Method for determining parameters of airborne photoelectric system for target area reconnaissance and simulation system thereof

Abstract

The application provides an airborne photoelectric system parameter determination method for target area reconnaissance and a simulation system thereof, adopts a simulation method to determine the airborne photoelectric system parameters, and the simulation method comprises the following steps: S10, creating a coordinate system based on the positional relationship between the airborne photoelectric system and the target area; S20, setting parameters for the aircraft and the airborne photoelectric system; S30, calculating the inner diameter of the scanning ring and the round-trip distance of the aircraft based on the set parameters; S40, calculating the focal length of the thermal imager according to the clear imaging requirement; S50, calculating the maximum outer diameter of the scanning ring based on the focal length of the thermal imager according to the imaging pixel number requirement; S60, establishing a functional relationship formula of the length and width of the rectangular scanning area, and calculating the area of the rectangular target area and the area of the scanning area; and S70, performing iterative optimization on the parameters. The application has low cost and can be repeatedly used, and the optimal photoelectric parameters can be obtained under different flight conditions in the laboratory simulation, thereby bringing significant economic benefits to the unmanned aerial vehicle system application.

Description

Technical Field

[0001] This invention relates to the field of UAV optoelectronic reconnaissance technology, and in particular to a method for determining the parameters of an airborne optoelectronic system for target area reconnaissance and its simulation system. Background Technology

[0002] A single optoelectronic system has a limited reconnaissance area, but multiple optoelectronic systems, when equipped with multiple UAVs, can simultaneously perform detection, identification, and tracking tasks on fixed and moving targets within a certain area.

[0003] Currently, the common method for multi-aircraft collaborative reconnaissance is to achieve field-of-view coverage of a certain area by designing UAV flight paths and performing path planning. This method often involves complex algorithms and is difficult to implement in engineering. In order to complete regional reconnaissance missions more efficiently and cost-effectively using existing UAVs and electro-optical payloads, a certain area can be directly divided into several rectangular grids. An electro-optical system is installed in each grid and mounted on a UAV. The UAV only performs one-dimensional back-and-forth movement on one side of the grid, while the electro-optical system performs a two-dimensional grid area coverage by scanning at a certain pitch angle and azimuth velocity, thus completing the detection of targets within the area.

[0004] The purpose of target detection is often to facilitate the next step of target processing. Therefore, in practical applications, there are certain requirements for the reconnaissance time of the grid area, which depends on the processing time of the superior. It is required to complete the search of the entire grid within the specified time without any blind spots or missed scans.

[0005] Increasing the area covered by the ring band within a certain timeframe can increase the surveillance area; conversely, increasing the area covered by the ring band within a given surveillance area can shorten reconnaissance time. Therefore, increasing the area covered by the ring band is essential. The most straightforward method is to decrease the inner diameter of the ring band and increase its outer diameter. There are two methods:

[0006] One approach is to increase the coverage area of ​​a single field of view (SLP). The size of the ground area covered by a SLP is related to the aircraft's altitude, pitch angle, and field of view angle. The higher the aircraft altitude, the larger the SLP coverage area; the smaller the pitch angle, the larger the SLP coverage area; and the larger the field of view angle, the larger the SLP coverage area. However, as the pitch angle decreases, once it exceeds the detector's detection capability, the target detection and identification task cannot be completed. The field of view angle is limited by the detector's array size and focal length and cannot be increased indefinitely. Furthermore, the aircraft altitude is affected by cloud height and cannot be increased arbitrarily. This method has obvious limitations.

[0007] Another approach is step scanning. Since single-field-of-view capabilities are limited, we consider reducing the inner diameter of the ring and increasing its outer diameter by changing the pitch angle through the movement of the photoelectric payload. Changing the pitch angle increases the flexibility of the scanning method, but the system complexity and feasibility must also be considered. Furthermore, the pitch angle cannot be arbitrarily chosen; aircraft speed can cause image shift, resulting in image blurring. Therefore, the minimum inner diameter must be able to overcome the image shift effect and meet the requirements for clear imaging; the maximum outer diameter must meet the pixel count requirements for target detection and recognition.

