A low-computing GNSS dual-antenna orientation method

Abstract

A low-computing-power GNSS dual-antenna orientation method includes: step 1) initializing and preprocessing the dual-antenna observation values, that is, performing gross error elimination and cycle slip detection on the dual-antenna observation values ​​to ensure the quality of the GNSS observation values, step 2) performing RTK positioning of the dual-antenna position at the integer second to obtain the initial state, and repeating this step at each integer second to reset the position of the dual antenna, including: step 2‑1) RTK positioning of the master antenna position at the integer second, step 2‑2) RTK positioning of the slave antenna position at the integer second. If it is at a non-integer second, proceed to step 3); dual-antenna TDCP (time (epoch) differential carrier phase) positioning at a non-integer second: step 4) master and slave antenna orientation solution and step 5) master and slave antenna orientation result output. According to the present invention, low computing power, low cost, less time consumption, high orientation accuracy, low noise, low hardware requirements and no need for ambiguity fixation.

Description

Technical Field

[0001] The present invention belongs to the field of global satellite navigation and positioning technology. Specifically, the present invention relates to a low-computing-power GNSS (Global Satellite Navigation and Positioning System) dual-antenna orientation method. Background Art

[0002] In the GNSS global satellite navigation and positioning system, dual-antenna positioning and orientation solution can obtain high-precision position and attitude information. Through dual-antenna technology, the position, speed, attitude and other information of the carrier can be solved in real time to provide high-precision navigation and positioning services.

[0003] Dual-antenna positioning and orientation technology uses two antennas to receive satellite signals and calculates the position and attitude of the carrier by processing these signals. Specific methods include:

[0004] GNSS positioning: Satellite signals are received through two GNSS receiver antennas, and the baseline vector between the antennas is determined using high-precision carrier phase observations and fixed baseline length information to obtain the carrier's location information.

[0005] Directionality: By adjusting the phase difference between the two antennas, the carrier phase measurement and high-precision calculation are used to calculate the carrier's attitude information, such as pitch angle and azimuth angle.

[0006] In low-cost combined navigation and orientation methods, attitude information is often estimated by an inertial measurement unit (IMU) (a device that measures the three-axis attitude angle and acceleration of an object), but the heading estimation accuracy of the low-cost MEMS IMU (micro inertial measurement unit) is inaccurate, and it cannot estimate the heading in a static state. Dual-antenna GNSS can achieve static orientation with high orientation accuracy.

[0007] Dual-antenna GNSS is based on differential GPS technology, using two antennas placed at a certain distance (usually 30 cm to 2 meters), which is called a baseline. By measuring the time difference between the two antennas receiving satellite signals, the three-dimensional direction and position of the receiver can be calculated. Since the satellite is very far away from the earth, the electromagnetic waves it sends can be regarded as plane waves, which enables dual-antenna GNSS to provide high-precision positioning and orientation information, thereby determining the three-dimensional direction and position of the receiver for high-precision positioning and orientation applications.

[0008] The existing technology generally selects one antenna as the "rover" and the other antenna as the "base station", and uses the RTK algorithm (Real-time kinematic), which is a real-time dynamic carrier phase difference technology that processes the carrier phase observations of the two measurement stations for GPS measurement. RTK can send the carrier phase information collected by the base station to the user receiver in real time, and achieve centimeter-level positioning accuracy by solving the coordinate difference.

[0009] RTK can solve the baseline vector of the dual antennas, and then complete the calculation of the heading angle, pitch angle (or roll angle). This solution actually needs to complete two RTK solutions, namely the first RTK solution between the "base station" and the real base station, and the second RTK solution between the "base station" and the "rover". RTK has ambiguity problems and needs to estimate ambiguity parameters. Its computing power and time consumption will be relatively large, and it is difficult to support high-frequency orientation result output.

[0010] The authorized patent with application number "202310822029.7" discloses an inertial-assisted GNSS dual-antenna orientation method and device. The device integrates a GNSS dual-antenna measurement unit, an inertial measurement unit and a data processing module. It is a GNSS dual-antenna orientation method based on azimuth constraints, which can improve the speed, accuracy and orientation stability of baseline solution convergence.

