Observation route planning methods, devices, electronic equipment and storage media

Abstract

This invention provides a method, apparatus, electronic device, and storage medium for planning observation flight paths, relating to the field of airborne remote sensing technology. The method includes: determining the observation geometric angles at various times during the transit of the reference satellite based on the orbital information of a reference satellite and the position information of the observed target; determining the maximum elevation angle among the observation geometric angles, and defining the time corresponding to the maximum elevation angle as the transit time of the reference satellite; determining flight path parameters for planning the observation flight path based on the elevation angle, azimuth angle, and observation resolution at the transit time, and generating the observation flight path using the flight path parameters. This invention enables an airborne platform to point at the target with identical azimuth and elevation angles at the satellite transit time, thereby obtaining air-space collaborative observation data with strong observation geometric consistency and effectively improving observation results.

Description

Technical Field

[0001] This invention relates to the field of airborne remote sensing technology, and in particular to a method, apparatus, electronic device, and storage medium for planning observation routes. Background Technology

[0002] With the rapid development of Earth observation technology, single-platform observation methods have inherent limitations in terms of timeliness, resolution, coverage, or observation dimensions, making it difficult to meet the growing demand for continuous, detailed, and real-time global sensing. Against this backdrop, space-air collaborative observation has emerged as a new integrated and intelligent observation paradigm, and has rapidly become a key technological support for fields such as Earth system science, resource and environmental monitoring, and national security.

[0003] To improve the accuracy of satellite data calibration or to verify the simulation results of satellite observation target characteristics, existing observation route planning methods are usually based on the satellite's transit time and area, and the observation route is planned on an airborne platform to conduct observations as simultaneously as possible. However, it is difficult to obtain aerial image data that is consistent with the observation perspective of the spaceborne platform based on the satellite's transit time and area, resulting in poor observation results. Summary of the Invention

[0004] This invention provides an observation flight path planning method, device, electronic equipment, and storage medium to solve the technical problem in the prior art that it is difficult to obtain aerial image data consistent with the observation perspective of the space-based platform based on the satellite transit time and area, resulting in poor observation effect.

[0005] This invention provides a method for planning observation routes, comprising: Based on the orbital information of the reference satellite and the position information of the observed target, the observation geometric angles at each moment during the transit of the reference satellite are determined; wherein, the observation geometric angles include the elevation angle and the azimuth angle. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, the route parameters for planning the observation route are determined, and the observation route is generated using the route parameters.

[0006] According to the observation flight path planning method provided by the present invention, determining the observation geometric angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observation target includes: Based on the orbital information of the reference satellite and the position information of the observed target, the local horizontal coordinates of the reference satellite relative to the observed target at each moment during its transit are calculated. Based on the local horizontal coordinates, the observed geometric angles at each moment during the transit period are calculated.

[0007] According to the observation flight path planning method provided by the present invention, determining the maximum elevation angle in the observation geometry includes: A first coordinate point string with time reference is generated based on the observed geometric angle; The coordinate point string in the first coordinate point string whose elevation angle is greater than the preset elevation angle threshold is taken as the second coordinate point string; Iterate through the elevation angles of each coordinate point in the second coordinate point string, and determine the maximum elevation angle at each time point.

[0008] According to the observation route planning method provided by the present invention, the route parameters include route altitude, route azimuth, route start point, and route end point; The step of determining the route parameters for planning the observation route based on the elevation angle, azimuth angle, and observation resolution at the time of overpass includes: Determine the flight path altitude based on the observation resolution; Determine the azimuth of the flight path based on the azimuth at the time of the overhead crossing; Based on the altitude angle at the time of overhead passage and the flight path altitude, determine the horizontal displacement distance from the flight path to the observed target; The starting point and ending point of the route are determined based on the horizontal displacement distance.

[0009] According to the observation route planning method provided by the present invention, determining the route start point and route end point based on the horizontal displacement distance includes: Determine the planar coordinates of the observed target; The perpendicular coordinates of the flight path are determined based on the plane coordinates, the horizontal displacement distance, and the reference rotation angle. The starting point and ending point of the route are determined based on the perpendicular coordinates of the route, the reference rotation angle, and the route length.

[0010] According to the observation route planning method provided by the present invention, the reference rotation angle is determined based on the route azimuth angle.

[0011] The present invention also provides an observation route planning device, comprising: The observation geometry angle determination module is used to determine the observation geometry angle at each moment during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observation target; wherein, the observation geometry angle includes the elevation angle and the azimuth angle; The overpass time determination module is used to determine the maximum elevation angle in the observation geometry and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; The observation route planning module is used to determine the route parameters for planning the observation route based on the elevation angle, azimuth angle and observation resolution at the time of the overpass, and to generate the observation route using the route parameters.

[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the observation route planning method as described above.

[0013] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the observation route planning method as described above.

[0014] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the observation route planning method as described above.