[0008] Meanwhile, due to the application of infrared / visible light area array staring devices, a retrace compensation mechanism is needed to compensate for the image shift caused by the turret pod's peripheral scanning. The image shift caused by the UAV's flight is compensated by the photoelectric system itself. This means that the photoelectric payload must meet the requirements for target detection and identification, but it must not produce a blurred image due to the UAV's movement. To obtain such a set of photoelectric payload parameters that meet the requirements, a large number of real flight tests are currently needed, requiring a significant investment of human, material, and financial resources. Summary of the Invention

[0009] The technical problem to be solved by this invention is how to obtain photoelectric payload parameters that meet the detection requirements at low cost. This invention proposes a method for determining the parameters of an airborne photoelectric system for target area reconnaissance and its simulation system.

[0010] According to an embodiment of the present invention, a method for determining the parameters of an airborne optoelectronic system for target area reconnaissance employs a simulation method to determine the parameters of the airborne optoelectronic system, the simulation method comprising:

[0011] S10, Create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area;

[0012] S20, setting parameters for the aircraft and the airborne optoelectronic system;

[0013] S30, in the coordinate system, based on the set parameters, calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft;

[0014] S40, calculate the focal length of the thermal imager based on the requirements for clear imaging;

[0015] S50, based on the required number of imaging pixels and the focal length of the thermal imager, calculate the maximum outer diameter of the scanning ring;

[0016] S60, establish the functional relationship between the length and width of the rectangular scanning area, and calculate the area of ​​the rectangular target area and the area of ​​the scanning area;

[0017] S70 performs iterative optimization of parameters.

[0018] According to some embodiments of the present invention, the method further includes:

[0019] S80, based on the reconnaissance mission and the area of ​​the obtained rectangular target region, determine the total number of aircraft.

[0020] In some embodiments of the present invention, step S70 includes:

[0021] S71, establish the functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation;

[0022] S72, calculate the instantaneous field of view angle and the vertical resolution of the optical axis, the horizontal resolution of the optical axis, the minimum resolution vertical, the minimum resolution horizontal, the maximum resolution vertical, and the maximum resolution horizontal at the said pitch angle, so as to measure the target imaging size.

[0023] According to some embodiments of the present invention, step S10 specifically includes:

[0024] Treating the airborne optoelectronic system and the aircraft as a single point, establish coordinate system one and coordinate system two. Coordinate system one takes the projection position of the aircraft on the ground as the origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate system two takes the vertex of the rectangular target area as the origin, the longer side as the x-axis, and the shorter side as the y-axis.

[0025] In some embodiments of the present invention, step S20, setting parameters includes: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scanning area width.

[0026] A target area reconnaissance airborne optoelectronic system parameter simulation system according to an embodiment of the present invention includes:

[0027] The coordinate system creation module is used to create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area.

[0028] The parameter setting module is used to set parameters for the aircraft and the airborne optoelectronic system;

[0029] The calculation module is used to calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft based on the set parameters in the coordinate system.

[0030] Calculate the focal length of the thermal imager based on the requirements for clear imaging;

[0031] Based on the required number of imaging pixels and the focal length of the thermal imager, the maximum outer diameter of the scanning ring is calculated.

[0032] Establish a functional relationship between the length and width of the rectangular scanning region, and calculate the area of ​​the rectangular target region and the area of ​​the scanning region;

[0033] The iterative optimization module is used to perform iterative optimization of parameters.

[0034] According to some embodiments of the present invention, the iterative optimization module is specifically used for:

[0035] Establish a functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation;

[0036] The instantaneous field of view angle and the vertical resolution, horizontal resolution, minimum resolution vertical, minimum resolution horizontal, maximum resolution vertical, and maximum resolution horizontal at the pitch angle are calculated to measure the target imaging size.

[0037] In some embodiments of the present invention, the coordinate system creation module is specifically used for:

[0038] Treating the airborne optoelectronic system and the aircraft as a single point, establish coordinate system one and coordinate system two. Coordinate system one takes the projection position of the aircraft on the ground as the origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate system two takes the vertex of the rectangular target area as the origin, the longer side as the x-axis, and the shorter side as the y-axis.

