Positioning method and device for high-speed rolling aircraft based on Doppler positioning

Abstract

The application relates to the technical field of rotary aircraft positioning, in particular to a positioning solution method and device for a high-speed rolling aircraft based on Doppler positioning, which removes the influence of high-order residual errors and noises by adding a rotary frequency detection module, an adaptive loop filter parameter optimization module and an adaptive coherent integration time adjustment module, improves the rotary Doppler frequency shift estimation accuracy by improving the aircraft attitude estimation accuracy, so as to strip the rotary Doppler frequency shift. Specifically, the current rotating speed information of the aircraft is detected, different loop parameters are set, the convergence time and loop attenuation are reduced, the coherent integration time is adjusted, and the influence of high-frequency components is eliminated, so that the problems of difficult attitude extraction caused by sudden change of rotating speed and large change amplitude of carrier-to-noise ratio during flight and low rotating speed estimation accuracy caused by high-frequency residual errors are solved, the rotary Doppler frequency shift estimation accuracy is improved, and the attitude estimation performance and positioning accuracy of the receiver under high rotating speed are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rotating aircraft positioning, in particular to a positioning solution method and device for high-speed rolling aircraft based on Doppler positioning. BACKGROUND

[0002] Satellite navigation positioning system has become one of the main positioning methods for rotating aircraft due to its all-weather and low cost advantages. Doppler positioning mainly uses frequency shift caused by relative velocity for calculation, and does not directly rely on pseudorange observation. The aircraft in flight has the characteristics of high speed and high maneuverability, which makes the traditional pseudorange positioning accuracy decline, while Doppler positioning has certain dynamic resistance.

[0003] L-3 Communications Holdings proposed a satellite-based rolling attitude detection method. This method uses the 1ms correlation accumulation value of the code tracking loop to extract the rotation speed and rolling angle. This technology has been successfully applied to the airborne receiver developed by the company. Mayflower communications company proposed a roll attitude measurement solution under antenna rotation conditions, which measures the position and roll attitude of the aircraft by demodulating the rotating amplitude modulation signal.

[0004] However, the above research does not conduct theoretical analysis and is not suitable for high rotation speed conditions. The signal attenuation caused by the high-speed rotation of the aircraft itself and external interference during flight leads to the decrease of carrier-to-noise ratio. At the same time, the rotation speed of most rotating aircraft is between 3r / s-300r / s, so the order, noise bandwidth and integration time of the phase-locked loop filter used to track the rotation frequency need to be specially designed. SUMMARY

[0005] The purpose of the present application is to provide a positioning solution method and device for high-speed rolling aircraft based on Doppler positioning, aiming to solve the problems of difficult attitude extraction caused by sudden change of rotation speed and large change range of carrier-to-noise ratio during flight, and decrease of rotation speed estimation accuracy caused by high-frequency residual, improve the estimation accuracy of rotating Doppler shift, and further improve the positioning accuracy based on Doppler positioning.

[0006] To achieve the above purpose, the present application provides a positioning solution method and device for high-speed rolling aircraft based on Doppler positioning, comprising the following steps:

[0007] Step 1: input the values of Doppler shift and code phase offset captured in advance into the carrier NCO and code NCO;

[0008] Step 2: intercept 1 ms of the intermediate frequency input signal, carrier NCO generates the in-phase carrier and the input intermediate frequency signal is multiplied to obtain the i branch, the quadrature phase carrier and the input intermediate frequency signal are multiplied to obtain the q branch; then the i and q branches are multiplied with the code NCO respectively;

[0009] Step 3: after the input intermediate frequency signal is sequentially subjected to carrier stripping and pseudo code stripping, the i and q branches are subjected to correlation accumulation to obtain I p , Q p two branches;

[0010] Step 4: the obtained two instant branches I p , Q p values are multiplied to serve as the input signal of the rotation tracking loop;

[0011] Step 5: the pre-estimated rotation frequency value is input into the rotation NCO, the i branch and the q branch are multiplied with the input signal obtained in step 4, and correlation accumulation is performed to generate I r , Q r branches;

[0012] Step 6: the I r , Q r branches in step 5 are sent into a discriminator to obtain the phase difference between the local copied rotation frequency and the real rotation frequency, which is input into the rotation NCO after passing through a loop filter to dynamically adjust the rotation frequency value;