[0015] This invention calculates the elevation and azimuth angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observed target. It determines the transit time and its precise angle corresponding to the maximum elevation angle, and determines various flight path parameters in combination with observation resolution constraints, ultimately generating an observation flight path. This enables the airborne platform to point at the target with the exact same azimuth and elevation angles at the time of satellite transit, achieving strictly identical aerial data acquisition with the spaceborne platform. This results in geometrically consistent air-space collaborative observation data, effectively eliminating inversion errors caused by angular heterogeneity, and significantly improving the observation effect in application scenarios such as satellite calibration and target characteristic deduction.

[0016] Furthermore, this invention generates a first set of coordinate points in chronological order based on observed geometric angles, then selects points with elevation angles greater than a preset threshold to form a second set of coordinate points. Finally, it iterates through the second set of coordinate points to determine the maximum elevation angle. This effectively eliminates invalid data that is severely affected by atmospheric attenuation, terrain obstruction, and geometric distortion during low elevation angle periods, reducing the computational burden of subsequent processing. At the same time, it ensures that the maximum elevation angle is calculated solely based on the second set of coordinate points, thereby accurately pinpointing the satellite's overhead time and its optimal observation angle. This provides a reliable time and angle reference for subsequent space-based flight path design, significantly improving the accuracy of space-air collaborative observation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the observation route planning method provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the trajectory of a reference satellite during its transit, provided by the present invention.

[0020] Figure 3 This is a schematic diagram illustrating the relationship between the satellite orbit and the observation target provided by the present invention.

[0021] Figure 4 This is a schematic diagram illustrating the relative relationship between the observation route and the observation target provided by the present invention.

[0022] Figure 5 This is a schematic diagram of the observation route planning device provided by the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] The embodiments of the present invention are applicable to scenarios that require strict same-view observation between air-based (flying equipment) and space-based (satellite) platforms, such as: simulation and verification of on-orbit imaging effects before the launch of a new type of remote sensing satellite, high-precision radiometric and geometric calibration of on-orbit satellites, target characteristic analysis and stealth effect evaluation, etc.

[0026] Figure 1 This is a flowchart illustrating the observation route planning method provided by the present invention, as shown below. Figure 1 As shown, the method includes the following: S1. Based on the orbital information of the reference satellite and the position information of the observation target, determine the observation geometric angles at each moment during the transit of the reference satellite; wherein, the observation geometric angles include the elevation angle and the azimuth angle; In this embodiment of the invention, the reference satellite refers to a satellite used as a reference benchmark in space-air collaborative observation. The reference satellite can be a satellite already launched and functioning normally in orbit, or a satellite under development awaiting launch, whose orbital parameters are known and used for advance simulation. Orbital information is a set of data describing the satellite's trajectory in space, which can be in the publicly available TLE (two-line orbital elements) format, including the satellite's orbital inclination, right ascension of the ascending node, eccentricity, perigee distance, and mean perigee angle. Orbital information is the fundamental data for calculating the satellite's position at any given time. The observation target is a specific point or small area on the ground, such as an agricultural experimental station, a city landmark, a forest monitoring plot, a special facility, or a bridge. The location of the observation target is uniquely determined by longitude, latitude, and altitude. Each moment during transit does not refer to the entire time of the satellite's flight, but specifically to the entire time period from when the satellite rises above the observed horizon (elevation angle greater than 0°) to when it falls below the horizon again. For low-Earth orbit remote sensing satellites, a transit typically lasts 10 to 15 minutes, during which the satellite's geometric relationship with the target continuously changes. The observation geometry includes elevation and azimuth. Elevation is the angle between the line of sight from a ground target looking up at the satellite and the local horizon. 0° indicates the satellite is exactly on the horizon, and 90° indicates the satellite is directly overhead. A larger elevation angle means a shorter atmospheric path for the satellite signal, less atmospheric attenuation and distortion, and higher image quality. Azimuth is the direction of the projection of the line of sight from a ground target looking up at the satellite onto the horizontal plane, measured clockwise from true north. 0° is true north, 90° is true east, 180° is true south, and 270° is true west. Azimuth determines the direction the satellite is coming from and going, which is crucial for subsequent space-based flight path design.

[0027] In this embodiment of the invention, two rows of root numbers for a reference satellite can be downloaded from a publicly available orbit database to obtain the latest TLE orbit parameters of the reference satellite. The longitude, latitude, and altitude data of the target can be extracted using GNSS field measurements or from high-precision maps.

[0028] This invention can estimate a rough transit window (e.g., a transit within the next 24 hours) based on the satellite's orbital altitude and the latitude of the ground target. Preliminary screening can be performed using rapid transit forecasting software, and a standard orbital model (such as SGP4 / SDP4) can be used to numerically integrate the transit time interval (TLE) to calculate the satellite's three-dimensional coordinates in the geocentric inertial frame (ECI) or geocentric earth-fixed frame (ECEF) at each discrete moment within the transit window. The difference between the satellite coordinates and the ground target coordinates is used to obtain the satellite's vector relative to the target. This vector is then transformed to the local horizontal coordinate system (ENU: East, North, Sky) with the target as the origin using a rotation matrix. Finally, the elevation and azimuth angles are calculated using the arctangent function.

