A method for detecting horizontal wind vector profiles using dual satellite companion flight wind measurement

Abstract

The present application relates to a method for detecting horizontal wind vector profiles of dual-satellite companion flight wind measurement, including: obtaining a first direction velocity vector, namely, a forward radial wind speed; obtaining a second direction velocity vector, namely, a backward radial wind speed; determining a forward laser azimuth and a forward laser altitude angle according to the first direction velocity vector, and determining a backward laser azimuth and a backward laser altitude angle according to the second direction velocity vector; performing horizontal wind vector inversion according to the forward radial wind speed, the forward laser azimuth, the forward laser altitude angle, the backward radial wind speed, the backward laser azimuth and the backward laser altitude angle to obtain a high-precision horizontal wind vector profile. The scheme of the present invention can realize the detection of forward and backward radial wind speeds at approximately the same time and in the same place, significantly reduce the distance between the forward and backward laser observation positions, and improve the inversion accuracy of the horizontal wind vector profile; by real-time solving the azimuth and altitude angles of the laser beam in the local coordinate system, the inversion accuracy of the horizontal wind vector profile is improved.

Description

Technical Field

[0001] The present application relates to the field of space-based coherent laser radar detection technology, and in particular to a method for detecting horizontal wind vector profiles by using dual satellite companion flight to measure wind. Background Art

[0002] At present, wind profile detection is still the most challenging and important demand in global meteorological analysis and research. Wind profile observation data is essential for improving the quality of global three-dimensional wind field analysis data; it is crucial for understanding atmospheric dynamic processes, including the global transport of energy, water, aerosols and chemical substances. The detection of horizontal wind vector profiles in the global boundary layer will also provide observational data support for the study of the mechanisms of global carbon cycle and water cycle processes, which are in urgent need of breakthroughs under the influence of global warming and international energy transformation. Wind profile observation data is essential for analyzing and studying the distribution of carbon sources and sinks in the global carbon cycle, and wind profile observation data can be widely used in many fields of climate change research, climate prediction and weather forecast research.

[0003] On August 22, 2018, the European Space Agency successfully launched the Aeolus satellite, realizing the first space-based observation of global wind profiles. However, the satellite can only detect the horizontal projection component profile of the laser radial wind speed, and cannot obtain the actual atmospheric horizontal wind vector profile. Therefore, space-based horizontal wind vector profile detection is still a gap that urgently needs to be filled in the global satellite detection system.

[0004] The related technologies have the following problems: (1) Single-satellite remote sensing wind vector cannot achieve simultaneous and local detection of radial wind speeds in the front and rear directions. Non-simultaneous and local observations not only affect the inversion accuracy of the horizontal wind vector, but also restrict the amount of observation data of the satellite remote sensing wind profile that can be obtained along the track. (2) When the single-satellite solution inverts the wind vector, it is assumed that the azimuth and altitude angles of the laser pointing are fixed, ignoring the technical problem of laser pointing deviation caused by the curvature of the earth and the height difference of the terrain; the inaccurate use of the azimuth and altitude angles of the laser beam will affect the inversion accuracy of the wind vector profile. Therefore, obtaining accurate laser azimuth and altitude angles is of great significance to improving the inversion accuracy of the wind vector profile. Summary of the invention

[0005] In order to overcome the problems existing in the related art at least to a certain extent, the present application provides a method for detecting horizontal wind vector profiles in dual-satellite companion flight wind measurement.

[0006] According to a first aspect of an embodiment of the present application, a method for detecting a horizontal wind vector profile by using a dual-satellite companion flight to measure wind speed is provided, comprising:

[0007] Acquire a first direction velocity vector, where the first direction velocity vector is a velocity component in the direction of the forward laser beam measured by the first satellite, that is, a forward radial wind speed;

[0008] Acquire a second direction velocity vector, where the second direction velocity vector is a velocity component in the direction of a backward laser beam measured by a second satellite, that is, a backward radial wind speed; wherein the first satellite and the second satellite are companion satellites;

[0009] Determine a forward laser azimuth and a forward laser altitude angle in a local coordinate system according to the first direction velocity vector, and determine a backward laser azimuth and a backward laser altitude angle in the same local coordinate system according to the second direction velocity vector;

[0010] The horizontal wind vector profile is obtained by performing horizontal wind vector inversion based on the forward radial wind speed, forward laser azimuth, forward laser altitude, backward radial wind speed, backward laser azimuth and backward laser altitude.

