A carrier phase ambiguity fast fixing system and method
By integrating high-orbit navigation satellites and low-orbit satellites, and utilizing the broadcasting of multi-band signals and navigation enhancement signals, the problem of long fixed time for carrier phase ambiguity in traditional GNSS positioning systems has been solved, achieving rapid and high-precision positioning.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN INSTITUE OF SPACE RADIO TECH
- Filing Date
- 2023-09-28
- Publication Date
- 2026-07-03
Smart Images
Figure CN117368951B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a system and method for rapidly fixing carrier phase ambiguity, belonging to the field of navigation and positioning technology. Background Technology
[0002] Global satellite navigation systems, represented by BeiDou, operate continuously and stably, providing navigation, positioning, and timing services to users worldwide. However, when using traditional GNSS positioning, it takes a long time to fix the carrier phase ambiguity.
[0003] With the rapid development of the social economy, the demand for fast convergence high-precision positioning in various industries is increasing day by day. Traditional navigation systems and equipment can no longer achieve fast ambiguity fixation and thus fast convergence high-precision positioning, while many users need fast convergence high-precision positioning services. Summary of the Invention
[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a system and method for fast carrier phase ambiguity fixing, thereby achieving fast fixing of carrier phase ambiguity.
[0005] The technical solution of this invention is: a carrier phase ambiguity fast fixing system, comprising:
[0006] The ground control system monitors, controls, and manages the navigation satellite constellation and the low-Earth orbit satellite constellation; it generates various types of navigation information based on the received satellite status information and control and management information, and uploads these navigation information to the navigation satellites and low-Earth orbit satellites.
[0007] A navigation satellite constellation consists of multiple navigation satellites distributed across multiple medium and high orbit planes, used to broadcast medium and high orbit navigation signals to the world or specific regions.
[0008] A low-Earth orbit (LEO) satellite constellation comprises multiple LEO satellites distributed across multiple LEO planes, used to broadcast LEO navigation and communication signals globally or to specific regions; the LEO and high-Earth orbit (MEO) navigation signals and LEO navigation signals each include navigation signals in at least two frequency bands.
[0009] The user receiver receives communication signals broadcast by low-Earth orbit (LEO) satellite constellations, as well as medium- and high-Earth orbit (MEO) navigation signals broadcast by navigation satellite constellations, or LEO navigation signals broadcast by LEO satellite constellations, or MEO and LEO navigation signals broadcast jointly by navigation satellite constellations and LEO satellite constellations, to achieve positioning.
[0010] Furthermore, both the medium-to-high orbit navigation signals and the low-orbit navigation signals include navigation signals and navigation information of their respective navigation satellites:
[0011] The navigation signal includes an L-band signal and a navigation enhancement signal; the L-band signal has a frequency range of 1 to 2 GHz, the center frequency of the navigation enhancement signal is above 22.3 GHz, the main lobe bandwidth of the navigation enhancement signal exceeds 20.46 MHz, and the signal grounding power is higher than -155 dBw.
[0012] The navigation information includes basic navigation information and navigation enhancement information; wherein the basic navigation information includes broadcast ephemeris, broadcast clock bias, broadcast almanac, broadcast code phase deviation, and satellite integrity; and the navigation enhancement information includes orbit clock bias correction, satellite attitude, antenna phase center and variation, hardware delay correction, and wide-lane and narrow-lane fractional deviation of L-band signals.
[0013] The L-band signal broadcasts signals at two or more frequency points, including BeiDou B1I, B1c, B2a, and B3I.
[0014] Furthermore, the center frequency points of the navigation enhancement signals in the medium-high orbit navigation signals and low orbit navigation signals are determined to be the same or different according to requirements.
[0015] Furthermore, the navigation enhancement signal is coherently generated with the L-band signal, and they share the same frequency reference.
[0016] Furthermore, the user receiver achieves positioning based on the L-band signal and navigation enhancement signal in the medium-high orbit navigation signal, or based on the L-band signal and navigation enhancement signal in the low orbit navigation signal, or simultaneously based on the L-band signal and navigation enhancement signal in both the medium-high orbit navigation signal and the low orbit navigation signal.
[0017] The method for fast carrier phase ambiguity fixing implemented according to the aforementioned fast carrier phase ambiguity fixing system includes:
[0018] At a certain time t, the user receiver n Simultaneously, it receives L-band navigation signals and navigation enhancement signals broadcast by navigation satellite constellations and low-Earth orbit satellite constellations, and generates pseudorange and carrier phase measurements of the L-band navigation signals, as well as pseudorange and carrier phase measurements of the navigation enhancement signals.
[0019] The user receiver simultaneously receives t n The system continuously generates navigation enhancement information from navigation satellites and low-Earth orbit satellites, and extracts basic navigation information and navigation enhancement information respectively. Receiving navigation enhancement information includes: receiving navigation information broadcast by the navigation satellite constellation itself; receiving navigation information broadcast by the low-Earth orbit satellite constellation communication frequency band; and receiving navigation information broadcast by the low-Earth orbit satellite constellation navigation enhancement frequency band.
