Dgnss / rtk base station position bias detection and computation

Abstract

Global navigation satellite system (GNSS) receivers can provide more accurate positioning when using real-time kinematic (RTK) or differential GNSS (DGNSS) correction augmentation. The techniques described herein utilize multi-constellation multi-frequency (MCMF) measurements made at a base station at first and second times to generate correction information that can be used to detect and correct for a bias (or offset) in the base station position. This bias can be detected by a rover station, or can be detected by the base station itself.

Description

Technical Field

[0001] This invention generally relates to the field of satellite-based positioning, and more specifically, to error correction in the context of Global Navigation Satellite Systems (GNSS) to achieve more accurate position determination. Background Technology

[0002] High-accuracy positioning can provide significant value for a wide range of modern applications for mobile devices. For example, for autonomous driving applications, not only meter-level positioning is helpful in determining the vehicle's lane, but sub-meter-level positioning is also helpful in determining the vehicle's position within the lane. Consumer-grade GNSS receivers now offer high-quality carrier phase measurements with multi-constellation, multi-frequency (MCMF) capabilities. Summary of the Invention

[0003] When augmented using real-time kinematic (RTK) or differential GNSS (DGNSS) correction, Global Navigation Satellite System (GNSS) receivers can provide more accurate positioning. The techniques described herein utilize multi-constellation multi-frequency (MCMF) measurements taken at the base station at both the first and second times to generate correction information that can be used to detect and correct for deviations (or offsets) in the base station's location. These deviations can be detected by the rover station or by the base station itself. Attached Figure Description

[0004] Figure 1 This is a simplified diagram of a satellite-based differential positioning system according to an embodiment.

[0005] Figure 2-3 This is a top-down view illustration used for autonomous driving applications involving location determination.

[0006] Figure 4 This is a flowchart of an embodiment of a method for determining base station deviation.

[0007] Figure 5 The figure is a graph of the simulation results, which plots the change in the accuracy of base station offset determination over time in the manner described in this paper.

[0008] Figure 6 This is a flowchart of a method for determining the deviation in the location of a base station in a satellite-based differential positioning system, according to an embodiment.

[0009] Figure 7 This is a block diagram of the various hardware and software components of the mobile station according to an embodiment.

[0010] Figure 8 This is a block diagram of various hardware and software components of a base station according to an embodiment.

[0011] Figure 9 It is a block diagram of various hardware and software components of a computer system according to an embodiment.

[0012] According to some embodiments, similar reference numerals in the figures indicate similar elements. Additionally, multiple instances of an element can be indicated by adding a letter or hyphen after the first digit of the element followed by a second digit. For example, multiple instances of element 110 can be represented as 110-1, 110-2, 110-3, etc., or 110a, 110b, 110c, etc. When only the first digit is used to refer to such an element, it should be understood as any instance of that element (e.g., element 110 in the aforementioned examples would refer to elements 110-1, 110-2, and 110-3, or elements 110a, 110b, and 110c). Detailed Implementation

[0013] Several illustrative embodiments will now be described with reference to the accompanying drawings, which form part of this invention. While specific embodiments that may implement one or more aspects of this disclosure are described below, other embodiments and various modifications may be used without departing from the scope of this disclosure or the spirit of the appended claims.

[0014] As used herein, the terms “mobile station” and “mobile device” and their variations are generally used interchangeably. Broadly speaking, a mobile station or mobile device can include electronic devices and can be referred to as a device, mobile device, wireless device, mobile terminal, etc. Therefore, a mobile station or mobile device can correspond to a mobile phone, smartphone, laptop computer, tablet computer, personal data assistant (PDA), tracking device, wearable device, Internet of Things (IoT) device, or some other portable or mobile device. (However, it should be noted that embodiments of a mobile station are not necessarily limited to mobile applications). A mobile station can include a single entity or can include multiple entities, such as in a personal area network, where a user may employ audio, video, and / or data I / O devices and / or body sensors, as well as a separate wired or wireless modem. In some cases, a mobile station or mobile device may be part of other entities, for example, a chipset supporting a modem integrated into larger mobile entities such as vehicles, drones, packages, cargo, robotic devices, etc. In some embodiments, the mobile station or mobile device may include a mobile phone or other device that supports wireless communication under the 5G NR standard and / or one or more additional radio access technologies (RATs), such as Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long Term Evolution (LTE), High Speed ​​Packet Data (HRPD), IEEE 802.11 Wi-Fi, etc. (BT), Global Microwave Access Interoperability (WiMAX), etc. The rover or mobile device can also support wireless communication using a wireless local area network (WLAN). Furthermore, the rover or mobile device may be capable of using any or all of these wireless technologies to connect to public or private data communication networks (e.g., the Internet).

[0015] As used herein, the terms “position” and “location” are used interchangeably. Furthermore, regarding GNSS-based positioning, terms such as “position determination,” “location,” and “position estimation” are also used interchangeably herein to refer to the position estimation of a rover (or mobile device) including a GNSS receiver. The position estimation of the rover can be geodetic, providing the rover's position coordinates (e.g., latitude and longitude), which may or may not include a height component (e.g., height above sea level, height above ground level, floor level, or basement level, or depth below). In some embodiments, the coordinate frame providing the coordinates may include an East, North, Up (ENU) coordinate frame, although different coordinate frames may be used in different applications.

[0016] Furthermore, although described as being performed by a mobile station, base station (also known as a reference station), or service provider server (or similar server), the techniques for base station offset determination provided herein are not limited to these. For example, a 5G NR network may include various devices connected thereto, which are capable of determining base station offset from the base station (as described herein, for example, regarding...). Figure 4 and Figure 6 Measurement data is obtained. In this case, this determination can be forwarded (e.g., directly or indirectly via directional or broadcast signaling) to the rover and / or other equipment. Additionally or alternatively, such equipment may be able to perform some aspects of base station offset determination, while other equipment (e.g., rover) described herein performs other aspects. Furthermore, although the determination of base station offset for correcting rover positioning described herein is based on this, the application is not limited thereto. For example, applications may include determining the precise location of stationary equipment (e.g., base station), which can be used for precise positioning.

