A system and detection method for obtaining antenna phase center data

Abstract

The present invention discloses a system and detection method for obtaining antenna phase center data, which relates to the field of data measurement technology, including a signal recording module, a signal playback module, a waveform recording module, a GNSS simulator and a central controller; the central controller uses a communication method to communicate with the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator; the information processed by the signal recording module is transmitted to the signal playback module, the GNSS simulator and the central controller; after the signal playback module receives the information transmitted by the signal recording module, the received information is transmitted to the waveform recording module through the central controller. The present invention is aimed at the change of the antenna phase center caused by the change of the GNSS antenna's own attitude causing the change of its own input signal strength, the change of the altitude angle, and the change of the distribution position and orientation of the sky satellites, and can be the effect of changing the test items and ranges without knowing the angle of the test site in advance.

Description

Technical Field

[0001] The present invention relates to the technical field of data measurement, and in particular to a system and a detection method for acquiring antenna phase center data. Background Art

[0002] The antenna phase center refers to the position of the equivalent point source of the antenna's electromagnetic radiation. If the antenna radiates a spherical isophase surface, then the center of the sphere is its phase center. In theory, the electrical center of the receiver antenna should be consistent with the geometric center of the antenna, but in reality, due to the antenna material production process and processing and installation errors, there is an unavoidable deviation between the antenna's phase center and its geometric center.

[0003] Chinese patent CN109814133A discloses a GNSS receiver tilt measurement system and method, the system includes: an inertial measurement unit, a GNSS receiver, a processor and a centering rod; the inertial measurement unit is used to measure the first attitude information of the GNSS receiver; the GNSS receiver is used to measure the first position information; the processor is used to use the inertial navigation mechanical arrangement algorithm and the Kalman filter algorithm to solve the second position information and the second attitude information according to the received data. The technical solution of the embodiment of the present invention obtains attitude information and position information respectively through the inertial measurement unit and the GNSS receiver, uses the inertial navigation mechanical arrangement algorithm to calculate the position, speed and attitude of the GNSS receiver, and uses the Kalman filter algorithm to calculate the measurement error feedback to correct the above-mentioned calculation result. Although the patent combines the measurement factor of attitude, the patent only discloses the tilt measurement of multiple spatial points, and there is still a deviation problem between the antenna phase center and its geometric center caused by installation errors and other reasons.

[0004] Chinese patent CN111381256A provides a method and system for calculating the phase center offset error of an active remote sensing satellite antenna. The vector of the satellite GNSS antenna phase center in the WGS84 coordinate system is obtained by processing GNSS observation data, and the error includes the measurement error of GNSS; the line vector between the GNSS antenna phase center and the active remote sensing antenna phase center in the satellite body coordinate system is obtained based on ground measurement, and the error includes the installation and deformation error of the GNSS antenna and the active remote sensing antenna phase center; the coordinate transformation matrix from the satellite body coordinate system to the WGS84 coordinate system is calculated, and the error includes the satellite attitude pointing error, the GNSS measurement error, and the orbit parameter conversion error; the vector and offset error of the satellite active remote sensing antenna phase center in the WGS84 coordinate system are calculated. However, this patent needs to consider factors such as the angle change of ground measurement, and the operation is too complicated. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a system and a detection method for acquiring antenna phase center data.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is as follows:

[0007] A system for acquiring antenna phase center data, comprising a signal recording module, a signal playback module, a waveform recording module, a GNSS simulator and a central controller;

[0008] The central controller is connected to the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator by communication, and the central controller is used to provide and control the operating environment of the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator;

[0009] The information processed by the signal recording module is transmitted to the signal playback module, the GNSS simulator and the central controller; after the signal playback module receives the information transmitted by the signal recording module, the received information is transmitted to the waveform recording module through the central controller; the waveform recording module is used to record the positioning information, time information, spread spectrum waveform and carrier phase information provided by the satellite signal.

[0010] Furthermore, the signal recording module receives and records satellite signals through an antenna, and the signal playback module transmits the information recorded by the signal recording module to the GNSS simulator, and the GNSS simulator calculates and obtains positioning information and uses it to convert pseudorange values.

[0011] Furthermore, the central controller is communicatively connected to an external mobile device, and the external mobile device controls the execution of the central controller.

[0012] Furthermore, the signal recording module, the signal playback module, the waveform recording module, the GNSS simulator and the central controller maintain clock synchronization.

[0013] Furthermore, the signal recording module includes a multi-channel signal recording module and a differential information recording module, and the signal recording module is a radio frequency signal input device with a frequency below 6 GHz.

[0014] Furthermore, the frequency band of the signal recorded by the multi-channel signal recording module is in the range of 1.1GHz-3.0GHz, and the bandwidth is in the range of 1MHz-80MHz; the frequency band of the signal recorded by the differential information recording module is in the range of 0.8GHz-6GHz, and the bandwidth is 1MHz-200MHz.

