JP2017166993A - Arithmetic device, control device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the MTF degradation of a photograph image due to footprint distortion even when line rates are the same in the whole of an optical sensor in an observation device that photographs a photograph object by scanning with the optical sensor.SOLUTION: A normal vector distance computation unit 110 of an arithmetic unit 10 calculates the distance from the observation device 1 to a sensor viewpoint and a normal vector that defines the tangential plane of the ground surface at the sensor viewpoint on the basis of the posture and position of an observation device 1 that photographs a ground surface by scanning with an optical sensor mounted in a flying object. A target posture angular velocity computation unit 120 calculates, on the basis of the position, speed and posture of the observation device 1, a line rate, the distance from the observation device 1 to the viewpoint, and the normal vector, a target posture angular velocity such that an error between a tangential plane mapped vector in which a vector for one pixel of the optical sensor in the scanning direction is mapped to the tangential plane in the optical system of the observation device 1 and a tangential plane movement vector that indicates movement of the sensor viewpoint on the tangential plane at a line rate per pixel is minimal.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an arithmetic device, a control device, and a program for calculating a target posture angular velocity of an observer that images an imaging target by scanning with an optical sensor mounted on a flying object.

  There is an observation device that is mounted on a flying object such as an artificial satellite or an aircraft and that observes an imaging target using an optical sensor such as a TDI (Time Delay and Integration) type CCD (Charge Coupled Device). Hereinafter, the direction in which the photoelectric conversion element of the optical sensor included in such an observation device faces the imaging target is referred to as a sensor viewing direction, and the point where the sensor viewing direction intersects the surface of the imaging target (hereinafter referred to as the imaging surface) is referred to as the sensor viewpoint. That's it. When observing an imaging target by scanning using an optical sensor such as a TDI type CCD, an optical system of an observer is used on the imaging surface with a vector in the scanning direction (AT direction: Along Track direction) for one pixel of the CCD. It is preferable that the mapping vector mapped in step 1 and the movement vector indicating movement on the imaging surface of the sensor viewpoint at the line rate per pixel (integration time for storing the optical signal in each pixel) are matched as much as possible. This is because, when there is a difference between these vectors, the MTF (Modulation Transfer Function) of the captured image is degraded according to the magnitude of the difference. Therefore, it is necessary to perform observation by appropriately setting the angular velocity of the observer and the line rate of the optical sensor according to the mapping vector and the movement vector.

  Patent Document 1 discloses an imaging apparatus that suppresses variation in image sharpness due to a difference in a light receiving direction for each photoelectric conversion element when imaging is performed by scanning an imaging target in a scanning direction. In the imaging device described in Patent Document 1, different line rates are set for each block of a TDI type CCD according to GSD (Ground Sampling Distance).

JP 2011-24167 A

  When observation is performed by tilting the sensor line-of-sight direction at the center of the visual field of an observation device that observes an imaging target using an optical sensor such as a TDI type CCD from the vertical direction, a mapping on the imaging surface of the entire optical sensor (hereinafter referred to as foot). Is called a trapezoidal shape. For this reason, the optimum line rate is different between the front side and the back side of the optical sensor, and when the same line rate is set for the entire optical sensor, the MTF at the field angle end deteriorates. When the photoelectric conversion element provided in the observation device is configured as described in Patent Document 1, an optimal line rate is set for the entire optical sensor by setting an appropriate line rate for each part such as the front side or the back side of the sensor. There is a possibility that the error from the rate can be kept small. However, in such a configuration, the influence of noise generated in the drive circuit portion is large, and the drive circuit becomes complicated and large, so that it is difficult to realize.

  The present invention has been made in view of the above-described circumstances, and in an observation device that captures an imaging target by scanning with an optical sensor, even if the line rate is the same for the entire optical sensor, distortion of the footprint is caused. An object of the present invention is to suppress the MTF deterioration of the captured image due to the above.

