Dual-antenna GNSS-IR water level monitoring method, device, equipment and storage medium

Abstract

This invention discloses a dual-antenna GNSS-IR water level monitoring method, apparatus, device, and storage medium, relating to the field of water level measurement technology. The method involves placing a first antenna below a second antenna and using a dual-antenna receiver to receive the signal-to-noise ratio (SNR) sequences of both the first and second antennas. Based on the antenna spacing, the antenna interference phase difference is calculated. Based on the antenna interference phase difference, the interference phase of the target antenna is calculated. Based on the oscillation frequency and wavelength of the SNR sequences, the interference phase, the GNSS satellite elevation angle, and the absolute antenna altitude, the absolute altitude of the target water surface is calculated. Compared to existing technologies, this invention solves the problem of low sampling rate in traditional single-antenna GNSS-IR altimeter measurement. Furthermore, compared to dual-antenna GNSS-IR, this invention offers more stable signal tracking and lower hardware costs.

Description

Technical Field

[0001] This invention relates to the field of water level measurement technology, and in particular to a dual-antenna GNSS-IR water level monitoring method, apparatus, equipment, and storage medium. Background Technology

[0002] To achieve all-weather operation, GNSS (Global Navigation Satellite System) has deployed hundreds of satellites, creating numerous radiation sources. GNSS signals use the L-band, which is highly sensitive to moisture. Based on this characteristic, using GNSS reflected signals for sea surface altimetry enables all-weather operation capabilities that are unattainable with traditional altimetry methods.

[0003] Single-antenna GNSS-IR (Global Navigation Satellite System Interferometric Reflectometry) technology is a technique for measuring sea surface height using GNSS reflected signals. It calculates sea surface height by using the interferometric sequence generated by the observed sea surface reflected signals and direct signals at low elevation angles. This method requires at least 20 minutes of observation sequence to obtain a sea surface height measurement result, and the output frequency is low, making it difficult to meet the real-time measurement needs in complex marine environments. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-antenna GNSS-IR water level monitoring method, apparatus, equipment, and storage medium, which can improve the real-time performance of water level monitoring.

[0005] To achieve the above objectives, embodiments of the present invention provide a dual-antenna GNSS-IR water level monitoring method, comprising: The first antenna is positioned below the second antenna, and a dual-antenna receiver is used to receive the signal-to-noise ratio sequences of the first antenna and the second antenna, respectively. Calculate the antenna interference phase difference based on the antenna spacing; Based on the antenna interference phase difference, the interference phase of the target antenna is calculated; The absolute height of the target water surface is calculated based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the absolute antenna height.

[0006] As an improvement to the above scheme, the antenna interference phase difference is calculated using the following formula:

[0007] in, Indicates the phase difference of antenna interference; express GNSS satellite elevation angle at a given time; Indicates the antenna spacing; The wavelength representing the signal-to-noise ratio sequence; Represents pi; This represents the sine function.

[0008] As an improvement to the above scheme, if the target antenna is a first antenna, then the interference phase of the target antenna is calculated using the following formula:

[0009] in, Indicates the interference phase of the first ray; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0010] As an improvement to the above scheme, if the target antenna is a second antenna, then the interference phase of the target antenna is calculated using the following formula:

[0011] in, Indicates the interference phase of the second antenna; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0012] As an improvement to the above scheme, the calculation of the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interferometric phase, the GNSS satellite elevation angle, and the antenna absolute height includes: Based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, calculate the estimated vertical height of the antenna; Based on the antenna vertical height estimate, the wavelength, and the GNSS satellite elevation angle, calculate the integer ambiguity; Based on the integer ambiguity, the wavelength, and the interference phase, the carrier phase path delay of the target antenna is calculated; The vertical altitude of the target antenna is calculated based on the carrier phase path delay and the GNSS satellite elevation angle. Based on the vertical height and the absolute height of the antenna, the absolute height of the target water surface is calculated.

[0013] As an improvement to the above scheme, when the absolute height of the antenna is the absolute height of the target antenna, the step of calculating the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: Subtract the vertical height from the absolute height of the antenna to obtain the absolute height of the target water surface.

[0014] As an improvement to the above scheme, when the absolute height of the antenna is the same as the absolute height of another antenna, the calculation of the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: The absolute height of the target water surface is obtained by subtracting the vertical height from the absolute height of the antenna and adding or subtracting the antenna spacing.

