阅读说明：本技术 用于对装置进行定位的方法和定位装置 (Method for positioning a device and positioning device ) 是由 侯坤穗 于 2018-08-10 设计创作，主要内容包括：一种用于对装置进行定位的方法和定位装置,此方法包含：接收对应在全球导航卫星系统中的至少五个卫星的卫星信号；从至少这些卫星信号的五个导航数据判别这些卫星信号中是否有任何卫星信号有错误比特边沿；以及于判别出这些卫星信号中有卫星信号有错误比特边沿的情况下,从这些卫星信号中找出错误卫星信号,且使用其他卫星信号的导航数据来得到装置的位置。(A method for locating a device and a locating device, the method comprising: receiving satellite signals corresponding to at least five satellites in a global navigation satellite system; judging whether any satellite signal in the satellite signals has an error bit edge from at least five navigation data of the satellite signals; and under the condition that the satellite signals are judged to have error bit edges, finding out the error satellite signals from the satellite signals, and obtaining the position of the device by using navigation data of other satellite signals.)

1. A method for locating a device, comprising:

receiving satellite signals corresponding to at least five satellites in a global navigation satellite system;

judging whether any satellite signal in the satellite signals has an error bit edge from at least navigation data of the satellite signals; and

and under the condition that the satellite signal has an error bit edge, finding out an error satellite signal from the satellite signal, and obtaining the position of the device by using navigation data of other satellite signals.

2. The method of claim 1, wherein determining whether any of the satellite signals has an erroneous bit edge comprises:

performing an iterative operation on the navigation data through a position of the device and a least squares estimate of a time displacement between the gnss and the device to obtain a residual error of the satellite signal; and

comparing a largest of the residuals to a predetermined residual threshold;

and if the maximum residual error is larger than the preset residual error threshold value, judging that the satellite signal has an error bit edge.

3. The method of claim 2, wherein the iterative operation is stopped if the sum of the residuals is less than a predetermined residual threshold sum.

4. The method of claim 1, wherein the satellite signals correspond to five satellites each.

5. The method of claim 4, wherein finding a faulty satellite signal from the satellite signals comprises:

calculating navigation data of all combinations of four selected satellite signals in the satellite signals to respectively obtain related residual residuals of the selected satellite signals and a residual satellite signal in the satellite signals; and

and judging the residual satellite signal corresponding to the minimum of the related residual residuals as the error satellite signal.

6. The method of claim 1, wherein the navigation data of the satellite signals is transmitted via the device to an entity connected to the device.

7. The method of claim 1, wherein the gnss is a gps or a glonass system.

8. A positioning device, comprising:

an antenna for receiving satellite signals corresponding to at least five satellites in a global navigation satellite system;

a processor configured to perform the following operations:

judging whether any satellite signal in the satellite signals has an error bit edge from at least navigation data of the satellite signals; and

and under the condition that the satellite signal is judged to have the error bit edge, finding out an error satellite signal from the satellite signal, and obtaining the position of the positioning device by using navigation data of other satellite signals.

9. The positioning device as claimed in claim 8, wherein in the operation of determining whether any of the satellite signals has an erroneous bit edge, the processor is configured to:

performing an iterative operation on the navigation data through a position of the positioning device and a least squares estimation of a time displacement between the global navigation satellite system and the positioning device to obtain a residual error of the satellite signal; and

comparing a largest of the residuals to a predetermined residual threshold;

and if the maximum residual error is larger than the preset residual error threshold value, judging that the satellite signal has an error bit edge.

10. A non-transitory computer readable medium storing computer program instructions that, when executed by a processor, cause the processor to:

respectively obtaining navigation data of satellite signals from satellite signals corresponding to at least five satellites in a global navigation satellite system;

determining from at least the navigation data whether any of the satellite signals has an erroneous bit edge; and

and under the condition that the satellite signal has an error bit edge, finding out an error satellite signal from the satellite signal, and obtaining the position of the device by using navigation data of other satellite signals.

Technical Field

The present disclosure relates to the field of positioning technology, and more particularly, to a method for positioning a device, a positioning device and a non-transitory computer readable medium.