[0011] Further, the laser beams of the first satellite and the second satellite are pointed at the same nadir angle in the satellite coordinate system;

[0012] The observation direction of the first satellite is orthogonal to the horizontal projection of the observation direction of the second satellite;

[0013] The true anomaly difference between the first satellite and the second satellite is equal to the angle corresponding to the on-orbit flight time difference between the two satellites;

[0014] The right ascension difference of the ascending node of the first satellite and the second satellite satisfies: Δλ / ω e =Δγ a / ω s ; where Δλ is the right ascension difference of the ascending node between orbital planes, ω e is the angular velocity of the Earth's rotation, Δγ a is the mean anomaly angle difference, ω s is the satellite’s angular velocity in orbit.

[0015] Further, determining the forward laser azimuth angle and the forward laser altitude angle in the local coordinate system according to the first direction velocity vector includes:

[0016] A local northeast-upward coordinate system is established with the observation position of the first direction velocity vector on the large balloon table as the center;

[0017] Convert the coordinates of the first satellite in the Earth-centered Earth-fixed coordinate system to the coordinates of the local northeast-upper coordinate system;

[0018] According to the first direction vector after the coordinate system is converted, the forward laser azimuth and the forward laser altitude angle in the local northeast upper coordinate system are calculated.

[0019] Further, determining the backward laser azimuth angle and the backward laser altitude angle in the same local coordinate system according to the second direction velocity vector includes:

[0020] Convert the coordinates of the second satellite in the Earth-centered Earth-fixed coordinate system to the coordinates of the local northeast-upper coordinate system;

[0021] The coordinates of the observation position of the second satellite in the large balloon table in the earth-centered earth-fixed coordinate system are converted into coordinates in the local northeast upper coordinate system to obtain the second direction vector of the backward radial wind speed in the local northeast upper coordinate system;

[0022] According to the second direction vector after the coordinate system is converted, the backward laser azimuth and the backward laser altitude angle in the local northeast upper coordinate system are calculated.

[0023] Further, the calculation of the forward / backward laser azimuth angle and the forward / backward laser altitude angle includes:

[0024] The first / second direction vector in the local northeast coordinate system is obtained as The corresponding forward / backward laser azimuth is The corresponding forward / backward laser elevation angle is

[0025] Further, the horizontal wind vector inversion is performed according to the forward radial wind speed, the forward laser azimuth, the forward laser altitude angle, the backward radial wind speed, the backward laser azimuth and the backward laser altitude angle, including:

[0026] Determine the expression equation of the forward radial wind speed according to the forward laser azimuth angle and the forward laser altitude angle;

[0027] Determine the expression equation of the backward radial wind speed according to the backward laser azimuth angle and the backward laser altitude angle;

[0028] The assumptions are as follows: the forward and backward lasers are within the observation range of the large balloon table, the atmospheric wind field is uniformly distributed and the vertical average wind speed is zero;

[0029] The expression equations of the forward radial wind speed and the backward radial wind speed are solved according to the assumed conditions.

[0030] Furthermore, let u, v and w represent the wind speed components in the local east, north and up directions respectively, then the expression equation of the forward radial wind speed is:

[0031]

[0032] Among them, θ for is the forward laser azimuth, is the forward laser elevation angle, the forward radial wind speed is the measurement data of the first satellite;

[0033] The expression equation of the backward radial wind speed is:

[0034]

[0035] Among them, θ aft is the backward laser azimuth, is the backward laser elevation angle, and the backward radial wind speed is the measurement data of the second satellite.

[0036] Furthermore, the expression equation of the forward radial wind speed and the expression equation of the backward radial wind speed are solved according to the assumptions to obtain the horizontal wind vector include:

[0037] According to the assumptions:

[0038] make Then we have:

[0039]

[0040]

[0041] Further, obtaining the horizontal wind vector profile includes:

[0042] The horizontal wind vector profile can be constructed based on the horizontal wind vector inversion results of the large balloon table with different radii.

[0043] According to a second aspect of an embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the operating steps of the method described in any one of the above embodiments are implemented.

