A method for extracting collision frequency in the ionospheric F region based on incoherent scatter radar

Abstract

The present application belongs to the field of signal and information processing, and specifically relates to a method for extracting the collision frequency of the ionospheric F region based on incoherent scattering radar, aiming to solve the problem of being unable to obtain the 24-hour change of the collision frequency of the ionospheric F region. The method includes: obtaining ionospheric parameters of the ionospheric F region based on incoherent scattering radar; obtaining ion vector velocity based on the ion line-of-sight velocity under multiple line-of-sight directions; determining the zero-value altitude of the diffusion velocity based on the electron density, electron temperature, ion temperature and ion mass when the diffusion velocity of ions in the ionosphere is 0; determining the target diffusion velocity at the target altitude based on the meridional wind, ion vector velocity and magnetic inclination at the zero-value altitude of the diffusion velocity; and determining the collision frequency of the ionospheric F region based on the target diffusion velocity. The present application realizes 24-hour continuous measurement of the collision frequency of the ionospheric F region.

Description

Technical Field

[0001] The present application belongs to the field of signal and information processing, and specifically relates to a method, system, device and storage medium for extracting ionospheric F-zone collision frequency based on incoherent scattering radar. Background Art

[0002] The ionosphere is the key layer in the solar-terrestrial space environment that is most closely related to human activities, and has an important impact on radio communications, satellite navigation and positioning, manned space flight, etc.

[0003] Observations show that the electron density of the ionosphere is vertically layered. Within an altitude of approximately 60 to 1000 kilometers above the Earth's surface, there are three main layers: the D layer, the E layer, and the F layer. The D layer is the bottom of the ionosphere, consisting of a layer of atmosphere with low ionization, located approximately 60 to 90 kilometers. The E layer, located approximately 90 to 140 kilometers, is relatively stable. Above the E layer, extending to hundreds or even thousands of kilometers, is the F layer, the main region of the ionosphere.

[0004] Due to the absorption of solar radiation, oxygen atoms (O) in the ionosphere are ionized into oxygen ions (O + ) is the main component of the F region of the Earth's ionosphere. + The interaction between ions and O, especially through collisions, controls the structure and dynamics of the Earth's upper atmosphere (see: Salah, JE (1993). Interim standard for the ion-neutralatomic oxygen collisionfrequency. Geophysical Research Letters, 20(15), 1543-1546. https: / / doi.org / 10.1029 / 93GL01699), including their velocity, temperature, and density. Therefore, O + The -O collision frequency is a fundamental parameter describing the interaction between ions and neutral components in the ionosphere-thermosphere system.

[0005] However, there are currently no adequate methods to directly measure O under thermal conditions in the upper atmosphere. + -O collision frequency. Many scholars have conducted O +-O collision frequency calculation (see: Pesnell, WD, Omidvar, K.,&Hoegy, WR (1993). Momentum transfer collisionfrequency of O+-O. Geophysical Research Letters, 20(13), 1343–1346. https: / / doi.org / 10.1029 / 93GL01597;Stallcop, JR, Partridge, H.,&Levin, E. (1991). Resonance charge transfer, transport cross sections, and collisionintegralsfor N+ (3P)-N (4S) and O+ (4S)-O (3P) interactions. The Journal ofchemical physics, 95(9), 6429–6439. https: / / doi.org / 10.1063 / 1.461563;Stebbings, RF, Smith, ACH,&Ehrhard, H. (1964). Charge transferbetween oxygen atoms and O+ and H+ ions. Journal of Geophysical Research, 69(11), 2349–2355. https: / / doi.org / 10.1029 / JZ069i011p02349). So far, only Stebbings et al. (1964) have directly measured the O + -O collision frequency cross section, but must be extrapolated from energies above 40 eV to below 1 eV. +The expression of the -O collision cross section has been theoretically calculated and analyzed, among which the most commonly used formula is Banks (see: Banks, P. (1966). Collision frequencies and energytransferions. Planetary and Space Science, 14(11), 1105–1122; Salah, JE (1993). Interim standard for the ion-neutral atomic oxygen collisionfrequency. Geophysical Research Letters, 20(15), 1543-1546. https: / / doi.org / 10.1029 / 93GL01699; Schunk, RW, & Walker, JCG (1973). Theoretical iondensities in the lower ionosphere. Planetary and Space Science, 21(11), 1875–1896. https: / / doi.org / 10.1016 / 0032-0633(73)90 118-9). In addition to the collision cross section, the density of oxygen atoms is also required when calculating the collision frequency, which is usually derived from an empirical model.

