K-band intersatellite rangefinder data quality assessment method and system

Abstract

The present invention discloses a K-band intersatellite rangefinder data quality assessment method and system, relating to the fields of geodesy and space science and technology. The method comprises obtaining a sequence of ionospheric residual combined observations based on K-band observations measured by the K-band intersatellite rangefinder corresponding to a low-low tracking gravity satellite at each epoch, Ka-band observations measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; and performing a quality assessment of the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite based on the ionospheric residual combined observation sequence. The present invention not only enables assessment using only a single satellite, without requiring dual-satellite time synchronization, thereby improving the accuracy of the assessment results, but also allows direct assessment of the KBR data quality of a single satellite.

Description

Technical Field

[0001] The present invention relates to the field of geodesy and space science and technology, and in particular to a method and system for evaluating the data quality of a K-band intersatellite rangefinder. Background Art

[0002] The satellite gravity measurement system mainly uses high-orbit satellites tracking low-orbit satellites (high-low tracking), low-orbit satellites tracking low-orbit satellites (low-low tracking), satellite gravity gradients and other methods to detect the Earth's gravity field. Among them, the GRACE / GRACE Follow-On satellites use a combination of high-low tracking and low-low tracking (referred to as low-low tracking gravity satellites) to detect the Earth's gravity field. The three core payloads of the low-low tracking gravity satellite are the K-band ranging instrument (KBR), the electrostatically suspended accelerometer (ACC) and the GNSS receiver. The KBR rangefinder is used to observe the relative distance between two satellites and its rate of change with micron-level accuracy, the high-precision electrostatically suspended accelerometer is used to observe the non-conservative force on the satellite's center of mass, and the dual-frequency GNSS receiver is used to determine the satellite's precise orbit and time synchronization, thereby inverting the Earth's gravity field.

[0003] Since the K-band intersatellite rangefinder of low-low tracking gravity satellites is very accurate, the distance between the two satellites is about 170 to 270 km, and there is a lack of external high-precision comparison benchmarks, it is difficult to directly evaluate the data quality and accuracy. It is often evaluated by the accuracy of the inverted gravity field model product or by the post-validation residual, which lacks direct evaluation methods. For KBR data quality assessment, a double difference combination method based on the K and Ka band observations of the two satellites is usually used. Specifically, taking the K frequency phase observations of the KBR intersatellite rangefinders of satellites A and B as an example, the KBR1A-level raw observation data can be expressed as follows

[0004]

[0005] in, is the phase measurement value of satellite A, i.e., the KBR intersatellite rangefinder k-band observation value corresponding to satellite A. is the phase measurement value of satellite B, i.e., the KBR intersatellite rangefinder k-band observation value corresponding to satellite B, t is the nominal receiving time, i.e., the epoch of the received data, Δt A , Δt B is the clock error of satellites A and B, ρ(t+Δt A ) is the geometric distance between the binary stars (independent of frequency), is the integer ambiguity of the K-band observations of the KBR intersatellite rangefinders of satellites A and B, is the ionospheric delay of the KBR intersatellite rangefinder k-band observation of satellites A and B, W is the phase winding value, is the number of truncation times of the phase entanglement of the K frequency points of the two satellites A and B, is the multipath delay and other residual errors of the K-band observations of the KBR intersatellite rangefinder of satellites A and B.

[0006] To evaluate the KBR1A data quality, we usually use the double difference combination of the binary K observation and Ka observation to remove all kinds of errors, leaving only the observation noise, and then evaluate the KBR data quality. The expression is as follows

[0007]

[0008] Where, is the double-difference observation quantity of the binary star, are the K frequency of star A, the K frequency of star B, the Ka frequency of star A and the Ka frequency of star B, ΔN is the combined ambiguity, is the combined noise. As can be seen from the above equation, ignoring the flight time corrections and frequency ratio differences between the two satellites, the ionosphere between the two satellites is consistent. That is, the first term in the equation can be discarded, leaving only the ambiguity and combined noise. Therefore, it can be used to assess the quality of dual-satellite KBR data. However, this method requires the time-scale alignment of the two satellite observations, so the combined noise will include dual-satellite time synchronization errors. Furthermore, it only provides the noise characteristics of the dual-satellite KBR observations and cannot be used to assess the quality of individual satellite KBR data. This method has two major drawbacks: First, it requires strict time synchronization (alignment) between the two satellites, otherwise it introduces dual-satellite time synchronization errors, resulting in inaccurate KBR data quality assessments and a relatively complex processing method. Second, it only provides an overall assessment of dual-satellite KBR data and cannot analyze the quality of individual satellite KBR data. This is because the distance (rate of change) between the two satellites is a critical observation for low-to-low tracking gravity satellites and is used in the subsequent inversion of Earth's gravity field models. Therefore, data quality can affect model accuracy. On the other hand, the inter-satellite distance (rate of change) and satellite orbit data need to be jointly solved. Therefore, the data quality assessment results can provide a reference for the weight setting of the two observation quantities. Therefore, a method to improve the accuracy of the assessment results is needed to serve as a reference for subsequent steps. Summary of the Invention