[0020] The user receiver uses the received pseudorange and carrier phase measurements, along with the received basic navigation information and navigation enhancement information, to calculate the correction values for the navigation satellite constellation and low-Earth orbit satellite constellation observations, and executes the carrier phase ambiguity fixing method to achieve positioning.
[0021] Furthermore, the calculation of the correction amount for the observations of the navigation satellite constellation and the low-Earth orbit satellite constellation includes: generating the position and clock difference of the navigation satellite constellation and the low-Earth orbit satellite constellation at the signal transmission time based on the navigation information of the navigation satellite constellation and the low-Earth orbit satellite constellation, and calculating the correction amount for the observations of the navigation satellite constellation and the low-Earth orbit satellite constellation.
[0022] Furthermore, the step of generating the position and clock bias of the navigation satellite constellation and the low-Earth orbit satellite constellation at the signal transmission time based on the navigation information of the navigation satellite constellation and the low-Earth orbit satellite constellation includes:
[0023] The received pseudorange and carrier phase measurements are evaluated, and navigation satellites and low-Earth orbit satellites that simultaneously possess L-band navigation signal measurements and navigation enhancement signal measurements are statistically analyzed.
[0024] Using basic navigation information, the positions and clock biases of all navigation satellites and low-Earth orbit satellites that simultaneously possess L-band navigation signal measurements and navigation augmentation signal measurements;
[0025] Based on the position and clock error, the orbit clock error correction amount in the received navigation enhancement information is used to make corrections, and the centroid position and clock error correction amount of the navigation satellite and the low-Earth orbit satellite are obtained.
[0026] Correcting the transmission position of signals at different frequencies based on the centroid positions of navigation satellites and low-Earth orbit satellites: The transmission position of signals is corrected using the antenna phase center in the navigation enhancement information;
[0027] The transmission hardware delay of pseudorange for signals at different frequencies is corrected based on the clock bias correction.
[0028] Furthermore, the correction values for calculating the observations of the navigation satellite constellation and the low-Earth orbit satellite constellation include:
[0029] Errors related to the satellite are corrected through Earth rotation correction, spacetime curvature correction, special relativity correction, and antenna phase winding correction.
[0030] Errors related to the propagation path are corrected by correcting tropospheric delay using a projection function;
[0031] By correcting for Earth solid tides and ocean tides, errors related to the receiver are corrected.
[0032] Furthermore, the carrier phase ambiguity fixing method includes:
[0033] Using the navigation enhancement signals received from navigation satellites and low-orbit satellites, as well as satellite positions and clock errors, the preliminary user receiver position is calculated based on single-point positioning using the least squares method.
[0034] Based on the initial user receiver position, the changes in the satellite antenna phase center are corrected, and the changes in the user receiver antenna phase center are also corrected.
[0035] Using the corrected satellite position and clock error, the L-band observations are corrected using the correction values of the observations. Using the dual-frequency ionospheric formula, the combined dual-frequency ionospheric observations of navigation satellites and low-Earth orbit satellites are obtained.
[0036] The ambiguity of the wide lane is determined by utilizing the decimal deviation of the wide lane in the navigation enhancement information;
[0037] Based on the dual-frequency ionosphere-free combined observation and wide-lane ambiguity, a combined observation including the fractional part of narrow-lane ambiguity and true distance is obtained;
[0038] The narrow-lane ambiguity is fixed by using pseudorange observations of navigation enhancement signals and combined observations including the fractional part of the narrow-lane ambiguity and the true range.
[0039] The advantages of this invention compared to the prior art are:
[0040] (1) This invention achieves rapid broadcasting of various correction quantities for high-precision positioning by integrating high-orbit navigation satellites and low-orbit satellites.
[0041] (2) By increasing the broadcast of navigation enhancement signals, this invention provides users with a pseudorange observation with small error and no ionospheric influence for ambiguity fixation, thereby achieving rapid fixation of carrier phase ambiguity. Attached Figure Description
[0042] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0043] Figure 1 This is a schematic diagram of an ambiguity fixing system according to Embodiment 1 of the present invention;
[0044] Figure 2 This is a schematic diagram of an ambiguity fixing system according to Embodiment 2 of the present invention;
[0045] Figure 3 This is a schematic diagram of an ambiguity fixing system according to Embodiment 3 of the present invention;
[0046] Figure 4 This is a schematic diagram of an ambiguity fixing system according to Embodiment 4 of the present invention;
[0047] Figure 5 This is a schematic diagram of an ambiguity fixing system according to Embodiment 5 of the present invention;
[0048] Figure 6 This is a schematic diagram of an ambiguity fixing system provided according to Embodiment Six of the present invention;
[0049] Figure 7 This is a schematic diagram of an ambiguity fixing system provided according to Embodiment 7 of the present invention;
[0050] Figure 8 This is a schematic flowchart of an ambiguity fixing method according to Embodiment 8 of the present invention;
[0051] Figure 9 This is a schematic flowchart of an ambiguity fixing method according to Embodiment 9 of the present invention;
[0052] Figure 10 This is a schematic flowchart of an ambiguity fixing method according to Embodiment 10 of the present invention;
[0053] Figure 11 This is a schematic flowchart of an ambiguity fixing method according to Embodiment Eleven of the present invention;
[0054] Figure 12 This is a schematic diagram of a method for fixing ambiguity according to Embodiment Twelve of the present invention. Detailed Implementation
[0055] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.
