Multi-satellite coordinated GNSS-R sea surface vector wind field detection system and on-orbit inversion method

Abstract

The present invention relates to a multi-satellite coordinated GNSS-R sea surface vector wind field detection system and an on-orbit inversion method. The system comprises: a master GNSS-R satellite (100) for receiving, capturing, tracking, and detecting a navigation satellite reflected signal of a mirror reflection point within a detection area, processing a time delay Doppler map of a region corresponding to the reflected signal in real time, recording detection system status information, fusing observation information of a slave GNSS-R satellite (200), and inverting a vector wind field; N slave GNSS-R satellites (200) for receiving, capturing, tracking, and detecting a navigation satellite scattered signal of a mirror reflection point within a detection area, processing a time delay Doppler map of a region corresponding to the scattered signal in real time, and recording detection system status information; the master GNSS-R satellite (100) is located at a central position, and the N slave GNSS-R satellites (200) are evenly distributed and follow the master GNSS-R satellite (100); the master GNSS-R satellite (100) and the N slave GNSS-R satellites (200) exchange information and transmit detection data via inter-satellite links. The present invention effectively improves the inversion accuracy and reliability of sea surface wind speed and direction.

Description

Technical Field

[0001] The present invention relates to the technical field of sea surface wind field detection and inversion, and in particular to a multi-satellite coordinated GNSS-R sea surface vector wind field detection system and an on-orbit inversion method. Background Art

[0002] The sea surface wind field is a key element of the ocean and atmosphere, directly driving ocean circulation activities and playing an important role in regional and global climate change. Obtaining high-precision ocean wind fields is of great significance for marine disaster warning, precise monitoring of marine activities and marine climate research. Traditional means of monitoring ocean wind fields include offshore buoys, coastal meteorological stations, ships, etc., but the above-mentioned observation methods have low observation efficiency and small detection range. With the development of space technology, satellite remote sensing such as microwave scatterometers, radiometers and synthetic aperture radars are widely used in sea surface wind field measurements. However, there are disadvantages such as limited signal coverage and high detection costs. In the past three decades, with the development of the application of satellite-borne GNSS-R (Global Navigation Satellite System-Reflectometry) technology in ocean wind field inversion, it has not only overcome the shortcomings of traditional remote sensing measurements, but also has the advantages of all-weather "natural" L-band signal sources available, simultaneous observation along multiple reflection point trajectories, low cost, and low power consumption.

[0003] The UK-DMC and TDS-1 satellites launched by the UK, the CYGNSS constellation launched by the US, and the Fenghu-1A / B dual satellites launched by China have all verified the reliability of spaceborne GNSS-R sea surface wind measurements in orbit. Related research results show that the accuracy of spaceborne GNSS-R sea surface wind speed retrievals is 2 m / s at low sea surface speeds and 17% of the wind degree at high sea surface speeds. The accuracy of spaceborne GNSS-R sea surface wind direction retrievals can only reach 20° after rigorous data screening. Therefore, the accuracy of spaceborne GNSS-R sea surface wind field retrievals is not ideal. The main reason is that the sea surface wind field is derived from single-shot measurements by a directional antenna on a single satellite. This lacks measurement stability and reliability, making it difficult to meet the requirements for precise oceanographic research. Although some of these spaceborne GNSS-R missions consist of two or more satellites, there is no inter-satellite link for coordinated sea surface wind field detection. Therefore, a multi-satellite GNSS-R sea surface vector wind field detection system with joint observations is urgently needed to improve retrieval accuracy. Summary of the Invention

[0004] In order to solve the problems of low accuracy and poor reliability in the above-mentioned prior art of using a single GNSS-R satellite observation value to invert the sea surface vector wind field, the purpose of the present invention is to provide a multi-satellite collaborative GNSS-R sea surface vector wind field detection system and an on-orbit inversion method.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides a multi-satellite coordinated GNSS-R sea surface vector wind field detection system, comprising:

[0007] A master GNSS-R satellite (100) is used to receive, capture, and track navigation satellite reflection signals from mirror reflection points within a detection area, process delay Doppler maps of the area corresponding to the reflection signals in real time, record detection system status information, perform fusion processing on observation information from slave GNSS-R satellites, and invert vector wind fields; and

[0008] N slave GNSS-R satellites (200) are used to receive, capture, and track navigation satellite scattered signals from mirror reflection points within a detection area, process delay Doppler maps of areas corresponding to the scattered signals in real time, and record detection system status information;

[0009] The master GNSS-R satellite (100) is located at a central position, and the N slave GNSS-R satellites (200) are evenly distributed around the master GNSS-R satellite (100) and follow the satellite. The master GNSS-R satellite (100) and the N slave GNSS-R satellites (200) exchange information and transmit detection data via inter-satellite links.

[0010] In a second aspect, the present invention further provides an on-orbit inversion method for a multi-satellite coordinated GNSS-R sea surface vector wind field using the multi-satellite coordinated GNSS-R sea surface vector wind field detection system, comprising:

[0011] The navigation satellite direct signal and the corresponding reflected signal or scattered signal are synchronously processed on N+1 GNSS-R satellites to obtain the normalized delay power waveform Y i (τ j ), where τ j represents the time delay, j represents the number of time delay samples, i represents the GNSS-R satellite number, i=1,2,…,N+1;

[0012] The theoretical waveform W corresponding to N+1 GNSS-R satellites is obtained using the theoretical model matching inversion algorithm. i (τ j ,S) and W i (τ j ,θ), where S represents the sea surface wind speed and θ represents the sea surface wind direction;

[0013] The cost functions for delay waveform weighting are established on the primary GNSS-R satellite, which are:

[0014]

[0015]

[0016] Where Z represents the number of samples of the delay waveform, w i represents the weighted value determined by the signal-to-noise ratio of the delay waveforms corresponding to N+1 GNSS-R satellites;

[0017] The wind speed estimation value and wind direction estimation value are obtained on the primary GNSS-R satellite using the cost minimization function, which are:

[0018]

[0019]

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] According to the solution of the present invention, compared with the existing GNSS-R satellite detection mode of sea surface wind field, the multi-satellite collaborative GNSS-R sea surface vector wind field detection system is composed of a GNSS-R master satellite and N GNSS-R slave satellites. The phased array downward-looking antennas carried by N+1 GNSS-R satellites form a beam observation of the same area, wherein the master satellite receives the reflected signal of the mirror reflection point, and the slave satellite receives the scattered signal near the mirror reflection point. Then, the joint observation of multiple GNSS-R satellites is realized through the inter-satellite link, and the capture and tracking of multi-dimensional reflected signals and related scattered signals in the same area at the same time is realized. At the same time, all satellites process the received signals in real time on orbit and transmit them to the master satellite through the inter-satellite link for fusion processing, and finally realize the real-time inversion of the sea surface vector wind field, thereby effectively improving the inversion accuracy and reliability of the sea surface wind speed and wind direction.

[0022] According to one solution of the present invention, compared with the existing satellite-borne GNSS-R sea surface wind field detection technology, the gain of the downward-looking phased array antenna of the slave satellite is increased according to the difference between the scattered signal intensity and the reflected signal intensity. At the same time, the coordinates of the mirror reflection point are calculated in real time according to the positions of the GNSS satellite (navigation satellite) and the GNSS-R master satellite, and the information is broadcast to N slave satellites in a timely manner through the inter-satellite link, ensuring that the normal of the downward-looking phased array antenna scanning beam points to the mirror reflection point, thereby improving the signal-to-noise ratio of the reflected signal of the received mirror reflection point and the surrounding scattered signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0024] Figure 1 A schematic diagram illustrating the composition of a multi-satellite coordinated GNSS-R sea surface vector wind field detection system disclosed in an embodiment of the present invention;

