An aircraft seamless scanning stable imaging method

Abstract

The present application belongs to the field of optical remote sensing, and particularly relates to a seamless scanning stable imaging method of an aircraft. The optical axis geographical tracking point precision is calculated by introducing the minimum uncertainty of system error to realize stable target tracking and clear imaging, a ground scanning range design model is established, the pointing error and target size are overcome to avoid target sieve, and the scanning design is carried out according to the ground parameters, and the ground scanning area is ploughed after multiple flights. The method can overcome the problem of missing scanning targets in the single flight process, is suitable for ploughing the ground scanning area after multiple flights, maintains the stability of the relative position relationship between the aircraft and the target, has the advantage of clear imaging, is suitable for intelligent recognition algorithm, and is also suitable for the case that the integrator time of the detector is long, such as low-cost infrared imaging or visible light imaging during dawn and dusk.

Description

Technical Field

[0001] This invention belongs to the field of optical remote sensing, specifically a seamless scanning and stable imaging method for aircraft. Background Technology

[0002] Depending on the different observation requirements of airborne optoelectronic equipment, observation types are mainly divided into staring observation and scanning search observation. The former is fixed-point observation of targets or areas with known coordinates, while the latter is wide-area observation of unknown areas. Compared with staring observation, scanning search has advantages such as a wider observation area and faster observation speed, making it a more effective observation method for gaining control of information in advance. Currently, most aircraft use periodic reciprocating motion to control the directional scanning of the optical imaging system servo platform. This scanning method is simple and easy to control; however, during aircraft movement, simple oscillation scanning cannot meet the observation requirements of stable geographic tracking, full area coverage, and clear imaging. Therefore, designing a seamless scanning stable imaging method suitable for aircraft has great practical application value. Summary of the Invention

[0003] Purpose of the invention This invention provides a seamless scanning and stable imaging method for aircraft, which solves the problems of non-full coverage of the observation area and blurred scanning images in existing aircraft scanning technologies.

[0004] Technical solution A seamless scanning and stable imaging method for aircraft is proposed. By introducing the minimum uncertainty of systematic error, the accuracy of the optical axis geographic tracking point is calculated to achieve stable target tracking and clear imaging. A ground scanning range design model is established to overcome pointing errors and target size to avoid target omissions. At the same time, the scanning design is carried out according to ground parameters, and the ground scanning area is covered in a plow-like manner after multiple flights.

[0005] Furthermore, this includes the following steps: Step 1: Obtain the aircraft's real-time flight parameters: flight altitude relative to the ground, flight speed, flight position, and the angle of the imaging system's servo frame.

[0006] Step two: After modeling the system, consider the aircraft's position error, attitude error, and optical servo pointing error, and then use theoretical calculations to obtain the accuracy of the imaging system's optical axis geographic tracking point.

[0007] Step 3: Determine the shift time based on the motion speed of the imaging system's servo frame and the aircraft's stable imaging operation time.

[0008] Step 4: Obtain the width of the scanning overlap area based on the minimum feature size of typical targets that may exist in the predetermined target area and the accuracy of the optical axis geographic tracking points.

[0009] in To scan the width of the overlapping region, denoted as the accuracy of the optical axis geographic tracking point, and s as the minimum feature size of a typical target.

[0010] Step 5: Establish the servo heading frame scanning model 1) Ground imaging width model; At a certain flight altitude, the aircraft imaging system performs a top-down imaging of the ground, and its field of view coverage area is approximately inverted trapezoidal, that is, the upper boundary imaging width is greater than the lower boundary imaging width. The altitude of the aircraft relative to the ground. The angle between the optical axis of the imaging system and the ground. For the imaging system's heading field of view, The pitch field of view of the imaging system. Let be the intersection of the optical axis of the aircraft imaging system and the ground, and the slant distance between the ground and the aircraft. From this, the widths of the upper, middle, and lower boundaries of the trapezoidal region of the ground imaging can be obtained. The vertical distance between the upper, middle and lower boundaries of the imaging area and the ground projection of the aircraft on the ground ): 4) Ground imaging scanning angle model When the aircraft imaging system scans, the servo frame moves, defining... For the heading frame scan angle, for The ground projection angle is the ground imaging scanning angle, and L is the center chord length between the intersection of the optical axis and the ground before and after scanning.

