A method for real-time evaluation of low-orbit satellite real-time orbit accuracy

Abstract

The invention discloses a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite. The method comprises the following steps: obtaining a near-real-time orbit determination result of a low-orbit satellite to be evaluated under each type of orbit determination mode; determining overlapping arcs in a previous round of orbit determination results under each type of orbit determination mode and a near-real-time orbit determination result under the type of orbit determination mode, and obtaining residual overlapping arcs under the type of orbit determination mode after removing useless arcs in the overlapping arcs from the near-real-time orbit determination results; determining a near-real-time URE under the type of orbit determination mode by using the residual overlapping arcs under the type of orbit determination mode; determining a real-time URE corresponding to the type of orbit determination mode according to the near-real-time URE under the type of orbit determination mode and a change speed of a prediction accuracy of an orbit pre-calculated under the type of orbit determination mode, thereby improving the real-time orbit accuracy evaluation method for the low-orbit satellite to be evaluated and facilitating optimal selection of the real-time orbit for fitting and broadcasting.

Description

Technical Field

[0001] The invention belongs to the field of satellite positioning and timing, and in particular relates to a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite. Background Art

[0002] Thanks to the low altitude, high speed and low cost of low-orbit satellites, low-orbit enhanced GNSS (Global Navigation Satellite System) positioning, navigation and timing have a series of advantages such as strong signal strength, short convergence time, and whitening of multipath effects, and have received more and more attention in recent years. In order to better utilize low-orbit navigation signals to achieve high-precision real-time positioning and timing on the ground, the global navigation satellite system requires users to broadcast high-precision low-orbit satellite orbit products in real time, which is also the key to determining the accuracy of future low-orbit enhanced GNSS ground positioning, navigation and timing.

[0003] Since real-time orbit determination of low-orbit satellites requires time for data collection and processing, the real-time orbits of low-orbit satellites broadcast to users are all predicted orbits, that is, orbits obtained by finding a suitable forecast time period corresponding to the real-time window for orbit fitting. In actual processing, multiple forms of real-time orbit determination are often performed, such as batch dynamic orbit determination, filtered dynamic orbit determination, batch kinematic orbit determination, and filtered kinematic orbit determination. Different orbit types have different orbit determination accuracy, orbit determination product generation time, and forecast time corresponding to the real-time window, and the accuracy of the predicted orbit to be broadcast is different. When only one set of ephemeris parameters is broadcast to the user, only one orbit can be selected.

[0004] At present, when it is difficult to conduct real-time accuracy assessment of multiple forecast orbits, the best orbit product based on experience is often adopted, that is, the dynamic forecast orbit. However, this method has a single real-time accuracy assessment method and low accuracy. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite, comprising:

[0008] Obtain near-real-time orbit determination results of the low-orbit satellite to be evaluated under each type of orbit determination method;

[0009] Determine the overlapping arc segments in the previous round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and remove useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode;

[0010] The remaining overlapping arcs under each orbit determination method are used to determine the near real-time URE under that orbit determination method.

[0011] The real-time URE corresponding to each type of orbit determination method is determined according to the near real-time URE under each type of orbit determination method and the change speed of the orbit prediction accuracy pre-calculated under the type of orbit determination method.

[0012] Optionally, the pre-calculation method of the forecast accuracy change speed includes:

[0013] According to the orbital height of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; the various table files include earth rotation parameter files;

[0014] The prediction accuracy change of the orbit is calculated based on the near real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, and the prediction accuracy change speed of the predicted orbit determination result accuracy under each type of orbit determination method with the change of prediction time is obtained.

[0015] Optionally, the remaining overlapping arcs under each type of orbit determination method are used to determine the near real-time URE under the type of orbit determination method, including:

[0016] Obtain the URE of the remaining overlapping arcs under each type of orbit determination method;

[0017] For the remaining overlapping arcs under various orbit determination methods, perform the following operations: The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than The residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE; wherein, Second.

[0018] Optionally, determining a real-time URE corresponding to each type of orbit determination method according to the near real-time URE under each type of orbit determination method and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination method includes:

[0019] For each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ;

[0020] If the final predicted time under this type of orbit determination method is not less than The real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method.

[0021] Optional, for each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ,include:

[0022] ;

[0023] in, Represents a floor operation.