[0013] Step 7: the output value of the rotation NCO adjusted in step 6 is input into the rotation frequency detection module for frequency detection, and when the frequency change exceeds a threshold value, the filter parameter and the coherent integration time are adaptively adjusted;

[0014] Step 8: the obtained rotation frequency is converted into a rotation speed, and after calculation, a rotation Doppler shift generated by rotation is obtained;

[0015] Step 9: the Doppler shift f s obtained by the carrier NCO is subtracted from the rotation Doppler shift f r obtained in step 8 to obtain a Doppler shift f d generated due to the relative motion of the satellite and the receiver;

[0016] Step 10: the position information and the speed information of m satellites are loaded through ephemeris;

[0017] Step 11: the Doppler shift f d obtained in step 9, the satellite position and speed information extracted in step 10, and the receiver information are used to construct m sets of Doppler shift observation equations;

[0018] Step 12: Iterative solution by least square method, load initial information of receiver for iterative operation, when the update value of last iteration is less than threshold, the updated solution value is taken as three-dimensional coordinate, velocity and clock drift value of receiver.

[0019] Optionally, the Doppler shift and code phase offset generated in the satellite signal process need to be captured in advance in step 1, to ensure alignment with the local pseudo code phase when tracking the signal subsequently.

[0020] The received rotating GNSS signal mathematical model is s(n):

[0021]

[0022] In the formula, P s is signal power; D i (n) is data code; C i (n) is C / A code; f IF is carrier intermediate frequency frequency; f d is Doppler shift caused by relative motion of satellite and receiver; f r is rotating Doppler shift caused by aircraft spinning; θ is initial carrier phase; n(n) is Gaussian white noise; f r The mathematical expression is

[0023]

[0024] In the formula, f L is carrier frequency of current frequency point satellite signal, Δd is offset between antenna phase center and rotation axis center, c is light speed, n is rotation speed, and α and β are angles between satellite signal and its projection on three-dimensional plane respectively.

[0025] Optionally, in step 2, the carrier NCO generates phase with Doppler offset, which is COS and SIN two-way carrier, and is multiplied with intermediate frequency input signal to obtain i branch containing all signal energy and q branch containing only noise.

[0026] Optionally, in step 3, the correlation accumulation obtains I p and Q p two branch calculation formulas are as follows:

[0027]

[0028] In the formula, N coh represents the number of correlation results input in coherent integration time.

[0029] Optionally, in step 4, I p and Q p two-way correlation values are multiplied to generate sinusoidal signal with rotating frequency as periodic frequency, and the formula is:

[0030]

[0031] wherein n' represents a Gaussian white noise with a mean of zero.

[0032] Optionally, in the process of step 7 adaptive loop filter parameter optimization, a second-order frequency-locked loop is used to assist a third-order phase-locked loop.

[0033] The coherent integration adjustment formula is:

[0034]

[0035] wherein f i , f i-1 respectively represent the current moment and the last moment of the rotation NCO output value, N is equal to a positive integer, and ΔT represents a coherent integration time adjustment amount.

[0036] Optionally, the rotation frequency obtained in step 8 is converted into a rotation speed, and then a rotation Doppler shift generated by rotation is obtained according to the rotation Doppler shift formula in step 1, and the calculation formula is as follows:

[0037]

[0038] Optionally, the m sets of Doppler shift observation equation expressions in step 11 are as follows:

[0039]

[0040] wherein x is a state variable, represents a receiver clock drift, represents the speed of the mth satellite, represents the position of the mth satellite, c represents the speed of light, represents the transmission frequency of the mth satellite, and ε f represents a process measurement error, and the receiver position p r =[x r, y r, z r, ], the equation contains 7 state variables, and the number m of satellites participating in positioning is greater than or equal to 7.

[0041] Further, the application further provides a positioning solution device for a high-speed rolling aircraft based on Doppler positioning, which adopts the positioning solution method for the high-speed rolling aircraft based on Doppler positioning, and comprises a signal receiving and processing module, a signal intercepting module, a carrier loop / code loop module, a rotation tracking loop module, a rotation frequency detecting module, an adaptive filter parameter optimization module, an adaptive coherent integration time adjustment module, a rotation Doppler stripping module, and a Doppler positioning solution module.

[0042] The signal receiving processing module is configured to acquire a discrete digital intermediate frequency rotating aircraft satellite receiving signal, multiply the digital intermediate frequency signal with a local cosine carrier to obtain a branch signal.

[0043] The signal intercepting module is configured to intercept the signal after stripping the carrier and track the subsequent signal.