[0017] Figure 1This is a simplified diagram of a satellite-based differential positioning system 100, which can be used to provide real-time dynamic (RTK) or differential GNSS (DGNSS) correction to a rover 110, enabling the rover 110 to achieve more accurate GNSS-based positioning than conventional GNSS technologies. Specifically, the satellite-based differential positioning system 100 achieves high-accuracy GNSS positioning of the rover 110 by using GNSS receivers at both the rover 110 and base station 120. These GNSS receivers receive RF signals 130 from a satellite vehicle (SV) 140, which originates from one or more GNSS constellations (e.g., Global Positioning System (GPS), Galileo (GAL), Global Navigation Satellite System (GLONASS), BeiDou, Indian Regional Navigation Satellite System (IRNSS), Quasi-Zenith Satellite System (QZSS), etc.). As previously described, the type of rover 110 used can vary depending on the application and can include any of various types of mobile devices capable of accessing GNSS positioning data, such as mobile devices equipped with GNSS receivers.

[0018] For simplicity, Figure 1 The diagram shown illustrates only a single rover 110, base station 120, data communication network 150, service provider server 160, and three SVs 140. However, in practice, the satellite-based differential positioning system 100 may include dozens or hundreds of SVs 140, as mentioned above, which may be part of multiple GNSS constellations. Additionally or alternatively, the satellite-based differential positioning system 100 may have any number of base stations 120 (tens, hundreds, etc.). For example, some embodiments may have a large network of geographically dispersed base stations 120 communicatively coupled to the data communication network 150 and managed by a service provider. The service provider may include one or more service provider servers 160 capable of collecting information provided by the base stations 120 and transmitting that information to the rover 110. This process may include the service provider server 160 transmitting information from its associated base station 120 (e.g., the base station 120 closest to the rover 110) to the rover 110. Furthermore, the satellite-based differential positioning system 100 can serve any number of mobile stations 110 (e.g., dozens, hundreds, thousands, millions, etc.).

[0019] Data communication network 150 may include one or more public and / or private networks (e.g., the Internet) capable of transmitting data from base station 120 to mobile station 110. Arrows from mobile station 110 and base station 120 to data communication network 150 indicate communication links, which may include one or more intermediate devices and / or networks capable of relaying information to and from data communication network 150. Mobile station 110 and base station 120 may communicate with data communication network 150 using wired and / or wireless communication technologies (such as the previously listed wireless communication technologies).

[0020] To perform conventional GNSS positioning, rover 110 can use code-based positioning to determine the distance to each of SV 140 based on a delay determined in a generated pseudo-random binary sequence received in RF signal 130. The accuracy of the resulting positioning by rover 110 is affected by errors caused by SV 140 orbit and clock, ionospheric and tropospheric delays, and other phenomena. Conventional GNSS positioning provides meter-level accuracy, which may be less than ideal for many applications.

[0021] DGNSS is a differential positioning technique that determines a more accurate location for rover 110 by considering the differences in measurements performed by rover 110 and base station 120. In DGNSS, rover 110 performs code-based ranging based on RF signal 130 in a manner similar to conventional GNSS, but also uses base station 120 to perform similar measurements from a known reference location. These measurements can be used to differentially correct for errors from various sources, such as orbit and clock errors, ionospheric and tropospheric delays, etc. To this end, "service data" including the measurement results from base station 120 and the known location of the base station is provided to rover 110 for differential correction. This service data can be provided to rover 110 via, for example, a data communication network 150. DGNSS positioning can provide accuracy from meters to sub-meters.

[0022] RTK positioning offers a more accurate solution by using carrier-based ranging based on the RF signal 130 and DGNSS-like observations from a reference location using base station 120. DGNSS can be used to differentially correct errors from various error sources. However, in RTK, the service data transmitted to rover 110 further allows the rover to use differential carrier phase between the base station and the client equipment to determine highly accurate positioning. RTK positioning can provide accuracy in centimeters or decimeters.

[0023] The positioning of rover 110 (using DGNSS or RTK) depends on the known location of base station 120, which is included in the service data sent to rover 110. Therefore, any deviation (inaccuracy) in the location of base station 120 will be transferred to the deviation in the positioning of rover 110. Because the location of base station 120 is fixed, its location is typically determined during initial configuration and is conveyed as the "known location" of base station 120 in all subsequent service data related to base station 120. (In some embodiments, the location of base station 120 may be stored in a database maintained by service provider server 160.) Therefore, if the location of base station 120 is inaccurate, the positioning of all rover 110 that depends on service data from base station 120 will also be inaccurate.

[0024] Such base station deviations, if left undetected, can pose serious problems in many applications. Figure 2 This is a top-down view of such an application: autonomous driving. In this example, an autonomous vehicle 210 travels along a path 250 from a first location 230 through an intersection 220 to a second location 240. For example, Level 2 or higher autonomous driving often requires decimeter-level accuracy. Therefore, DGNSS or RTK positioning technologies can be used to determine the accurate location of vehicle 210 (as a rover 110) in real time.

[0025] However, the problem is that the service data provided to vehicle 210 includes base station offset 260. Therefore, although DGNSS or RTK positioning technologies otherwise provide accuracy to vehicle 210, the positioning of vehicle 210 is offset by base station offset 260, resulting in an estimated driving path 270 with far less accuracy than required for autonomous driving. As can be seen, due to base station offset 260 (which may be several meters in some cases), the estimated driving path 270 will place vehicle 210 in a different lane (or even off the road in other cases). Autonomous vehicles following driving path 270 for only a short distance can lead to multiple accidents.

[0026] Figure 3 Is with Figure 2 A diagram of a top view under the same conditions. However, ( Figure 2 The base station deviation 260 has been eliminated, resulting in a corrected estimated travel path 280 that is much larger than expected. Figure 2 The estimated driving path 270 is more accurate. As can be seen, by reducing or eliminating base station bias 260, the resulting positioning of the vehicle 210 using DGNSS or RTK is closer to the highly accurate positioning capabilities of DGNSS or RTK. This can be achieved at the decimeter or even centimeter level, and therefore can be used for autonomous driving and other applications.

[0027] The embodiments provided herein aim to reduce or eliminate base station deviation 260. To this end, techniques can be used to generate correction information at base station 120 using multi-constellation, multi-frequency (MCMF) measurements performed at base station 120 at first and second times. This correction information can identify deviations in the location of base station 120, for example, at the decimeter level. Different techniques can be employed to detect and (optionally) correct deviations. According to some embodiments, such detection and / or correction can be performed in real time.