[0011] 5) Calculation model for adjacent gear scanning parameters 4) Geographic point distance model along / perpendicular to the flight path Distance of geographic scan point along flight path:

[0012] in t The shift time is the time interval between one swing of the servo frame.

[0013] Vertical distance of geographic scan point:

[0014] 6) Calculation model for scanning field of view imaging width During level flight scanning, sideslip angle The sideslip angle represents the angle between the center of the scanning frame and the velocity direction. When the velocity vector is to the right of the aircraft's plane of symmetry, the sideslip angle is positive, and vice versa.

[0015] When the field of view of the imaging system, the width of the ground overlap area, the relative flight altitude, and the scanning gear parameters are determined, the width of the ground imaging of the heading frame and the position of the geographic scanning point relative to the flight path are calculated at different pitch angles using models 1)-5).

[0016] Step 6: Based on the requirements of the aircraft observation coverage mission, input values ​​ODSX and ODSZ are set, and the corresponding heading and pitch scanning angles are obtained by back-calculation using the calculation models described in 1)-4).

[0017] Furthermore, step seven involves observing the geographic tracking point area and activating intelligent aircraft recognition when the frame moves to the designated position.

[0018] Furthermore, in step two, the specific method for determining the tracking point accuracy is as follows: Given the aircraft's current northeastern sky position Eb, Nb, H, flight altitude, heading, and attitude angle... Pitch angle Roll attitude angle Given the servo heading frame angle EH and pitch frame angle EB of the imaging system, the deviations (Δx, Δy) between the optical axis pointing towards the target position and the aircraft position are respectively: Δx = -H*(cos(EB)cos(EH)cos( sin( )+sin(EB)(cos( sin( )- cos( sin( sin( )+cos(EB)sin(EH)(cos( cos( )+sin( sin( sin( ))) / (cos( cos( -cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Δy=-H*(cos(EB)cos(EH)cos( cos( )+cos(EB)sin(EH)(cos( sin( sin( )- cos( sin( ))+sin(EB)(-cos( cos( sin( )-sin( sin( ))) / (cos( cos( sin(EB)-cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Ignoring altitude error, the platform's geographic location accuracy (uNd, uEd) is: uNd=

[0019] uEd= Then the accuracy of the optical axis geographic tracking point for:

[0020] Where u represents the minimum uncertainty.

[0021] Furthermore, in step 5, 1), the widths of the upper, middle, and lower boundaries of the imaging region are:

[0022]

[0023]

[0024] Vertical distance from the upper, middle, and lower boundaries of the imaging area to the ground projection of the aircraft:

[0025]

[0026]

[0027] Depth of field of view :

[0028] Furthermore, in step 5, 2), the ground imaging scanning angle is calculated. :

[0029]

[0030] Obtain the scanning angle of the heading frame :

[0031] Furthermore, in step 5, 3), based on the overlapping area of ​​the ground... This allows us to obtain the adjacent gear scanning angles of the heading frame angle:

[0032] Scanning angles of adjacent positions in the ground imaging area:

[0033] n Total field of view after file scan:

[0034] In the formula For the imaging system's heading field of view, n For scanning position, n 1,2,3,... Ground distance of movement of the field of view center of adjacent gear :

[0035] In the formula This is the offset angle between the scan center and the flight velocity vector.

[0036] Furthermore, in step 5, 3), in order to meet the full coverage observation requirements of areas of different sizes, the swath width of the observation area is divided into multiple blocks according to the ground projection of the aircraft's field of view, and the corresponding platform servo scanning motion is divided into multiple levels.

[0037] Furthermore, step 5) specifically refers to: The scanning field of view of the aircraft is the ground imaging area. When the servo mechanism swings, the scanning field of view will have three different relative positional relationships with the aircraft's velocity vector. Its imaging width is determined by the length of the four corner points of the imaging area and the perpendicular line to the velocity direction. The red dots represent the four corner points of the ground imaging area. For the two left corner points and the two right corner points that are closest to the ground projection in the velocity direction, if they are on opposite sides of the ground projection in the velocity direction, the imaging width of the scanning field of view is the sum of the distances on both sides. If they are on the same side, the imaging width of the scanning field of view is the difference between the distances on both sides.

