A sea surface wind speed inversion method based on satellite reflection signals and chip module

Abstract

A method for inverting sea surface wind speed based on satellite reflection signals, comprising: receiving positioning position information sent by a satellite navigation chip module; receiving a first direct signal and a reflected signal reflected by the sea surface from the satellite navigation chip module, and obtaining a correlation sequence of the first direct signal and the reflected signal based on the first direct signal and the reflected signal; obtaining the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal based on the correlation sequence; obtaining the wind speed value based on the correlation time, delay waveform area, and wind speed inversion model; and obtaining the sea surface wind speed in the target area based on the positioning position information and the wind speed value. This application extracts the characteristic observation quantity sea surface wind speed from multiple GEO reflection signals, uses shore-based GEO satellites to provide a stable geometric configuration, reduces signal processing complexity, and improves the accuracy of wind speed measurement. At the same time, the shore-based remote sensing platform has a fixed observation area and can perform long-term stable observations, with the advantages of a wide signal source, low cost, and light detection equipment.

Description

Technical Field

[0001] The present invention relates to the field of sea surface wind speed measurement, and in particular to a sea surface wind speed inversion method based on satellite reflection signals and a chip module. Background Art

[0002] Sea surface wind speed, as a physical parameter reflecting the state of the ocean surface, is a key factor influencing seawater movement and climate change. Coastal waters are closely connected to human activities, with numerous maritime transportation, fishing, aquaculture, and other activities taking place. Effective monitoring of wind speed in coastal waters is of great practical significance for their economic development and safe maritime operations. Commonly used methods for measuring sea surface wind speed include on-site and remote sensing. In-site monitoring primarily involves buoys and oceanographic stations, but their high construction costs make large-scale deployment in coastal waters unsuitable. Satellite remote sensing technologies such as altimeters, scatterometers, and radiometers can provide global-scale wind speed data, but due to limitations in temporal and spatial resolution, they cannot effectively monitor wind speed in coastal waters in real time. Airborne remote sensing technologies offer high flexibility but suffer from limited sustainability, preventing them from providing long-term continuous observations. Summary of the Invention

[0003] The main purpose of this application is to provide a method for inverting sea surface wind speed based on satellite reflection signals to at least partially solve the above problems. The sea surface wind speed inversion method includes:

[0004] Receive positioning information sent by the satellite navigation chip module;

[0005] receiving a first direct signal and a reflected signal reflected by the sea surface from a satellite navigation chip module, and obtaining a correlation sequence of the first direct signal and the reflected signal according to the first direct signal and the reflected signal;

[0006] Obtain the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal according to the correlation sequence;

[0007] Obtain wind speed values ​​based on correlation time, time-delay waveform area, and wind speed inversion model;

[0008] Obtain the sea surface wind speed in the target area based on the positioning position information and wind speed value.

[0009] Optionally, the satellite navigation chip module is a Beidou satellite navigation chip module composed of multiple Beidou geosynchronous orbit satellites.

[0010] Optionally, receiving the positioning position information sent by the satellite navigation chip module includes:

[0011] BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas receive the second direct signal sent by the BeiDou satellite navigation chip module;

[0012] The BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas send a second direct signal to the dual-frequency navigation chip-on-chip module;

[0013] The dual-frequency navigation chip module obtains positioning information based on the second direct signal;

[0014] The dual-frequency navigation chip module sends the positioning position information to the sea surface wind speed inversion module and the sea surface wind speed monitoring module.

[0015] Optionally, receiving a first direct signal and a reflected signal reflected by the sea surface from a satellite navigation chip module, and obtaining a correlation sequence of the first direct signal and the reflected signal according to the first direct signal and the reflected signal includes:

[0016] Two channels of the four-channel RF front end receive direct signals from the Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas, while the other two channels receive reflected signals from the Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas. The two channels then convert the direct and reflected signals into four digital intermediate frequency signals.

[0017] The four-channel RF front end sends four digital intermediate frequency signals to the direct / reverse signal collaborative processing module;

[0018] The direct / reflected signal collaborative processing module processes the direct signal and the reflected signal according to the four-channel digital intermediate frequency signal, and obtains the correlation sequence of the direct and reflected signals of multiple Beidou geosynchronous orbit satellites.

[0019] Optionally, obtaining the sea surface wind speed-sensitive correlation time and the delay waveform area of ​​the reflected signal according to the correlation sequence includes:

[0020] Generate digital carrier ref according to the preset fixed intermediate frequency value of the receiver carrieri (t) is multiplied by the direct signal and the reflected signal, and the carrier of the direct signal and the reflected signal is stripped. carrieri (t) is the local carrier of the i-th channel generated by the reference signal generation module in the direct / inverse signal collaborative processing module;

[0021] Performing a fast Fourier transform on the direct signal and the reflected signal after carrier stripping to obtain a first frequency domain form of the direct signal and the reflected signal;

[0022] Performing a fast Fourier transform on the local code to obtain a second frequency domain form of the local code, and performing conjugation on the second frequency domain form using a conjugate operator;

[0023] The first frequency domain form is multiplied by the conjugate of the second frequency domain form, and the multi-delay complex correlation value of the direct signal and the reflected signal is obtained according to the inverse Fourier transform and

[0024] The coherent integration time of the direct / reflected signal frequency domain parallel correlator of the direct / reflected signal collaborative processing module is set to the BeiDou B1I and B3I signal pseudo code period of 1ms, and the multi-delay complex correlation values ​​of the direct and reflected signals of multiple BeiDou geosynchronous orbit satellites are output. and To the sea surface wind speed retrieval module.