[0056] The following description, in conjunction with the accompanying drawings, provides a more detailed account of a carrier phase ambiguity fast fixing system and method provided in this application. Specific implementation methods may include:
[0057] A carrier phase ambiguity fast fixing system includes:
[0058] A navigation satellite constellation consists of multiple navigation satellites distributed across multiple medium- and high-Earth orbits. It can be a single constellation or multiple constellations, and it can provide stable coverage globally or in a specific region. A low-Earth orbit (LEO) satellite constellation consists of multiple LEO satellites distributed across multiple low-Earth orbits. It can be a single constellation or multiple constellations, and it can provide stable coverage globally or in a specific region. A ground control system monitors, controls, and manages the navigation satellite constellation and the LEO satellite constellation, generates and processes navigation information, and uploads various types of navigation information. User receivers receive navigation signals and information broadcast by the navigation satellite constellation and the LEO satellite constellation, and can use navigation signal measurements and navigation information to achieve positioning.
[0059] According to another aspect of the present invention, a navigation satellite constellation is provided, comprising:
[0060] Navigation satellites broadcast navigation signals and their own navigation information to users. The navigation signals further include L-band ranging signals and navigation enhancement signals. The L-band ranging signal operates between 1 and 2 GHz, broadcasting signals at two or more frequencies; the navigation enhancement signal's center frequency is above 22.3 GHz. The navigation information further includes basic navigation information and navigation enhancement information. The navigation enhancement signal and the L-band signal are coherently generated; the hardware delays of the L-band signal and navigation enhancement signal transmission on the satellite can be precisely calibrated; the relative centroid positions of the L-band signal transmitting antenna and the navigation enhancement signal transmitting antenna on the satellite are completely known; the phase center offset and variation of the L-band signal transmitting antenna and the navigation enhancement signal transmitting antenna can be precisely calibrated; and the navigation satellite's flight attitude is known and simultaneously broadcast to users.
[0061] According to another aspect of the present invention, a low-Earth orbit satellite constellation is provided, comprising:
[0062] Low-Earth orbit (LEO) satellites broadcast navigation signals to users. These navigation signals are further characterized by L-band signals and navigation enhancement signals. The L-band ranging signal operates between 1 and 2 GHz, broadcasting signals at two or more frequencies. The L-band ranging signal from the LEO satellite can share the same frequency as the L-band ranging signal broadcast by the navigation satellite, or they can be different frequencies. The navigation enhancement signal has a center frequency above 22.3 GHz and can share the same frequency as the navigation enhancement signal broadcast by the navigation satellite, or they can be different frequencies. LEO satellites rapidly broadcast navigation information to users, including basic navigation information and navigation enhancement information. LEO satellites rapidly broadcast navigation information to users via communication frequencies; simultaneously, they also rapidly broadcast navigation information via navigation enhancement signals. The navigation information includes navigation information from navigation satellites within the low-Earth orbit (LEO) satellite's field of view and navigation information from LEO satellites in adjacent orbital planes. The navigation enhancement signals broadcast by LEO satellites are coherently generated with the same frequency reference. The hardware delays of the L-band signals and navigation enhancement signals transmitted on the satellite can be precisely calibrated. The relative positions of the transmitting antennas for the L-band signals and navigation enhancement signals on the satellite are completely known. The offset and variation of the antenna phase centers of the transmitting antennas for the L-band signals and navigation enhancement signals can be precisely calibrated. The flight attitude of the LEO satellites is known and broadcast to users simultaneously.
[0063] According to another aspect of the present invention, a ground operation control system is provided, comprising:
[0064] The system receives navigation signals from the navigation satellite constellation and the low-Earth orbit (LEO) satellite constellation through multiple ground-based monitoring stations, monitors the satellite status, and transmits the information to the processing center. It also controls and manages the navigation satellite constellation and the LEO satellite constellation, maintaining their system time. The processing center uses the information received from the monitoring stations to generate navigation information. Gateway stations then upload the navigation information generated by the processing center to the navigation satellites and the LEO satellites respectively.
[0065] According to another aspect of the present invention, a user receiver is provided, comprising:
[0066] The user receiver can simultaneously receive L-band signals and navigation enhancement signals broadcast by navigation satellites and low-Earth orbit satellites; the user has the ability to receive communication band signals broadcast by low-Earth orbit satellites; the user receiver can receive and parse navigation information; the user receiver can use the received signals to generate corresponding pseudorange and carrier phase measurements; the user receiver can use pseudorange and carrier phase measurements and corresponding navigation information to quickly fix carrier phase ambiguity. The tracking loops for receiving L-band signals and navigation enhancement signals share the same receiver clock; the hardware delays of L-band signals and navigation enhancement signals during transmission from the antenna to the receiving loop can be precisely calibrated; the installation positions of the L-band signal antenna and the navigation enhancement signal antenna on the receiver, as well as the offset and changes in the antenna phase center, can be precisely calibrated; the receiver can receive signals from the navigation satellite constellation or the LEO satellite constellation, or simultaneously receive signals from both; the receiver must simultaneously receive both L-band navigation signals and navigation enhancement signals; the receiver can parse and store the navigation enhancement information broadcast by the satellites; the receiver has the computational capability to achieve user receiver positioning based on the navigation enhancement information and observations; during positioning, the receiver can execute a fast carrier phase ambiguity fixing algorithm.