[0044] The technical solution provided by the embodiments of the present application has the following beneficial effects:

[0045] The dual-satellite companion flight wind measurement scheme proposed in the present invention can realize the approximately simultaneous and co-location detection of forward and backward radial wind speeds, significantly shorten the distance between the forward and backward laser observation positions, and solve the problem that the existing single-satellite scheme cannot simultaneously and co-locate the forward and backward radial wind speeds, which is beneficial to improving the detection accuracy of the space-based remote sensing horizontal wind vector profile; at the same time, fixed constant values ​​are no longer used to approximate the azimuth and altitude angles, which reduces the laser pointing deviation caused by the earth's curvature and the difference in terrain height, and further improves the inversion accuracy of the horizontal wind vector profile.

[0046] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0048] Figure 1 The present invention is a flow chart of a method for detecting horizontal wind vector profiles by using dual-satellite companion flight to measure wind according to an exemplary embodiment.

[0049] Figure 2 It is a schematic diagram of the horizontal projection principle of the wind vector measured by the double-satellite companion flight of the present invention.

[0050] Figure 3 It is the latitude difference distribution map of the observation positions of the forward and backward lasers on the surface of the big balloon.

[0051] Figure 4 It is the distribution map of the longitude difference of the observation positions of the forward and backward lasers on the surface of the big balloon.

[0052] Figure 5 It is the distance distribution diagram between the observation positions of the forward and backward lasers on the surface of the large balloon.

[0053] Figure 6 It is the distribution map of the forward and backward laser azimuth angle differences in the local Northeast Up (ENU) coordinate system.

[0054] Figure 7 It is the forward and backward laser elevation angle distribution map in the local Northeast Up (ENU) coordinate system. DETAILED DESCRIPTION

[0055] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of methods consistent with some aspects of the present application as detailed in the appended claims.

[0056] In order to more clearly illustrate the technical solution of the present application, the wind vector profile is first briefly introduced.

[0057] Space-based wind vector profile observation data is essential for improving the quality of global three-dimensional wind field analysis data; it is crucial for understanding atmospheric dynamic processes, including the global transport of energy, water, aerosols, and chemical substances. Wind profile observation data is essential for analyzing and studying the distribution of carbon sources and sinks in the global carbon cycle, and wind profile observation data can be widely used in many fields of climate change research, climate prediction, and weather forecast research.

[0058] In response to the demand for global (land and ocean) atmospheric boundary layer horizontal wind vector profiles and the shortcomings of existing detection technologies, the present invention innovatively proposes to use a dual-satellite companion flight method to remotely sense the radial wind speed in the atmospheric boundary layer, and proposes a local high-precision horizontal wind vector profile inversion method, ultimately forming an active remote sensing detection method for the boundary layer horizontal wind vector profile based on dual-satellite companion flight.

[0059] Figure 1 The present invention is a flow chart showing a method for detecting horizontal wind vector profiles by using dual satellite companion flight wind measurement according to an exemplary embodiment. The method may include the following steps:

[0060] Step S1: obtaining a first direction velocity vector, where the first direction velocity vector is a velocity component in a forward laser beam direction measured by a first satellite, that is, a forward radial wind speed;

[0061] Step S2: obtaining a second direction velocity vector, where the second direction velocity vector is a velocity component in the direction of the backward laser beam measured by a second satellite, that is, a backward radial wind speed; wherein the first satellite and the second satellite are companion satellites;

[0062] Step S3: determining a forward laser azimuth and a forward laser altitude angle in a local coordinate system according to the first direction velocity vector, and determining a backward laser azimuth and a backward laser altitude angle in the same local coordinate system according to the second direction velocity vector;

[0063] Step S4: Perform horizontal wind vector inversion according to the forward radial wind speed, the forward laser azimuth, the forward laser altitude angle, the backward radial wind speed, the backward laser azimuth and the backward laser altitude angle to obtain a horizontal wind vector profile.