Background

A Global Navigation Satellite System (GNSS) is a satellite-based system for providing navigation data so that a receiving end can obtain position information (such as longitude, latitude, altitude, etc.) on the earth according to the navigation data. On the other hand, in response to the needs of life, many electronic products, such as mobile phones, car navigation devices, smartwatches, cameras, etc., have a positioning function, so that the user can obtain the location information, and the service provider can provide the location-based service to the user in real time based on the location information provided by the user. However, in an environment such as a weak satellite signal, a wrong position information may be obtained due to a bit synchronization error of the navigation data.

The prior art can solve this phenomenon by using a Fault Detection and Exclusion Algorithm (Fault Detection and Exclusion Algorithm) under the condition of more than five localizable satellite signals. However, in the case of exactly five localizable satellite signals, no available solution has been proposed.

Disclosure of Invention

The main objective of the present disclosure is to provide a mechanism for determining an erroneous satellite signal from received satellite signals, wherein after determining that one of the received satellite signals has an erroneous bit edge, the satellite signal having the erroneous bit edge can be ignored, and navigation data of other satellite signals is used to perform an actual positioning coordinate calculation. The positioning can be done correctly because the satellite signals with erroneous bit edges ensure that the actual positioning coordinate calculation of the device is not involved.

One embodiment of the present disclosure is a method for positioning a device, the method comprising: receiving satellite signals corresponding to at least five satellites in a Global Navigation Satellite System (GNSS); determining whether any of the satellite signals has an error bit edge (bit edge) from navigation data of at least the satellite signals; and under the condition that the satellite signals are judged to have error bit edges, finding out an error satellite signal from the satellite signals, and obtaining the position of the device by using navigation data of other satellite signals.

In one embodiment, determining whether any of the satellite signals has an erroneous bit edge comprises: iteratively calculating the navigation data by the position of the device and the least square estimation of the time displacement between the device and the global navigation satellite system to obtain the residual error (residual) of the satellite signals; and comparing the largest of the residuals to a predetermined residual threshold. If the maximum residual error is larger than the preset residual error threshold value, judging that the satellite signal has an error bit edge.

In one embodiment, if the sum of the residuals is less than the predetermined residual threshold sum, the iteration is stopped.

In one embodiment, the satellite signals correspond to five satellites respectively.

In one embodiment, the step of finding a faulty satellite signal from the satellite signals comprises: calculating navigation data of all combinations of four selected satellite signals in the satellite signals, firstly obtaining solutions of time displacement and positions of the selected satellite signal equations, and substituting the solutions into residual satellite signal equations in the satellite signals to calculate relevant residual residuals; and judging the residual satellite signal corresponding to the minimum of the relevant residual residuals as an error satellite signal.

In one embodiment, the navigation data of the satellite signals is transmitted via the device to an entity connected to the device.

In one embodiment, the GNSS is a Global Positioning System (GPS) or Glonass (GLONASS) system.

Another embodiment of the present disclosure is a positioning device that includes an antenna and a processor. The antenna is used for receiving satellite signals corresponding to at least five satellites in the global navigation satellite system. The processor is configured to perform the following operations: determining whether any of the satellite signals has an erroneous bit edge from navigation data of at least the satellite signals; and under the condition that the satellite signals are judged to have error bit edges, finding out the error satellite signals from the satellite signals, and obtaining the position of the positioning device by using navigation data of other satellite signals.

In one embodiment, in determining whether any of the satellite signals has an erroneous bit edge, the processor is configured to: iterative operation is carried out on the navigation data through the position of the positioning device and the least square estimation of the time displacement between the global navigation satellite system and the positioning device, so as to obtain the residual error of the satellite signals; and comparing the largest of the residuals to a predetermined residual threshold. If the maximum of the residuals is larger than the predetermined residual threshold, it is determined that there is an error bit edge in the satellite signal.

Yet another embodiment of the disclosure is a non-transitory computer readable medium storing computer program instructions that, when executed by a processor, cause the processor to: obtaining navigation data of satellite signals from satellite signals corresponding to at least five satellites in a global navigation satellite system, respectively; determining from at least the navigation data whether any of the satellite signals has an erroneous bit edge; and under the condition that the satellite signals are judged to have error bit edges, finding out the error satellite signals from the satellite signals, and obtaining the position of the device by using navigation data of other satellite signals.