  In order to achieve the above object, an arithmetic device according to the present invention is an arithmetic device that calculates a target attitude angular velocity of an observer that images an imaging target by being mounted on a flying object and scanning with an optical sensor. The computing device includes a normal vector distance computing unit and a target posture angular velocity computing unit. The normal vector distance calculation unit intersects the imaging surface where the sensor line-of-sight direction, from which the photoelectric conversion element of the optical sensor faces the imaging object, is the surface of the imaging object, based on the attitude of the observer and the position of the observer A normal vector defining the distance to the sensor viewpoint and the tangent plane of the imaging surface at the sensor viewpoint is calculated. The target attitude angular velocity calculator is the position of the observer, the velocity of the observer, the attitude of the observer and the line rate of the optical sensor, the distance from the observer to the sensor viewpoint calculated by the normal vector distance calculator, and the normal Based on the normal vector calculated by the vector distance calculation unit, the vector in the scanning direction of one pixel of the optical sensor is mapped to the tangent plane by the optical system of the observer, and the line rate per pixel A target posture angular velocity at which an error from the tangential plane movement vector indicating the movement of the sensor viewpoint on the tangential plane is minimized with a predetermined calculation accuracy is calculated.

  According to the present invention, in an observer that images an object to be imaged by scanning with an optical sensor, a vector in the scanning direction for one pixel of the optical sensor is mapped to the tangential plane of the imaging surface at the sensor viewpoint by the optical system of the observer. By calculating a target posture angular velocity at which an error between the tangential plane mapping vector and the movement vector indicating movement on the imaging surface of the sensor viewpoint at the line rate of the optical sensor per pixel is minimized with a predetermined calculation accuracy, Even if the line rate is the same for the entire optical sensor, it is possible to suppress MTF degradation of the captured image due to footprint distortion.

It is a figure which shows an example of the footprint of the observer based on Embodiment 1 of this invention. It is a figure which shows the relationship between the mapping vector which concerns on Embodiment 1, a movement vector, and an error vector. It is a figure which shows the example in the case where it is set as the same line rate in the whole optical sensor, and the observer moves by the suitable attitude | position angular velocity when the viewpoint in a sensor center moves linearly. FIG. 3 is a diagram illustrating a functional configuration example of a control device according to the first embodiment. 6 is a diagram illustrating a functional configuration example of a normal vector distance calculation unit according to Embodiment 1. FIG. 3 is a diagram illustrating an example of a functional configuration of a target posture angular velocity calculation unit according to Embodiment 1. FIG. It is a figure which shows the function structural example of the control apparatus which concerns on Embodiment 4 of this invention. It is a block diagram which shows an example of the hardware constitutions of the arithmetic unit which concerns on embodiment of this invention.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail with reference to drawings. In addition, the same code | symbol is attached | subjected to the part which is the same or it corresponds in a figure. In this embodiment, an example in which a TDI CCD is used as an optical sensor and the ground surface is observed as an imaging target will be described.

(Embodiment 1)
FIG. 1 is a diagram showing an example of the footprint of an observer according to Embodiment 1 of the present invention. The observation device 1 is mounted on an artificial satellite, an aircraft, or the like, and observes the ground surface with a TDI type CCD. As shown in FIG. 1, when observation is performed by tilting the sensor line-of-sight direction at the center of the visual field of the observation device 1 from the vertical direction, the footprint 140 of the observation device 1 is distorted into a trapezoidal shape. For this reason, the optimal line rate differs depending on the optical sensor, and the optical sensor has the same line rate, and the viewpoint at the center of the optical sensor (hereinafter referred to as the sensor center) moves linearly. As a result, the MTF at the corner end deteriorates.

  FIG. 2 is a diagram illustrating a relationship among the mapping vector, the movement vector, and the error vector according to the first embodiment. The mapping vector V1 is a vector obtained by mapping a vector in the scanning direction for one pixel of the CCD onto the ground surface by the optical system of the observation device 1. The movement vector V2 is a vector indicating the movement of the sensor viewpoint on the ground surface at the line rate per pixel. The error vector V3 is a vector indicating an error between the mapping vector V1 and the movement vector V2. In order to reduce the degradation of the MTF of the captured image, it is necessary to reduce the error vector V3.