[0025] Optionally, obtaining the wind speed value according to the correlation time, the time-delay waveform area, and the wind speed inversion model includes:

[0026] Read the data of channel i, including the multi-delay complex correlation values ​​of the direct signal and the reflected signal and and the azimuth and altitude angles corresponding to the geosynchronous orbit satellite;

[0027] When the corresponding geosynchronous orbit satellite azimuth Ai satisfies A min <A i <A max When the signal is detected by the antenna, it is considered that the satellite signal is within the observation range of the antenna and subsequent processing is performed;

[0028] The delay waveform of the reflected signal is obtained by non-coherently accumulating the complex correlation values ​​of the multiple delays of the reflected signal, that is:

[0029] Among them, Y cohim (τ) is N coh The complex time delay waveform of the sub-coherent accumulation is

[0030] The signal-to-noise ratio of the delayed waveform of the reflected signal is solved according to the peak signal-to-noise ratio, that is:

[0031]

[0032] Among them, P peak and P noise are the peak power and noise power of the reflected signal delay:

[0033] P peak =max{<|Y i (τ)| 2 >},

[0034] Among them, max{·} is the maximum operator; E{·} is the mean operator; Indicates that the delay is less than T τ The time delay waveform of

[0035] When the signal-to-noise ratio is greater than the preset threshold, the subsequent wind speed inversion step is entered;

[0036] The waveform area is calculated using the normalized reflected signal delay waveform, namely:

[0037]

[0038] Among them, T h is a given threshold; <|Y Ni (τ)| 2 > is the normalized reflected signal delay waveform:

[0039]

[0040] Invert wind speed based on waveform area:

[0041] Among them, a A and b A are the inversion model parameters;

[0042] Calculate the interference complex field based on the direct and reflected complex delay correlation values:

[0043] in, is the complex correlation value at the peak of the time delay waveform of the reflected signal and the direct signal;

[0044] The correlation function is obtained based on the interference complex field:

[0045] Where M is the number of interference complex field samples, For S icf The conjugate of (j) is used to calculate the correlation time:

[0046] Calculate the sea surface wind speed based on the relevant time:

[0047] Among them, a icf and b icf are the inversion model parameters;

[0048] The sea surface wind speed independently inverted by each channel is fused according to the linear unbiased minimum variance estimator: 10 =m·U 10

[0049] Among them, U 10 The wind speed vector composed of the independent inversion wind speed of each channel is:

[0050] U 10 =[U A1 ,U icf1 ,…,U AN ,U icfN ]

[0051] m is the weight vector of the linear combination. Under the constraint ||m||=1, the minimum variance criterion is used to make Minimum obtainable:

[0052] Among them, C WS is the covariance matrix of wind speed inversion for each independent characteristic parameter, and the element in row i and column j is expressed as: C WSij =<(u i -u true )·(u j -u true ) T >

[0053] Among them, u i and u j Indicates the wind speed independently inverted by each channel, u true is the true wind speed at the same position.

[0054] According to another aspect of the present application, a chip module for inverting sea surface wind speed based on satellite reflected signals is also provided, comprising:

[0055] A Beidou dual-frequency navigation chip-on-chip module is configured to receive positioning position information sent by a satellite navigation chip module;

[0056] a direct / reflected collaborative processing module configured to receive a direct signal from the satellite navigation chip module and a reflected signal reflected by the sea surface, and obtain a correlation sequence of the direct signal and the reflected signal based on the direct signal and the reflected signal;

[0057] A sea surface wind speed inversion module is configured to receive a correlation sequence, obtain the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal according to the correlation sequence, and obtain the wind speed value according to the correlation time and delay waveform area;

[0058] The sea surface wind speed monitoring module is configured to obtain the sea surface wind speed in the target area based on the positioning position information and the wind speed value.

[0059] Optionally, the sea surface wind speed inversion chip module further includes:

[0060] BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas are set to face south and receive direct signals from BeiDou geosynchronous orbit satellite navigation chip modules.

[0061] Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas are set up facing the sea surface to the south, and receive the reflected signals of the Beidou geosynchronous orbit satellite navigation chip module reflected by the sea surface.

[0062] Optionally, the sea surface wind speed inversion chip module further includes:

[0063] The four-channel RF front end receives direct signals sent by the Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas and reflected signals sent by the Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas.