[0038] The perpendicular distance D from each corner point to the velocity direction, The distance from the ground projection point of the aircraft to the corner point. The ground imaging scanning angle in model ② It can be expressed as follows:

[0039] Ground imaging scanning angle Substituting, we get:

[0040] In the formula, This is the angle between the heading frame angle boundaries in the relative velocity direction. In level flight, this is the angle relationship between the flight velocity vector, the scan frame center vector, and the scan center (the center vector of the scanned area). Therefore, the frame angle at the left corner point is... The frame angle of the right corner point is .

[0041] The distance from the lower left end of the scanning field of view to the velocity direction:

[0042] The distance from the lower right endpoint of the scanning field of view to the velocity direction:

[0043] The distance from the upper left end of the scanning field of view to the velocity direction:

[0044] The distance from the upper right endpoint of the scanning field of view to the velocity direction:

[0045] The corner point distribution is divided into three cases: four corner points distributed on both sides of the velocity direction, four corner points distributed on the left side of the velocity direction, and four corner points distributed on the right side of the velocity direction. The scanning field of view imaging widths for the three cases are as follows: Both sides

[0046] Left side

[0047] right side

[0048] Technical effect This invention provides a seamless scanning and stable imaging method for aircraft. This method considers the target size and the accuracy of the optical axis geographic tracking point when calculating the overlapping area of ​​the scan, which can overcome the problem of missing targets during a single flight path and is suitable for plowing up the ground scanning area after multiple flights. At the same time, this method maintains the stability of the relative positional relationship between the aircraft and the target, and has the advantage of clear imaging, which is suitable for intelligent recognition algorithms. In addition, this stable imaging method is also suitable for situations where the detector integration time is long, such as low-cost infrared imaging or visible light imaging during dawn and dusk. Attached Figure Description

[0049] Figure 1 For ground imaging width model; Figure 2 This is a model for the range of ground imaging scanning angles. Figure 3 Schematic diagram of ground projection for different scanning fields of view; Figure 4 Calculation model for the overlapping area of ​​adjacent gears; Figure 5 The imaging width model for the scanning field of view; Figure 6 This is a diagram showing the location of the corner points; Figure 7a This is a schematic diagram of the left corner frame angle; Figure 7b This is a schematic diagram of the frame corner at the right corner point; Figure 8 Workflow diagram for a seamless scanning stabilized imaging method for aircraft. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to reference are exemplary and intended to explain this invention, and should not be construed as limiting the 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. The embodiments of this invention will be described in detail below.

[0051] Figure 8 This is a schematic diagram of the workflow of the seamless scanning stabilized imaging method for aircraft provided by the present invention, as shown below. Figure 8 As shown, the specific implementation steps of the seamless scanning stabilized imaging method for aircraft provided by the present invention include the following: S1: Determine the ground parameters of the observation area of ​​the aircraft, including the width of the observation area, the minimum feature size of the target in the area, the altitude, and the scan shift time.

[0052] S2: Construct a scanning observation device, and install the servo frame and speed, altitude, and attitude angle acquisition modules on the aircraft. Install the optical imaging system on the servo frame. When the optical axis of the optical system is horizontal, the sum of the pitch angle of the aircraft and the pitch angle of the servo frame is 0 degrees.

[0053] S3: After the aircraft is installed, calibrate the installation error of the calibration system and the measurement error of each module.

[0054] S4: Based on the above errors, determine the accuracy of the geographic tracking point of the imaging system's optical axis.

[0055] S5: Determine the size of the overlapping area between adjacent gears in the scanning area based on the accuracy of the imaging system's optical axis geographic tracking point and the minimum feature size of the target in the observation area.

[0056] S6: After determining the size of the overlapping area between adjacent gears, establish a servo heading frame scanning calculation model, including single field of view ground imaging width calculation, field of view coverage depth calculation, ground imaging scanning angle range calculation, geographic scanning point distance along / perpendicular flight path calculation, and scanning field of view imaging width calculation.

