Precise point positioning method, system and device under limited satellite communication resources, medium and product

Abstract

The invention discloses a precise point positioning method, system and device under limited satellite communication resources, a medium and a product, and relates to the field of advanced precise positioning of satellite navigation, the method comprises the following steps: receiving user data and a precise satellite correction product in real time at a system end, generating correction data matched with a user end positioning model, carrying out lightweight coding on the precision satellite correction product, and broadcasting to a user side; at a user side, analyzing a lightweight coded precise satellite correction product, determining ultra-wide lane comprehensive deviation correction information, determining a fixed EWL integer ambiguity, and determining a fixed WL integer ambiguity in combination with a wide lane integer ambiguity fixing model; in combination with a narrow lane integer ambiguity fixed model, determining a user position under a narrow lane fixed solution and updating the current user position; the PRN number of the current user visible satellite and the updated user position are sent to the system end, precise point positioning is completed, the convergence time is shortened, and the positioning precision is improved.

Description

Technical Field

[0001] This application relates to the field of advanced precision positioning in satellite navigation, and in particular to a method, system, device, medium, and product for precise point positioning under conditions of limited satellite communication resources. Background Technology

[0002] Precise point positioning (PPP) is the preferred method for providing absolutely high-precision positioning services at sea. This technology is widely used to provide decimeter-level or even centimeter-level high-precision positioning benchmarks for scenarios such as ship dynamic positioning systems and marine resource exploration and development. PPP services for the ocean rely on precise satellite correction products broadcast via communication satellite links, containing correction information for precise satellite orbits, clock biases, and deviations. However, precise satellite correction products broadcast by commercial companies such as Fugro (Netherlands) and Trimble (USA) mostly use the Inmarsat maritime satellite and Iridium low-Earth orbit satellite communication systems, resulting in relatively high communication costs. Other low-cost communication methods with full ocean coverage typically suffer from narrow communication bandwidth and broadcast frequency of only a few minutes, making it difficult to broadcast precise satellite orbit, clock bias, and deviation correction information to marine users in real time. Therefore, it is necessary to conduct research on precise point positioning methods for marine users under conditions of limited satellite communication resources.

[0003] Lightweight coding for real-time precision satellite correction products is fundamental to achieving high-precision PPP positioning services under resource-constrained conditions, including in the open ocean and polar regions. Lightweight coding for precision satellite orbit and clock error correction can be categorized into two types: compressed coding and equivalent distance coding.

[0004] Compression coding typically removes unnecessary information, reducing the number of bits required for independent precise satellite orbit and clock correction data, and does not require user location information, enabling service to a wide area with multiple users. However, to overcome the limitation of narrow communication bandwidth due to limited satellite communication resources, this method usually adopts a single-device time-division broadcasting or multi-device parallel broadcasting mode. The former increases the age of the precise satellite orbit and clock correction information, resulting in a decrease in positioning accuracy, while the latter increases the service cost. Equivalent distance coding derives the equivalent distance correction between the satellite and the station based on real-time precise satellite orbit and clock correction data and the user's approximate location; this is known as Observation Space Representation (OSR).

[0005] The number of bits required for precise satellite orbit and clock error correction information encoded with equivalent distance is much smaller than that required for precise satellite clock and orbit correction in the standard RTCM-SSR format. However, the above methods all employ a dual-frequency ionosphere-free combined PPP model. On the one hand, the dual-frequency ionosphere-free combined PPP model based on floating-point solutions requires tens of minutes of convergence time to achieve positioning accuracy at the decimeter or even centimeter level. On the other hand, combining dual-frequency ambiguity-fixed PPP with precise satellite-end fractional deviation correction information can further improve the convergence time, but the initial ambiguity fixation still requires tens of minutes. Moreover, as the age of the precise satellite correction product increases, the time for the initial ambiguity fixation also increases, limiting the real-time application of precise single-point positioning under conditions of limited satellite communication resources. Summary of the Invention

[0006] The purpose of this application is to provide a method, system, device, medium, and product for precise point positioning under limited satellite communication resources, so as to solve the problem of slow convergence time and low positioning accuracy caused by minute-level precise satellite orbit and clock error correction accuracy in traditional precise point positioning under limited satellite communication resources.