[0024] Optional, for each type of orbit determination method, when the last predicted time under this type of orbit determination method is not less than When the real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method, the real-time URE corresponding to the orbit determination method is determined, including:

[0025] ;

[0026] in, Indicates real-time URE; Indicates near real-time URE; Indicates the rate of change of forecast accuracy.

[0027] Optionally, the method further includes:

[0028] Various orbit determination methods are sorted according to the real-time URE, and real-time ephemeris fitting and broadcasting are performed according to preset rules.

[0029] In a second aspect, the present invention provides a device for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite, the device comprising:

[0030] An acquisition module is used to obtain near-real-time orbit determination results of the low-orbit satellite to be evaluated under each type of orbit determination mode;

[0031] The remaining overlapping arc segment determination module is used to determine the overlapping arc segments in the previous round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and remove the useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode;

[0032] A near real-time URE determination module is used to determine the near real-time URE under each type of orbit determination mode by using the remaining overlapping arc segments under the type of orbit determination mode;

[0033] The real-time URE determination module is used to determine the real-time URE corresponding to each type of orbit determination mode according to the near real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode.

[0034] Optionally, the pre-calculation method of the forecast accuracy change speed includes:

[0035] According to the orbital height of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; the various table files include earth rotation parameter files;

[0036] The prediction accuracy change of the orbit is calculated based on the near real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, and the prediction accuracy change speed of the predicted orbit determination result accuracy under each type of orbit determination method with the change of prediction time is obtained.

[0037] Optionally, the near real-time URE determination module is specifically used to obtain the URE of the remaining overlapping arc segments under each type of orbit determination mode; perform the following operations on the remaining overlapping arc segments under each type of orbit determination mode: for an arc length greater than The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than The residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE; wherein, Second.

[0038] Optional, real-time URE determination module, specifically for each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ; If the final predicted time under this type of orbit determination method is not less than The real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method.

[0039] Optional, real-time URE determination module, for each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ,include:

[0040] ;

[0041] in, Represents a floor operation.

[0042] Optional, real-time URE determination module, for each type of orbit determination method, when the last predicted time under this type of orbit determination method is not less than When the real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method, the real-time URE corresponding to the orbit determination method is determined, including:

[0043] ;

[0044] in, Indicates real-time URE; Indicates near real-time URE; Indicates the rate of change of forecast accuracy.

[0045] Optionally, the device further comprises:

[0046] The sorting module is used to sort various orbit determination methods according to the real-time URE, and perform real-time ephemeris fitting and broadcast according to preset rules.

[0047] The present invention provides a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite. The method determines the near-real-time URE under each type of orbit determination mode by using the remaining overlapping arc segments under the type of orbit determination mode. The real-time URE corresponding to the type of orbit determination mode is determined according to the near-real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode. In the process of calculating the orbit determination accuracy, the near-real-time URE under different types of orbit determination modes and the change speed of the prediction accuracy of the orbit pre-calculated are taken into account. The real-time orbit accuracy evaluation method for the low-orbit satellite to be evaluated is improved, and the real-time orbit is selected to be fitted and broadcasted.

[0048] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flowchart of a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite provided by an embodiment of the present invention;

[0050] Figure 2 It is a structural schematic diagram of a device for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0052] In order to solve the technical problem that the existing method for real-time evaluation of the real-time orbit accuracy of low-orbit satellites has a single evaluation method and low accuracy. Figure 1 , Figure 1 1 is a flow chart of a method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite provided by an embodiment of the present invention, and the specific steps are as follows:

[0053] Step S101, obtaining near real-time orbit determination results of the low-orbit satellite to be evaluated under each type of orbit determination mode.

[0054] In the embodiment of the present invention, the types of orbit determination methods include batch dynamic orbit determination, filtered dynamic orbit determination, batch kinematic orbit determination, filtered kinematic orbit determination, and the like.

[0055] In the embodiment of the present invention, the orbit determination result includes the position information, velocity information, orbit accuracy and time information of the low-orbit satellite to be evaluated. Among them, the low-orbit satellite refers to a satellite operating at a relatively low orbital altitude. The near-real-time orbit determination result means that the current orbit determination result is obtained after a certain delay. Although it is not an immediate orbit determination result, the delay is relatively small.