[0064] The dual-satellite companion flight wind measurement scheme proposed in the present invention can realize the approximately simultaneous and co-location detection of forward and backward radial wind speeds, significantly shorten the distance between forward and backward laser observation positions, and solve the problem that the existing single-satellite scheme cannot detect the forward and backward radial wind speeds simultaneously and co-location, which is beneficial to improving the detection accuracy of the space-based remote sensing horizontal wind vector profile; at the same time, fixed constant values ​​are no longer used to approximate the azimuth and altitude angles, which helps to reduce the laser pointing deviation caused by the earth's curvature and terrain height differences, and further improve the inversion accuracy of the horizontal wind vector profile.

[0065] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0066] The solution of this application is further explained below in combination with specific application scenarios.

[0067] In order to achieve global observation, the companion satellites designed in the present invention adopt a sun-synchronous orbit. In order to enable the companion satellites (the first satellite and the second satellite) to observe at the same time and place as much as possible, the design of the two satellites needs to meet the following conditions: (1) The nadir angle of the laser beams of the two satellites in the satellite coordinate system is designed to be the same angle; in some embodiments, the value can be between 25 degrees and 50 degrees, which helps to obtain a better horizontal wind speed component. (2) To ensure the reliability of the horizontal wind vector inversion, it is necessary to ensure that the observation direction of satellite A (the first satellite) is orthogonal to the horizontal projection of the observation direction of satellite B (the second satellite); in some embodiments, the azimuth angle of the observation direction of satellite A can be designed to be 45 degrees, and the azimuth angle of the observation direction of satellite B is 135 degrees. (3) The true anomaly difference of the two satellites is equal to the angle corresponding to the difference in the in-orbit flight time between the two satellites. (4) To ensure that satellite A and satellite B have the same ground track, it is necessary to ensure that the right ascension difference of the ascending node of the two satellites satisfies the following relationship:

[0068] Δλ / ω e =Δγ a / ω s ;

[0069] Among them, Δλ is the right ascension difference of the ascending node between the orbital planes, ω e is the angular velocity of the Earth's rotation, Δγ a is the mean anomaly angle difference, ω s is the satellite’s angular velocity in orbit.

[0070] The present invention proposes a new space-based horizontal wind vector profile inversion algorithm, which establishes a local northeast-upper (ENU) coordinate system with the forward observation position coordinate as the center, and calculates the direction vector of the forward / backward laser beam in the ENU coordinate system. Calculate the local forward laser azimuth θ for, forward laser elevation angle Backward laser azimuth angle θ aft and the back laser elevation angle It should be noted that the forward and backward azimuth and altitude angles vary with time and are not fixed constants.

[0071] In some embodiments, the step S3, determining the forward laser azimuth and forward laser altitude in the local ENU coordinate system according to the first direction velocity vector, specifically includes: establishing a local ENU coordinate system with the first direction velocity vector at the observation position of the large balloon table as the center, converting the coordinates of the first satellite in the ECEF (Earth-Centered, Earth-Fixed Coordinate System) coordinate system into the coordinates in the ENU coordinate system; and calculating the forward laser azimuth and forward laser altitude in the ENU coordinate system according to the first direction vector after the coordinate system is converted. That is, for the forward laser, it is only necessary to convert the ECEF coordinates of satellite A into ENU coordinates to calculate θ for and

[0072] In some embodiments, the step S3, determining the backward laser azimuth and backward laser altitude in the ENU coordinate system according to the second direction velocity vector, specifically includes: converting the coordinates of the second satellite in the ECEF coordinate system into coordinates in the ENU coordinate system; converting the coordinates of the second satellite's observation position in the large balloon table in the ECEF coordinate system into coordinates in the ENU coordinate system, and obtaining the direction vector of the backward radial wind speed in the ENU coordinate system; and calculating the backward laser azimuth and backward laser altitude in the ENU coordinate system according to the second direction vector after the coordinate system is converted.