[0006] Of all ionospheric detection methods, incoherent scatter radar (ISR) is by far the most powerful, offering numerous advantages, including robust detection capabilities, multiple parameters (multiple field and particle components), high accuracy, fine resolution, and wide altitude coverage. The high-power phased array ISR, developed and deployed in Sanya in the low-latitude ionosphere, offers new technical advantages, including continuous observation, full airspace coverage, and rapid localized spatial scanning.

[0007] Incoherent scatter radar observations provide several ways to verify collision cross sections determined from laboratory data or quantum mechanical calculations. Whether it is the energy balance (EB) method (see: Carlson, HC,&Harper, RM(1977). An experimental estimate of the O+-O resonant charge transfer crosssection,collision frequency, and energy transfer rate. Journal of GeophysicalResearch, 82(7), 1144–1148.https: / / doi.org / 10.1029 / JA082i007p01144;Burnside,RG, Sulzer, MP,&Walker, JCG (1988). Determination of thermospherictemperatures and neutral densities at Arecibo from the ion energybalance.Journal of Geophysical Research, 93(A8), 8642–8650. https: / / doi.org / 10.1029 / JA093iA 08p08642;Nicolls, MJ, Aponte, N., González, SA, O+-O collision cross section and long-term F region O densityvariations deduced from the ionospheric energy budget.Journal of GeophysicalResearch, 101(A10), 21,769–21,784.https: / / doi.org / 10.1029 / 96J A01585;Winser,KJ, Farmer, AD, Rees, D.,&Aruliah, A. (1988). Ion-neutral dynamics in the high latitude ionosphere: First resultsfrom the INDI experiment. Journalof Atmospheric and Terrestrial Physics, 50(4), pp. 369–377.https: / / doi.org / 10.1016 / 0021-9169(88)90021-9)Specific smooth muscle mass(MB)surface(references):Buonsanto, MJ,Tung, YK,&Sipler, DP (1992). Neutral atomic oxygen density fromnighttime radar and optical windmeasurements at Millstone Hill. Journal ofGeophysical Research, 97(A6), 8673–8679. https: / / doi.org / 10.1029 / 92JA00435;Davis, CJ, Farmer, AD,&Aruliah, A. (1995). An optimized method forcalculating the O+-O collision parameter from aeronomicalmeasurements.Annals Geophysicae, 13(5), 541–550. Reddy, CA, Hoegy, WR, Pesnell, WD, Mayr, HG,&Hines, CO(1994). Accuracy of O+-O collision cross-section deduced from ionosphere-thermosphere observations.Geophysical Research Letters,21(22), 2429–2432.https: / / doi.org / 10.1029 / 94GL02494;Sipler, D. P., Hagan, M. E., Zipf, M. E.,&Biondi, M. A. (1991). Combined optical and radar wind measurements in the Fregion overMillstone Hill. Journal of Geophysical Research, 96(A12), 21,255–21,262. https: / / doi.org / 10.1029 / 91JA02371;Vickers, H., Kosch, M. J., Sutton,E., Ogawa, Y.,&La Hoz, C. (2013). Thermospheric atomic oxygen densityestimates using theEISCAT Svalbard Radar. Journal of Geophysical Research:Space Physics, 118, 1319–1330. https: / / doi.org / 10.1002 / jgra.50169;Wu, Q.,Wang, W., Roble, R. G., Hággstróm, I.,&Strømme, A. (2012). First daytimethermospheric wind observation from aballoon-borne Fabry-Perot interferometerover Kiruna (68N). Geophysical Research Letters, 39, L14104. https: / / doi.org / 10.1029 / 2012GL052533) can be used to estimate collision frequencies, primarily by correcting the theoretical collision cross section to obtain an accurate collision frequency. The EB method primarily calculates the density of neutral atomic oxygen using incoherent scatter radar (ISR) measurements. By comparing the neutral atomic oxygen density obtained by ISR with that obtained from empirical models, the collision frequency coefficient is determined, thereby obtaining an accurate collision frequency. The MB method calibrates the meridional wind measured by the ISR with that measured by a nearby Fabry-Perot interferometer (FPI). The collision frequency coefficient is then determined to obtain an accurate collision frequency.

