Sun-synchronous orbit satellite imaging probability analysis method based on illumination constraint

Abstract

The invention provides an illumination constraint-based sun-synchronous orbit satellite imaging probability analysis method, which comprises the following steps of: determining an orbit height and a latitude argument under a set time interval in an orbit period of a satellite; determining the geographic latitude, the latitude argument and the orbit height of the sub-satellite point of the satellite at each position of the orbit descending section; determining a geocentric field angle of the satellite at each position pointing edge projection point and a sub-satellite point in the orbit descending section; determining whether the to-be-analyzed latitude with the visible light imaging condition points to the position of the edge projection point or not in the orbit descending section of the satellite; determining the local time of the boundary line position after the solar altitude constraint is considered; comparing whether the latitude of the to-be-analyzed satellite with the visible light imaging condition points to the position of the edge projection point in the orbit descending section, and considering the local position of the boundary line position after solar altitude constraint, judging whether the visible light imaging condition is met, traversing the time of one year and the related latitude, and carrying out statistics to obtain the visible light imaging probability of the satellite.

Description

Technical Field

[0001] The present invention belongs to the field of satellite imaging probability analysis, and in particular relates to a sun-synchronous orbit satellite imaging probability analysis method based on illumination constraints, which is applicable to an optical remote sensing satellite for earth imaging using a low-orbit sun-synchronous orbit. Background Art

[0002] Sun-synchronous orbits are widely used in optical remote sensing satellites for earth imaging because the relative relationship between the orbital plane and the incident direction of sunlight is relatively fixed, and its lighting conditions are more stable. However, in the earth imaging mission of optical remote sensing satellites, the visible spectrum is greatly affected by lighting conditions. Too low solar altitude angles will result in insufficient light intensity, and the quality of the acquired images is difficult to meet application requirements. In addition, due to the influence of the earth's rotation and revolution, the relative position of the sun and the earth is constantly changing, and the solar altitude angles of ground targets at different latitudes are also constantly changing. There is also uncertainty as to whether satellites can be used for visible light imaging.

[0003] At present, STK (Satellite Toolbox) software is usually used to analyze the revisit coverage capability of sun-synchronous orbit satellites for ground targets at different solar altitude angle thresholds. By exporting the solar altitude angle data of sub-satellite points at different latitudes within a year and comparing the size with the given solar altitude angle threshold, it is determined whether the conditions for visible light imaging are met. However, this method can only image sub-satellite points (satellite roll angle and pitch angle are both 0°), and the probability of the target appearing near the sub-satellite point when the optical remote sensing satellite is actually imaging the earth in orbit is extremely low, and frequent attitude maneuvers are required. It is impossible to determine whether the lighting conditions of the ground target pointed to by the satellite at different roll / pitch combination angles meet the application requirements. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the inventors have conducted intensive research and provided a method for analyzing the imaging probability of sun-synchronous orbit satellites based on illumination constraints, which solves the problem that the imaging probability of sub-satellite point targets can only be directly analyzed, but the imaging probability of the target point after attitude maneuvers cannot be directly analyzed.

[0005] The technical solution provided by the present invention is as follows:

[0006] In a first aspect, a probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints comprises:

[0007] Determine the orbital altitude and latitude argument of the satellite within one orbital cycle and at a set time interval based on the apogee altitude, perigee altitude and perigee argument of the sun-synchronous orbit;

[0008] According to the satellite orbit inclination, as well as the orbit altitude and latitude argument at a set time interval within one orbital cycle of the satellite, the geographic latitude, latitude argument and orbit altitude of the sub-satellite point at each position of the satellite in the descending orbit segment during visible light imaging are determined;

[0009] According to the satellite's maximum lateral swing angle capability and the satellite's orbital altitude at each position in the descending orbit segment, the geocentric angle between the satellite's edge projection point and the sub-satellite point at each position in the descending orbit segment is determined;

[0010] According to the local time of the satellite descending node, the satellite orbit inclination, the geocentric angle between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment, the latitude argument of each position of the satellite in the descending orbit segment and the geographical latitude of the sub-satellite point, determine the local time of the edge projection point at the latitude to be analyzed for whether the satellite has the visible light imaging condition in the descending orbit segment;

[0011] When determining the local location of the boundary line after considering the sun altitude angle constraint;

[0012] By comparing the relationship between the local time of the edge projection point at the latitude to be analyzed for visible light imaging conditions in the descending orbit segment and the local local time of the boundary line position after considering the solar altitude angle constraint, it is determined whether the conditions for visible light imaging are met. The probability of satellite visible light imaging is statistically obtained by traversing the time of one year and the relevant latitudes.