[0028] Figure 4 This is a flowchart of an embodiment of a method for determining base station deviation, wherein the functions are mathematically described. Figure 4 The functionality of each of the blocks shown can be performed by hardware and / or software components of a computing device, such as the hardware and / or software components of mobile station 110, base station 120, or service provider server 160. (Described below) Figure 7-9 Example hardware and software components for example computing devices are provided. It should be noted that, although... Figure 4 The embodiments described herein include specific terminology and equations, but alternative embodiments may use alternatives and / or equations in a similar manner.

[0029] At block 410, the initial base station measurement value at the start time (t0) is obtained. As described above, this function can be performed by mobile station 110, base station 120, or service provider server 160 (or other computing device). Because this measurement is determined during the normal process of acquiring and providing service data, mobile station 110 (which receives the measurement in the service data), base station 120 (which determines the measurement), or service provider server 160 (which can relay service data with the measurement to mobile station 110) can easily obtain this information.

[0030] As shown in block 410, the measurement at the initial time (t0) can be expressed as:

[0031] The variables in the equation are defined as follows:

[0032] -Single difference operator between satellites

[0033] Φ IF - Ionospheric carrier phase combination (e.g., combinations of GPS L1, L2 and L5 carriers; GAL E1, E5A, E5B and E6 carriers; and / or BDS B1I, B1C, B2A, B2B and B3 carriers).

[0034] ρ - calculated geometric distance

[0035] LOS - Satellite Line of Sight Vector

[0036] dX - The position error vector to be estimated

[0037] Trop - Tropospheric Delay Calculated Using Model

[0038] MAP - Tropospheric Moisture Component Mapping Function

[0039] Wet - Tropospheric wet zenith delay error to be estimated

[0040] The combined error of Sat satellite orbit and clock

[0041] Ambiguity term of N-deionized carrier phase combination.

[0042] In this embodiment, ionospheric error does not need to be considered in equation (1) because it can be reduced using the ionospheric cancellation function of the MCMF GNSS receiver. More specifically, ionospheric refraction occurs when a GNSS signal passes through the ionosphere. However, the first-order effect (99.9%) of the error caused by this refraction is inversely proportional to the square of the signal frequency. Therefore, this first-order effect can be eliminated in the MCMF receiver when at least two signals from the same satellite at different frequencies are available, which can be achieved by using a combination of signals, namely, an ionospheric carrier phase combination (Φ). IF These signals are detected by measurements. (Similar ionosphere desaturation combinations are also applicable to pseudorange measurements). In this way, the MCMF GNSS receiver can detect multiple RF signals 130 (e.g., GPS L1 and L5 frequencies, GAL E1 and E5A frequencies, BDS B1I and B2A frequencies, etc.) transmitted at different frequencies (e.g., GPS L1 and L5 frequencies, GAL E1 and E5A frequencies, BDS B1I and B2A frequencies, etc.). Figure 1 Measurements are performed (as shown), taking into account ionospheric delay. That is, alternative embodiments can use receivers that do not provide ionospheric observations in this regard, and ionospheric-related errors can be accounted for by estimating the ionospheric delay at the start time t0 and subsequent times ti.

[0043] At block 420, a GNSS correction term corresponding to the start time (t0) is determined. As will be seen, this can be applied to subsequent measurements to provide correction and determine deviations in base station locations. The correction term can be calculated as follows:

[0044]

[0045] As shown in block 420, this correction term can also be expressed as:

[0046]

[0047] At block 430, the base station measurement for the "current time" (ti) can be obtained in a similar manner to that obtained at block 410. This measurement can be represented as:

[0048]

[0049] Then, by taking the difference between the terms in equations (3) and (4), the correction can be applied to the measurement of 430 blocks. Because and The result measurement at the current time ti, after applying correction, can be expressed as follows:

[0050]

[0051]

[0052] However, because the location of base station 120 did not change, dX ti =dX t0 Therefore, equation (5) can be simplified to:

[0053]

[0054] like Figure 4 Block 440 is shown.

[0055] With this correction term in equation (6), an extended Kalman filter (EKF) (or a similar filter) can be used by solving dX. t0 To accurately estimate base station bias.

[0056] Figure 4 The processing shown can be performed in real time, with the determinations at blocks 420 and 440 performed by a positioning engine (e.g., an EKF-based or other filter-based positioning engine, such as weighted least squares (WLS), a hatch filter, a particle filter, etc., performed by the mobile station 110, base station 120, or service provider server 160). The length of time between the start time (t0) and the current time (ti) used to obtain an accurate estimate of the base station offset can vary depending on the required functionality.

[0057] For example, Figure 5This is a graph of the simulation results, where the accuracy of the base station deviation estimation components (north error 510, east error 520, and top error 530) is plotted over time. The simulation lasted 3600 seconds (60 minutes). It can be seen that the accuracy, particularly the horizontal accuracy, improves over time, initially exceeding 2 meters, eventually decreasing around 900 seconds (15 minutes) and remaining below 50 centimeters. Therefore, according to some embodiments, measurements obtained at block 430 can exceed 900 seconds (e.g., 20 minutes, 25 minutes, 30 minutes, etc.) to help ensure accurate base station deviation determination. In applications where accuracy is less critical, embodiments can use shorter time periods (e.g., 15 minutes, 12 minutes, etc.). Therefore, the embodiments provided herein can be used to detect and optionally correct base station deviations using only GNSS measurements taken at base station 120. These deviations can be reduced from several meters to less than 1 meter (e.g., a few decimeters, or even a few centimeters). As mentioned above, this is particularly useful in applications requiring a high level of accuracy, such as autonomous driving (e.g., as...). Figure 2 and Figure 3 (As shown).

[0058] Different actions can be taken after a base station deviation is determined, and these actions may depend on the application. For example, in some applications requiring meter-level accuracy or higher, the detected base station deviation on the decimeter scale can be negligible. Therefore, the base station deviation can be compared to a threshold to determine whether to take action, where the threshold is determined based on the application. Alternatively, some applications may require the highest possible accuracy, and therefore, action can be taken if any deviation is detected. (e.g.) Figure 5 As shown, an accuracy can be determined by a minimum deviation, and therefore, the detected deviation can be compared to this minimum accuracy. For example, in high-accuracy applications such as RTK positioning, action can be taken if any deviation exceeding 50 cm is detected. For DGNSS positioning, action can be taken if a deviation exceeding 1 m is detected. Alternative embodiments and / or applications may have different deviation thresholds.