[0008] However, most of the aforementioned studies have very limited observational data, which limits our understanding of the collision frequency coefficient. On the one hand, the MB method using FPI data is only available at night, while the EB method is mainly applicable to the daytime. Generally speaking, the EB and MB methods obtain collision frequency coefficients at different local times, and the collision frequencies obtained by these two methods cannot cover a full 24-hour period. On the other hand, both of the above methods provide an average value. However, this average value may only be a rough approximation, and the collision frequency varies within 24 hours. There is currently no method that can obtain results on the collision frequency varying over a 24-hour period. Summary of the Invention

[0009] In order to solve the above-mentioned problem in the prior art, namely, the problem that the ionospheric F region collision frequency cannot be obtained as it changes over 24 hours, the first aspect of the present application proposes a method for extracting the ionospheric F region collision frequency based on incoherent scatter radar, comprising:

[0010] Step S10, acquiring ionospheric parameters of the ionosphere F region based on the incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature, and ion line-of-sight velocity;

[0011] Step S20, obtaining ion vector velocity according to the ion line-of-sight velocity in multiple line-of-sight directions;

[0012] Step S30, when the diffusion velocity of ions in the ionosphere is zero, determining a diffusion velocity zero value height based on the electron density, electron temperature, ion temperature and ion mass;

[0013] Step S40, determining a target diffusion velocity at a target altitude based on the meridional wind at the diffusion velocity zero altitude, the ion vector velocity, and the magnetic inclination, wherein the target altitude is an altitude above the diffusion velocity zero altitude;

[0014] Step S50: determining the collision frequency of the ionospheric F region based on the target diffusion velocity.

[0015] As a preferred embodiment, determining the zero-value height of the diffusion velocity includes:

[0016] Setting the diffusion velocity in the diffusion formula to zero, and determining the zero-value height of the diffusion velocity according to the electron density, the electron temperature, the ion temperature, and the ion mass in the diffusion formula;

[0017] Wherein, the diffusion formula is:

[0018]

[0019] in, represents the diffusion rate, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, Indicates magnetic inclination I The sine value of represents the ion mass, represents the collision frequency, represents the electron density, represents the sign of the partial derivative, h represents the height, and g represents the acceleration due to gravity.

[0020] As a preferred embodiment, determining the target diffusion velocity at the target height includes:

[0021]

[0022] in, represents the target diffusion speed, represents the velocity along the magnetic field lines, The meridional wind at the zero-value height of the diffusion velocity, cos I Represents the cosine value of the magnetic inclination, wherein the velocity along the magnetic field line direction is one of the ion vector velocities.

[0023] As a preferred embodiment, the meridional wind at the zero-value height of the diffusion velocity includes:

[0024]

[0025] in, Represents the velocity along the magnetic field lines at the height of zero diffusion velocity.

[0026] As a preferred embodiment, determining the collision frequency of the ionospheric F region based on the target diffusion velocity includes:

[0027]

[0028] in, represents the collision frequency, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, Indicates magnetic inclination I The sine value of represents the ion mass, represents the target diffusion speed, represents the electron density, represents the symbol of partial derivative, represents the target height, and g represents the acceleration due to gravity.

[0029] As a preferred embodiment, obtaining ionospheric parameters of the ionosphere F region based on incoherent scatter radar includes:

[0030] Acquiring a scattered signal generated by the incoherent scattering radar transmitting electromagnetic waves to the ionosphere;

[0031] Fitting the theoretical power spectrum and the measured power spectrum of the scattered signal at different altitudes;

[0032] The ionospheric parameter is obtained when a fitting error between the theoretical power spectrum and the measured power spectrum is minimized.

[0033] As a preferred embodiment, obtaining the ion vector velocity according to the ion line-of-sight velocity in multiple line-of-sight directions includes:

[0034] According to the relationship between the ion line-of-sight velocity and the vector velocity in the geomagnetic coordinate system, the ion line-of-sight velocities in different directions are combined to perform least square fitting to obtain the ion vector velocity.