[0044] The carrier loop / code loop module is configured to adjust the local copied carrier and code phase in real time so as to be consistent with the carrier frequency and code phase of the input signal.

[0045] The rotating tracking loop module includes a discriminator, a filter and a rotating NCO. The input I p ×Q p signal contains a real rotating frequency, estimate the rotating speed information of the current aircraft, obtain the phase difference between the local copied rotating frequency and the real rotating frequency, and after the loop filter, the phase difference is taken as the input of the rotating NCO to dynamically adjust the value of the local copied rotating frequency.

[0046] The rotating frequency detection module is configured to detect the rotating frequency value estimated by the current rotating NCO and judge whether the rotating frequency value exceeds a threshold value.

[0047] The adaptive filter parameter optimization module is configured to adaptively adjust the noise bandwidth and damping coefficient of the current loop filter according to the rotating speed obtained by the rotating frequency detection module.

[0048] The adaptive coherent integration time adjustment module is configured to adaptively adjust the current coherent integration time to be an integer multiple of the rotating frequency period according to the rotating speed obtained by the rotating frequency detection module.

[0049] The rotating Doppler stripping module is configured to calculate the Doppler shift f d caused by relative motion.

[0050] The Doppler positioning solution module is configured to construct a Doppler shift positioning equation set to obtain a final result.

[0051] The application provides a positioning solution method and device for a high-speed rolling aircraft based on Doppler positioning. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0053] Figure 1 is a principle block diagram of a positioning solution method for a high-speed rolling aircraft based on Doppler positioning.

[0054] Figure 2 is a flowchart of adaptive adjustment of filter parameters and coherent integration time in the positioning solution method for the high-speed rolling aircraft based on Doppler positioning. DETAILED DESCRIPTION

[0055] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0056] Some commonly used terms in the present application are replaced by English abbreviations, and the following is an explanation of the English terms in the present application:

[0057] NCO, Numerically Controlled Oscillator, numerical controlled oscillator.

[0058] The application provides a positioning solution method for a high-speed rolling aircraft based on Doppler positioning, comprising the following steps:

[0059] Step 1: input the Doppler shift and code phase shift values previously captured into the carrier NCO and code NCO;

[0060] Step 2: input the intermediate frequency signal of 1 ms, the carrier NCO generates the in-phase carrier and multiplies the input intermediate frequency signal to obtain the i branch, and the quadrature-phase carrier multiplies the input intermediate frequency signal to obtain the q branch; then the i and q branches are multiplied by the code NCO;

[0061] Step 3: after the input intermediate frequency signal is sequentially subjected to carrier stripping and pseudo-code stripping, the i and q branches are subjected to correlation accumulation to obtain I p , Q p two branches;

[0062] Step 4: multiply the obtained two instant branches I p , Q p values to obtain the input signal of the rotation tracking loop;

[0063] Step 5: input the previously estimated rotation frequency value into the rotation NCO to generate the in-phase branch and the quadrature branch, which are multiplied by the input signal obtained in step 4 and subjected to correlation accumulation to generate I r , Q r branches;

[0064] Step 6: input the I r , Q r branches in step 5 into the discriminator to obtain the phase difference between the local copied rotation frequency and the real rotation frequency, which is subjected to loop filtering and then input into the rotation NCO as the input of the rotation NCO to dynamically adjust the rotation frequency value;

[0065] Step 7: input the output value of the adjusted rotation NCO in step 6 into the rotation frequency detection module to perform frequency detection, and when the frequency change exceeds a threshold value, the filter parameter and the coherent integration time are adaptively adjusted;

[0066] Step 8: the obtained rotation frequency is converted into the rotation speed, and the rotation Doppler shift generated by the rotation is calculated;

[0067] Step 9: subtract the rotation Doppler shift f r obtained in step 8 from the Doppler shift f s obtained by the carrier NCO to obtain the Doppler shift f d generated due to the relative motion between the satellite and the receiver;

[0068] Step 10: load the position information and speed information of m satellites through ephemeris;

[0069] Step 11: subtract the Doppler shift f d, the satellite position and velocity information extracted in step 10, and the receiver information, to construct m sets of Doppler frequency shift observation equations;

[0070] Step 12: iterative solution is performed by using the least square method, initial information of the receiver is loaded for iterative operation, and when the update value of the last iteration is less than a threshold value, the updated solution value is taken as the three-dimensional coordinates, velocity and clock drift value of the receiver.