[0015] Furthermore, the signal playback module is a radio frequency signal output device with a frequency below 6 GHz, including a multi-channel signal playback module and a differential information playback module. The multi-channel signal playback module uses the signal stored in the satellite signal recording module as a reference signal for static parameters and dynamic parameters.

[0016] Furthermore, the signal recording module records the on-site signal, including the satellite serial number, satellite constellation distribution and the carrier noise density of each serial numbered satellite, and the recorded frequency points include at least GPS-L1 and BDS-B1.

[0017] Furthermore, the operating environment includes at least set working modes, parameter settings, input and output execution and data recording.

[0018] A detection method for obtaining antenna phase center data system, the steps comprising:

[0019] Step S1: The signal playback module transmits the signal collected by the signal recording module to the waveform recording module through the antenna. At this time, the phase τ1 is:

[0020]

[0021] Where f is the carrier frequency, c is the speed of light, l i is the pseudorange value, P i is the antenna phase center offset, t i is the clock difference between the waveform recording module and the satellite, Q i is the multipath error, ρ T is the tropospheric error, ρ I is the ionospheric error, N i is the integer ambiguity, t r It is the hardware delay error of the waveform recording module;

[0022] Step S2: The GNSS simulator performs simulation based on the actual satellite signal parameters transmitted by the signal playback module. The simulated signal completes a self-loop internally. At this time, the standard phase value τ0 is:

[0023]

[0024] Step S3: The simulation signal of the GNSS simulator is directly transmitted to the waveform recording module without passing through the antenna. At this time, the phase τ2 is:

[0025]

[0026] Step S4: The simulation signal of the GNSS simulator passes through the stationary antenna to the waveform recording module, and the phase τ3 is:

[0027]

[0028] Where δ is the antenna phase center deviation;

[0029] Step S5: The GNSS simulator changes the angle of each satellite number and outputs a simulated signal through the antenna to the waveform recording module. At this time, the phase τ θ The dependent variable is only θ i , the relationship between antenna phase and attitude change angle is obtained:

[0030]

[0031] Step S6: Combine step S1 to make a judgment and select τ θ <τ1 when τ θ With θ i The data form a data set;

[0032] Step S7: Complete the antenna phase center change test at each angle.

[0033] Compared with the prior art, the beneficial effects of the present invention are specifically embodied in:

[0034] (1) The present invention aims at the change of the antenna phase center caused by the change of the GNSS antenna's own posture causing the change of its own input signal strength and altitude angle, as well as the change of the distribution position and orientation of the satellites in the sky. It can change the test items and range without knowing the angle of the test site in advance, and has a wider applicability.

[0035] (2) The signal recording module in the present invention receives and records the actual satellite signal through the antenna; the signal playback module sends the actual satellite signal to the waveform recording module and the GNSS simulator at the same time; the GNSS simulator outputs the error-eliminated signal to the waveform recording module based on the recorded information (satellite number, satellite angle, satellite time, etc.). The waveform recording module eliminates the clock error, multipath error, tropospheric error, ionospheric error and other error components and integer ambiguity between the receiving device and the satellite by comparing the two input signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose and technical solution of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with embodiments.

[0038] Example 1

[0039] like Figure 1A system for obtaining antenna phase center data is shown, including a signal recording module, a signal playback module, a waveform recording module, a GNSS simulator and a central controller; the central controller uses a communication method to communicate with the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator, and the central controller is used to provide and control the operating environment and parameters of the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator, and maintain clock synchronization, and is used to align the phase information of each time domain related signal, and can obtain the corresponding changed antenna phase center by changing the antenna posture. Here, the central controller can be regarded as a computer with an operating system / software, supporting remote operation of mobile devices, and other hardware such as signal recording modules, signal playback modules, waveform recording modules and GNSS simulators need to be driven by the central controller to set the working mode and specific parameters, and complete input / output, data recording and other functions.

[0040] The information processed by the signal recording module is transmitted to the signal playback module, the GNSS simulator and the central controller; after the signal playback module receives the information transmitted by the signal recording module, it transmits the received information to the waveform recording module through the central controller, that is, the signal recording module and the signal playback module are used to record satellite signals, satellite angles and satellite time in the actual environment. Specifically, the satellite angle refers to the angle between the satellite and the antenna. Since the real satellite in orbit can be regarded as stationary relative to the ground where the antenna is located, the satellite angle can only be changed by changing the attitude of the antenna. Here, according to the principle of relative motion, a GNSS simulator is set to directly change the satellite angle. At this time, the antenna can achieve the effect of attitude change in the actual static state. And the positioning signal and differential signal can provide corresponding information to the waveform recording module and the GNSS simulator through the central controller; the waveform recording module is used to record the positioning information, time information, spread spectrum waveform and carrier phase information provided by the satellite signal.