[0007] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a precise point positioning method under conditions of limited satellite communication resources, including: On the system side, user data and precision satellite correction products are received in real time; the user data includes user location information and the PRN number of the satellite visible to the user; the precision satellite correction products include correction information for precision satellite orbit, clock error, phase deviation and code deviation; At the system end, correction data matching the user-end positioning model is generated based on the user data and the precision satellite correction product; the correction data includes precision satellite orbit and clock error equivalent correction based on OSR format, satellite end ultra-wide lane comprehensive deviation correction, satellite end wide lane comprehensive deviation correction, and satellite end narrow lane comprehensive deviation correction. At the system end, combining the correction data and the bandwidth requirements under limited satellite communication resources, the precision satellite correction product is lightweight-coded according to the PRN number of the user-visible satellite and broadcast to the user end; At the user end, based on the real-time received satellite observations and broadcast ephemeris messages, the lightweight coded precision satellite correction product is analyzed to determine the ultra-wide lane comprehensive deviation correction information, and a fixed EWL integer ambiguity is determined based on the ultra-wide lane comprehensive deviation correction information. At the user end, a fixed WL integer ambiguity is determined based on the fixed EWL integer ambiguity, real-time OSR-based precise satellite orbit and clock bias equivalent correction, a wide-lane integer ambiguity fixed model, and a satellite-end wide-lane comprehensive deviation correction matching the wide-lane integer ambiguity fixed model; the wide-lane integer ambiguity fixed model is a wide-lane integer ambiguity model based on inter-satellite differential multi-frequency geometric correlation ionosphere-free combination. Based on the fixed EWL integer ambiguity, the fixed WL integer ambiguity, real-time OSR-based precise satellite orbit and clock error equivalent correction, the narrow-lane integer ambiguity fixed model, and the satellite-end narrow-lane comprehensive deviation correction matched with the narrow-lane integer ambiguity fixed model, the user position under the narrow-lane fixed solution is determined and the current user position is updated; the narrow-lane integer ambiguity fixed model is an ionosphere-free narrow-lane integer ambiguity model based on inter-satellite differences. The system sends the current visible satellite PRN number and the updated user location to the system terminal to complete precise single-point positioning.

[0008] Secondly, this application provides a precise point positioning system under conditions of limited satellite communication resources, comprising: The data receiving module is used to receive user data and precision satellite correction products in real time at the system end; the user data includes user location information and the PRN number of the satellite visible to the user; the precision satellite correction products include correction information for precision satellite orbit, clock error, phase deviation and code deviation; The correction data generation module is used to generate correction data that matches the user-end positioning model based on the user data and the precision satellite correction product at the system end; the correction data includes precision satellite orbit and clock error equivalent correction based on OSR format, satellite-end ultra-wide lane comprehensive deviation correction, satellite-end wide lane comprehensive deviation correction, and satellite-end narrow lane comprehensive deviation correction. The lightweight encoding module is used at the system end to perform lightweight encoding of the precision satellite correction product based on the user-visible satellite PRN number, taking into account the correction data and the bandwidth requirements under limited satellite communication resources, and then broadcasting it to the user end. A fixed EWL integer ambiguity determination module is used at the user end to parse the lightweight coded precision satellite correction product based on the real-time received satellite observations and broadcast ephemeris messages, determine the ultra-wide lane comprehensive deviation correction information, and determine the fixed EWL integer ambiguity based on the ultra-wide lane comprehensive deviation correction information. A fixed WL integer ambiguity determination module is used at the user end to determine a fixed WL integer ambiguity based on the fixed EWL integer ambiguity, real-time OSR-based precise satellite orbit and clock bias equivalent correction, a wide-lane integer ambiguity fixed model, and a satellite-end wide-lane comprehensive deviation correction matching the wide-lane integer ambiguity fixed model; the wide-lane integer ambiguity fixed model is a wide-lane integer ambiguity model based on inter-satellite differential multi-frequency geometric correlation ionosphere-free combination. The user location update module is used to determine the user's location under the narrow-lane fixed solution based on the fixed EWL integer ambiguity, the fixed WL integer ambiguity, real-time precise satellite orbit and clock error equivalent correction based on OSR format, the narrow-lane integer ambiguity fixed model, and the satellite-end narrow-lane comprehensive deviation correction matched with the narrow-lane integer ambiguity fixed model, and update the current user's location; the narrow-lane integer ambiguity fixed model is an ionosphere-free narrow-lane integer ambiguity model based on inter-satellite difference. The precise point positioning module is used to send the current visible satellite PRN number and the updated user location to the system to complete precise point positioning.

[0009] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described precise single-point positioning method under limited satellite communication resources.

[0010] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the aforementioned precise point positioning method under satellite communication resource constraints.

[0011] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned precise single-point positioning method under satellite communication resource constraints.

[0012] This application has the following technical advantages: 1) On the system side, construct precise satellite orbit and clock error equivalent corrections, satellite-side ultra-wide lane comprehensive deviation corrections, satellite-side wide lane comprehensive deviation corrections, and satellite-side narrow lane comprehensive deviation corrections based on the Observation Space Representation (OSR) format that match the user-side positioning model. Combined with the bandwidth requirements under limited satellite communication resources and the PRN number of the visible satellites on the user side, complete the lightweight encoding and broadcasting of precise satellite correction products adapted to the bandwidth under limited satellite communication resources, thereby improving the convergence time.