[0064] Optionally, the direct / reflected collaborative processing module includes: a reference signal generation module and a direct / reflected signal frequency domain parallel correlator;

[0065] A reference signal generation module and a direct / inverse signal frequency domain parallel correlator constitute a signal processing channel.

[0066] Compared with the prior art, this application has the following beneficial effects:

[0067] Along my country's coastline, when the sea-facing antenna is erected facing south, multiple GEO (GEostationary Orbit) satellite signals are stable within the field of view of the same reflector antenna, and multiple characteristic parameters within the same time-delay waveform are sensitive to wind speed, creating the necessary conditions for optimal inversion using multi-satellite, multi-frequency, and multi-parameter fusion. By extracting the characteristic observational sea surface wind speed from the combined reflected signals of multiple Beidou GEO satellites, the stable geometric configuration provided by GEO satellites in shore-based scenarios is fully utilized, reducing signal processing complexity and improving wind speed measurement accuracy. Furthermore, shore-based remote sensing platforms offer fixed observation areas, long-term stable observation capabilities, and the advantages of a wide signal source, low cost, and lightweight detection equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The drawings that constitute part of this application are used to provide a further understanding of this application and make other features, objectives and beneficial effects of this application more apparent. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0069] Figure 1 This is a flow chart of a method for inverting sea surface wind speed based on satellite reflected signals according to one embodiment of the present application;

[0070] Figure 2 is a flow chart of a method for inverting sea surface wind speed based on satellite reflected signals according to another embodiment of the present application;

[0071] Figure 3 is a flow chart of a method for inverting sea surface wind speed based on satellite reflected signals according to another embodiment of the present application;

[0072] Figure 4 This is the overall architecture of a shore-based BeiDou GEO reflected signal sea surface wind speed inversion chip module according to one embodiment of the present application;

[0073] Figure 5is a block diagram of a multi-channel direct / reverse collaborative processing module according to one embodiment of the present application;

[0074] Figure 6 is a frequency domain parallel correlator according to one embodiment of the present application;

[0075] Figure 7 This is a sea surface wind speed inversion process according to an embodiment of the present application. DETAILED DESCRIPTION

[0076] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0077] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to facilitate the embodiments of the present application described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, chip module, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0078] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0079] Please refer to Figure 1-Figure 7 An embodiment of the present application provides a method for inverting sea surface wind speed based on satellite reflection signals, comprising:

[0080] S1: Receive positioning information sent by the satellite navigation chip module;

[0081] The BeiDou B1I and B3I dual-mode navigation SoCs (System on Chip) receive direct signals from the BeiDou satellite navigation chip module sent by the satellite antenna. The direct signals include positioning information, and send out the received positioning information.

[0082] S3: receiving a first direct signal from a satellite navigation chip module and a reflected signal reflected by the sea surface, and obtaining a correlation sequence of the first direct signal and the reflected signal according to the first direct signal and the reflected signal;

[0083] The direct / reflected signal collaborative processing module receives the first direct signal from the satellite navigation chip module and the reflected signal reflected by the sea surface, and performs correlation processing on the first direct signal and the reflected signal to obtain the complex correlation sequence of the direct and reflected signals of N Beidou GEO satellites.

[0084] S5: Obtain the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal based on the correlation sequence;

[0085] The sea surface wind speed inversion module receives the complex correlation sequences of direct and reflected signals from N BeiDou GEO satellites, and extracts the correlation time and delay waveform area of ​​the reflected signal that are sensitive to sea surface wind speed.

[0086] S7: Obtain wind speed value according to correlation time, time-delay waveform area and wind speed inversion model;

[0087] The sea surface wind speed inversion module uses the wind speed inversion model to invert the sea surface wind speed.

[0088] S9: Obtain the sea surface wind speed in the target area according to the positioning position information and the wind speed value.

[0089] The sea surface wind speed monitoring module receives the wind speed information output by the sea surface wind speed inversion module and displays the positioning position information output by the Beidou B1I and B3I dual-frequency navigation SOC.

[0090] In this embodiment, the satellite navigation chip module is a Beidou satellite navigation chip module composed of multiple Beidou geosynchronous orbit satellites, but it is not limited to this. Those skilled in the art can use any known satellite navigation chip module according to actual conditions, which are all within the scope of protection required by this application.

[0091] In other embodiments of the present application, receiving positioning information sent by the satellite navigation chip module includes:

[0092] S11: Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas receive the second direct signal sent by the Beidou satellite navigation chip module;

[0093] S12: The BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas send a second direct signal to the dual-frequency navigation chip module;

[0094] S13: The dual-frequency navigation chip module obtains positioning position information according to the second direct signal;

[0095] S14: The dual-frequency navigation chip module sends the positioning position information to the sea surface wind speed inversion module and the sea surface wind speed monitoring module.