[0011] The invention application "A GNSS dual-antenna directional state constraint method and system" with application number "202310857899.8" discloses a GNSS dual-antenna directional state constraint system. The invention is an independent baseline length constraint algorithm based on the posterior information estimated by Kalman filter, which can improve the dual-antenna directional accuracy in multipath environments and improve the heading stability of mobile carriers in complex environments with severe occlusion.

[0012] However, traditional solutions must have ambiguity fixed, and because the ambiguity fixing module is a relatively time-consuming and computationally intensive part of the algorithm, it results in greater computing power and time consumption, and also places higher requirements on the hardware platform. Summary of the invention

[0013] To overcome the problems existing in the past, the object of the present invention is:

[0014] In order to meet the high-frequency orientation result output and solve the problems of high computing power and high time consumption of traditional dual-antenna GNSS orientation, the present invention proposes a low-computing-power GNSS (Global Satellite Navigation and Positioning System) dual-antenna orientation method.

[0015] According to the invention, a low-computing-power GNSS (Global Navigation Satellite Positioning System) dual-antenna orientation method is a GNSS dual-antenna orientation algorithm with full-second dual RTK solution and non-full-second TDCP solution. The method solves the dual-antenna baseline vector based on the carrier phase difference (TDCP) between epochs, and then solves the attitude angle. Because the position at the non-full-second moment of the present invention is obtained by recursion of the carrier observation quantity, there is no ambiguity fixed at the non-full-second moment, and the accuracy of the carrier observation quantity is at the millimeter level, and the accuracy is very high. Therefore, the low-computing-power GNSS (Global Navigation Satellite Positioning System) dual-antenna orientation method according to the present invention has a lower computing power than the traditional scheme because there is only a step of fixing the ambiguity when solving the full-second moment, and there is no ambiguity fixed at the non-full-second moment, low computing power, less time consumption, higher dynamic orientation accuracy, and lower requirements on the hardware platform.

[0016] The technical solution of the present invention is as follows:

[0017] A low-computing-power GNSS dual-antenna orientation method, characterized in that the method comprises:

[0018] Step 1) Initialize and preprocess the dual-antenna observations, that is, remove gross errors and detect cycle slips to ensure the quality of GNSS observations.

[0019] Step 2) Perform RTK positioning of the dual antenna positions at the full second to obtain the initial state. Repeat this step every full second to reset the positions of the dual antennas, including:

[0020] Step 2-1) RTK positioning of the main antenna position at the second,

[0021] (2-1-a) Construct the single-difference carrier phase observation equation between the main antenna and the reference station.

[0022] (2-1-b) Calculate the double-difference carrier phase observation equation,

[0023] Step 2-2) RTK positioning from the antenna position at the whole second,

[0024] If it is not an integer second, go to step 3):

[0025] Step 3) Dual-antenna TDCP (time (epoch) differential carrier phase) positioning at non-integer seconds:

[0026] Step 3-1) Perform TDCP positioning of the main antenna position at a non-integer second.

[0027] (3-1-a) During the non-integer second period, TDCP is used to deliver the position to calculate the attitude angle.

[0028] Step 3-2) TDCP positioning from the antenna position at a non-integer second,

[0029] Step 4) Directional calculation of the master and slave antennas,

[0030] Step 5) Output the directional results of the master and slave antennas.

[0031] The RTK positioning of the antenna position starts from the whole second, and then the non-whole second positioning will be interspersed in time sequence. For example, if the output is required to be 20HZ, then after the whole second, there will be 0s (RTK) 0.05s (TDCP)

[0032] 0.1s(TDCP) 0.15s(TDCP) 0.2s(TDCP) .....1s(RTK) positioning, the difference between full second and part-full second is only in the positioning part.