[0039] According to some embodiments of the present invention, the parameter setting module performs parameter setting including: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scan area width.

[0040] In some embodiments of the present invention, the simulation system further includes:

[0041] The determination module is used to determine the total number of aircraft based on the area of ​​the rectangular target region obtained from the reconnaissance mission.

[0042] The present invention has the following beneficial effects:

[0043] This invention provides a simulation method for designing airborne optoelectronic system parameters for target area reconnaissance. This method utilizes existing low-cost optoelectronic pods to achieve area coverage through circumferential scanning at specific pitch and azimuth angles, eliminating the need for dedicated scanning-type optoelectronic payloads for area scanning. This will bring significant economic benefits to UAV system applications. When the UAV's flight speed is constant at a certain altitude, and the field of view, pitch angle, and other parameters of the optoelectronic payload are known, the area of ​​the grid region can be calculated by traversing it within a specified time. For area reconnaissance, knowing the grid area allows for the calculation of the total number of UAVs required, playing a crucial role in the top-level planning of UAV system applications. The proposed simulation model is based on rigorous mathematical derivation using the detector imaging principle and the spatial geometric relationship between the grid region optoelectronic reconnaissance system and the target. It is low-cost, reusable, and can obtain optimal optoelectronic parameters under different flight conditions simulated in the laboratory. Attached Figure Description

[0044] Figure 1 A flowchart illustrating a method for determining parameters of an airborne optoelectronic system for target area reconnaissance according to an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of a ring scanning airborne optoelectronic system according to an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the ground coverage area scanned by an airborne optoelectronic system according to an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of the coordinate system for calculating the pitch angle of the photoelectric load using circumferential scanning imaging according to an embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram of the ground projection coordinate system for circumferential scanning imaging according to an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of a circular scanning image when d = 2r according to an embodiment of the present invention;

[0050] Figure 7 This is a schematic diagram of the area of ​​the circumferential scanning imaging region and the inscribed rectangular region according to an embodiment of the present invention;

[0051] Figure 8 This is a schematic diagram of the simulation interface of the simulation system according to an embodiment of the present invention. Detailed Implementation

[0052] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

[0053] The steps described in the specification and the flowcharts in the accompanying drawings of this invention are not necessarily to be strictly followed according to the step numbers; the execution order of the steps can be changed. Furthermore, certain steps can be omitted, multiple steps can be combined into one step, and / or one step can be broken down into multiple steps.

[0054] This invention addresses the problem of clear imaging in target mesh-type area reconnaissance using electro-optical pods with step scanning. It proposes a simulation method for designing airborne electro-optical system parameters. In a laboratory environment, it generates target mesh-type area reconnaissance data of the electro-optical system by analyzing the interrelationships between various parameters such as reconnaissance time, ring coverage area, and electro-optical payload. This verifies the key technologies of low-cost electro-optical pod step scanning reconnaissance, supports the top-level planning of UAV system applications, and supports the effective implementation of multi-aircraft collaborative mesh-type area reconnaissance.

[0055] According to the method for determining the parameters of an airborne optoelectronic system for target area reconnaissance according to an embodiment of the present invention, the parameters of the airborne optoelectronic system are determined by simulation, such as... Figure 1 As shown, the simulation method includes:

[0056] S10, Create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area;

[0057] According to some embodiments of the present invention, step S10 specifically includes:

[0058] The airborne optoelectronic system and the aircraft are considered as a single point; the relative positions of the optoelectronic payload and the aircraft are negligible compared to the length of the reconnaissance grid area, so the optoelectronic payload and the aircraft are approximately considered as a single point in space.

[0059] Two coordinate systems are established: Coordinate System 1 and Coordinate System 2. Coordinate System 1 uses the projected position of the aircraft on the ground as its origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate System 2 uses the vertices of the rectangular target area as its origin, the longer side as the x-axis, and the shorter side as the y-axis. Coordinate System 1 is used to analyze the constraint relationship between the selection of the electro-optical payload's pitch angle and target identification and clear imaging, while Coordinate System 2 is used to calculate the coverage area of ​​the grid region.