[0025] Figure 2 A diagram schematically illustrates an application scenario of a multi-satellite coordinated GNSS-R sea surface vector wind field detection system disclosed in an embodiment of the present invention;

[0026] Figure 3 A schematic diagram illustrating the structure of a satellite-borne GNSS-R receiver 300 on a primary GNSS-R satellite disclosed in an embodiment of the present invention;

[0027] Figure 4 A schematic diagram illustrating the structure of a satellite-borne GNSS-R receiver 400 on a GNSS-R satellite disclosed in an embodiment of the present invention;

[0028] Figure 5 A flowchart schematically illustrates the on-orbit synchronous processing of navigation satellite reflected signals or scattered signals by a GNSS-R satellite according to an embodiment of the present invention;

[0029] Figure 6 The figure schematically shows a flowchart for implementing the on-orbit inversion method of the multi-satellite coordinated GNSS-R sea surface vector wind field disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The description of the embodiments in this specification should be combined with the corresponding drawings, which should be considered a complete part of this specification. In the drawings, the shapes and thicknesses of the embodiments may be exaggerated and indicated for simplicity or convenience. Furthermore, the various structural components in the drawings will be described separately. It is worth noting that components not shown in the drawings or not described in words are known to those of ordinary skill in the art.

[0031] The description of the embodiments herein and any references to directions and orientations are for ease of description only and are not to be construed as limiting the scope of the present invention. The following description of the preferred embodiments may involve combinations of features, which may exist independently or in combination. The present invention is not specifically limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0032] See also Figure 1The embodiment discloses a multi-satellite coordinated GNSS-R sea surface vector wind field detection system, which mainly includes: a master GNSS-R satellite 100 and N slave GNSS-R satellites 200. The master GNSS-R satellite 100 is located at the center, and the N slave GNSS-R satellites 200 are evenly distributed around the master GNSS-R satellite 100 to follow the main GNSS-R satellite 100. The master GNSS-R satellite 100 and the N slave GNSS-R satellites 200 exchange information and transmit detection data through inter-satellite links. Specifically, the master GNSS-R satellite 100 is used to receive, capture and track the navigation satellite reflection signal of the mirror reflection point in the detection area, process the delay Doppler map of the area corresponding to the reflection signal in real time, record the detection system status information, fuse the observation information of the slave GNSS-R satellite and invert the vector wind field. The N slave GNSS-R satellites 200 are used to receive, capture and track the navigation satellite scattered signal of the mirror reflection point in the detection area, process the delay Doppler map of the area corresponding to the scattered signal in real time, and record the detection system status information.

[0033] Furthermore, the master GNSS-R satellite 100 and the N slave GNSS-R satellites 200 realize the interaction and data transmission of information such as mirror reflection points and vector wind field inversion results within the detection area through inter-satellite links.

[0034] For example, Figure 2 The following schematically illustrates the application scenario of the multi-satellite coordinated GNSS-R sea surface vector wind field detection system disclosed in this embodiment. Figure 2 , the orbital altitudes of the master GNSS-R satellite (or master satellite) and the N slave GNSS-R satellites (or slave satellites) are both H, the master GNSS-R satellite is located at the center, and the N slave GNSS-R satellites are evenly distributed around the master GNSS-R satellite at a distance of 50 to 150 km. The medium-aperture downward-looking phased array antenna carried by the master GNSS-R satellite and the large-aperture downward-looking phased array antennas carried by the N slave GNSS-R satellites are both pointed to the mirror reflection point area of the sea surface detection area, wherein the medium-aperture downward-looking phased array antenna receives the reflected signal of the navigation satellite, and the large-aperture downward-looking phased array antenna receives the scattered signal of the navigation satellite within the reflection direction of ±20°. The master GNSS-R satellite transmits the sea surface vector wind field obtained by the inversion of the GNSS-R satellite group in this embodiment, including wind speed and wind direction information, to the relay communication satellite or ground station in real time.