[0009] The purpose of the present invention is to provide a K-band intersatellite rangefinder data quality assessment method and system, which can not only use only a single satellite for assessment without the need for dual-satellite time synchronization, but also improve the accuracy of the assessment results, and can directly assess the KBR data quality of a single satellite.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] A K-band intersatellite rangefinder data quality assessment method, comprising:

[0012] For any low-low tracking gravity satellite, obtaining, at each epoch within a set time period, a K-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a Ka-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite;

[0013] Obtaining a sequence of ionospheric residual combined observation quantities according to the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite;

[0014] Quality assessment is performed on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence.

[0015] Optionally, obtaining an ionospheric residual combined observation quantity sequence according to a K-band observation quantity measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, a Ka-band observation quantity measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, specifically includes:

[0016] For any epoch within the set time period, obtaining a geometric combination observation value of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite;

[0017] For any two adjacent epochs within the set time period, calculating the difference between the geometric combination observations of the K-band intersatellite range finder corresponding to the low-low tracking gravity satellite in the two adjacent epochs to obtain the ionospheric residual combination observations corresponding to the adjacent epochs;

[0018] Determine the ionospheric residual combined observation quantities corresponding to all adjacent epochs within the set time period to form an ionospheric residual combined observation quantity sequence.

[0019] Optionally, for any epoch within the set time period, obtaining a geometric combination observation value of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch according to the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, specifically includes:

[0020] According to the formula Calculate the geometric combination observation quantity of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch, where, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

[0021] Optionally, performing quality assessment on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence specifically includes:

[0022] Calculating the mean, mean square error and mean square error of the ionospheric residual combination observation sequence;

[0023] Quality assessment is performed on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the mean, the mean error and the mean square error.

[0024] A K-band intersatellite rangefinder data quality assessment system, comprising:

[0025] an acquisition module, configured to acquire, for any low-low tracking gravity satellite, a K-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a Ka-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period;

[0026] an ionospheric residual combined observation quantity sequence calculation module, configured to obtain an ionospheric residual combined observation quantity sequence based on the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite;

[0027] A quality assessment module is used to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation quantity sequence.

[0028] Optionally, the ionospheric residual combined observation quantity sequence calculation module specifically includes:

[0029] a geometric combination observation calculation unit, configured to obtain, for any epoch within the set time period, a geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite;

[0030] an ionospheric residual combined observation calculation unit, configured to calculate, for any two adjacent epochs within the set time period, a difference between geometric combined observations of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the two adjacent epochs, to obtain the ionospheric residual combined observations corresponding to the adjacent epochs;

[0031] The ionospheric residual combination observation quantity sequence determination unit is used to determine the ionospheric residual combination observation quantities corresponding to all adjacent epochs within the set time period to form an ionospheric residual combination observation quantity sequence.

[0032] Optionally, the geometric combination observation quantity calculation unit specifically includes:

[0033] The geometric combination observation calculation subunit is used to calculate the geometric combination observation quantity according to the formula Calculate the geometric combination observation quantity of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch, where, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

[0034] Optionally, the quality assessment module specifically includes:

[0035] A sequence parameter calculation unit, used to calculate the mean, mean square error and mean square error of the ionospheric residual combination observation sequence;

[0036] A quality assessment unit is used to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the mean, the mean error and the mean square error.

[0037] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the single-satellite KBR data evaluation method based on the ionospheric residual combination method of the present invention can not only use the KBR data of a single satellite, but also does not require dual-satellite time synchronization and can directly evaluate the quality of the KBR data of a single satellite, and the processing method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a flow chart of a method for evaluating K-band intersatellite rangefinder data quality provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a K-band intersatellite rangefinder data quality assessment method, comprising:

[0043] For any low-low tracking gravity satellite, obtain the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period.

[0044] An ionospheric residual combined observation sequence is obtained according to the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite.

[0045] Quality assessment is performed on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence.

[0046] In practical applications, the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite and the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period are obtained, specifically:

[0047] Step 1: Reading single star data.

[0048] The KBR 1A level data of the low-low tracking gravity satellite is read to extract K-band observation quantities and Ka-band observation quantities.

[0049] Step 2: Detect and mark various anomalies such as gross errors and cycle slips.

[0050] Gross errors, cycle slips, and phase wrapping are detected and marked for the K-band and Ka-band observations. Because these anomalies are inevitable, they must be addressed before data quality assessment to prevent them from affecting the evaluation.