[0013] 2) At the user end, combining lightweight OSR-based precision satellite orbit and clock error equivalent corrections, satellite-end ultra-wide lane comprehensive deviation corrections, satellite-end wide lane comprehensive deviation corrections, and satellite-end narrow lane comprehensive deviation correction products broadcast under limited satellite communication resources, a multi-frequency cascaded ionospheric-free ultra-wide lane (EWL)-wide lane (WL)-narrow lane (Narrow) product is constructed. The integer ambiguity fixing model (Lane, NL) includes fixed EWL integer ambiguity, wide-lane integer ambiguity fixing model, and narrow-lane integer ambiguity fixing model. To address the impact of minute-level latency on integer ambiguity fixing due to limited satellite communication resources, the EWL-WL-NL integrated bias correction information at the satellite end exhibits stability under minute-level latency. Furthermore, EWL, being a geometrically and ionosphere-free HMW (Hatch-Melbourne-Würbbena) combination, is unaffected by the decrease in accuracy of precise satellite correction products under minute-level latency, and its longest wavelength enables rapid integer ambiguity fixing. The WL and NL combination, by considering spatial signal ranging errors under minute-level latency, can compensate for the decrease in precision satellite orbit and clock error correction accuracy under minute-level latency, ultimately improving the success rate of integer ambiguity fixing under minute-level broadcast latency under limited satellite communication resources and enhancing positioning accuracy. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A schematic flowchart of a precise point positioning method under limited satellite communication resources is provided in one embodiment of this application; Figure 2 This is a schematic flowchart of another precise point positioning method under limited satellite communication resources provided in an embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] To make the objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, this application provides a precise point positioning method under satellite communication resource constraints, including: Step 101: On the system side, receive user data and precision satellite correction products in real time; the user data includes user location information and the PRN number of the satellite visible to the user; the precision satellite correction products include correction information for precision satellite orbit, clock error, phase deviation and code deviation.

[0019] Step 102: On the system side, based on the user data and the precision satellite correction product, correction data matching the user-end positioning model is generated; the correction data includes precision satellite orbit and clock error equivalent correction based on OSR format, satellite-end ultra-wide lane comprehensive deviation correction, satellite-end wide lane comprehensive deviation correction, and satellite-end narrow lane comprehensive deviation correction.

[0020] In practical applications, the satellite-end wide-lane integrated bias correction is to construct a geometrically correlated satellite-end integrated phase bias without ionospheric wide-lane combinations; the satellite-end narrow-lane integrated bias correction is to construct a geometrically correlated satellite-end integrated phase bias without ionospheric narrow-lane combinations.

[0021] Step 103: On the system side, combining the correction data and the bandwidth requirements under the limited satellite communication resources, the precision satellite correction product is lightweight encoded according to the user-visible satellite PRN number and broadcast to the user end; limited satellite communication resources generally refer to narrow communication bandwidth and low frequency.

[0022] In practical applications, at the system level, the data bits occupied by the precise satellite orbit and clock error equivalent correction based on OSR, the satellite-side ultra-wide lane comprehensive deviation correction, the satellite-side wide lane comprehensive deviation correction, and the satellite-side narrow lane comprehensive deviation correction information are combined. Based on the visible satellite situation at the user end, the aforementioned precise satellite correction products are lightweighted and encoded. If the bandwidth of the encoded visible satellite is greater than the broadcast bandwidth under limited satellite communication resources, the satellite with the smallest elevation angle is removed until the bandwidth of the encoded visible satellite is less than or equal to the broadcast bandwidth under limited satellite communication resources.

[0023] Step 104: At the user terminal, based on the real-time received satellite observations and broadcast ephemeris messages, the lightweight coded precision satellite correction product is parsed to determine the ultra-wide lane comprehensive deviation correction information, and the fixed EWL integer ambiguity is determined based on the ultra-wide lane comprehensive deviation correction information.

[0024] Step 105: At the user end, a fixed WL integer ambiguity is determined based on the fixed EWL integer ambiguity, real-time OSR-based precise satellite orbit and clock bias equivalent correction, wide-lane integer ambiguity fixed model, and satellite-end wide-lane comprehensive deviation correction matching the wide-lane integer ambiguity fixed model; the wide-lane integer ambiguity fixed model is a wide-lane integer ambiguity model based on inter-satellite differential multi-frequency geometric correlation ionosphere-free combination, wherein multi-frequency refers to a combination mode of three or more frequencies.

[0025] In practical applications, at the user end, considering the age of minute-level precision satellite correction products, a multi-frequency geometrically correlated ionosphere-free combined wide-lane integer ambiguity fixing model is constructed by adding space signal ranging constraints. Based on real-time OSR-based precision satellite orbit and clock error equivalent correction, satellite-end wide-lane comprehensive deviation correction matching the wide-lane integer ambiguity fixing model, and fixed EWL integer ambiguity, the wide-lane integer ambiguity of inter-satellite difference is fixed using the sequential least squares method.

[0026] Step 106: Based on the fixed EWL integer ambiguity, the fixed WL integer ambiguity, the real-time OSR-based precise satellite orbit and clock bias equivalent correction, the narrow-lane integer ambiguity fixed model, and the satellite-end narrow-lane comprehensive deviation correction matching the narrow-lane integer ambiguity fixed model, determine the user position under the narrow-lane fixed solution and update the current user position; the narrow-lane integer ambiguity fixed model is an ionosphere-free narrow-lane integer ambiguity model based on inter-satellite differences.