[0071] The specific technical solution structure block diagram is shown in Figure 1 The following will be further described in combination with specific execution steps:

[0072] In step 1, the parameters that must be obtained before tracking are the Doppler frequency shift and code phase offset generated in the satellite signal process, which are input to the carrier NCO and code NCO. This step can ensure that the subsequent tracking signal can be basically aligned with the local pseudo code phase, reducing the loss of signal-to-noise ratio.

[0073] The received rotating GNSS signal mathematical model is s(n):

[0074]

[0075] In the formula, P s is the signal power; D i (n) is the data code; C i (n) is the C / A code; f IF is the carrier intermediate frequency frequency; f d is the Doppler frequency shift caused by the relative motion of the satellite and the receiver; f r is the rotating Doppler frequency shift caused by the aircraft spinning; θ is the initial carrier phase; n(n) is the Gaussian white noise; f r The mathematical expression is

[0076]

[0077] In the formula, f L is the carrier frequency of the current frequency point satellite signal, Δd is the offset between the antenna phase center and the rotation axis center, c is the speed of light, n is the rotation speed, and α and β are the angles between the satellite signal and its projections on the three-dimensional plane, respectively.

[0078] Step 2: the carrier NCO generates two carrier waves with Doppler offset phase COS and SIN, which are multiplied by the intermediate frequency input signal to obtain the i branch containing all signal energy and the q branch containing only noise. The adjustment of the carrier tracking loop and the code tracking loop makes the signal power output by the i branch maximum in the whole tracking process, and makes the q branch output contain only noise as much as possible, thereby reducing the loss of signal strength. The signal is as follows:

[0079]

[0080] Where D(n) represents the navigation data level, R(δ) represents the C / A code autocorrelation function, and θ(t) represents the phase difference caused by the relative motion between the satellite and the receiver.

[0081] Step 3: The correlation results of Step 2 are sent into integrators respectively, and the addition and accumulation operations are performed to obtain I p and Q p branches. The following shows:

[0082]

[0083]

[0084] Where N coh represents the number of correlation results inputted within the coherent integration time.

[0085] Step 4: I p × Q p contains the rotation speed information, and a sine signal with a periodic frequency of the rotation frequency is generated by multiplying the I p and Q p correlation values, and the formula is represented as:

[0086]

[0087] Where n' represents the Gaussian white noise with a mean of zero.

[0088] Step 5: The data obtained in Step 4 is taken as the input of the rotation tracking loop, and the frequency pre-loaded into the rotation NCO is multiplied and correlated to accumulate, to generate I r and Q r branches:

[0089]

[0090] Where K is the amplitude, θ i and w i are the initial phase and angular frequency of the input signal respectively, θ o and w o are the initial phase and angular frequency of the local copy respectively, w e and θ e are the frequency difference and phase difference respectively.

[0091] Step 6: I r and Q rThe carrier phase discrimination method can also adopt various methods, but the two-quadrant arctangent function phase discriminator is the most accurate among various Costa phase-locked loop discriminators. Then, the phase difference passes through the carrier loop filter and adjusts the rotation frequency tracking value through the rotation NCO.

[0092]

[0093] In step 7, the updated frequency value is input into the frequency detection module for frequency detection, and when the frequency exceeds the threshold value, the filter parameters and the coherent integration time are adaptively adjusted, and the flowchart is as shown in Figure 2

[0094] Adaptive loop filter parameter optimization: since the aircraft is in a high dynamic environment during flight, the aircraft carrier appears rapid jitter, and the rotation speed of most aircraft is between 3r / s-300r / s, so the order, noise bandwidth and damping coefficient of the phase-locked loop filter for tracking the rotation modulation signal need to be specially designed. Therefore, the application adopts a second-order frequency-locked loop to assist a third-order phase-locked loop, which has higher dynamic stress and can more accurately and quickly track the phase of the input signal. At the same time, by detecting the real rotation speed of the current aircraft, the current noise bandwidth and damping coefficient of the filter are adaptively adjusted, so that the loop convergence time is smaller, the tracking accuracy is higher, and the attenuation is less than 3dB.

