Calculation Method of Thermospheric Horizontal Regional Wind Field for Multi-Station Incoherent Scatter Radar

Abstract

The present invention belongs to the field of signal and information processing, and particularly relates to a method for calculating the thermospheric horizontal regional wind field of a multi-station incoherent scatter radar, aiming to solve the problem that the prior art cannot detect and calculate the wind fields at different positions in the horizontal region of low-latitude areas. This method includes: calculating the polarization angles of the transmitting station and the receiving station, and then calculating the included angle between the transmitting beam and the receiving beam to obtain the line-of-sight velocity of each station; connecting the coordinates of the transmitting station and each receiving station, and establishing a geometric transformation relationship in combination with the position of the detected scattering point to obtain the backscattering wave vector of the transmitting station and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point; obtaining the vector velocity of multi-station collaborative detection of the same scattering volume; determining the diffusion velocity corresponding to the vector velocity, calculating the thermospheric meridional wind field, and combining the distribution of different scattering points in the horizontal plane to obtain the thermospheric horizontal regional wind field. The present invention realizes the detection and calculation of the wind fields at different positions in the horizontal region.

Description

Technical Field

[0001] The present invention belongs to the field of signal and information processing, and particularly relates to a method, a system, an electronic device, and a computer-readable storage medium for calculating the thermospheric horizontal regional wind field of a multi-station incoherent scatter radar. Background Art

[0002] The wind field controls a large part of the dynamics in the thermospheric atmosphere and serves as a coupling agent between the neutral component and plasma in the ionosphere-thermosphere system (see reference: Wang, W., Burns, A. G., & Liu, J. (2021). Upper Thermospheric Winds. In Upper Atmosphere Dynamics and Energetics. American Geophysical Union, 41–63. https: / / doi.org / 10.1002 / 9781119815631.CH3). It is the main regulator and redistributor of mass, momentum, and energy within the ionosphere-thermosphere system and thus plays an important role in determining the geospace weather at all latitudes. In the past few decades, countries have retrieved the wind field by using spaceborne optical detection instruments based on the airglow in the ultraviolet band emitted by the thermospheric atmosphere and obtained a batch of wind field observation data. Typical spaceborne wind measurements include: (1) The Wind Imaging Interferometer (WINDII) and the High-Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) (see reference: Hays, P. B., Abreu, V. J., Dobbs, M. E., Gell, D. A., Grassl, H. J., & Skinner, W. R. (1993). The high-resolution doppler imager on the Upper Atmosphere Research Satellite. Journal of Geophysical Research, 98(D6), 10713. https: / / doi.org / 10.1029 / 93JD00409) obtained the wind field from the MLT to the upper thermospheric altitude by remote sensing; (2) The Timed Doppler Interferometer (TIDI) of Thermosphere and Mesosphere Energetics Dynamics (TIMED) (see reference: Skinner, W. R., Niciejewski, R. J., Killeen, T. L., Solomon, S. C., Gablehouse, D., Wu, Q., et al. (2003). Operational performance of the TIMED Doppler Interferometer (TIDI). In A. M. Larar, J. A. Shaw, & Z. Sun (Eds.)5157, (47).International Society for Optics and Photonics. https: / / doi.org / 10.1117 / 12.503727) Remote sensing was used to detect the wind field in the MLT region, studying the global distribution of the thermospheric wind field and the relationships between the wind field, solar activity, and geomagnetic activity; (3) Challenging Minisatellite Payload (CHAMP) (for reference: Reigber, C., Lühr, H., & Schwintzer, P. (2002). CHAMP mission status. Advances in Space Research, 30(2), 129–134. https: / / doi.org / 10.1016 / S0273-1177(02)00276-4), using the accelerometer data of the CHAMP satellite, the thermospheric wind field was deduced and the distribution characteristics of the thermospheric wind field on a global scale were demonstrated; (4) Gravity field and steady-state Ocean Circulation Explorer (GOCE) (for reference: Doornbos, E., Bruinsma, S., Fritsche, B., Visser, P., Van Den IJssel, J., Encarnacao, J. T., & Kern, M. (2013). Air Density and Wind Retrieval Using GOCE Data. ESA Living Planet Symposium. Proceedings of the Conference Held on 9-13 September 2013 at Edinburgh in United Kingdom. ESA SP-722. 2-13, p.7, 722, 7) measured the global in-situ cross-track winds in the thermosphere; (5) The Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI) on the Ionospheric Connection Explorer (ICON) (for reference: Englert, C. R., Harlander, J. M., Brown, C. M., Marr, K. D., Miller, I. J., Stump, J. E., et al. (2017). Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration.SpaceScience Reviews, 212(1–2), 553–584. https: / / doi.org / 10.1007 / s11214-017-03 58-4) The wind fields from the MLT to the thermosphere below mid-latitudes were measured. However, these missions mainly measured the climatological variations of the global wind fields, usually with fixed local time coverage at the same location and without continuous time coverage, making it impossible to analyze the diurnal variations of the wind fields, etc.