[0015] To achieve the above objectives, embodiments of the present invention also provide a dual-antenna GNSS-IR water level monitoring device, comprising: The signal input module is used to set the first antenna below the second antenna and to use a dual-antenna receiver to receive the signal-to-noise ratio sequences of the first antenna and the second antenna, respectively. The interference phase difference calculation module is used to calculate the antenna interference phase difference based on the antenna spacing. The interference phase calculation module is used to calculate the interference phase of the target antenna based on the interference phase difference of the antenna. The water level calculation module is used to calculate the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the absolute height of the antenna.

[0016] To achieve the above objectives, embodiments of the present invention also provide a dual-antenna GNSS-IR water level monitoring device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the dual-antenna GNSS-IR water level monitoring method as described in any of the above embodiments.

[0017] To achieve the above objectives, embodiments of the present invention also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the dual-antenna GNSS-IR water level monitoring method as described in any of the above embodiments.

[0018] Compared with existing technologies, the dual-antenna GNSS-IR water level monitoring method, apparatus, device, and storage medium provided in this invention place the first antenna below the second antenna and use a dual-antenna receiver to receive the signal-to-noise ratio (SNR) sequences of the first and second antennas respectively; calculate the antenna interference phase difference based on the antenna spacing; calculate the interference phase of the target antenna based on the antenna interference phase difference; and calculate the absolute height of the target water surface based on the oscillation frequency and wavelength of the SNR sequence, the interference phase, the GNSS satellite elevation angle, and the absolute antenna height. Compared with existing technologies, this invention can solve the problem of low sampling rate in traditional single-antenna GNSS-IR altimeter measurement, and compared with dual-antenna GNSS-IR, the signal tracking of this invention is more stable and the hardware cost is lower. Attached Figure Description

[0019] Figure 1 This is a flowchart of a dual-antenna GNSS-IR water level monitoring method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a dual-antenna GNSS-IR water level monitoring method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a dual-antenna GNSS-IR water level monitoring device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a dual-antenna GNSS-IR water level monitoring device provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] It is worth noting that dual-antenna GNSS-R (Global Navigation Satellite System Reflectometry) technology is also an existing method for sea surface height measurement. It uses two antennas: a direct antenna to provide direct path information (right-hand polarization) and a reflective antenna to provide reflection path information (left-hand polarization). The sea surface height is calculated by subtracting the path difference between the two observations.

[0025] Dual-antenna GNSS-R typically uses a specially designed left-handed polarized antenna to collect GNSS signals reflected from the water surface. The receiver must either be a custom-made receiver or two traditional receivers. For the former, the cost of a custom-made receiver is high, which is not conducive to its widespread application. For the latter, the tracking error of the reflected signal is large, the operation is unstable, and in marine environments, it is even impossible to obtain effective path delay observations of the reflected signal.

[0026] Compared with existing technologies, the dual-antenna GNSS-IR water level measurement method provided by the present invention can solve the above-mentioned drawbacks of dual-antenna GNSS-R and single-antenna GNSS-IR.

[0027] It is worth noting that this invention can be used not only for measuring sea level height, but also for measuring water level height in open water bodies such as rivers, reservoirs and lakes, without limitation.

[0028] To facilitate explanation, some terms in this invention will be explained below. In this invention, the first antenna refers to the lower antenna in a dual antenna configuration, and the second antenna refers to the upper antenna in a dual antenna configuration. Absolute height refers to the height above the ground, and vertical height refers to the height above the water surface.

[0029] Furthermore, for ease of description, this invention refers to the signal-to-noise ratio (SNR) sequence of the first antenna as the "first SNR sequence", the SNR sequence of the second antenna as the "second SNR sequence", the detrended SNR sequence of the first antenna as the "first detrended SNR sequence", the detrended SNR sequence of the second antenna as the "second detrended SNR sequence", the interference phase of the first antenna as the "first interference phase", the interference phase of the second antenna as the "second interference phase", and the difference between the first interference phase and the second interference phase as the "antenna interference phase difference".

[0030] See Figure 1 This is a flowchart of a dual-antenna GNSS-IR water level monitoring method provided in an embodiment of the present invention, including steps S1 to S4: S1. The first antenna is set below the second antenna, and a dual-antenna receiver is used to receive the signal-to-noise ratio sequences of the first antenna and the second antenna, respectively. S2. Calculate the antenna interference phase difference based on the antenna spacing; S3. Calculate the interference phase of the target antenna based on the antenna interference phase difference; S4. Calculate the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the absolute height of the antenna.