In summary, the present disclosure can ensure that the satellite signals with wrong bit edges do not involve in the calculation of the actual positioning coordinates, so that the positioning can be completed correctly. In addition, according to the disclosure, even if there is a satellite signal with an error bit edge, the satellite signal with the error bit edge can be found according to the navigation data of the satellite signals, and the navigation data of other satellite signals is used to perform the actual positioning coordinate calculation, so that the actual positioning coordinate calculation does not need to be performed until the received satellite signals are all correct, and the positioning process can be completed more quickly.

Drawings

For a more complete understanding of the embodiments and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an example of a positioning device and a satellite of a global navigation satellite system according to some embodiments of the present disclosure;

FIG. 2 is a schematic view of a positioning device according to some embodiments of the present disclosure;

FIG. 3 is a flow chart of a method of positioning a device according to some embodiments of the present disclosure;

FIG. 4 is a flow chart of a step in the method of FIG. 3; and

fig. 5 is a flow chart of another step in the method of fig. 3.

Detailed Description

Embodiments of the present disclosure are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative and do not limit the scope of the disclosure.

As used herein, the term "coupled" may refer to two or more elements being in direct physical or electrical contact with each other or in indirect physical or electrical contact with each other. Coupled may also mean that two or more elements are in operation or act on each other.

It is to be understood that, although the terms first, second, …, etc. may be used herein to describe various signals and/or entities, these signals and/or entities should not be limited by these terms. These terms are only used to distinguish one signal and/or entity from another signal and/or entity.

The methods described in this disclosure may be implemented by various means, for example, in hardware, firmware, software, or a combination thereof. For a hardware implementation, the methods may be implemented on one or more general-purpose processors, Central Processing Units (CPUs), microprocessors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, controllers, microcontrollers, specific hardware components, or a combination thereof.

FIG. 1 shows a positioning device 100 and a GNSS satellite SV according to some embodiments of the present disclosure₁～SV_NExamples of (2). The Global Navigation Satellite System may be a Global Positioning System (GPS), a Glonass (GLONASS) System, a Galileo Positioning System (Galileo Positioning System), a Beidou Navigation Satellite System (BeiDou Navigation Satellite System), a Quasi-Zenith Satellite System (QZSS), an Indian Regional Navigation Satellite System (IRNSS), or other systems that provide satellites to the Positioning device 100A system of signals.

The positioning device 100 can receive satellite signals directly and/or indirectly from the global navigation satellite system and then perform a positioning process based on the received satellite signals to obtain its positioning coordinates. In some embodiments, the positioning device 100 is a global navigation satellite system receiver, which receives satellite signals from visible (visible) satellites and performs positioning coordinate calculation according to navigation data obtained from the received satellite signals. For example, if there are six satellites visible to the positioning device 100, the positioning device 100 uses the navigation data of the six satellites to calculate its positioning coordinates.

According to various implementations, the positioning device 100 may be software-based, hardware-based, or both software and hardware-based. For example, the positioning device 100 may be a mobile entity such as a mobile phone, a tablet computer, a car recorder, a smart watch, or a module in the mobile device, or a non-transitory computer readable medium storing computer program instructions executed by a processor.

Fig. 2 is a schematic diagram of a positioning device 200 according to some embodiments of the present disclosure. The positioning apparatus 200 may be one of the implementations of the positioning apparatus 100 of fig. 1 or other entities or modules for positioning. The positioning device 200 is used for receiving satellite signals from a global navigation satellite system and performing positioning operations based on the received satellite signals, and may also be referred to as a global navigation satellite system receiver.

The positioning device 200 is hardware-based and includes an antenna 210, a front-end circuit 220, and a processor 230. The antenna 210 is used to receive satellite signals in analog format. The signal reception frequency band of the antenna 210 may be related to its type, configuration, size, pattern, and/or other factors. In the case of the global positioning system, the kind, structure, size, and pattern of the antenna 210 may be designed such that the antenna 210 has a reception band having a reception center frequency of approximately 1575.42GHz (center frequency of the L1 band), 1227.60GHz (center frequency of the L2 band), or 1167.45GHz (center frequency of the L5 band). The front-end circuit 220 is used for converting the satellite signals into digital format for the processor 230 to obtain (extract and decode) navigation data from the satellite signals. The front-end circuit 220 includes components such as a low noise amplifier for amplifying the satellite signal, a down-converter for down-converting the satellite signal from a radio frequency to an intermediate frequency, and an analog-to-digital converter for analog-to-digital converting the satellite signal. The front-end circuit 220 may transmit the satellite signal to the processor 230 via a wired interface or a network.

