Method for judging sunlit area and shadow area in real time for remote sensing satellite in orbit

Abstract

The embodiment of the application discloses a method for judging the sunlit area and the shadow area of a remote sensing satellite in orbit in real time, and relates to the technical field of remote sensing satellites, which comprises the following steps: acquiring a first position vector of a remote sensing satellite in a geostationary system, acquiring a sunlight direction vector in the geostationary system; acquiring a second position vector of a projection point of the remote sensing satellite in the geostationary system; constructing a judgment vector based on the modulus of the first position vector relative to the second position vector, the reverse vector of the sunlight direction vector in the geostationary system and the position coordinates of a starting point; continuously iteratively calculating the height of the end point of each judgment vector, and judging whether the remote sensing satellite is located in the shadow area or the sunlit area according to the comparison result of the height and a preset threshold value. The embodiment of the application only needs a small number of iterations, can ensure the robustness of the calculation through iterative calculation, can stably and efficiently determine the area where the remote sensing satellite is located, can realize real-time in-orbit judgment, and can provide reliable data support for the pose adjustment of the satellite.

Description

Technical Field

[0001] The present application relates to the field of remote sensing satellite technology, and in particular to a method for real-time determination of sunlit areas and shadowed areas by a remote sensing satellite in orbit. Background Art

[0002] For high-precision optical remote sensing satellites, the payload is a high-resolution camera, and its optical and electronic components have certain operating temperature requirements. Therefore, camera temperature control is key to ensuring its normal operation.

[0003] During a satellite's in-orbit phase, the satellite's solar exposure changes due to changes in the geometric relationship between the satellite, Earth, and Sun. When the satellite maintains a heliocentric attitude, the camera's optical axis generally points away from the Sun. When the satellite is in the sunlit region, the heliocentric attitude points the camera's optical axis toward Earth; when the satellite is in the shadowed region, the heliocentric attitude points the camera's optical axis toward deep space. It's important to note that pointing the camera's optical axis toward deep space accelerates heat dissipation, making it impossible for the camera's temperature control system to maintain the camera within the operating range. Therefore, when the satellite is in the shadowed region, it is necessary to adjust from a heliocentric attitude to a geocentric attitude, pointing the camera's optical axis toward Earth to reduce heat loss.

[0004] Therefore, there is a need for a method that can efficiently and simply determine in real time whether a remote sensing satellite is located in a sunny area or a shadow area on orbit, so as to ensure that the satellite can adjust its attitude in time so that related components can work normally. Summary of the Invention

[0005] The present application provides a method for determining the sunlit and shadowed areas of a remote sensing satellite in real time while in orbit, to address the deficiencies in the above-mentioned related technologies. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for determining sunlit areas and shadowed areas in real time by a remote sensing satellite in orbit, comprising:

[0007] Obtaining the first position vector of the remote sensing satellite in the ground-fixed system and obtaining the sunlight direction vector of the ground-fixed system;

[0008] Taking the position of the remote sensing satellite as a starting point, projecting the starting point onto the ground to obtain a projection point, and obtaining a second position vector of the projection point on the ground fixed system;

[0009] Constructing a judgment vector: obtaining a modulus of a first position vector corresponding to the starting point relative to a second position vector, obtaining a reverse vector of the ground-fixed system sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector;

[0010] updating a position vector of the end point of the judgment vector at the ground-fixed system to obtain a new first position vector, calculating a height of the end point at the ground-fixed system based on the new first position vector, and comparing the height with a preset threshold;

[0011] If the height is less than the preset threshold, it is determined that the remote sensing satellite is located in a shadow area;

[0012] If the height is greater than or equal to the preset threshold, the number of projections is accumulated. If the number of projections is less than the threshold, the end point is updated to the next starting point, and the process jumps to the step of projecting the starting point to the ground to obtain the projection point. If the number of projections is greater than or equal to the threshold, it is determined that the remote sensing satellite is located in a sunny area.

[0013] In an optional solution of the first aspect, before obtaining the first position vector of the remote sensing satellite in the earth-fixed system and obtaining the sunlight direction vector of the earth-fixed system, the method further includes:

[0014] Obtain the current position information of the remote sensing satellite and the direction of sunlight;

[0015] Acquire a position vector of the remote sensing satellite in an inertial system based on the position information, and acquire a sunlight direction vector in an inertial system based on the sunlight direction information;

[0016] The position vector of the remote sensing satellite in the inertial system and the sunlight direction vector in the inertial system are converted to the earth-fixed system, and the first position vector and the earth-fixed system sunlight direction vector are output.