[0067] According to another aspect of the present invention, a method for fast fixing of carrier phase ambiguity is provided, comprising:
[0068] Simultaneously receive navigation satellites and low-orbit satellites The system broadcasts L-band navigation signals and navigation enhancement signals, and receives navigation enhancement information from corresponding satellites (the navigation satellites that generated the measurements and the low-Earth orbit satellites). The receiver analyzes the navigation enhancement information to extract the broadcast messages of the navigation satellites and low-Earth orbit satellites, real-time high-precision orbit clock corrections, hardware delays, phase delays, antenna phase centers and their changes, various basic navigation information and navigation enhancement information of the satellites' flight attitudes; the user receiver uses pseudorange and carrier phase measurements, along with the navigation information, to perform a rapid carrier phase ambiguity fixing method.
[0069] According to another aspect of the present invention, a method for fast fixing of carrier phase ambiguity is provided, comprising:
[0070] Based on the navigation information, the precise positions and precise clock errors of the navigation satellite and the low-Earth orbit satellite are generated at the signal transmission time; based on the navigation information, the correction values of the observations of the navigation satellite and the low-Earth orbit satellite are generated; using the relevant information calculated above, the user receiver executes a method for rapid carrier phase ambiguity fixing.
[0071] According to another aspect of the present invention, a method for calculating the precise positions and precise clock biases of navigation satellites and low-Earth orbit satellites is provided, comprising:
[0072] The system statistically analyzes navigation satellites and low-Earth orbit (LEO) satellites that simultaneously possess L-band measurements and navigation enhancement signal measurements. Using the basic navigation message, it calculates the positions (centroid positions) and clock errors of all navigation and LEO satellites. It then uses high-precision orbit and clock error corrections from the received navigation enhancement message for correction, obtaining precise positions (centroid positions) and precise clock error corrections for the navigation and LEO satellites. Further corrections are made to the transmission positions of signals at different frequencies, and the transmission hardware delay of pseudoranges at different frequencies is further corrected.
[0073] According to another aspect of the present invention, a method for correcting observation errors of navigation satellites and low-Earth orbit satellites is provided, characterized by further comprising:
[0074] The corrections are related to satellites, mainly involving corrections for Earth's rotation, the effects of spacetime curvature, special relativity, and antenna phase winding (the correction methods mainly use mature correction models and methods); corrections are related to propagation paths, using known models and projection functions to correct tropospheric delay; and corrections are related to receivers, using known models to correct for Earth's solid tides and ocean tides.
[0075] According to another aspect of the present invention, a method for fast fixing of carrier phase ambiguity is provided, characterized by further comprising:
[0076] Using the received navigation enhancement signals from navigation satellites and low-Earth orbit satellites, and the satellite positions and clock biases calculated in steps 304 and 305, a preliminary user receiver position is calculated based on the known least squares method for single-point positioning. Based on the user receiver position, the phase center variation of the satellite antennas is corrected, and the phase center variation of the user receiver antennas is also corrected. Using the corrected precise satellite positions and clock biases, and the corrected L-band observations, the known dual-frequency ionospheric-free formula is used to obtain the combined dual-frequency ionospheric-free observations of the navigation satellites and low-Earth orbit satellites. The wide-lane ambiguity is determined using the wide-lane fractional deviation in the broadcast navigation information. Based on the combined dual-frequency ionospheric-free observations and wide-lane ambiguity calculated in steps 503 and 504, the narrow-lane ambiguity including the fractional part and the true range combination are combined to obtain the true range combination. Since the frequency of the navigation enhancement signal is above 22.3 GHz and the landing power is high, the ionospheric influence on the pseudorange of the navigation enhancement signal is very small, and the high landing power results in a small measurement error.
[0077] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below.
[0078] The solution provided in the embodiments of this application includes:
[0079] Example 1
[0080] Figure 1 A schematic diagram of a carrier phase ambiguity fast fixing system according to Embodiment 1 of the present invention is shown.
[0081] A navigation satellite constellation consists of multiple navigation satellites distributed across multiple medium and high orbital planes. It can be a single constellation or multiple constellations. The navigation satellites broadcast navigation signals T1 (not referring to a specific signal, but a general term for all signals) and can achieve stable coverage of the globe or a specific region.
[0082] A low-Earth orbit (LEO) satellite constellation consists of multiple LEO satellites distributed across multiple LEO planes. It can be a single constellation or multiple constellations. LEO satellites broadcast navigation signal T2 (not referring to a specific signal, but a general term for all signals) and communication signal C1, and can achieve stable coverage of the globe or a specific region.