[0060] S20 sets parameters for the aircraft and its onboard optoelectronic systems. These parameters consist of five sets: thermal imager parameters, aircraft parameters, turntable parameters, target parameters, and scanning area.

[0061] Thermal imager parameters include pixel size u, number of pixels a×b, integration time τ, focal length f, field of view β, and instantaneous field of view α; aircraft parameters include aircraft speed v, altitude H, aircraft turning radius r', aircraft round-trip distance d, and target revisit time T; turntable parameters include pitch angle γ1, pitch angle γ2, and pitch angle γ; target parameters include target size M, target image size n, and vertical resolution δ.c Horizontal resolution δs of the optical axis, vertical resolution δs of the minimum resolution cmin Minimum resolution level δ smin Maximum resolution vertical δ cmax Maximum resolution level δ smax The scanning area parameters include the inner diameter r of the scanning ring, the outer diameter R1 of the scanning ring, the outer diameter R2 of the scanning ring, the maximum outer diameter R of the scanning ring, the length L of the rectangular scanning area, the width W of the rectangular scanning area, the area S' of the rectangular area, and the area S of the scanning area.

[0062] In some embodiments of the present invention, step S20, setting parameters includes: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scanning area width.

[0063] S30, in the coordinate system, calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft based on the set parameters;

[0064] S40, calculate the focal length of the thermal imager based on the requirements for clear imaging;

[0065] S50 calculates the maximum outer diameter of the scanning ring based on the required number of imaging pixels and the focal length of the thermal imager. The maximum outer diameter of the scanning ring must ensure that no images are missed while also meeting the pixel requirements for detection and recognition.

[0066] S60, establish the functional relationship between the length and width of the rectangular scanning area, and calculate the area of ​​the rectangular target area and the area of ​​the scanning area;

[0067] S70 performs iterative optimization of parameters.

[0068] In some embodiments of the present invention, step S70 includes:

[0069] S71, establish the functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation;

[0070] Calculate the pitch angle γ1 based on the minimum inner diameter obtained in step S30, and calculate the outer diameter R1 of the scanning ring at pitch angle γ1, and the outer diameter R2 of the scanning ring at the theoretical pitch angle γ′2, and the pitch angle γ2 at R2. During the iterative calculation, based on the maximum outer diameter R of the scanning ring obtained in step S50, if R1>R, then take R1=R; otherwise, use the pitch angle γ1 to calculate R1. If R2>R, then take R2=R; otherwise, use the pitch angle γ′2 to calculate R2. At the same time, if R2==R, then γ2 is the pitch angle taken at R2; otherwise, γ2=γ′2. If the judgment condition is met, the simulation ends.

[0071] S72 calculates the instantaneous field of view angle and the vertical resolution, horizontal resolution, minimum resolution vertical, minimum resolution horizontal, maximum resolution vertical, and maximum resolution horizontal at the elevation angle, in order to measure the size of the target image.

[0072] According to some embodiments of the present invention, the method further includes:

[0073] S80, based on the area of ​​the rectangular target region obtained during the reconnaissance mission, determines the total number of aircraft.

[0074] The airborne optoelectronic system parameter simulation system for target area reconnaissance according to an embodiment of the present invention includes: a coordinate system creation module, a parameter setting module, a calculation module, and an iterative optimization module.

[0075] The coordinate system creation module is used to create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area.

[0076] In some embodiments of the present invention, the coordinate system creation module is specifically used for:

[0077] Treating the airborne optoelectronic system and the aircraft as a single point, establish coordinate system one and coordinate system two. Coordinate system one takes the projection position of the aircraft on the ground as the origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate system two takes the vertex of the rectangular target area as the origin, the longer side as the x-axis, and the shorter side as the y-axis.

[0078] The parameter setting module is used to set parameters for the aircraft and its onboard optoelectronic systems;

[0079] According to some embodiments of the present invention, the parameter setting module performs parameter setting including: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scan area width.

[0080] The calculation module is used to calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft in a coordinate system based on the set parameters.

[0081] Calculate the focal length of the thermal imager based on the requirements for clear imaging;

[0082] Based on the required number of imaging pixels and the focal length of the thermal imager, the maximum outer diameter of the scanning ring is calculated.