[0017] In an optional solution of the first aspect, converting the position vector of the remote sensing satellite in the inertial system and the inertial system sunlight direction vector to an earth-fixed system to obtain the first position vector and the earth-fixed system sunlight direction vector includes:

[0018] Obtaining a coordinate transformation matrix from the inertial system to the earth-fixed system;

[0019] The position vector of the remote sensing satellite in the inertial system is converted to the earth-fixed system based on the coordinate conversion matrix to obtain the first position vector, and the formula is applied:

[0020] R sat_ECF =M ECI2ECF ·R sat_ECI ;

[0021] The inertial system sunlight direction vector is converted to the earth-fixed system based on the coordinate transformation matrix to obtain the earth-fixed system sunlight direction vector, and the formula is applied:

[0022] r sun_ECF =M ECI2ECF ·rsun_ECI ;

[0023] Among them, ECI is the inertial system, ECF is the earth-fixed system, R sat_ECI is the position vector of the remote sensing satellite in the inertial system, M ECI2ECF is the coordinate transformation matrix, R sat_ECF is the first position vector, r sun_ECI is the sunlight direction vector of the inertial system, r sun_ECF is the direction vector of the sunlight on the ground.

[0024] In an optional solution of the first aspect, taking the position of the remote sensing satellite as a starting point, projecting the starting point onto the ground to obtain a projection point, and obtaining a second position vector of the projection point on a ground fixed system includes:

[0025] Obtaining the semi-major axis and the semi-minor axis of the Earth reference ellipsoid, converting the rectangular coordinates of the first position vector in the Earth-fixed system into longitude and latitude coordinates, and obtaining the longitude and latitude coordinates of the starting point;

[0026] The initial value of the altitude of the latitude and longitude coordinates of the starting point is:

[0027]

[0028] The initial latitude values ​​of the latitude and longitude coordinates of the starting point are:

[0029]

[0030] Calculate variable N1:

[0031]

[0032] Calculate the altitude, latitude and longitude of the starting point based on the variable N1 and the initial altitude value:

[0033]

[0034] L1=arctan(Y sat / X sat );

[0035] Output the latitude and longitude coordinates of the starting point:

[0036]

[0037] The longitude and latitude coordinates of the projection point are determined based on the longitude and latitude coordinates of the starting point, and the following is obtained:

[0038]

[0039] Calculate the variable N:

[0040]

[0041] Based on the variable N, the latitude and longitude coordinates of the projection point are converted into rectangular coordinates in the earth-fixed system to obtain the second position vector, and the formula is applied:

[0042]

[0043] Among them, a e is the semi-major axis of the Earth reference ellipsoid, b e is the minor axis of the earth reference ellipsoid, e is the eccentricity of the earth reference ellipsoid, H0 is the initial value of height, B0 is the initial value of latitude, H1 is height, B1 is latitude, L1 is longitude, R satn_ECF is the second position vector.

[0044] In an optional solution of the first aspect, after calculating the altitude, latitude, and longitude of the starting point, the method further includes:

[0045] Calculate the latitude difference from the initial latitude value:

[0046] dB = |B1-B0|;

[0047] Calculate the height difference between the initial height and the height:

[0048] dH=|H1-H0|;

[0049] Comparing the latitude difference with a preset latitude difference threshold, and comparing the height difference with a preset height difference threshold;

[0050] If both the latitude difference and the altitude difference are less than corresponding thresholds, the step of outputting the latitude and longitude coordinates of the starting point is performed;

[0051] Otherwise, the step of calculating the altitude, latitude and longitude of the starting point is performed, wherein dB is the latitude difference and dH is the altitude difference.

[0052] In a second aspect, an embodiment of the present application further provides a device for determining sunlit areas and shadowed areas in real time on a remote sensing satellite, comprising:

[0053] a data input module, configured to obtain a first position vector of the remote sensing satellite in the ground-fixed system, and further configured to obtain a sunlight direction vector of the ground-fixed system;

[0054] A projection module is configured to use the position of the remote sensing satellite as a starting point, project the starting point onto the ground to obtain a projection point, and obtain a second position vector of the projection point on the ground fixed system;

[0055] a judgment module, configured to construct a judgment vector by obtaining a modulus of the second position vector corresponding to the starting point relative to the third position vector, obtaining a reverse vector to the second sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector;

[0056] The judgment module is further configured to update the second position vector based on the end point of the judgment vector, calculate the height of the end point relative to the ground-fixed system based on the second position vector, and compare the height with a preset threshold;

[0057] If the height is less than the preset threshold, it is determined that the remote sensing satellite is located in a shadow area;

[0058] If the height is greater than or equal to the preset threshold, the number of projections is accumulated. If the number of projections is less than the threshold, the end point is updated to the next starting point, and the process jumps to the step of projecting the starting point to the ground to obtain the projection point. If the number of projections is greater than or equal to the threshold, it is determined that the remote sensing satellite is located in a sunny area.

