A satellite navigation segmented integral Doppler velocity measurement method and system under carrier rotation

Abstract

The present invention adopts a method based on carrier phase differential speed measurement, and proposes a satellite navigation segmented integral Doppler speed measurement method and system under carrier rotation. On the basis of carrier smoothed pseudorange, the segmented integral Doppler method is used to advance estimate the Doppler measurement value at the measurement time, and the Doppler measurement value of each satellite is advanced estimated. The logic of the method used for the advance estimation is unique. While ensuring good positioning accuracy, the method eliminates the delay caused by the average differential speed measurement method, improves the real-time performance of the speed measurement, solves the problem of being unable to obtain the accurate receiver position and speed at the measurement time, and meets the demand for accurate speed measurement under carrier rotation.

Description

Technical Field

[0001] The invention relates to the field of satellite navigation, and in particular provides a satellite navigation segmented integral Doppler velocity measurement method and system under carrier rotation. Background Art

[0002] GNSS is the abbreviation of Global Navigation Satellite System, which is a global satellite navigation system. With the development of satellite navigation and positioning technology, the BeiDou Navigation Satellite System (BDS) has not only played a vital role in the military field, but also made significant contributions in the civilian field, and has gradually penetrated into various sectors of the national economy. In the military field, satellite navigation systems are widely used in high-precision navigation and positioning of various fighters, warships, combat vehicles, guided bombs and individual soldiers, and also provide a unified time reference for military equipment and combat command. In the civilian field, core industries such as communications, finance, electricity, telecommunications, and aviation have a strong dependence on satellite navigation systems. For example, satellite navigation systems can better meet the high-precision timing requirements of power systems and are now widely used in the power industry.

[0003] The positioning, navigation and timing services provided by satellite navigation systems have irreplaceable advantages in terms of service scope, service performance, service popularity and flexibility, and are therefore widely used in the measurement of moving carrier speed. There are four main methods for satellite navigation speed measurement: position differential speed measurement, raw Doppler speed measurement, raw pseudorange differential speed measurement, and carrier phase differential speed measurement.

[0004] (1) Position differential speed measurement:

[0005] Using the starting epoch and end epoch The position vector and , find the current Carrier speed at the moment :

[0006] (1)

[0007] In the above formula is the position update time interval, and the speed at time t calculated at this time Obviously The average speed during the time period, When it approaches 0 infinitely, That is The instantaneous speed at the moment. From the formula, it can be seen that the position differential speed measurement is greatly affected by the positioning accuracy and positioning frequency.

[0008] (2) Raw Doppler velocity measurement:

[0009] The receiver pseudorange observation equation is as follows:

[0010] (2)

[0011] Where n=1,2,…,N is the number of the satellite measurement value. is the pseudorange, is the geometric distance, is the receiver clock error, is the satellite clock error, is the ionospheric error, is the tropospheric error, is the pseudorange measurement error noise term.

[0012] The derivative of formula (2) with respect to time is:

[0013] (3)

[0014] in, is the pseudorange rate, is the rate of change of the geometric distance between the receiver and the satellite, is the receiver clock frequency drift, is the satellite clock frequency drift. Because the ionosphere change rate and the troposphere change rate are very small, they are directly ignored in formula (3), or equivalently regarded as the error term Absorption. The geometric distance change rate It can also be expressed as:

[0015] (4)

[0016] in, is the speed of the satellite, and the satellite position and speed at this time can be calculated through the ephemeris and time. is the unit vector from the satellite to the receiver. is the receiver velocity being solved.

[0017] Raw Doppler measurements , which can generally be obtained in real time through the phase-locked loop tracked by the receiver. The relationship between Doppler and pseudorange rate is as follows:

[0018] (5)

[0019] Substituting formula (3) directly into formula (2) yields:

[0020] (6)

[0021] Among them, the two unknown quantities on the left side of the equal sign are and , except for The rest are known quantities. is the wavelength. Then the variance of the matrix formed by N star observations is as follows:

[0022] (7)

[0023] in , the matrix G is the geometric matrix of the unit observation vector.

[0024] Finally, the receiver velocity can be calculated using the least squares method using at least 4 satellite observations. and receiver clock frequency drift .

[0025] The original Doppler speed measurement is greatly affected by the original Doppler values ​​output by different receivers. Generally, the speed measurement error can reach more than 0.5m / s under static conditions. It is rarely used in general receivers.