[0027] In practical applications, at the user end, considering the age of minute-level precision satellite correction products, a multi-frequency geometrically correlated ionosphere-free combined narrow-lane integer ambiguity fixed model is constructed by adding space signal ranging constraints. Based on real-time OSR-based precision satellite orbit and clock error equivalent correction, satellite-end narrow-lane comprehensive deviation correction matched with the narrow-lane integer ambiguity fixed model, and fixed EWL and WL integer ambiguities, the inter-satellite difference narrow-lane integer ambiguity is fixed using the sequential least squares method, and the position update under the narrow-lane fixed solution is completed.

[0028] Step 107: Send the current visible satellite PRN number and the updated user location to the system to complete precise single-point positioning.

[0029] In an exemplary embodiment, the OSR-based precise satellite orbit and clock bias equivalent correction is as follows: in, For precise satellite orbit and clock error equivalent correction based on OSR format, i Indicates the station number. s For the satellite system used,j For satellite PRN number; This represents the unit vector in the direction from the receiver to the satellite; The satellite orbit correction vector in the satellite orbit coordinate system is calculated from real-time precise satellite radial, normal, and tangential corrections and their rate of change parameters. This indicates the precision satellite clock error correction calculated using real-time precision satellite clock error parameters; This represents the user's location calculated using single-point positioning. It is the real-time precise satellite orbit position calculated from broadcast ephemeris and real-time precise satellite clock correction.

[0030] In an exemplary embodiment, the satellite-end ultra-wide lane integrated deviation correction is as follows: in, This refers to the satellite-end ultra-wide lane integrated bias correction, specifically the satellite-end ultra-wide lane HMW integrated phase and code bias correction. s For the satellite system used, j For satellite PRN number; and Representing satellite systems s The corresponding frequencies for 2-band and 3-band, in Hz; For the carrier phase satellite end offset correction of satellite j in satellite system s; For the carrier phase satellite end offset correction of satellite j in satellite system s; For the pseudorange satellite end offset correction of the 2-frequency satellite j in satellite system s; This is the pseudorange satellite end offset correction for satellite j in satellite system s at three frequencies.

[0031] In one exemplary embodiment, the satellite-end wide-lane integrated bias correction is as follows: in, This indicates the satellite-end wide lane integrated deviation correction; , and This represents the frequencies of frequency 1, frequency 2, and frequency 3 corresponding to satellite system s; For the carrier phase satellite end offset correction of frequency 1 corresponding to satellite j in satellite system s; For the carrier phase satellite end offset correction of satellite j in satellite system s; This is the satellite-end offset correction for the carrier phase of satellite j in satellite system s.

[0032] In one exemplary embodiment, the satellite-end narrow lane integrated bias correction is as follows: in, For satellite-end narrow lane integrated deviation correction; , These represent the frequencies of frequency 1 and frequency 2 corresponding to satellite system s, respectively. For the carrier phase satellite end offset correction of frequency 1 corresponding to satellite j in satellite system s; This is the satellite-end offset correction for the carrier phase of satellite j in satellite system s.

[0033] In one exemplary embodiment, the wide lane integer ambiguity fixed model is constructed based on fixed EWL integer ambiguity, minute-level precision satellite correction product age, and additional space signal ranging constraints. The narrow lane integer ambiguity fixed model is constructed based on fixed EWL integer ambiguity, fixed WL integer ambiguity, minute-level precision satellite correction product age, and additional space signal ranging constraints. The additional spatial signal ranging constraint is: in, The error is expressed in meters (m) relative to the equivalent correction for precise satellite orbit and clock errors based on the OSR format. To and The corresponding noise level is expressed in meters (m).

[0034] In another exemplary embodiment, this application provides a precise point positioning method under satellite communication resource constraints, such as... Figure 2 As shown, it includes: Step S1: On the system side, receive user location information and the PRN number of the satellite visible to the user in real time.

[0035] Step S2: At the system end, receive correction information for precise satellite orbit, clock error, phase deviation and code deviation in real time.

[0036] Step S3: On the system side, in conjunction with the PRN number of the visible satellite on the user side, construct the OSR-based precise satellite orbit and clock error equivalent correction, and the satellite-side ultra-wide lane comprehensive deviation correction, satellite-side wide lane comprehensive deviation correction, and satellite-side narrow lane comprehensive deviation correction information that match the user-side EWL-WL-NL cascaded non-ionized combined PPP positioning model.

[0037] The expression for the OSR-based precision satellite clock orbit equivalent correction can be expressed as: in, For OSR-based precision satellite clock orbit equivalent correction, where the subscript i Indicates the station number; The satellite orbit correction vector in the satellite orbit coordinate system is calculated from real-time precise satellite radial, normal, and tangential corrections and their rate of change parameters, and is expressed in meters (m). This represents the precision satellite clock bias correction calculated using real-time precision satellite clock bias parameters, in meters (m). This represents the user's location calculated using single-point positioning, in meters (m). It is the real-time precise satellite orbit position calculated from broadcast ephemeris and real-time precise satellite clock correction, in meters.