[0029] Please see Figure 2This is a schematic diagram of the trajectory of a reference satellite during its transit, provided in an embodiment of the present invention.

[0030] S2. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; In this embodiment of the invention, the maximum elevation angle is the maximum elevation angle reached by the satellite relative to the ground target during an entire overpass. Overpass moment: the precise instant in which the maximum elevation angle occurs, typically accurate to the second or sub-second. At this moment, the line connecting the satellite and the target is closest to the zenith direction, atmospheric interference is minimal, ground geometric deformation is minimal, and the signal-to-noise ratio is highest. The overpass moment can be used as the data acquisition moment, and the elevation and azimuth angles at this moment serve as reference elevation and reference azimuth angles for airborne remote sensing flight path design.

[0031] S3. Based on the elevation angle, azimuth angle and observation resolution at the time of the overpass, determine the route parameters for planning the observation route, and generate the observation route using the route parameters.

[0032] In this embodiment of the invention, the observation resolution refers to the Ground Sampling Distance (GSD), which is the actual ground size represented by one pixel in an aerial image. The resolution is determined by mission requirements. Flight path parameters: A set of quantified data describing an aerial path that can be used for autonomous aircraft flight, including at least one of the following: flight path altitude, the distance of the aircraft relative to a ground target in the altitude direction; flight path azimuth, the direction of the flight path on the ground; flight path start and end points, the latitude, longitude, and altitude of two three-dimensional points in the air; flight path length, the distance from the start point to the end point.

[0033] This invention can be applied to crop monitoring. For example, an organization plans to launch a hyperspectral satellite for crop monitoring. The satellite has not yet been launched, but its orbital parameters have been designed. To verify the satellite's imaging quality and the effectiveness of subsequent inversion algorithms in advance, it is necessary to use an aircraft to simulate the satellite's perspective and obtain airborne hyperspectral data of the same area.

[0034] The specific process is as follows: Select a crop experimental field as the observation target. Based on the satellite's TLE parameters, calculate the maximum elevation angle and overpass time for a certain transit within the next week, for example, 10:35:20 AM on a certain day, with an elevation angle of 82° and an azimuth angle of 150°. Based on the mission requirement of 0.2-meter resolution and the parameters of the camera on the aircraft, calculate the flight altitude to be 1200 meters. Then, design the flight path according to the above S3 steps: flight path azimuth angle = 150° – 90° = 60°. The horizontal displacement distance is calculated from the altitude and elevation angle to be approximately 168 meters. Generate the coordinates of the start and end points. On the scheduled date, the aircraft takes off ahead of time, flies to the midpoint of the flight path at 10:35:20 AM on time, and takes pictures. After processing, the obtained data can be used to simulate the imaging effect of the satellite in orbit, verify the accuracy of the inversion algorithm, and discover potential problems in the satellite design, such as anomalies in the reflection of specific ground features at different angles.

[0035] This invention calculates the elevation and azimuth angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observed target. It determines the transit time and its precise angle corresponding to the maximum elevation angle, and determines various flight path parameters in combination with observation resolution constraints, ultimately generating an observation flight path. This enables the airborne platform to point at the target with the exact same azimuth and elevation angles at the satellite transit time, achieving strictly identical aerial data acquisition with the spaceborne platform. This results in geometrically consistent air-space collaborative observation data, effectively eliminating inversion errors caused by angular heterogeneity and significantly improving the observation effects in application scenarios such as satellite calibration and target characteristic deduction.

[0036] Please see Figure 3 This is a schematic diagram illustrating the relationship between a satellite orbit and an observation target, provided by an embodiment of the present invention. Figure 3 The red pentagon in the center is the observation target.

[0037] Please see Figure 4 This is a schematic diagram illustrating the relative relationship between an observation route and an observation target, provided by an embodiment of the present invention.

[0038] In one embodiment, step S1, determining the observation geometry angle at each moment during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observation target, includes: S11. Based on the orbital information of the reference satellite and the position information of the observation target, calculate the local horizontal coordinates of the reference satellite relative to the observation target at each moment during its transit. In this embodiment of the invention, the location information of the observed target includes longitude λ and latitude. And altitude h. In this embodiment of the invention, the orbital information of the reference satellite can be calculated using the SGP4 / SDP4 satellite orbit calculation algorithm model based on the TLE orbital parameters of the reference satellite, and then the geocentric inertial coordinates of the reference satellite in the geocentric inertial coordinate system at a specified time can be calculated.

[0039] According to the coordinate transformation formula, the reference satellite geocentric inertial coordinates are converted to reference satellite geostationary coordinates in the Earth-fixed coordinate system. The transformation formula is as follows: in, For Earth-fixed coordinates, Using geocentric inertial coordinates, It is a rotation matrix.

[0040] Rotation matrix The expression is as follows: in, Greenwich True Sidereal Time (GTST) represents the angle between the vernal equinox and the Greenwich Meridian.