[0051] 1) For gross errors, a detection and elimination processing strategy is adopted. The empirical threshold method or median filtering method can be used to detect gross errors, and then the outliers are marked and eliminated, and the eliminated data are subsequently interpolated and filled.

[0052] 2) A detection and marking strategy is adopted for cycle slips. The detected cycle slips are only marked, and the data segments where the cycle slips occur are subsequently evaluated in segments.

[0053] 3) Mark the data anomalies caused by phase wrapping, then add the phase wrapping value to restore data continuity.

[0054] Step 3: Interpolation and completion of missing and abnormal data.

[0055] After eliminating the gross errors detected in the previous step, linear interpolation or low-order polynomial interpolation is used to fill in the missing data. For cases where the original observation data is missing, short-term data gaps are filled using low-order polynomial interpolation. For long-term data gaps, interpolation is not recommended. Instead, a data segmentation strategy is used to evaluate the data quality of the previous and next data segments separately to avoid additional errors introduced by interpolation.

[0056] In practical applications, an ionospheric residual combined observation quantity sequence is obtained according to the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, specifically including:

[0057] For any epoch within the set time period, a geometric combination observation value of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the epoch is obtained according to the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the epoch, the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the epoch, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite.

[0058] For any two adjacent epochs within the set time period, the difference between the geometric combination observations of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the two adjacent epochs is calculated to obtain the ionospheric residual combination observations corresponding to the adjacent epochs.

[0059] Determine the ionospheric residual combined observation quantities corresponding to all adjacent epochs within the set time period to form an ionospheric residual combined observation quantity sequence.

[0060] Because the geometric paths of K-band observations and Ka-band observations are the same, only the frequencies are different. Therefore, the geometric combination-free observations are calculated by taking the difference between K-band and Ka-band observations and considering the frequency difference. Therefore, in practical applications,

[0061] according to

[0062]

[0063] Calculate the geometric combination observation quantity of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch, where, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

[0064] The single-satellite dual-frequency ionospheric residual combination method proposed in the present invention only uses the single-satellite dual-frequency K observation and Ka observation for difference, eliminating the geometric information in the K and Ka observations to obtain the geometry-free combination observation. The geometry-free combination observation eliminates the geometric distance between satellites, leaving only the influence of the space ionospheric delay error. Since the space ionospheric environment changes slowly in a short period of time, the influence of the ionospheric delay error can be effectively weakened by the difference between the previous and next epochs. Therefore, based on the geometry-free combination observation constructed in the previous step, the ionospheric residual combination observation is constructed. Based on

[0065]

[0066] Calculate the ionospheric residual combined observation quantity, where n and n-1 represent two adjacent epochs, represents the ionospheric residual, which can be ignored because the ionospheric delay changes very little in a short period of time. ΔN is the integer ambiguity between epochs, which is zero when no cycle slip occurs and has no effect on the observation noise assessment. is the ionospheric residual combined noise of satellite A, which can be used to evaluate the quality of KBR data of satellite A.

[0067] In practical applications, the quality assessment of the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite is performed based on the ionospheric residual combined observation sequence, specifically including:

[0068] Calculate the mean, mean square error and root mean square error of the ionospheric residual combination observation sequence.

[0069] The quality of the K-band intersatellite rangefinder data (KBR1A-level data) corresponding to the low-low tracking gravity satellite is evaluated based on the mean, mean error, and mean square error. Because the K-band intersatellite rangefinder is a core payload of the satellite, specific accuracy indicators for the rangefinder are provided during satellite design. Therefore, the data quality can be evaluated by comparing the statistical results with the design indicators.

[0070] An embodiment of the present invention further provides a K-band intersatellite rangefinder data quality assessment system corresponding to the above method, comprising:

[0071] An acquisition module is configured to acquire, for any low-low tracking gravity satellite, a K-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period.

[0072] The ionospheric residual combination observation quantity sequence calculation module is used to obtain the ionospheric residual combination observation quantity sequence according to the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite.

[0073] A quality assessment module is used to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation quantity sequence.

[0074] In practical applications, the ionospheric residual combined observation quantity sequence calculation module specifically includes:

[0075] a geometric combination observation calculation unit, configured to obtain, for any epoch within the set time period, a geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite.

[0076] The ionospheric residual combination observation calculation unit is used to calculate the difference between the geometric combination observations of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the two adjacent epochs for any two adjacent epochs within the set time period to obtain the ionospheric residual combination observations corresponding to the adjacent epochs.

[0077] The ionospheric residual combination observation quantity sequence determination unit is used to determine the ionospheric residual combination observation quantities corresponding to all adjacent epochs within the set time period to form an ionospheric residual combination observation quantity sequence.