[0038] The aforementioned satellite-end ultra-wide lane integrated deviation correction is derived from the Hatch-Melbourne-Württemberg (HMW) model, and its expression can be represented as: in, For satellite-side ultra-wide lane HMW integrated bias correction, the superscript... s Indicates the satellite system used. j Indicates the satellite's PRN number; and Representing satellite systems s The corresponding frequencies for 2-band and 3-band, in Hz; This represents the observation-specific bias term, used to eliminate satellite-end decimal bias, in meters (m). L and P These represent carrier phase and pseudorange observations, respectively, in meters (m).

[0039] The expression for the satellite-end wide-lane integrated deviation correction can be expressed as: in, This indicates the satellite-end wide lane comprehensive deviation correction, in meters (m). Indicates satellite system s The corresponding frequency of 1, in Hz.

[0040] The expression for the satellite-end narrow lane integrated deviation correction can be expressed as: in, This indicates the satellite-end narrow lane integrated deviation correction, in meters (m).

[0041] Step S4: On the system side, based on the data bits occupied by the OSR-based precision satellite orbit and clock error equivalent correction, satellite-side ultra-wide lane comprehensive deviation correction, satellite-side wide lane comprehensive deviation correction, and satellite-side narrow lane phase deviation correction information, and combined with the visible satellite situation on the user side, the above precision satellite correction products are coded in a lightweight manner.

[0042] The aforementioned encoded information comprises three parts: a data header, a data body, and a data trailer. The data header includes the SYN code, epoch time, satellite system, and satellite ID. The data trailer uses a 24-bit checksum, verified using CRC24. The data body, within the limited remaining satellite communication resources, encodes information including the IODE of satellites visible to the user, OSR-based precise satellite orbit and clock error equivalent corrections, satellite-side ultra-wide lane comprehensive deviation corrections, satellite-side wide lane comprehensive deviation corrections, and satellite-side narrow lane comprehensive deviation corrections. This results in lightweight, precise satellite correction encoding under limited satellite communication resources.

[0043] Step S5: The broadcast of lightweight precision satellite correction information under limited satellite communication resources needs to be completed in conjunction with the bandwidth under limited satellite communication resources. If the amount of lightweight precision satellite correction information to be broadcast is greater than the bandwidth under limited satellite communication resources, all user-visible satellites are arranged from high to low elevation angle. Under the premise of ensuring that the horizontal accuracy factor is less than 2, the satellites with the worst observation quality are eliminated in turn until the bandwidth requirement under limited satellite communication resources is met, and the broadcast is completed.

[0044] Step S6: At the user end, receive and analyze lightweight precision satellite correction products, satellite observations, and broadcast ephemeris messages in real time, even with limited satellite communication resources.

[0045] Step S7: On the user side, construct an EWL integer ambiguity fixed model based on HMW combination, the expression of which is as follows: in, This represents the combined HMW observations of the ultra-wide lane, in meters (m). Indicates the ultra-wide lane wavelength, in meters (m). Represents the integer ambiguity of the non-differential ultra-wide alleyway, in units of weeks; This indicates the correction for the overall phase and code deviation of the ultra-wide lane HMW at the user end, in meters. This indicates the satellite-side ultra-wide lane integrated phase deviation correction, in meters.

[0046] Step S8: To achieve fixed EWL integer ambiguity under HMW combination, firstly, the satellite-related errors in HMW are corrected using real-time ultra-wide lane HMW integrated deviation correction information broadcast in short messages; secondly, the satellite with the largest elevation angle is selected as the reference satellite, and the ultra-wide lane HMW integrated phase deviation related to the user end is eliminated through inter-satellite single difference. Finally, the fixed EWL integer ambiguity is obtained by rounding down to the nearest integer.

[0047] Step S9: On the user end, based on the fixed EWL integer ambiguity, construct an ionospheric wide-lane integer ambiguity model based on inter-satellite difference, the expression of which is as follows; in, r Indicates the reference satellite number. The observations are represented as a combination of ionospheric pseudoranges at frequencies 1 and 2, in meters. Represented as ionospherically free-lane carrier phase observations, in meters (m); Indicates the station under inter-satellite single difference i Distance to the satellite, in meters; This represents the satellite clock bias under inter-satellite single-difference conditions, in meters (m). This represents the tropospheric delay error under inter-satellite single-difference, in meters (m). The wavelength represents the width ambiguity, in meters. This represents the wide-lane integer ambiguity under inter-satellite single-difference, in cycles; This indicates the wide-lane integrated deviation correction at the satellite end, in meters (m). Represents wide-lane carrier phase observations based on a combination of frequency 1 and frequency 2, in meters (m). Represents wide-lane carrier phase observations based on a combination of 2-frequency and 3-frequency signals, in meters (m). This indicates a fixed EWL integer ambiguity.

[0048] The above WL The selected frequency 1 and frequency 2 combined time reference is consistent with the time reference corrected by the precision satellite clock bias, and will not generate additional satellite-end dual-frequency ionospheric code deviation.