[0003] In existing ground-based detections, the incoherent scatter radar is the most powerful means of detecting the thermospheric wind field, and it can observe the wind field at a fixed location. The incoherent scatter radar obtains multi-parameter information of the ionosphere by transmitting high-power electromagnetic waves and receiving the weak Thomson scatter echoes of electrons in the ionosphere (for references: Evans, J. V. (1969), Theory and practice of ionosphere study by Thomson scatter radar, Proceedings of the IEEE, 57(4), 496–530. https: / / doi.org / 10.1109 / proc.1969.7005; Mathews, J.D. (1984), The incoherent scatter radar as a tool for studying the ionospheric D-region, J. Atmos. Sol. Terr. Phys., 46(11), 975–986. https: / / doi.org / 10.1016 / 0021-9169(84)90004-7). The European EISCAT Association (European Incoherent SCATter) operates three ISR radars, namely the UHF radar, the VHF radar, and the Svalbard radar (for references: Schlegel K, Moorcroft, D. R. (1989), EISCAT as a tristatic auroral radar. Journal of Geophysical Research Space Physics, 94(A2):1430-1438. https: / / doi.org / 10.1029 / ja094ia02 p01430; Wannberg, G., Wolf, I., et al. (1997). The EISCAT Svalbard radar: A case study in modern incoherent scatter radar system design. Radio Science, 32(6), 2283–2307. https: / / doi.org / 10.1029 / 97rs01 803). Among them, the UHF radar is a multi-station parabolic incoherent scatter radar, with its transmitting station located in Tromsø and receiving stations located in Tromsø, Kiruna, and Sodankyla.The EISCAT incoherent scatter radar has also observed the wind field in the high-latitude region of Europe. It is an important data source for polar dynamics research. The study of the climate behavior of the wind field's dependence on seasons and solar activity, and further improvement of various models through observational data (for references: Griffin, E. M., Mueller-Wodarg, I.C. F., Aruliah, A., Aylward, A. (2004a). Comparison of high-latitude thermospheric meridional winds I: optical and radar experimental comparisons. Annales Geophysicae, 22(3). https: / / doi.org / 10.5194 / angeo-22-849-2004; Griffin, E. M., Aruliah, A., Mueller-Wodarg, I. C. F., Aylward, A. (2004b). Comparison of high-latitude thermospheric meridional winds II: combined FPI, radar and model Climatologies. Annales Geophysicae, 22(3). https: / / doi.org / 10.5194 / angeo-22-863-2004). Its radar uses a parabolic antenna and scans by mechanical rotation, with very low efficiency and the limitation of being unable to continuously observe for a long time.

[0004] With the development of radar technology, phased array antennas have come into view due to their advantages such as large-range rapid scanning, fine scanning, flexible controllability, and long-time continuous observation. Incoherent scatter radars have started to use phased array antennas to replace traditional parabolic antennas. In the 21st century, the United States carried out a technological innovation and proposed a new type of modular active phased array radar project, the Advanced Modular Incoherent Scatter Radar (AMISR). By controlling the radar beam through software, the beam direction can be quickly switched within the microsecond level, greatly improving the problem of time ambiguity caused by the mechanical rotation of the traditional parabolic radar to change the beam direction (for reference: Valentic T., Buonocore J., Cousins M., Heinselman C., Jorgensen J. & Kelly J. et al, “AMISR the advanced modular incoherent scatter radar,” IEEE International Symposium on Phased Array Systems & Technology, Waltham, MA, USA, pp. 659 - 663, 2013, DOI: 10.1109 / ARRAY.2013.6731908). However, all current AMISR radars are single-transmitter and single-receiver radars and cannot perform three-station collaborative observations. Based on its phased array antenna system, it can conduct continuous observations. However, the radar is located in high-latitude regions, and its conventional observations are mainly focused on the low-altitude E-region wind field in high-latitude regions and are the average wind field within a certain horizontal plane range.

[0005] Meanwhile, in Hainan, China, a three-station high-power phased array incoherent scatter radar has been completed. It is transmitted from the Sanya Station in Hainan, and received by the Sanya, Fukang, and Wenchang stations (for references, see: Yue, X., Wan, W., Ning, B., Jin, L., Ding, F., Zhao, B., et al. (2022). Development of the Sanya incoherent scatter radar and preliminary results. Journal of Geophysical Research: Space Physics, 127, e2022JA030451. https: / / doi.org / 10.1029 / 2022JA0; Yue, X., Ning, B., Jin, L., Ding, F., Ke, C., Wang, J., et al. (2024). The Sanya incoherent scatter radar tristatic system and initial experiments. Space Weather, 22, e2024SW003963. https: / / doi.org / 10.1029 / 2024SW003963). The multi-station phased array incoherent scatter radar with 1 transmitter and 3 receivers in Hainan can vectorially measure the ionospheric drift velocity and provide multi-level, multi-parameter, and high-precision ionospheric parameters. It has become the first multi-station phased array incoherent scatter radar with 1 transmitter and 3 receivers in the low-latitude region.

[0006] Currently, through observation means such as satellites, the large-scale wind field can be detected at fixed local times, but continuous detection cannot be carried out for specific regions. Therefore, previous thermospheric wind field observations were generally the average wind field within a certain spatial range, and there is currently no observation that gives the wind field variation in a certain horizontal region. Based on the satellite wind field data averaged over a large range, climatological analysis of the wind field can be carried out, but synoptic analysis such as diurnal variation cannot be carried out, and even less can the small-scale structural regional variation within the horizontal range be obtained.