[0078] In practical applications, the geometric combination observation quantity calculation unit specifically includes:

[0079] The geometric combination observation calculation subunit is used to calculate the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch according to formula (3), wherein, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

[0080] In practical applications, the quality assessment module specifically includes:

[0081] The sequence parameter calculation unit is used to calculate the mean, mean square error and mean square error of the ionospheric residual combination observation sequence.

[0082] A quality assessment unit is used to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the mean, the mean error and the mean square error.

[0083] This paper proposes a K-band intersatellite rangefinder (IBR) data quality assessment method for low-gravity tracking satellites. This single-satellite KBR data assessment method, based on the ionospheric residual combination method, addresses the problem of single-satellite KBR data quality assessment. This method overcomes the shortcomings of traditional methods. First, it uses only KBR data from a single satellite, eliminating the need for dual-satellite time synchronization and avoiding the introduction of time synchronization errors when combining dual-satellite KBR data. Second, it can independently assess the KBR data quality of a single satellite, simplifying the processing method.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0085] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A K-band intersatellite rangefinder data quality assessment method, characterized in that: include: For any low-low tracking gravity satellite, obtaining, at each epoch within a set time period, a K-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a Ka-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; Obtaining an ionospheric residual combined observation quantity sequence according to the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; specifically comprising: For any epoch within the set time period, obtaining a geometric combination observation value of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; For any two adjacent epochs within the set time period, calculating the difference between the geometric combination observations of the K-band intersatellite range finder corresponding to the low-low tracking gravity satellite in the two adjacent epochs to obtain the ionospheric residual combination observations corresponding to the adjacent epochs; Determining that the ionospheric residual combined observation quantities corresponding to all adjacent epochs within the set time period constitute an ionospheric residual combined observation quantity sequence; Quality assessment is performed on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence.

2. The K-band intersatellite rangefinder data quality assessment method according to claim 1, wherein: For any epoch within the set time period, obtaining a geometric combination observation value of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, specifically includes: According to the formula Calculate the geometric combination observation quantity of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch, where, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

3. The K-band intersatellite rangefinder data quality assessment method according to claim 1, wherein: Performing a quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence, specifically comprising: Calculating the mean, mean square error and mean square error of the ionospheric residual combination observation sequence; Quality assessment is performed on K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the mean, the mean error and the mean square error.

4. A K-band intersatellite rangefinder data quality assessment system, characterized in that: include: an acquisition module, configured to acquire, for any low-low tracking gravity satellite, a K-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a Ka-band observation value measured by a K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period; an ionospheric residual combined observation quantity sequence calculation module, configured to obtain an ionospheric residual combined observation quantity sequence based on the K-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at each epoch within a set time period, the Ka-band observation quantity measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, the clock error of the low-low tracking gravity satellite, the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; a quality assessment module, configured to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the ionospheric residual combined observation sequence; The ionospheric residual combination observation quantity sequence calculation module specifically includes: a geometric combination observation calculation unit, configured to obtain, for any epoch within the set time period, a geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch based on a K-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a Ka-band observation measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the epoch, a clock error of the low-low tracking gravity satellite, a K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite, and a Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite; an ionospheric residual combined observation calculation unit, configured to calculate, for any two adjacent epochs within the set time period, a difference between geometric combined observations of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite in the two adjacent epochs, to obtain the ionospheric residual combined observations corresponding to the adjacent epochs; The ionospheric residual combination observation quantity sequence determination unit is used to determine the ionospheric residual combination observation quantities corresponding to all adjacent epochs within the set time period to form an ionospheric residual combination observation quantity sequence.

5. The K-band intersatellite rangefinder data quality assessment system according to claim 4, characterized in that: The geometric combination observation quantity calculation unit specifically includes: The geometric combination observation calculation subunit is used to calculate the geometric combination observation quantity according to the formula Calculate the geometric combination observation quantity of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite at the nth epoch, where, represents the geometric combination observation of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the K-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, t represents the nominal receiving time, Δt A represents the clock error of the low-low tracking gravity satellite A at the nth epoch, represents the K frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, represents the Ka frequency of the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch, It represents the Ka-band observation value measured by the K-band intersatellite rangefinder corresponding to the low-low tracking gravity satellite A at the nth epoch.

6. The K-band intersatellite rangefinder data quality assessment system according to claim 4, characterized in that: The quality assessment module specifically includes: A sequence parameter calculation unit, used to calculate the mean, mean error and mean square error of the ionospheric residual combination observation sequence; A quality assessment unit is used to perform quality assessment on the K-band intersatellite rangefinder data corresponding to the low-low tracking gravity satellite according to the mean, the mean error and the mean square error.

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