[0056] Step S102, determining the overlapping arc segments between the last round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and removing useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode.

[0057] In an embodiment of the present invention, after a certain type of real-time orbit determination is completed, the overlapping arc segments between the arc segments in the near-real-time orbit determination result and the arc segments in the previous round of orbit determination results are searched. The previous round of orbit determination results under each type of orbit determination method is the orbit determination result of the previous round of the near-real-time orbit determination result under this type of orbit determination method. For example, if the real-time orbit determination result is the orbit determination result of the third round, the orbit determination result of the previous round of the real-time orbit determination result is the orbit determination result of the second round.

[0058] In the embodiment of the present invention, due to the continuity and periodicity of the satellite orbit, there will be an overlapping portion between two orbit determination results, and this portion is called an overlapping arc segment.

[0059] In the embodiment of the present invention, useless arc segments are removed to avoid the influence of some instantaneous unstable noise on data analysis.

[0060] Specifically, removing useless arc segments in the overlapping arc segments from the near real-time orbit determination result may be as follows: removing the head and tail of the overlapping arc segments from the near real-time orbit determination result. seconds of arc length. For example, Seconds may preferably be 1800 seconds.

[0061] In the embodiment of the present invention, by removing useless arc segments in the overlapping arc segments, it can be ensured that the effective parts are subsequently analyzed and calculated, so that the obtained data will be more accurate.

[0062] Step S103: using the remaining overlapping arcs in each type of orbit determination mode, determine the near real-time URE in that type of orbit determination mode.

[0063] In the embodiment of the present invention, URE (User Range Error) refers to the difference between the actual orbit value of the low-orbit satellite and the predicted orbit value predicted by using the orbit determination method.

[0064] The size of URE is usually affected by many factors. In addition to atmospheric effects and multipath effects, the orbit determination algorithms used by different types of orbit determination methods will also affect URE. Therefore, it is necessary to calculate the near-real-time URE for each type of orbit determination method.

[0065] In one implementation, the remaining overlapping arc segments under each type of orbit determination method are used to determine the near real-time URE under the type of orbit determination method, including:

[0066] Obtain the URE of the remaining overlapping arcs under each type of orbit determination method;

[0067] For the remaining overlapping arcs under various orbit determination methods, perform the following operations: The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than For the remaining overlapping arc of 1.5 seconds, the residual RMS (Root Mean Square) of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE.

[0068] In the embodiment of the present invention, when the arc length of the remaining overlapping arc segments is greater than seconds, it indicates that the data volume brought by the remaining overlapping arcs is sufficient and reliable, so the URE of the remaining overlapping arcs can be directly used as the near real-time URE. seconds, it means that the amount of data brought by the remaining overlapping arcs is insufficient. In this case, a new method is needed to calculate the near-real-time URE. Specifically, the residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band can be multiplied by 10 as the near-real-time URE.

[0069] In an embodiment of the present invention, Seconds is the preset time threshold, and the specific value can be 1800 seconds.

[0070] Step S104 , determining the real-time URE corresponding to each type of orbit determination mode according to the near real-time URE under each type of orbit determination mode and the change speed of the orbit prediction accuracy pre-calculated under the type of orbit determination mode.

[0071] In the embodiment of the present invention, the change speed of the prediction accuracy of the orbit pre-calculated refers to the speed at which the accuracy of the orbit in the prediction orbit determination result changes with the prediction time. Since the accuracy of the orbit in the orbit determination result obtained by each type of orbit determination method is different, the speed at which the prediction accuracy of the orbit changes with the prediction time in each type of orbit determination method is also different.

[0072] When the near-real-time URE under each type of orbit determination method and the change rate of the prediction accuracy of the orbit under this type of orbit determination method are known, the real-time URE corresponding to this type of orbit determination method can be obtained. The real-time URE represents the difference between the actual orbit value of the low-orbit satellite and the predicted orbit value predicted by the orbit determination method in real time.

[0073] In an embodiment of the present invention, the near real-time URE under each type of orbit determination mode is determined by utilizing the remaining overlapping arc segments in the near real-time orbit determination result under the type of orbit determination mode, and the real-time URE corresponding to the type of orbit determination mode is determined according to the near real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode. In the process of calculating the orbit determination accuracy, the near real-time URE under different types of orbit determination modes and the change speed of the accuracy of the orbit pre-calculated are taken into account, and the real-time orbit accuracy assessment method for the low-orbit satellite to be assessed is improved, so as to facilitate the optimal selection of the real-time orbit for fitting and broadcasting.