[0007] The EISCAT multi-station incoherent scatter radar uses a parabolic antenna and conducts beam scanning through mechanical rotation, resulting in poor observational time resolution. Therefore, it rarely conducts observations and research on the thermospheric wind field in the horizontal region. At the same time, the EISCAT incoherent scatter radar is mainly concentrated in high-latitude regions, lacking observational data on the thermospheric wind field in low-latitude regions. The ionospheric dynamic processes at different latitudes are different, and different backgrounds and geomagnetic configurations have a significant impact on the wind field. Previous studies have mainly focused on high-latitude regions, and the propagation law of the thermospheric wind field in low-latitude regions is not yet clear.

[0008] The AMISR in the United States, due to its single-transmitter and single-receiver design, can only detect the average wind field within a certain horizontal range at low altitudes and cannot detect the wind fields at different positions in the horizontal region. At the same time, it mainly focuses on the horizontal wind field in the low-altitude E region.

[0009] The Hainan three-station incoherent scatter radar can obtain the horizontal wind field within a certain area based on its phased array system and three-station collaborative detection system. Therefore, the present invention proposes a method for calculating the thermospheric horizontal region wind field of a multi-station incoherent scatter radar. Summary of the Invention

[0010] To solve the above problems in the prior art, that is, to solve the problem that the prior art cannot detect and calculate the wind fields at different positions in the horizontal region of low-latitude regions, in the first aspect of the present invention, a method for calculating the thermospheric horizontal region wind field of a multi-station incoherent scatter radar is proposed. The method includes:

[0011] Based on the parameters of the transmitting beam and receiving beam of the multi-station incoherent scatter radar, calculate the polarization angles of the transmitting station and receiving stations; according to the relationship between the polarization angles, calculate the angle between the transmitting beam and the receiving beam; the parameters include azimuth angle and elevation angle.

[0012] Combined with the angle, according to the echo Doppler frequency shift amount, further calculate the line-of-sight velocities of each station in the coordinate system centered on the scattering point, that is, the line-of-sight velocities in different directions within the same scattering volume.

[0013] Connect the coordinates of the transmitting station and each receiving station, and establish a geometric transformation relationship in combination with the position of the detected scattering point, so as to obtain the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point.

[0014] Based on the line-of-sight velocities in the coordinate system centered on the scattering point, the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point, and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point, combined with the relationship formula between the line-of-sight velocity and the vector velocity, obtain the vector velocity of multi-station collaborative detection within the same scattering volume.

[0015] Determine the diffusion velocity corresponding to the vector velocity of the multi-station collaborative detection of the same scattering volume according to the community height; calculate the thermospheric meridional wind field based on the diffusion velocity, and combine the distribution of different scattering points in the horizontal plane to obtain the thermospheric horizontal regional wind field.

[0016] In some preferred embodiments, the polarization angles of the transmitting station and the receiving station are calculated by the following method:

[0017]

[0018] Wherein, 、 represent the polarization angles of the transmitting station and the receiving station respectively, is the angle between the horizontal direction and the electric field direction of the transmitting beam, , , represent the three components corresponding to the transmitting beam vector respectively, , , represent the three components corresponding to the receiving beam vector respectively, and represent the azimuth angle and the elevation angle corresponding to the transmitting beam respectively, and represent the azimuth angle and the elevation angle corresponding to the receiving beam respectively.

[0019] In some preferred embodiments, the angle between the transmitting beam and the receiving beam is calculated by the following method:

[0020]

[0021] Wherein, represents the angle between the transmitting beam and the receiving beam.

[0022] In some preferred embodiments, in combination with the angle, according to the echo Doppler frequency shift amount, the line-of-sight velocity of each station in the coordinate system centered on the scattering point is further calculated by the following method:

[0023]

[0024] Wherein, represents the echo Doppler frequency shift amount, represents the line-of-sight velocity of each station in the coordinate system centered on the scattering point, is the wavelength.

[0025] In some preferred embodiments, if the multi-station incoherent scatter radar is one-transmitter and three-receivers, where one station is both a transmitter and a receiver, this station is regarded as the first station, and the remaining two stations are only receivers, regarded as the second station and the third station respectively. Then, the method for obtaining the backscattering wave vector of the transmitter in the coordinate system centered on the scattering point and the scattering wave vectors of each receiver in the coordinate system centered on the scattering point is as follows:

[0026] Perform beam coordinate transformation for each station, and combine the transformation relationships between the longitude and latitude geographic coordinate system and the geocentric coordinate system of each station, and between the geocentric coordinate system and the coordinate system centered on the scattering point, to obtain the backscattering wave vector of the transmitter in the coordinate system centered on the scattering point and the scattering wave vectors of each receiver in the coordinate system centered on the scattering point:

[0027]

[0028]

[0029] Among them, 、 represent the scattering wave vectors of each receiver in the coordinate system centered on the scattering point, that is, the scattering wave vector of the second station in the coordinate system centered on the scattering point and the scattering wave vector of the third station in the coordinate system centered on the scattering point. represents the backscattering wave vector of the transmitter in the coordinate system centered on the scattering point, that is, the vector between the first station and the scattering point. represents the distance between the first station and the scattering point. represents the distance between the second station and the scattering point. represents the distance between the third station and the scattering point. and represent the vectors between the second station and the scattering point, and between the third station and the scattering point.