[0096] The BeiDou B1I and B3I dual-frequency RHCP antennas are positioned facing south to receive direct signals from the BeiDou GEO satellite navigation chip module. The BeiDou B1I and B3I dual-frequency LCHP antennas are positioned southward to face the sea and receive reflected signals from the BeiDou satellite navigation chip module. The BeiDou B1I and B3I dual-mode navigation SoC input terminals are connected to the BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas, receiving the direct signals from the BeiDou satellite navigation chip module to complete navigation positioning. The output terminals are interconnected with the sea surface wind speed inversion and monitoring module, outputting the received positioning information to the sea surface wind speed inversion module and the sea surface wind monitoring module. The remaining steps are the same as those in the above embodiment and will not be repeated here.

[0097] In this embodiment, the BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas are used to receive the BeiDou B1I and B3I direct electromagnetic signals and convert the electromagnetic signals into radio frequency voltage signals S d (t). The BeiDou B1I and B3I dual-frequency left-hand circularly polarized antennas are used to receive the BeiDou B1I and B3I electromagnetic signals reflected from the sea surface and convert them into radio frequency voltage signals S r The BeiDou B1I and B3I dual-frequency navigation SoC is a mature navigation SoC module that receives signals from the BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas for navigation and positioning, and outputs azimuth, elevation, and positioning information.

[0098] In other embodiments of the present application, receiving a first direct signal and a reflected signal reflected by the sea surface from a satellite navigation chip module, and obtaining a correlation sequence of the first direct signal and the reflected signal according to the first direct signal and the reflected signal includes:

[0099] S31: Two channels of the four-channel RF front end receive direct signals from the Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas, and the other two channels receive reflected signals from the Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas. The system then converts the direct and reflected signals into four digital intermediate frequency signals.

[0100] S32: The four-channel RF front end sends four digital intermediate frequency signals to the direct / reverse signal collaborative processing module;

[0101] S33: The direct / reflected signal collaborative processing module processes the direct signal and the reflected signal according to the four-channel digital intermediate frequency signal, and obtains the correlation sequence of the direct and reflected signals of multiple Beidou geosynchronous orbit satellites.

[0102] Two channels of the four-channel RF front end are connected to the Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas, and the other two channels are connected to the Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas. Four digital intermediate frequency signals are output to the direct / reflected signal collaborative processing module to complete the correlation processing of the direct and reflected signals. The direct / reflected signal collaborative processing module is interconnected with the four-channel RF front end and correlates the direct / reflected signals output by the four-channel RF front end to obtain the complex correlation sequence of the direct and reflected signals of N Beidou GEO satellites. The other steps are the same as those in the above embodiment and are not repeated here.

[0103] In this embodiment, the four-channel RF front end includes the BeiDou B1I signal RF front end and the BeiDou B3I signal RF front end. The two sub-RF front ends are composed of two RF channels with exactly the same structure, which respectively perform frequency conversion, filtering, gain control, and sampling quantization on the BeiDou B1I direct and reflected signals. The RF front end module receives the RF signal S output by the right-hand circularly polarized antenna and the left-hand circularly polarized antenna. d (t) and S r (t), output four digital IF signals, corresponding to the BeiDou B1I direct digital IF signal, B1I reflected digital IF signal, BeiDou B3I direct digital IF signal, and BeiDou B3I reflected digital IF signal. The BeiDou B1I and B3I signal processing is exactly the same. For the sake of convenience, the IF signals are not distinguished between BeiDou B1I and B3I. It is assumed that the direct IF signal is S d (n), the reflected intermediate frequency signal is S r (n).

[0104] The multi-channel direct / reflected signal collaborative processing module consists of N reference signal generation modules and N direct / reflected signal frequency domain parallel correlators. One reference signal generation module and one direct / reflected signal frequency domain parallel correlator constitute a signal processing channel. Since the B1I and B3I signal processing are consistent with the generated local carrier and the corresponding RF front-end intermediate frequency, the local code and the corresponding PRN number are consistent, and the processing process is exactly the same, the B1I and B3I signals are not distinguished in the subsequent discussion, and the processing channels are uniformly numbered 1 to N. Since the Pseudo-Random Noise (PRN) of Beidou GEO is numbered 1 to 5 and 59 to 61. The processing channel of Beidou B1I signal is 1 to N / 2, and the processing channel of Beidou B3I signal is N / 2+1 to N;

[0105] The reference signal generation module generates a local carrier and a local pseudo code sequence. In the present invention, the local carrier and local pseudo code of the BeiDou GEO satellite are generated. The frequency of the local carrier is consistent with the center frequency of the RF front end. The local code generates B1I and B3I pseudo random codes with PRN numbers 1 to 5 and 59 to 61. Assume that the local carrier of the i-th channel is denoted as ref carrieri(t), the local code is denoted as ref codei (t).