[0013] In a second aspect, a sun-synchronous orbit satellite imaging probability analysis device based on illumination constraints comprises:

[0014] one or more processors;

[0015] a storage device for storing one or more programs,

[0016] When the one or more programs are executed by the one or more processors, the one or more processors implement the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0017] In a third aspect, a readable storage medium stores a computer program, which, when executed by a processor, implements the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0018] In a fourth aspect, a computer program product is provided, comprising: a computer program (also referred to as code, or instruction), which, when executed, executes the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0019] A method for analyzing the probability of sun-synchronous orbit satellite imaging based on illumination constraints provided by the present invention has the following beneficial effects:

[0020] The present invention provides a method for analyzing the imaging probability of a sun-synchronous orbit satellite based on illumination constraints. The method is based on the mathematical theoretical derivation of a simplified spherical earth model, and traverses the imaging probabilities of ground targets at different solar altitude constraints, different maximum swing angle capabilities, and different latitudes. It can effectively guide users in planning and formulating imaging tasks, and solves the problem that STK simulation can only directly analyze the imaging probability of sub-satellite point targets, but cannot directly analyze the imaging probability of a target point after attitude maneuvering. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flow chart of the probability analysis method of sun-synchronous orbit satellite imaging based on illumination constraints. DETAILED DESCRIPTION

[0022] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0023] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0024] Figure 1 The implementation process of the probability analysis method of sun-synchronous orbit satellite imaging based on illumination constraints of the present invention is as follows.

[0025] 1. Based on the apogee altitude, perigee altitude and perigee argument of the sun-synchronous orbit, determine the orbital altitude and latitude argument of the satellite within one orbital period and at a set time interval.

[0026] (1) According to the apogee height r of the sun-synchronous orbit a (unit km), perigee height r p (unit km), Earth's gravitational constant μ (398600.44 km 3 / s 2 ), the average radius of the Earth R E (6371km), determine the semi-major axis a (in km), focal length c (in km), eccentricity e (dimensionless), semi-diameter p (in km), angular momentum h (in km 2 / s), average angular velocity n (unit: rad / s), and orbital period T (unit: s).

[0027] a=R E +(r a +r p )2(1)

[0028] c=(r a -r p)2(2)

[0029] e=ca(3)

[0030] p=a(1-e 2 )(4)

[0031]

[0032] T=2π / n(7)

[0033] (2) Based on the average angular velocity n (in rad / s), determine the mean anomaly M (in rad) at each time t (in s) at an interval of Δt (in s) within one orbital period.

[0034] t=0:Δt:T(8)

[0035] M=nt(9)

[0036] (3) Based on the mean anomaly M (in rad) and the eccentricity e (dimensionless) at each time t (in s), an iterative method is used to determine the eccentric anomaly E (in rad) at a set time interval within an orbital period.

[0037] E i+1 =M+esinE i (10)

[0038] The initial value of the iteration is set to E0 = M. The precision ε (in rad) can be any value with high precision. i+1 -E i When <ε, the iteration ends and E=E i+1 .

[0039] (4) Based on the eccentric anomaly E (unit: rad) and the eccentricity e (dimensionless) within one orbital period and at a set time interval, determine the true anomaly f (unit: rad) within one orbital period and at a set time interval.

[0040]

[0041] (5) According to the angular momentum h (unit: km 2 / s), Earth's gravitational constant μ(398600.44km 3 / s 2 ), eccentricity e (dimensionless), true anomaly f (unit rad), mean radius of the Earth R E (6371km), determine the distance r (in km) from the center of the Earth and the orbital height H (in km) at a set time interval within an orbital period.

[0042]

[0043] H=rR E (13)

[0044] (6) Based on the argument of perigee ω (unit: rad) and the true anomaly f (unit: rad), determine the argument of latitude θ (unit: rad) within one orbital period and at a set time interval.