[0030] In some preferred embodiments, if the multi-station incoherent scatter radar is one-transmitter and three-receivers, the relationship between the line-of-sight velocity and the vector velocity is:

[0031]

[0032] Among them, , , respectively represent the line-of-sight velocities of the first station, the second station, and the third station. represents the vector velocity of the three-station collaborative detection of the same scattering volume.

[0033] In some preferred embodiments, the method for obtaining the thermospheric horizontal regional wind field is as follows:

[0034] The vector velocities in different directions within the same scatterer can be further used to calculate the wind fields in different directions within the same scatterer. By combining the distributions of different scatter points in the horizontal plane, the wind field in the horizontal region of the thermosphere can be obtained.

[0035] In a second aspect of the present invention, a multi-station incoherent scatter radar thermospheric horizontal region wind field calculation system is proposed. The system includes:

[0036] An included angle calculation module configured to calculate the polarization angles of the transmitting station and the receiving station based on the parameters of the transmitting beam and the receiving beam of the multi-station incoherent scatter radar; calculate the included angle between the transmitting beam and the receiving beam according to the relationship between the polarization angles; the parameters include azimuth angle and elevation angle;

[0037] A line-of-sight velocity acquisition module configured to combine the included angle and calculate the line-of-sight velocities of each station in the coordinate system centered on the scatter point according to the echo Doppler frequency shift amount, that is, the line-of-sight velocities in different directions within the same scatter volume;

[0038] A wave vector calculation module configured to connect the coordinates of the transmitting station and each receiving station, and establish a geometric transformation relationship in combination with the position of the detected scatter point, so as to obtain the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point and the scatter wave vectors of each receiving station in the coordinate system centered on the scatter point;

[0039] A vector velocity calculation module configured to obtain the vector velocity of multi-station collaborative detection within the same scatter volume based on the line-of-sight velocity in the coordinate system centered on the scatter point, the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point, and the scatter wave vectors of each receiving station in the coordinate system centered on the scatter point, in combination with the relationship formula between the line-of-sight velocity and the vector velocity;

[0040] A wind field acquisition module configured to determine the diffusion velocity corresponding to the vector velocity of multi-station collaborative detection within the same scatter volume according to the common body height; calculate the thermospheric meridional wind field based on the diffusion velocity, and combine the distributions of different scatter points in the horizontal plane to obtain the wind field in the horizontal region of the thermosphere.

[0041] In a third aspect of the present invention, an electronic device is proposed, including: at least one processor; and a memory communicatively connected to at least one of the processors; wherein, the memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned multi-station incoherent scatter radar thermospheric horizontal region wind field calculation method.

[0042] In a fourth aspect of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores computer instructions for being executed by a computer to implement the above-mentioned method for calculating the thermospheric horizontal region wind field of a multi-station incoherent scatter radar.

[0043] Advantages of the present invention:

[0044] The present invention realizes the detection and calculation of wind fields at different positions in the horizontal region.

[0045] (1) The present invention uses a multi-station (e.g., three-station) incoherent scatter radar to extract the horizontal region wind field in the low-latitude region of the Asian sector. For the first time, it can quantitatively calculate parameters very important for ionospheric detection, such as the horizontal region wind field in the low-latitude region, providing an effective data source for small-scale structure analysis in the horizontal region. Currently, only the average wind field of a certain horizontal region can be obtained through a single-station incoherent scatter radar, and many small-scale structures are submerged. However, multi-station collaborative observation can obtain wind field data at different positions in the horizontal plane, and certain small-scale structures can be obtained;

[0046] (2) Currently, only profile data below the peak electron concentration and total electron content data can be obtained through an ionosonde or a GNSS receiver, lacking necessary dynamic information and unable to study the rapidly changing ionospheric physical processes and their evolution mechanisms in the horizontal region. The horizontal region wind field data obtained by a multi-station incoherent scatter radar can be used to study various atmospheric wave uploads and ionospheric responses, coupling and energy transfer mechanisms, and ionospheric / thermospheric temperature, density, composition, wind field, electric field changes, particle upflows, and magnetospheric coupling mechanisms during magnetic storms.

[0047] (3) Utilizing the geographical advantage of the Sanya incoherent scatter detection system located at low geomagnetic latitudes and the technical advantage of continuous observation ability to obtain horizontal region wind field data and study the variation of the wind field with different positions in the horizontal plane will help reveal the fine variations in the thermosphere. Description of the Drawings

[0048] Other features, objectives, and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings.

[0049] Figure 1 is a schematic flowchart of the method for calculating the thermospheric horizontal region wind field of a multi-station incoherent scatter radar according to an embodiment of the present invention;

[0050] Figure 2 is a schematic diagram showing the variation of vector velocities in different horizontal regions with date according to an embodiment of the present invention;

[0051] Figure 3It is a schematic diagram showing the variation of the meridional wind in different horizontal regions of an embodiment of the present invention with the date. Detailed implementation manners

[0052] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] The following further elaborates on the present application with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the relevant invention and not for limiting the invention. Additionally, it should be noted that for ease of description, only the parts related to the relevant invention are shown in the drawings.

[0054] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0055] The method for calculating the thermospheric horizontal region wind field of the multi-station incoherent scatter radar of the present invention, as Figure 1 shown, includes the following steps:

[0056] Based on the parameters of the transmitting beam and receiving beam of the multi-station incoherent scatter radar, calculate the polarization angles of the transmitting station and receiving stations; according to the relationship between the polarization angles, calculate the angle between the transmitting beam and the receiving beam; the parameters include azimuth angle and elevation angle.