[0106] In other embodiments of the present application, the direct / reflected signal frequency domain parallel correlator is composed of a multiplier, a fast Fourier transform, an inverse fast Fourier transform, and a conjugate operator, and primarily performs multi-delay correlation processing of the B1I and B3I direct, reflected, and local signals. Therefore, obtaining the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal based on the correlation sequence includes the following steps:

[0107] 1) Generate digital carrier ref according to the fixed intermediate frequency value of the preset receiver carrieri (t) is multiplied by the direct signal and the reflected signal, and the carrier of the direct signal and the reflected signal is stripped. carrieri (t) is the local carrier of the i-th channel generated by the reference signal generation module in the direct / inverse signal collaborative processing module;

[0108] 2) performing a fast Fourier transform on the direct signal and the reflected signal after carrier stripping to obtain a first frequency domain form of the direct signal and the reflected signal;

[0109] 3) performing a fast Fourier transform on the local code to obtain a second frequency domain form of the local code, and performing conjugation on the second frequency domain form using a conjugate operator;

[0110] 4) Multiply the conjugate of the first frequency domain form and the second frequency domain form, and obtain the multi-delay complex correlation value of the direct signal and the reflected signal according to the inverse Fourier transform and

[0111] 5) The coherent integration time of the direct / reflected signal frequency domain parallel correlator of the direct / reflected signal collaborative processing module is set to the BeiDou B1I and B3I signal pseudo code period of 1ms, and the multi-delay complex correlation values ​​of the direct and reflected signals of multiple BeiDou geosynchronous orbit satellites are output. and To the sea surface wind speed retrieval module.

[0112] In other embodiments of the present application, obtaining the wind speed value according to the correlation time, the time-delay waveform area, and the wind speed inversion model includes:

[0113] 1) Read the data of channel i, including the multi-delay complex correlation values ​​of the direct signal and the reflected signal and and the azimuth and altitude angles corresponding to the geosynchronous orbit satellite;

[0114] 2) When the corresponding geosynchronous orbit satellite azimuth Ai satisfies A min <A i <A maxWhen the signal is detected by the antenna, it is considered that the satellite signal is within the observation range of the antenna and subsequent processing is performed;

[0115] 3) The delayed waveform of the reflected signal is obtained by non-coherently accumulating the complex correlation values ​​of the multiple delays of the reflected signal, that is:

[0116] Among them, Y cohim (τ) is N coh The complex time delay waveform of the sub-coherent accumulation is

[0117] 4) Calculate the signal-to-noise ratio of the delayed waveform of the reflected signal based on the peak signal-to-noise ratio, that is:

[0118]

[0119] Among them, P peak and P noise are the peak power and noise power of the reflected signal delay:

[0120] P peak =max{<|Y i (τ)| 2 >},

[0121] Among them, max{·} is the maximum operator; E{·} is the mean operator; Indicates that the delay is less than T τ The time delay waveform of

[0122] 5) When the signal-to-noise ratio is greater than the preset threshold, the subsequent wind speed inversion step is entered;

[0123] 6) Calculate the waveform area using the normalized reflected signal delay waveform, that is:

[0124]

[0125] Among them, T h is a given threshold; <|Y Ni (τ)| 2 > is the normalized reflected signal delay waveform:

[0126]

[0127] 7) Invert wind speed based on waveform area:

[0128] Among them, a A and b A are the inversion model parameters;

[0129] 8) Calculate the interference complex field based on the direct and reflected complex delay correlation values:

[0130] in, is the complex correlation value at the peak of the time delay waveform of the reflected signal and the direct signal;

[0131] 9) Obtain the correlation function based on the interference complex field:

[0132] Where M is the number of interference complex field samples, For S icf The conjugate of (j) is used to calculate the correlation time:

[0133] 10) Calculate sea surface wind speed based on relevant time:

[0134] Among them, a icf and b icf are the inversion model parameters;

[0135] 11) According to the linear unbiased minimum variance estimator, the sea surface wind speed independently inverted by each channel is fused: u 10 =m·U 10

[0136] Among them, U 10 The wind speed vector composed of the independent inversion wind speed of each channel is:

[0137] U 10 =[U A1 ,U icf1 ,…,U AN ,U icfN ]

[0138] m is the weight vector of the linear combination. Under the constraint ||m||=1, the minimum variance criterion is used to make Minimum obtainable:

[0139] Among them, C WS is the covariance matrix of wind speed inversion for each independent characteristic parameter, and the element in row i and column j is expressed as: C WSij =<(u i -u true )·(u j -u true ) T >

[0140] Among them, u i and u j Indicates the wind speed independently inverted by each channel, u true is the true wind speed at the same position.

[0141] In this embodiment, when the next step is carried out conditionally, it may also include a judgment step of whether the conditions on that day meet the preset conditions, which are all within the scope of protection required by this application.

[0142] The present invention provides a method and chip module for inverting sea surface wind speed from Beidou GEO reflected signals. The chip module can receive and process GEO B1I and B3I reflected signals from N satellites in the same area to invert sea surface wind speed. First, a multi-channel direct reflection collaborative processing module is used to obtain a complex correlation value sequence of the B1I and B3I reflected signals from N Beidou GEO satellites. Then, a micro host computer extracts the correlation time and time delay waveform area characteristic observations of the B1I and B3I reflected signals from the N GEO satellites, and inverts the sea surface wind speed.