[0059] In a third aspect, an embodiment of the present application further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method provided in the first aspect of the embodiment of the present application or any one of the implementations of the first aspect is implemented.

[0060] In a fourth aspect, the present application also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it implements the method provided by the first aspect of the embodiment of the present application or any one of the implementation methods of the first aspect.

[0061] The beneficial effects of the technical solutions provided by some embodiments of the present application include at least:

[0062] An embodiment of the present application provides a method for a remote sensing satellite to judge the sunlit area and the shadowed area in real time while in orbit. The method only requires the input of the orbital information of the remote sensing satellite at the current moment, and does not require other information uploaded by ground assistance. Multiple judgment vectors are calculated cyclically, and the height of the end point is determined each time based on the latitude and longitude coordinates of the end point of the judgment vector. Then, it is judged whether there is an intersection between the earth and a vector starting from the position coordinates of the remote sensing satellite and in the opposite direction of the sunlight direction vector of the earth-fixed system. If there is an intersection, it can be determined that the remote sensing satellite is located in the shadowed area, otherwise it is located in the sunlit area. The method provided in the embodiment of the present application only requires a small number of iterations. The robustness of the calculation can be ensured by iteratively calculating multiple judgment vectors, and the area where the remote sensing satellite is located can be determined stably and efficiently. It can also realize real-time on-orbit judgment, and can provide reliable data support for satellite posture adjustment based on the calculation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0064] Figure 1 This is a flow chart of a method for determining sunny and shadowed areas in real time on a remote sensing satellite in orbit, provided by an embodiment of the present application;

[0065] Figure 2 Schematic diagram of the relative position relationship of a method for determining the sunlit area and the shadowed area in real time on a remote sensing satellite in orbit provided by an embodiment of the present application;

[0066] Figure 3 This is a schematic diagram of the structure of a device for real-time determination of sunlit areas and shadowed areas of a remote sensing satellite in orbit, provided by an embodiment of the present application;

[0067] Figure 4 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0069] The terms "including" and "having," and any variations thereof, in the specification and claims of this application and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to the process, method, product, or apparatus.

[0070] It should be noted that the terms "first" and "second" used in this application are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that the terms "first" and "second" may interchangeably represent a specific order or precedence, where permitted. It should be understood that the objects distinguished by "first" and "second" may interchangeably represent a specific order or precedence, where appropriate, such that the embodiments of the present application described herein can be implemented in an order other than that described or illustrated herein.

[0071] The present application is described in detail below with reference to specific embodiments.

[0072] Next, combine Figure 1 , introduces a method for determining the sunlit area and shadowed area of ​​a remote sensing satellite in real time on orbit provided by an embodiment of the present application. Figure 2 , Figure 2 The flowchart of a method for determining the sunlit area and shadowed area of ​​a remote sensing satellite in real time on orbit provided by an embodiment of the present application is shown. Figure 1 As shown, the method includes the following steps:

[0073] S101, obtaining a first position vector of the remote sensing satellite in the ground-fixed system, and obtaining a sunlight direction vector of the ground-fixed system.

[0074] Taking the position of the remote sensing satellite as the starting point, perform the following steps:

[0075] S102: Project the starting point onto the ground to obtain a projection point, and obtain a second position vector of the projection point on the ground fixed system.

[0076] S103, constructing a judgment vector: obtaining the modulus of the first position vector corresponding to the starting point relative to the second position vector, obtaining the reverse vector of the ground-fixed system sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector.

[0077] S104 : obtaining a new first position vector based on the position vector of the end point of the judgment vector on the ground-fixed system, and calculating the height of the end point on the ground-fixed system based on the new first position vector.

[0078] S105: Compare the height with a preset threshold.

[0079] Furthermore, if the calculated height of the end point above the ground-fixed system is less than the preset threshold, it indicates that a vector starting from the position coordinates of the remote sensing satellite and directed in the opposite direction of the sunlight direction vector of the ground-fixed system intersects the Earth, and the following steps are performed:

[0080] S106: Determine whether the remote sensing satellite is located in the shadow area at the current moment.