[0057] Combined with the angle, according to the echo Doppler frequency shift amount, further calculate the line-of-sight velocities of each station in the coordinate system centered on the scattering point, that is, the line-of-sight velocities in different directions within the same scattering volume.

[0058] Connect the coordinates of the transmitting station and each receiving station, and establish a geometric transformation relationship in combination with the position of the detected scattering point, so as to obtain the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point.

[0059] Based on the line-of-sight velocities in the coordinate system centered on the scattering point, the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point, and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point, combined with the relationship formula between the line-of-sight velocity and the vector velocity, obtain the vector velocity of multi-station collaborative detection within the same scattering volume.

[0060] Determine the diffusion velocity corresponding to the vector velocity of the multi-station collaborative detection of the same scattering volume according to the community height; calculate the thermospheric meridional wind field based on the diffusion velocity, and combine the distribution of different scattering points in the horizontal plane to obtain the thermospheric horizontal regional wind field.

[0061] To more clearly illustrate the method for calculating the thermospheric horizontal regional wind field of the multi-station incoherent scatter radar of the present invention, the following details each step in an embodiment of the method of the present invention with reference to the accompanying drawings.

[0062] Based on a multi-station phased array incoherent scatter radar (in the following embodiments, a three-station incoherent scatter radar is taken as an example. The three stations are Sanya Station, Danzhou Station (i.e., Fucheng Station), and Wenchang Station. Among them, Sanya Station is both a transmitting station and a receiving station, serving as the first station, Danzhou Station is a receiving station, serving as the second station, and Wenchang Station is a receiving station, serving as the third station), by designing different detection experiments, calculate the horizontal wind fields of different scattering volumes in different regions. Without making any assumptions, use the multi-station collaborative observation data to calculate the line-of-sight velocities in different directions within the same scattering volume to obtain the vector velocity within the same scattering volume, and accordingly calculate the vector velocities in different scattering volumes. Through the obtained vector velocities, further calculate the wind field data in the horizontal region. Specifically as follows:

[0063] Based on the parameters of the transmitting beam and receiving beam of the multi-station incoherent scatter radar, calculate the polarization angles of the transmitting station and receiving station; according to the relationship between the polarization angles, calculate the included angle between the transmitting beam and the receiving beam; the parameters include azimuth angle and elevation angle.

[0064] For the multi-station collaborative observation data, first determine the experimental mode according to the observation target. Taking three stations as an example, generally for three-station observation, the spatial synchronous detection of the detection target is achieved by determining the azimuth angles and elevation angles of the transmitting beam and receiving beam. For incoherent scatter, the scattering cross-section includes a polarization angle term. Generally, when the polarization angle is equal to 90°, the polarization angle is optimal. However, for three-station observation, it is impossible to achieve the optimal polarization angle of 90° for both the transmitting station and the receiving station at the same time, and the optimal polarization angle for the collaborative detection of the transmitting station and the receiving station needs to be determined. In this embodiment, the polarization angle formulas for the transmitting station and the receiving station are as follows:

[0065]

[0066] Among them, 、 respectively represent the polarization angles of the transmitting station and the receiving station, is the included angle between the horizontal direction and the electric field direction of the transmitting beam, , , respectively represent the three components corresponding to the transmitting beam vector, , , respectively represent the three components corresponding to the received beam vector, and respectively represent the azimuth angle and elevation angle corresponding to the transmitted beam, and respectively represent the azimuth angle and elevation angle corresponding to the received beam.

[0067] Based on this, the included angle between the transmitted beam and the received beam can be further obtained, and the relationship is as follows:

[0068]

[0069] Wherein, represents the included angle between the transmitted beam and the received beam.

[0070] Combined with the included angle, according to the echo Doppler frequency shift amount, the line-of-sight velocity of each station in the coordinate system centered on the scattering point can be further calculated, that is, the line-of-sight velocities in different directions within the same scattering volume;

[0071] Within a certain scanning range, the beams of multiple stations are simultaneously directed at the same position for detection. Therefore, the line-of-sight velocities in each direction within the same scattering volume can be obtained through least-square fitting. In this embodiment, according to the non-coherent scattering radar detection principle, the echo Doppler frequency shift amount of the center frequency of the scattering signal relative to the radar transmission frequency, and then the line-of-sight velocity is obtained as:

[0072]

[0073] Wherein, represents the line-of-sight velocity of each station in the coordinate system centered on the scattering point, is the wavelength.

[0074] After obtaining the line-of-sight velocity, it is necessary to further calculate the scattering wave vectors of the transmitting station and the receiving station. When performing co-body detection, it needs to be converted to the coordinate system centered on the scattering volume for calculation. Therefore, after obtaining the coordinates in the geocentric coordinate system, it is necessary to convert them to the coordinate system centered on the scattering point. Specifically:

[0075] Combined with the conversion relationship between the longitude and latitude geographical coordinate system of each station and the geocentric coordinate system, and the conversion relationship between the geocentric coordinate system and the coordinate system centered on the scattering point, the coordinate conversion of the beams in different directions within the same scattering volume is performed to obtain the beams in the coordinate system centered on the scattering point.