[0041] In this embodiment of the invention, the ground-fixed coordinates of the observed target are calculated based on the target's location information, as expressed below: Where N is the radius of curvature of the zonal loop, its expression is as follows: in, For the Earth's semi-major axis, Let be the square of the first eccentricity of the ellipsoid.

[0042] The first position vector rsat=(X,Y,Z) is determined based on the reference satellite's ground-fixed coordinates. The second position vector, relative to the observed target, is calculated using this position vector and the ground-fixed coordinates of the observed target. The expression is as follows: In this embodiment of the invention, based on the second position vector, the local horizontal coordinates of the satellite relative to the observed target at each moment during its transit are referenced. The definition of the local horizontal coordinate system (ENU) includes: East (E): a unit vector eastward along the latitude circle; North (N): a unit vector northward along the longitude circle; and Sky (U): a unit vector upward along the ellipsoid normal.

[0043] Transformation matrix The expression is as follows: The expression for the local horizontal coordinates of the reference satellite relative to the observed target at various times during its transit is as follows: S12. Based on the local horizontal coordinates, calculate the observed geometric angles at each moment during the transit.

[0044] In this embodiment of the invention, the elevation angle The expression is as follows: Or equivalent to: The altitude angle ranges from -90° to 90°, with positive values ​​being the elevation angle.

[0045] Azimuth The expression is as follows: Where atan2(E, N) is the arctangent function in the four quadrants. The azimuth range is -180° to 180°, or converted to 0° to 360°. The azimuth can be defined as rotating clockwise from true north to the horizontal projection direction of the satellite.

[0046] Based on the orbital information of the reference satellite and the position information of the observation target, this invention accurately calculates the local horizontal coordinates of the reference satellite relative to the observation target at each moment during its transit, and calculates the elevation angle and azimuth angle of the continuous time series accordingly. This allows for the complete acquisition of the observation geometry angle at each moment during the satellite's transit, thus providing a high-precision data foundation for the subsequent accurate selection of the maximum elevation angle and the overpass time, which is beneficial for improving the observation effect.

[0047] In one embodiment, step S2, determining the maximum elevation angle among the observed geometric angles, includes: S21. Generate a first coordinate point string with time reference based on the observed geometric angle; In this embodiment of the invention, the horizontal axis represents time and the vertical axis represents angle values. The observed geometric angles calculated based on each moment during the satellite's transit are arranged in chronological order. Each moment corresponds to a data point containing a timestamp, elevation angle, and azimuth angle. All data points constitute a time sequence, called the first coordinate point string. The first coordinate point string completely records the angle changes of the satellite from rising above the horizon (elevation angle ≈ 0°) to its highest point and then setting again (elevation angle ≈ 0°).

[0048] S22. Take the coordinate point string in the first coordinate point string whose elevation angle is greater than the preset elevation angle threshold as the second coordinate point string; In this embodiment of the invention, a preset altitude threshold, such as 10° or 15°, can be set according to actual task requirements. Data points with all altitude angles exceeding the preset altitude threshold are selected from the first coordinate point string, and these points are arranged in chronological order to form a second coordinate point string. The second coordinate point string corresponds to the effective observation window of the reference satellite, and can eliminate periods with severe atmospheric interference and poor observation quality at low altitude angles. When the altitude angle is below the threshold, the satellite signal has an excessively long path through the atmosphere, leading to radiation attenuation, geometric distortion, multipath effects, etc., resulting in unreliable data. The second coordinate point string only retains angle data within the effective observation period, which can effectively reduce the amount of subsequent calculations.

[0049] S23. Traverse the elevation angle of each coordinate point in the second coordinate point string and determine the maximum elevation angle at each time.

[0050] In this embodiment of the invention, each data point in the second coordinate point string is traversed sequentially, its elevation angle value is read, and by comparing each elevation angle, the largest elevation angle is found, and the time t and its azimuth angle corresponding to the value are recorded.

[0051] This invention generates a first set of coordinate points in chronological order based on observed geometric angles, then selects points with elevation angles greater than a preset threshold to form a second set of coordinate points. Finally, it iterates through the second set of coordinate points to determine the maximum elevation angle. This effectively eliminates invalid data that is severely affected by atmospheric attenuation, terrain obstruction, and geometric distortion during low elevation angle periods, reducing the computational burden of subsequent processing. At the same time, it ensures that the maximum elevation angle is calculated solely based on the second set of coordinate points, thereby accurately pinpointing the satellite's overhead time and its optimal observation angle. This provides a reliable time and angle reference for subsequent space-based flight path design, significantly improving the accuracy of space-air collaborative observation.

[0052] In one embodiment, the route parameters include route altitude, route azimuth, route start point, and route end point; Step S3: Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, determine the route parameters for planning the observation route, including: S31. Determine the flight path altitude based on the observation resolution; In this embodiment of the invention, the latitude and longitude coordinates of the observed target can be projected into the UTM coordinate system to obtain the coordinates X, Y, Z.