  FIG. 3 is a diagram illustrating an example of the case where the optical sensor has the same line rate and the viewpoint at the center of the sensor moves linearly and the observer is driven at an appropriate posture angular velocity. FIG. 3A shows a case where the viewpoint at the center of the sensor moves linearly. If the footprint 140 is trapezoidal and the viewpoint at the center of the sensor moves in a straight line, the mapping vector V1 and the movement vector V2 match before and behind the sensor, assuming the same line rate for the entire optical sensor. As a result, the MTF of the captured image deteriorates. FIG. 3B shows a case where the observer 1 is driven at an appropriate posture angular velocity. As shown in FIG. 3B, the distribution of the movement vector V2 can be shaped by driving the observer 1 at an appropriate posture angular velocity. As a result, the error vector V3 of the entire field of view of the optical sensor is reduced, and the MTF deterioration of the captured image can be reduced.

  FIG. 4 is a diagram illustrating a functional configuration example of the control device according to the first embodiment. The control device 100 includes a calculation device 10 including a normal vector distance calculation unit 110 and a target posture angular velocity calculation unit 120, and a posture control unit 11. When the normal vector distance calculation unit 110 of the calculation device 10 acquires the attitude and position of the observation device 1 from the observation device 1, the distance between the observation device 1 and the sensor viewpoint (hereinafter referred to as the sensor viewpoint distance) and the ground at the sensor viewpoint. A normal vector from the surface (hereinafter referred to as a ground surface normal vector) is calculated and sent to the target posture angular velocity calculation unit 120.

  The target posture angular velocity calculation unit 120 acquires the posture, position, speed, and optical sensor line rate of the observation device 1 from the observer 1, and receives the sensor viewpoint distance and the ground surface normal vector from the normal vector distance calculation unit 110. Based on these, a target posture angular velocity that suppresses MTF deterioration of the captured image of the entire field of view of the optical sensor is calculated and sent to the posture control unit 11. The attitude control unit 11 acquires the attitude angle and attitude angular velocity from the observer 1, calculates the torque applied to the observer 1 so as to follow the target attitude angular velocity received from the target attitude angular velocity calculator 120, and outputs the torque to the observer 1 Then, the attitude of the observer 1 is controlled. Note that the attitude control of the observation device 1 performed by the attitude control unit 11 can be realized by existing techniques, and details thereof are omitted here. As the posture, position, velocity, posture angle, and posture angular velocity of the observation device 1, values measured or estimated in real time may be used, or planned values may be used. Here, a method in which the normal vector distance calculation unit 110 calculates the sensor viewpoint distance and the ground surface normal vector and a method in which the target posture angular velocity calculation unit 120 calculates the target posture angular velocity will be described with reference to FIGS. explain.

  FIG. 5 is a diagram illustrating a functional configuration example of the normal vector distance calculation unit according to the first embodiment. The normal vector distance calculation unit 110 includes a sensor viewpoint calculation unit 111, a distance calculation unit 112, and a normal direction calculation unit 113. The normal vector distance calculation unit 110 is given the position and orientation of the observer 1. The sensor viewpoint calculation unit 111 calculates the sensor line-of-sight direction from the attitude of the observation device 1 and sets the closest intersection of the sensor line-of-sight direction half line and the ground surface as the sensor viewpoint. The sensor viewpoint calculation unit 111 sends the sensor viewpoint to the distance calculation unit 112 and the normal direction calculation unit 113. The distance calculation unit 112 calculates a sensor viewpoint distance based on the position of the observation device 1 and the sensor viewpoint received from the sensor viewpoint calculation unit 111. The distance calculation unit 112 sends the sensor viewpoint distance to the target posture angular velocity calculation unit 120.

  The normal direction calculation unit 113 obtains a ground surface normal vector from the ground surface shape based on the sensor viewpoint received from the sensor viewpoint calculation unit 111. For example, when the ground surface is on a spherical surface, the vector from the center of the sphere toward the sensor viewpoint is the ground surface normal vector. When a digital elevation model (DEM) is used as the ground surface shape, the sensor viewpoint is first obtained numerically using the digital elevation model, and the elevation data in the vicinity of the sensor viewpoint is used to numerically calculate the ground surface. Calculate the surface normal vector. The ground surface normal vector defines a tangent plane of the ground surface at the sensor viewpoint (hereinafter referred to as a sensor viewpoint tangent plane). The normal direction calculation unit 113 sends the ground surface normal vector to the target posture angular velocity calculation unit 120.