[0076] Taking three stations as an example, according to the longitude and latitude geographical coordinates of the three stations, the coordinates of the three stations in the geocentric coordinate system can be obtained:

[0077]

[0078] Among them, , , respectively represent the coordinates of the first station, the second station, and the third station in the geocentric coordinate system;

[0079] After obtaining the coordinates in the geocentric coordinate system, it is necessary to convert them into a coordinate system centered on the scatter point respectively, and the corresponding transformation matrix can be expressed as:

[0080]

[0081]

[0082]

[0083] Among them, , , represent the transformation matrices of the first station, the second station, and the third station.

[0084] After obtaining the coordinate system centered on the scatter point, the transmitting station and the receiving station are analyzed in the same coordinate system. Here, the coordinate positions of the transmitting station and the receiving station are fixed. According to the previous analysis, the direction of the received scattered beam can be obtained at .

[0085] In addition, after obtaining the coordinate system centered on the scatter point, it is necessary to connect the coordinates of the transmitting station and the receiving station, and construct a triangular geometric relationship according to the detected scatter point, and establish a geometric transformation relationship to obtain the post-image scattered wave vector of the transmitting station and the scattered wave vector of the receiving station. Taking the three stations as an example, the backscattered wave vector of the transmitting station (the vector between the first station and the scatter point), the scattered beam of the Danzhou receiving station and the scattered wave vector of the Wenchang receiving station can be obtained. Here, it is expressed as:

[0086]

[0087]

[0088] Among them, represents the distance between the first station and the scatter point, represents the distance between the second station and the scatter point, represents the distance between the third station and the scatter point, and Denote the vectors between the second station and the scattering point, and between the third station and the scattering point. For other multi-station non-coherent scatter radars, the above formula can be dynamically adjusted according to the number of receiving stations to obtain the scattered wave vectors of the receiving stations. Specifically, obtain the vectors between the newly added receiving stations and the scattering point, and the distances between the receiving stations and the scattering point, and replace the corresponding parameters in the above formula to obtain the scattered wave vectors of the newly added receiving stations.

[0089] Based on the line-of-sight velocity in the coordinate system centered at the scattering point, the backscattered wave vector of the transmitting station in the coordinate system centered at the scattering point, and the scattered wave vectors of each receiving station in the coordinate system centered at the scattering point, combined with the relationship between the line-of-sight velocity and the vector velocity, obtain the vector velocity for multi-station collaborative detection of the same scattering volume;

[0090] In this embodiment, taking three stations as an example, according to the above geometric relationship, the relationship between the line-of-sight velocity and the vector velocity can be established as follows:

[0091]

[0092] Among them, , , respectively represent the line-of-sight velocities of the first station (i.e., Sanya Station), the second station (Danzhou Station), and the third station (Wenchang Station), represents the vector velocity for three-station collaborative detection of the same scattering volume, represents the position of the scattering point, S represents the position of the first station, A represents the intersection of the scattering beam vectors of the first and second stations with the ground, and B represents the intersection of the scattering beam vectors of the first and third stations with the ground. This relationship can be adjusted according to the number of receiving stations: that is, in other embodiments, referring to the above formula, according to the scattered wave vectors of the receiving stations, the relationship between the line-of-sight velocity and the vector velocity can be established.

[0093]

[0094] Among them, represents a 3 × 3 matrix, and each row is , and .

[0095] According to the common body height, determine the diffusion velocity corresponding to the vector velocity for multi-station collaborative detection of the same scattering volume; based on the diffusion velocity, calculate the thermospheric meridional wind field, and combined with the distribution of different scattering points in the horizontal plane, obtain the thermospheric horizontal regional wind field.

[0096] In this embodiment, after obtaining the vector velocity, the corresponding diffusion velocity needs to be determined according to the common body height. After obtaining the diffusion velocity, according to the formula, the thermospheric meridional wind can be expressed as:

[0097]

[0098] Among them, represents the meridional wind, that is, the wind fields in all directions within the same scatterer, represents the velocity along the parallel magnetic field lines at different points within the corresponding horizontal range, represents the diffusion velocity, represents the magnetic dip angle at different points within the corresponding horizontal range.

[0099] Through the vector wind field data in all directions within the same scatterer and the distribution of different scatter points in the horizontal plane, the wind field data of the horizontal area can be obtained.

[0100] To prove the effectiveness of the present invention, the method of the present invention is verified as follows:

[0101] The Sanya main station uses 11-beam circular scanning detection, and two receiving stations follow the main station for scanning detection. The common body height detected here is 400 km. Through collaborative detection, the velocity vectors and wind fields at different positions within the scanning range of the 11 beams of the main station can be detected. For example, Figure 2 、 3 As shown, Ve represents the eastward velocity, Vn represents the northward velocity, Vv represents the vertical velocity, and the abscissa is from November 14th to 20th, 2023. This time period is a magnetic quiet period. It can be seen from the figure that the three-dimensional vector velocity shows obvious periodic changes, and there are certain subtle differences in the velocities at different positions. During magnetic storms, the data within the horizontal area will show obvious differences.