[0081] Furthermore, if the calculated height of the end point above the ground anchor is greater than or equal to the preset threshold, the following steps are further performed:

[0082] S107, accumulating the number of projections and comparing the number of projections with a preset number threshold. If the number of projections is less than the number threshold, perform the following steps:

[0083] S108, update the end point to the next starting point, jump to S102, and execute S102 and subsequent steps;

[0084] If the projection times are greater than or equal to the times threshold, perform the following steps:

[0085] S109, determining whether the remote sensing satellite is located in the sunlight area at the current moment.

[0086] In some embodiments, before S101, the following steps are further included:

[0087] Obtain the current position information of the remote sensing satellite and the direction of sunlight;

[0088] Acquire a position vector of the remote sensing satellite in an inertial system based on the position information, and acquire a sunlight direction vector in an inertial system based on the sunlight direction information;

[0089] The position vector of the remote sensing satellite in the inertial system and the sunlight direction vector in the inertial system are converted to the earth-fixed system, and the first position vector and the earth-fixed system sunlight direction vector are output.

[0090] It can be understood that the position information of the remote sensing satellite at the corresponding moment can be determined by the satellite orbit information obtained in real time. Specifically, the vector of the inertial frame (Earth-Centered Inertial Frame, ECI) can be converted to the Earth-Centered Fixed Frame (ECF) through a preset coordinate transformation matrix, which specifically includes:

[0091] Obtaining a coordinate transformation matrix from the inertial system to the earth-fixed system;

[0092] The position vector of the remote sensing satellite in the inertial system is converted to the earth-fixed system based on the coordinate conversion matrix to obtain the first position vector, and the formula is applied:

[0093] R sat_ECF =M ECI2ECF ·R sat_ECI ;

[0094] The inertial system sunlight direction vector is converted to the earth-fixed system based on the coordinate transformation matrix to obtain the earth-fixed system sunlight direction vector, and the formula is applied:

[0095] r sun_ECF =M ECI2ECF ·r sun_ECI ;

[0096] Among them, ECI is the inertial system, ECF is the earth-fixed system, R sat_ECI is the position vector of the remote sensing satellite in the inertial system, M ECI2ECF is the coordinate transformation matrix, R sat_ECF is the first position vector, r sun_ECI is the sunlight direction vector of the inertial system, r sun_ECF is the direction vector of the sunlight on the ground.

[0097] In some embodiments, in S102, firstly, a position vector of a sub-satellite point of the remote sensing satellite on a ground fixed system, i.e., a second position vector, is determined;

[0098] Among them, the sub-satellite point of the remote sensing satellite can be understood as taking the position of the remote sensing satellite as the starting point, generating a line connecting the starting point and the center of the earth. The intersection of this line and the earth's surface is the sub-satellite point, that is, the projection point of the remote sensing satellite's position on the ground.

[0099] S102 specifically includes:

[0100] S1021: Obtain the semi-major axis and the semi-minor axis of the Earth reference ellipsoid, convert the rectangular coordinates of the first position vector in the Earth-fixed system into longitude and latitude coordinates, and obtain the longitude and latitude coordinates of the starting point.

[0101] The rectangular coordinates of the first position vector of the initial point in the ground-fixed system can be expressed as:

[0102]

[0103] The initial value of the altitude of the latitude and longitude coordinates of the starting point is:

[0104]

[0105] The initial latitude values ​​of the latitude and longitude coordinates of the starting point are:

[0106]

[0107] S1022, calculating variable N1, and calculating the altitude, latitude, and longitude of the starting point based on variable N1 and the initial altitude value, using the formula:

[0108]

[0109] L1=arctan(Y sat / X sat ).

[0110] S1023: Output the latitude and longitude coordinates of the starting point:

[0111]

[0112] S1024: Determine the latitude and longitude coordinates of the projection point based on the latitude and longitude coordinates of the starting point. Since the projection point is located on the ground, the height H needs to be set to 0.

[0113] Based on this, set the height value of the starting point to 0 to obtain the latitude and longitude coordinates LLA of the projection point satn_ECF :

[0114]

[0115] S1025, calculating a variable N, and converting the latitude and longitude coordinates of the projection point into rectangular coordinates in the ground-fixed system based on the variable N to obtain the second position vector, applying the formula:

[0116]

[0117] For any geographic longitude and latitude coordinates The formula can be applied:

[0118]

[0119] Since the height H of the projection point is set to 0, the second position vector obtained is as follows:

[0120]

[0121] Among them, a e is the semi-major axis of the Earth reference ellipsoid, b e is the minor axis of the earth reference ellipsoid, e is the eccentricity of the earth reference ellipsoid, H0 is the initial value of height, B0 is the initial value of latitude, H1 is height, B1 is latitude, L1 is longitude, R satn_ECF is the second position vector.