[0031] Understandably, in GNSS-IR, it is necessary to observe the interferometric sequence to obtain the interferometric phase in order to determine the vertical height of the antenna and then calculate the water level. However, due to the long observation time of the interferometric sequence, the water level output frequency of GNSS-IR is low. To overcome this deficiency, this invention uses dual antennas, which can utilize the geometric difference in the height measurements of the upper and lower antennas to calculate the antenna interferometric phase difference, and then calculate the interferometric phase for calculating the water level.

[0032] Furthermore, although the present invention uses two antennas, the water level can be calculated by measuring the vertical distance of one of the antennas. For ease of distinction, the present invention refers to the antenna used for vertical distance calculation as the "target antenna" and the other antenna as the "other antenna".

[0033] Specifically, see Figure 2 This is a schematic diagram of a dual-antenna GNSS-IR water level monitoring method according to an embodiment of the present invention. In this invention, the first and second antennas are arranged vertically and identically, both being right-handed polarized. Furthermore, the dual antennas are used to acquire GNSS interference signals between direct and reflected signals. Figure 2 In the diagram, d represents the antenna spacing, H2 represents the absolute altitude of the second antenna (relative to the reference ellipsoid), h1 represents the vertical altitude of the first antenna, and h2 represents the vertical altitude of the second antenna. The elevation angle of the GNSS satellite is represented by SSH, and the absolute elevation of the target water surface is represented by SSH.

[0034] Furthermore, in this invention, a dual-antenna receiver is used to record observation files for the first and second antennas respectively, and the observation files adopt the standard observation file (RINEX) format. Compared with dual-antenna GNSS-R, the receiver of this invention only needs to track the direct GNSS signal; therefore, existing dual-antenna GNSS boards can be used, resulting in low cost and stable tracking.

[0035] Further, in step S2, the antenna interference phase difference is calculated based on the antenna spacing, and the calculation model is as follows (7); in step S3, the interference phase of the target antenna is calculated based on the antenna interference phase difference. When the target antenna is the first antenna, the calculation model is as follows (12), and when the target antenna is the second antenna, the calculation model is as follows (17); finally, in step S4, the absolute height of the target water surface is calculated based on the interference phase of the target antenna.

[0036] Compared to single-antenna GNSS-IR, this invention utilizes the geometrical difference in elevation measurement between the upper and lower antennas to extract the interference phase, enabling the output frequency of water level measurement results to reach the second level, meeting the water level measurement requirements of complex water areas. Compared to dual-antenna GNSS-R, this invention eliminates the need to track reflected signals, reducing receiver costs. Compared to existing technologies, this invention balances real-time performance and cost-effectiveness in water level measurement, exhibiting greater practicality.

[0037] Furthermore, the derivation process of the antenna interference phase difference calculation model and the interference phase calculation model of the present invention will be introduced below.

[0038] For example, in step S1, the satellite elevation angle and azimuth angle range are set according to the experimental scenario, and the first signal-to-noise ratio sequence and the second signal-to-noise ratio sequence are extracted, as shown in equation (1) and equation (2) respectively: For example, the first signal-to-noise ratio sequence is as follows: (1) in, Indicates the first signal-to-noise ratio sequence; Indicates the amplitude of the direct signal; Indicates the amplitude of the reflected signal; Indicates noise power; This represents the first interference phase, which is the interference phase between the direct GNSS signal and the reflected signal acquired by the first antenna; This represents the cosine function.

[0039] For example, the second signal-to-noise ratio sequence is as follows: (2) in, Indicates the second signal-to-noise ratio sequence; Indicates the amplitude of the direct signal; Indicates the amplitude of the reflected signal; Indicates noise power; This represents the second interference phase, which is the interference phase between the direct and reflected GNSS signals acquired by the second antenna. This represents the cosine function.

[0040] It is worth noting that since the present invention uses the same type of antenna to receive signals and the receiver is a dual-antenna receiver, the received power of different antenna signals is approximately equal. That is, in the first signal-to-noise ratio sequence and the second signal-to-noise ratio sequence, the amplitude of the direct signal, the amplitude of the reflected signal, and the noise are approximately equal.