[0102] A multi-station incoherent scatter radar thermospheric horizontal area wind field calculation system according to the second embodiment of the present invention includes:

[0103] An included angle calculation module configured to calculate the polarization angles of the transmitting station and the receiving stations based on the parameters of the transmitting beam and the receiving beam of the multi-station incoherent scatter radar; calculate the included angle between the transmitting beam and the receiving beam according to the relationship between the polarization angles; the parameters include the azimuth angle and the elevation angle;

[0104] A line-of-sight velocity acquisition module configured to combine the included angle and calculate the line-of-sight velocity of each station in the coordinate system centered on the scatter point according to the echo Doppler frequency shift amount, that is, the line-of-sight velocities in different directions within the same scatter volume;

[0105] A wave vector calculation module configured to connect the coordinates of the transmitting station and each receiving station, and establish a geometric transformation relationship in combination with the position of the detected scatter point, so as to obtain the backscattering wave vector of the transmitting station in the coordinate system centered on the scatter point and the scatter wave vectors of each receiving station in the coordinate system centered on the scatter point;

[0106] A vector velocity calculation module, configured to obtain a vector velocity based on the line-of-sight velocity in the coordinate system centered on the scattering point, the transmitting station backscattering wave vector in the coordinate system centered on the scattering point, and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point, in combination with the relationship between the line-of-sight velocity and the vector velocity;

[0107] A wind field acquisition module, configured to determine the diffusion velocity corresponding to the vector velocity according to the common body height; based on the diffusion velocity, calculate the thermospheric meridional wind field, and combine the distribution of different scattering points in the horizontal plane to obtain the thermospheric horizontal region wind field.

[0108] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process and related descriptions of the above-described system can refer to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0109] It should be noted that the multi-station incoherent scatter radar thermospheric horizontal region wind field calculation system provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further split into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing each module or step, and are not regarded as an improper limitation of the present invention.

[0110] An electronic device according to a third embodiment of the present invention includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein, the memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above multi-station incoherent scatter radar thermospheric horizontal region wind field calculation method.

[0111] A computer-readable storage medium according to a fourth embodiment of the present invention stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above multi-station incoherent scatter radar thermospheric horizontal region wind field calculation method.

[0112] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process and related descriptions of the above-described electronic device and computer-readable storage medium can refer to the corresponding process in the foregoing method examples, and will not be repeated here.

[0113] Those skilled in the art should be able to realize that the modules and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field. To clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in the form of electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0114] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or represent a specific order or sequence.

[0115] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, so that a process, method, article, or device / apparatus comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to these process, method, article, or device / apparatus.

[0116] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A method for calculating the thermospheric horizontal regional wind field of a multi-station incoherent scatter radar, characterized in that, The method includes: Calculating the polarization angles of the transmitting station and the receiving stations based on the parameters of the transmitting beam and the receiving beam of the multi-station incoherent scatter radar; calculating the angle between the transmitting beam and the receiving beam according to the relationship of each polarization angle; the parameters include azimuth angle and elevation angle; Combining the angle, and calculating the line-of-sight velocities of each station in the coordinate system centered on the scatter point according to the echo Doppler frequency shift amount, that is, the line-of-sight velocities in different directions within the same scattering volume; Connecting the coordinates of the transmitting station and each receiving station, and establishing a geometric transformation relationship in combination with the position of the detected scatter point, so as to obtain the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point and the scattering wave vectors of each receiving station in the coordinate system centered on the scatter point; Based on the line-of-sight velocities in the coordinate system centered on the scatter point, the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point, and the scattering wave vectors of each receiving station in the coordinate system centered on the scatter point, and combining the relationship formula between the line-of-sight velocity and the vector velocity, obtaining the vector velocity of multi-station collaborative detection in the same scattering volume; Determining the diffusion velocity corresponding to the vector velocity of multi-station collaborative detection in the same scattering volume according to the common body height; calculating the thermospheric meridional wind field based on the diffusion velocity, and combining the distribution of different scatter points in the horizontal plane to obtain the thermospheric horizontal regional wind field; If the multi-station incoherent scatter radar is one transmitting and three receiving, establishing a relationship formula between the line-of-sight velocity and the vector velocity according to the scattering wave vectors of the receiving stations: ； Among them, represents the vector velocity of triple-station collaborative detection of the same scattering volume, , , respectively represent the line-of-sight velocities of the first station, the second station, and the third station, represents a 3×3 matrix, and each row is , and ; , represent the scattered wave vectors of each receiving station in the coordinate system centered on the scattering point, that is, the scattered wave vector of the second station and the scattered wave vector of the third station in the coordinate system centered on the scattering point, represents the backscattered wave vector of the transmitting station in the coordinate system centered on the scattering point, that is, the vector between the first station and the scattering point.

2. The method for calculating the thermospheric horizontal regional wind field of the multi-station incoherent scatter radar according to claim 1, wherein Calculating the polarization angles of the transmitting station and the receiving stations, and the method is: ； Among them, and represent the polarization angles of the transmitting station and the receiving station respectively, is the angle between the horizontal direction and the electric field direction of the transmitting beam, , , represent the three components corresponding to the transmitting beam vector respectively, , , represent the three components corresponding to the receiving beam vector respectively, and represent the azimuth angle and elevation angle corresponding to the transmitting beam respectively, and represent the azimuth angle and elevation angle corresponding to the receiving beam respectively.

3. The method for calculating the thermospheric horizontal regional wind field of the multi-station incoherent scatter radar according to claim 2, wherein Calculating the angle between the transmitting beam and the receiving beam, and the method is: ； Among them, represents the included angle between the transmitting beam and the receiving beam.