[0059] According to some embodiments, a notification can be sent when a base station deviation is detected to exceed a minimum threshold. That is, the device estimating the base station deviation (e.g., mobile station 110, service provider server 160, or base station 120) can notify other devices. For example, mobile station 110 can notify a mobile data provider or other location provider, which can forward this notification to other mobile stations 110 and / or otherwise prevent other mobile stations from determining their location based on information from base station 120 with the detected deviation. Additionally or alternatively, the device estimating the base station deviation can notify a service provider (e.g., via service provider server 160) allowing the service provider to take corrective measurements to eliminate the deviation. (One such corrective measurement may include, for example, using...) Figure 4 (Method for calculating base station deviation).

[0060] In some embodiments, the estimated base station offset (dX) t0 This can be used for correction. That is, mobile station 110 can use base station offsets (which may have been calculated or received from another mobile station, base station 120, or service provider server 160) to correct the location of mobile station 110 based on service data including the base station offsets. Furthermore, the base station offsets (along with the identifier of base station 120) can be provided to mobile data providers or other location providers and propagated to other mobile stations to similarly compensate for the base station offsets. Additionally or alternatively, service provider server 160 can use the base station offsets to correct the stored value of the "known location" of base station 120, thereby ensuring that subsequent service data provided to mobile stations from base station 120 has the corrected known location of base station 120.

[0061] Figure 6 This is a flowchart of a method 600 for determining the deviation in the location of a base station in a satellite-based differential positioning system according to an embodiment. Method 600 can use the techniques described above and can therefore be considered as... Figure 4 The previously described process is illustrated in the embodiment shown. Alternative embodiments may be combined, separated, or otherwise modified. Figure 6 The functions described in the block shown may vary functionally. According to some embodiments, in Figure 6 The functions described in the block shown can be performed by mobile station 110, base station 120, or service provider server 160. Therefore, for execution... Figure 6 The components of the functionality of one or more blocks shown may include Figure 7-9 The hardware and / or software components shown in the hardware block diagram are described in detail below.

[0062] At block 610, the function includes obtaining a first GNSS measurement determined by a GNSS receiver at a first time, wherein the first GNSS measurement includes an ionospheric carrier phase combination. The ionospheric carrier phase combination may take the form of equation (1). To obtain the ionospheric carrier phase combination, the measurement may be performed by an MCMF receiver at the base station. As shown at block 420 and described above, the ionospheric carrier phase combination may be used to create a correction term (e.g., denoted as equation (2) or (3)). That is, it should be noted that the correction term may not be generated explicitly. Rather, it may be generated implicitly when at least some portions of the ionospheric carrier phase combination determined at the first time are used to differentially correct the ionospheric carrier phase combination determined at a subsequent time. In some embodiments, the ionospheric carrier phase combination may be included in or derived from service data transmitted partly from the base station to the mobile station.

[0063] If the function at block 610 is performed by mobile station 110, the components used to perform that function may include the bus 705 of mobile station 110, processing unit 710, wireless communication interface 730, memory 760, and / or other software and / or hardware components, such as Figure 6 As shown in the diagram. If the function at block 610 is performed by base station 120, the components used to perform that function may include base station 120's bus 805, processing unit 810, GNSS receiver 870, memory 860, and / or other software and / or hardware components, such as... Figure 8 As shown in the diagram. Finally, if the function at block 610 is performed by the service provider server 160 or other computer system, the components used to perform that function may include the base station 120's bus 905, processing unit 910, communication subsystem 930, working memory 935, application 945, and / or other software and / or hardware components, such as... Figure 9 As shown in the figure.

[0064] In block 620, the function includes obtaining a second GNSS measurement determined by the base station's GNSS receiver at a second time, wherein the second GNSS measurement includes a carrier phase combination that de-ionizes the sphere. As indicated by the embodiments described above, the length of the time between determining the first GNSS measurement and determining the second GNSS measurement can depend on the desired functional variations. In some embodiments, this time may be 15 minutes or longer.

[0065] If the function at block 620 is performed by mobile station 110, the components used to perform that function may include the bus 705 of mobile station 110, processing unit 710, wireless communication interface 730, memory 760, and / or other software and / or hardware components, such as Figure 6As shown in the diagram. If the function at block 620 is performed by base station 120, the components used to perform that function may include base station 120's bus 805, processing unit 810, GNSS receiver 870, memory 860, and / or other software and / or hardware components, such as... Figure 8 As shown in the diagram. Finally, if the function at block 620 is performed by the service provider server 160 or other computer system, the components used to perform that function may include the base station 120's bus 905, processing unit 910, communication subsystem 930, working memory 935, application 945, and / or other software and / or hardware components, such as Figure 9 As shown in the figure.

[0066] The functionality at block 630 includes determining the deviation in the base station location based at least in part on the difference between the first GNSS measurement and the second GNSS measurement. (As with...) Figure 4 As discussed above, this determination can be made by taking the difference between like terms in the first and second ionospheric carrier-free phase combinations, which can be further simplified by equalizing the base station deviation measured at the first time with the base station deviation measured at the second time, as shown in equation (6) above. In some embodiments, as previously indicated, additional correction terms may be applied. For example, in some embodiments, inter-satellite single differences may be performed to obtain one or more correction terms for one or more errors of the first GNSS measurement, the second GNSS measurement, or both, which are related to receiver clock, inter-frequency / intra-frequency and constellation deviations of GNSS, or receiver phase center variation effects, or any combination thereof. The deviation in the location of the base station can then be determined at least in part based on one or more correction terms.

[0067] If the function at block 630 is performed by mobile station 110, the components used to perform that function may include the bus 705 of mobile station 110, processing unit 710, memory 760, and / or other software and / or hardware components, such as Figure 6 As shown in the diagram. If the function at block 630 is performed by base station 120, the components used to perform that function may include base station 120's bus 805, processing unit 810, memory 860, and / or other software and / or hardware components, such as... Figure 8 As shown in the diagram. Finally, if the function at block 630 is performed by the service provider server 160 or other computer system, the components used to perform that function may include the base station 120's bus 905, processing unit 910, working memory 935, application 945, and / or other software and / or hardware components, such as... Figure 9 As shown in the figure.