[0041] Furthermore, by using a quadratic polynomial fitting method to remove the trend terms of the first and second signal-to-noise ratio sequences, equations (3) and (4) are obtained: (3) in, This represents the first detrended signal-to-noise ratio sequence; Represents the coefficients of the detrended signal-to-noise ratio sequence, and , Indicates the amplitude of the direct signal; Indicates the amplitude of the reflected signal; Indicates noise power; Indicates the first interference phase; This represents the cosine function.

[0042] (4) in, This represents the second detrended signal-to-noise ratio sequence; Represents the coefficients of the detrended signal-to-noise ratio sequence, and , Indicates the amplitude of the direct signal; Indicates the amplitude of the reflected signal; Indicates noise power; Indicates the second interference phase; This represents the cosine function.

[0043] Furthermore, based on the GNSS-IR principle, the relationship between the interference phase and the antenna's vertical height can be obtained, as shown in equations (5) and (6): (5) in, express The first interference phase at time; express The vertical height of the first line at any given time, that is... The height of the first antenna above the water surface at any given moment; express GNSS satellite elevation angle at a given time; The wavelength representing the signal-to-noise ratio sequence; Represents pi; This represents the sine function.

[0044] (6) in, express The second interference phase at time; express The vertical height of the second line at any given time, that is... The height of the second horizon above the water surface at any given moment; express GNSS satellite elevation angle at a given time; The wavelength representing the signal-to-noise ratio sequence; Represents pi; This represents the sine function.

[0045] Furthermore, subtracting equations (5) and (6) yields the antenna interference phase difference calculation model. As one optional implementation, the antenna interference phase difference is calculated using the following equation: (7) in, This represents the phase difference of antenna interference, and , express The first interference phase at time , express The second interference phase at time; express The GNSS satellite elevation angle at any given time can be obtained through GNSS positioning and ephemeris files; Indicates the antenna spacing, and , express The vertical height of the first line at any given time. express The vertical height of the second horizon at any given moment; The wavelength representing the signal-to-noise ratio sequence; Represents pi; This represents the sine function.

[0046] For example, GNSS satellite elevation angle The satellite's xyz coordinates are obtained by converting them into the receiver's station-centered coordinate system (ENU coordinates) using Euler angle rotation. Then, the satellite's elevation and azimuth angles in the station-centered coordinate system are calculated using the elevation and azimuth angle formulas.

[0047] It is worth noting that the interferometric phase calculation model for the first antenna is slightly different from that for the second antenna. The derivation process of the interferometric phase calculation model for the first antenna will be introduced below.

[0048] First, based on the antenna interference phase difference, the expression for the second interference phase can be obtained as follows: (8) in, express The second interference phase at time; express The first interference phase at time; This indicates the phase difference of antenna interference.

[0049] Substituting equation (8) into equation (4), we can obtain another expression for the second detrended signal-to-noise ratio sequence as follows: (9) in, This represents the second detrended signal-to-noise ratio sequence; The coefficients represent the detrended signal-to-noise ratio sequence; express The first interference phase at time; Indicates the phase difference of antenna interference; This represents the cosine function.

[0050] Using the expansion of the cosine and angle formulas (9), and using Alternative The sine value of the first interference phase can be obtained by rearranging the equation as follows: (10) in, Indicates the first interference phase The sine value; This represents the first detrended signal-to-noise ratio sequence; This represents the second detrended signal-to-noise ratio sequence; The coefficients represent the detrended signal-to-noise ratio sequence; Indicates the phase difference of antenna interference; Represents the sine function; This represents the cosine function.

[0051] It is understandable that the first interference phase can be obtained by rearranging equation (3). The cosine value is as follows: (11) in, Indicates the first interference phase The cosine value; This represents the first detrended signal-to-noise ratio sequence; This represents the detrended signal-to-noise ratio sequence coefficients.

[0052] Furthermore, by dividing both sides of equations (10) and (11) respectively, we can obtain the tangent value of the first interference phase. Then, by taking the arctangent, we can obtain the first interference phase as shown in the following equation: (12) in, Indicates the interference phase of the first ray; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0053] It is understandable that Equation (12) is the interference phase calculation model of the first antenna. In step S3, when the target antenna is the first antenna, the antenna interference phase is calculated according to Equation (12).

[0054] As one optional implementation, if the target antenna is a first antenna, then the interference phase of the target antenna is calculated using the following formula: (12) in, Indicates the interference phase of the first ray; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0055] Furthermore, the derivation process of the interference phase calculation model for the second antenna is similar to that for the first antenna. First, based on the antenna interference phase difference, the expression for the first interference phase can be obtained as follows: (13) in, express The first interference phase at time; express The second interference phase at time; This indicates the phase difference of antenna interference.

