequency signal f M Candidate values ​​for double-difference integer ambiguity. v represents the number of candidate values; Finally, the candidate values ​​for the double-difference integer ambiguity of the main frequency signal of all satellite pairs in the single epoch data are represented as follows: Perform on the candidate values By arranging and combining groups, candidate groups of double-difference integer ambiguities of the main frequency signals of all satellite pairs in the single epoch data are obtained, where t represents the total number of candidate groups.

3. The method according to claim 1, characterized in that, For multi-frequency signals, determine the primary frequency signal and the secondary frequency signal, such that the secondary frequency signal f A Corresponding wavelength With the main frequency signal f M Corresponding wavelength The ratio Keep it as small as possible, where C is the speed of light.

4. The method according to claim 1, characterized in that, The point accuracy of the optimal solution is determined as follows: Suppose the variance matrix is ​​represented as: The accuracy of the point is: in, For the positioning accuracy of the rover station, This provides an estimate of the mean square error in the X-direction of single-epoch satellite positioning for the rover. The Y-axis mean square error estimate for single-epoch satellite positioning of the rover station. Estimated error in the Z-direction of single-epoch satellite positioning for the rover station. Estimate the covariance between the X and Y directions of the rover's single-epoch satellite positioning. Estimate the covariance between the X and Z directions of the rover's single-epoch satellite positioning. Estimate the covariance between the Y and Z directions of the single-epoch satellite positioning of the rover station.

5. The method according to claim 1, characterized in that, The point accuracy of the optimal solution is determined as follows: Suppose the variance matrix is ​​represented as: Then according to get in, B0 and L0 are the geodetic latitude and longitude of the rover's location, respectively. The accuracy of the specified point is: in, For the positioning accuracy of the rover station, Estimate the northward mean square error of single-epoch satellite positioning for the rover station. The eastward mean square error estimate for single-epoch satellite positioning of the rover station. To estimate the elevation mean square error of the single-epoch satellite positioning of the rover station. Estimate the covariance between the northward and eastward directions for single-epoch satellite positioning of the rover station. Estimate the covariance between the northward and elevation directions of the rover's single-epoch satellite positioning. This is the estimated covariance between the eastward and elevation directions of the single-epoch satellite positioning of the rover station.

6. The method according to claim 1, characterized in that, The threshold is determined as follows: in, The threshold value is... f is the wavelength corresponding to the main frequency signal of the multi-frequency signal-based satellite navigation system. M Let C be the frequency corresponding to the main frequency signal of the satellite navigation system based on multi-frequency signals, and C be the speed of light.

7. The method according to claim 1, characterized in that, For the first frequency of a satellite navigation system based on multi-frequency signals, the threshold value is taken in the range of 0.1613 to 0.1663 meters.

8. The method according to claim 1, characterized in that, For a satellite navigation system based on multi-frequency signals, the main frequency signal is the narrow-lane combined observation frequency, and the threshold is 0.092 meters.

Images