[0083] Establish a functional relationship between the length and width of the rectangular scanning region, and calculate the area of ​​the rectangular target region and the area of ​​the scanning region;

[0084] The iterative optimization module is used to perform iterative optimization of parameters.

[0085] According to some embodiments of the present invention, the iterative optimization module is specifically used for:

[0086] Establish a functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation;

[0087] The instantaneous field of view angle and the vertical resolution, horizontal resolution, minimum resolution vertical, minimum resolution horizontal, maximum resolution vertical, and maximum resolution horizontal at the elevation angle are calculated to measure the size of the target image.

[0088] In some embodiments of the present invention, the simulation system further includes:

[0089] The determination module is used to determine the total number of aircraft based on the area of ​​the obtained rectangular target region, according to the reconnaissance mission.

[0090] The present invention has the following beneficial effects:

[0091] This invention provides a simulation method for designing airborne optoelectronic system parameters for target area reconnaissance. This method utilizes existing low-cost optoelectronic pods to achieve area coverage through circumferential scanning at specific pitch and azimuth angles, eliminating the need for dedicated scanning-type optoelectronic payloads for area scanning. This will bring significant economic benefits to UAV system applications. When the UAV's flight speed is constant at a certain altitude, and the field of view, pitch angle, and other parameters of the optoelectronic payload are known, the area of ​​the grid region can be calculated by traversing it within a specified time. For area reconnaissance, knowing the grid area allows for the calculation of the total number of UAVs required, playing a crucial role in the top-level planning of UAV system applications. The proposed simulation model is based on rigorous mathematical derivation using the detector imaging principle and the spatial geometric relationship between the grid region optoelectronic reconnaissance system and the target. It is low-cost, reusable, and can obtain optimal optoelectronic parameters under different flight conditions simulated in the laboratory.

[0092] The present invention is described below with reference to specific embodiments. It should be noted that the following description is merely exemplary and should not be construed as a specific limitation of the present invention.

[0093] The optoelectronic pod is mounted on a drone and performs a circular scan at a certain pitch angle and rotation speed. As the drone flies back and forth along the centerline of a fixed monitoring area, it achieves field-of-view coverage of the monitored area within a certain time, meeting the target alarm requirements, such as... Figure 2 As shown. The single-field-of-view projection of a photoelectric payload onto the ground has a limited coverage area, such as... Figure 3 The red area represents the field of view that can be expanded after a periodic scan of the payload; the ground coverage area after one scan can be approximated as [missing information]. Figure 3 The yellow ring shown expands its coverage area as the aircraft moves.

[0094] Step 1: Establish two rectangular coordinate systems. Coordinate system one uses the aircraft's projected position O on the ground as its origin, with the horizontal ground axis as the x-axis and the vertical aircraft altitude axis as the y-axis. Coordinate system two is the ground projection coordinate system for the ring scan imaging. Within the L×W grid area monitored by the ring scan, select the vertex of grid one as its origin, with the length as the x-axis and the width as the y-axis. Set the outer diameter of the scanning ring to R and the inner diameter to r. See below for details. Figure 4 and Figure 5 As shown.

[0095] Step 2: Set five sets of parameters: thermal imager parameters, aircraft parameters, turntable parameters, target parameters, and scanning area, and initialize the parameters, such as... Figure 8 As shown, the following parameters are included: thermal imager pixel size u = 15 μm, number of pixels a × b = 640 × 512, integration time τ = 4 ms; aircraft speed v = 2.5 km / min, aircraft altitude H = 0.5 km, aircraft turning radius r′ = 0.2 km, revisit time T = 5 min from the discovery of a target within the grid to its revisit; target size M = 4 m, target imaging size n = 6 pixels, and rectangular scan area width W = 5 km.

[0096] Step 3: Calculate the inner diameter r of the scanning ring and the round-trip distance d of the aircraft.

[0097] The longest revisit time can be calculated as: T=(2d+πr′) / v.

[0098] To ensure no scans are missed, the following condition must be met: d ≥ 2r.

[0099] The revisit time is shortest when d = 2r, and the annulus is as follows: Figure 6 As shown.