[0033] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that in step 2),

[0034] (2-1-a) Construct the single-difference carrier phase observation equation of the main antenna and the reference station:

[0035] The carrier phase measurement value of satellite i by main antenna u and reference station r and Can be expressed as

[0036]

[0037]

[0038] Among them, λ and f are the wavelength and frequency of the satellite signal (m and Hz respectively);

[0039] are the distances from satellite i to the main antenna and reference station, respectively (m);

[0040] I and T are the ionosphere and troposphere delays;

[0041] δt u ,δt r They are the main antenna receiver delay and the base station receiver delay respectively;

[0042] are the integer ambiguities from satellite i to the main antenna and the reference station respectively;

[0043] are the observation noise of the carrier phase observation of the main antenna and the reference station,

[0044] The difference between equation (1) and equation (2) gives the single-difference observation equation between stations and the single-difference carrier phase observation equation of satellite j for the main antenna and the reference station:

[0045]

[0046] According to the present invention, for the short baseline system, the single difference ionospheric and tropospheric delays are approximately equal to 0, and equation (3) can be further simplified to:

[0047]

[0048] in:

[0049]

[0050] Similarly, the single-difference carrier phase observation equation of satellite j to the main antenna and reference station can be obtained:

[0051]

[0052] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that in step 2),

[0053] (2-1-b) Calculate the double-difference carrier phase observation equation:

[0054] The double difference observation equation can be obtained by subtracting equation (5) from equation (6)

[0055]

[0056] in:

[0057]

[0058] Further finishing includes:

[0059]

[0060] where b ur is the baseline vector, is the line of sight vector from satellite i to the receiver.

[0061] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0062] In step 2-2) the RTK positioning from the antenna position at the full second,

[0063] The baseline vector can be solved by equation (11). The main antenna position coordinates can be calculated when the base station position coordinates are known. Now the main antenna position has been obtained. The main antenna can be used as the "base station" and the slave antenna as the "mobile station". The slave antenna position coordinates can be calculated according to the above processes (2-1-a) and (2-1-b).

[0064] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that in step 3):

[0065] (Step 3-1) Perform TDCP positioning of the main antenna position at a non-integer second,

[0066] During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated.

[0067] Referring to formula (1), the carrier observation equation of satellite i to the main antenna at time t is listed as follows:

[0068]

[0069] Similarly, the carrier observation equation of satellite i to the main antenna at time t+1 is listed as follows:

[0070]

[0071] The difference between the two equations gives the TDCP observation equation:

[0072]

[0073] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0074] In step 3) in the dual-antenna TDCP positioning at non-integer seconds, the satellite clock error can be given by the ephemeris and deducted.

[0075] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0076] In step 3), dual-antenna TDCP (time (epoch) differential carrier phase) positioning at non-integer seconds:

[0077] Step (3-1-b) performs TDCP positioning of the slave antenna position at a non-integer second. The TDCP positioning method of the slave antenna is the same as that of the main antenna.

[0078] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0079] and are the unit vectors pointing from the satellite to the receiver at epoch t and t+1 respectively. Considering that the speed of the satellite is much greater than the speed of the vehicle, and Can be approximately equal, so according to the geometric relationship:

[0080]

[0081] In the above formula,

[0082] and are the satellite positions at epoch t+1 and t, respectively.

[0083] and are the corresponding receiver positions,

[0084] △r S and △r R are the geometric position increments of the satellite and the receiver in the Earth-centered Earth-fixed coordinate system (ECEF) between two epochs. Substituting them into equation (15), we can obtain:

[0085]

[0086] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0087] Constructing multiple formulas (15) TDCP observation equations can solve △r R , and then the main antenna position and the slave antenna position at the current moment are obtained.

[0088] According to the low computing power GNSS dual-antenna orientation method of the present invention, it is characterized in that:

[0089] Step 4) Directional calculation of the master and slave antennas,

[0090] If it is not an integer second, use the position of the previous moment and the carrier observation value of the current moment to recursively calculate the TDCP position of the master antenna and the slave antenna, and obtain the master and slave antenna positions at the current moment. The recursive formula is:

[0091]

[0092] Using the main antenna, the main antenna is pointed from the antenna coordinates. The projection of the slave antenna vector in the NED coordinate system is recorded as

[0093]

[0094] Then there are heading angle and pitch angle (or roll angle):

[0095]

[0096] In step 4), the dual antennas and the carrier are placed such that if the direction of the dual antenna connection is parallel to the vehicle's forward direction, the calculated attitude is the heading angle and the pitch angle; if the direction of the dual antenna connection is perpendicular to the vehicle's forward direction, the calculated attitude is the heading angle and the roll angle.