[0049] Step S10: To achieve WL integer ambiguity fixation, firstly, real-time OSR-based precision satellite orbit and clock bias equivalent correction and satellite-end wide-lane comprehensive deviation correction are used for short message broadcasting; secondly, considering the age of minute-level precision satellite correction products, compensation for minute-level precision satellite orbit and clock bias correction accuracy is achieved by adding satellite spatial signal ranging error as a state variable; finally, WL integer ambiguity fixation is completed through partial ambiguity fixation methods.

[0050] The above-mentioned approach, taking into account the age of minute-level precision satellite correction products, compensates for minute-level precision satellite orbit and clock error correction accuracy by adding the satellite's spatial signal ranging error as a state variable. The expression is as follows: in, The error is expressed in meters (m) relative to the OSR-based precision satellite orbit and clock error equivalent correction. The corresponding noise level is expressed in meters (m).

[0051] Step S11: On the user end, based on the fixed WL and EWL integer ambiguities, construct an ionospheric narrow-lane integer ambiguity model based on inter-satellite differences, the expression of which is as follows: in, These are the constructed ionosphere-free and ambiguity-free observations, in meters (m). Represented as ionospherically non-ionospherically narrow-lane carrier phase observations, in meters (m). The wavelength representing the ambiguity of two frequencies is expressed in meters. This represents the integer ambiguity of narrow alleyway under inter-satellite single difference, in cycles; This indicates the narrow lane overall deviation correction at the satellite end, in meters (m). This indicates a fixed WL integer ambiguity.

[0052] Step S12: To achieve NL integer ambiguity fixation, firstly, real-time OSR-based precision satellite orbit and clock bias equivalent correction, satellite-end wide lane comprehensive deviation correction, and satellite-end narrow lane comprehensive deviation correction are used in short message broadcasts; secondly, considering the age of minute-level precision satellite correction products, the accuracy of minute-level precision satellite orbit and clock bias correction is compensated by adding the satellite's spatial signal ranging error as a state variable; finally, the NL integer ambiguity is fixed through a partial ambiguity fixation method, thus completing the position update.

[0053] The above-mentioned approach, taking into account the age of minute-level precision satellite correction products, compensates for minute-level precision satellite orbit and clock error correction accuracy by adding the satellite's spatial signal ranging error as a state variable. The expression is as follows: Step S13: Send the currently visible satellite PRN number and user location to the system.

[0054] This application also provides a precise point positioning system under satellite communication resource constraints, including: The data receiving module is used to receive user data and precision satellite correction products in real time at the system end; the user data includes user location information and the PRN number of the satellite visible to the user; the precision satellite correction products include correction information for precision satellite orbit, clock error, phase deviation and code deviation.

[0055] The correction data generation module is used at the system end to generate correction data that matches the user-end positioning model based on the user data and the precision satellite correction product; the correction data includes precision satellite orbit and clock error equivalent correction based on OSR format, satellite-end ultra-wide lane comprehensive deviation correction, satellite-end wide lane comprehensive deviation correction, and satellite-end narrow lane comprehensive deviation correction.

[0056] The lightweight encoding module is used at the system end to perform lightweight encoding of the precision satellite correction product based on the user-visible satellite PRN number, taking into account the correction data and the bandwidth requirements under limited satellite communication resources, and then broadcasting it to the user end.

[0057] A fixed EWL integer ambiguity determination module is used at the user end to parse the lightweight coded precision satellite correction product based on real-time received satellite observations and broadcast ephemeris messages, determine the ultrawide lane comprehensive deviation correction information, and determine the fixed EWL integer ambiguity based on the ultrawide lane comprehensive deviation correction information.

[0058] A fixed WL integer ambiguity determination module is used at the user end to determine a fixed WL integer ambiguity based on the fixed EWL integer ambiguity, real-time OSR-based precise satellite orbit and clock bias equivalent correction, a wide-lane integer ambiguity fixed model, and a satellite-end wide-lane comprehensive deviation correction matching the wide-lane integer ambiguity fixed model; the wide-lane integer ambiguity fixed model is a wide-lane integer ambiguity model based on inter-satellite differential multi-frequency geometric correlation ionosphere-free combination.

[0059] The user location update module is used to determine the user's location under the narrow-lane fixed solution based on the fixed EWL integer ambiguity, the fixed WL integer ambiguity, real-time OSR-based precise satellite orbit and clock error equivalent correction, the narrow-lane integer ambiguity fixed model, and the satellite-end narrow-lane comprehensive deviation correction matched with the narrow-lane integer ambiguity fixed model, and update the current user's location; the narrow-lane integer ambiguity fixed model is an ionosphere-free narrow-lane integer ambiguity model based on inter-satellite differences.

[0060] The precise point positioning module is used to send the current visible satellite PRN number and the updated user location to the system to complete precise point positioning.