[0100] Therefore, we obtain d = 2r = 5.94km.

[0101] Step 4: Calculate the focal length f of the thermal imager to ensure clear imaging under forward image shift during aircraft flight.

[0102] Considering the motion blur caused by aircraft speed, to achieve a clear image, the following must be met:

[0103]

[0104] Therefore, we get:

[0105]

[0106] Thermal imager focal length that meets minimum inner diameter requirements

[0107] Step 5: Calculate the maximum outer diameter R of the scanning ring.

[0108] To meet the requirements for the number of imaging pixels for detection and recognition, there are

[0109]

[0110] To ensure no scans are missed, R must also satisfy:

[0111]

[0112] Therefore, the maximum outer diameter of the ring band that meets the detection and recognition requirements at this focal length is obtained:

[0113]

[0114] Step Six: Calculate the area S′ of the rectangular region and the area S of the scanned region. For example... Figure 7 As shown, the rectangular area S′ is the area enclosed by the green rectangle, and the scanned area S is the area enclosed by the red outline.

[0115] Actual scanned area: S = πR 2 +2Rd=184.26km 2 ;

[0116] Area of ​​the inscribed rectangular region:

[0117] Length of the inscribed rectangle:

[0118] Step 7: Establish the functional relationship between the step scan pitch angle and the inner diameter of the ring band.

[0119] The calculated field of view angle β = 2arctan(u×b / 2f) = 4.06°;

[0120] Obtain the pitch angle

[0121] The theoretical pitch angle γ′2=γ1-β=3.47°;

[0122] outer diameter of the scanning ring at pitch angle γ1

[0123] outer diameter of the scanning ring at the theoretical pitch angle γ′2 R2 = 5.9986 km;

[0124] Pitch angle at R2

[0125] During the iterative calculation, based on the maximum outer diameter R of the scanning ring obtained in step five, if R1>R, then R1=R; otherwise, use the pitch angle γ1 to calculate R1. If R2>R, then R2=R; otherwise, use the pitch angle γ′2 to calculate R2. At the same time, if R2==R, then γ2 is the pitch angle at R2; otherwise, γ2=γ′2. If the judgment condition is met, the simulation ends.

[0126] Step 8: Calculate the instantaneous field of view angle α and the vertical resolution δ of the optical axis at the elevation angle γ. c Horizontal resolution δ of the optical axis s Minimum resolution vertical δ cmin Minimum resolution level δ smin Maximum resolution vertical δ cmax Maximum resolution level δ smax To measure the size of the target image in the circular scanning mode, we take γ = γ1 = 7.53°.

[0127] 1) Instantaneous field of view angle α (°):

[0128]

[0129] 2) Vertical resolution δ of the optical axis c (m):

[0130]

[0131] 3) Horizontal resolution δ of the optical axis s (m):

[0132]

[0133] 4) Minimum resolution vertical δ cmin (m):

[0134]

[0135] 5) Minimum resolution level δ smin (m):

[0136]

[0137] 6) Maximum resolution vertical δ cmax (m):

[0138]

[0139] 7) Maximum resolution level δ smax (m):

[0140]

[0141] It should be noted that if the parameter values ​​in one of the steps are changed, the new simulation results will be calculated using the changed values ​​as input parameters.

[0142] Through the description of specific embodiments, a more in-depth and specific understanding should be gained of the technical means and effects adopted by the present invention to achieve the intended purpose. However, the accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention.

Claims

1. A method for determining the parameters of an airborne optoelectronic system for target area reconnaissance, characterized in that, The parameters of the airborne optoelectronic system are determined using a simulation method, which includes: S10, Create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area; S20, setting parameters for the aircraft and the airborne optoelectronic system; S30, in the coordinate system, based on the set parameters, calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft; inner diameter of the scanning ring The round-trip distance d of the aircraft satisfies: Where T is the longest revisit time: v is the speed of the aircraft. S40, the turning radius of the aircraft; calculate the focal length of the thermal imager based on the requirements for clear imaging. ;in, S50: Integrating time, H is the aircraft altitude, and u is the thermal imager pixel size; S50: Based on the required number of imaging pixels and the focal length of the thermal imager, calculate the maximum outer diameter of the scanning ring. Where M is the target size and n is the target image size; S60, establish the functional relationship between the length and width of the rectangular scanning area, and calculate the area of ​​the rectangular target area and the area of ​​the scanning area; S70 performs iterative parameter optimization; Step S70 includes: S71, establish the functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation; S72, calculate the instantaneous field of view angle and the vertical resolution of the optical axis, the horizontal resolution of the optical axis, the minimum resolution vertical, the minimum resolution horizontal, the maximum resolution vertical, and the maximum resolution horizontal at the said pitch angle, so as to measure the target imaging size.