[0083] The ground control system monitors and manages the navigation signals broadcast by the navigation satellite constellation and the low-Earth orbit (LEO) satellite constellation. The processing center processes the navigation information and uploads various types of navigation information to the navigation satellites and LEO satellites via the K1 and K2 uplinks. Multiple ground-based monitoring stations receive navigation signals from the navigation satellite constellation and LEO satellite constellation, monitor the satellite status, and transmit the information to the processing center. The system controls and manages the navigation satellite constellation and LEO satellite constellation, maintaining their system time. The processing center uses the information received from the monitoring stations to generate navigation information. Gateway stations upload the navigation information generated by the processing center to the navigation satellites and LEO satellites.
[0084] The user receiver receives navigation signals and information broadcast by navigation satellite constellations and low-Earth orbit (LEO) satellite constellations, and can simultaneously achieve positioning using navigation signal measurements and navigation information. The user receiver can simultaneously receive L-band signals and navigation enhancement signals broadcast by navigation satellites and LEO satellites; it has the capability to receive communication band signals broadcast by LEO satellites; the user receiver can receive and interpret navigation information; the user receiver can generate corresponding pseudorange and carrier phase measurements using the received signals; and the user receiver can quickly fix carrier phase ambiguities using pseudorange and carrier phase measurements and the corresponding navigation information. The tracking loops for receiving L-band signals and navigation enhancement signals share the same receiver clock; the hardware delays of L-band signals and navigation enhancement signals during transmission from the antenna to the receiving loop can be precisely calibrated; the installation positions of the L-band signal antenna and the navigation enhancement signal antenna on the receiver, as well as the offset and changes in the antenna phase center, can be precisely calibrated; the receiver can receive signals from the navigation satellite constellation or the LEO satellite constellation, or simultaneously receive signals from both; the receiver must simultaneously receive both L-band navigation signals and navigation enhancement signals; the receiver can parse and store the navigation enhancement information broadcast by the satellites; the receiver has the computational capability to achieve user receiver positioning based on the navigation enhancement information and observations; during positioning, the receiver can execute a fast carrier phase ambiguity fixing algorithm.
[0085] Example 2
[0086] Figure 2 A schematic diagram of a rapid ambiguity fixing system according to Embodiment 2 of the present invention is shown.
[0087] Navigation satellites broadcast navigation signals and their own navigation information to users: Navigation signal T1 is further characterized by L-band ranging signals and navigation enhancement signals. The L-band ranging signal operates between 1 and 2 GHz, broadcasting signals at two or more frequencies; the center frequency of the navigation enhancement signal is above 22.3 GHz. Navigation information is further characterized by basic navigation information and navigation enhancement information. The navigation enhancement signal and the L-band signal are coherently generated; the hardware delays of the L-band signal and navigation enhancement signal transmission on the satellite can be precisely calibrated; the relative centroid positions of the transmitting antennas for the L-band signal and the navigation enhancement signal on the satellite are completely known; the phase center offset and variation of the transmitting antennas for the L-band signal and the navigation enhancement signal can be precisely calibrated; the flight attitude of the navigation satellite is known and broadcast to users simultaneously.
[0088] Example 3
[0089] Figure 3 A schematic diagram of a rapid ambiguity fixing system according to Embodiment 3 of the present invention is shown.
[0090] Low-Earth orbit (LEO) satellites broadcast navigation signal T2 to users. Navigation signal T2 is further characterized by L-band signals and navigation enhancement signals. The L-band ranging signal operates between 1 and 2 GHz, broadcasting signals at two or more frequencies. The L-band ranging signal broadcast by the LEO satellite can have the same frequency as the L-band ranging signal broadcast by the navigation satellite, or a different frequency. The navigation enhancement signal has a center frequency above 22.3 GHz and can have the same frequency as the navigation enhancement signal broadcast by the navigation satellite, or a different frequency. LEO satellites rapidly broadcast navigation information to users, including basic navigation information and navigation enhancement information. LEO satellites rapidly broadcast navigation information to users via communication frequency band C1; simultaneously, LEO satellites also rapidly broadcast navigation information via navigation enhancement signals. The navigation information includes navigation information from navigation satellites within the low-Earth orbit (LEO) satellite's field of view and navigation information from LEO satellites in adjacent orbital planes. The navigation enhancement signals broadcast by LEO satellites are coherently generated with the same frequency reference. The hardware delays of the L-band signals and navigation enhancement signals transmitted on the satellite can be precisely calibrated. The relative positions of the transmitting antennas for the L-band signals and navigation enhancement signals on the satellite are completely known. The offset and variation of the antenna phase centers of the transmitting antennas for the L-band signals and navigation enhancement signals can be precisely calibrated. The flight attitude of the LEO satellites is known and broadcast to users simultaneously.
[0091] Example 4
[0092] Figure 4 A schematic diagram of a rapid ambiguity fixing system according to Embodiment 4 of the present invention is shown.
[0093] The navigation information that low-Earth orbit (LEO) satellites rapidly broadcast to users includes navigation information from LEO satellites in adjacent orbital planes and those in the same orbital plane that are mutually visible.