  FIG. 6 is a diagram illustrating a functional configuration example of the target posture angular velocity calculation unit according to the first embodiment. The target posture angular velocity calculation unit 120 includes a linear simultaneous equation generation unit 121 and a least square solution calculation unit 122. The target posture angular velocity calculation unit 120 is provided with the position, velocity, posture and line rate of the optical sensor, the sensor viewpoint distance, and the ground surface normal vector. The linear simultaneous equation generation unit 121 maps the scanning direction vector for one pixel of the CCD to the sensor viewpoint tangent plane by the optical system of the observation device 1 based on the position, posture, and ground surface normal vector of the observation device 1. Find the tangential plane map vector. The tangential plane mapping vector is a vector obtained by projecting the mapping vector V1 onto the sensor viewpoint tangent plane. The arithmetic unit 10 stores the scanning direction of the observer 1. The linear simultaneous equation generation unit 121 uses the sensor 1 position, velocity, orientation, optical sensor line rate, sensor viewpoint distance and ground surface normal vector, and the sensor viewpoint sensor at the line rate per pixel. A tangential plane movement vector indicating movement in the viewpoint tangent plane is obtained. The linear simultaneous equation generation unit 121 sends the tangent plane mapping vector and the tangent plane movement vector to the least square solution calculation unit 122.

  The least square solution calculation unit 122 obtains an attitude angular velocity at which an error between the tangential plane mapping vector received from the linear simultaneous equation generation unit 121 and the tangential plane movement vector is minimized in the entire visual field of the optical sensor by the least square method, The target posture angular velocity is used. The tangential plane mapping vector and the tangential plane movement vector are expressed by linear simultaneous equations. In other words, the least square solution calculation unit 122 calculates a posture angular velocity at which the error of the linear simultaneous equations representing the tangential plane mapping vector and the tangential plane movement vector is minimized in the entire visual field of the optical sensor as the target posture angular velocity. Since the tangential plane motion vector is a linear vector function with respect to the attitude angular velocity, the least square solution can be obtained quickly and reliably by using a pseudo inverse matrix of the coefficient matrix.

  As described above, according to the control device 100 of the first embodiment, the observer 1 that images the ground surface by scanning with the optical sensor calculates the target posture angular velocity according to the distortion of the footprint 140. Even if the line rate is the same for the entire optical sensor, the MTF deterioration of the entire field of view due to the distortion of the footprint 140 can be suppressed.

  Since the mapping vector V1 of all the photoelectric conversion elements of the optical sensor forms the footprint 140, the target posture is determined according to the distortion of the footprint 140 by using the tangential plane mapping vector obtained by projecting the mapping vector V1 onto the sensor viewpoint tangent plane. Angular velocity can be calculated. As a result, regardless of the shape of the footprint 140, optimal posture movement can be realized over the entire visual field of the optical sensor, and MTF deterioration can be suppressed over the entire captured image. In addition, every time various data is acquired from the observation device 1, the algorithm calculates the target posture angular velocity that minimizes the error between the tangential plane mapping vector and the tangential plane movement vector of the entire field of view of the optical sensor. The trajectory of the sensor viewpoint that minimizes the MTF degradation can be flexibly realized. Furthermore, since it is not necessary to plan the trajectory of the sensor viewpoint in advance, observation with small MTF degradation can be started at any time. As a result, the ground surface can be quickly imaged in an emergency such as a disaster.

(Embodiment 2)
The configuration of the control device of the observation device 1 according to the second embodiment is the same as that of the first embodiment, but the second embodiment differs in the method for calculating the target posture angular velocity in the target posture angular velocity calculator 120.
The target posture angular velocity calculation unit 120 in the first embodiment is configured such that the error between the tangential plane mapping vector and the tangential plane movement vector is minimized over the entire visual field of the optical sensor. However, when observing with a TDI type CCD, MTF degradation in a specific direction may be particularly important. Therefore, in the second embodiment, a target attitude angular velocity that minimizes an error in a specific direction in which MTF deterioration is to be suppressed is calculated, not an error in consideration of all directions of the vector. A specific method is as follows.