[0073] For the backward laser, in addition to converting the ECEF coordinates of satellite B into ENU coordinates, it is also necessary to convert the coordinates of the observation position of satellite B in the large balloon table in the ECEF coordinate system into ENU coordinates to obtain After the direction vector in the ENU coordinate system, the corresponding θ can be calculated aft and

[0074] Specifically, the first / second direction vector in the ENU coordinate system is obtained as When the forward / backward laser elevation angle The calculation relationship between the forward / backward laser azimuth angle θ is as follows:

[0075]

[0076]

[0077]

[0078] In some embodiments, the step S4, performing horizontal wind vector inversion according to the forward radial wind speed, the forward laser azimuth, the forward laser altitude angle, the backward radial wind speed, the backward laser azimuth and the backward laser altitude angle, specifically comprises the following steps:

[0079] Step S401, determining an expression equation for the forward radial wind speed according to the forward laser azimuth angle and the forward laser altitude angle;

[0080] Step S402, determining an expression equation for the backward radial wind speed according to the backward laser azimuth angle and the backward laser altitude angle;

[0081] Step S403, determining the assumption that the forward and backward lasers are within the observation range of the large balloon table, the atmospheric wind field is evenly distributed and the vertical average wind speed is zero;

[0082] Step S404: solving the expression equation of the forward radial wind speed and the expression equation of the backward radial wind speed according to the assumed conditions.

[0083] In some embodiments, in step S401 and step S402, let u, v and w represent the wind speed components in the local east, north and up directions respectively, then the observed forward / backward radial wind speeds can be expressed as:

[0084]

[0085]

[0086] In some embodiments, in step S403, it is assumed that the forward and backward lasers are within the observation range of the large balloon table, the atmospheric wind field is evenly distributed and the vertical average wind speed is zero, that is:

[0087] In some embodiments, step S404, Then the horizontal wind vector

[0088]

[0089]

[0090] In some embodiments, the step S4, obtaining the horizontal wind vector profile, specifically includes: the horizontal wind vector profile can be constructed based on the horizontal wind vector inversion results of the large balloon table with different radii.

[0091] The following is an expanded description of the embodiments of the present application in conjunction with the accompanying drawings.

[0092] First, the nadir angle of the two satellites in the satellite coordinate system is designed to be 35 degrees (the corresponding altitude angle in the satellite coordinate system is 55 degrees), the azimuth of the observation direction of satellite A is designed to be 45 degrees, and the azimuth of the observation direction of satellite B is designed to be 135 degrees, to ensure that the observation direction of satellite A is orthogonal to the horizontal projection of the observation direction of satellite B. The satellite orbit altitude is designed to be 270km, and the true anomaly difference of the two satellites can be calculated to be 42.4mrad, the true anomaly of satellite A is designed to be 0 degrees, and the true anomaly of satellite B is 2.42751 degrees. The right ascension of the ascending node of satellite A is designed to be 58.89 degrees, and the right ascension of the ascending node of satellite B is designed to be 58.7384 degrees, so that the subsatellite point tracks of satellites A and B coincide.

[0093] Reference Figure 2 , it can be seen that satellite A and satellite B have the same sub-satellite point trajectory, and the laser beam has a changing azimuth and altitude angle in the local ENU coordinate system established with the observation point as the center.

[0094] In order to evaluate whether the dual-satellite companion flight scheme is more conducive to space-based horizontal wind vector profile remote sensing than the single-satellite scheme, the satellite orbital position on August 23, 2021 is simulated based on the two-body model (the satellite orbital position is simulated once per second), and the satellite observation position on the surface of a large balloon (radius 6378140m) orbiting the earth is calculated. In order to better invert the horizontal wind vector, the forward and backward observation positions in the single-satellite scheme (or the observation positions of the two satellites in the dual-satellite companion flight scheme) need to be as close as possible to meet the assumption of horizontal wind vector inversion, that is, the horizontal wind field within the observation range is uniformly distributed.

[0095] Reference Figure 3 ,The latitude difference of the observation positions on the surface of the large balloon for the two schemes is very small, ranging from -0.023 to 0.023 degrees, and the latitude difference in the southern hemisphere is slightly larger than the latitude difference in the northern hemisphere.

[0096] Reference Figure 4 From the distribution of longitude differences between the forward and backward observation positions, we can see that the median longitude difference in the dual-satellite companion flight scheme is 0.005 degrees, while the median longitude difference in the single-satellite scheme is -0.147 degrees, and the longitude difference in the dual-satellite companion flight scheme is significantly smaller. Both schemes show a trend of increasing longitude differences in high-latitude areas. Obviously, the dual-satellite scheme significantly reduces the longitude difference between the forward and backward observation positions by adjusting the right ascension value of the ascending node to ensure that the subsatellite point trajectories of the dual satellites coincide (satellite orbits do not coincide).