[0057] S7: Calculate the scanning field of view imaging width at different pitch angles using the model described in S6, and determine the distance ODSX / ODSZ of the geographic scan point along / vertically to the flight path based on the flight mission observation swath width in S1.

[0058] S8: During flight, the aircraft acquires real-time data on altitude, speed, and attitude angles through various sensor modules.

[0059] S9: Using the data in S8 and the model output described in S7, substitute them back into the heading frame scanning calculation model in S6 to obtain the motion law of the servo frame during flight. The servo motor drives the imaging system to perform periodic heading motion.

[0060] S10: When the center of the imaging system's servo heading frame points to the geographic tracking point, angle and speed compensation are calculated based on the aircraft's real-time flight speed and attitude angle data to maintain a fixed line-of-sight angular velocity for a period of time. During this period, the optical system's imaging is clear and stable, resulting in good observation effects.

[0061] Example A seamless scanning stabilized imaging method for aircraft calculates the accuracy of the optical axis geographic tracking point by introducing the minimum uncertainty of systematic errors to achieve stable target tracking and clear imaging. It establishes a ground scanning range design model to overcome pointing errors and target size limitations, avoiding target gaps. Furthermore, it allows for scanning design based on ground parameters, facilitating thorough coverage of the ground scanning area after multiple flights. The method includes the following steps: 1) Obtain real-time flight parameters of the aircraft: flight altitude relative to the ground, flight speed, flight position, and servo frame angle of the imaging system, etc.

[0062] 2) After modeling the system, considering the aircraft's position error, attitude error, and optical servo pointing error, the accuracy of the imaging system's optical axis geographic tracking point is obtained through theoretical calculations. The specific method for determining the tracking point accuracy is as follows: Given the aircraft's current northeast-sky position (Eb, Nb, H (flight altitude)) and heading / attitude angles... Pitch angle Roll attitude angle Given the servo heading frame angle EH and pitch frame angle EB of the imaging system, the deviations (Δx, Δy) between the optical axis pointing towards the target position and the aircraft position are respectively: Δx = -H*(cos(EB)cos(EH)cos( sin( )+sin(EB)(cos( sin( )- cos( sin( sin( )+cos(EB)sin(EH)(cos( cos( )+sin( sin( sin( ))) / (cos( cos( -cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Δy=-H*(cos(EB)cos(EH)cos( cos( )+cos(EB)sin(EH)(cos( sin( sin( )- cos( sin( ))+sin(EB)(-cos( cos( sin( )-sin( sin( ))) / (cos( cos( sin(EB)-cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Ignoring altitude error, the platform's geographic location accuracy (uNd, uEd) is: uNd=

[0063] uEd= Then the accuracy of the optical axis geographic tracking point for:

[0064] Where u represents the minimum uncertainty: 3) Determine the shift time based on the motion speed of the imaging system's servo frame and the aircraft's stable imaging working time.

[0065] 4) The width of the scanning overlap area is obtained based on the minimum feature size of typical targets that may exist in the predetermined target area and the accuracy of the optical axis geographic tracking point:

[0066] in To scan the width of the overlapping region, denoted as the accuracy of the optical axis geographic tracking point, and s as the minimum feature size of a typical target.

[0067] 5) Establish a servo heading frame scanning model At a certain flight altitude, the ground imaging width model shows that when an aircraft's imaging system performs a top-down image of the ground, its field of view is approximately inverted trapezoidal, meaning the upper boundary imaging width is greater than the lower boundary imaging width. For example... Figure 1 As shown in the figure The altitude of the aircraft relative to the ground. The angle between the optical axis of the imaging system and the ground. For the imaging system's heading field of view, The pitch field of view of the imaging system. Let be the intersection of the optical axis of the aircraft imaging system and the ground, and the slant distance between the intersection and the aircraft. From this, the widths of the upper, middle, and lower boundaries of the trapezoidal region of the ground imaging can be obtained. ) and the vertical distance from the upper, middle and lower boundaries of the imaging area projected onto the ground of the aircraft ( : Width of the upper, middle and lower boundaries of the imaging region:

[0068]

[0069]

[0070] Vertical distance from the upper, middle, and lower boundaries of the imaging area to the ground projection of the aircraft:

[0071]

[0072]

[0073] Depth of field of view :

[0074] When the ground imaging scanning angle model aircraft imaging system scans, the servo frame will move, defining... For the heading frame scan angle, for The ground projection angle is the ground imaging scanning angle, and L is the center chord length between the intersection of the optical axis and the ground before and after scanning.