The processor 230 is configured to acquire navigation data from the satellite signals, track the satellite signals, and perform operations on the navigation data to obtain the position (i.e., positioning coordinates) of the positioning device 200 based on the navigation data. In other embodiments, operations such as acquiring navigation data from satellite signals, tracking satellite signals, and performing operations on navigation data may be performed in different processors or modules, respectively.

Fig. 3 is a flow chart of a method 300 of locating a device according to some embodiments of the present disclosure. In the following description of the steps of the method 300, the device may be the positioning device 100 of fig. 1, the positioning device 200 of fig. 2, or other device capable of receiving satellite signals broadcast by satellites in the global navigation satellite system, and the processing of the navigation data may be performed in the device, or in other computers, servers, or other data processing-capable entities connected to the device (e.g., coupled, communicatively coupled, or otherwise connected directly or indirectly), that is, the device transmits the navigation data to the entity connected thereto, and the entity performs the operation on the navigation data. For example, if the method 300 is performed in the positioning apparatus 200, the antenna 210 is used for receiving satellite signals, the front-end circuit 220 converts the satellite signals into a digital format, and the processor 230 is used for obtaining navigation data from the satellite signals and performing operation processing on the navigation data.

The method 300 begins with step S310. In step S310, the device receives a satellite signal of a global navigation satellite system. The device may obtain navigation data from the satellite signals if the received satellite signals have at least a strength that is at least the reception sensitivity of the device.

When the apparatus obtains the navigation data from more than five satellite signals, the method 300 proceeds to step S320, and determines whether one of the obtained satellite signals has an error bit edge (bit) from the navigation data of the satellite signals. In some embodiments, for the warm start (warm start) example, the device may further use valid data such as recently decoded almanac (almanac) data and Coordinated Universal Time (UTC) to determine whether there is a satellite signal with an erroneous bit edge in the resulting satellite signal.

In some embodiments, as shown in fig. 4, the step S320 of determining whether one of the obtained satellite signals has an error bit edge includes the sub-steps SS322 and SS 324. In sub-step SS322, the navigation data is iteratively operated by least squares estimation (least squares) of the position of the device and the time displacement (offset) between the global navigation satellite system and the device to obtain a residual (residual) of the satellite signals. For convenience of illustration, in the following embodiments, the apparatus obtains M satellite signals from M satellites (M is greater than or equal to 5) of the gnss, and these M satellites are referred to as the first to mth satellites, respectively. It should be noted that the order of the above satellites does not represent the satellite numbers of the global navigation satellite system. The mth satellite has (M is a positive integer from 1 to M) a virtual distance (pseudo range) of

PR[m]＝ρ[m]+cdt-ctb[m]， (1)

Wherein

As the geometric distance between the mth satellite and the device, (x, y, z) as the three-dimensional location coordinates of the device, (S)_x[m],S_y[m],S_z[m]) Is the three-dimensional positioning coordinate of the mth satellite, c is the speed of light, dt is the time displacement between the global navigation satellite system and the device, and tb [ m [ ]]A pseudo random noise code (PRN code) phase time shift of the mth satellite is provided in the navigation data.

Taking the global positioning system as an example, the global positioning system information (hereinafter referred to as GPS information) includes five subframes (subframes), and each subframe includes 300 bits. All satellites in the global positioning system are synchronized with the global positioning system time. In addition, all GPS satellites transmit the first bit of the first subframe at the same time, and this time is appended in the time of week (TOW) field of the first subframe. In the first subframe, each bit takes 20 ms, i.e. the xth bit of the first subframe is transmitted at the value of the week time field plus x times 20 ms. At the receiving end of the global positioning system, by recording the receiving time of the xth bit of the GPS information of the mth satellite and knowing when the bit is transmitted from the mth satellite from the content of the GPS information, the traveling time of the satellite signal from the global positioning system satellite to the receiving end of the global positioning system can be calculated and the virtual distance PR m can be obtained.

By linearizing equation (1) and then performing an iterative operation, at the (i +1) th step of the iterative operation, the first order linear equation of the m-th satellite becomes

Wherein

(x_i,y_i,z_i) For the estimated position of the device at step (i +1) of the iterative operation, Δ x_i＝x_i+1-x_i，Δy_i＝y_i+1-y_i，Δz_i＝z_i+1-z_i，Δdt_i＝dt_i+1-dt_iAnd x is₀、y₀、z₀And dt₀Is an initial estimation value before the iterative operation. In the example of cold start (coldstart), the initial estimate x₀、y₀、z₀And dt₀Can be set to all 0. In contrast, in the example of warm start, the initial estimate x₀、y₀、z₀And dt₀Can be set according to the latest positioning operation to accelerate the speed of the current positioning operation.