[0041] The signal recording module receives and records satellite signals through an antenna, and the signal playback module transmits the information recorded by the signal recording module to the GNSS simulator. The GNSS simulator calculates and obtains positioning information and is used to convert pseudo-range values. The GNSS simulator sets the constellation diagram of the broadcast signal according to the fixed satellite number sequence, and outputs it to the waveform recording module after direct transmission self-loop measurement. Specifically, the GNSS simulator outputs the clock difference, multipath error, tropospheric error, ionosphere error and other error components and integer ambiguity between the receiving device and the satellite according to the recorded information, such as satellite number, satellite angle, satellite time, etc., and does not pass other transmission methods to its own recording unit, and then outputs it to the waveform recording module. In this way, the hardware delay error generated by the waveform recording module can be eliminated. The central controller is connected to the external mobile device for communication, and the external mobile device controls the execution of the central controller, and the operation status of the satellite signal recording module, signal playback module, GNSS simulator, waveform recording module and other equipment is set by the central controller.

[0042] The signal playback module is a radio frequency signal output device with a frequency below 6 GHz, including a multi-channel signal playback module and a differential information playback module. The multi-channel signal playback module extracts the constellation signal and positioning or timing data stored in the satellite signal recording module as reference signals for static parameters and dynamic parameters such as position, length, speed and acceleration.

[0043] The signal recording module is a radio frequency signal input device with a frequency below 6 GHz, including a multi-channel signal recording module and a differential information recording module. The multi-channel signal recording module records signals with a frequency band range of 1.1 GHz-3.0 GHz and a bandwidth range of 1 MHz-80 MHz; the differential information recording module records signals with a frequency band of 0.8 GHz-6 GHz and a bandwidth of 1 MHz-200 MHz. The signal recording module is used to record field signals, including information such as satellite signals, satellite angles, and satellite time. The recorded frequencies include at least GPS-L1 and BDS-B1. The waveform recording module sets a single-frequency differential working mode, and records data in combination with the phase center deviation of each antenna to obtain a data set of antenna phase center changes with angle. Environmental errors, errors in the receiving device itself, and changes in antenna attitude will all cause the phase value τ i Changes occurred:

[0044]

[0045] Where f is the carrier frequency, c is the speed of light, l i is the pseudorange value, P i is the antenna phase center offset, t i is the clock difference between the waveform recording module and the satellite, Q i is the multipath error, the tropospheric error ρT and the ionospheric error ρ I , N i is the integer ambiguity, t r is the hardware delay error of the waveform recording module, δ is the correction coefficient of the antenna phase center deviation, and θ i is the current angle value.

[0046] Combined with Figure 1 ,In order to distinguish the changes caused by posture, the system working principle includes the following steps:

[0047] Step S1: The signal playback module transmits the signal collected by the signal recording module to the waveform recording module through the antenna. At this time, the phase τ1 includes the external error, the waveform recording module error and the antenna phase offset.

[0048]

[0049] Step S2: The GNSS simulator performs simulation based on the actual satellite signal parameters (satellite number, satellite angle, satellite time, etc.) transmitted by the signal playback module. The simulation signal completes a self-loop internally. At this time, the standard phase value τ0 only contains the pseudorange value (directly converted from the positioning information) and the system noise ε (an empirical constant unrelated to the sample to be tested).

[0050]

[0051] Step S3: The simulation signal of the GNSS simulator is directly transmitted to the waveform recording module without passing through the antenna. At this time, the phase τ2 includes the internal delay error of the waveform recording module. The internal delay error of the module can be obtained by combining S2, and the waveform recording module can be directly reset to zero to compensate and eliminate the error.

[0052]

[0053] Step S4: The simulation signal of the GNSS simulator passes through the stationary antenna to the waveform recording module. At this time, the phase τ3 includes the internal delay error of the waveform recording module and the antenna phase center deviation. Since the internal delay error of the waveform recording module has been compensated and eliminated, τ3 is expressed as:

[0054]

[0055] Combined with step S2, the antenna phase center deviation δ is obtained as the antenna phase center deviation correction coefficient.

[0056] Step S5: The GNSS simulator changes the angle of each satellite number (simulating the relative attitude change of the antenna) and outputs a simulation signal through the antenna to the waveform recording module. At this time, the phase τ θ After the above steps, the dependent variable is only θ i, the relationship between antenna phase and attitude change angle is obtained:

[0057]

[0058] If the waveform recording module accuracy is higher than the GNSS simulator accuracy, τ θ It can also be expressed as:

[0059] τ θ =τ0+δ+θ i

[0060] Step S6: Combine step S1 to make a judgment and select τ θ <τ1 when τ θ With θ i The data forms a data set.