[0061] This application comprises two parts: lightweight coding and broadcasting of precise satellite correction products matched to the user-end positioning model, and precise point positioning with fixed ambiguities for multi-frequency ionospheric EWL-WL-NL at the user end. At the system end, it constructs OSR-based precise satellite orbit and clock error equivalent corrections, satellite-end ultra-wide lane comprehensive deviation corrections, satellite-end wide lane comprehensive deviation corrections, and satellite-end narrow lane comprehensive deviation corrections to match the user-end positioning model. Combined with bandwidth requirements under limited satellite communication resources and the PRN number of visible satellites at the user end, it completes lightweight coding and broadcasting of precise satellite correction products adapted to bandwidth constraints under limited satellite communication resources. At the user end, it constructs an integer ambiguity-fixed model for multi-frequency ionospheric EWL, WL, and NL cascaded precise point positioning.

[0062] First, by combining the comprehensive deviation correction of the ultra-wide lane HMW broadcast under limited satellite communication resources, the ultra-wide lane ambiguity is fixed based on the HMW combination. Second, by combining the equivalent correction of precise satellite orbit and clock error based on OSR, the comprehensive deviation correction of the satellite-end wide lane, and the fixed EWL ambiguity broadcast under limited satellite communication resources, the ionospheric WL ambiguity is fixed by adding space signal ranging constraints based on partial ambiguity fixing. Finally, by combining the equivalent correction of precise satellite orbit and clock error based on OSR, the comprehensive deviation correction of the satellite-end narrow lane, and the fixed EWL and WL ambiguities broadcast under limited satellite communication resources, the NL ambiguity is fixed by adding space signal ranging constraints based on partial ambiguity fixing, and the position solution based on NL fixing is calculated.

[0063] This application can adapt to broadcast bandwidth under limited satellite communication resources and alleviate the impact of the decrease in correction accuracy of minute-level latency precision satellite correction products on integer ambiguity fixation. While reducing communication costs, it can achieve rapid ambiguity fixation across the entire sea area, achieving positioning results from decimeter to centimeter level.

[0064] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments. The computer device can be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O), and a communication interface. The processor, memory, and I / O interface are connected via a system bus, and the communication interface is connected to the system bus via the I / O interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device stores data to be processed. The I / O interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with an external terminal via a network connection. When the computer program is executed by the processor, it implements the above-described methods.

[0065] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0066] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0067] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0068] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0069] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by hardware related to computer program instructions. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0070] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A precise point positioning method under the restriction of satellite communication resources, characterized in that, The method comprises the following steps: At the system end, real-time user data and precise satellite correction products are received; the user data comprises user position information and user visible satellite PRN number; the precise satellite correction products comprise precise satellite orbit, clock error and correction information of phase bias and code bias; At the system end, correction data matched with the positioning model of the user end is generated according to the user data and the precise satellite correction products; The correction data comprises OSR format-based precise satellite orbit and clock error equivalent correction, satellite end ultra-wide lane comprehensive bias correction, satellite end wide lane comprehensive bias correction and satellite end narrow lane comprehensive bias correction; At the system end, combined with the correction data and the bandwidth demand under the condition of limited satellite communication resources, the precise satellite correction products are encoded in a light weight manner according to the user visible satellite PRN number, and broadcast to the user end; At the user end, the light weight encoded precise satellite correction products are analyzed according to the real-time received satellite observation and broadcast ephemeris, the ultra-wide lane comprehensive bias correction information is determined, and the fixed EWL integer ambiguity is determined according to the ultra-wide lane comprehensive bias correction information; At the user end, the fixed WL integer ambiguity is determined according to the fixed EWL integer ambiguity, real-time OSR format-based precise satellite orbit and clock error equivalent correction, wide lane integer ambiguity fixed model and satellite end wide lane comprehensive bias correction matched with the wide lane integer ambiguity fixed model; the wide lane integer ambiguity fixed model is a wide lane integer ambiguity model based on inter-satellite difference and multi-frequency geometry correlation and ionosphere-free combination; The user position under the narrow lane fixed solution is determined according to the fixed EWL integer ambiguity, the fixed WL integer ambiguity, real-time OSR format-based precise satellite orbit and clock error equivalent correction, narrow lane integer ambiguity fixed model and satellite end narrow lane comprehensive bias correction matched with the narrow lane integer ambiguity fixed model; the narrow lane integer ambiguity fixed model is a narrow lane integer ambiguity model based on inter-satellite difference and ionosphere-free; The current user visible satellite PRN number and the updated user position are sent to the system end, and the precise point positioning is completed.

2. The precise point positioning method under the restriction of satellite communication resources according to claim 1, characterized in that, The OSR format-based precise satellite orbit and clock error equivalent correction is: wherein, is the equivalent correction of precise satellite orbit and clock error based on OSR format, denotes the station number, s is the satellite system used, is the satellite PRN number; denotes the unit vector from the receiver to the satellite direction; denotes the satellite orbit correction vector in the satellite orbit coordinate system; denotes the precise satellite clock correction calculated by using real-time precise satellite clock error parameters; denotes the user position calculated by the user single point positioning; is the real-time precise satellite orbit position calculated by the broadcast ephemeris and real-time precise satellite orbit correction.