[0097] Excellent effects of the present invention

[0098] The present invention proposes a GNSS dual-antenna orientation algorithm with full-second dual RTK solution and non-full-second TDCP solution, which achieves low computing power, low time consumption, high-frequency output, dynamic orientation, and high orientation accuracy (equivalent to the traditional dual-antenna orientation accuracy), which is 0.15° / R, where R is the baseline distance (meters). That is, the orientation accuracy of a 1-meter baseline is 0.15°; the orientation accuracy of a 2-meter baseline is 0.15 / 2=0.075°.

[0099] In addition, according to the present invention, the noise is small, the hardware requirement is low and no ambiguity fixing is required.

[0100] The GNSS dual-antenna orientation method of the present invention has great use value in the current intelligent vehicle driving field. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 Schematic diagram of the relationship between the satellite and the receiver of the present invention.

[0102] Figure 2 The figure is a flow chart of the dual-antenna orientation method of GNSS of the present invention. DETAILED DESCRIPTION

[0103] Example

[0104] The GNSS dual-antenna orientation method of the present invention is used in the field of intelligent vehicle driving.

[0105] When initializing this method, you need to perform RTK positioning of the two antennas to obtain the initial state. Then repeat this step every full second to reset the positions of the two antennas.

[0106] Step 1: Remove gross errors and detect cycle slips from the master and slave antenna observations to ensure the quality of GNSS observations.

[0107] Step 2) Perform RTK positioning of the dual antenna positions at the full second to obtain the initial state. Repeat this step every full second to reset the positions of the dual antennas, including:

[0108] Step 2-1) RTK positioning of the main antenna position at the second,

[0109] (2-1-a) Construct the single-difference carrier phase observation equation between the main antenna and the reference station.

[0110] (2-1-b) Calculate the double-difference carrier phase observation equation,

[0111] Step 2-2) RTK positioning from the antenna position at the whole second,

[0112] If it is not an integer second, go to step 3):

[0113] Step 3) Dual-antenna TDCP (time (epoch) differential carrier phase) positioning at non-integer seconds:

[0114] Step 3-1) Perform TDCP positioning of the main antenna position at a non-integer second.

[0115] (3-1-a) During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated.

[0116] Step 3-2) TDCP positioning from the antenna position at a non-integer second,

[0117] Step 4) Directional calculation of the master and slave antennas,

[0118] Step 5) Output the directional results of the master and slave antennas.

[0119] In step 3: If it is an integer second, construct the double-difference carrier observation equation for the main antenna and the reference station

[0120]

[0121] Calculate the position of the main antenna; similarly construct the main antenna, and solve the position of the slave antenna using the double-difference carrier observation equation of the slave antenna.

[0122] In (step 3-1), the main antenna position TDCP positioning is performed at a non-integer second time.

[0123] During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated.

[0124] Referring to formula (1), the carrier observation equation of satellite i to the main antenna at time t is listed as follows:

[0125]

[0126] Similarly, the carrier observation equation of satellite i to the main antenna at time t+1 is listed as follows:

[0127]

[0128] The difference between the two equations gives the TDCP observation equation:

[0129]

[0130] In step 3) (3-1-b) the TDCP positioning of the slave antenna position at a non-integer second time, the TDCP positioning method of the slave antenna is the same as that of the main antenna.

[0131] In step 4): the master and slave antenna orientations are solved.

[0132] If it is not an integer second, the position of the previous moment and the carrier observation value of the current moment are used to recursively calculate the TDCP position of the master antenna and the slave antenna respectively to obtain the master and slave antenna positions at the current moment.

[0133] The recursive formula is:

[0134]

[0135] If it is not an integer second: use the position of the previous moment and the carrier observation value of the current moment to recursively deduce the TDCP position of the master antenna and the slave antenna respectively to obtain the master and slave antenna positions at the current moment.

[0136] The recursive formula is:

[0137]

[0138] After obtaining the positions of the master and slave antennas, according to the following formula

[0139]

[0140] Calculate the attitude angle (heading, pitch / roll angle) at the whole second.

[0141] The placement of the dual antennas and the carrier. If the direction of the dual antenna connection is parallel to the vehicle's forward direction, the calculated attitude is the heading angle and the pitch angle. If the direction of the dual antenna connection is perpendicular to the vehicle's forward direction,

[0142] The calculated attitude is the heading angle and the roll angle.