[0143] The present application also provides a sea surface wind speed inversion chip module based on satellite reflection signals, including: Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas, Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas, four-channel RF front-end, Beidou B1I and B3I dual-frequency navigation SoC (System on Chip, chip-on-chip module); multi-channel direct / reflected signal collaborative processing module, sea surface wind speed inversion module, and sea surface wind speed monitoring module. Among them, the Beidou B1I and B3I dual-frequency navigation on-chip chip modules are configured to receive the positioning position information sent by the satellite navigation chip module; the direct / reflected collaborative processing module is configured to receive the direct signal of the satellite navigation chip module and the reflected signal reflected by the sea surface, and obtain the correlation sequence of the direct signal and the reflected signal based on the direct signal and the reflected signal; the sea surface wind speed inversion module is configured to receive the correlation sequence, obtain the sea surface wind speed-sensitive correlation time and delay waveform area of ​​the reflected signal according to the correlation sequence, and obtain the wind speed value based on the correlation time and delay waveform area; the sea surface wind speed monitoring module is configured to obtain the sea surface wind speed in the target area according to the positioning position information and the wind speed value. The BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas are positioned facing south and receive direct signals from the BeiDou geosynchronous orbit satellite navigation chip module. The BeiDou B1I and B3I dual-frequency left-hand circularly polarized antennas are positioned facing south toward the sea and receive reflected signals from the BeiDou geosynchronous orbit satellite navigation chip module. The four-channel RF front end receives direct signals from the B1I and B3I dual-frequency right-hand circularly polarized antennas and reflected signals from the left-hand circularly polarized antennas. The direct / reflected collaborative processing module includes a reference signal generation module and a direct / reflected signal frequency domain parallel correlator. A reference signal generation module and a direct / reflected signal frequency domain parallel correlator form a signal processing channel.

[0144] In other embodiments of the present application, the Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas receive the Beidou satellite navigation chip module B1I and B3I signals reflected by the sea surface, and convert the electromagnetic signals into voltage signals.

[0145] The four-channel RF front end down-converts, filters, gain controls, and samples and quantizes the direct and reflected RF signals of Beidou B1I and B3I transmitted by the right-hand circularly polarized and left-hand circularly polarized antennas into digital intermediate frequency signals.

[0146] The Beidou B1I and B3I dual-mode navigation SoC receives the signals output by the Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas for navigation and positioning, and outputs the positioning information to the sea surface wind speed inversion and monitoring module.

[0147] The multi-channel direct / reflected signal collaborative processing module consists of 4N direct / reflected signal frequency domain correlators, which performs frequency domain parallel correlation processing on the direct and reflected signals of N Beidou GEO satellites B1I and B3I to obtain complex correlation values.

[0148] The sea surface wind speed inversion module uses the multi-channel direct / reflected signal collaborative processing module to output the complex correlation values ​​of the B1I and B3I direct and reflected signals of N Beidou satellites, extracts the characteristic parameters sensitive to the sea surface wind speed, and inverts the sea surface wind speed.

[0149] The sea surface wind speed monitoring module receives the wind speed output by the sea surface wind speed inversion module and the positioning information output by the Beidou B1I and B3I dual-mode navigation SoC for visual display and monitoring.

[0150] The local pseudo-random code mentioned in this application refers to the pseudo-random code generated by the receiver end, which is the generated entity. It is essentially different from the pseudo-random code signal and cannot be confused. The pseudo-random code cannot be changed.

[0151] At the same time, in this application, the B1I signal and the B3I signal are both signals in the Beidou navigation chip module, where the nominal carrier frequency of the B1I signal is 1561.098 MHz. The B1I signal bandwidth is 4.092 MHz (centered on the B1I signal carrier frequency). The B1I signal is broadcast on the medium earth orbit (MEO) satellites, inclined geosynchronous orbit (IGSO) satellites and geostationary orbit (GEO) satellites of Beidou-2 and Beidou-3, providing public services. The B3I signal is broadcast on the medium earth orbit (MEO) satellites, inclined geosynchronous orbit (IGSO) satellites and geostationary orbit (GEO) satellites of Beidou-2 and Beidou-3, providing public services.

[0152] The chip module referred to in this application specifically refers to the "Lixia" shore-based Beidou Ocean Wind and Wave Chip Module. The "Lixia" shore-based Beidou Ocean Wind and Wave Chip Module integrates real-time processing of Beidou satellite navigation signals, real-time positioning of observation stations, real-time inversion of sea surface wind speed and significant wave height, and data transmission. This enables real-time observation of significant wave height and wind speed in nearshore waters at a single station without relying on external computing resources.

[0153] The "Lixia" shore-based Beidou sea breeze and wave chip module innovatively applies the Beidou-3 navigation system and the Beidou B1I signal reflected by the sea surface to realize the inversion of effective wave height and wind speed on the sea surface at a single nearshore station, with a time resolution of up to minutes; effective wave height and wind speed observations are integrated at the system level, which improves business capabilities while reducing the deployment cost of the observation network, and is especially suitable for deployment on remote islands or coasts with limited power supply.