  The least square solution calculation unit 122 of the target attitude angular velocity calculation unit 120 of the control device 100 is a vector in a direction in which MTF degradation is to be suppressed with respect to the tangential plane mapping vector and the tangential plane movement vector received from the linear simultaneous equation generation unit 121. The target attitude angular velocity at which the error is minimized in the entire field of view of the optical sensor is obtained by the least square method. Even in such a case, since a group of linear simultaneous equations is obtained with respect to the target posture angular velocity, the least squares solution can be obtained quickly and reliably. Other configurations are the same as those in the first embodiment.

  As described above, according to the control device 100 of the second embodiment, the observer 1 that images the ground surface by scanning with the optical sensor calculates the target posture angular velocity according to the distortion of the footprint 140. Even if the line rate is the same for the entire optical sensor, it is possible to suppress MTF degradation in a specific direction due to distortion of the footprint 140.

(Embodiment 3)
The configuration of the control device 100 of the observation device 1 according to the third embodiment is the same as that of the first and second embodiments, but the target posture angular velocity calculation unit 120 differs in the method of calculating the target posture angular velocity in the third embodiment. In the first and second embodiments, the target posture angular velocity that suppresses the entire visual field of the optical sensor or MTF deterioration in one specific direction is calculated. However, the most important point in normal observation is generally designed to perform observation at the center of the visual field of the optical sensor. In Embodiments 1 and 2, it cannot be guaranteed that the error in the photoelectric conversion element at the center of the visual field is zero. Therefore, in the third embodiment, the target attitude angular velocity that minimizes the error in the photoelectric conversion element at the center of the visual field of the optical sensor and minimizes the error in the entire visual field is calculated. A specific method is as follows.

  The least square solution calculation unit 122 of the target attitude angular velocity calculation unit 120 of the control apparatus 100 first applies a photoelectric conversion element at the center of the visual field to the tangential plane mapping vector V1 ′ and the tangential plane movement vector V2 ′ received from the linear simultaneous equation generation unit 121. The linear simultaneous equations in which the tangent plane mapping vector V1 ′ and the tangential plane movement vector V2 ′ in FIG. Thereby, 2 degrees of freedom are uniquely determined among the target posture angular velocities having 3 degrees of freedom. For example, when the time differential of 1-2-3 Euler angles (roll angle, pitch angle, yaw angle) is used for the angular velocity expression, the linear simultaneous equations at the center of the visual field do not depend on the yaw rate. Therefore, the roll rate and the pitch rate can be uniquely determined. The least square solution calculation unit 122 obtains a target attitude angular velocity that minimizes the tangential plane error vector V3 'in the entire field of view of the optical sensor with the remaining one degree of freedom by the least square method. At this time, as in the second embodiment, the least square solution calculation unit 122 may obtain the target attitude angular velocity that minimizes the error of the inner product with the vector in the direction in which the error is desired to be reduced by the least square method. . Even in such a case, since a group of linear simultaneous equations is obtained with respect to the target posture angular velocity, the least squares solution can be obtained quickly and reliably. Other configurations are the same as those in the first and second embodiments.

  As described above, according to the control device 100 of the third embodiment, the observer 1 that images the ground surface by scanning with the optical sensor calculates the target posture angular velocity according to the distortion of the footprint 140. Even if the line rate is the same for the entire optical sensor, it is possible to prevent MTF degradation at the center of the visual field due to distortion of the footprint 140, and to suppress MTF degradation in the entire visual field or in a specific direction.

(Embodiment 4)
FIG. 7 is a diagram illustrating a functional configuration example of the control device according to the fourth embodiment of the present invention. The control device 100 according to the fourth embodiment is different from the control device 100 according to the first to third embodiments in the functional configuration of the arithmetic device 10. The arithmetic device 10 according to the fourth embodiment includes a target attitude angle calculator 130 in addition to the normal vector distance calculator 110 and the target attitude angular velocity calculator 120 included in the arithmetic devices 10 according to the first to third embodiments. When the normal vector distance calculation unit 110 acquires the attitude and position of the observer 1 from the observer 1, the normal vector distance calculation unit 110 calculates the sensor viewpoint distance and the ground surface normal vector, and sends them to the target attitude angular velocity calculation unit 120. The target posture angular velocity calculation unit 120 acquires the posture, position, speed, and optical sensor line rate of the observation device 1 from the observer 1, and receives the sensor viewpoint distance and the ground surface normal vector from the normal vector distance calculation unit 110. Then, the target posture angular velocity that suppresses the MTF deterioration of the captured image of the optical sensor is calculated and sent to the target posture angle calculation unit 130.