[0035] In a second aspect of the present application, a system for extracting ionospheric F-region collision frequencies based on incoherent scatter radar is proposed, comprising:

[0036] An ionospheric parameter acquisition module is used to acquire ionospheric parameters of the ionosphere F region based on an incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature, and ion line-of-sight velocity;

[0037] an ion vector velocity acquisition module, configured to acquire an ion vector velocity according to the ion line-of-sight velocity in a plurality of line-of-sight directions;

[0038] a diffusion velocity zero value height determination module, configured to determine the diffusion velocity zero value height based on the electron density, electron temperature, ion temperature and ion mass when the diffusion velocity of ions in the ionosphere is zero;

[0039] a target diffusion velocity determination module, configured to determine a target diffusion velocity at a target altitude based on the meridional wind at the diffusion velocity zero altitude, the ion vector velocity, and the magnetic inclination, wherein the target altitude is an altitude above the diffusion velocity zero altitude;

[0040] The collision frequency determination module is used to determine the collision frequency of the ionospheric F region based on the target diffusion speed.

[0041] In a third aspect of the present application, an electronic device is provided, comprising:

[0042] at least one processor; and

[0043] a memory communicatively connected to at least one of the processors; wherein,

[0044] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned method for extracting the ionospheric F-region collision frequency based on incoherent scatter radar.

[0045] In a fourth aspect of the present application, a computer-readable storage medium is proposed, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned method for extracting the ionospheric F-zone collision frequency based on incoherent scatter radar.

[0046] Beneficial effects of this application:

[0047] This application realizes 24-hour continuous measurement of the collision frequency in the ionospheric F region.

[0048] (1) This application uses the Sanya incoherent scattering radar to obtain ionospheric parameters in the F region of the ionosphere, and further calculates the target diffusion velocity at the target altitude through the diffusion velocity zero value altitude to achieve the measurement of collision frequency. Since each ionospheric parameter can be sampled continuously for 24 hours, the method of this application can obtain accurate 24-hour collision frequency results and changes without relying on other observation means.

[0049] (2) The coupling between the thermosphere and the ionosphere is mainly through the collision interaction between particles. The collision frequency is a very important parameter, but it is also a very difficult parameter to measure. This paper uses the Sanya incoherent scattering radar to measure the precise collision frequency, which can further analyze the interaction and coupling mechanism between the thermosphere and the ionosphere.

[0050] (3) As the Sanya Incoherent Scatter Radar collects more data in the future, it will be possible to analyze the collision frequency under different solar activities in different seasons. Based on the collision frequency measurement results, we can further refine the collision frequency in the existing theoretical model, thereby optimizing the existing theoretical model and further improving the accuracy of the theoretical model. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0052] Figure 1 This is a flow chart of a method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to the first embodiment of the present application;

[0053] Figure 2 This is a time series diagram of the meridional wind speed corresponding to the zero-value height of the diffusion velocity provided in the first embodiment of the present application;

[0054] Figure 3 This is a diffusion velocity timing diagram of a target height provided by the first embodiment of the present application;

[0055] Figure 4 This is a timing diagram of the collision frequency coefficient within a target altitude range of 10 km provided by the first embodiment of the present application;

[0056] Figure 5 This is a collision frequency coefficient comparison chart provided by the first embodiment of the present application;

[0057] Figure 6 This is a system block diagram of a system for extracting ionospheric F-region collision frequency based on incoherent scatter radar, provided in the second embodiment of the present application;

[0058] Figure 7 It is a structural diagram of a computer system of a server for implementing the method, system, and device embodiments of the present application. DETAILED DESCRIPTION

[0059] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.

[0060] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0061] The coupling between the ionosphere and thermosphere is largely controlled by the collisions between ions and neutral particles. In the ionosphere and thermosphere above 200 km, O and O + is the main component, therefore, O +The collision frequency of O- plays a crucial role in the momentum and energy transfer between the thermosphere and the ionosphere. For decades, researchers have mainly studied O- using energy balance and momentum balance methods, using observational data from incoherent scattering radar. + -O collision frequency. However, these two methods are limited to daytime and nighttime respectively, and the energy balance method needs to rely on the results of the model, while the momentum balance method needs to rely on FPI data. To address this limitation, the present application provides a method for extracting the ionospheric F region collision frequency based on incoherent scatter radar. This method uses the newly built Sanya incoherent scatter radar to calculate the ionospheric F region collision frequency, which can obtain a 24-hour collision frequency without relying on other observation data.

[0062] In order to more clearly explain the method of extracting the ionospheric F region collision frequency based on the incoherent scattering radar in this application, the following is combined with Figure 1 Each step in the embodiments of the present application is described in detail.

[0063] The method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to the first embodiment of the present application includes steps S10 to S50, each of which is described in detail as follows:

[0064] Step S10: Acquire ionospheric parameters of the ionosphere F region based on the incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature, and ion line-of-sight velocity.