[0095] Adaptive coherent integration time adjustment: for the rotation modulation signal, it belongs to low frequency and weak signal, and is easily disturbed by high frequency components and noise, which affects the discriminator. Therefore, it is necessary to adjust the coherent integration time to solve the problem of tracking accuracy decline caused by high-order harmonics. According to the expression of I r , Q r signals obtained in S5, it can be obtained that when the integration time T coh is equal to an integer multiple of the period of the input signal, the high frequency components in I r (n) and Q r (n) can be eliminated by integration. The formula derivation is as follows:

[0096]

[0097] where (w i +w o )=4πf r , (n=1,2,3…), n is a positive integer. Therefore, in order to filter out high frequency components, the coherent integration time is adjusted in real time by detecting the current rotation frequency. The coherent integration adjustment formula is as follows:

[0098]

[0099] f​i f i-1 These represent the output values ​​of the rotating NCO at the current and previous times, respectively, where N is a positive integer and ΔT represents the coherent integration time adjustment.

[0100] In step 8, the rotational frequency obtained in step 6 is converted into rotational speed, and then the rotational Doppler frequency shift generated by the rotation is obtained according to the rotational Doppler frequency shift formula in step 1:

[0101]

[0102] Step 9: Since the aircraft is rotating, there is a rotational Doppler frequency shift caused by the rotation. Therefore, the Doppler frequency shift received by the receiver includes the Doppler frequency shift caused by relative motion and the Doppler frequency shift caused by rotation. To construct the Doppler localization equation, the rotational Doppler frequency shift needs to be removed. The total Doppler frequency shift f obtained by subtracting the carrier NCO is... s Subtract the rotational Doppler frequency shift f obtained in S8 r The Doppler frequency shift f caused by the relative motion between the satellite and the receiver is obtained. d .

[0103] Step 10: The satellite ephemeris contains the positions P of m satellites loaded via ephemeris. s [x,y,z] and velocity information V s [v x ,v y ,v z ].

[0104] Step 11: Based on the Doppler frequency shift of m satellites obtained from S9 Positions P of m satellites extracted from ephemeris s [x,y,z] and velocity information V s [v x ,v y ,v z and receiver position P r =[x r ,y r ,z r ]、 Construct m sets of Doppler frequency shift observation equations.

[0105]

[0106] in, For state variables, Indicates receiver clock drift. This represents the velocity of the m-th satellite. Let m represent the position of the m-th satellite, and c represent the speed of light. Let ε represent the transmission frequency of the m-th satellite. fThe process measurement error is represented. The above equation contains 7 state variables, and the number of satellites participating in positioning m≥7.

[0107] S12: using the least square method to iteratively solve, when the update value of the last iteration is less than the threshold value, the updated solution value is taken as the final value of the three-dimensional coordinates, speed and clock drift value of the receiver. Doppler positioning matrix:

[0108]

[0109] G is the Jacobian function, after k iterations, when the correction value ΔS r is less than the threshold value, the k+1 result is the final solution result:

[0110]

[0111] Further, the application also proposes a positioning solution device for high-speed rolling aircraft based on Doppler positioning, which adopts the positioning solution method for high-speed rolling aircraft based on Doppler positioning, and includes a signal receiving and processing module, a signal intercepting module, a carrier loop / code loop module, a rotating tracking loop module, a rotating frequency detecting module, an adaptive filter parameter optimization module, an adaptive coherent integration time adjusting module, a rotating Doppler stripping module, and a Doppler positioning solution module.

[0112] Specifically, the signal receiving and processing module is used to acquire discrete digital intermediate frequency satellite receiving signals of the rolling aircraft, and to multiply the digital intermediate frequency signals with local cosine carriers to obtain in-phase i p signals; similarly, multiplying with local sine carriers can obtain q p signals. The signal model is represented as follows:

[0113]

[0114] The signal intercepting module is used to intercept the signals after stripping the carriers, and to take a period length of signals (1ms) after frame synchronization each time for subsequent signal tracking.

[0115] The carrier loop / code loop module is used to adjust the local copied carrier and code phase in real time to make them consistent with the carrier frequency and code phase of the input signals.

[0116] The rotating tracking loop module includes a discriminator, a filter and a rotating NCO. The real rotating frequency contained in the input I p ×Q p signals is detected in real time to estimate the rotating speed information of the current aircraft, and the local copied rotating frequency is dynamically adjusted to make it consistent with the real rotating speed.

[0117] Rotating frequency detection module: detect the rotating frequency value estimated by the current rotating NCO, and judge whether it exceeds the threshold value.