  Upon receiving the target posture angular velocity from the target posture angular velocity calculating unit 120, the target posture angle calculating unit 130 calculates a target posture angle at the next time by time integration. For the time integration, for example, the Euler method or the Runge-Kutta method may be used. The target posture angle calculation unit 130 outputs the target posture angular velocity and the target posture angle to the posture control unit 11 of the control device 100. The posture control unit 11 controls the posture angle and the posture angular velocity of the observation device 1 to be the target posture angle and the target posture angular velocity received from the target posture angle calculation unit 130, respectively. Further, the target posture angle calculation unit 130 may feed back the target posture angle to the normal vector distance calculation unit 110. Other configurations are the same as those in the first to third embodiments.

  As described above, according to the control device 100 of the fourth embodiment, the observer 1 that images the ground surface by scanning with the optical sensor calculates the target posture angular velocity according to the distortion of the footprint 140. Even if the optical sensor has the same line rate, it is possible to suppress the MTF deterioration of the captured image due to the distortion of the footprint 140. In addition, it is possible to obtain the target posture angle and the target posture angular velocity planned values to be taken by the observer 1 at high speed when the position, velocity and attitude of the observer 1 at a certain time are given. Further, when the plan value is approximated with a small number of parameters, the amount of information transferred to the observer 1 can be suppressed, and there is an effect that the transfer time can be shortened and the required memory can be reduced.

  In the above embodiment, the target attitude angular velocity at which the tangential plane error vector V3 ′ indicating the error between the tangential plane mapping vector V1 ′ and the tangential plane movement vector V2 ′ is minimized is obtained using the least square method. For example, the maximum likelihood method may be used, or the Newton method may be used. Alternatively, a target posture angular velocity at which an error vector V3 indicating an error between the mapping vector V1 and the movement vector V2 is minimized may be obtained. The minimum in the present invention is the minimum with a predetermined calculation accuracy. When the least square method or the maximum likelihood method is used, it is the minimum in the calculation accuracy of the least square method or the maximum likelihood method. When the Newton method is used, for example, the minimum is determined when the difference from the previous calculation result converges below a predetermined threshold.

  FIG. 8 is a block diagram showing an example of a hardware configuration of the arithmetic device according to the embodiment of the present invention. As shown in FIG. 8, the arithmetic device 10 includes a control unit 31, a main storage unit 32, an external storage unit 33, an operation unit 34, a display unit 35, and an input / output unit 36. The main storage unit 32, the external storage unit 33, the operation unit 34, the display unit 35, and the input / output unit 36 are all connected to the control unit 31 via the internal bus 30.

  The control unit 31 includes a CPU (Central Processing Unit) and the like. Each process of the normal vector distance calculation unit 110 and the target posture angular velocity calculation unit 120 of the calculation device 10 is performed according to a control program 39 stored in the external storage unit 33. Execute.

  The main storage unit 32 is composed of a RAM (Random-Access Memory) or the like, loads a control program 39 stored in the external storage unit 33, and is used as a work area of the control unit 31.

  The external storage unit 33 includes a nonvolatile memory such as a flash memory, a hard disk, a DVD-RAM, and a DVD-RW, and stores in advance a program for causing the control unit 31 to perform the processing of the arithmetic device 10, and also performs control. According to the instruction of the unit 31, the data stored by this program is supplied to the control unit 31, and the data supplied from the control unit 31 is stored.

  The operation unit 34 includes a pointing device such as a keyboard and a mouse, and an interface device that connects the keyboard and the pointing device to the internal bus 30. When the user inputs information to the arithmetic device 10, the input information is supplied to the control unit 31 via the operation unit 34.