[0065] It should be noted that electromagnetic waves of a certain frequency will produce Thomson scattering after entering the ionosphere. The scattered signal contains information such as the temperature, density, and drift velocity of the plasma.

[0066] Optionally, the incoherent scattering radar can generate scattered signals by emitting electromagnetic waves to the ionosphere, and can measure various parameters of the ionosphere by receiving and processing the scattered signals.

[0067] In an embodiment of the present application, a scattered signal generated by an incoherent scattering radar transmitting electromagnetic waves to the ionosphere is obtained; a theoretical power spectrum and a measured power spectrum of the scattered signal are fitted at different altitudes; and ionospheric parameters are obtained when the fitting error between the theoretical power spectrum and the measured power spectrum is minimized.

[0068] Among them, at any altitude in the ionosphere F region, the theoretical power spectrum and the measured power spectrum of the scattered signal are fitted by least squares fitting, and the fitted electron density, electron temperature, ion temperature and ion line-of-sight velocity are output as the ionosphere parameters at that arbitrary altitude.

[0069] Step S20 , obtaining ion vector velocity according to the ion line-of-sight velocity in multiple line-of-sight directions.

[0070] It should be noted that when obtaining the ion vector velocity, it is necessary to assume that the velocity field is spatially uniform, that is, to assume that the vector velocity is constant within a certain spatial range. The accurate ion vector velocity can be obtained by measuring the ion line-of-sight velocities in three directions.

[0071] Optionally, based on the relationship between the ion line-of-sight velocity and the ion vector velocity in the geomagnetic coordinate system, the ion line-of-sight velocities in different directions are combined to perform least square fitting to obtain the ion vector velocity.

[0072] In the embodiment of the present application, based on the fast beam switching capability of the Sanya incoherent scattering radar, more beams can be used to perform least squares fitting within a certain spatial range to obtain the ion vector velocity.

[0073] In this embodiment, the process of obtaining the ion vector velocity is a prior art, and reference may be made to the specific implementation of patent: CN202310627691.7, which will not be repeated here.

[0074] Step S30 : When the diffusion velocity of ions in the ionosphere is zero, the zero-value height of the diffusion velocity is determined based on the electron density, the electron temperature, the ion temperature and the ion mass.

[0075] Alternatively, the diffusion velocity of ions in the ionospheric F region can be determined according to the diffusion velocity formula (see Chen, GM, Xu, J., Wang, W., Lei, J., & Zhang, SR (2014). The responses of ionospheric topside diffusivefluxes to two geomagnetic storms in October 2002. Journal ofGeophysicalResearch: Space Physics, 119(8), 6806–6820. https: / / doi.org / 10.1002 / 2014ja020013). The diffusion velocity formula is as follows:

[0076]

[0077] in, represents the diffusion rate, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, Indicates magnetic inclination I The sine value of represents the ion mass, represents the collision frequency, represents the electron density, represents the sign of the partial derivative, h represents the height, and g represents the acceleration due to gravity.

[0078] Among them, the main component of the ion in the F region of the ionosphere is oxygen ion. Therefore, the ion mass in the embodiment of the present application refers to the mass of oxygen ion, which is 16×amu. The atomic mass amu=1.6605402×10 -27 kg.

[0079] It should be noted that the ionosphere is a plasma layer, which is affected by electromagnetic forces in addition to gravity and collisions. Since it is an unknown quantity, the exact diffusion rate cannot be directly obtained.

[0080] Optionally, to eliminate the impact of collision frequency, the diffusion velocity in the diffusion formula is set to zero. The zero-value altitude of the diffusion velocity is determined based on the electron density, electron temperature, ion temperature, and ion mass in the diffusion formula. In other words, the result within the square brackets in the diffusion formula needs to be set to 0. The zero-value altitude of the diffusion velocity can be calculated based on the ionospheric parameters obtained by the incoherent scatter radar.

[0081] Step S40 , determining a target diffusion velocity at a target altitude based on the meridional wind, ion vector velocity, and magnetic inclination at the diffusion velocity zero altitude, wherein the target altitude is an altitude above the diffusion velocity zero altitude.

[0082] Alternatively, when the diffusion velocity approaches 0, the meridional wind mainly depends on the velocity along the magnetic field lines and the magnetic inclination.