The least squares estimate of the device position and the time displacement between the gnss and the device can be obtained from the equation Ha ═ b in the form of a matrix, where the m-th column of the matrix H(corresponding to the mth satellite) at step (i +1) of the iterative operation is

The mth column of matrix b is PR [ m ] at the (i +1) th step of the iterative operation]+ctb[m]-ρ[m]_iAnd the matrix a is a at the (i +1) th step of the iterative operation_i＝[Δx_iΔy_iΔz_icΔdt_i]^T. In the example where M is greater than or equal to 4, the only solution of the least squares estimate of equation Ha ═ b at step (i +1) of the iterative operation is (Δ x)_i,Δy_i,Δz_i,cΔdt_i) And the estimated value is (x) at the (i +1) th step of the iterative operation_i+1,y_i+1,z_i+1,cdt_i+1)＝(x_i,y_i,z_i,cdt_i)+(Δx_i,Δy_i,Δz_i,cΔdt_i). The middle residual of the mth satellite is | h at the (i +1) th step of the iterative operation_ma_i-(PR[m]+ctb[m]-ρ[m]_i) L wherein

If the sum of the intermediate residuals corresponding to the 1 st to Mth satellites is smaller than the preset intermediate residual threshold value in the Kth iteration, the iteration operation is stopped in the Kth step. The predetermined intermediate residual threshold may be set, for example, according to specification requirements. In some embodiments, the predetermined intermediate residual threshold may be set to 10 for positioning accuracy and fast positioning considerations^-3。

After an iterative operation on the navigation data (i.e. after the K-th step of the iterative operation), an estimated value (x) is obtained_K,y_K,z_K,cdt_K) And the final residual of the mth satellite R m]Is composed of

R[m]＝|PR[m]-ρ[m]_K-cdt_K+ctb[m]|。

After residual errors R1-R M of the 1 st to Mth satellites are obtained, sub-step SS324 is performed to compare the largest residual error (defined as the largest residual error RS _ MAX) among the residual errors R1-R M with a predetermined residual error threshold. If the maximum residual RS _ MAX is greater than the predetermined residual threshold, the apparatus determines that one of the satellite signals has an erroneous bit edge. In some embodiments, the predetermined residual threshold may be set to 8000 meters, depending on, for example, specification requirements.

When it is determined that one of the satellite signals has an error bit edge, the method 300 proceeds to step S330, where an error satellite signal is found from the satellite signals, and the navigation data of the other satellite signals (excluding the error satellite signal) is used to obtain the position of the device.

The detailed description of step S330 is as follows. First, as shown in fig. 5, the step S330 of finding out the wrong satellite signal among the satellite signals includes the sub-steps SS332 and SS 334. Specifically, sub-step SS332 is a calculation of navigation data for all combinations of selected ones of the satellite signals to obtain correlated residual remainders (correlated residual remainders) between the selected satellite signals and the remaining satellite signals for all combinations. For example, if the number M of received satellite signals is 5, in the combination of the satellite signals of the second to fifth satellites and the satellite signal of the first satellite remaining, the positioning coordinates of the device and the time displacement between the gnss and the device corresponding to the combination can be obtained from equation (1) where M is 2 to 5 (i.e., each selected satellite signal). By repeating the calculation of the positioning coordinates for the other combinations, five positioning coordinates and time displacements respectively corresponding to all the combinations can be obtained.

The correlated residual (corrected residual) is the residual of the remaining satellite signals substituted into the solution of the selected set of satellite signal equations. In particular, the correlation residual of a selected satellite signal of a satellite (excluding the nth satellite) relative to a combination of residual satellite signals of the nth satellite

Is defined as

Wherein

The positioning coordinates of the device are obtained for the set of equations of the satellite corresponding to the selected satellite signal (excluding the nth satellite), and

the time displacement between the global navigation satellite system and the device is obtained for the set of equations for the satellite corresponding to the selected satellite signal (excluding the nth satellite).