[0035] See also Figure 1 In this embodiment, the master GNSS-R satellite 100 carries a satellite-borne GNSS-R receiver 300 , and the N slave GNSS-R satellites 200 carry a satellite-borne GNSS-R receiver 400 .

[0036] See also Figure 3 The satellite-borne GNSS-R receiver 300 of this embodiment includes: a small-aperture upward-looking phased array antenna 310, a medium-aperture downward-looking phased array antenna 320, and a GNSS-R electronics system 330. Specifically, the small-aperture upward-looking phased array antenna 310 is used to receive f L1 、f L2 The direct signals of the navigation satellites with two carrier frequencies have effective signal bandwidths of B and B respectively. L1 and B L2 The generated scanning beam is flexibly directed upward to the navigation satellite, the antenna polarization is right-hand circular polarization, and the antenna gain G1 is greater than 8dB. The medium-caliber downward-looking phased array antenna 320 is used to receive the navigation satellite reflection signal at the mirror reflection point in the detection area, and works at f L1 and f L2 Two carrier frequency bands, the effective signal bandwidth is B L1 and B L2 The generated scanning beam is flexibly pointed downward at the mirror reflection point in the sea surface detection area. The antenna polarization is left-hand circular polarization, and the antenna gain G2 is greater than 13dB. The GNSS-R electronics system 330 is used for positioning and solving the direct signal of the navigation satellite, solving the reflected signal of the navigation satellite, transmitting and exchanging inter-satellite link data information, fusing the observation information from the GNSS-R satellite 200, and calculating and retrieving the sea surface wind speed and direction on orbit. For example, f L1 is 1575.42MHz, f L2 It is 1227.60MHz.

[0037] Furthermore, the small-aperture upward-looking phased array antenna 310 simultaneously generates 4 to 16 scanning beams, the directions of which are determined by the real-time ephemeris of the navigation satellite. The medium-aperture downward-looking phased array antenna 320 simultaneously generates 4 to 16 scanning beams, the directions of which are determined by the position of the mirror reflection point calculated from the real-time ephemeris of the navigation satellite and the real-time ephemeris of the GNSS-R satellite.

[0038] See also Figure 4 The satellite-borne GNSS-R receiver 400 of this embodiment includes: a small-aperture upward-looking phased array antenna 310, a large-aperture downward-looking phased array antenna 420, and a GNSS-R electronics system 330. Specifically, the small-aperture upward-looking phased array antenna 310 is used to receive f L1 、f L2 The direct signals of the navigation satellites with two carrier frequencies have effective signal bandwidths of B and B respectively. L1 and B L2The generated scanning beam is flexibly pointed upward to the navigation satellite, the antenna polarization is right-hand circular polarization, and the antenna gain G1 is greater than 8dB. The large-aperture downward-looking phased array antenna 420 is used to receive the navigation satellite scattered signal at the mirror reflection point in the detection area, and works at f L1 and f L2 Two carrier frequency bands, the effective signal bandwidth is B L1 and B L2 The generated scanning beam is flexibly pointed downward to the mirror reflection point in the sea surface detection area. The antenna polarization is left-hand circular polarization, and the antenna gain G3 is greater than 18dB. The GNSS-R electronics system 330 is used for positioning and solving the direct signal of the navigation satellite, solving the scattered signal of the navigation satellite, and transmitting and interacting the data information of the inter-satellite link. For example, f L1 is 1575.42MHz, f L2 It is 1227.60MHz.

[0039] Furthermore, the small-aperture upward-looking phased array antenna 310 simultaneously generates 4 to 16 scanning beams, the directions of which are determined by the real-time ephemeris of the navigation satellite. The large-aperture downward-looking phased array antenna 420 simultaneously generates 4 to 16 scanning beams, the directions of which are determined by the real-time mirror reflection point positions transmitted by the primary GNSS-R satellite 100 via the intersatellite link.