[0075] Calculate the ground imaging scanning angle :

[0076]

[0077] Obtain the scanning angle of the heading frame :

[0078] To meet the full coverage observation requirements of areas of different sizes, the adjacent gear scanning parameter calculation model divides the observation area into multiple blocks based on the ground projection of the aircraft's field of view. The corresponding platform servo scanning motion is divided into multiple gears. The blue box area in the figure above represents the ground projection of the scanning field of view for three different gears.

[0079] According to the above Figure 4 Overlapping area of ​​the middle ground This allows us to obtain the adjacent gear scanning angles of the heading frame angle:

[0080] Scanning angles of adjacent positions in the ground imaging area:

[0081] n Total field of view after file scan:

[0082] In the formula For the imaging system's heading field of view, n For scanning position, n 1,2,3,... Ground distance of movement of the field of view center of adjacent gear :

[0083] In the formula This is the offset angle between the scan center and the flight velocity vector.

[0084] Geographic point distance along / perpendicular flight path model geographic scan point distance along flight path:

[0085] in t The shift time is the time interval between one swing of the servo frame.

[0086] Vertical distance of geographic scan point:

[0087] The scanning field of view imaging width calculation model shows the sideslip angle during level flight scanning of the aircraft. The sideslip angle represents the angle between the center of the scanning frame (0 degrees for the heading frame) and the velocity direction. When the velocity vector is to the right of the aircraft's plane of symmetry, the sideslip angle is positive, and vice versa.

[0088] The aircraft's scanning field of view is the ground imaging area. When the servo mechanism swings, the scanning field of view will have three different relative positional relationships with the aircraft's velocity vector. Its imaging width is determined by the length of the perpendicular lines from the four corner points of the imaging area to the velocity direction, such as... Figure 5 As shown in the figure. The red dots represent the four corner points of the ground imaging area. For the two left corner points and the two right corner points that are closest to the ground projection in the velocity direction, if they are on opposite sides of the ground projection in the velocity direction, the scanning field of view imaging width is the sum of the distances on both sides. If they are on the same side, the scanning field of view imaging width is the difference between the distances on both sides.

[0089] The perpendicular distance D from each corner point to the velocity direction is as follows: Figure 6 As shown, The distance from the ground projection point of the aircraft to the corner point. The ground imaging scanning angle in model ② It can be expressed as follows:

[0090] Ground imaging scanning angle Substituting, we get:

[0091] In the formula, It is the angle between the heading frame angle boundaries in the relative velocity direction. Figure 7a and Figure 7b This represents the angular relationship between the flight velocity vector, the scan frame center vector, and the scan center (center vector of the scanned area) when the platform is in level flight attitude. Therefore, the frame angle of the left corner point is... The frame angle of the right corner point is .

[0092] The distance from the lower left end of the scanning field of view to the velocity direction:

[0093] The distance from the lower right endpoint of the scanning field of view to the velocity direction:

[0094] The distance from the upper left end of the scanning field of view to the velocity direction:

[0095] The distance from the upper right endpoint of the scanning field of view to the velocity direction:

[0096] The corner point distribution is divided into three cases: four corner points distributed on both sides of the velocity direction, four corner points distributed on the left side of the velocity direction, and four corner points distributed on the right side of the velocity direction. The scanning field of view imaging widths for the three cases are as follows: Both sides

[0097] Left side

[0098] right side

[0099] When parameters such as the field of view of the imaging system, the width of the ground overlap area, the relative flight altitude, and the scanning mode are determined, models ① to ⑤ can be used to calculate the width of the ground imaging scan by the heading frame and the position of the geographic scanning point (the point pointed to by the center of the frame) relative to the flight path at different pitch angles.