[0045] θ=ω+f(14)

[0046] 2. Determine the geographic latitude, latitude argument and orbital altitude of the sub-satellite point at each position in the descending orbit segment during visible light imaging based on the satellite orbit inclination, as well as the orbital altitude and latitude argument at set time intervals within one orbital period of the satellite.

[0047] (1) Determine the geographic latitude of the sub-satellite point within an orbital period and at a set time interval based on the orbital inclination i (in rad) and the latitude argument θ (in rad) (Unit: rad).

[0048]

[0049] (2) Based on the geographical latitude of the sub-satellite point at a set time interval within an orbital period (Unit: rad), determines the position number of the maximum and minimum geographical latitude of the sub-satellite point.

[0050] Determine the position number corresponding to the maximum geographical latitude of the sub-satellite point satisfy:

[0051]

[0052] Determine the position number corresponding to the minimum geographical latitude of the sub-satellite point satisfy:

[0053]

[0054] (3) Based on the position numbers of the maximum and minimum geographical latitudes of the sub-satellite point, determine the position number range of the descending orbit segment from the maximum to the minimum geographical latitude of the sub-satellite point.

[0055]

[0056] (4) According to the position number range of the descending orbit segment from the largest to the smallest geographical latitude of the sub-satellite point, and the geographical latitude of the sub-satellite point at a set time interval within an orbital cycle (unit: rad), latitude angle θ (unit: rad), orbit height H (unit: km), determine the geographic latitude of the sub-satellite point at each position of the satellite in the descending orbit during visible light imaging (unit: rad), latitude angle θ descend(unit: rad), orbit height H descend (Unit: km).

[0057]

[0058] θ descend =θ(I ndex_descend )(20)

[0059] H descend =H(I ndex_descend )(twenty one)

[0060] 3. Based on the satellite's maximum lateral swing angle capability and the satellite's orbital height H at each position in the descending orbit segment descend (Unit: km), determine the geocentric angle between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment.

[0061] (1) According to the orbital height H of the satellite at each position in the descending orbit segment descend (Unit: km), determine the maximum allowable side swing angle α of the satellite at each position in the descending orbit segment max_allowed (Unit: rad).

[0062]

[0063] (2) Based on the satellite's maximum roll angle capability α max (unit: rad), determine the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use (Unit: rad).

[0064]

[0065] (3) According to the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use (unit: rad) and the orbit height H at each position of the descending orbit segment descend (Unit: km), determine the elevation angle E of the ground observation point pointing to the edge of the satellite at each position in the descending orbit segment lev (Unit: rad).

[0066]

[0067] (4) Based on the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use (unit: rad), elevation angle E of the ground observation point pointing to the edge lev (unit: rad), determine the geocentric angle β (unit: rad) between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment.

[0068]

[0069] 4. Based on the local time of the satellite descending node, the satellite orbit inclination, the geocentric angle β (unit: rad) between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit, and the latitude angle θ of the satellite at each position of the satellite in the descending orbit descend (unit: rad) and the geographic latitude of the sub-satellite point (Unit: rad), when the latitude of the satellite to be analyzed in the descending orbit segment to determine whether it has the visible light imaging conditions points to the edge projection point.

[0070] (1) According to the descending node local time L T_descend (unit: h), orbital inclination i (unit: rad), latitude argument θ of the satellite at each position in the descending orbit segment descend (unit: rad), determine the sub-satellite local time L at each position of the satellite in the descending orbit segment T_Lat_sat (Unit: h).

[0071]

[0072] (2) Find the latitude L to be analyzed to see if it has the conditions for visible light imaging at_sat (Unit: rad) Geographic latitude of the sub-satellite point in the descending orbit (unit rad) Position number I ndex_Lat_sat ,satisfy:

[0073]

[0074] And determine the longitude difference L between the edge projection point and the subsatellite point at this location ONG_diff (Unit: rad).

[0075]

[0076] (3) Determine the latitude L of the satellite in the descending orbit segment to be analyzed to see whether it has the conditions for visible light imaging. at_sat The local time L of the westernmost (morning orbit) or easternmost (afternoon orbit) ground pointing point at the same latitude (unit: rad) T_edge (Unit: h).