[0143] According to the present invention, dual-antenna TDCP positioning and orientation at non-integer second moments:

[0144] During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated.

[0145] Referring to formula (1), the carrier observation equation of satellite i to the main antenna at time t is listed as follows:

[0146]

[0147] Similarly, the carrier observation equation of satellite i to the main antenna at time t+1 is listed as follows:

[0148]

[0149] The difference between the two equations gives the TDCP observation equation:

[0150]

[0151] The solution for non-integer seconds is the difference between epochs, the difference between the carrier observation between the receiver and the satellite at the previous moment and the carrier observation between the receiver and the satellite at the current moment. It is because the ambiguity at adjacent moments remains unchanged that the difference is made to offset the ambiguity.

[0152] According to the present invention, the position at a non-integer second is obtained by recursive carrier observation. The accuracy of the carrier observation is at the millimeter level, which is very high. This recursive method is more dependent on the position accuracy of the previous moment. The present invention will use RTK to solve the position at the full second, which is equivalent to resetting the position to ensure that the error is small. The present invention has fixed ambiguity at the full second, and no fixed ambiguity at the non-integer second.

[0153] According to the present invention, in the dual-antenna TDCP positioning and orientation at non-integer seconds, the ionospheric delay, tropospheric delay and integer ambiguity are eliminated by inter-epoch difference, and the satellite clock error can be given by the ephemeris and deducted.

[0154] According to the present invention, and are the unit vectors pointing from the satellite to the receiver at epoch t and t+1 respectively. Considering that the speed of the satellite is much greater than the speed of the vehicle, and Can be approximately equal, so according to the geometric relationship:

[0155]

[0156] In the above formula, and are the satellite positions at epoch t+1 and t, respectively. and are the corresponding receiver positions, △r S and △r R are the geometric position increments of the satellite and the receiver in the Earth-centered Earth-fixed coordinate system (ECEF) between two epochs. Substituting them into the above formula, we can get:

[0157]

[0158] See Figure 1 The relationship between satellite and receiver, and are the unit vectors pointing from the satellite to the receiver at epoch t and t+1 respectively.

[0159] According to the present invention, multiple TDCP observations can be constructed to solve △r R , and then the master antenna position and slave antenna position at the current moment are obtained. According to step 1) (1-c), the attitude angle at the non-integer second moment can be solved.

[0160] According to the present invention, a GNSS dual-antenna orientation algorithm with full-second dual RTK solution and non-full-second TDCP solution is obtained, which realizes low computing power, low time consumption, high-frequency output, dynamic orientation, and high orientation accuracy of 0.15° / R (equivalent to the traditional dual-antenna orientation accuracy), where R is the baseline distance (meters). That is, the orientation accuracy of a 1-meter baseline is 0.15°; the orientation accuracy of a 2-meter baseline is 0.15 / 2=0.075°.

[0161] In addition, according to the present invention, the noise is small, the hardware requirement is low and no ambiguity fixing is required.

Claims

1. A low-computing GNSS dual-antenna orientation method, characterized in that: The method comprises: Step 1) Initialize and preprocess the dual-antenna observations, that is, remove gross errors and detect cycle slips to ensure the quality of GNSS observations. Step 2) Perform RTK positioning of the dual antenna positions at the full second to obtain the initial state. Repeat this step every full second to reset the positions of the dual antennas, including: Step 2-1) RTK positioning of the main antenna position at the whole second (2-1-a) Construct the single-difference carrier phase observation equation between the main antenna and the reference station. (2-1-b) Calculate the double-difference carrier phase observation equation, Step 2-2) RTK positioning from the antenna position at the whole second, If it is not an integer second, go to step 3): Step 3) Dual-antenna TDCP (time (epoch) differential carrier phase) positioning at non-integer seconds: Step 3-1) Perform TDCP positioning of the main antenna position at a non-integer second. (3-1-a) During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated. Step 3-2) TDCP positioning from the antenna position at a non-integer second, Step 4) Directional calculation of the master and slave antennas, Step 5) Output the directional results of the master and slave antennas.