[0053] In this embodiment of the invention, taking an optical payload as an example, the flight path height H is equal to the observation resolution divided by the pixel physical size multiplied by the focal length, as shown in the following expression: H = GSD / PixelSize Focal Where GSD is the observation resolution, PixelSize is the physical size of the pixel, and Focal is the focal density. It is the focal length.

[0054] S32. Determine the azimuth of the route based on the azimuth at the time of the overhead crossing; In this embodiment of the invention, the azimuth angle of the flight path is equal to the azimuth angle at the time of the reference satellite's overhead transit minus 90 degrees, as expressed below: F a =S a -90 Among them, F a S is the azimuth angle of the flight path. a The azimuth angle is used as a reference for the time when the satellite passes overhead.

[0055] S33. Determine the horizontal displacement distance from the route to the observed target based on the elevation angle at the time of overhead crossing and the route elevation; In this embodiment of the invention, the expression for the horizontal displacement distance D from the flight path to the observed target is as follows: D=H Tan ) in, The elevation angle at the moment of overhead crossing. For aerial remote sensing observation, if this value is greater than half of the camera's side field of view (FOV), i.e., FOV / 2, then ( The value is forced to be equal to FOV / 2 to prevent the aerial camera from being unable to capture ground targets and thus hindering collaborative observation when the aerial remote sensing observation side's viewpoint is outside the field of view.

[0056] S34. Determine the starting point and ending point of the route based on the horizontal displacement distance.

[0057] This invention directly constrains flight altitude by observation resolution, ensuring that the acquired aerial imagery meets mission resolution requirements. Furthermore, this invention uniquely determines the flight path azimuth angle using the satellite azimuth angle, and the horizontal displacement distance is uniquely determined by the satellite elevation angle and the flight path altitude. This ensures that the observed geometric angles reproduced by the aircraft are strictly consistent with those of the reference satellite, which is beneficial for improving the reliability of air-space collaborative observation.

[0058] In one embodiment, step S34, determining the starting point and ending point of the route based on the horizontal displacement distance, includes: S341. Determine the plane coordinates of the observed target; In this embodiment of the invention, the observed target is projected into UTM coordinates, and its planar coordinates are taken as (X0, Y0).

[0059] S342. Determine the perpendicular coordinates of the flight path based on the plane coordinates, the horizontal displacement distance, and the reference rotation angle; In this embodiment of the invention, the perpendicular coordinate of the flight path (X)d Y d The expression for ) is as follows: Where D is the horizontal displacement distance from the flight path to the observed target. The reference rotation angle (polar coordinate rotation angle) is based on the east direction, and its expression is as follows: .

[0060] S343. Determine the starting point and ending point of the route based on the perpendicular coordinates of the route, the reference rotation angle, and the route length.

[0061] In this embodiment of the invention, the route origin ( ) and route destination ( The expression for ) is as follows: in, For route length, and These represent the polar coordinate rotation angles with the eastward direction as a reference. .

[0062] In this embodiment of the invention, the coordinates of the starting point and ending point of the route can be converted into latitude and longitude coordinates through UTM projection transformation for planning observation routes.

[0063] This invention determines the planar coordinates of the observation target and calculates the perpendicular coordinates of the flight path based on the horizontal displacement distance and the reference rotation angle. Then, it accurately generates the start and end points of the flight path by combining the flight path length and the rotation angle. It can convert the observation geometry angle at the time of the reference satellite's overhead pass into a spatial path that can be directly navigated by the aircraft based on the observation resolution, horizontal displacement distance and flight path length set by the mission. This allows airborne platforms (such as flight equipment) to obtain aerial image data with the same observation perspective as space-based platforms (such as satellites), thereby effectively improving the observation effect.

[0064] Implementing the embodiments of the present invention has the following beneficial effects: This invention calculates the elevation and azimuth angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observed target. It determines the transit time and its precise angle corresponding to the maximum elevation angle, and determines various flight path parameters in combination with observation resolution constraints, ultimately generating an observation flight path. This enables the airborne platform to point at the target with the exact same azimuth and elevation angles at the satellite transit time, achieving strictly identical aerial data acquisition with the spaceborne platform. This results in geometrically consistent air-space collaborative observation data, effectively eliminating inversion errors caused by angular heterogeneity and significantly improving the observation effects in application scenarios such as satellite calibration and target characteristic deduction.

[0065] Furthermore, in this embodiment of the invention, by generating a first set of coordinate points in chronological order based on the observed geometric angles, and then selecting points with elevation angles greater than a preset threshold to form a second set of coordinate points, and finally traversing the second set of coordinate points to determine the maximum elevation angle, invalid data severely affected by atmospheric attenuation, terrain obstruction, and geometric distortion during low elevation angle periods can be effectively eliminated, reducing the computational burden of subsequent processing. At the same time, it ensures that the solution of the maximum elevation angle is based solely on the second set of coordinate points, thereby accurately locking the satellite overhead time and its optimal observation angle, providing a reliable time and angle reference for subsequent space-based flight path design, and significantly improving the accuracy of space-air collaborative observation.