[0154] The "Lixia" module develops sea breeze and wave detection technology based on Beidou navigation satellites, breaking the pain points of high cost and difficult deployment of traditional offshore wind and wave detection, and providing a new means of observing offshore sea breeze and waves. It can, to a certain extent, change the long-standing situation of lack of ocean data, lack of effective observation means, and insufficient observation capabilities in my country's comprehensive meteorological observation system, fill the gap in meteorological observation data, and is especially convenient for deployment on remote islands or coasts with difficult power supply. It can provide equipment and technical reserves for major projects such as marine engineering, and provide solid support for the upgrading and transformation of my country's marine meteorological observation technology and high-quality development.

[0155] The "Lixia" shore-based Beidou sea wind and wave detection chip module realizes the chip integration of real-time data quality control of the Beidou satellite navigation system's reflected signal and the real-time inversion algorithm of sea surface wind speed and effective wave height. It is an innovative technology for low-cost, low-power detection of near-coast sea surface wind speed and effective wave height.

[0156] In addition to its primary Beidou satellite functions, the "Lixia" module is also compatible with the GPS system, enabling dual-system collaborative detection. The module has undergone preliminary field testing. Test results demonstrate that the module's wind speed retrieval accuracy is 2 m / s (for wind speeds < 20 m / s), and its significant wave height retrieval accuracy is 20 cm (for significant wave heights < 2 m) and 10% (for significant wave heights ≥ 2 m). These indicators meet the requirements of operational meteorological applications.

[0157] Compared with the prior art, the advantages of this application are:

[0158] The chip module is only a signal receiving chip module, and the chip module has a simple structure, low cost and low power consumption;

[0159] The chip module uses GNSS (Global Navigation Satellites System) signals as the signal source and can implement all-weather observation;

[0160] The chip module fully utilizes BeiDou GEO satellites to provide a stable geometric configuration in shore-based scenarios, and utilizes multi-satellite, multi-frequency and multi-parameter fusion inversion algorithms to achieve high wind speed inversion accuracy.

[0161] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for inverting sea surface wind speed based on satellite reflected signals, characterized in that: include: Receive positioning information sent by a satellite navigation chip module, where the satellite navigation chip module is a Beidou satellite navigation chip module composed of multiple Beidou geosynchronous orbit satellites, including: The Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas receive the second direct signal sent by the Beidou satellite navigation chip module; The BeiDou B1I and B3I dual-frequency right-hand circularly polarized antennas transmit the second direct signal to the dual-frequency navigation chip-on-chip module; The dual-frequency navigation chip module obtains positioning position information according to the second direct signal; The dual-frequency navigation chip module sends the positioning position information to the sea surface wind speed inversion module and the sea surface wind speed monitoring module; Receiving a first direct signal and a reflected signal reflected by the sea surface from the satellite navigation chip module, and obtaining a correlation sequence of the first direct signal and the reflected signal according to the first direct signal and the reflected signal, comprising: Two channels of the four-channel RF front end receive the first direct signal sent by the Beidou B1I and B3I dual-frequency right-hand circularly polarized antenna, and the other two channels receive the reflected signal sent by the Beidou B1I and B3I dual-frequency left-hand circularly polarized antenna, and convert the first direct signal and the reflected signal into four digital intermediate frequency signals; The four-channel RF front end sends the four digital intermediate frequency signals to the direct / reflected signal collaborative processing module; The direct / reflected signal collaborative processing module processes the first direct signal and the reflected signal according to the four digital intermediate frequency signals, and obtains correlation sequences of the direct and reflected signals of multiple Beidou geosynchronous orbit satellites; Acquiring the sea surface wind speed-sensitive correlation time and the delayed waveform area of ​​the reflected signal according to the correlation sequence, including: Generate digital carrier ref according to the preset fixed intermediate frequency value of the receiver carrieri (t), the digital carrier ref carrieri (t) and the first direct signal and the reflected signal are multiplied respectively, and the first direct signal and the reflected signal are subjected to carrier stripping, ref carrieri (t) is the local carrier of the i-th channel generated by the reference signal generation module in the direct / reflected signal collaborative processing module; Performing a fast Fourier transform on the first direct signal and the reflected signal after carrier stripping to obtain first frequency domain forms of the first direct signal and the reflected signal; Performing a fast Fourier transform on the local code to obtain a second frequency domain form of the local code, and conjugating the second frequency domain form using a conjugate operator; The first frequency domain form is conjugate multiplied by the second frequency domain form, and a multi-delay complex correlation value of the first direct signal and the reflected signal is obtained according to the inverse Fourier transform. and The coherent integration time of the direct / reflected signal frequency domain parallel correlator of the direct / reflected signal collaborative processing module is set to 1ms of the Beidou B1I and B3I signal pseudo code period, and the multi-delay complex correlation values ​​of the first direct signal and the reflected signal of the multiple Beidou geosynchronous orbit satellites are output. and To the sea surface wind speed inversion module; Obtaining a wind speed value according to the correlation time, the time-delay waveform area, and a wind speed inversion model includes: Read the data of the i-th channel, including the multi-delay complex correlation value of the first direct signal and the reflected signal and and the azimuth and altitude angles corresponding to the geosynchronous orbit satellite; When the corresponding geosynchronous orbit satellite azimuth angle A i Satisfy A min <A i <A max When the signal from the satellite is within the observation range of the antenna, subsequent processing is performed; The delay waveform of the reflected signal is obtained by performing non-coherent accumulation of the multiple delay complex correlation values ​​of the reflected signal, that is: Among them, Y cohim (τ) is N coh The complex time delay waveform of the sub-coherent accumulation is ， N incoh The number of times the multi-delay complex correlation values ​​of the reflected signal are non-coherently accumulated; The signal-to-noise ratio of the delayed waveform of the reflected signal is solved according to the peak signal-to-noise ratio, that is: Among them, P peak and P noise are the peak power and noise power of the reflected signal delay: P peak =max{<|Y i (t)| 2 >}, Among them, max{·} is the maximum operator; E{·} is the mean operator; Indicates that the delay is less than T τ The time delay waveform of When the signal-to-noise ratio is greater than a preset threshold, the subsequent wind speed inversion step is entered; The waveform area is calculated using the normalized reflected signal delay waveform, namely: Among them, T h is a given threshold; <|Y Ni (τ)| 2 > is the normalized reflected signal delay waveform: Invert the wind speed based on the waveform area: Among them, a A and b A are the inversion model parameters; Calculate the interference complex field according to the multi-delay complex correlation value of the first direct signal and the reflected signal: in, is the multi-delay complex correlation value between the reflected signal and the first direct signal at the peak of the delay waveform; The correlation function is obtained according to the interference complex field: ； Where M is the number of interference complex field samples, For S icf The conjugate of (j) is used to calculate the correlation time: Calculate the sea surface wind speed based on the stated relative times: Among them, a icf and b icf are the inversion model parameters; The sea surface wind speed independently inverted by each channel is fused according to the linear unbiased minimum variance estimator: 10 =m·U 10 , where U 10 The wind speed vector formed by the independent inversion of wind speed in each channel is: IN 10 =[U A1 ,IN icf1 ,…,IN AN ,IN icfN ] N represents the number of independent inversion channels for wind speed, m is the weight vector of linear combination, and under the constraint ||m||=1, the minimum variance criterion is used to make Minimum obtainable: ； Among them, C WS is the covariance matrix of wind speed inversion for each independent characteristic parameter, and the element in row i and column j is expressed as: C WSij =<(u i -u true )·(u j -u true ) T > Among them, u i and u j Indicates the wind speed independently inverted by each channel, u true is the actual wind speed at the same location; and the sea surface wind speed in the target area is obtained according to the positioning position information and the wind speed value.