[0026] (3) Original pseudo-range differential velocity measurement:

[0027] The original pseudo-range differential velocity measurement mainly uses the original pseudo-range of the receiver to perform differential to obtain the pseudo-range rate, as shown below:

[0028] (8)

[0029] The subscripts k and k-1 represent adjacent measurement epochs. The original pseudo-range differential velocity measurement replaces formula (5) with formula (8). The remaining steps are the same as the original Doppler velocity measurement. The receiver velocity can be obtained by least squares. and receiver clock frequency drift .

[0030] Raw pseudorange differential speed measurement is generally not used for receiver speed measurement because the raw pseudorange measurement values ​​are relatively rough.

[0031] (4) Carrier phase differential speed measurement

[0032] Carrier phase differential velocity measurement mainly uses the integrated Doppler measurement value to perform differential to obtain the pseudo-range rate, as shown below:

[0033] (9)

[0034] The subscripts k and k-1 represent adjacent measurement epochs. Carrier phase differential velocity measurement replaces equation (5) with equation (9). The remaining steps are consistent with the original Doppler velocity measurement. The receiver velocity can be obtained by least squares. and receiver clock frequency drift .

[0035] Carrier phase differential speed measurement is the most commonly used method for receiver speed measurement because of its high carrier accuracy. Generally, the carrier smoothed pseudorange method is used to obtain the smoothed pseudorange for speed measurement.

[0036] In summary, the receiver speed measurement is mainly carried out by the above four methods. Different speed measurement methods have their own advantages and disadvantages, and can be flexibly selected according to different scenarios.

[0037] However, this method and device still have some potential disadvantages:

[0038] There are four main methods to achieve receiver speed measurement: position differential speed measurement, original Doppler speed measurement, original pseudorange differential speed measurement, and carrier phase differential speed measurement, three of which use differential speed measurement. Differential speed measurement is essentially to subtract adjacent epochs to obtain the observed value, and the actual speed is obtained. The average is to average the epochs before the speed measurement moment and the epochs after the speed measurement moment, so the current differential speed measurement methods will bring a certain speed measurement delay. Speed ​​measurement delay may cause a certain deviation between the receiver position and speed at the current moment and the actual measurement moment, especially when the receiver is in a dynamic motion environment. The greater the receiver dynamics, the greater the position and speed deviation will be. When applied in a satellite-inertial combined system, this effect is particularly important, because the inertial navigation needs to obtain the real-time position and speed of the carrier. If the satellite navigation measurement delay is too large, the deviation between the real-time position and speed of the carrier and the position and speed at the measurement moment will increase, which may cause the satellite-inertial combined navigation to fail or enter a pure inertial navigation state. Therefore, the satellite-inertial combined system will put forward certain requirements for the receiver measurement delay according to the actual application scenario.

[0039] The original Doppler speed measurement is affected by the real-time phase and frequency detection of the loop, which will have certain fluctuations and poor speed measurement accuracy. It is rarely used by general receivers. Unless it is in a special environment or the carrier has frequent cycle jumps, the original Doppler speed measurement may be used.

[0040] In addition, to solve the above problems, a method based on carrier phase difference is generally used to measure speed. The carrier phase is used to obtain the average Doppler frequency shift between two epochs through the first-order central difference method. Its essence is the central difference approximation method, which is based on the Taylor series expansion to perform Doppler estimation. Given the linear equation and step value ,So exist The Taylor series of the moment is as follows:

[0041] (10)

[0042] Same reason exist The Taylor series of the moment is as follows:

[0043] (11)

[0044] From formula (10) and formula (11), we can get:

[0045] (12)

[0046] Since the third-order change of the carrier phase is very small and can be ignored, the last two terms of the above formula can be ignored, and the Doppler frequency shift of the first-order center difference of the carrier phase can be obtained as:

[0047] (13)

[0048] in and Respectively Moment and The carrier phase at time is the epoch interval time for carrier phase calculation. From formula (13), it can be seen that the Doppler frequency shift at the measurement time is the Doppler frequency shift at the observation time obtained by averaging the carrier phase change amount before the measurement time and the carrier phase change amount after the measurement time. This average estimation method will bring a certain delay to the measurement. Summary of the invention

[0049] In order to solve one or several problems in the prior art, the present invention adopts a method based on carrier phase differential speed measurement, and proposes a satellite navigation segmented integral Doppler speed measurement method and system under carrier rotation. While ensuring good positioning accuracy, the delay caused by the average differential speed measurement method is eliminated, the real-time performance of the speed measurement is improved, and the problem of being unable to obtain the accurate receiver position and speed at the measurement time is solved. The demand for accurate speed measurement under carrier rotation is met, and the method can be applied to special applications, general aviation, unmanned aerial vehicles and other fields.