[0100] 6) Based on the requirements of the aircraft's observation coverage mission, input values ​​ODSX and ODSZ are set, and the corresponding heading and pitch scanning angles can be obtained by back-calculation using the calculation models described in ①~④.

[0101] 7) When the frame moves to the designated position, observe the geographic tracking point area and activate the aircraft's intelligent recognition.

[0102] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0103] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0104] The above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the above-disclosed technical content to make changes or modifications to equivalent embodiments and apply them to other fields. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, as well as any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A seamless scanning stabilized imaging method for aircraft, characterized in that, The accuracy of the optical axis geographic tracking point is calculated by introducing the minimum uncertainty of systematic error to achieve stable target tracking and clear imaging. A ground scanning range design model is established to overcome pointing errors and target size to avoid target omissions. At the same time, scanning is designed based on ground parameters, and the ground scanning area is covered in a plow-like manner after multiple flights. The process includes the following steps: Step 1: Obtain real-time flight parameters of the aircraft: flight altitude relative to the ground, flight speed, flight position, and servo frame angle of the imaging system; Step 2: After modeling the system, consider the aircraft's position error, attitude error, and optical servo pointing error, and then use theoretical calculations to obtain the accuracy of the imaging system's optical axis geographic tracking point. Step 3: Determine the shift time based on the motion speed of the imaging system's servo frame and the aircraft's stable imaging operation time; Step 4: Obtain the width of the scanning overlap area based on the minimum feature size of typical targets that may exist in the predetermined target area and the accuracy of the optical axis geographic tracking points. ,in To scan the width of the overlapping region, is the accuracy of the optical axis geographic tracking point, and s is the minimum feature size of a typical target; Step 5: Establish the servo heading frame scanning model 1) Ground imaging width model; At a certain flight altitude, the aircraft imaging system performs downward imaging of the ground, and its field of view coverage area is approximately inverted trapezoidal, that is, the upper boundary imaging width is greater than the lower boundary imaging width. The altitude of the aircraft relative to the ground. The angle between the optical axis of the imaging system and the ground. For the imaging system's heading field of view, The pitch field of view of the imaging system. Let the intersection of the optical axis of the aircraft imaging system and the ground, and the slant distance between the ground and the aircraft, be the points where the system's optical axis intersects with the ground; from this, the widths of the upper, middle, and lower boundaries of the trapezoidal region of the ground imaging can be obtained. The vertical distance between the upper, middle and lower boundaries of the imaging area and the ground projection of the aircraft on the ground : 2) Ground imaging scanning angle model When the aircraft imaging system scans, the servo frame moves, defining... For the heading frame scan angle, for The ground projection angle is the ground imaging scanning angle, and L is the center chord length between the intersection of the optical axis and the ground before and after scanning; 3) Calculation model for adjacent gear scanning parameters 4) Geographic point distance model along / perpendicular to the flight path Distance of geographic scan points along the flight path: , where t is the shift time, which is the time interval between one swing of the servo frame; Vertical distance of geographic scan point: 5) Calculation model for scanning field of view imaging width During level flight scanning, sideslip angle The sideslip angle represents the angle between the center of the scanning frame and the velocity direction. When the velocity vector is to the right of the aircraft's plane of symmetry, the sideslip angle is positive, and vice versa. When the field of view of the imaging system, the width of the ground overlap area, the relative flight altitude and the scanning gear parameters are determined, the width of the ground imaging scanned by the heading frame and the position of the geographic scanning point relative to the flight path are calculated at different pitch angles using models 1)-5). Step 6: Based on the requirements of the aircraft observation coverage mission, input values ​​ODSX and ODSZ are set, and the corresponding heading and pitch scanning angles are obtained by back-calculation using the calculation models described in 1)-4).

2. The method as described in claim 1, characterized in that, It also includes step seven, which involves observing the geographic tracking point area and enabling intelligent recognition of the aircraft when the frame moves to the designated position.