2. A sea surface wind speed inversion chip module based on satellite reflection signals, used to implement the sea surface wind speed inversion method according to claim 1, characterized in that: include: A Beidou dual-frequency navigation chip-on-chip module is configured to receive positioning position information sent by a satellite navigation chip module; a direct / reflected signal collaborative processing module, configured to receive a first direct signal from the satellite navigation chip module and a reflected signal reflected by the sea surface, and obtain a correlation sequence of the first direct signal and the reflected signal based on the first direct signal and the reflected signal; A sea surface wind speed inversion module is configured to receive the correlation sequence, obtain the sea surface wind speed-sensitive correlation time and the time-delay waveform area of ​​the reflected signal according to the correlation sequence, and obtain the wind speed value according to the correlation time and the time-delay waveform area; The sea surface wind speed monitoring module is configured to obtain the sea surface wind speed of the target area according to the positioning position information and the wind speed value.

3. The sea surface wind speed inversion chip module based on satellite reflected signals according to claim 2 is characterized in that: The sea surface wind speed inversion chip module also includes: Beidou B1I and B3I dual-frequency right-hand circularly polarized antennas, which are arranged to face south and receive the first direct signal from the Beidou geosynchronous orbit satellite navigation chip module; Beidou B1I and B3I dual-frequency left-hand circularly polarized antennas are arranged facing the sea surface and face south, and receive the reflected signal of the Beidou geosynchronous orbit satellite navigation chip module reflected by the sea surface.

4. The chip module for inverting sea surface wind speed based on satellite reflected signals according to claim 3, characterized in that: The sea surface wind speed inversion chip module also includes: A four-channel RF front end receives the first direct signal sent by the Beidou B1I and B3I dual-frequency right-hand circularly polarized antenna and the reflected signal sent by the Beidou B1I and B3I dual-frequency left-hand circularly polarized antenna.

5. The sea surface wind speed inversion chip module based on satellite reflected signals according to claim 4 is characterized in that: The direct / reflected signal collaborative processing module includes: a reference signal generation module and a direct / reflected signal frequency domain parallel correlator; One of the reference signal generation modules and one of the direct / reflected signal frequency domain parallel correlator constitutes a signal processing channel.

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