[0068] As described above, embodiments may have additional attributes based on the required functionality. As described above, the method can be performed by a base station, rover, or server (e.g., a computer server or other computer system). Base station deviations can be used for positioning correction. Therefore, in some embodiments, method 600 may include adjusting the rover's GNSS positioning at least in part based on determined base station position deviations, wherein the rover's GNSS positioning is based on service data from the base station. As described above, the service data from the base station may include measurements from the base station (including first and / or second GNSS measurements determined at blocks 610 and / or 620), and the base station's known location. In some embodiments, this location may be obtained by a service provider, which can create service data for the rover by retrieving measurements from the base station, obtaining the corresponding known location of the base station, and sending the measurements and known location as service data to the rover. Depending on the required functionality, the service data may include RTK service data or DGNSS service data.

[0069] Because method 600 can be performed by a base station, mobile station, or server (e.g., by a computer system), embodiments may additionally include providing information indicating the determined deviation to another device. This can be done, for example, via direct communication (e.g., the mobile station communicating directly with the base station) and / or indirect communication (e.g., the mobile station or base station communicating with a service provider server via the Internet). The information indicating the determined deviation may include the determined deviation itself, or may include information derived from the deviation, such as the corrected position of the base station.

[0070] In embodiments where method 600 is performed by a server, the server can be operated by different types of entities. According to some embodiments, the server can be operated by, for example, a manufacturer of the mobile station, a provider of RTK services (which may also operate base station 120), a wireless operator, or a third party (e.g., a provider of crowdsourcing, navigation, and / or internet services). Additionally or alternatively, multiple servers can be configured to perform operations jointly or individually. Figure 6 One or more blocks are shown, and / or a determined deviation in the base station location is received from another device (e.g., another server, base station, mobile station, etc.).

[0071] Figure 7 This is a block diagram of various hardware and software components of the mobile station 110 according to an embodiment. These components may be as described above herein (e.g., with...). Figure 1-6 (Related) Use. For example, mobile station 110 can perform... Figure 1 The mobile station 110 shown in the image Figure 2 and Figure 3 Vehicle 210 shown in the image Figure 4 and Figure 6Methods and / or similar functions. It should be noted that... Figure 7 This is intended only to provide a general description of the various components; any or all of the components may be used appropriately. As previously stated, the rover 110 can vary in form and function and may ultimately include any GNSS-enabled equipment, including vehicles, commercial and consumer electronic devices, survey equipment, etc. Therefore, in some cases, Figure 7 The components shown can be located in a single physical device and / or distributed across a variety of networked devices that can be positioned in different physical locations (e.g., different locations within a vehicle).

[0072] Mobile station 110 is shown as including hardware elements electrically coupled (or otherwise communicable, as applicable) via bus 705. The hardware elements may include processing unit 710, which may include, but is not limited to, one or more general-purpose processors, one or more special-purpose processors (such as digital signal processing (DSP) chips, graphics acceleration units (GPUs), application-specific integrated circuits (ASICs), and / or similar), and / or other processing structures or components. Figure 7 As shown, some embodiments may have a separate digital signal processor (DSP) 720, depending on the required functionality. Location determination and / or other determinations based on wireless communication may be provided in the processing unit 710 and / or the wireless communication interface 730 (discussed below). The rover 110 may also include one or more input devices 770, which may include, but are not limited to, a keyboard, touchscreen, touchpad, microphone, buttons, dials, switches, and / or the like; and one or more output devices 715, which may include, but are not limited to, a display, light-emitting diodes (LEDs), speakers, and / or the like. As will be understood, the types of input devices 770 and output devices 715 may depend on the type of rover 110 in which the input devices 770 and output devices 715 are integrated.

[0073] Mobile station 110 may also include wireless communication interface 730, which may include, but is not limited to, modem, network card, infrared communication device, wireless communication device, and / or chipset (e.g., Equipment, IEEE 702.11 equipment, IEEE 702.15.4 equipment, Wi-Fi equipment, WiMAX TM Equipment, wide area network (WAN) equipment and / or various cellular equipment, etc.) and / or similar equipment, which enables the mobile station 110 to access the above-mentioned... Figure 1The network communication described herein. Wireless communication interface 730 may allow communication (e.g., sending and receiving) of data and signaling with the network, for example, via a WAN access point, cellular base station and / or other access node type and / or other network components, computer system and / or any other electronic device described herein. Communication may be performed via one or more wireless communication antennas 732 that transmit and / or receive wireless signals 734. Antenna 732 may include one or more discrete antennas, one or more antenna arrays, or any combination thereof.

[0074] Depending on the required functionality, the wireless communication interface 730 may include a separate transceiver, a separate receiver and transmitter, or any combination of transceivers, transmitters and / or receivers to communicate with base stations and other ground transceivers, such as wireless devices and access points. As previously described, the rover 110 can communicate with different data networks, which can include various network types, as can be achieved through the wireless communication interface 730. For example, a wireless wide area network (WWAN) may be a CDMA network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single Carrier Frequency Division Multiple Access (SC-FDMA) network, or a WiMAX network. TM (IEEE 702.16) networks, etc. CDMA networks can implement one or more Radio Access Technologies (RATs), such as... WCDMA, etc. Cdma2000 includes IS-95, IS-2000, and / or IS-856 standards. TDMA networks can implement GSM, Digital Advanced Mobile Telephone Systems (D-AMPS), or some other RATs. OFDMA networks can adopt LTE. TM LTE Advanced, 5G NR, etc. 5G NR, LTE, LTE Advanced, GSM, and WCDMA are among the technologies used in the 3GPP (3rd Generation Partnership Project). TM As described in the document. Described in documents from an alliance known as "3rd Generation Partnership Project 2" (3GPP2). 3GPP TM The 3GPP2 documentation is publicly available. WLAN can also be an IEEE 702.11x network, and Wireless Personal Area Networks (WPANs) can be... Networks, IEEE 702.15x, or other types of networks. The techniques described herein can also be used in any combination of WWAN, WLAN, and / or WPAN.

[0075] The rover 110 may also include sensors 740. Sensors 740 may include, but are not limited to, one or more inertial sensors and / or other sensors (e.g., accelerometers, gyroscopes, cameras, magnetometers, altimeters, microphones, proximity sensors, light sensors, barometers, etc.), some of which may be used to supplement and / or facilitate the positioning of the rover 110 as described herein.