[0122] In some embodiments, after calculating the altitude, latitude, and longitude of the starting point at S1022, the latitude difference dB between the calculated latitude and the initial latitude value, and the height difference dH between the calculated altitude and the initial altitude value are further calculated using the following formula:

[0123] dB = |B1-B0|;

[0124] dH=|H1-H0|;

[0125] Comparing the latitude difference with a preset latitude difference threshold, and comparing the height difference with a preset height difference threshold;

[0126] If the latitude difference and the altitude difference are both less than the corresponding thresholds, executing step S1023 to output the latitude and longitude coordinates of the starting point;

[0127] Otherwise, execute step S1022 again.

[0128] In one embodiment, the following Figure 2 , introduces the specific calculation process of a method for real-time determination of sunlit areas and shadowed areas by a remote sensing satellite in orbit provided by an embodiment of the present application, such as Figure 2 The relative positions of the satellite, the Earth, and sunlight are shown in the figure, where S is the position of the satellite and T0 is the position of the sub-satellite point. The specific steps include:

[0129] S201, obtain the position vector R of the remote sensing satellite in the inertial system sat_ECI , get the sunlight direction vector r in the inertial system sun_ECI .

[0130] S202, applying the coordinate transformation matrix from the inertial system to the earth-fixed system, transforming the vector of the inertial system to the earth-fixed system:

[0131] R sat_ECF =M ECI2ECF ·R sat_ECI ;

[0132] r sun_EcF =M ECI2ECF ·r sun_ECI ;

[0133] Output the first position vector R of the remote sensing satellite on the ground sat_ECF and the ground-fixed sunlight direction vector r sun_ECF .

[0134] S203, obtain the major semi-axis a of the Earth reference ellipsoid e and the minor axis b e , the first position vector R under the ground fixed system sat_ECFThe rectangular coordinates are converted into longitude and latitude coordinates, and the position S of the remote sensing satellite is used as the starting point to obtain the longitude and latitude coordinates of the starting point. For details, please refer to the description of S1021-S1023, which will not be repeated here.

[0135] Furthermore, the projection point of the starting point on the ground is determined based on the position vector of the starting point. When the position S of the remote sensing satellite is the starting point, the obtained projection point, that is, the sub-satellite point is Figure 2 The second position vector R of point T0 on the ground fixed system can be determined based on S1024-S1025. T0_ECF ,Right now:

[0136] R T0_ECF =R satn_ECF ;

[0137] Among them, R satn_ECF That is, the position vector of the satellite's sub-satellite point on the ground fixed system.

[0138] It can be understood that the first position vector of the ground-fixed system can be regarded as Figure 2 The vector shown The intersection of the first position vector and the earth's surface is T0, and the second position vector is

[0139] S204, constructing a judgment vector, specifically including:

[0140] First determine the first position vector R sat_ECF Relative to the second position vector R T0_ECF Module R ST , apply the formula:

[0141] R ST =|R T0_ECF -R sat_ECF |;

[0142] Furthermore, taking the satellite position in the ground-fixed system as the starting point, the direction is selected as -r sun_ECF , the construction model is R ST Vector The details are as follows:

[0143]

[0144] Among them, T1 is the judgment vector The end point of T1 is located on a vector with the position coordinates of the remote sensing satellite as the starting point and the direction opposite to the direction of the sunlight vector of the earth-fixed system as the direction.

[0145] S205, based on the judgment vector The end point T1 is updated to obtain the new first position vector Application formula:

[0146]

[0147] Based on the new first position vector Execute steps S1021-S1023 to determine the longitude and latitude coordinates of point T1

[0148]

[0149] Then according to the longitude and latitude coordinates Get the height of point T1.

[0150] S206, compare the height of point T1 with a preset threshold, for example, the height threshold can be selected as 10 -6 .

[0151] Specifically, if the height of point T1 is less than a preset threshold, it indicates that a vector starting from the position coordinates of the remote sensing satellite and directed in the opposite direction of the direction of the sunlight vector of the earth-fixed system intersects the earth, and the following steps are performed:

[0152] S207: Determine whether the remote sensing satellite is located in the shadow area at the current moment.