[0056] Substituting equation (13) into equation (3), we can obtain another expression for the first detrended signal-to-noise ratio sequence as follows: (14) in, This represents the first detrended signal-to-noise ratio sequence; The coefficients represent the detrended signal-to-noise ratio sequence; Indicates the second interference phase; Indicates the phase difference of antenna interference; This represents the cosine function.

[0057] The cosine difference angle formula is expanded as (14), and then... Alternative The sine value of the second interference phase can be obtained by rearranging the equation as follows: (15) in, Indicates the second interference phase The sine value; This represents the first detrended signal-to-noise ratio sequence; This represents the second detrended signal-to-noise ratio sequence; The coefficients represent the detrended signal-to-noise ratio sequence; Indicates the phase difference of antenna interference; Represents the sine function; This represents the cosine function.

[0058] It is understandable that the second interference phase can be obtained by rearranging equation (4). The cosine value is as follows: (16) in, Indicates the second interference phase The cosine value; This represents the second detrended signal-to-noise ratio sequence; The coefficients represent the detrended signal-to-noise ratio sequence; Furthermore, by dividing both sides of equations (15) and (16) respectively, we can obtain the tangent value of the second interference phase. Then, by taking the arctangent, we can obtain the second interference phase as shown in the following equation: (17) in, Indicates the interference phase of the second antenna; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0059] It is understandable that Equation (17) is the interference phase calculation model for the second antenna. In step S3, when the target antenna is the second antenna, the antenna interference phase is calculated according to Equation (17).

[0060] As one optional implementation, if the target antenna is a second antenna, then the interference phase of the target antenna is calculated using the following formula: (17) in, Indicates the interference phase of the second antenna; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

[0061] As one optional implementation, in step S4, calculating the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the antenna absolute height includes: Based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, calculate the estimated vertical height of the antenna; Based on the antenna vertical height estimate, the wavelength, and the GNSS satellite elevation angle, calculate the integer ambiguity; Based on the integer ambiguity, the wavelength, and the interference phase, the carrier phase path delay of the target antenna is calculated; The vertical altitude of the target antenna is calculated based on the carrier phase path delay and the GNSS satellite elevation angle. Based on the vertical height and the absolute height of the antenna, the absolute height of the target water surface is calculated.

[0062] For example, the estimated vertical height of the antenna can be calculated using spectral analysis, as shown in the following formula: (18) in, This represents the estimated vertical height of the antenna, and the estimated height of the antenna above the target water surface during the current time period. The wavelength representing the signal-to-noise ratio sequence; This represents the oscillation frequency of the signal-to-noise ratio sequence.

[0063] Furthermore, the integer ambiguity can be fixed according to the following formula: (19) in, Indicates integer ambiguity; Represents pi; This represents the estimated vertical height of the antenna; express GNSS satellite elevation angle at a given time; The wavelength representing the signal-to-noise ratio sequence; This represents the sine function.

[0064] Furthermore, the formula for calculating the carrier phase path delay of the antenna is as follows: (20) in, Indicates antenna The carrier phase path delay at a given moment is the carrier phase path delay between the direct signal and the reflected signal from the antenna. The wavelength representing the signal-to-noise ratio sequence; This represents the phase unwrapping function, used to convert discontinuous phases into continuous phases; express Interference phase at time; Indicates integer ambiguity; It represents pi (π).

[0065] Furthermore, the formula for calculating the vertical height of the antenna is as follows: (twenty one) in, Indicates the vertical height of the antenna; Indicates antenna The carrier phase path delay at any given moment; express GNSS satellite elevation angle at a given time; This represents the sine function.

[0066] It is understandable that when the target antenna is the first antenna, the carrier phase path delay of the first antenna can be calculated by substituting the first interference phase into equation (20), and then the vertical height of the first antenna can be calculated by substituting the carrier phase path delay of the first antenna into equation (21); the reverse is also true.

[0067] As one optional implementation, when the absolute height of the antenna is the absolute height of the target antenna, calculating the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: Subtract the vertical height from the absolute height of the antenna to obtain the absolute height of the target water surface.

[0068] It is understandable that while calculating the vertical height of the target antenna, the absolute height of the target antenna can also be obtained. Then, the absolute height of the target antenna minus the vertical height of the target antenna is the absolute height of the target water surface, which is also the water level.