[0066] The observation route planning device provided by the present invention is described below. The observation route planning device described below and the observation route planning method described above can be referred to in correspondence.

[0067] The embodiments of the present invention are applicable to scenarios that require strict same-view observation between air-based (flying equipment) and space-based (satellite) platforms, such as: simulation and verification of on-orbit imaging effects before the launch of a new type of remote sensing satellite, high-precision radiometric and geometric calibration of on-orbit satellites, target characteristic analysis and stealth effect evaluation, etc.

[0068] Please see Figure 5 The present invention also provides an observation route planning device, comprising: The observation geometry angle determination module 510 is used to determine the observation geometry angle at each moment during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observation target; wherein, the observation geometry angle includes the elevation angle and the azimuth angle; In this embodiment of the invention, the reference satellite refers to a satellite used as a reference benchmark in space-air collaborative observation. The reference satellite can be an already launched and operational satellite in orbit (used for calibration or verification), or a satellite under development awaiting launch (whose orbital parameters are known and used for advance simulation). Orbital information is a set of data describing the satellite's trajectory in space, which can be in the publicly available TLE (two-line orbital elements) format, including the satellite's orbital inclination, right ascension of the ascending node, eccentricity, perigee distance, and mean perigee angle. Orbital information is the fundamental data for calculating the satellite's position at any given time. The observation target is a specific point or small area on the ground, such as an agricultural experimental station, a city landmark, a forest monitoring plot, a special facility, or a bridge. The location of the observation target is uniquely determined by longitude, latitude, and altitude. The times during transit do not refer to the entire time of the satellite's flight, but specifically to the entire period from when the satellite rises above the observed horizon (elevation angle greater than 0°) to when it falls below the horizon again. For low-Earth orbit remote sensing satellites, a single transit typically lasts 10 to 15 minutes. During this time, the satellite's geometric relationship with the target continuously changes. The observation geometry includes elevation and azimuth. Elevation is the angle between the line of sight from a ground target looking up at the satellite and the local horizon. 0° indicates the satellite is exactly on the horizon, and 90° indicates the satellite is directly overhead (zenith). A larger elevation angle results in a shorter atmospheric path for the satellite signal, less atmospheric attenuation and distortion, and higher image quality. Azimuth is the direction of the projection of the line of sight from a ground target looking up at the satellite onto the horizontal plane, measured clockwise from true north. 0° is true north, 90° is true east, 180° is true south, and 270° is true west. Azimuth determines the direction the satellite is coming from and going, which is crucial for subsequent space-based flight path design.

[0069] In this embodiment of the invention, two rows of root numbers for a reference satellite can be downloaded from a public orbit database (such as Celestrak) to obtain the latest TLE orbit parameters of the reference satellite. The longitude, latitude, and altitude data of the target can be extracted using GNSS field measurements or from high-precision maps.

[0070] This invention can estimate a rough transit window (e.g., a transit within the next 24 hours) based on the satellite's orbital altitude and the latitude of the ground target. Preliminary screening can be performed using rapid transit forecasting software, and a standard orbital model (such as SGP4 / SDP4) can be used to numerically integrate the transit time interval (TLE) to calculate the satellite's three-dimensional coordinates in the geocentric inertial frame (ECI) or geocentric earth-fixed frame (ECEF) at each discrete moment within the transit window. The difference between the satellite coordinates and the ground target coordinates is used to obtain the satellite's vector relative to the target. This vector is then transformed to the local horizontal coordinate system (ENU: East, North, Sky) with the target as the origin using a rotation matrix. Finally, the elevation and azimuth angles are calculated using the arctangent function.

[0071] The overpass time determination module 520 is used to determine the maximum elevation angle in the observation geometry angle, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; In this embodiment of the invention, the maximum elevation angle is the maximum elevation angle reached by the satellite relative to the ground target during an entire overpass. Overpass moment: the precise instant in which the maximum elevation angle occurs, typically accurate to the second or sub-second. At this moment, the line connecting the satellite and the target is closest to the zenith direction, atmospheric interference is minimal, ground geometric deformation is minimal, and the signal-to-noise ratio is highest. The overpass moment can be used as the data acquisition moment, and the elevation and azimuth angles at this moment serve as reference altitude and reference azimuth angles for airborne remote sensing flight path design.

[0072] The observation route planning module 530 is used to determine the route parameters for planning the observation route based on the elevation angle, azimuth angle and observation resolution at the time of the overpass, and to generate the observation route using the route parameters.

[0073] In this embodiment of the invention, the observation resolution refers to the Ground Sampling Distance (GSD), which is the actual ground size represented by one pixel in an aerial image. The resolution is determined by mission requirements. Flight path parameters: A set of quantified data describing an aerial path that can be used for autonomous flight of the aircraft, including at least one of the following: flight path altitude, the vertical distance of the aircraft relative to a ground target; flight path azimuth, the direction of the flight path on the ground; flight path start and end points, the latitude, longitude, and altitude of two three-dimensional points in the air; and flight segment length, the distance from the start point to the end point.