[0040] The small-aperture upward-looking phased array antenna 310 , the medium-aperture downward-looking phased array antenna 320 , and the large-aperture downward-looking phased array antenna 420 are all used only for receiving signals.

[0041] The hardware structure, hardware composition, and functional roles of the small-aperture upward-looking phased array antenna 310 and the GNSS-R electronics system 330 in the onboard GNSS-R receivers 400 carried by the N slave GNSS-R satellites 200 of this embodiment are the same as those of the onboard GNSS-R receiver 300 carried by the master GNSS-R satellite 100.

[0042] Specifically, the GNSS-R electronics system 330 includes: a navigation satellite direct signal receiver 331, which is used to capture, track and solve navigation telegrams of navigation satellite direct signals, and orbit the master GNSS-R satellite 100 and the N slave GNSS-R satellites 200, and output information such as the position, orbit altitude, speed, orbit determination accuracy, and direct channel Doppler shift of the master GNSS-R satellite 100 and the N slave GNSS-R satellites 200; a navigation satellite reflected signal receiver 332, which is used to capture and track navigation satellite reflected signals (on the master GNSS-R satellite 100) or scattered signals (on the slave GNSS-R satellite 200), and coordinate the navigation satellite direct signals to complete the integration of the navigation satellite reflected signals or scattered signals with the locally generated Calculation of the signal replica in the time domain and frequency domain, and output of the delay Doppler map; a controller unit 333, used to estimate the delay and Doppler frequency shift of the navigation satellite reflected signal or scattered signal relative to the navigation satellite direct signal; a data storage unit 334, used to store the direct data, reflection data, delay Doppler map and detection system status information sampled and processed by the navigation satellite direct signal receiver 331 and the navigation satellite reflected signal receiver 332; an on-board computer unit 335, used to pre-process the delay Doppler map, and invert the wind speed and wind direction on-orbit in combination with the detection system status information; and an inter-satellite link unit 336, used to realize information interaction and detection data transmission between the master GNSS-R satellite 100 and the N slave GNSS-R satellites 200.

[0043] See also Figure 6 This embodiment also discloses a method for inverting the multi-satellite coordinated GNSS-R sea surface vector wind field on-orbit using the multi-satellite coordinated GNSS-R sea surface vector wind field detection system described above. The specific implementation process of this method includes the following steps:

[0044] The navigation satellite direct signal and the corresponding reflected signal or scattered signal are synchronously processed on N+1 GNSS-R satellites to obtain the normalized delay power waveform Y i (τ j ), where τ j represents the time delay, j represents the number of time delay samples, i represents the GNSS-R satellite number, i=1,2,…,N+1;

[0045] Then, the theoretical model matching inversion algorithm is used to obtain the theoretical waveform W corresponding to N+1 GNSS-R satellites. i (τ j ,S) and W i (τ j ,θ), where S represents the sea surface wind speed and θ represents the sea surface wind direction;

[0046] The cost functions for delay waveform weighting are established on the primary GNSS-R satellite, which are:

[0047]

[0048]

[0049] Where Z represents the number of samples of the delay waveform, w i represents the weighted value determined by the signal-to-noise ratio of the delay waveforms corresponding to N+1 GNSS-R satellites;

[0050] The wind speed estimation value and wind direction estimation value are obtained on the primary GNSS-R satellite using the cost minimization function, which are:

[0051]

[0052]

[0053] In one embodiment, see Figure 5 The specific implementation process or procedure of synchronously processing the navigation satellite direct signal and the corresponding reflected signal or scattered signal on the N+1 GNSS-R satellites includes:

[0054] The onboard GNSS-R receivers on the N+1 GNSS-R satellites are used to respectively detect f L1 and f L2 Processing the intermediate frequency digital signals of the navigation satellite direct signals and the corresponding reflected or scattered signals in the two carrier frequency bands, a single reading includes the binary intermediate frequency data of the orthogonal component I and the in-phase component Q of the signals captured by M array elements in the small-aperture upward-looking phased array antenna 310, the medium-aperture downward-looking phased array antenna 320, and the large-aperture downward-looking phased array antenna 420;

[0055] Then the binary intermediate frequency data is re-encoded, and the original 0 and 1 codes are translated into 1 and -1 codes. When the coherent integration time is T c When the reflected signal or scattered signal of the i-th GNSS-R satellite undergoes the n-th coherent integration, the amplitude of the k-th sample corresponding to the signal is:

[0056]

[0057] Among them, s is the signal component collected by a single array element, and e is the array element number;

[0058] In order to maximize the signal amplitude in the receiving beam direction, beamforming is used to combine the signals of each array element. The reflected signal or scattered signal after beamforming is:

[0059]

[0060] in, represents the phase difference of the e-th array element of the i-th GNSS-R satellite relative to the direction of the received signal; E represents the number of array elements.

[0061] In order to reduce the influence of thermal noise, the reflected signal or scattered signal after beamforming is coherently integrated, and the digital signal sampling frequency is f s , when T is obtained within the coherent integration time c ×f s sampling points, the signal amplitude after coherent integration is:

[0062]

[0063] The reflected or scattered signal is then compared to a locally generated replica of the direct signal from the navigation satellite. Perform cross-correlation in the frequency domain to obtain the composite power waveform, which is:

[0064]

[0065] Where j represents the number of delayed samples. The composite power waveform after coherent integration is subjected to non-coherent cumulative averaging to reduce the influence of speckle noise:

[0066]

[0067] Among them, N inc represents the number of non-coherent accumulations, T0 represents the start time of signal processing, and the corresponding composite power waveform is obtained as follows:

[0068] Y i (τ j )=Y i (T0+N inc ·T c / 2,τ j )=|y i (T0+N inc ·T c / 2,τ j )| 2 .

[0069] The multi-satellite collaborative GNSS-R sea surface vector wind field detection system and on-orbit inversion method of this embodiment can obtain high-precision information such as sea surface wind speed and wind direction. Specifically, based on the angle difference, signal-to-noise ratio difference and other information of the reflected signal at the sea surface mirror reflection point and the surrounding scattered signal, the configuration of the GNSS-R master satellite and the GNSS-R slave satellite and the downward-looking phased array antenna gain are reasonably designed to ensure the signal-to-noise ratio of the received reflected signal and the nearby scattered signal. Then, the satellite-borne GNSS-R receivers carried by the master satellite and the slave satellite group can realize the capture and tracking of multi-dimensional reflected signals in the same area and at the same time, and realize signal processing and theoretical waveform acquisition separately on each satellite. Finally, all waveform-related information is fused and processed by the on-board computer unit carried by the master satellite through the inter-satellite link, thereby obtaining high-precision sea surface vector wind field information. Therefore, the multi-satellite collaborative GNSS-R sea surface vector wind field detection system and on-orbit inversion method of this embodiment have the advantages of high inversion accuracy, high detection flexibility, strong reliability and low system cost.