[0069] As one optional implementation, when the absolute height of the antenna is the same as the absolute height of another antenna, calculating the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: The absolute height of the target water surface is obtained by subtracting the vertical height from the absolute height of the antenna and adding or subtracting the antenna spacing.

[0070] It is understandable that while calculating the vertical height of the target antenna, the absolute height of the other antenna can also be obtained. Therefore, when calculating the absolute height of the target water surface, the antenna spacing needs to be added or subtracted.

[0071] For example, when the target antenna is the first antenna (and the other antenna is the second antenna), combined with Figure 2 It can be seen that the absolute height of the target water surface satisfies the following relationship: (twenty two) in, Indicates the absolute height of the target water surface; Indicates the absolute height of the second skyline; Indicates the antenna spacing; Indicates the first antenna Vertical height at any given moment.

[0072] For example, when the target antenna is the second antenna (and the other antenna is a first antenna), then, combined with Figure 2 It can be seen that the absolute height of the target water surface satisfies the following relationship: (twenty three) in, Indicates the absolute height of the target water surface; Indicates the absolute height of the first tier; Indicates the antenna spacing; Indicates the second line Vertical height at any given moment.

[0073] Compared with existing technologies, the dual-antenna GNSS-IR water level monitoring method provided in this invention places the first antenna below the second antenna and uses a dual-antenna receiver to receive the signal-to-noise ratio (SNR) sequences of the first and second antennas respectively. Based on the antenna spacing, the antenna interference phase difference is calculated; based on the antenna interference phase difference, the interference phase of the target antenna is calculated; and based on the oscillation frequency and wavelength of the SNR sequence, the interference phase, the GNSS satellite elevation angle, and the absolute antenna altitude, the absolute altitude of the target water surface is calculated. Compared with existing technologies, this invention can solve the problem of low sampling rate in traditional single-antenna GNSS-IR altimeter measurement. Furthermore, compared with dual-antenna GNSS-IR, the signal tracking of this invention is more stable, and the hardware cost is lower.

[0074] See Figure 3 This invention also provides a dual-antenna GNSS-IR water level monitoring device 10, comprising: Signal input module 11 is used to set the first antenna below the second antenna and use a dual-antenna receiver to receive the signal-to-noise ratio sequences of the first antenna and the second antenna respectively; Interference phase difference calculation module 12 is used to calculate the antenna interference phase difference based on the antenna spacing; The interference phase calculation module 13 is used to calculate the interference phase of the target antenna based on the interference phase difference of the antenna. The water level calculation module 14 is used to calculate the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle and the absolute height of the antenna.

[0075] The dual-antenna GNSS-IR water level monitoring device provided in this embodiment of the invention can realize all the process steps of the dual-antenna GNSS-IR water level monitoring method described in the above embodiments. The functions and technical effects of each module and unit in the device are the same as the functions and technical effects of the dual-antenna GNSS-IR water level monitoring method described in the above embodiments. The specific implementation method will not be described in detail here.

[0076] See Figure 4 This invention also provides a dual-antenna GNSS-IR water level monitoring device 20, including a processor 21, a memory 22, and a computer program stored in the memory 22 and configured to be executed by the processor 21. When the processor 21 executes the computer program, it implements the steps described in the dual-antenna GNSS-IR water level monitoring method embodiments above, for example... Figure 1 The steps S1 to S4 described above; or, when the processor 21 executes the computer program, it implements the functions of each module in the above-described device embodiments.

[0077] The dual-antenna GNSS-IR water level monitoring device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The dual-antenna GNSS-IR water level monitoring device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the schematic diagram is merely an example of a dual-antenna GNSS-IR water level monitoring device and does not constitute a limitation on the device. It may include more or fewer components than illustrated, or combine certain components, or use different components. For example, the dual-antenna GNSS-IR water level monitoring device may also include input / output devices, network access devices, buses, etc.

[0078] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the dual-antenna GNSS-IR water level monitoring equipment, connecting all parts of the equipment via various interfaces and lines.