[0077]

[0078] 5. Determine the local time of the boundary line position after considering the solar altitude angle constraint.

[0079] (1) Determine the solar declination δ based on the number of days N from the vernal equinox. S (Unit: rad).

[0080]

[0081] (2) According to the solar declination δ S(unit: rad), determine the angle B (unit: rad) between the Earth's terminator plane and the equatorial plane.

[0082]

[0083] (3) According to the solar altitude angle threshold value θ h_TH (unit rad) and the angle B (unit rad) between the Earth's twilight plane and the equatorial plane, determine the geographical latitude L of the boundary line between the northern hemisphere and the southern hemisphere corresponding to 12 noon at_NorthB , L at_SouthB (Unit: rad).

[0084] L at_NorthB_temp =B+θ h_TH (33)

[0085]

[0086] L at_SouthB_temp =B-θ h_TH -180(35)

[0087]

[0088] (4) Based on whether the latitude L to be analyzed has visible light imaging conditions at_sat (unit: rad), determine the solar altitude angle at this latitude as the solar altitude angle threshold value θ h_TH (unit: rad) The local time L on the west side of the boundary line (in the morning) corresponding to the time T_TH_forenoon (unit: h), local time L on the east side (afternoon) T_TH_afternoon (Unit: h).

[0089] Divide into the following 4 cases to solve whether the latitude L to be analyzed has the conditions for visible light imaging at_sat (unit rad), the solar altitude angle is the solar altitude angle threshold value θ h_TH The longitude difference L between the boundary line position at 12 o'clock (unit: rad) and the position at noon ON_theta_h_TH (Unit: rad).

[0090] When δ S ≥0 and θ h_TH <δ S hour:

[0091]

[0092] When δ S ≥0 and θ h_TH ≥δ S hour:

[0093]

[0094] When δ S <0 and θ h_TH <-δ S hour:

[0095]

[0096] When δ S <0 and θ h_TH ≥-δ S hour:

[0097]

[0098] Determine whether the latitude L to be analyzed has visible light imaging conditions at_sat (unit rad), the solar altitude angle is the solar altitude angle threshold value θ h_TH (unit: rad) The local time L on the west side of the boundary line corresponding to the location T_TH_forenoon , local time on the east side T_TH_afternoon (Unit: h).

[0099]

[0100]

[0101] 6. Compare the relationship between the latitude of the satellite in the descending orbit segment to determine whether it has the conditions for visible light imaging and the local time of the edge projection point and the local time of the boundary line after considering the solar altitude angle constraint, and determine whether it has the conditions for visible light imaging (visible light at L T_TH_forenoon ≤L T_edge ≤L T_TH_afternoon The satellite visible light imaging probability P is obtained by traversing the time of one year and the relevant latitudes. cam (Unit: %) The satellite’s visible light imaging probability P cam It can be expressed by the probability of the number of days with visible light imaging conditions at each latitude throughout the year, or by the weighted average of the probabilities of the number of days with visible light imaging conditions at each latitude throughout the year.

[0102] The present invention also provides a sun-synchronous orbit satellite imaging probability analysis device based on illumination constraints, comprising:

[0103] one or more processors;

[0104] A storage device for storing one or more programs;

[0105] When the one or more programs are executed by the one or more processors, the one or more processors implement the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0106] The present invention also provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0107] The readable storage medium includes, but is not limited to, various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0108] The present invention also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which, when executed, executes the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints described in the first aspect.

[0109] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, microwave, etc.) mode to another website site, computer, server or data center.