[0153] Furthermore, if the height of point T1 is greater than or equal to the preset threshold, the following steps are further performed:

[0154] S208, cumulative projection times, let i=i+1

[0155] It should be noted that, before generating the sub-satellite point T0 of the satellite position S in S203, the initial projection number i=0 may be set.

[0156] The number of projections is compared with the preset number threshold. If the number of projections is less than the number threshold, for example, the number of projections i=1, the number threshold can be set to 20, and i is less than 20, then the following steps are performed:

[0157] S209: Update the end point T1 to the next starting point, jump to S203, and execute S203 and subsequent steps.

[0158] It can be understood that after T1 is updated to the next starting point, the projection point T′1 of T1 on the ground is further generated based on the first position vector corresponding to T1, and the second position vector obtained in step S203 is updated, that is, the rectangular coordinate of the position vector of T1′ in the ground fixed system is

[0159] Based on the rectangular coordinates of the position vector and A new judgment vector is constructed, and the virtual point T on the vector with the position coordinates of the remote sensing satellite as the starting point and the direction opposite to the direction of the sunlight of the ground fixed system as the direction is continuously calculated. i The longitude and latitude coordinates of the virtual point T i The coordinates of the remote sensing satellite are compared with the preset threshold value to determine whether the remote sensing satellite is in the sunlit area or the shadow area.

[0160] It should be noted that in S207, as long as the calculated height is less than the preset threshold, it indicates that a vector with the position coordinates of the remote sensing satellite as the starting point and the direction opposite to the direction of the sunlight vector of the earth-fixed system as the direction intersects the earth, and the judgment result that the satellite is in the shadow area can be directly output.

[0161] In S209, if the number of projections is less than the given number threshold, it is necessary to repeat S203 and subsequent steps, loop iterative calculation, and only when the number of projections is greater than or equal to the given number threshold, execute step S210:

[0162] S210, determining whether the remote sensing satellite is located in a sunny area at the current moment.

[0163] By continuously iterating in this way, it is possible to quickly and accurately determine whether the satellite is located in the sunlit area or the shadowed area, and to achieve real-time on-orbit judgment. No additional input information is required, only the satellite's on-orbit position and time are required. It has high robustness and real-time performance. Based on the judgment results, the satellite's posture can be adjusted in time to avoid defects such as excessive heat dissipation when the camera's optical axis points to deep space, which affects the working status of the satellite's components. This reduces heat consumption and ensures that the original components can work normally.

[0164] The following are device embodiments of the present application, which can be used to implement the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0165] See next Figure 3 , is a schematic diagram of the structure of a device for determining the sunlit and shadowed areas of a remote sensing satellite in orbit in real time, provided by an exemplary embodiment of the present application. The device can be implemented as all or part of a terminal through software, hardware, or a combination of both, and can also be integrated into a server as an independent module. The device for determining the sunlit and shadowed areas of a remote sensing satellite in orbit in real time in an embodiment of the present application can be applied to a terminal or the cloud. The device 30 includes a data input module 301, a projection module 302, and a judgment module 303, wherein:

[0166] The data input module 301 is used to obtain a first position vector of the remote sensing satellite in the ground-fixed system, and is also used to obtain a sunlight direction vector of the ground-fixed system;

[0167] The projection module 302 is configured to use the position of the remote sensing satellite as a starting point, project the starting point onto the ground to obtain a projection point, and obtain a second position vector of the projection point on the ground fixed system;

[0168] The judgment module 303 is configured to construct a judgment vector by obtaining a modulus of a first position vector corresponding to the starting point relative to a second position vector, obtaining a reverse vector of the ground-fixed system sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector.

[0169] The judgment module 303 is further configured to update a new first position vector based on the position vector of the end point of the judgment vector on the ground-fixed system, calculate the height of the end point on the ground-fixed system based on the new first position vector, and compare the height with a preset threshold;

[0170] If the height is less than the preset threshold, it is determined that the remote sensing satellite is located in a shadow area;

[0171] If the height is greater than or equal to the preset threshold, the number of projections is accumulated. If the number of projections is less than the threshold, the end point is updated to the next starting point, and the process jumps to the step of projecting the starting point to the ground to obtain the projection point. If the number of projections is greater than or equal to the threshold, it is determined that the remote sensing satellite is located in a sunny area.