3. The precise point positioning method under the restriction of satellite communication resources according to claim 1, characterized in that, The satellite end ultra-wide lane comprehensive bias correction is: wherein, is the satellite-end ultra-wide-lane combined bias correction, i.e., the satellite-end ultra-wide-lane HMW combined phase and code bias correction, s is the satellite system used, j is the satellite PRN number; and respectively represent the 2-frequency and 3-frequency of the satellite system s corresponding to the 2-frequency and 3-frequency; is the 2-frequency carrier phase satellite-end bias correction corresponding to satellite j in the satellite system s; is the 3-frequency carrier phase satellite-end bias correction corresponding to satellite j in the satellite system s; is the 2-frequency pseudorange satellite-end bias correction corresponding to satellite j in the satellite system s; is the 3-frequency pseudorange satellite-end bias correction corresponding to satellite j in the satellite system s.

4. The precise point positioning method under the restriction of satellite communication resources according to claim 1, characterized in that, The satellite end wide lane comprehensive bias correction is: wherein, denotes the satellite-end wide-lane combined bias correction; , and denote the frequencies of the 1st, 2nd and 3rd frequencies, respectively, for the satellite system s; is the carrier phase satellite-end bias correction for the 1st frequency for satellite j in the satellite system s; is the carrier phase satellite-end bias correction for the 2nd frequency for satellite j in the satellite system s; is the carrier phase satellite-end bias correction for the 3rd frequency for satellite j in the satellite system s.

5. The precise point positioning method under the restriction of satellite communication resources according to claim 1, characterized in that, The satellite end narrow lane comprehensive bias correction is: wherein, is the satellite end narrow-lane combined bias correction; , respectively represent the frequencies of the 1 -frequency and 2- frequency corresponding to the satellite system s; is the 1 -frequency carrier phase satellite end bias correction corresponding to satellite j in the satellite system s; is the 2- frequency carrier phase satellite end bias correction corresponding to satellite j in the satellite system s.

6. The precise point positioning method under the restriction of satellite communication resources according to claim 1, characterized in that, The wide lane integer ambiguity fixed model is constructed based on the fixed EWL integer ambiguity, minute-level precise satellite correction product age and additional spatial signal ranging constraint; The narrow lane integer ambiguity fixed model is constructed based on the fixed EWL integer ambiguity, fixed WL integer ambiguity, minute-level precise satellite correction product age and additional spatial signal ranging constraint; The additional spatial signal ranging constraint is: wherein, is the error amount relative to the equivalent correction of precise satellite orbit and clock error based on the OSR format; is the error amount relative to the equivalent correction of precise satellite orbit and clock error based on the OSR format; is the corresponding noise.

7. A precise point positioning system under the restriction of satellite communication resources, characterized in that, The method comprises the following steps: The data receiving module is configured to receive user data and precise satellite correction products in real time at the system end, wherein the user data comprises user position information and user visible satellite PRN numbers, and the precise satellite correction products comprise precise satellite orbits, clock differences, and correction information of phase bias and code bias. The correction data generation module is configured to generate correction data matched with a user end positioning model according to the user data and the precise satellite correction products at the system end. The correction data comprises OSR format-based precise satellite orbit and clock difference equivalent correction, satellite end ultra-wide lane comprehensive bias correction, satellite end wide lane comprehensive bias correction, and satellite end narrow lane comprehensive bias correction. The lightweight coding module is configured to perform lightweight coding on the precise satellite correction products according to the user visible satellite PRN numbers and broadcast the lightweight coded precise satellite correction products to the user end, in combination with the correction data and bandwidth demand under satellite communication resource limitation at the system end. The fixed EWL integer ambiguity determination module is configured to determine ultra-wide lane comprehensive bias correction information according to real-time received satellite observations and broadcast ephemeris messages, and determine fixed EWL integer ambiguity according to the ultra-wide lane comprehensive bias correction information at the user end. The fixed WL integer ambiguity determination module is configured to determine fixed WL integer ambiguity according to the fixed EWL integer ambiguity, real-time OSR format-based precise satellite orbit and clock difference equivalent correction, a wide lane integer ambiguity fixed model, and satellite end wide lane comprehensive bias correction matched with the wide lane integer ambiguity fixed model at the user end. The user position updating module is configured to determine user position under narrow lane fixed solution according to the fixed EWL integer ambiguity, the fixed WL integer ambiguity, real-time OSR format-based precise satellite orbit and clock difference equivalent correction, a narrow lane integer ambiguity fixed model, and satellite end narrow lane comprehensive bias correction matched with the narrow lane integer ambiguity fixed model, and update the current user position. The precise point positioning module is configured to send the current user visible satellite PRN numbers and the updated user position to the system end to complete precise point positioning.

8. A computer device comprising: The memory, the processor, and the computer program stored in the memory and executable on the processor are characterized in that the processor executes the computer program to implement the precise point positioning method under satellite communication resource limitation according to any one of claims 1-6.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the precise point positioning method under satellite communication resource limitation according to any one of claims 1-6.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the precise point positioning method under satellite communication resource limitation according to any one of claims 1-6.

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