By calculating the related residual errors of all the combinations, the related residual errors of all the combinations can be obtained

Since the cycle of the pseudo-random noise code is one millisecond, the virtual distance errors caused by the error bit edges are all c multiplied by 10^-3Is non-zero times of the number of the associated residuals if the associated residuals are not zero

Is approximately c x 10^-3If the integer is not zero multiple, the residual satellite signal corresponding to the relevant residual error is judged to have error bit edge. For example, if the residuals are correlated

About c × 10^-3Is a non-zero multiple of an integer but other associated residual

If not, the corresponding correlation residual is determined

Has an erroneous bit edge, i.e. a corresponding correlation residual is determined

The satellite signal of the first satellite of (a) is a false satellite signal.

For example, in some embodiments, phasesResidual error

Respectively converted into the related residual remainders by

Where round (·) is the nearest integer function. Then, the sub-step SS334 is performed to determine whether the remaining satellite signal corresponding to the minimum of the residuals of the correlation residuals is an erroneous satellite signal. In particular, in the case of a liquid,minimum value of

And a predetermined threshold value

And (6) comparing. If the minimum value

Less than a predetermined threshold

Then the corresponding minimum value can be identified

Has erroneous bit edges. Predetermined threshold value

May be set to 200 or other values that facilitate distinguishing between satellite signals with erroneous bit edges and other satellite signals with correct bit edges.

It should be noted that the above-mentioned determination of whether the satellite signal has an erroneous bit edge is an example, and those skilled in the art can derive other variations according to the above-mentioned examples to achieve the same purpose. Accordingly, any variations derived from the above examples are intended to be within the scope of the present disclosure.

After determining that one of the obtained satellite signals has an erroneous bit edge, the satellite signal having the erroneous bit edge can be ignored, and navigation data of other satellite signals is used to perform the actual positioning coordinate calculation. The positioning can be done correctly because the satellite signals with erroneous bit edges ensure that the actual positioning coordinate calculation is not involved. In addition, for the embodiment of the present disclosure, the positioning process can be performed as long as five satellite signals are obtained, and even if there is an error bit edge in a satellite signal, the satellite signal with the error bit edge can be found according to the navigation data of the satellite signals and the navigation data of other satellite signals is used to perform the actual positioning coordinate calculation, and it is not necessary to perform the actual positioning coordinate calculation until the received satellite signals are all correct, so the positioning process can be completed more quickly.

In addition, when more than one of the obtained satellite signals has an error bit edge, the selected satellite signal equation set excluding the nth satellite uses at least one satellite signal with an error bit edge, and the obtained solution of time displacement and position has a large error, so that the solution is substituted into the nth satellite signal equation to calculate the residue of the correlation residual

Usually will not pass through

Checking. That is, when more than one satellite signal has an error bit edge, although all the satellite signals having the error bit edge cannot be determined, the aforementioned technique can usually determine that the positioning cannot be correctly performed at this time.

Particular implementations of the aforementioned positioning apparatus 100 or method 300 may be software and/or hardware. For example, if speed and accuracy are important considerations, hardware (e.g., a processor or a digital control chip) is essentially selected to implement the positioning apparatus 100 or method 300. The processor may be a central processing unit, microprocessor, or other hardware unit that can execute instructions. In contrast, if flexibility is a primary consideration, software is basically chosen to implement the positioning apparatus 100 or the method 300. For example, the positioning device 100 may be configured in a dispatch management tool of a non-transitory computer readable medium, and the method 300 may be programmed as computer program instructions executable by a processor and stored in a non-transitory computer readable medium accessible by the processor. The non-transitory computer readable medium may be a read-only memory, a flash memory, a floppy disk, a hard disk, an optical disk, a Universal Serial Bus (USB) flash drive, a magnetic tape, a database accessible over the internet, or other computer readable media as will be apparent to one of ordinary skill in the art. Alternatively, a combination of software and hardware may be employed to implement the positioning apparatus 100 or method 300. One of ordinary skill in the art will be able to select a software, hardware, or combination thereof based on actual needs.

Although the present disclosure has been described with reference to the above embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure, and therefore, the scope of the disclosure is to be defined by the appended claims.

Description of the symbols

100. 200 positioning device

210 antenna

220 front-end circuit

230 processor

300 method

S310, S320, S330

SS322, SS324, SS332, SS334 substeps

SV₁～SV_NAnd (4) a satellite.