[0118] Adaptive filter parameter optimization module: through the rotating speed obtained by the rotating frequency detection module, the noise bandwidth and damping coefficient of the current loop filter are adaptively adjusted, and the loop reaches the optimal state. Reduce the loop convergence time, improve the loop tracking accuracy, and reduce the signal attenuation caused by tracking error.

[0119] Adaptive coherent integration time adjustment module: through the rotating speed obtained by the rotating frequency detection module, the current coherent integration time is adaptively adjusted to be an integer multiple of the rotating frequency period, the high frequency component is eliminated, the influence on the phase discriminator is reduced, and the loop tracking accuracy is improved.

[0120] Rotating Doppler stripping module: according to the current estimated rotating frequency, the rotating Doppler shift f caused by the current rotating speed is obtained through the formula r , then load the Doppler shift f in the carrier NCO s , and subtract the rotating Doppler to obtain the Doppler shift f caused by relative motion d . The formula is as follows:

[0121]

[0122] f d = f s -f r

[0123] Doppler positioning solution module: load the ephemeris of m satellites, obtain position and velocity information and construct Doppler shift positioning equation set, and solve by least square method to finally obtain receiver position, velocity and clock drift.

[0124] In summary, the present application has the following beneficial effects:

[0125] By real-time detection of the output frequency of the rotating NCO, when the detected frequency change exceeds the threshold value, the filter parameters and the coherent integration time are adaptively adjusted in real time, and the tracking performance of the rotating tracking loop is optimized. For low frequency signals, it is easy to be affected by high frequency components. By adjusting the coherent integration time to be an integer multiple of the frequency period, the influence of high order residual can be eliminated, and the accuracy and stability of rotating frequency tracking can be improved. Thus, the rotating Doppler shift is accurately stripped, and accurate parameter values are provided for the Doppler positioning equation set.

[0126] The above only discloses one or more preferred embodiments of the present application, and of course cannot limit the scope of the rights of the present application, and those skilled in the art can understand that all or part of the above-mentioned embodiments can be implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A method of position solution for a high-speed roll vehicle based on Doppler positioning, characterized by, The method comprises the following steps: Step 1: input the Doppler shift and code phase offset values pre-acquired into the carrier NCO and code NCO; Step 2: input the 1ms intercepted intermediate frequency signal, the carrier NCO generates the in-phase carrier and the input intermediate frequency signal is multiplied to obtain the i branch, and the quadrature-phase carrier and the input intermediate frequency signal are multiplied to obtain the q branch; then the i and q branches are multiplied with the code NCO respectively; Step 3: After the carrier and pseudo-code stripping of the input intermediate frequency signal, the i, q branches are correlated and accumulated to obtain I p , Q p two branches; Step 4: The resulting two instant branches I p , Q p are multiplied by the values of the phase and amplitude of the input signal of the rotation tracking loop; Step 5: The pre-estimated rotation frequency value is input into the rotation NCO, and the i-branch and q-branch are multiplied with the input signal obtained in step 4, respectively, and the correlation is accumulated to generate I r , Q r branches. Step 6: I r , Q r The branch is sent into the discriminator to get the phase difference between the local copy of the rotation frequency and the real rotation frequency, and after the loop filter, it is used as the input of the rotation NCO to dynamically adjust the rotation frequency value. Step 7: input the adjusted rotation NCO output value in step 6 into the rotation frequency detection module for frequency detection, and when the frequency change exceeds the threshold value, the filter parameter and the coherent integration time are adaptively adjusted; Step 8: the obtained rotation frequency is converted into the rotation speed, and the rotation Doppler shift generated by rotation is calculated according to the rotation Doppler shift formula in step 1; Step 9: The Doppler shift f s obtained from the carrier NCO is subtracted from the rotation Doppler shift f r obtained in step 8, resulting in the Doppler shift f d produced by the relative motion of the satellite and the receiver. Step 10: load the position information and speed information of m satellites through ephemeris; Step 11: Constructing m sets of Doppler frequency shift observation equations with Doppler frequency shift f d , satellite position and velocity information extracted in Step 10, and receiver information. Step 12: iterative calculation is performed by using the least square method, and the initial information of the receiver is loaded for iterative operation, and when the updated value of the last iteration is less than the threshold value, the updated calculation value is taken as the three-dimensional coordinates, speed and clock drift value of the receiver.

2. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 1, wherein, In step 1, the Doppler shift and code phase offset generated in the satellite signal process need to be pre-acquired to ensure that the local pseudo-code phase is aligned in the subsequent tracking signal; The received rotation GNSS signal mathematical model is s(n): where P s is the signal power; D i (n) is the data code; C i (n) is the C / A code; f IF is the carrier intermediate frequency; f d is the Doppler shift due to the relative motion of the satellite and receiver; f r is the rotational Doppler shift due to the vehicle spin; θ is the initial carrier phase; n(n) is the Gaussian white noise; f r The mathematical expression is wherein f L is the carrier frequency of the satellite signal at the current frequency, Δd is the offset between the phase center of the antenna and the center of the rotation axis, c is the speed of light, n is the rotation speed, and α and β are the angles between the satellite signal and its projection on the three-dimensional plane, respectively.

3. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 2, wherein, In step 2, the carrier NCO generates two carriers with Doppler offset phase COS and SIN, which are multiplied with the intermediate frequency input signal to obtain the i branch containing all signal energy and the q branch containing only noise.

4. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 3, wherein, The relevant accumulation in Step 3 obtains I p , Q p The calculation formulas of the two branches are as follows: where N coh represents the number of correlation results inputted within the coherent integration time.

5. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 4, wherein, In step 4, by I p , Q p The two correlation values are multiplied to generate a sinusoidal signal with a cycle frequency of the rotation frequency, which is expressed by the formula: Wherein, n' represents the Gaussian white noise with mean value of zero.

6. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 5, wherein, In the process of adaptive loop filter parameter optimization in step 7, a second-order frequency-locked loop is used to assist a third-order phase-locked loop; The coherent integration adjustment formula is: where f i , f i-1 represent the current time and the previous time rotation NCO output values, respectively, N is equal to a positive integer, and ΔT represents a coherent integration time adjustment amount.

7. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 6, wherein, In step 8, the obtained rotation frequency is converted into the rotation speed, and the rotation Doppler shift generated by rotation is obtained according to the rotation Doppler shift formula in step 1, and the calculation formula is as follows:

8. The positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to claim 7, wherein, The expression of the m-group Doppler shift observation equation in step 11 is as follows: where, is a state variable, denotes the receiver clock drift, denotes the velocity of the mth satellite, P s m denotes the position of the mth satellite, c denotes the speed of light, f s m denotes the transmission frequency of the mth satellite, ε f denotes the process measurement error, receiver position p r = [x r , y r , z r ,], The equation contains 7 state variables, and the number of satellites involved in positioning m >

7.

9. A positioning calculation device of a high-speed rolling aircraft based on Doppler positioning, which adopts the positioning calculation method of the high-speed rolling aircraft based on Doppler positioning according to any one of claims 1 to 8. The signal receiving processing module, the signal intercepting module, the carrier loop / code loop module, the rotation tracking loop module, the rotation frequency detecting module, the adaptive filter parameter optimizing module, the adaptive coherent integration time adjusting module, the rotation Doppler stripping module, and the Doppler positioning solving module are included. The signal receiving processing module is configured to acquire discrete digital intermediate frequency satellite receiving signals of a rotating aircraft, and multiply the digital intermediate frequency signals with a local cosine carrier to obtain branch signals. The signal intercepting module is configured to intercept the signals after the carrier stripping and subsequent signal tracking. The carrier loop / code loop module is configured to adjust the locally copied carrier and code phase in real time so as to be consistent with the carrier frequency and code phase of the input signals. The rotation tracking loop module comprises a discriminator, a filter, a rotation NCO; real-time detection of the I p xQ p The real rotation frequency contained in the signal, the rotation speed information of the current aircraft is estimated, the phase difference between the locally copied rotation frequency and the real rotation frequency is obtained, and after passing through the loop filter, it is input to the rotation NCO, dynamically adjusting the value of the locally copied rotation frequency. The rotation frequency detecting module is configured to detect the rotation frequency value estimated by the current rotation NCO, and determine whether the rotation frequency value exceeds a threshold value. The adaptive filter parameter optimizing module is configured to adaptively adjust the noise bandwidth and damping coefficient of the current loop filter according to the rotation speed obtained by the rotation frequency detecting module. The adaptive coherent integration time adjusting module is configured to adaptively adjust the current coherent integration time to be an integer multiple of the rotation frequency period according to the rotation speed obtained by the rotation frequency detecting module. The rotational Doppler stripping module is used to calculate the Doppler shift f caused by the relative motion d ; The Doppler positioning solving module is configured to construct a Doppler frequency shift positioning equation group to obtain a final result.

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