[0110] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0111] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device and product can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0112] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0113] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints, characterized in that: include: Determine the orbital altitude and latitude argument of the satellite within one orbital cycle and at a set time interval based on the apogee altitude, perigee altitude and perigee argument of the sun-synchronous orbit; According to the satellite orbit inclination, as well as the orbit altitude and latitude argument at a set time interval within one orbital cycle of the satellite, the geographic latitude, latitude argument and orbit altitude of the sub-satellite point at each position of the satellite in the descending orbit segment during visible light imaging are determined; According to the satellite's maximum lateral swing angle capability and the satellite's orbital altitude at each position in the descending orbit segment, the geocentric angle between the satellite's edge projection point and the sub-satellite point at each position in the descending orbit segment is determined; According to the local time of the satellite descending node, the satellite orbit inclination, the geocentric angle between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment, the latitude argument of each position of the satellite in the descending orbit segment and the geographical latitude of the sub-satellite point, determine the local time of the edge projection point at the latitude to be analyzed for whether the satellite has the visible light imaging condition in the descending orbit segment; When determining the local location of the boundary line after considering the sun altitude angle constraint; By comparing the relationship between the local time of the edge projection point at the latitude to be analyzed for visible light imaging conditions in the descending orbit segment and the local local time of the boundary line position after considering the solar altitude angle constraint, it is determined whether the conditions for visible light imaging are met. The probability of satellite visible light imaging is statistically obtained by traversing the time of one year and the relevant latitudes.

2. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The steps of determining the orbital altitude and latitude argument of the satellite within one orbital cycle and at a set time interval according to the apogee altitude, perigee altitude and perigee argument of the sun-synchronous orbit include: Determine the eccentricity, semi-diameter, angular momentum, average angular velocity and orbital period based on the apogee altitude, perigee altitude, gravitational constant and mean radius of the sun-synchronous orbit; Based on the average angular velocity, determine the mean anomaly angle within an orbital period and at a set time interval; According to the mean anomaly and the eccentricity within one orbital period and at a set time interval, an iterative method is used to determine the eccentric anomaly within one orbital period and at a set time interval; Determine the true anomaly within one orbital period and at a set time interval based on the eccentric anomaly and the eccentricity within one orbital period and at a set time interval; Determine the distance from the center of the Earth and the orbital altitude within an orbital period and at a set time interval based on the momentum, the Earth's gravitational constant, the eccentricity, the true anomaly and the mean radius of the Earth; Based on the perigee argument and the true anomaly at a set time interval within an orbital period, the latitude argument within an orbital period and a set time interval is determined.

3. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The step of determining the geographic latitude, latitude argument and orbital altitude of the sub-satellite point at each position of the satellite in the descending orbit segment during visible light imaging according to the satellite orbit inclination, and the orbital altitude and latitude argument at a set time interval within one orbital cycle of the satellite includes: (1) Determine the geographic latitude of the sub-satellite point within an orbital period and at a set time interval based on the orbital inclination i and the latitude argument θ (2) Based on the geographical latitude of the sub-satellite point at a set time interval within an orbital period Determine the position number of the maximum and minimum geographical latitude of the sub-satellite point; Determine the position number corresponding to the maximum geographical latitude of the sub-satellite point satisfy: Determine the position number corresponding to the minimum geographical latitude of the sub-satellite point satisfy: (3) According to the position numbers of the maximum and minimum geographical latitudes of the sub-satellite point, determine the position number range of the descending orbit segment from the maximum to the minimum geographical latitude of the sub-satellite point; (4) According to the position number range of the descending orbit segment from the largest to the smallest geographical latitude of the sub-satellite point, and the geographical latitude of the sub-satellite point at a set time interval within an orbital cycle The latitude angle θ and orbit height H determine the geographic latitude of the sub-satellite point at each position of the satellite in the descending orbit during visible light imaging. Latitude Argument θ descend 、Track height H descend ; i descend =θ(I ndex_descend ) H descend =H(I ndex_descend )。 4. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The step of determining the geocentric angle between the projection point pointing to the edge and the sub-satellite point at each position of the satellite in the descending orbit segment according to the maximum roll angle capability of the satellite and the orbital height of each position of the satellite in the descending orbit segment comprises: (1) According to the orbital height H of the satellite at each position in the descending orbit segment descend , determine the maximum allowable side swing angle α of the satellite at each position in the descending orbit segment max_allowed ; (2) Based on the satellite's maximum roll angle capability α max , determine the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use ; (3) According to the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use and the track height H at each position of the descending track segment descend , determine the elevation angle E of the ground observation point pointing to the edge of the satellite at each position in the descending orbit segment lev ; (4) Based on the maximum side swing angle α actually used by the satellite at each position in the descending orbit segment max_use , the elevation angle E of the ground observation point pointing to the edge lev , determine the geocentric angle β between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment; 5. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The step of determining the time when the latitude of the satellite to be analyzed in the descending orbit segment for whether the visible light imaging condition is met points to the edge projection point based on the local time of the satellite descending node, the satellite orbit inclination, the geocentric angle between the edge projection point and the sub-satellite point at each position of the satellite in the descending orbit segment, the latitude argument of each position of the satellite in the descending orbit segment, and the geographical latitude of the sub-satellite point, comprises: (1) According to the descending node local time L T_descend , orbit inclination i, latitude argument θ of the satellite at each position in the descending orbit segment descend , determine the sub-satellite local time L at each position of the satellite in the descending orbit segment T_Lat_sat ; (2) Find the latitude L to be analyzed to see if it has the conditions for visible light imaging at_sat Geographic latitude of the subsatellite point in the descending orbit Position number I ndex_Lat_sat ,satisfy: And determine the longitude difference L between the edge projection point and the subsatellite point at this location ONG_diff ; (3) Determine the latitude L of the satellite in the descending orbit segment to be analyzed to see whether it has the conditions for visible light imaging. at_sat The westernmost or easternmost ground point at the same latitude L T_edge ; 6. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The step of determining the local time of the boundary line position after considering the sun altitude angle constraint comprises: (1) Determine the solar declination δ based on the number of days N from the vernal equinox. S ; (2) According to the solar declination δ S , determine the angle B between the Earth's twilight line plane and the equatorial plane; (3) According to the solar altitude angle threshold value θ h_TH The angle B between the Earth's twilight plane and the equatorial plane determines the geographical latitude L of the boundary between the northern and southern hemispheres corresponding to 12 noon. at_NorthB , L at_SouthB ; L at_NorthB_temp =B+θ h_TH L at_SouthB_temp =B-θ h_TH -180 (4) Based on whether the latitude L to be analyzed has visible light imaging conditions at_sat , determine the solar altitude angle at this latitude as the solar altitude angle threshold value θ h_TH The local time L on the west side of the border line corresponding to the time T_TH_forenoon , local time on the east side T_TH_afternoon .

7. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 6, characterized in that: The latitude L to be analyzed based on whether the conditions for visible light imaging are met at_sat , determine the solar altitude angle at this latitude as the solar altitude angle threshold value θ h_TH The local time L on the west side of the border line corresponding to the time T_TH_forenoon , local time on the east side T_TH_afternoon The steps include: Determine whether the latitude L to be analyzed meets the conditions for visible light imaging according to the situation at_sat The solar altitude angle is the solar altitude angle threshold value θ h_TH The longitude difference between the boundary line position at 12 o'clock and the position at noon is L ON_theta_h_TH ; When δ S ≥ 0 and θ h_TH <δ S : When δ S ≥0 and θ h_TH ≥δ S hour: When δ S < 0 and θ h_TH < -δ S : When δ S < 0 and θ h_TH ≥ -δ S : Determine whether the latitude L to be analyzed has visible light imaging conditions at_sat The solar altitude angle is the solar altitude angle threshold value θ h_TH The local time L on the west side of the border line corresponding to the time T_TH_forenoon , local time on the east side T_TH_afternoon ; 8. The method for probabilistic analysis of sun-synchronous orbit satellite imaging based on illumination constraints according to claim 1, characterized in that: The step of determining whether the visible light imaging condition is met comprises: In L T_TH_forenoon ≤L T_edge ≤L T_TH_afternoon When the visible light imaging conditions are available; Among them, L T_TH_forenoon and L T_TH_afternoon are the local time on the west side and the local time on the east side of the boundary line corresponding to the position when the solar altitude angle is the solar altitude angle threshold value; L T_edge When the satellite is in the descending orbit segment and the latitude to be analyzed for visible light imaging conditions is pointing to the edge projection point.

9. A probability analysis device for sun-synchronous orbit satellite imaging based on illumination constraints, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the probability analysis method for sun-synchronous orbit satellite imaging based on illumination constraints as described in one of claims 1 to 8.

10. A computer program product, characterized in that The computer program product comprises: a computer program, which, when being executed, executes the illumination-constrained sun-synchronous orbit satellite imaging probability analysis method according to any one of claims 1 to 8.

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