[0172] It should be noted that the device 30 provided in the above embodiment, when executing a method for determining sunlit and shadowed areas in real time while a remote sensing satellite is in orbit, only uses the division of the above-mentioned functional modules as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the device provided in the above embodiment and the embodiment of the method for determining sunlit and shadowed areas in real time while a remote sensing satellite is in orbit are based on the same concept. The implementation process is detailed in the method embodiment and will not be repeated here.

[0173] An embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method of any of the above embodiments are implemented.

[0174] See Figure 4 , is a structural block diagram of an electronic device provided in an embodiment of the present application.

[0175] like Figure 4 As shown, the electronic device 400 includes a processor 401 and a memory 402 .

[0176] In the embodiment of the present application, the processor 401 is the control center of the computer system and can be the processor of a physical machine or the processor of a virtual machine. The processor 401 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 401 can be implemented in the form of at least one hardware selected from the group consisting of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array).

[0177] The processor 401 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also called a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0178] The memory 402 may include one or more computer-readable storage media, which may be non-transitory. The memory 402 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash memory storage devices. In some embodiments of the present application, the non-transitory computer-readable storage medium in the memory 402 is used to store at least one instruction, which is used to be executed by the processor 401 to implement the method in the embodiment of the present application.

[0179] In some embodiments, the electronic device 400 further includes: a peripheral device interface 403 and at least one peripheral device 404. The processor 401, the memory 402, and the peripheral device interface 403 can be connected via a bus or signal lines. Each peripheral device 404 can be connected to the peripheral device interface 403 via a bus, signal lines, or a circuit board. Specifically, the peripheral devices 404 include: a display screen, a camera, and an audio circuit. The peripheral device interface 403 can be used to connect at least one I / O (Input / Output)-related peripheral device to the processor 401 and the memory 402.

[0180] In some embodiments of the present application, the processor 401, the memory 402, and the peripheral device interface 403 are integrated on the same chip or circuit board; in some other embodiments of the present application, any one or two of the processor 401, the memory 402, and the peripheral device interface 403 may be implemented on separate chips or circuit boards. This embodiment of the present application is not specifically limited to this.

[0181] The electronic device structure block diagram shown in the embodiment of the present application does not constitute a limitation on the electronic device 400. The electronic device 400 may include more or fewer components than shown in the figure, or combine certain components, or adopt a different component arrangement.

[0182] The present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method of any of the aforementioned embodiments. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a microdrive, a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0183] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the sunlit area and shadowed area in real time by a remote sensing satellite on orbit, characterized in that: include: Obtaining the first position vector of the remote sensing satellite in the ground-fixed system and obtaining the sunlight direction vector of the ground-fixed system; Taking the position of the remote sensing satellite as a starting point, projecting the starting point onto the ground to obtain a projection point, and obtaining a second position vector of the projection point on the ground fixed system; Constructing a judgment vector: obtaining a modulus of a first position vector corresponding to the starting point relative to a second position vector, obtaining a reverse vector of the ground-fixed system sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector; updating a position vector of the end point of the judgment vector at the ground-fixed system to obtain a new first position vector, calculating a height of the end point at the ground-fixed system based on the new first position vector, and comparing the height with a preset threshold; If the height is less than the preset threshold, it is determined that the remote sensing satellite is located in a shadow area; If the height is greater than or equal to the preset threshold, the number of projections is accumulated. If the number of projections is less than the threshold, the end point is updated to the next starting point, and the process jumps to the step of projecting the starting point to the ground to obtain the projection point. If the number of projections is greater than or equal to the threshold, it is determined that the remote sensing satellite is located in a sunny area.

2. The method for determining the sunlit area and shadowed area in real time by a remote sensing satellite on orbit according to claim 1, characterized in that: Before obtaining the first position vector of the remote sensing satellite in the ground-fixed system and obtaining the sunlight direction vector of the ground-fixed system, the method further includes: Obtain the current position information of the remote sensing satellite and the direction of sunlight; Acquire a position vector of the remote sensing satellite in an inertial system based on the position information, and acquire a sunlight direction vector in an inertial system based on the sunlight direction information; The position vector of the remote sensing satellite in the inertial system and the sunlight direction vector in the inertial system are converted to the earth-fixed system, and the first position vector and the earth-fixed system sunlight direction vector are output.