  The display unit 35 is composed of a CRT or LCD. When the user inputs information to the arithmetic device 10, an operation screen is displayed.

  The input / output unit 36 includes a serial interface or a parallel interface. The input / output unit 36 is connected to the observer 1 and the attitude control unit 11. The input / output unit 36 functions as a normal vector distance calculation unit 110 and a target posture angular velocity calculation unit 120.

  In the processing of the normal vector distance calculation unit 110 and the target posture angular velocity calculation unit 120 of the calculation device 10 shown in FIG. 4, the control program 39 includes a control unit 31, a main storage unit 32, an external storage unit 33, an operation unit 34, and a display. The processing is executed by using the unit 35 and the input / output unit 36 as resources.

  In addition, the hardware configuration and the flowchart described above are merely examples, and can be arbitrarily changed and modified.

  A central part that performs processing of the arithmetic device 10 composed of the control unit 31, the main storage unit 32, the external storage unit 33, the operation unit 34, the display unit 35, the input / output unit 36, the internal bus 30, and the like is dedicated. Regardless of the system, it can be realized using a normal computer system. For example, a computer program for executing the above operation is stored and distributed on a computer-readable recording medium (flexible disk, CD-ROM, DVD-ROM, etc.), and the computer program is installed in the computer. Thus, the arithmetic device 10 that executes the above-described processing may be configured. Further, the computing device 10 may be configured by storing the computer program in a storage device included in a server device on a communication network such as the Internet and downloading it by a normal computer system.

  Further, when the functions of the arithmetic device 10 are realized by sharing of an OS (operating system) and an application program, or by cooperation between the OS and the application program, only the application program portion is stored in a recording medium or a storage device. May be.

  It is also possible to superimpose a computer program on a carrier wave and provide it via a communication network. For example, a computer program may be posted on a bulletin board (BBS, Bulletin Board System) on a communication network, and the computer program may be provided via the network. And you may comprise so that the process of the arithmetic unit 10 can be performed by starting this computer program and performing similarly to another application program under control of OS.

  DESCRIPTION OF SYMBOLS 1 Observation device, 10 arithmetic units, 11 Attitude control part, 30 Internal bus, 31 Control part, 32 Main memory part, 33 External storage part, 34 Operation part, 35 Display part, 36 Input / output part, 39 Control program, 100 Control 110, normal vector distance calculation unit, 111 sensor viewpoint calculation unit, 112 distance calculation unit, 113 normal direction calculation unit, 120 target posture angular velocity calculation unit, 121 linear simultaneous equation generation unit, 122 least squares solution calculation unit, 130 Target posture angle calculation unit, 140 footprint, V1 mapping vector, V2 movement vector, V3 error vector, V1 ′ tangential plane mapping vector, V2 ′ tangential plane movement vector, V3 ′ tangential plane error vector.

Claims (8)