[0094] like Figure 4 As shown, low-orbit satellites With low-orbit satellites Low-Earth orbit satellites simultaneously in adjacent or the same orbital plane With low-orbit satellites Mutual visibility, low-orbit satellites In addition to its own navigation information, the broadcast navigation information also includes that from low-Earth orbit satellites. Navigation information, Low Earth Orbit satellites and They are not on the same orbital plane, therefore No broadcast Navigation information.
[0095] Example 5
[0096] Figure 5 A schematic diagram of a rapid ambiguity fixing system according to Embodiment 5 of the present invention is shown.
[0097] The navigation information rapidly broadcast to users by low-Earth orbit (LEO) satellites includes navigation information from navigation satellites within the LEO satellite's field of view. The navigation information is further characterized by being a retransmission of information from navigation satellites demodulated by the LEO satellite.
[0098] like Figure 5 As shown, low-orbit satellites visible Navigation satellites, low-Earth orbit satellites broadcast Navigation information from navigation satellites, navigation satellites For low-orbit satellites Invisible; navigation satellites do not broadcast navigation satellite information. Navigation information.
[0099] Example 6
[0100] Figure 6 A schematic diagram of a rapid ambiguity fixing system according to Embodiment Six of the present invention is shown.
[0101] The user receiver can simultaneously receive L-band signals and navigation enhancement signals broadcast by navigation satellites and low-Earth orbit satellites; the user has the ability to receive communication band signals broadcast by low-Earth orbit satellites; the user receiver can receive and parse navigation information; the user receiver can use the received signals to generate corresponding pseudorange and carrier phase measurements; the user receiver can use pseudorange and carrier phase measurements and corresponding navigation information to quickly fix carrier phase ambiguity.
[0102] Example 7
[0103] Figure 7 A schematic diagram of a rapid ambiguity fixing system according to Embodiment 7 of the present invention is shown.
[0104] The user receiver is characterized by its ability to receive communication band signals broadcast by low-Earth orbit (LEO) satellites and demodulate navigation enhancement information. It is also characterized by the fact that the tracking loops for receiving L-band signals and navigation enhancement signals share the same receiver clock. Furthermore, the hardware delay of the L-band signals and navigation enhancement signals during transmission from the antenna to the receiving loop can be precisely calibrated. The installation positions of the L-band signal antenna and the navigation enhancement signal antenna on the receiver, as well as the offset and changes in the antenna phase center, can be precisely calibrated. The receiver can receive signals from either the navigation satellite constellation or the LEO satellite constellation, or simultaneously from both. It must simultaneously receive both the L-band navigation signal and the navigation enhancement signal. The receiver can parse and store the navigation enhancement information broadcast by the satellites. It possesses the computational capability to achieve user receiver positioning based on the navigation enhancement information and observations. During positioning, the receiver can execute a fast carrier phase ambiguity fixing algorithm.
[0105] Example 8
[0106] Figure 8 A schematic flowchart of an ambiguity fixing method according to Embodiment 8 of the present invention is shown.
[0107] At a certain moment t n Simultaneously receive navigation satellites and low-orbit satellites The broadcast L-navigation signal and navigation enhancement signal respectively generate pseudorange measurements of the L-navigation signal. Where i represents the number of pseudoranges, j represents different frequencies, and the carrier phase measurement value is... pseudorange measurements for generating navigation augmentation signals Carrier phase measurement value Depending on the actual positioning situation, H and N may be the same or different; receive navigation enhancement information from the corresponding satellites (navigation satellites and low-Earth orbit satellites that generate the measurement values). Methods of receiving information include: receiving navigation information broadcast by the navigation satellites themselves (this method requires a relatively long time to acquire due to limitations in landing power and information rate); receiving navigation information broadcast in the communication frequency bands of low-Earth orbit satellites (this allows for rapid acquisition of navigation information); and receiving navigation information broadcast in the navigation enhancement frequency bands of low-Earth orbit satellites (this also allows for rapid acquisition of navigation information).
[0108] Using the methods described above, the receiver extracts broadcast messages from navigation satellites and low-Earth orbit satellites, real-time high-precision orbit clock corrections, hardware delays, phase delays, antenna phase centers and their changes, various basic navigation information and navigation enhancement information related to the satellite's flight attitude (to achieve rapid fixation of carrier phase ambiguity and shorten positioning time, the receiver should be capable of receiving low-Earth orbit satellite communication frequency bands); the user receiver uses the received pseudorange and carrier phase measurements, along with the received navigation information, to execute a rapid carrier phase ambiguity fixation method.
[0109] Example 9
[0110] Figure 9 A schematic flowchart of an ambiguity fixing method according to Embodiment 9 of the present invention is shown.
[0111] Based on the navigation information, the precise positions and precise clock biases of the navigation satellite and the low-Earth orbit satellite at the signal transmission time are generated; based on the navigation information, the correction values of the observations of the navigation satellite and the low-Earth orbit satellite are generated; based on the relevant information calculated above, the user receiver executes a method for rapid carrier phase ambiguity fixing.