2. A low-computing-power GNSS dual-antenna orientation method as claimed in claim 1, characterized in that: In step 2), (2-1-a) Construct the single-difference carrier phase observation equation of the main antenna and the reference station: The carrier phase measurement value of satellite i by main antenna u and reference station r and Can be expressed as Where, λ and f are the wavelength and frequency of the satellite signal (m and Hz respectively); are the distances from satellite i to the main antenna and reference station, respectively (m); I and T are the ionosphere and troposphere delays; δt u ,δt r They are the main antenna receiver delay and the base station receiver delay respectively; are the integer ambiguities from satellite i to the main antenna and the reference station respectively; are the observation noise of the carrier phase observation of the main antenna and the reference station, The difference between equation (1) and equation (2) gives the single-difference observation equation between stations and the single-difference carrier phase observation equation of satellite j for the main antenna and the reference station: For the short baseline system, the single difference ionospheric and tropospheric delays are approximately equal to 0, and equation (3) can be further simplified to: in: δt ur =δt u -δt r Similarly, the single-difference carrier phase observation equation of satellite j to the main antenna and reference station can be obtained:

3. A low-computing-power GNSS dual-antenna orientation method as claimed in claim 2, characterized in that: In step 2), (2-1-b) Calculate the double-difference carrier phase observation equation: The double difference observation equation can be obtained by subtracting equation (4) from equation (6) in: Further finishing includes: where b ur is the baseline vector, is the line of sight vector from satellite i to the receiver.

4. A low-computing-power GNSS dual-antenna orientation method as claimed in claim 3, characterized in that: In step 2-2) the RTK positioning from the antenna position at the full second, The baseline vector can be solved by equation (11). The main antenna position coordinates can be calculated when the base station position coordinates are known. At this point, the main antenna position has been obtained. The main antenna can be used as the "base station" and the slave antenna as the "mobile station". The slave antenna position coordinates can be calculated according to the above processes (2-1-a) and (2-1-b).

5. A low-computing-power GNSS dual-antenna orientation method as claimed in any one of claims 1 to 4, characterized in that: In step 3): (Step 3-1) Perform TDCP positioning of the main antenna position at a non-integer second, During the non-integer second period, TDCP is used to deliver the position, and then the attitude angle is calculated. Referring to formula (1), the carrier observation equation of satellite i to the main antenna at time t is listed as follows: Similarly, the carrier observation equation of satellite i to the main antenna at time t+1 is listed as follows: The difference between the two equations gives the TDCP observation equation:

6. A low-computing-power GNSS dual-antenna orientation method as claimed in claim 5, characterized in that: In step 3), dual-antenna TDCP (time (epoch) differential carrier phase) positioning at non-integer seconds: Step (3-1-b) performs TDCP positioning of the slave antenna position at a non-integer second. The TDCP positioning method of the slave antenna is the same as that of the main antenna.

7. A low-computing-power GNSS dual-antenna orientation method as claimed in claim 5, characterized in that: and are the unit vectors pointing from the satellite to the receiver at epoch t and t+1 respectively. Considering that the speed of the satellite is much greater than the speed of the vehicle, and Can be approximately equal, so according to the geometric relationship: In the above formula, and are the satellite positions at epoch t+1 and t, respectively. and are the corresponding receiver positions, △r S and △r R are the geometric position increments of the satellite and the receiver in the Earth-centered Earth-fixed coordinate system (ECEF) between two epochs. Substituting them into equation (14), we can obtain:

8. A low-computing-power GNSS dual-antenna orientation method as claimed in any one of claims 5 to 7, characterized in that: Constructing multiple formulas (16) TDCP observation equations can solve △r R , and then the main antenna position and the slave antenna position at the current moment are obtained.

9. A low-computing-power GNSS dual-antenna orientation method as described in any one of claims 3 or 4 or 5-7, characterized in that: Step 4) Directional calculation of the master and slave antennas: If it is not an integer second, use the position of the previous moment and the carrier observation value of the current moment to perform TDCP position recursion on the master antenna and the slave antenna respectively to obtain the master and slave antenna positions at the current moment. The recursive formula is: Using the main antenna, the main antenna is pointed from the antenna coordinates. The projection of the slave antenna vector in the NED coordinate system is recorded as Then there are heading angle and pitch angle (or roll angle):

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