[0076] Embodiments of rover 110 may also include a GNSS receiver 780 capable of receiving signals 784 from one or more GNSS satellites (e.g., SV 140) using antenna 782 (which may be identical to antenna 732) as described herein. As previously described, the GNSS receiver 780 can use GNSS SVs from one or more GNSS constellations (e.g., Figure 1 The RF signal of the GNSS receiver 140 (SV 140) and DGNSS and / or RTK service data provided by a DGNSS / RTK service provider are measured to determine the location of the rover 110. In some embodiments, the GNSS receiver 780 may include an MCMF receiver. Furthermore, the GNSS receiver 780 may be used with various augmentation systems (e.g., SBAS) that may be associated with or otherwise enabled by one or more global and / or regional navigation satellite systems, such as Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlap Service (EGNOS), Multifunctional Satellite Augmentation System (MSAS), and Geographic Augmentation Navigation System (GAGAN), and / or similar systems.

[0077] The mobile station 110 may also include a memory 760 and / or communicate with the memory 760. The memory 760 may include machine- or computer-readable media, which may include, but is not limited to, local and / or network-accessible memory, disk drives, drive arrays, optical storage devices, solid-state storage devices such as random access memory (RAM), and / or read-only memory (ROM), which may be programmable, flash-updatable, and / or similar. Such a storage device may be configured to implement any suitable data storage, including but not limited to various file systems, database structures, and / or similar.

[0078] The memory 760 of the mobile station 110 may also include software elements (in Figure 7(Not shown in the text) includes an operating system, device drivers, executable libraries, and / or other code, such as one or more applications, which may include computer programs provided by various embodiments, and / or may be designed to implement the methods provided by other embodiments described herein, and / or configure the systems provided by other embodiments described herein. By way of example only, one or more processes described with respect to the methods discussed above may be implemented as code and / or instructions in memory 760, which may be executed by rover 110 (and / or processing unit 710 or DSP 720 within rover 110). In one aspect, such code and / or instructions may be used to configure and / or adjust a general-purpose computer (or other device) to perform one or more operations according to the described methods.

[0079] Figure 8 This is a block diagram of various hardware and software components of a base station 800 according to an embodiment, which may be as described above herein (e.g., in conjunction with...). Figure 1-7 ) is used. For example, base station 120 can perform Figure 1 The operation of base station 120 shown in the figure Figure 4 and Figure 6 The method, and / or similar functionality. It should be noted that... Figure 8 This is intended only to provide a general description of the various components; any or all of the components may be used appropriately.

[0080] Base station 800 is shown to include hardware elements electrically coupled (or otherwise communicable, as applicable) via bus 805. The hardware elements may include processing unit 810, which may include, but is not limited to, one or more general-purpose processors, one or more special-purpose processors (such as DSP chips, graphics accelerator processors, ASICs, and / or similar), and / or other processing structures or components. Figure 8 As shown, some embodiments may have a separate DSP 820, depending on the required functionality. According to some embodiments, location determination and / or other determinations based on wireless communication may be provided in the processing unit 810 and / or the wireless communication interface 830 (discussed below). The base station 800 may also include one or more input devices, which may include, but are not limited to, a keyboard, display, mouse, microphone, buttons, dials, switches, and / or the like; and one or more output devices, which may include, but are not limited to, a display, light-emitting diodes (LEDs), speakers, and / or the like.

[0081] The base station also includes a GNSS receiver 870, which is capable of using antenna 884 to measure signals 882 received from one or more GNSS satellites (e.g., SV140) to obtain an ionospheric carrier phase combination, as described herein (e.g., in...). Figure 4 Blocks 410 and 430 and / or Figure 6 (Measurements performed by blocks 610 and 620). Therefore, GNSS receiver 870 may include an MCMF receiver. As previously described, this measurement information may be included as part of service data (e.g., RTK and / or DGNSS service data) sent to rover 110 by a service provider. Thus, base station 120 may provide this data to a service provider, which may include the measurement data along with the base station's known location in the service data sent to rover 110.

[0082] Base station 800 may also include network interface 880, which may include support for wireless and / or wired communication technologies. Network interface 880 may include a modem, network interface card (NIC), chipset, and / or the like. Depending on the required functionality, network interface 730 may include a separate transceiver, a separate receiver and transmitter, or any combination of transceivers, transmitters, and / or receivers, which may be coupled to one or more input and / or output communication interfaces to allow data exchange with a network (e.g., data communication network 150), a communication network server, a computer system, and / or any other electronic device described herein. Therefore, this can include a variety of wireless technologies (e.g., such as...). Figure 7 The wireless communication interface 730 described herein and / or any of the wired technologies.

[0083] In many embodiments, base station 800 will also include memory 860. Memory 860 may include, but is not limited to, local and / or network-accessible memory, disk drives, drive arrays, optical storage devices, solid-state storage devices such as RAM, and / or ROM, which may be programmable, flash-updatable, and / or similar. Such storage devices may be configured to implement any suitable data storage, including but not limited to various file systems, database structures, and / or similar.

[0084] The memory 860 of base station 800 may also include software elements (in...) Figure 8 (Not shown in the text) includes an operating system, device drivers, executable libraries, and / or other code, such as one or more applications, which may include computer programs provided by various embodiments, and / or may be designed to implement the methods provided by other embodiments described herein, and / or configure the systems provided by other embodiments described herein. By way of example only, one or more processes described with respect to the methods discussed above may be implemented as code and / or instructions in memory 860, which may be executed by base station 800 (and / or processing unit 810 or DSP 820 within base station 800). In one aspect, such code and / or instructions may be used to configure and / or adjust a general-purpose computer (or other device) to perform one or more operations according to the described methods.

[0085] It can be noted that, although Figure 8 GNSS receiver 780 and Figure 8 The 870 shown is depicted as a component distinct from other components within rover 110 or base station 120, but embodiments are not limited thereto. As used herein, the term "GNSS receiver" may include hardware and / or software components configured to acquire GNSS measurements (measurements from GNSS satellites). Thus, in some embodiments, a GNSS receiver may include a measurement engine (as software) executed by one or more processing units, such as processing unit 710 or 810, DSP 720 or 820, and / or a processing unit within wireless communication interface 730 (e.g., in a modem). A GNSS receiver may also optionally include a positioning engine, such as those described herein, which can determine the location of the GNSS receiver using GNSS measurements from the measurement engine. The positioning engine may also be executed by one or more processing units, such as processing unit 710 or 810, DSP 720 or 820.