[0070] The serial numbers of the above-mentioned steps involved in the method of the present invention do not mean the order of execution of the method. The execution order of each step should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-satellite coordinated GNSS-R sea surface vector wind field detection system, characterized by: include: A master GNSS-R satellite (100) is used to receive, capture, and track navigation satellite reflection signals from mirror reflection points within a detection area, process delay Doppler maps of the area corresponding to the reflection signals in real time, record detection system status information, perform fusion processing on observation information from the slave GNSS-R satellite (200), and invert a vector wind field; as well as N slave GNSS-R satellites (200) are used to receive, capture, and track navigation satellite scattered signals from mirror reflection points within a detection area, process delay Doppler maps of areas corresponding to the scattered signals in real time, and record detection system status information; The master GNSS-R satellite (100) is located at a central position, and the N slave GNSS-R satellites (200) are evenly distributed around the master GNSS-R satellite (100) to follow the satellite, and the master GNSS-R satellite (100) and the N slave GNSS-R satellites (200) exchange information and transmit detection data via inter-satellite links; The multi-satellite coordinated GNSS-R sea surface vector wind field on-orbit inversion method based on the multi-satellite coordinated GNSS-R sea surface vector wind field detection system includes: The navigation satellite direct signal and the corresponding reflected signal or scattered signal are synchronously processed on N+1 GNSS-R satellites to obtain the normalized delay power waveform Y i (τ j ), where τ j represents the time delay, j represents the number of time delay samples, i represents the GNSS-R satellite number, i=1,2,…,N+1; The theoretical waveform W corresponding to N+1 GNSS-R satellites is obtained using the theoretical model matching inversion algorithm. i (τ j ,S) and W i (τ j ,θ), where S represents the sea surface wind speed and θ represents the sea surface wind direction; The cost functions for delay waveform weighting are established on the primary GNSS-R satellite, which are: Where Z represents the number of samples of the delay waveform, w i represents the weighted value determined by the signal-to-noise ratio of the delay waveforms corresponding to N+1 GNSS-R satellites; The wind speed estimation value and wind direction estimation value are obtained on the primary GNSS-R satellite using the cost minimization function, which are:

2. The system according to claim 1, wherein: The master GNSS-R satellite (100) carries an onboard GNSS-R receiver (300), and the N slave GNSS-R satellites (200) carry an onboard GNSS-R receiver (400).

3. The system according to claim 2, characterized in that The satellite-borne GNSS-R receiver (300) comprises: A small-aperture upward-looking phased array antenna (310) is used to receive f L1 、f L2 The navigation satellite direct signal of two carrier frequencies generates a scanning beam that flexibly points upward toward the navigation satellite. The antenna polarization is right-hand circular polarization, and the antenna gain G1 is greater than 8dB. The medium-aperture downward-looking phased array antenna (320) is used to receive the navigation satellite reflection signal at the mirror reflection point in the detection area and simultaneously work at f L1 and f L2 Two carrier frequency bands, the generated scanning beam is flexibly pointed downward to the mirror reflection point in the sea surface detection area, the antenna polarization is left-hand circular polarization, and the antenna gain G2 is greater than 13dB; and The GNSS-R electronics system (330) is used for positioning and solving direct signals from navigation satellites, solving reflected signals from navigation satellites, transmitting and interacting with inter-satellite link data information, fusing and processing the observation information from the GNSS-R satellites (200), and calculating and reversing sea surface wind speed and direction on-orbit.

4. The system according to claim 3, characterized in that The medium-aperture downward-looking phased array antenna (320) generates 4 to 16 scanning beams simultaneously, and the directions of the scanning beams are determined by the positions of mirror reflection points calculated from the real-time ephemeris of the navigation satellite and the real-time ephemeris of the GNSS-R satellite.

5. The system according to claim 2, wherein: The satellite-borne GNSS-R receiver (400) comprises: A small-aperture upward-looking phased array antenna (310) is used to receive f L1 、f L2 The navigation satellite direct signal of two carrier frequencies generates a scanning beam that flexibly points upward toward the navigation satellite. The antenna polarization is right-hand circular polarization, and the antenna gain G1 is greater than 8dB. A large-aperture downward-looking phased array antenna (420) is used to receive scattered signals from navigation satellites at mirror reflection points within a detection area and simultaneously operate at f L1 and f L2 Two carrier frequency bands, the generated scanning beam is flexibly pointed downward to the mirror reflection point in the sea surface detection area, the antenna polarization is left-hand circular polarization, and the antenna gain G3 is greater than 18dB; and The GNSS-R electronics system (330) is used for positioning and calculating direct signals from navigation satellites, calculating scattered signals from navigation satellites, and transmitting and interacting inter-satellite link data information.