2. The method for determining the parameters of an airborne optoelectronic system for target area reconnaissance according to claim 1, characterized in that, The method further includes: S80, based on the reconnaissance mission and the area of ​​the obtained rectangular target region, determine the total number of aircraft.

3. The method for determining the parameters of an airborne optoelectronic system for target area reconnaissance according to claim 1, characterized in that, Step S10 specifically includes: Treating the airborne optoelectronic system and the aircraft as a single point, establish coordinate system one and coordinate system two. Coordinate system one takes the projection position of the aircraft on the ground as the origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate system two takes the vertex of the rectangular target area as the origin, the longer side as the x-axis, and the shorter side as the y-axis.

4. The method for determining the parameters of an airborne optoelectronic system for target area reconnaissance according to claim 1, characterized in that, In step S20, parameter settings include: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scan area width.

5. A parameter simulation system for an airborne optoelectronic system for target area reconnaissance, characterized in that, include: The coordinate system creation module is used to create a coordinate system based on the positional relationship between the airborne optoelectronic system and the target area. The parameter setting module is used to set parameters for the aircraft and the airborne optoelectronic system; The calculation module is used to calculate the inner diameter of the scanning ring and the round-trip distance of the aircraft based on set parameters in the coordinate system; the inner diameter of the scanning ring... The round-trip distance d of the aircraft satisfies: Where T is the longest revisit time: v is the speed of the aircraft. The turning radius of the aircraft; Calculate the focal length of the thermal imager based on the requirements for clear imaging. ;in, Where H is the integration time, H is the aircraft altitude, and u is the thermal imager pixel size; Based on the required number of imaging pixels and the focal length of the thermal imager, the maximum outer diameter of the scanning ring is calculated. Where M is the target size and n is the target image size; Establish a functional relationship between the length and width of the rectangular scanning region, and calculate the area of ​​the rectangular target region and the area of ​​the scanning region; The iterative optimization module is used to perform iterative optimization of parameters; The iterative optimization module is specifically used for: Establish a functional relationship between the step scan pitch angle and the inner diameter of the ring belt, and determine the pitch angle through iterative calculation; The instantaneous field of view angle and the vertical resolution, horizontal resolution, minimum resolution vertical, minimum resolution horizontal, maximum resolution vertical, and maximum resolution horizontal at the pitch angle are calculated to measure the target imaging size.

6. The airborne optoelectronic system parameter simulation system for target area reconnaissance according to claim 5, characterized in that, The coordinate system creation module is specifically used for: Treating the airborne optoelectronic system and the aircraft as a single point, establish coordinate system one and coordinate system two. Coordinate system one takes the projection position of the aircraft on the ground as the origin, the horizontal axis of the ground as the x-axis, and the vertical axis of the aircraft's altitude as the y-axis. Coordinate system two takes the vertex of the rectangular target area as the origin, the longer side as the x-axis, and the shorter side as the y-axis.

7. The airborne optoelectronic system parameter simulation system for target area reconnaissance according to claim 5, characterized in that, The parameter setting module performs parameter settings including: assigning initial values ​​to revisit time, aircraft speed, aircraft turning radius, aircraft altitude, thermal imager pixel size, number of pixels, integration time, target size, target imaging size, and rectangular scan area width.

8. The airborne optoelectronic system parameter simulation system for target area reconnaissance according to claim 5, characterized in that, The simulation system also includes: The determination module is used to determine the total number of aircraft based on the area of ​​the rectangular target region obtained from the reconnaissance mission.

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