[0050] The present invention proposes a satellite navigation segmented integral Doppler speed measurement method and system under carrier rotation. On the basis of carrier smoothed pseudorange, the Doppler is segmentedly integrated to obtain multi-segment integrated Doppler, the pseudorange is obtained by an advance estimation method, and finally the least square method is used to measure the speed using the observations of multiple satellites.

[0051] In order to achieve the above-mentioned object of the invention, the method of the present invention is specifically implemented as follows (eg Figure 1 shown):

[0052] S1: poll all channels of baseband operation to determine whether the channel is valid. If not, traverse the next channel until all channels are traversed. If the channel is valid, set the carrier phase, pseudorange and pseudorange rate of the channel to invalid, and enter S2;

[0053] S2: Obtain all observations of the channel, including carrier phase observations and pseudorange observations;

[0054] S3: Calculate the original pseudorange and carrier phase respectively;

[0055] S4: Perform carrier phase difference between epochs to obtain segmented integrated Doppler, and store them sequentially with the channel as the index;

[0056] S5: Use the piecewise integral Doppler estimation algorithm to estimate the Doppler at the current measurement time in real time and convert it into a pseudorange rate. The conversion relationship between Doppler and pseudorange rate is shown in formula (5): ; Using the carrier phase, the carrier smoothing pseudorange method is adopted to calculate the smoothed pseudorange.

[0057] S6: The carrier phase, smoothed pseudorange, and pseudorange rate obtained through the above processing are sent to the positioning solution module. When the number of satellites sent is greater than or equal to 4, the position, speed, and time of the receiver can be calculated using the least square solution. The number of satellites and the number of channels are in a one-to-one correspondence, that is, one channel tracks one satellite.

[0058] In S2, the carrier phase related observations are the latched carrier integer count and carrier fractional phase, which together constitute the complete carrier phase. The pseudorange related observations are five items: message frame count, message bit count, message bit millisecond count, millisecond chip count, and code phase count;

[0059] In S3, the calculation of carrier phase is mainly to use the original pseudo-range to initialize the distance value that conforms to the physical meaning, and then use the carrier difference between epochs to calculate it. The original calculation is mainly to subtract the signal transmission time synthesized by the five count values ​​of the pseudo-range from the local time.

[0060] In S5, the segmented integrated Doppler values ​​sequentially stored in S4 are obtained to perform Doppler estimation at the current measurement moment. , , They are the three segmented integrated Dopplers before the measurement time, which are sequentially stored in S4. The three segments of integrated Doppler are of equal length and are , , , Respectively represent , , The Doppler frequency shift value at the center of each segment. Solve the Doppler frequency shift value at the measurement time The calculation process is as follows:

[0061] Based on the carrier phase difference method, it can be considered that the differential carrier phase between epochs can be divided sufficiently finely, that is, When it approaches 0, there is (for details, please refer to Figure 2 ):

[0062] (14)

[0063] (15)

[0064] (16)

[0065] Using a method similar to the first-order central difference of the carrier phase approximation, we can know that:

[0066] (17)

[0067] (18)

[0068] (19)

[0069] Substituting formula (18) and formula (19) into formula (17), we can obtain:

[0070] (20)

[0071] Substituting formula (14), formula (15) and formula (16) into formula (20), we can obtain:

[0072] (twenty one)

[0073] Therefore, the Doppler frequency shift at the measurement time can be obtained without using the two-segment integrated Doppler averaging method before and after the measurement of the observed quantity, eliminating the delay caused by the before and after averaging method, improving the real-time performance of speed measurement, and solving the problem of not being able to obtain the accurate receiver position and speed at the measurement time.

[0074] The present invention also provides a piecewise integral Doppler estimation satellite navigation speed measurement system, which mainly comprises a baseband processing module, a carrier smoothing pseudo-range module, a Doppler estimation module and a positioning solution module.