[0074] In one implementation, the pre-calculation method of the forecast accuracy change rate includes:

[0075] (1) Based on the orbital altitude of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; the various table files include the Earth rotation parameter file.

[0076] (2) Based on the near-real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, the change in orbit prediction accuracy is calculated to obtain the change rate of the prediction accuracy of the predicted orbit determination result under each type of orbit determination method as the prediction time changes.

[0077] In the embodiment of the present invention, the orbital altitude refers to the altitude at which the low-orbit satellite to be evaluated is running in orbit.

[0078] In the embodiment of the present invention, the real-time GNSS product includes real-time observation data and real-time star clock ephemeris of different GNSS satellites acquired in real time by using a GNSS receiver. Various table files include earth rotation parameter files.

[0079] In the embodiment of the present invention, the orbit determination algorithm is determined according to the selected orbit determination method, and then the orbit is determined according to the real-time GNSS product and various table files.

[0080] In an embodiment of the present invention, the near real-time orbit determination result samples and the multiple predicted orbit determination result samples are orbit determination result samples in multiple continuous time periods. By fitting the orbit determination accuracy in the near real-time orbit determination result samples and the orbit determination accuracy of the multiple predicted orbit determination result samples as well as time, the slope can be obtained as the prediction accuracy change rate of the orbit prediction accuracy with the prediction time.

[0081] In one implementation, determining the real-time URE corresponding to each type of orbit determination method according to the near real-time URE under each type of orbit determination method and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination method includes:

[0082] (1) For each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ;

[0083] (2) If the final predicted time under this type of orbit determination method is not less than The real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method.

[0084] Among them, the final prediction time refers to the final moment of orbit prediction under a type of orbit determination method.

[0085] In the embodiment of the present invention, in the process of real-time accuracy evaluation of the real-time orbit of the low-orbit satellite under multiple types of orbit determination modes, the near-real-time orbit determination results and the corresponding real-time ephemeris fitting time period are taken into account, and the optimization strategy of the real-time orbit is improved.

[0086] In the embodiment of the present invention, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ,include:

[0087] ;

[0088] in, Represents a floor operation.

[0089] In addition, if the final prediction time of a certain type of orbit determination method is less than , it means that the arc segment of the predicted orbit under this type of orbit determination method cannot cover the real-time ephemeris fitting time period, that is, the orbit prediction time length of this type of orbit determination method is insufficient.

[0090] In one implementation, for each type of orbit determination method, when the last predicted time under this type of orbit determination method is not less than When the real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method, the real-time URE corresponding to the orbit determination method is determined, including:

[0091] ;

[0092] in, Indicates real-time URE; Indicates near real-time URE; Indicates the rate of change of forecast accuracy.

[0093] In one implementation, the method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite provided by an embodiment of the present invention may further include:

[0094] Various orbit determination methods are sorted according to the real-time URE, and real-time ephemeris fitting and broadcasting are performed according to preset rules.

[0095] In the embodiment of the present invention, the real-time URE represents the difference between the real orbit value of the low-orbit satellite and the predicted orbit value obtained by real-time orbit determination. Therefore, the smaller the real-time URE is, the higher the real-time orbit accuracy of the orbit determination method is, and the higher the real-time orbit accuracy of the low-orbit satellite is. Conversely, the larger the real-time URE is, the lower the real-time orbit accuracy of the orbit determination method is, and the lower the real-time orbit accuracy of the low-orbit satellite is.

[0096] In addition, for the orbit determination methods that have not calculated the real-time URE, after the orbit determination methods that have calculated the real-time URE are sorted, the orbit determination methods that have not calculated the real-time URE are sorted after the orbit determination methods that have calculated the real-time URE in a predetermined order.

[0097] In the embodiment of the present invention, various orbit determination methods are sorted according to the real-time URE, and the specific method of performing real-time ephemeris fitting and broadcasting according to the preset rules is as follows:

[0098] After sorting various orbit determination methods from small to large according to real-time URE, the orbit determination method with a smaller real-time URE is given priority for real-time ephemeris fitting and broadcasting, the orbit determination method with the second smallest real-time URE is given second priority for real-time ephemeris fitting and broadcasting, and so on. This method can improve the accuracy of real-time orbits, allowing users to choose the most appropriate solution in different situations.