[0083] As an example, the meridional wind at the zero-value altitude of the diffusion velocity can be determined by the following formula:

[0084]

[0085] in, The meridional wind at the zero-value height of the diffusion velocity, cos I represents the cosine value of the magnetic inclination, Represents the velocity along the magnetic field lines at the height of zero diffusion velocity.

[0086] It should be noted that the velocity along the direction of magnetic field lines is one of the ion vector velocities.

[0087] According to research (see: Rishbeth, H.,&Garriott, OK (1969),Introduction to Ionospheric Physics, Academic Press, New York.;Hedin, AE,Spencer, NW, Biondi, MA, et al.(1991). Revised Global Model ofThermosphere Winds using satellite and Ground-based observations. Journal ofGeophysical Research Atmospheres, 1991,96(A5). https: / / doi.org / 10.102 9 / 91JA00251), the height gradient of the meridional wind in high altitude areas (i.e., the F layer and above) can be ignored (see: Lei, J., Wang, W., Burns, AG, Solomon, SC, Richmond, AD,Wiltberger, M., Goncharenko, LP, Coster, A.,&Reinisch, BW (2008).Observations and simulations of the The altitude where the diffusion velocity is zero is usually always higher than the ionospheric peak altitude. Therefore, the meridional wind hardly changes at or above the altitude where the diffusion velocity is zero. In other words, the meridional wind at the altitude where the diffusion velocity is zero can be used to represent the meridional wind at altitudes above the diffusion velocity (i.e., the target altitude).

[0088] Furthermore, the target diffusion speed at the target height can be obtained according to the following formula:

[0089]

[0090] in, represents the target diffusion speed, Indicates the velocity along the direction of magnetic field lines.

[0091] In the embodiment of the present application, the meridional wind at the zero-value height of the diffusion velocity is Represents the meridional wind at the target altitude.

[0092] Step S50: determining the collision frequency of the ionospheric F region based on the target diffusion velocity.

[0093] The collision frequency can be calculated using the following formula:

[0094]

[0095] in, represents the collision frequency, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, Indicates magnetic inclination I The sine value of represents the ion mass, represents the target diffusion speed, represents the electron density, represents the symbol of partial derivative, represents the target height, and g represents the acceleration due to gravity.

[0096] In the embodiment of the present application, based on the target diffusion velocity obtained in the above steps, the collision frequency of the ionospheric F region can be further calculated.

[0097] In order to verify the effectiveness of the method described in this application, the examples of this application provide the following verification experiments.

[0098] From November 2023 to October 2024, the Sanya incoherent scattering radar conducted a year-long continuous experiment using a 480µs long pulse waveform. The Sanya incoherent scatter radar is located in Sanya and operates in the UHF band of 430-450 MHz with a peak power of more than 4MW (see Yue, X., Wan, W., Ning, B., Jin, L., Ding, F., Zhao,B., et al. (2022). Development of the Sanya incoherent scatter radarandpreliminary results. Journal of Geophysical Research: Space Physics, 127(8), e2022JA030451. https: / / doi.org / 10.1029 / 2 022JA030451;Yue, X., Ning, B.,Jin, L.,&Wang, C. (2024). A tristatic phased array radar system in China.Nature Astronomy, 8(5), 673-673.http: / / doi.org / 10.1038 / s41550-024-0227 4-z).

[0099] See also Figure 2-Figure 4 The observation data of Sanya incoherent scatter radar on November 24, 2023 are shown in Figure 2, where: Figure 2 is the time series diagram of the meridional wind speed corresponding to the zero-value height of the diffusion velocity, Figure 3 is the diffusion velocity time series diagram at target height, Figure 4 This is a time series diagram of the collision frequency coefficient within a target altitude range of 10 km. It can be seen that the collision frequency changes gradually over time.

[0100] It should be noted that the collision frequency can be obtained through the collision frequency coefficient. The collision frequency coefficient is used as the experimental result data in order to compare with the results obtained by the momentum balance method.

[0101] Furthermore, the momentum balance method used in previous literature was used for verification. The collision frequency coefficient at night (labeled as FPI-ISR) was obtained using the momentum balance method based on the FPI data and Sanya incoherent scatter radar at the same location. Figure 5The collision frequency coefficient comparison chart from November 2023 to January 2024 is compared with the collision frequency coefficient timing chart (marked as ISR) obtained in the embodiment of the present application. It can be seen from the figure that the two are well consistent, which proves the effectiveness of the method described in the present application.