[0079] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the dual-antenna GNSS-IR water level monitoring device by running or executing the computer programs and / or modules stored in the memory, and by calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created according to the use of the controller, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0080] The integrated module of the dual-antenna GNSS-IR water level monitoring device, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0081] Compared with existing technologies, the dual-antenna GNSS-IR water level monitoring device, equipment, and storage medium provided in this invention places the first antenna below the second antenna and uses a dual-antenna receiver to receive the signal-to-noise ratio (SNR) sequences of the first and second antennas respectively; calculates the antenna interference phase difference based on the antenna spacing; calculates the interference phase of the target antenna based on the antenna interference phase difference; and calculates the absolute height of the target water surface based on the oscillation frequency and wavelength of the SNR sequence, the interference phase, the GNSS satellite elevation angle, and the absolute antenna height. Compared with existing technologies, this invention can solve the problem of low sampling rate in traditional single-antenna GNSS-IR altimeter measurement, and compared with dual-antenna GNSS-IR, the signal tracking of this invention is more stable and the hardware cost is lower.

[0082] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A dual-antenna GNSS-IR water level monitoring method, characterized in that, include: The first antenna is positioned below the second antenna, and a dual-antenna receiver is used to receive the signal-to-noise ratio sequences of the first antenna and the second antenna, respectively. Calculate the antenna interference phase difference based on the antenna spacing; Based on the antenna interference phase difference, the interference phase of the target antenna is calculated; The absolute height of the target water surface is calculated based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the absolute antenna height.

2. The dual-antenna GNSS-IR water level monitoring method as described in claim 1, characterized in that, The antenna interference phase difference is calculated using the following formula: in, Indicates the phase difference of antenna interference; express GNSS satellite elevation angle at a given time; Indicates the antenna spacing; The wavelength representing the signal-to-noise ratio sequence; Represents pi; This represents the sine function.

3. The dual-antenna GNSS-IR water level monitoring method as described in claim 1, characterized in that, If the target antenna is the first antenna, then the interference phase of the target antenna is calculated using the following formula: in, Indicates the interference phase of the first ray; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

4. The dual-antenna GNSS-IR water level monitoring method as described in claim 1, characterized in that, If the target antenna is a second antenna, then the interference phase of the target antenna is calculated using the following formula: in, Indicates the interference phase of the second antenna; This represents the detrended signal-to-noise ratio sequence of the first day's line; Indicates the phase difference of antenna interference; This represents the detrended signal-to-noise ratio sequence of the second day's chart; Represents the sine function; Represents the cosine function; This represents the arctangent function.

5. The dual-antenna GNSS-IR water level monitoring method as described in claim 1, characterized in that, The calculation of the absolute altitude of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interferometric phase, the GNSS satellite elevation angle, and the absolute antenna altitude includes: Based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, calculate the estimated vertical height of the antenna; Based on the antenna vertical height estimate, the wavelength, and the GNSS satellite elevation angle, calculate the integer ambiguity; Based on the integer ambiguity, the wavelength, and the interference phase, the carrier phase path delay of the target antenna is calculated; The vertical altitude of the target antenna is calculated based on the carrier phase path delay and the GNSS satellite elevation angle. Based on the vertical height and the absolute height of the antenna, the absolute height of the target water surface is calculated.

6. The dual-antenna GNSS-IR water level monitoring method as described in claim 5, characterized in that, When the absolute height of the antenna is the absolute height of the target antenna, calculating the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: Subtract the vertical height from the absolute height of the antenna to obtain the absolute height of the target water surface.

7. The dual-antenna GNSS-IR water level monitoring method as described in claim 5, characterized in that, When the absolute height of the antenna is the same as the absolute height of another antenna, calculating the absolute height of the target water surface based on the vertical height and the absolute height of the antenna includes: The absolute height of the target water surface is obtained by subtracting the vertical height from the absolute height of the antenna and adding or subtracting the antenna spacing.

8. A dual-antenna GNSS-IR water level monitoring device, characterized in that, include: The signal input module is used to set the first antenna below the second antenna and to use a dual-antenna receiver to receive the signal-to-noise ratio sequences of the first antenna and the second antenna, respectively. The interference phase difference calculation module is used to calculate the antenna interference phase difference based on the antenna spacing. The interference phase calculation module is used to calculate the interference phase of the target antenna based on the interference phase difference of the antenna. The water level calculation module is used to calculate the absolute height of the target water surface based on the oscillation frequency and wavelength of the signal-to-noise ratio sequence, the interference phase, the GNSS satellite elevation angle, and the absolute height of the antenna.

9. A dual-antenna GNSS-IR water level monitoring device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the dual-antenna GNSS-IR water level monitoring method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform the dual-antenna GNSS-IR water level monitoring method as described in any one of claims 1 to 7.

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