[0112] Example 10
[0113] Figure 10 A schematic flowchart of an ambiguity fixing method according to Embodiment 10 of the present invention is shown.
[0114] The received pseudorange and carrier phase are evaluated, and navigation satellites and low-Earth orbit (LEO) satellites that simultaneously possess L-band measurements and navigation enhancement signal measurements are statistically analyzed. Using the basic navigation message, the positions (centroid positions) and clock errors of all the aforementioned navigation satellites and LEO satellites are calculated. Based on the calculated positions and clock errors of the navigation satellites and LEO satellites, high-precision orbit and clock error corrections from the received navigation enhancement message are used for correction, resulting in the precise positions (centroid positions) and precise clock error corrections of the navigation satellites and LEO satellites. Based on the calculated centroid positions of the navigation satellites and LEO satellites, the transmission positions of signals at different frequencies are further corrected. The correction method is the same for both L-band navigation signals and navigation enhancement signals of the navigation satellites and LEO satellites. The correction steps are further characterized by: for satellite S, its frequency f... q The antenna phase center from the navigation enhancement information is used to correct the signal transmission position. Based on the clock bias, the pseudorange transmission hardware delay of signals at different frequencies is further corrected.
[0115] Example 11
[0116] Figure 11 A schematic flowchart of an ambiguity fixing method according to Embodiment Eleven of the present invention is shown.
[0117] The corrections are related to satellites, mainly involving corrections for Earth's rotation, the effects of spacetime curvature, special relativity, and antenna phase winding (the correction methods mainly use mature correction models and methods); corrections are related to propagation paths, using known models and projection functions to correct tropospheric delay; and corrections are related to receivers, using known models to correct for Earth's solid tides and ocean tides.
[0118] Example 12
[0119] Figure 12 A schematic flowchart of an ambiguity fixing method according to Embodiment Twelve of the present invention is shown.
[0120] Using the received navigation enhancement signals from navigation satellites and low-Earth orbit satellites, and based on the calculated satellite positions and clock biases, a preliminary user receiver position is calculated using the known least-squares method for single-point positioning. Based on the calculated user receiver position, corrections are made for both the satellite antenna phase center variation and the user receiver antenna phase center variation. Using the corrected precise satellite positions and clock biases, and the corrected L-band observations, a combined dual-frequency ionospheric-free observation of the navigation satellites and low-Earth orbit satellites is obtained using the known dual-frequency ionospheric-free formula. Finally, using the wide-band navigation information... The decimal deviation of the lane is used to determine the ambiguity of the wide lane. The calculated dual-frequency ionosphere-free combined observation and the wide lane ambiguity are combined to obtain the narrow lane ambiguity and true range combination, including the decimal part. Since the frequency of the navigation augmentation signal is above 22.3 GHz and its landing power is high, the ionospheric influence on the pseudorange of the navigation augmentation signal is very small, and the high landing power results in a small measurement error. Using the pseudorange observation of the navigation augmentation signal and the observation obtained in step 505, the narrow lane ambiguity is rapidly fixed using a known ambiguity fixing algorithm.
[0121] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
[0122] The contents not described in detail in this specification are common knowledge to those skilled in the art.
Claims
1. A carrier phase ambiguity fast fixing system, characterized by, include: The ground-based operation and control system monitors, controls, and manages the navigation satellite constellation and the low-Earth orbit satellite constellation; Based on the received satellite status information and control and management information, various types of navigation information are generated and uploaded to navigation satellites and low-Earth orbit satellites; A navigation satellite constellation consists of multiple navigation satellites distributed across multiple medium and high orbit planes, used to broadcast medium and high orbit navigation signals to the world or specific regions. A low-Earth orbit (LEO) satellite constellation comprises multiple LEO satellites distributed across multiple LEO planes, used to broadcast LEO navigation and communication signals globally or to specific regions; the LEO and high-Earth orbit (MEO) navigation signals and LEO navigation signals each include navigation signals in at least two frequency bands. The user receiver receives communication signals broadcast by low-Earth orbit satellite constellations, as well as medium- and high-Earth orbit navigation signals broadcast by navigation satellite constellations, or low-Earth orbit navigation signals broadcast by low-Earth orbit satellite constellations, or medium- and high-Earth orbit navigation signals and low-Earth orbit navigation signals jointly broadcast by navigation satellite constellations and low-Earth orbit satellite constellations, to achieve positioning. Both the medium-to-high orbit navigation signals and the low-orbit navigation signals mentioned above include navigation signals and navigation information of their respective navigation satellites: The navigation signal includes an L-band signal and a navigation enhancement signal; the L-band signal has a frequency range of 1 to 2 GHz, the center frequency of the navigation enhancement signal is above 22.3 GHz, the main lobe bandwidth of the navigation enhancement signal exceeds 20.46 MHz, and the signal grounding power is higher than -155 dBw. The navigation information includes basic navigation information and enhanced navigation information; The basic navigation information includes broadcast ephemeris, broadcast clock bias, broadcast almanac, broadcast code phase deviation, and satellite integrity. The navigation enhancement information includes orbit clock bias correction, satellite attitude, antenna phase center and variation, hardware delay correction, and wide and narrow lane fractional deviation of L-band signals. The L-band signal broadcasts signals at two or more frequency points; The navigation enhancement signal is coherently generated with the L-band signal, and they share the same frequency reference. The method for rapidly fixing carrier phase ambiguity includes: Using the navigation enhancement signals received from navigation satellites and low-orbit satellites, as well as satellite positions and clock errors, the preliminary user receiver position is calculated based on single-point positioning using the least squares method. Based on the initial user receiver position, the changes in the satellite antenna phase center are corrected, and the changes in the user receiver antenna phase center are also corrected. Using the corrected satellite position and clock error, the L-band observations are corrected using the correction values of the observations. Using the dual-frequency ionospheric formula, the combined dual-frequency ionospheric observations of navigation satellites and low-Earth orbit satellites are obtained. The ambiguity of the wide lane is determined by utilizing the decimal deviation of the wide lane in the navigation enhancement information; Based on the dual-frequency ionosphere-free combined observation and wide-lane ambiguity, a combined observation including the fractional part of narrow-lane ambiguity and true distance is obtained; The narrow-lane ambiguity is fixed by using pseudorange observations of navigation enhancement signals and combined observations including the fractional part of the narrow-lane ambiguity and the true range.