[0102] Previous studies usually only obtained collision frequencies during the day or only at night. This application uses the Sanya incoherent scattering radar and a new method to provide accurate 24-hour collision frequency results and changes, and does not rely on other observation data.

[0103] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of this application.

[0104] See also Figure 6 The system for extracting ionospheric F-zone collision frequency based on incoherent scattering radar in the second embodiment of the present application includes: an ionospheric parameter acquisition module 100, an ion vector velocity acquisition module 200, a diffusion velocity zero value height determination module 300, a target diffusion velocity determination module 400 and a collision frequency determination module 500.

[0105] The ionospheric parameter acquisition module 100 is used to acquire ionospheric parameters of the ionosphere F region based on incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature and ion line-of-sight velocity;

[0106] The ion vector velocity acquisition module 200 is used to obtain the ion vector velocity according to the ion line-of-sight velocities in multiple line-of-sight directions;

[0107] A diffusion velocity zero value height determination module 300 is configured to determine a diffusion velocity zero value height based on electron density, electron temperature, ion temperature, and ion mass when the diffusion velocity of ions in the ionosphere is zero.

[0108] a target diffusion velocity determination module 400 for determining a target diffusion velocity at a target altitude based on the meridional wind, the ion vector velocity, and the magnetic inclination at the diffusion velocity zero altitude, wherein the target altitude is an altitude above the diffusion velocity zero altitude;

[0109] The collision frequency determination module 500 is used to determine the collision frequency of the ionospheric F region based on the target diffusion velocity.

[0110] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the system described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0111] It should be noted that the system for extracting the ionospheric F-zone collision frequency based on incoherent scattering radar provided in the above embodiment is only illustrated by the division of the above-mentioned functional modules. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present application can be decomposed or combined. For example, the modules of the above embodiment can be combined into one module, or further divided 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 application are only for distinguishing the modules or steps and are not regarded as improper limitations on the present application.

[0112] An electronic device according to a third embodiment of the present application includes:

[0113] at least one processor; and

[0114] a memory communicatively connected to at least one of the processors; wherein,

[0115] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned method for extracting the ionospheric F-region collision frequency based on incoherent scatter radar.

[0116] A computer-readable storage medium according to a fourth embodiment of the present application stores computer instructions, which are used to be executed by the computer to implement the above-mentioned method for extracting ionospheric F-region collision frequency based on incoherent scatter radar.

[0117] A computer program product according to a fifth embodiment of the present application, when running on an electronic device, enables the electronic device to execute the above-mentioned method for extracting ionospheric F-region collision frequency based on incoherent scatter radar.

[0118] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes and related instructions of the electronic device, computer-readable storage medium, and computer program product described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0119] Those skilled in the art should be aware that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0120] Reference below Figure 7 , which shows a structural diagram of a computer system of a server for implementing the method, system, and device embodiments of the present application. Figure 7 The server shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0121] like Figure 7 As shown, the computer system includes a central processing unit (CPU) 701, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 702 or the program loaded from the storage part 708 into the random access memory (RAM) 703. Various programs and data required for system operation are also stored in the RAM 703. The CPU 701, ROM 702 and RAM 703 are connected to each other via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0122] The following components are connected to the I / O interface 705: an input section 706 including a keyboard, a mouse, and the like; an output section 707 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 708 including a hard disk and the like; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, and the like, is installed in the drive 710 as needed so that a computer program read therefrom can be installed into the storage section 708 as needed.

[0123] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 709, and / or installed from the removable medium 711. When the computer program is executed by the central processing unit (CPU) 701, the above-mentioned functions defined in the method of the present application are executed. It should be noted that the computer-readable medium mentioned above in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code embodied on a computer-readable medium may be transmitted using any suitable medium, including, but not limited to, wireless, wire, optical cable, RF, etc., or any suitable combination thereof.