[0086] Figure 9 This is a block diagram of an embodiment of computer system 900, which can be used, in whole or in part, to provide the functionality of service provider server 160 and / or other computer systems described herein. It should be noted that... Figure 9 This is intended only to provide a general description of the various components; any or all of the components may be used appropriately. Therefore, Figure 9 This broadly illustrates how the various system elements are implemented in a relatively separate or relatively more integrated manner. Additionally, it can be noted that... Figure 9 The components shown can be located in a single device and / or distributed across a variety of networked devices that can be located in different geographical locations.

[0087] Computer system 900 is shown as including hardware elements electrically coupled (or otherwise communicable, as applicable) via bus 905. The hardware elements may include processing units 910, which may include, but are not limited to, one or more general-purpose processors, one or more special-purpose processors (e.g., digital signal processing chips, graphics accelerators, and / or similar), and / or other processing architectures, which may be configured to perform one or more methods described herein. Computer system 900 may also include one or more input devices 915, which may include, but are not limited to, a mouse, keyboard, camera, microphone, and / or similar; and one or more output devices 920, which may include, but are not limited to, display devices, printers, and / or similar.

[0088] The computer system 900 may also include (and communicate with) one or more non-transitory storage devices 925, which may include, but are not limited to, local and / or network-accessible memory, and / or may include, but are not limited to, disk drives, drive arrays, optical storage devices, solid-state storage devices such as random access memory (RAM), and / or read-only memory (ROM), which may be programmable, flash-updatable, and / or similar. Such storage devices may be configured to implement any suitable data storage, including but not limited to various file systems, database structures, and / or similar. Such data storage may include databases and / or other data structures for storing and managing information and / or other information, as described herein, transmitted via a hub to one or more devices.

[0089] Computer system 900 may also include communication interface 930, which may include software components configured for wireless or wired technologies. Wired technologies may include Ethernet, coaxial communication, Universal Serial Bus (USB), etc. Wireless communication may include 5G, LTE, and / or previous technologies (e.g., in combination with...). Figure 7 The communication subsystem 930 may include any other wireless technology described in the wireless communication interface 730. Therefore, the communication subsystem 930 may include a modem, network interface card (wireless or wired), infrared communication device, wireless communication device and / or chipset, and / or similar, which may have separate transceivers, separate receivers and transmitters, or any combination of transceivers, transmitters and / or receivers, enabling the computer system 900 to communicate with any device on any or all of the communication networks described herein (e.g., data communication network 150), including mobile station 110, base station 120, other computer systems and / or any other electronic devices described herein. Therefore, the communication subsystem 930 can be used to receive and transmit data as described in the embodiments herein.

[0090] In many embodiments, the computer system 900 will also include working memory 935, which may include RAM or ROM devices as described above. Software elements shown to reside within working memory 935 may include operating system 940, device drivers, executable libraries, and / or other code, such as one or more applications 945, which may include computer programs provided by various embodiments, and / or may be designed to implement the methods provided by other embodiments described herein, and / or configure the systems provided by other embodiments described herein. By way of example only, one or more processes described with respect to the methods discussed above may be implemented as code and / or instructions executable by a computer (and / or processing units within a computer); in one aspect, such code and / or instructions may be used to configure and / or adjust a general-purpose computer (or other device) to perform one or more operations according to the described methods.

[0091] These instructions and / or code sets may be stored on a non-transitory computer-readable storage medium, such as storage device 925 described above. In some cases, the storage medium may be incorporated into a computer system, such as computer system 900. In other embodiments, the storage medium may be separable from the computer system (e.g., a removable medium, such as an optical disc), and / or provided in an installation package, such that the storage medium can be used to program, configure, and / or adapt a general-purpose computer with the instructions / code stored thereon. These instructions may take the form of executable code executable by computer system 900, and / or may take the form of source code and / or installable code, which, when compiled and / or installed on computer system 900 (e.g., using any of a variety of generally available compilers, installers, compression / decompression tools, etc.), takes the form of executable code.

[0092] It will be apparent to those skilled in the art that substantial modifications can be made to suit specific requirements. For example, custom hardware and / or specific elements implemented in hardware, software (including portable software such as applets), or both can be used. Furthermore, connectivity with other computing devices (such as network input / output devices) can be employed.

[0093] Referring to the accompanying drawings, components that may include memory may include non-transitory machine-readable media. As used herein, the terms "machine-readable media" and "computer-readable media" refer to any storage medium that participates in providing data that causes a machine to operate in a particular manner. In the embodiments provided above, various machine-readable media may relate to providing instructions / code to a processing unit and / or other devices for execution. Additionally or alternatively, machine-readable media may be used to store and / or carry such instructions / code. In many embodiments, a computer-readable medium is a physical and / or tangible storage medium. Such media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Common forms of computer-readable media include, for example, magnetic and / or optical media, any other physical media with a perforated pattern, RAM, programmable ROM (PROM), erasable PROM (EPROM), FLASH-EPROM, any other memory chip or memory cartridge, a carrier wave as described below, or any other medium from which a computer can read instructions and / or code.

[0094] The methods, systems, and apparatuses discussed herein are examples. Various processes or components may be appropriately omitted, substituted, or added in various embodiments. For example, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of embodiments may be combined in a similar manner. The various components in the figures provided herein may be implemented in hardware and / or software. Furthermore, technology is constantly evolving, and therefore many elements are examples, and the scope of disclosure is not limited to these specific examples.

[0095] It has been shown that it is sometimes convenient, primarily for common reasons, to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerals, or similar terms. However, it should be understood that all such terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless otherwise specifically stated, it will be understood from the foregoing discussion that the use of terms such as “processing,” “calculation,” “determine,” “generate,” “identify,” “associate,” “measure,” “execute,” or similar terms in this specification refers to the action or processing of a specific device, such as a dedicated computer or similar dedicated electronic computing device. Therefore, in the context of this specification, a dedicated computer or similar dedicated electronic computing device or system capable of manipulating or converting signals, generally referred to as physical electronic, electrical, or magnetic quantities within the memory, registers, or other information storage, transmission, or display devices of the dedicated computer or similar dedicated electronic computing device or system.

[0096] The terms “and” and “or” as used herein can include a variety of meanings, and are expected to depend, at least in part, on the context in which they are used. Generally, “or” when used with an associative list, such as A, B, or C, is intended to mean A, B, and C, here in the sense of inclusion, and A, B, or C, here in the sense of exclusivity. Additionally, the term “one or more” as used herein can be used to describe any feature, structure, or property of the singular, or can be used to describe some combination of features, structures, or properties. However, it should be noted that this is merely an illustrative example, and the subject matter is not limited to this example. Furthermore, the term “at least one” when used with an associative list, such as A, B, or C, can be interpreted as referring to any combination of A, B, and / or C, such as A, AB, AA, AAB, AABBCCC, etc.