[0061] Step S7: Complete the antenna phase center change test at each angle.

[0062] The actual application is in the scenario of "testing the motion posture of a small vehicle through the relationship between the antenna phase center and the posture", which includes various errors. Therefore, in this application scenario, determining the independent variables caused by the posture requires stripping off various errors to avoid repeated influences.

[0063] The above is only an embodiment of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A system for obtaining antenna phase center data, characterized in that: Including signal recording module, signal playback module, waveform recording module, GNSS simulator and central controller; The central controller is connected to the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator by communication, and the central controller is used to provide and control the operating environment of the signal recording module, the signal playback module, the waveform recording module and the GNSS simulator; maintain clock synchronization, and is used to align the phase information of each time domain related signal, and can obtain the corresponding antenna phase center by changing the antenna posture; The information processed by the signal recording module is transmitted to the signal playback module, the GNSS simulator and the central controller; After receiving the information transmitted by the signal recording module, the signal playback module transmits the received information to the waveform recording module through the central controller; The waveform recording module is used to record the positioning information, time information, spread spectrum waveform and carrier phase information provided by the satellite signal.

2. A system for obtaining antenna phase center data according to claim 1, characterized in that: The signal recording module receives and records satellite signals through an antenna, and the signal playback module transmits the information recorded by the signal recording module to the GNSS simulator. The GNSS simulator calculates and obtains positioning information and uses it to convert pseudorange values.

3. A system for obtaining antenna phase center data according to claim 1, characterized in that: The central controller is in communication connection with the external mobile device, and the external mobile device controls the execution of the central controller.

4. A system for obtaining antenna phase center data according to claim 1, characterized in that: The signal recording module, the signal playback module, the waveform recording module, the GNSS simulator and the central controller maintain clock synchronization.

5. The system for obtaining antenna phase center data according to claim 1, characterized in that: The signal recording module includes a multi-channel signal recording module and a differential information recording module, and the signal recording module is a radio frequency signal input device with a frequency below 6 GHz.

6. A system for obtaining antenna phase center data according to claim 5, characterized in that: The frequency band of the signal recorded by the multi-channel signal recording module is in the range of 1.1GHz-3.0GHz, and the bandwidth is in the range of 1MHz-80MHz; the frequency band of the signal recorded by the differential information recording module is in the range of 0.8GHz-6GHz, and the bandwidth is 1MHz-200MHz.

7. The system for obtaining antenna phase center data according to claim 1, characterized in that: The signal playback module is a radio frequency signal output device with a frequency below 6 GHz, including a multi-channel signal playback module and a differential information playback module. The multi-channel signal playback module uses the signal stored in the satellite signal recording module as a reference signal for static parameters and dynamic parameters.

8. The system for obtaining antenna phase center data according to claim 1, characterized in that: The signal recording module records the on-site signal, including the satellite serial number, satellite constellation distribution and the carrier noise density of each serial numbered satellite, and the recorded frequency points include at least GPS-L1 and BDS-B1.

9. The system for obtaining antenna phase center data according to claim 1, characterized in that: The operating environment at least includes the set working mode, parameter setting, input and output execution and data recording.

10. A detection method for obtaining antenna phase center data system, characterized in that: A system for obtaining antenna phase center data as described in any one of claims 1 to 9, comprising the steps of: Step S1: The signal playback module transmits the signal collected by the signal recording module to the waveform recording module through the antenna. At this time, the phase τ1 is: Where f is the carrier frequency, c is the speed of light, l i is the pseudorange value, P i is the antenna phase center offset, t i is the clock difference between the waveform recording module and the satellite, Q i is the multipath error, ρ T is the tropospheric error, ρ I is the ionospheric error, N i is the integer ambiguity, t r It is the hardware delay error of the waveform recording module; Step S2: The GNSS simulator simulates the actual satellite signal parameters transmitted by the signal playback module, and the simulated signal completes a self-loop. At this time, the standard phase value τ0 is: Step S3: The simulation signal of the GNSS simulator is directly transmitted to the waveform recording module without passing through the antenna. At this time, the phase τ2 is: Step S4: The simulation signal of the GNSS simulator passes through the stationary antenna to the waveform recording module, and the phase τ3 is: Where δ is the antenna phase center deviation; Step S5: The GNSS simulator changes the angle of each satellite number and outputs a simulated signal through the antenna to the waveform recording module. At this time, the phase τ θ The dependent variable is only θ i , the relationship between antenna phase and attitude change angle is obtained: Step S6: Combine step S1 to make a judgment and select τ θ <τ1 when τ θ With θ i The data form a data set; Step S7: Complete the antenna phase center change test at each angle.

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