[0099] It should be noted that in certain situations, such as orbital maneuvers or when onboard GNSS observations are unavailable, a specific orbit type will be forced to take the first priority regardless of the real-time URE size to ensure that the correct orbit type is selected in the specific situation, thereby ensuring orbit accuracy.

[0100] In the embodiment of the present invention, various orbit determination methods are sorted according to the real-time URE, which makes it easier to perform optimal fitting and broadcasting of orbit determination results.

[0101] Based on the same inventive concept, the embodiment of the present invention also provides a device for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite, see Figure 2 , Figure 2 1 is a schematic diagram of a structure of a device for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite provided by an embodiment of the present invention, the device comprising:

[0102] An acquisition module 201 is used to obtain near real-time orbit determination results of the low-orbit satellite to be evaluated in each type of orbit determination mode;

[0103] The remaining overlapping arc segment determination module 202 is used to determine the overlapping arc segments in the previous round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and remove the useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode;

[0104] A near real-time URE determination module 203 is used to determine the near real-time URE under each type of orbit determination mode by using the remaining overlapping arc segments under the type of orbit determination mode;

[0105] The real-time URE determination module 204 is used to determine the real-time URE corresponding to each type of orbit determination mode according to the near real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode.

[0106] In an embodiment of the present invention, the near real-time URE under each type of orbit determination mode is determined by utilizing the remaining overlapping arc segments under the type of orbit determination mode, and the real-time URE corresponding to the type of orbit determination mode is determined according to the near real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode. In the process of calculating the orbit determination accuracy, the near real-time URE under different types of orbit determination modes and the change speed of the prediction accuracy of the orbit pre-calculated are taken into account, and the real-time orbit accuracy assessment method for the low-orbit satellite to be assessed is improved, so as to facilitate the optimal selection of the real-time orbit for fitting and broadcasting.

[0107] Optionally, the pre-calculation method of the forecast accuracy change rate includes:

[0108] According to the orbital height of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; various table files include earth rotation parameter files;

[0109] The prediction accuracy change of the orbit is calculated based on the near real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, and the prediction accuracy change speed of the predicted orbit determination result accuracy under each type of orbit determination method with the change of prediction time is obtained.

[0110] Optional, near real-time URE determination module, specifically used to obtain the URE of the remaining overlapping arc segments under each type of orbit determination method; perform the following operations on the remaining overlapping arc segments under each type of orbit determination method: for arc length greater than The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than For the remaining overlap arc of 10 seconds, the residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE; where Second.

[0111] Optional, real-time URE determination module, specifically for each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ; If the final predicted time under this type of orbit determination method is not less than The real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method.

[0112] Optional, real-time URE determination module, for each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ,include:

[0113] ;

[0114] in, Represents a floor operation.

[0115] Optional, real-time URE determination module, for each type of orbit determination method, when the last predicted time under this type of orbit determination method is not less than When the real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method, the real-time URE corresponding to the orbit determination method is determined, including:

[0116] ;

[0117] in, Indicates real-time URE; Indicates near real-time URE; Indicates the rate of change of forecast accuracy.

[0118] Optionally, the device further comprises:

[0119] The sorting module is used to sort various orbit determination methods according to the real-time URE, and perform real-time ephemeris fitting and broadcast according to preset rules.

[0120] It should be noted that the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention.

[0121] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0122] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other changes to the disclosed embodiments by viewing the drawings and the disclosed content. In the description of the present invention, the term "comprising" does not exclude other components or steps, "one" or "an" does not exclude multiple situations, and "multiple" means two or more, unless otherwise clearly and specifically limited. In addition, certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0123] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0124] It should be noted that the device of an embodiment of the present invention is a device that applies the above-mentioned method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite. All embodiments of the above-mentioned method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite are applicable to the device and can achieve the same or similar beneficial effects.