3. The method for determining the sunlit area and shadowed area in real time by a remote sensing satellite in orbit according to claim 2, characterized in that: The converting the position vector of the remote sensing satellite in the inertial system and the sunlight direction vector in the inertial system to the earth-fixed system to obtain the first position vector and the sunlight direction vector in the earth-fixed system includes: Obtaining a coordinate transformation matrix from the inertial system to the earth-fixed system; The position vector of the remote sensing satellite in the inertial system is converted to the earth-fixed system based on the coordinate conversion matrix to obtain the first position vector, and the formula is applied: R sat_ECF =M ECI2ECF ·R sat_ECI ; The inertial system sunlight direction vector is converted to the earth-fixed system based on the coordinate transformation matrix to obtain the earth-fixed system sunlight direction vector, and the formula is applied: r sun_ECF ＝M ECI2ECF ·r sun_ECI ； Among them, ECI is the inertial system, ECF is the earth-fixed system, R sat_ECI is the position vector of the remote sensing satellite in the inertial system, M ECI2ECF is the coordinate transformation matrix, R sat_ECF is the first position vector, r sun_ECI is the sunlight direction vector of the inertial system, r sun_ECF is the direction vector of the sunlight on the ground.

4. The method for determining the sunlit area and shadowed area in real time by a remote sensing satellite on orbit according to claim 3, characterized in that: The method of taking the position of the remote sensing satellite as a starting point, projecting the starting point onto the ground to obtain a projection point, and obtaining a second position vector of the projection point on the ground fixed system includes: Obtaining the semi-major axis and the semi-minor axis of the Earth reference ellipsoid, converting the rectangular coordinates of the first position vector in the Earth-fixed system into longitude and latitude coordinates, and obtaining the longitude and latitude coordinates of the starting point; The initial value of the altitude of the latitude and longitude coordinates of the starting point is: The initial latitude values ​​of the latitude and longitude coordinates of the starting point are: Calculate variable N1: Calculate the altitude, latitude and longitude of the starting point based on the variable N1 and the initial altitude value: L1=arctan(Y sat / X sat ); Output the latitude and longitude coordinates of the starting point: The longitude and latitude coordinates of the projection point are determined based on the longitude and latitude coordinates of the starting point, and the following is obtained: Calculate the variable N: Based on the variable N, the latitude and longitude coordinates of the projection point are converted into rectangular coordinates in the earth-fixed system to obtain the second position vector, and the formula is applied: Among them, a e is the semi-major axis of the Earth reference ellipsoid, b e is the minor axis of the earth reference ellipsoid, e is the eccentricity of the earth reference ellipsoid, H0 is the initial value of height, B0 is the initial value of latitude, H1 is height, B1 is latitude, L1 is longitude, R satn_ECF is the second position vector.

5. The method for determining the sunlit area and shadowed area in real time by a remote sensing satellite on orbit according to claim 4, characterized in that: After calculating the altitude, latitude and longitude of the starting point, the method further includes: Calculate the latitude difference from the initial latitude value: dB = |B1-B0|; Calculate the height difference between the initial height and the height: dH=|H1-H0|; Comparing the latitude difference with a preset latitude difference threshold, and comparing the height difference with a preset height difference threshold; If the latitude difference and the altitude difference are both less than corresponding thresholds, then executing the step of outputting the latitude and longitude coordinates of the starting point; Otherwise, executing the step of calculating the altitude, latitude and longitude of the starting point; Wherein, dB is the latitude difference, and dH is the height difference.

6. A device for determining the sunlit and shadowed areas of a remote sensing satellite in real time on orbit, characterized in that: include: A data input module is used to obtain a first position vector of the remote sensing satellite on the ground-fixed system and also to obtain a sunlight direction vector of the ground-fixed system; A projection module is configured to use the position of the remote sensing satellite as a starting point, project the starting point onto the ground to obtain a projection point, and obtain a second position vector of the projection point on the ground fixed system; a judgment module, configured to construct a judgment vector by obtaining a modulus of a first position vector corresponding to the starting point relative to a second position vector, obtaining a reverse vector of the ground-fixed system sunlight direction vector, and constructing a judgment vector based on the position coordinates of the starting point, the modulus, and the reverse vector; The judgment module is further configured to update a new first position vector based on the position vector of the end point of the judgment vector on the ground-fixed system, calculate the height of the end point on the ground-fixed system based on the new first position vector, and compare the height with a preset threshold; If the height is less than the preset threshold, it is determined that the remote sensing satellite is located in a shadow area; If the height is greater than or equal to the preset threshold, the number of projections is accumulated. If the number of projections is less than the threshold, the end point is updated to the next starting point, and the process jumps to the step of projecting the starting point to the ground to obtain the projection point. If the number of projections is greater than or equal to the threshold, it is determined that the remote sensing satellite is located in a sunny area.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 5 are implemented.

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

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