[0075] The baseband processing module realizes the acquisition and tracking of satellite signals and provides raw pseudorange and carrier phase measurement values;

[0076] The carrier smoothing pseudorange module realizes the carrier phase smoothing pseudorange function and performs carrier phase differentiation to obtain the segmented integrated Doppler value;

[0077] The Doppler estimation module calculates the Doppler frequency shift value at the measurement time based on the piecewise integrated Doppler value and provides the pseudorange rate;

[0078] The positioning solution module performs positioning solution processing based on carrier phase, smoothed pseudorange and pseudorange rate. When the number of satellites sent in is greater than or equal to 4, the position, speed and time of the receiver can be calculated.

[0079] Compared with the prior art, this application has the following differences:

[0080] 1) Based on the carrier smoothed pseudorange, the piecewise integral Doppler method is used to estimate the Doppler measurement value at the measurement time in advance.

[0081] 2) The Doppler measurement values ​​of each satellite are estimated in advance, and the method used in the advance estimation is unique in logic and practical.

[0082] Technical effects and advantages of the present invention:

[0083] 1) The present invention uses the Doppler estimation method to remove the delay caused by the forward and backward averaging method, improves the real-time performance of positioning and speed measurement, and makes it possible to obtain more accurate position and speed at the measurement time.

[0084] 2) The Doppler estimation method of the present invention can be quickly applied to the receiver on the original basis, supports accurate speed measurement when the carrier is rotating, and is more conducive to engineering implementation.

[0085] 3) The present invention designs a method for estimating Doppler frequency shift in advance, which improves the real-time performance of receiver positioning and testing, and is more suitable for the application of receiver carriers in medium and high dynamic environments.

[0086] 4) The present invention is based on the carrier phase differential speed measurement method, which uses the piecewise integral Doppler to estimate the Doppler frequency shift at the measurement time in real time, and provides a way to estimate the Doppler frequency shift at the measurement time, that is, to estimate and calculate the Doppler frequency shift in the observation dimension, instead of using position differential speed measurement in the positioning solution module to solve the problem of positioning and speed measurement delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is a schematic diagram of a flow chart for implementing the method of the present invention;

[0088] Figure 2 It is a schematic diagram of Doppler estimation;

[0089] Figure 3 It is a schematic diagram of the implementation of the system of the present invention;

[0090] Figure 42. It is a schematic diagram of time delay of the carrier phase differential averaging method in the embodiment;

[0091] Figure 5 1 is a schematic diagram of time delay of the piecewise integral Doppler estimation method in an embodiment. DETAILED DESCRIPTION

[0092] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0093] The following is in conjunction with the instruction manual Figure 1-5 The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0094] like Figure 1 As shown:

[0095] S1: poll all channels of baseband operation to determine whether the channel is valid. If not, traverse the next channel until all channels are traversed. If the channel is valid, set the carrier phase, pseudorange and pseudorange rate of the channel to invalid, and enter S2;

[0096] S2: Obtain all observations of the channel, including carrier phase observations and pseudorange observations;

[0097] S3: Calculate the original pseudorange and carrier phase respectively;

[0098] S4: Perform carrier phase difference between epochs to obtain segmented integrated Doppler, and store them sequentially with the channel as the index;

[0099] S5: Use the piecewise integral Doppler estimation algorithm to estimate the Doppler at the current measurement time in real time and convert it into a pseudorange rate. The conversion relationship between Doppler and pseudorange rate is shown in formula (5): ; Using the carrier phase, the carrier smoothing pseudorange method is adopted to calculate the smoothed pseudorange.

[0100] S6: The carrier phase, smoothed pseudorange, and pseudorange rate obtained through the above processing are sent to the positioning solution module. When the number of satellites sent is greater than or equal to 4, the position, speed, and time of the receiver can be calculated using the least square solution. The number of satellites and the number of channels are in a one-to-one correspondence, that is, one channel tracks one satellite.

[0101] In S2, the carrier phase related observations are the latched carrier integer count and carrier fractional phase, which together constitute the complete carrier phase. The pseudorange related observations are five items: message frame count, message bit count, message bit millisecond count, millisecond chip count, and code phase count;

[0102] In S3, the calculation of carrier phase is mainly to use the original pseudo-range to initialize the distance value that conforms to the physical meaning, and then use the carrier difference between epochs to calculate it. The original calculation is mainly to subtract the signal transmission time synthesized by the five count values ​​of the pseudo-range from the local time.