2. A carrier phase ambiguity resolution system according to claim 1, wherein, The center frequency points of the navigation enhancement signals in the medium-high orbit navigation signals and low orbit navigation signals are determined to be the same or different according to requirements.
3. The carrier phase ambiguity fast fixing system according to claim 1, characterized in that, The user receiver achieves positioning based on the L-band signal and navigation enhancement signal in the medium-high orbit navigation signal, or based on the L-band signal and navigation enhancement signal in the low orbit navigation signal, or simultaneously based on the L-band signal and navigation enhancement signal in both the medium-high orbit navigation signal and the low orbit navigation signal.
4. A method for rapid carrier phase ambiguity fixing, implemented using a rapid carrier phase ambiguity fixing system as described in any one of claims 1 to 3, characterized in that, include: At a certain moment, the user receiver Simultaneously, it receives L-band navigation signals and navigation enhancement signals broadcast by navigation satellite constellations and low-Earth orbit satellite constellations, and generates pseudorange and carrier phase measurements of the L-band navigation signals, as well as pseudorange and carrier phase measurements of the navigation enhancement signals. The user receiver simultaneously receives The system continuously generates navigation enhancement information from navigation satellites and low-Earth orbit satellites based on measured values, and then extracts basic navigation information and navigation enhancement information respectively. Receiving navigation enhancement information includes: receiving navigation information broadcast by the navigation satellite constellation itself; receiving navigation information broadcast by the communication frequency band of the low-Earth orbit satellite constellation; and receiving navigation information broadcast by the navigation enhancement frequency band of the low-Earth orbit satellite constellation. The user receiver uses the received pseudorange and carrier phase measurements, along with the received basic navigation information and navigation enhancement information, to calculate the correction values for the navigation satellite constellation and low-Earth orbit satellite constellation observations, and executes the carrier phase ambiguity fixing method to achieve positioning.
5. The method according to claim 4, characterized in that, The corrections for the observations of the navigation satellite constellation and the low-Earth orbit satellite constellation include: generating the position and clock difference of the navigation satellite constellation and the low-Earth orbit satellite constellation at the signal transmission time based on the navigation information of the navigation satellite constellation and the low-Earth orbit satellite constellation, and calculating the corrections for the observations of the navigation satellite constellation and the low-Earth orbit satellite constellation.
6. The method according to claim 5, characterized in that, The generation of the signal transmission time based on the navigation information of the navigation satellite constellation and the low-Earth orbit satellite constellation, including the positions and clock biases of the navigation satellite constellation and the low-Earth orbit satellite constellation, includes: The received pseudorange and carrier phase measurements are evaluated, and navigation satellites and low-Earth orbit satellites that simultaneously possess L-band navigation signal measurements and navigation enhancement signal measurements are statistically analyzed. Using basic navigation information, the positions and clock biases of all navigation satellites and low-Earth orbit satellites that simultaneously possess L-band navigation signal measurements and navigation augmentation signal measurements; Based on the position and clock error, the orbit clock error correction amount in the received navigation enhancement information is used to make corrections, and the centroid position and clock error correction amount of the navigation satellite and the low-Earth orbit satellite are obtained. Correcting the transmission position of signals at different frequencies based on the centroid positions of navigation satellites and low-Earth orbit satellites: The transmission position of signals is corrected using the antenna phase center in the navigation enhancement information; The transmission hardware delay of pseudorange for signals at different frequencies is corrected based on the clock bias correction.
7. The method according to claim 4, characterized in that, The correction values for the calculated navigation satellite constellation and low-Earth orbit satellite constellation observations include: Errors related to the satellite are corrected through Earth rotation correction, spacetime curvature correction, special relativity correction, and antenna phase winding correction. Errors related to the propagation path are corrected by correcting tropospheric delay using a projection function; By correcting for Earth solid tides and ocean tides, errors related to the receiver are corrected.