An arithmetic device that calculates a target posture angular velocity of an observer that images an imaging target by scanning with an optical sensor mounted on a flying object,
The arithmetic unit is
Based on the attitude of the observer and the position of the observer, a sensor viewpoint in which a sensor line-of-sight direction in which the photoelectric conversion element of the optical sensor faces the imaging object from the observer intersects an imaging surface that is the surface of the imaging object A normal vector distance calculation unit that calculates a normal vector that defines a distance to and a tangent plane of the imaging surface at the sensor viewpoint;
The position of the observer, the speed of the observer, the attitude of the observer, the line rate of the optical sensor, the distance from the observer to the sensor viewpoint calculated by the normal vector distance calculation unit, and the method Based on the normal vector calculated by the line vector distance calculating unit, a tangential plane mapping vector obtained by mapping a vector in the scanning direction of one pixel of the optical sensor onto the tangent plane by the optical system of the observer, and one pixel A target posture angular velocity calculation unit that calculates the target posture angular velocity at which an error with a tangential plane movement vector indicating movement on the tangential plane of the sensor viewpoint at the perimeter line rate is minimized with a predetermined calculation accuracy;
An arithmetic device comprising:   2. The arithmetic device according to claim 1, wherein the target posture angular velocity calculation unit calculates a posture angular velocity that minimizes a square of an error of a linear simultaneous equation representing the tangential plane mapping vector and the tangential plane movement vector as the target posture angular velocity. .   The target attitude angular velocity calculation unit sets an error of the linear simultaneous equation of the photoelectric conversion element at the center of the visual field of the optical sensor in the linear simultaneous equations to 0, and the linear simultaneous equations of the other photoelectric conversion elements. The computing device according to claim 2, wherein a posture angular velocity that minimizes a square of an error in the equation is calculated as the target posture angular velocity. An arithmetic device that calculates a target posture angular velocity of an observer that images an imaging target by scanning with an optical sensor mounted on a flying object,
The arithmetic unit is
Based on the attitude of the observer and the position of the observer, a sensor viewpoint in which a sensor line-of-sight direction in which the photoelectric conversion element of the optical sensor faces the imaging object from the observer intersects an imaging surface that is the surface of the imaging object A normal vector distance calculation unit that calculates a normal vector that defines a distance to and a tangent plane of the imaging surface at the sensor viewpoint;
The position of the observer, the speed of the observer, the attitude of the observer, the line rate of the optical sensor, the distance from the observer to the sensor viewpoint calculated by the normal vector distance calculation unit, and the method Based on the normal vector calculated by the line vector distance calculation unit, a mapping vector obtained by mapping a vector in the scanning direction of one pixel of the optical sensor onto the imaging surface by the optical system of the observer, and A target posture angular velocity calculation unit that calculates the target posture angular velocity at which an error from a movement vector indicating movement of the sensor viewpoint on the imaging surface at the line rate is minimized with a predetermined calculation accuracy;
An arithmetic device comprising:   5. The arithmetic device according to claim 1, further comprising a target posture angle calculation unit that calculates a target posture angle of the observer based on the target posture angular velocity calculated by the target posture angular velocity calculation unit. . An arithmetic device according to claim 5;
An attitude control unit for controlling the attitude angle and attitude angular velocity of the observer to the target attitude angle and the target attitude angular velocity, respectively;
A control device comprising: A photoelectric conversion element of the optical sensor is directed from the observer to the imaging object based on the attitude of the observation apparatus that images the imaging object by mounting the computer on the flying object and scanning with the optical sensor. A normal vector distance calculation unit for calculating a normal vector defining a distance to a sensor viewpoint intersecting with an imaging surface whose sensor line-of-sight direction is the surface of the imaging target, and a tangent plane of the imaging surface at the sensor viewpoint; and
The position of the observer, the speed of the observer, the attitude of the observer, the line rate of the optical sensor, the distance from the observer to the sensor viewpoint calculated by the normal vector distance calculation unit, and the method Based on the normal vector calculated by the line vector distance calculating unit, a tangential plane mapping vector obtained by mapping a vector in the scanning direction of one pixel of the optical sensor onto the tangent plane by the optical system of the observer, and one pixel A target attitude angular velocity calculation unit for calculating a target attitude angular velocity of the observer that minimizes an error from a tangential plane movement vector indicating movement of the sensor viewpoint on the tangential plane at the perimeter line rate with a predetermined calculation accuracy ,
Program to function as. A photoelectric conversion element of the optical sensor is directed from the observer to the imaging object based on the attitude of the observation apparatus that images the imaging object by mounting the computer on the flying object and scanning with the optical sensor. A normal vector distance calculation unit for calculating a normal vector defining a distance to a sensor viewpoint intersecting with an imaging surface whose sensor line-of-sight direction is the surface of the imaging target, and a tangent plane of the imaging surface at the sensor viewpoint; and
The position of the observer, the speed of the observer, the attitude of the observer, the line rate of the optical sensor, the distance from the observer to the sensor viewpoint calculated by the normal vector distance calculation unit, and the method Based on the normal vector calculated by the line vector distance calculation unit, a mapping vector obtained by mapping a vector in the scanning direction of one pixel of the optical sensor onto the imaging surface by the optical system of the observer, and A target posture angular velocity calculation unit for calculating a target posture angular velocity of the observer that minimizes an error from a movement vector indicating movement of the sensor viewpoint on the imaging surface at the line rate with a predetermined calculation accuracy;
Program to function as.

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