[0103] In S5, the segmented integrated Doppler values ​​sequentially stored in S4 are obtained to perform Doppler estimation at the current measurement moment. , , They are the three segmented integrated Dopplers before the measurement time, which are sequentially stored in S4. The three segments of integrated Doppler are of equal length and are , , , Respectively represent , , The Doppler frequency shift value at the center of each segment. Solve the Doppler frequency shift value at the measurement time The calculation process is as follows:

[0104] Based on the carrier phase difference method, it can be considered that the differential carrier phase between epochs can be divided sufficiently finely, that is, When it approaches 0, there is. For details, please refer to Figure 2 :

[0105] (14)

[0106] (15)

[0107] (16)

[0108] Using a method similar to the first-order central difference of the carrier phase approximation, we can know that:

[0109] (17)

[0110] (18)

[0111] (19)

[0112] Substituting formula (18) and formula (19) into formula (17), we can obtain:

[0113] (20)

[0114] Substituting formula (14), formula (15) and formula (16) into formula (20), we can obtain:

[0115] (twenty one)

[0116] Therefore, the Doppler frequency shift at the measurement time can be obtained without using the two-segment integrated Doppler averaging method before and after the measurement of the observed quantity, eliminating the delay caused by the before and after averaging method, improving the real-time performance of speed measurement, and solving the problem of not being able to obtain the accurate receiver position and speed at the measurement time.

[0117] The present invention tests the speed measurement performance of the segmented integral Doppler estimation method and the carrier phase differential averaging method for different dynamic scenarios of the carrier, and analyzes the delay of speed measurement. The test results are as follows:

[0118] Quasi-static (carrier speed 30m / s, acceleration 0.5g) speed measurement accuracy comparison:

[0119] Table 1

[0120]

[0121] The speed measurement accuracy of the integral Doppler estimation method and the carrier phase differential averaging method under quasi-static conditions is comparable, and both meet the general speed measurement index requirement of 0.2m / s.

[0122] Comparison of speed measurement accuracy in medium dynamics (carrier speed 3000m / s, acceleration 30g):

[0123] Table 2

[0124]

[0125] The speed measurement accuracy of the medium dynamic wave phase differential averaging method is slightly better than that of the segmented integral Doppler estimation method, but both methods fully meet the general speed measurement index requirement of 0.2m / s.

[0126] Time delay comparison

[0127] a. Carrier phase differential averaging method time delay such as Figure 4 As shown:

[0128] The blue line is the PPS pulse with a pulse width of 100ms. The green line is the positioning result output by the receiver. The positioning result output delay is about 60ms, of which the speed measurement delay is 50ms, and the positioning and speed measurement calculation takes about 10ms.

[0129] b. Segmented integral Doppler estimation method time delay Figure 5 As shown:

[0130] The blue line is the PPS pulse with a pulse width of 100ms. The green line is the positioning result output by the receiver. The positioning result output delay is about 10ms, all of which is time-consuming for positioning and speed measurement calculation.

[0131] In summary, the adaptability of the piecewise integral Doppler estimation method under different dynamic conditions has been verified. While ensuring good speed measurement accuracy, it eliminates the time delay caused by the differential carrier phase average speed measurement method, improves the real-time performance of positioning and speed measurement, and solves the problem of being unable to obtain the accurate receiver position and speed at the measurement time.

[0132] The present invention also provides a piecewise integral Doppler estimation satellite navigation speed measurement system, which mainly includes a baseband processing module, a carrier smoothing pseudorange module, a Doppler estimation module and a positioning solution module. Figure 3 :

[0133] The baseband processing module realizes the acquisition and tracking of satellite signals and provides raw pseudorange and carrier phase measurement values;

[0134] The carrier smoothing pseudorange module realizes the carrier phase smoothing pseudorange function and performs carrier phase differentiation to obtain the segmented integrated Doppler value;

[0135] The Doppler estimation module calculates the Doppler frequency shift value at the measurement time based on the piecewise integrated Doppler value and provides the pseudorange rate;

[0136] The positioning solution module performs positioning solution processing based on carrier phase, smoothed pseudorange and pseudorange rate. When the number of satellites sent in is greater than or equal to 4, the position, speed and time of the receiver can be calculated.