6. The system according to claim 5, characterized in that The large-aperture downward-looking phased array antenna (420) generates 4 to 16 scanning beams simultaneously, and the directions of the scanning beams are determined by the real-time mirror reflection point positions transmitted by the main GNSS-R satellite (100) via an intersatellite link.

7. The system according to claim 3 or 5, characterized in that The small-aperture upward-looking phased array antenna (310) generates 4 to 16 scanning beams simultaneously, and the directions of the scanning beams are determined by the real-time ephemeris of the navigation satellite.

8. The system according to claim 3 or 5, characterized in that The GNSS-R electronics system (330) comprises: A navigation satellite direct signal receiver (331) is used for capturing, tracking and interpreting navigation messages of the navigation satellite direct signal, and for determining the orbits of the master GNSS-R satellite (100) and the N slave GNSS-R satellites (200); A navigation satellite reflected signal receiver (332) is used to capture and track the navigation satellite reflected signal or scattered signal, coordinate the navigation satellite direct signal, complete the calculation of the navigation satellite reflected signal or scattered signal and the locally generated signal replica in the time domain and frequency domain, and output a delay Doppler map; A controller unit (333) is used to estimate the time delay and Doppler frequency shift of the navigation satellite reflected signal or scattered signal relative to the navigation satellite direct signal; A data storage unit (334) is used to store direct data, reflected data, a delay Doppler map, and detection system status information that are sampled and processed by the navigation satellite direct signal receiver (331) and the navigation satellite reflected signal receiver (332); An onboard computer unit (335) is used to pre-process the delay-Doppler map and invert the wind speed and direction on-orbit in combination with the detection system status information; and An intersatellite link unit (336) is used to implement information interaction and detection data transmission between the master GNSS-R satellite (100) and the N slave GNSS-R satellites (200).

9. The system according to claim 1, wherein: The process of synchronously processing the navigation satellite direct signal and the corresponding reflected signal or scattered signal on N+1 GNSS-R satellites includes: The onboard GNSS-R receivers on the N+1 GNSS-R satellites are used to respectively detect f L1 and f L2 Processing the intermediate frequency digital signals of the navigation satellite direct signals and the corresponding reflected or scattered signals in the two carrier frequency bands, a single reading includes the binary intermediate frequency data of the orthogonal component I and the in-phase component Q of the signals captured by M array elements in the small-aperture upward-looking phased array antenna, the medium-aperture downward-looking phased array antenna, and the large-aperture downward-looking phased array antenna; The binary intermediate frequency data is re-encoded, and the original 0 and 1 codes are translated into 1 and -1 codes. When the coherent integration time is T c When the reflected signal or scattered signal of the i-th GNSS-R satellite undergoes the n-th coherent integration, the amplitude of the k-th sample corresponding to the signal is: Among them, s is the signal component collected by a single array element, and e is the array element number; Beamforming is used to combine the signals of each array element. The reflected signal or scattered signal after beamforming is: in, represents the phase difference of the e-th array element of the i-th GNSS-R satellite relative to the direction of the received signal; E represents the total number of array elements; The reflected signal or scattered signal after beamforming is processed by coherent integration, and the digital signal sampling frequency is f s , when T is obtained within the coherent integration time c ×f s sampling points, the signal amplitude after coherent integration is: The reflected or scattered signal is then compared to a locally generated replica of the direct signal from the navigation satellite. Perform cross-correlation in the frequency domain to obtain the composite power waveform, which is: Where j represents the number of delayed samples; the composite power waveform after coherent integration is subjected to non-coherent cumulative averaging: Among them, N inc represents the number of non-coherent accumulations, T0 represents the start time of signal processing, and the corresponding composite power waveform is obtained as follows: Y i (τ j )=Y i (T0+N inc ·T c / 2,τ j )=|y i (T0+N inc ·T c / 2,τ j )| 2 。

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