[0074] This invention can be applied to crop monitoring. For example, an organization plans to launch a hyperspectral satellite for crop monitoring. The satellite has not yet been launched, but its orbital parameters have been designed. To verify the satellite's imaging quality and the effectiveness of subsequent inversion algorithms in advance, it is necessary to use an aircraft to simulate the satellite's perspective and obtain airborne hyperspectral data of the same area.

[0075] The specific process is as follows: Select a crop experimental field as the observation target. Based on the satellite's TLE parameters, calculate the maximum elevation angle and overpass time for a certain transit within the next week, for example, 10:35:20 AM on a certain day, with an elevation angle of 82° and an azimuth angle of 150°. Based on the mission requirement of 0.2-meter resolution and the parameters of the camera on the aircraft, calculate the flight altitude to be 1200 meters. Then, design the flight path according to the above S3 steps: flight path azimuth angle = 150° – 90° = 60°. The horizontal displacement distance is calculated from the altitude and elevation angle to be approximately 168 meters. Generate the coordinates of the start and end points. On the scheduled date, the aircraft takes off ahead of time, flies to the midpoint of the flight path at 10:35:20 AM on time, and takes pictures. After processing, the obtained data can be used to simulate the imaging effect of the satellite in orbit, verify the accuracy of the inversion algorithm, and discover potential problems in the satellite design, such as anomalies in the reflection of specific ground features at different angles.

[0076] This invention calculates the elevation and azimuth angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observed target. It determines the transit time and its precise angle corresponding to the maximum elevation angle, and determines various flight path parameters in combination with observation resolution constraints, ultimately generating an observation flight path. This enables the airborne platform to point at the target with the exact same azimuth and elevation angles at the satellite transit time, achieving strictly identical aerial data acquisition with the spaceborne platform. This results in geometrically consistent air-space collaborative observation data, effectively eliminating inversion errors caused by angular heterogeneity, and significantly improving the observation effects in application scenarios such as satellite calibration, target characteristic extrapolation, and disaster emergency monitoring.

[0077] In one embodiment, determining the observation geometry angle at each moment during the transit of the reference satellite, based on the orbital information of the reference satellite and the position information of the observation target, includes: Based on the orbital information of the reference satellite and the position information of the observed target, the local horizontal coordinates of the reference satellite relative to the observed target at each moment during its transit are calculated. In this embodiment of the invention, the location information of the observed target includes longitude λ and latitude. And altitude h. In this embodiment of the invention, the orbital information of the reference satellite can be calculated using the SGP4 / SDP4 satellite orbit calculation algorithm model based on the TLE orbital parameters of the reference satellite, and then the geocentric inertial coordinates of the reference satellite in the geocentric inertial coordinate system at a specified time can be calculated.

[0078] Based on the local horizontal coordinates, the observed geometric angles at each moment during the transit period are calculated.

[0079] In one embodiment, determining the maximum elevation angle among the observed geometric angles includes: A first coordinate point string with time reference is generated based on the observed geometric angle; The coordinate point string in the first coordinate point string whose elevation angle is greater than the preset elevation angle threshold is taken as the second coordinate point string; Iterate through the elevation angles of each coordinate point in the second coordinate point string, and determine the maximum elevation angle at each time point.

[0080] In one embodiment, the route parameters include route altitude, route azimuth, route start point, and route end point; The step of determining the route parameters for planning the observation route based on the elevation angle, azimuth angle, and observation resolution at the time of overpass includes: Determine the flight path altitude based on the observation resolution; Determine the azimuth of the flight path based on the azimuth at the time of the overhead crossing; Based on the altitude angle at the time of overhead passage and the flight path altitude, determine the horizontal displacement distance from the flight path to the observed target; The starting point and ending point of the route are determined based on the horizontal displacement distance.

[0081] In one embodiment, determining the starting point and ending point of the route based on the horizontal displacement distance includes: Determine the planar coordinates of the observed target; The perpendicular coordinates of the flight path are determined based on the plane coordinates, the horizontal displacement distance, and the reference rotation angle. The starting point and ending point of the route are determined based on the perpendicular coordinates of the route, the reference rotation angle, and the route length.

[0082] In one embodiment, the reference rotation angle is determined based on the azimuth angle of the flight path.

[0083] This invention calculates the elevation and azimuth angles at various times during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observed target. It determines the transit time and its precise angle corresponding to the maximum elevation angle, and determines various flight path parameters in combination with observation resolution constraints, ultimately generating an observation flight path. This enables the airborne platform to point at the target with the exact same azimuth and elevation angles at the satellite transit time, achieving strictly identical aerial data acquisition with the spaceborne platform. This results in geometrically consistent air-space collaborative observation data, effectively eliminating inversion errors caused by angular heterogeneity and significantly improving the observation effects in application scenarios such as satellite calibration and target characteristic deduction.