[0125] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite, characterized in that: The method comprises: Obtain near-real-time orbit determination results of the low-orbit satellite to be evaluated under each type of orbit determination method; Determine the overlapping arc segments in the previous round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and remove useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode; The remaining overlapping arcs under each orbit determination method are used to determine the near real-time URE under that orbit determination method. Determine the real-time URE corresponding to each type of orbit determination method according to the near real-time URE under each type of orbit determination method and the change rate of the orbit prediction accuracy pre-calculated under the type of orbit determination method; Determining the near real-time URE under each type of orbit determination mode by using the remaining overlapping arc segments under the type of orbit determination mode includes: Obtain the URE of the remaining overlapping arcs under each type of orbit determination method; For the remaining overlapping arcs under various orbit determination methods, perform the following operations: The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than The residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE; wherein, Second.

2. The method according to claim 1, characterized in that The pre-calculation method of the forecast accuracy change speed includes: According to the orbital height of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; the various table files include earth rotation parameter files; The prediction accuracy change of the orbit is calculated based on the near real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, and the prediction accuracy change speed of the predicted orbit determination result accuracy under each type of orbit determination method with the change of prediction time is obtained.

3. The method according to claim 1, characterized in that The real-time URE corresponding to each type of orbit determination method is determined according to the near real-time URE under each type of orbit determination method and the change rate of the orbit prediction accuracy pre-calculated under the type of orbit determination method, including: For each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ; If the final predicted time under this type of orbit determination method is not less than The real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method.

4. The method according to claim 3, characterized in that For each type of orbit determination method, according to the current time Fitting time with real-time ephemeris Calculate the midpoint of the real-time ephemeris fitting period ,include: ； in, Represents a floor operation.

5. The method according to claim 3, characterized in that: For each type of orbit determination method, when the last predicted time under this type of orbit determination method is not less than When the real-time URE corresponding to the orbit determination method is determined according to the near real-time URE under the orbit determination method and the change rate of the prediction accuracy of the orbit pre-calculated under the orbit determination method, the real-time URE corresponding to the orbit determination method is determined, including: ； in, Indicates real-time URE; Indicates near real-time URE; Indicates the rate of change of forecast accuracy.

6. The method according to claim 1, characterized in that The method further comprises: Various orbit determination methods are sorted according to the real-time URE, and real-time ephemeris fitting and broadcasting are performed according to preset rules.

7. A device for real-time evaluation of the real-time orbit accuracy of a low-orbit satellite, characterized in that: The device comprises: An acquisition module is used to obtain near-real-time orbit determination results of the low-orbit satellite to be evaluated under each type of orbit determination mode; The remaining overlapping arc segment determination module is used to determine the overlapping arc segments in the previous round of orbit determination results under each type of orbit determination mode and the near real-time orbit determination results under this type of orbit determination mode, and remove the useless arc segments in the overlapping arc segments from the near real-time orbit determination results to obtain the remaining overlapping arc segments under this type of orbit determination mode; A near real-time URE determination module is used to determine the near real-time URE under each type of orbit determination mode by using the remaining overlapping arc segments under the type of orbit determination mode; A real-time URE determination module is used to determine the real-time URE corresponding to each type of orbit determination mode according to the near real-time URE under each type of orbit determination mode and the change speed of the prediction accuracy of the orbit pre-calculated under the type of orbit determination mode; The near real-time URE determination module is specifically used to: Obtain the URE of the remaining overlapping arc segments under each type of orbit determination method; perform the following operations on the remaining overlapping arc segments under each type of orbit determination method: The remaining overlapping arc segment of 10 seconds is selected as the near-real-time URE; for the arc segment with a length of no more than The residual RMS of the carrier phase observation of the low-orbit satellite to be evaluated converted to the L1 frequency band is multiplied by 10 as the near-real-time URE; wherein, Second.

8. The device according to claim 7, characterized in that The pre-calculation method of the forecast accuracy change speed includes: According to the orbital height of the low-orbit satellite to be evaluated and each type of orbit determination method, batch orbit determination calculations are performed using real-time GNSS products and various table files to obtain near-real-time orbit determination result samples and multiple predicted orbit determination result samples under this type of orbit determination method; the various table files include earth rotation parameter files; The prediction accuracy change of the orbit is calculated based on the near real-time orbit determination result samples and multiple predicted orbit determination result samples under each type of orbit determination method, and the prediction accuracy change speed of the predicted orbit determination result accuracy under each type of orbit determination method with the change of prediction time is obtained.

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