[0097] Following the description of several embodiments, various modifications, alternative structures, and equivalents may be used without departing from the spirit of this disclosure. For example, the foregoing elements may be merely components of a larger system, where other rules may take precedence over or otherwise modify the application of various embodiments. Furthermore, steps may be taken before, during, or after considering the foregoing elements. Therefore, the above description does not limit the scope of this disclosure.

Claims

1. A method for determining the positional deviation of a base station in a satellite-based differential positioning system, the method comprising: Obtain a first Global Navigation Satellite System (GNSS) measurement, wherein the first GNSS measurement is determined by a GNSS receiver at the base station at a first time, and wherein the first GNSS measurement includes an ionospheric carrier phase combination; A second GNSS measurement is obtained, the second GNSS measurement being determined by the GNSS receiver of the base station at the base station at a second time, wherein the second GNSS measurement includes an ionospheric carrier phase combination; as well as The deviation of the location of the base station is determined at least in part based on the difference between the first GNSS measurement and the second GNSS measurement.

2. The method of claim 1, further comprising providing information indicating the deviation of the location of the base station to the base station, mobile station, or server, wherein the information indicating the deviation of the location of the base station includes: The deviation of the location of the base station, The corrected position of the base station based on the deviation of the base station's position. Or both.

3. The method of claim 1, further comprising: Perform inter-satellite single difference to obtain one or more correction terms for one or more errors of the first GNSS measurement, the second GNSS measurement, or both, said one or more errors being related to receiver clock, GNSS inter-frequency / intra-frequency and constellation offset, or receiver phase center variation effect or any combination thereof; The deviation of the location of the base station is determined at least in part based on the one or more correction terms.

4. The method of claim 1, wherein the method is performed by the base station, mobile station, or computer server.

5. The method of claim 1, wherein the time length between determining the first GNSS measurement and determining the second GNSS measurement is 15 minutes or longer.

6. The method of claim 1, further comprising: The GNSS positioning of the rover is adjusted at least in part based on the deviation of the determined location of the base station, wherein the GNSS positioning of the rover is based on service data from the base station.

7. The method of claim 1, wherein the satellite-based differential positioning system is configured to send service data associated with the base station to one or more rover stations, the service data including the first GNSS measurement and the second GNSS measurement.

8. The method of claim 7, wherein the service data includes RTK service data or DGNSS service data.

9. An apparatus comprising: transceiver; At least one memory containing instructions; as well as One or more processing units, the one or more processing units being configured to execute the instructions to cause the device to: Obtain a first Global Navigation Satellite System (GNSS) measurement, wherein the first GNSS measurement is determined by a GNSS receiver at a base station at a first time, and wherein the first GNSS measurement includes an ionospheric carrier phase combination; A second GNSS measurement is obtained, the second GNSS measurement being determined by the GNSS receiver of the base station at the base station at a second time, wherein the second GNSS measurement includes an ionospheric carrier phase combination; and The deviation of the base station's location is determined at least in part based on the difference between the first GNSS measurement and the second GNSS measurement.

10. The apparatus of claim 9, wherein the one or more communication-coupled processing units are further configured to provide information indicating the deviation of the location of the base station to the base station, mobile station, or computer server, wherein the information indicating the deviation of the location of the base station includes: The deviation of the location of the base station, The corrected position of the base station based on the deviation of the base station's position. Or both.

11. The device of claim 9, wherein the one or more processing units that are communicatively coupled are further configured to: Perform inter-satellite single difference to obtain one or more correction terms for one or more errors of the first GNSS measurement, the second GNSS measurement, or both, said one or more errors being related to receiver clock, GNSS inter-frequency / intra-frequency and constellation offset, or receiver phase center variation effect or any combination thereof; The deviation of the location of the base station is determined at least in part based on the one or more correction terms.

12. The device of claim 9, wherein the device includes the base station, mobile station, or computer server.

13. The device of claim 9, wherein the one or more communicationally coupled processing units are further configured to: obtain the first GNSS measurement and the second GNSS measurement such that the time length between determining the first GNSS measurement and determining the second GNSS measurement is 15 minutes or longer.

14. The apparatus of claim 9, wherein the one or more processing units that are communicatively coupled are further configured to: adjust the GNSS positioning of the rover station at least in part based on a deviation of the determined location of the base station, wherein the GNSS positioning of the rover station is based on service data from the base station.

15. An apparatus comprising: Components for obtaining first global navigation satellite system, GNSS, measurements, wherein the first GNSS measurement is determined by a GNSS receiver at a base station at a first time, and wherein the first GNSS measurement includes an ionospheric carrier phase combination; Components for obtaining a second GNSS measurement, the second GNSS measurement being determined by the GNSS receiver of the base station at the base station at a second time, wherein the second GNSS measurement includes an ionospheric carrier phase combination; as well as A component for determining the deviation of the base station's location based at least in part on the difference between the first GNSS measurement and the second GNSS measurement.

16. The apparatus of claim 15, further comprising: A component for providing information indicating the deviation of the location of the base station to the base station, mobile station, or computer server, wherein the information indicating the deviation of the location of the base station includes: The deviation of the location of the base station, The corrected position of the base station based on the deviation of the base station's position. Or both.

17. The apparatus of claim 15, further comprising: Components for performing inter-satellite single differences to obtain one or more correction terms for one or more errors of the first GNSS measurement, the second GNSS measurement, or both, said one or more errors being related to receiver clock, GNSS inter-frequency / intra-frequency and constellation offset, or receiver phase center variation effect, or any combination thereof; The deviation of the location of the base station is determined at least in part based on the one or more correction terms.

18. The apparatus of claim 15, wherein the apparatus includes the base station, mobile station, or computer server.

19. The apparatus of claim 15, further comprising: A component used to ensure that the time length between determining the first GNSS measurement and determining the second GNSS measurement is 15 minutes or longer.

20. The apparatus of claim 15, further comprising: Components for adjusting the GNSS positioning of a rover station based at least in part on a deviation from the determined location of the base station, wherein the GNSS positioning of the rover station is based on service data from the base station.

21. A non-transitory computer-readable medium having instructions embedded therein, which, when executed by one or more processing units, cause the one or more processing units to perform the method of any one of claims 1-8.

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