[0137] The above are preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the attached claims.

[0138] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided by the present invention and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0139] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

Claims

1. A satellite navigation segmented integral Doppler velocity measurement method under carrier rotation, characterized in that: The following steps are involved: S1: poll all channels of baseband operation to determine whether the channel is valid. If the channel is invalid, traverse the next channel until all channels are traversed. If the channel is valid, set the carrier phase, pseudorange and pseudorange rate of the valid channel to invalid, and enter S2; S2: Obtain all observations of the valid channel; S3: Calculate the original pseudorange and carrier phase respectively; S4: performing carrier phase difference between epochs to obtain segmented integrated Doppler, and sequentially storing them with the effective channel as index; S5: Use the piecewise integral Doppler estimation algorithm to estimate the Doppler at the current measurement time in real time and convert it into a pseudorange rate; use the carrier phase and the carrier smoothing pseudorange method to calculate the smoothed pseudorange; S6: The carrier phase, smoothed pseudorange and pseudorange rate obtained through the processing of S1-S5 are sent to the positioning solution module.

2. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: All observations of the effective channel are obtained, including carrier phase observations and pseudorange observations.

3. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: The conversion relationship between Doppler and pseudorange rate is shown in formula (1): （1）； Where n=1,2,…,N is the number of the satellite measurement value. is the pseudorange rate, is the raw Doppler measurement, is the wavelength.

4. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: When the number of satellites sent in is greater than or equal to 4, the least squares solution is used to calculate the position, speed, and time of the receiver. There is a one-to-one correspondence between the number of satellites and the number of channels, so one channel can track one satellite.

5. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: In S2, the relevant observation quantities of the carrier phase are the latched carrier integer count and carrier fractional phase, which together constitute the complete carrier phase. The relevant observation quantities of the pseudorange are five items, namely, message frame count, message bit count, millisecond count within message bit, code bit count within millisecond, and code phase count.

6. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: In S3, the calculation of the carrier phase is mainly obtained by initializing the original pseudorange to a distance value that conforms to the physical meaning, and then calculating it using the carrier difference between epochs. The original calculation is mainly obtained by subtracting the signal transmission time synthesized by the five count values ​​of the pseudorange from the local time.

7. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 1, characterized in that: In S5, the segmented integrated Doppler values ​​sequentially stored in S4 are obtained to perform Doppler estimation at the current measurement moment.

8. The satellite navigation segmented integral Doppler velocity measurement method under carrier rotation according to claim 7, characterized in that Solve the Doppler frequency shift value at the measurement time The calculation process is as follows: Based on the carrier phase difference method, the differential carrier phase between epochs is divided finely enough, that is, When it approaches 0, we have: （2） （3） （4） Using a method similar to the first-order central difference of the carrier phase approximation, we can know that: （5） （6） （7） Substituting formula (6) and formula (7) into formula (5), we can obtain: （8） Substituting formula (2), formula (3) and formula (4) into formula (8), we can get: （9） in, , , They are the three segmented integrated Dopplers before the measurement time, which are sequentially stored in S4. The three segments of integrated Doppler are of equal length and are , , , Respectively represent , , The Doppler shift value at the center of each segment.

9. A satellite navigation piecewise integrated Doppler velocity measurement system under carrier rotation, the system is based on the method according to any one of claims 1 to 8 to implement satellite navigation piecewise integrated Doppler velocity measurement under carrier rotation, characterized in that: It includes baseband processing module, carrier smoothing pseudorange module, Doppler estimation module and positioning solution module; The baseband processing module realizes the acquisition and tracking of satellite signals and provides raw pseudorange and carrier phase measurement values; The carrier smoothing pseudorange module realizes the carrier phase smoothing pseudorange function and performs carrier phase differentiation to obtain the segmented integrated Doppler value; The Doppler estimation module calculates the Doppler frequency shift value at the measurement time based on the piecewise integrated Doppler value and provides the pseudorange rate; The positioning solution module performs positioning solution processing based on carrier phase, smoothed pseudorange and pseudorange rate.

10. The satellite navigation segmented integral Doppler velocity measurement system under carrier rotation according to claim 9, characterized in that: When the number of satellites sent in is greater than or equal to 4, the position, speed and time of the receiver can be calculated.

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