[0084] Furthermore, in this embodiment of the invention, by generating a first set of coordinate points in chronological order based on the observed geometric angles, and then selecting points with elevation angles greater than a preset threshold to form a second set of coordinate points, and finally traversing the second set of coordinate points to determine the maximum elevation angle, invalid data severely affected by atmospheric attenuation, terrain obstruction, and geometric distortion during low elevation angle periods can be effectively eliminated, reducing the computational burden of subsequent processing. At the same time, it ensures that the solution of the maximum elevation angle is based solely on the second set of coordinate points, thereby accurately locking the satellite overhead time and its optimal observation angle, providing a reliable time and angle reference for subsequent space-based flight path design, and significantly improving the accuracy of space-air collaborative observation.

[0085] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6 As shown, the electronic device may include: a processor 610, a communications interface 620, a memory 630, and a communication bus 640, wherein the processor 610, the communications interface 620, and the memory 630 communicate with each other via the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute an observation route planning method, including: Based on the orbital information of the reference satellite and the position information of the observed target, the observation geometric angles at each moment during the transit of the reference satellite are determined; wherein, the observation geometric angles include the elevation angle and the azimuth angle. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, the route parameters for planning the observation route are determined, and the observation route is generated using the route parameters.

[0086] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0087] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer is able to execute the observation route planning method provided by the above methods, including: Based on the orbital information of the reference satellite and the position information of the observed target, the observation geometric angles at each moment during the transit of the reference satellite are determined; wherein, the observation geometric angles include the elevation angle and the azimuth angle. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, the route parameters for planning the observation route are determined, and the observation route is generated using the route parameters.

[0088] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the observation route planning methods provided by the above methods, including: Based on the orbital information of the reference satellite and the position information of the observed target, the observation geometric angles at each moment during the transit of the reference satellite are determined; wherein, the observation geometric angles include the elevation angle and the azimuth angle. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, the route parameters for planning the observation route are determined, and the observation route is generated using the route parameters.

[0089] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0090] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for planning observation routes, characterized in that, include: Based on the orbital information of the reference satellite and the position information of the observed target, the observation geometric angles at each moment during the transit of the reference satellite are determined; wherein, the observation geometric angles include the elevation angle and the azimuth angle. Determine the maximum elevation angle among the observed geometric angles, and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; Based on the elevation angle, azimuth angle, and observation resolution at the time of overpass, the route parameters for planning the observation route are determined, and the observation route is generated using the route parameters.

2. The observation route planning method as described in claim 1, characterized in that, The step of determining the observation geometry angle at each moment during the transit of the reference satellite, based on the orbital information of the reference satellite and the position information of the observation target, includes: Based on the orbital information of the reference satellite and the position information of the observed target, the local horizontal coordinates of the reference satellite relative to the observed target at each moment during its transit are calculated. Based on the local horizontal coordinates, the observed geometric angles at each moment during the transit period are calculated.

3. The observation route planning method as described in claim 1, characterized in that, Determining the maximum elevation angle in the observed geometric angles includes: A first coordinate point string with time reference is generated based on the observed geometric angle; The coordinate point string in the first coordinate point string whose elevation angle is greater than the preset elevation angle threshold is taken as the second coordinate point string; Iterate through the elevation angles of each coordinate point in the second coordinate point string, and determine the maximum elevation angle at each time point.

4. The observation route planning method as described in claim 1, characterized in that, The route parameters include route altitude, route azimuth, route start point, and route end point; The step of determining the route parameters for planning the observation route based on the elevation angle, azimuth angle, and observation resolution at the time of overpass includes: Determine the flight path altitude based on the observation resolution; Determine the azimuth of the flight path based on the azimuth at the time of the overhead crossing; Based on the altitude angle at the time of overhead passage and the flight path altitude, determine the horizontal displacement distance from the flight path to the observed target; The starting point and ending point of the route are determined based on the horizontal displacement distance.

5. The observation route planning method as described in claim 4, characterized in that, The step of determining the starting and ending points of the route based on the horizontal displacement distance includes: Determine the planar coordinates of the observed target; The perpendicular coordinates of the flight path are determined based on the plane coordinates, the horizontal displacement distance, and the reference rotation angle. The starting point and ending point of the route are determined based on the perpendicular coordinates of the route, the reference rotation angle, and the route length.

6. The observation route planning method as described in claim 5, characterized in that, The reference rotation angle is determined based on the azimuth angle of the flight path.

7. A device for observing flight path planning, characterized in that, include: The observation geometry angle determination module is used to determine the observation geometry angle at each moment during the transit of the reference satellite based on the orbital information of the reference satellite and the position information of the observation target; wherein, the observation geometry angle includes the elevation angle and the azimuth angle; The overpass time determination module is used to determine the maximum elevation angle in the observation geometry and determine the time corresponding to the maximum elevation angle as the overpass time of the reference satellite; The observation route planning module is used to determine the route parameters for planning the observation route based on the elevation angle, azimuth angle and observation resolution at the time of the overpass, and to generate the observation route using the route parameters.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the observation route planning method as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the observation route planning method as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the observation route planning method as described in any one of claims 1 to 6.

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