3. The method as described in claim 1, characterized in that, Step two, specifically, involves determining the tracking point accuracy as follows: Given the aircraft's current northeastern sky position Eb, Nb, H, flight altitude, heading, and attitude angle... Pitch angle Roll attitude angle Given the servo heading frame angle EH and pitch frame angle EB of the imaging system, the deviations (Δx, Δy) between the optical axis pointing towards the target position and the aircraft position are respectively: Δx=-H*(cos(EB)cos(EH)cos( )without( )+sin(EB)(cos( )without( )- cos( )without( )without( )+cos(EB)sin(EH)(cos( )cos( )+sin( )without( )without( ))) / (cos( )cos( -cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Δy=-H*(cos(EB)cos(EH)cos( )cos( )+cos(EB)sin(EH)(cos( )without( )without( )- cos( )without( ))+sin(EB)(-cos( )cos( )without( )-without( )without( ))) / (cos( )cos( )sin(EB)-cos(EB)cos( )sin(EH)sin( )+cos(EB)cos(EH)sin( )) Ignoring altitude error, the platform's geographic location accuracy (uNd, uEd) is: uNd= , uEd= Then the accuracy of the optical axis geographic tracking point for: , where u represents the minimum uncertainty.

4. The method as described in claim 1, characterized in that, In step 5, 1), the widths of the upper, middle, and lower boundaries of the imaging region are: ， ， ， Vertical distance from the upper, middle, and lower boundaries of the imaging area to the aircraft's ground projection: ， ， ， Depth of field of view : 。 5. The method as described in claim 1, characterized in that, In step 5, 2), the ground imaging scanning angle is calculated. : ， ， Obtain the scanning angle of the heading frame : 。 6. The method as described in claim 1, characterized in that, In step 5, 3), based on the overlapping area of ​​the ground... The adjacent gear scanning angles of the heading frame angle are obtained: ， Scanning angles of adjacent positions in the ground imaging area: ， Total field of view for heading after n-level scan: ， In the formula The imaging system's heading field of view is denoted by n, where n is the scan level. 1,2,3,... Ground distance of movement of the field of view center of adjacent gears : ， In the formula This is the offset angle between the scan center and the flight velocity vector.

7. The method as described in claim 1, characterized in that, In step 5, 3), in order to meet the full coverage observation requirements of areas of different sizes, the observation area is divided into multiple sections according to the ground projection of the aircraft's field of view, and the corresponding platform servo scanning motion is divided into multiple levels.

8. The method as described in claim 1, characterized in that, Step 5, 5) specifically refers to: The scanning field of view of the aircraft is the ground imaging area. When the servo mechanism swings, the scanning field of view will have three different relative positional relationships with the aircraft's velocity vector. Its imaging width is determined by the length of the four corner points of the imaging area and the perpendicular line of the velocity direction. The red dots are the four corner points of the ground imaging area. For the two left corner points and the two right corner points that are closest to the ground projection in the velocity direction, if they are on both sides of the ground projection in the velocity direction, the imaging width of the scanning field of view is the sum of the distances on both sides. If they are on the same side, the imaging width of the scanning field of view is the difference between the distances on both sides. The perpendicular distance D from each corner point to the velocity direction, The distance from the ground projection point of the aircraft to the corner point. The ground imaging scanning angle in model ② It can be expressed by the following formula: ， Ground imaging scanning angle Substituting, we get: ， In the formula, The angle between the relative velocity direction and the heading frame angle boundary; the angle relationship between the flight velocity vector, the scanning frame center vector, and the scanning center (the center vector of the scanned area) under level flight attitude; therefore, the frame angle at the left corner point is... The frame angle of the right corner point is ; The distance from the lower left end of the scanning field of view to the velocity direction: ， The distance from the lower right endpoint of the scanning field of view to the velocity direction: ， The distance from the upper left end of the scanning field of view to the velocity direction: ， The distance from the upper right endpoint of the scanning field of view to the velocity direction: ， The corner point distribution is divided into three cases: four corner points distributed on both sides of the velocity direction, four corner points distributed on the left side of the velocity direction, and four corner points distributed on the right side of the velocity direction; the scanning field of view imaging widths for the three cases are as follows: Both sides: ， Left side: ， Right side: 。

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