[0097] Reference Figure 5By calculating the distance between the forward and backward laser observation positions on the surface of the balloon, we can more intuitively see the advantages of the dual-satellite companion flight scheme. The distance between the observation positions of the dual-satellite is in the range of 1.2 to 2.7 km, with an average value of about 2.2 km, which is much smaller than the distance between the forward and backward observation positions of the single-satellite scheme (305m to 16.7km), with an average value of about 12km. In the single-satellite scheme, the distance in the equatorial region is the farthest, with a maximum of 16.7km; while in the polar regions, the distance is relatively close, with a minimum of only 305m.

[0098] It can be seen that the new dual-satellite companion flight wind measurement scheme proposed in the present invention can significantly reduce the distance between the forward and backward laser observation positions compared to the single-satellite scheme. The smaller the distance, the easier it is to meet the prerequisite assumption of horizontal wind vector inversion, that is, the horizontal wind field in the observation area is uniformly distributed, which is more conducive to the inversion of the horizontal wind vector.

[0099] Still taking the satellite simulation data introduced above as an example, calculate the real-time azimuth and elevation angle of the forward and backward laser in the local ENU coordinate system. Figure 6 , the distribution of the difference between the forward and backward laser azimuth angles in the local ENU coordinate system. It can be seen that the difference between the two changes dynamically at different local observation positions, basically satisfying the orthogonality of 90 degrees, and the deviation is within 0.3 degrees.

[0100] Reference Figure 7 , the elevation angle distribution of the forward and backward lasers in the local ENU coordinate system. The elevation angles of the forward and backward lasers are close to the ideal elevation angle value (53.3 degrees) in the local coordinate system, but they show obvious temporal and spatial variability, and the difference in the forward and backward elevation angles is less than 0.3 degrees.

[0101] It can be seen that if the forward and backward laser azimuth and altitude angles (fixed constants) in the satellite rigid body coordinate system are used to invert the horizontal wind vector in the observation area, it will bring obvious inversion errors. The present invention proposes a new wind vector inversion algorithm, which achieves the purpose of improving the inversion accuracy of the horizontal wind vector by establishing a local ENU coordinate system in the observation area and solving the actual forward and backward azimuth and altitude angles in real time.

[0102] The present application also provides the following embodiments: providing a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for detecting horizontal wind vector profiles by using dual-satellite companion flight wind measurement as described in any one of the above embodiments is implemented.

[0103] The present invention realizes the approximately simultaneous and co-location detection of the forward and backward radial wind speeds by designing a pair of companion satellites and a laser pointing angle, thereby solving the problem that the existing single-satellite solution cannot detect the forward and backward radial wind speeds simultaneously and co-location, and is beneficial to improving the detection accuracy of the horizontal wind vector profile of space-based remote sensing. The present invention proposes that the earth's curvature and terrain changes will cause laser pointing deviations, making the local laser azimuth and altitude angles dynamically changing rather than fixed constants. Therefore, when inverting the wind vector, if fixed constant azimuth and altitude angle values ​​are used, the inversion accuracy of the wind vector will be affected. The present invention proposes a method for real-time calculation of the laser azimuth and altitude angles, which is beneficial to improving the inversion accuracy of the horizontal wind vector.

[0104] The present invention innovatively proposes to use dual-satellite companion flight technology to achieve approximately simultaneous and co-location detection of forward and backward radial wind speeds by designing satellite orbits. This technology is conducive to improving the inversion accuracy of horizontal wind vector profiles, as well as improving the spatial coverage capability of satellites along the track direction, thereby significantly increasing the amount of observation data of satellite remote sensing wind profiles. At the same time, a new space-based horizontal wind vector profile inversion algorithm is proposed. A local northeast upper coordinate system is established with the forward laser observation point position as the center. By solving the laser beam pointing (local azimuth and altitude angle) in real time, the azimuth and altitude angles are no longer approximated using fixed constant values, which reduces the laser pointing deviation caused by the earth's curvature and terrain height differences, and improves the inversion accuracy of the horizontal wind vector profile.