[0124] Computer program code for performing the operations of the present application may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0125] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0126] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0127] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0128] Thus far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for extracting ionospheric F-region collision frequency based on incoherent scatter radar, characterized in that: include: Step S10, acquiring ionospheric parameters of the ionosphere F region based on the incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature, and ion line-of-sight velocity; Step S20, obtaining ion vector velocity according to the ion line-of-sight velocity in multiple line-of-sight directions; Step S30, when the diffusion velocity of ions in the ionosphere is zero, determining a diffusion velocity zero value height based on the electron density, electron temperature, ion temperature and ion mass; Step S40, determining a target diffusion velocity at a target altitude based on the meridional wind at the diffusion velocity zero altitude, the ion vector velocity, and the magnetic inclination, wherein the target altitude is an altitude above the diffusion velocity zero altitude; Step S50, determining the collision frequency of the ionospheric F region based on the target diffusion velocity; Wherein, determining the target diffusion speed at the target height includes: ； in, represents the target diffusion speed, represents the velocity along the magnetic field lines, represents the meridional wind at the zero-value height of the diffusion velocity, cosI represents the cosine value of the magnetic inclination, wherein the velocity along the magnetic field line direction is one of the ion vector velocities; The meridional wind at the zero-value height of the diffusion velocity includes: ； in, It represents the speed of ions along the magnetic field lines at the zero-value height of diffusion velocity.

2. The method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to claim 1, characterized in that: Determining the zero-value height of the diffusion velocity includes: Setting the diffusion velocity in the diffusion formula to zero, and determining the zero-value height of the diffusion velocity according to the electron density, the electron temperature, the ion temperature, and the ion mass in the diffusion formula; Wherein, the diffusion formula is: ； in, represents the diffusion velocity, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, represents the sine value of the magnetic inclination I, represents the ion mass, represents the collision frequency, represents the electron density, represents the sign of the partial derivative, h represents the height, and g represents the acceleration due to gravity.

3. The method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to claim 1, characterized in that: The determining of the collision frequency of the ionospheric F region based on the target diffusion velocity includes: ； in, represents the collision frequency, k represents the Boltzmann constant, represents the ion temperature, represents the electron temperature, represents the sine value of the magnetic inclination I, represents the ion mass, represents the target diffusion speed, represents the electron density, represents the symbol of partial derivative, represents the target height, and g represents the acceleration due to gravity.

4. The method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to claim 1, characterized in that: The method of obtaining ionospheric parameters of the ionosphere F region based on the incoherent scatter radar includes: Acquiring a scattered signal generated by the incoherent scattering radar transmitting electromagnetic waves to the ionosphere; Fitting the theoretical power spectrum and the measured power spectrum of the scattered signal at different altitudes; The ionospheric parameter is obtained when a fitting error between the theoretical power spectrum and the measured power spectrum is minimized.

5. The method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to claim 1, characterized in that: The obtaining of ion vector velocity according to the ion line-of-sight velocity in multiple line-of-sight directions includes: According to the relationship between the ion line-of-sight velocity and the ion vector velocity in the geomagnetic coordinate system, the ion line-of-sight velocities in different directions are combined to perform least square fitting to obtain the ion vector velocity.

6. A system for extracting ionospheric F-region collision frequency based on incoherent scatter radar, characterized in that: include: An ionospheric parameter acquisition module is used to acquire ionospheric parameters of the ionosphere F region based on an incoherent scatter radar, wherein the ionospheric parameters include electron density, electron temperature, ion temperature, and ion line-of-sight velocity; an ion vector velocity acquisition module, configured to acquire an ion vector velocity according to the ion line-of-sight velocity in a plurality of line-of-sight directions; a diffusion velocity zero value height determination module, configured to determine the diffusion velocity zero value height based on the electron density, electron temperature, ion temperature and ion mass when the diffusion velocity of ions in the ionosphere is zero; a target diffusion velocity determination module, configured to determine a target diffusion velocity at a target altitude based on the meridional wind at the diffusion velocity zero altitude, the ion vector velocity, and the magnetic inclination, wherein the target altitude is an altitude above the diffusion velocity zero altitude; a collision frequency determination module, configured to determine the collision frequency of the ionospheric F region based on the target diffusion velocity; Wherein, determining the target diffusion speed at the target height includes: ； in, represents the target diffusion speed, represents the velocity along the magnetic field lines, represents the meridional wind at the zero-value height of the diffusion velocity, cosI represents the cosine value of the magnetic inclination, wherein the velocity along the magnetic field line direction is one of the ion vector velocities; The meridional wind at the zero-value height of the diffusion velocity includes: ； in, Represents the velocity along the magnetic field lines at the height of zero diffusion velocity.

7. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the method for extracting ionospheric F-region collision frequency based on incoherent scatter radar according to any one of claims 1 to 5.

8. 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 extracting ionospheric F-region collision frequency based on incoherent scatter radar according to any one of claims 1 to 5.

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