4. The method for calculating the thermospheric horizontal region wind field of a multi-station incoherent scatter radar according to claim 3, wherein Combining the angle, and calculating the line-of-sight velocities of each station in the coordinate system centered on the scatter point according to the echo Doppler frequency shift amount, and the method is: ； Among them, represents the echo Doppler frequency shift amount, represents the line-of-sight velocity of each station in the coordinate system centered on the scatterer, is the wavelength.

5. The method for calculating the thermospheric horizontal region wind field of the multi-station incoherent scatter radar according to claim 1, wherein If the multi-station incoherent scatter radar is one transmitting and three receiving, and one of the stations is both a transmitting station and a receiving station, taking this station as the first station, and the other two stations are only receiving stations, which are respectively used as the second station and the third station, then the method for obtaining the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point and the scattering wave vectors of each receiving station in the coordinate system centered on the scatter point is: Performing beam coordinate transformation on each station, and combining the transformation relationship between the longitude and latitude geographic coordinate system and the geocentric coordinate system of each station and the transformation relationship between the geocentric coordinate system and the coordinate system centered on the scatter point to obtain the backward scattering wave vector of the transmitting station in the coordinate system centered on the scatter point and the scattering wave vectors of each receiving station in the coordinate system centered on the scatter point: ； ； Among them, , represent the scattered wave vectors of each receiving station in the coordinate system centered on the scattering point, that is, the scattered wave vector of the second station in the coordinate system centered on the scattering point, and the scattered wave vector of the third station in the coordinate system centered on the scattering point. represents the backscattered wave vector of the transmitting station in the coordinate system centered on the scattering point, that is, the vector between the first station and the scattering point. represents the distance between the first station and the scattering point. represents the distance between the second station and the scattering point. represents the distance between the third station and the scattering point. and represent the vectors between the second station and the scattering point, and the vectors between the third station and the scattering point.

6. The method for calculating the thermospheric horizontal regional wind field of a multi-station incoherent scatter radar according to claim 5, wherein If the multi-station incoherent scatter radar is one transmitting and three receiving, the relationship formula between the line-of-sight velocity and the vector velocity is: ； Among them, , , respectively represent the line-of-sight velocities of the first, second, and third stations, represents the vector velocity of the three-station collaborative detection of the same scattering volume.

7. The method for calculating the thermospheric horizontal regional wind field of a multi-station incoherent scatter radar according to claim 6, wherein The method for obtaining the thermospheric horizontal regional wind field is: Further calculating the wind fields in different directions within the same scattering body through the vector velocities in different directions within the same scattering body, and combining the distribution of different scatter points in the horizontal plane in the horizontal plane to obtain the thermospheric horizontal regional wind field.

8. A multi-station incoherent scatter radar thermospheric horizontal region wind field calculation system, characterized in that, The system includes: An included angle calculation module, configured to calculate the polarization angles of the transmitting station and the receiving station based on the parameters of the transmitting beam and the receiving beam of the multi-station incoherent scatter radar; and calculate the included angle between the transmitting beam and the receiving beam according to the relationship between the polarization angles; the parameters include the azimuth angle and the elevation angle. A line-of-sight velocity acquisition module, configured to combine the included angle and calculate the line-of-sight velocities of each station in the coordinate system centered on the scattering point according to the echo Doppler frequency shift amount, that is, the line-of-sight velocities in different directions within the same scattering volume. A wave vector calculation module, configured to connect the coordinates of the transmitting station and each receiving station, and establish a geometric transformation relationship in combination with the position of the detected scattering point, so as to obtain the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point. A vector velocity calculation module, configured to obtain the vector velocity of multi-station collaborative detection in the same scattering volume based on the line-of-sight velocity in the coordinate system centered on the scattering point, the backscattering wave vector of the transmitting station in the coordinate system centered on the scattering point, and the scattering wave vectors of each receiving station in the coordinate system centered on the scattering point, in combination with the relationship formula between the line-of-sight velocity and the vector velocity. A wind field acquisition module, configured to determine the diffusion velocity corresponding to the vector velocity of multi-station collaborative detection in the same scattering volume according to the co-body height; calculate the thermospheric meridional wind field based on the diffusion velocity, and combine the distribution of different scattering points in the horizontal plane to obtain the thermospheric horizontal region wind field. If the multi-station incoherent scatter radar is one transmitting and three receiving, establish a relationship formula between the line-of-sight velocity and the vector velocity according to the scattering wave vectors of the receiving stations: ； Among them, represents the vector velocity of three-station collaborative detection of the same scattering volume, , , respectively represent the line-of-sight velocities of the first station, the second station, and the third station, represents a 3×3 matrix, and each row is , and ; 、 represent the scattered wave vectors of each receiving station in the coordinate system centered on the scattering point, that is, the scattered wave vector of the second station in the coordinate system centered on the scattering point and the scattered wave vector of the third station in the coordinate system centered on the scattering point, represents the backscattered wave vector of the transmitting station in the coordinate system centered on the scattering point, that is, the vector between the first station and the scattering point.

9. An electronic device, characterized in that, Including: At least one processor; And A memory communicatively connected to at least one of the processors; wherein, The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the method for calculating the thermospheric horizontal region wind field of the multi-station incoherent scatter radar according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the method for calculating the thermospheric horizontal region wind field of the multi-station incoherent scatter radar according to any one of claims 1-7.

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