[0105] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0106] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0107] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0108] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0109] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0110] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0111] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0112] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0113] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for detecting horizontal wind vector profiles by using dual satellite companion flight wind measurement, characterized in that: include: Acquire a first direction velocity vector, where the first direction velocity vector is a velocity component in the direction of the forward laser beam measured by the first satellite, that is, a forward radial wind speed; Acquire a second direction velocity vector, where the second direction velocity vector is a velocity component in the direction of a backward laser beam measured by a second satellite, that is, a backward radial wind speed; wherein the first satellite and the second satellite are companion satellites; Determine a forward laser azimuth and a forward laser altitude in a local coordinate system according to the first direction velocity vector, and determine a backward laser azimuth and a backward laser altitude in the same local coordinate system according to the second direction velocity vector; Perform horizontal wind vector inversion according to the forward radial wind speed, the forward laser azimuth, the forward laser altitude, the backward radial wind speed, the backward laser azimuth and the backward laser altitude to obtain a horizontal wind vector profile; this step includes: determining an expression equation for the forward radial wind speed according to the forward laser azimuth and the forward laser altitude; determining an expression equation for the backward radial wind speed according to the backward laser azimuth and the backward laser altitude; determining an assumption that the atmospheric wind field is uniformly distributed and the vertical average wind speed is zero within the observation range of the forward and backward lasers in the large balloon table; solving the expression equations for the forward radial wind speed and the backward radial wind speed according to the assumptions; Let u, v and w represent the local wind speed components in the east, north and up directions respectively, then we have, The expression equation of the forward radial wind speed is: in, is the forward laser azimuth, is the forward laser elevation angle, the forward radial wind speed is the measurement data of the first satellite; The expression equation of the backward radial wind speed is: in, is the backward laser azimuth, is the backward laser elevation angle, and the backward radial wind speed is the measurement data of the second satellite; The expression equations of the forward radial wind speed and the backward radial wind speed are solved according to the assumptions to obtain the horizontal wind vector ( )include: According to the assumptions: , , ; make , , , , then: The nadir angles of the laser beams pointing to the first satellite and the second satellite in the satellite coordinate system are the same; the observation direction of the first satellite is orthogonal to the horizontal projection of the observation direction of the second satellite on the surface; the true anomaly difference between the first satellite and the second satellite is equal to the angle corresponding to the difference in the on-orbit flight time between the two satellites; the right ascension difference of the ascending node of the first satellite and the second satellite satisfies: ;in, is the right ascension difference of the ascending node between the orbital planes, is the Earth's rotation angular velocity, is the mean anomaly angle difference, is the satellite’s angular velocity in orbit.

2. The method according to claim 1, characterized in that The step of determining the forward laser azimuth angle and the forward laser altitude angle in the local coordinate system according to the first direction velocity vector comprises: A local northeast-upward coordinate system is established with the observation position of the first direction velocity vector on the large balloon table as the center; Converting the coordinates of the first satellite in the Earth-centered Earth-fixed coordinate system to the coordinates of the local Northeast-upward coordinate system; According to the first direction vector after the coordinate system is converted, the forward laser azimuth angle and the forward laser altitude angle in the northeast upper coordinate system are calculated.

3. The method according to claim 2, characterized in that The method of determining the backward laser azimuth angle and the backward laser altitude angle in the same local coordinate system according to the second direction velocity vector comprises: Convert the coordinates of the second satellite in the Earth-centered Earth-fixed coordinate system to the coordinates of the local northeast-upper coordinate system; The coordinates of the observation position of the second satellite in the large balloon table in the earth-centered earth-fixed coordinate system are converted into coordinates in the local northeast upper coordinate system to obtain the second direction vector of the backward radial wind speed in the local northeast upper coordinate system; According to the second direction vector after the coordinate system is converted, the backward laser azimuth and the backward laser altitude angle in the local northeast upper coordinate system are calculated.

4. The method according to claim 3, characterized in that The calculation of the forward / backward laser azimuth angle and the forward / backward laser altitude angle comprises: The first / second direction vector in the local northeast coordinate system is obtained as , then the corresponding forward / backward laser azimuth is , the corresponding forward / backward laser altitude angle is .

5. The method according to claim 1, characterized in that The obtaining of the horizontal wind vector profile comprises: The horizontal wind vector profile can be constructed based on the horizontal wind vector inversion results of the large balloon table with different radii.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the operating steps of the method according to any one of claims 1 to 5 are implemented.

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