Celestial body tracking system, celestial body tracking method, and program

Abstract

To provide a technology capable of tracking a celestial body with high precision without simultaneously performing measurement by a geomagnetic sensor and driving by an actuator. [Solution] A celestial body tracking system (100) includes at least one processor (31) and an imaging device (10), in which the processor executes an acquisition process for acquiring celestial body information, position information, and time information, and a tracking command process for issuing to the imaging device a change in the imaging direction in accordance with changes in the celestial body direction over time.

Description

[Technical Field]

[0001] The present invention relates to a celestial body tracking system, a celestial body tracking method, and a program. [Background technology]

[0002] When photographing celestial bodies from Earth using a camera fixed to a tripod, the celestial body appears to move due to the Earth's rotation, so if the camera is exposed for a long time, the celestial body will not appear as a point image. In order to capture a point image of a celestial body, it is common to use an equatorial mount to track the celestial body while taking the photograph. However, equatorial mounts are not only expensive, but also have the disadvantage of taking time to align the axis before use, and being heavy and difficult to carry.

[0003] A known method for photographing a celestial body while tracking it without using an equatorial mount is the technology described in Patent Document 1. Patent Document 1 discloses a tracking device equipped with a calculation unit that calculates the direction and speed at which a subject image moves relative to an imaging element, and a tracking control unit that drives and controls an image stabilization unit based on the calculation results to track the subject image so that it is always located at a predetermined position within the effective imaging area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-173343 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology of Patent Document 1 uses a geomagnetic sensor to measure the shooting direction (azimuth angle). The technology of Patent Document 1 has the problem that when an actuator is used to drive the vibration isolation unit to track a celestial body, a magnetic field is generated around the actuator, which reduces the measurement accuracy of the geomagnetic sensor and therefore reduces the accuracy of tracking the celestial body.

[0006] An object of one aspect of the present invention is to provide a technology that can track a celestial body with high accuracy without simultaneously performing measurement by a geomagnetic sensor and driving by an actuator. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, a celestial body tracking system according to one embodiment of the present invention is a celestial body tracking system for photographing a celestial body while tracking it, the celestial body tracking system including at least one processor and an imaging device, wherein the at least one processor executes an acquisition process for acquiring celestial body information representing the celestial body that is the subject, position information representing the imaging position, and time information representing the imaging time, and a tracking command process for issuing to the imaging device, based on the celestial body information, the position information, and the time information, a change in the imaging direction, which is the direction in which the imaging device takes images, in line with changes over time in the celestial body direction, which is the direction from the imaging position toward the celestial body.

[0008] Furthermore, in order to solve the above-mentioned problems, a celestial body tracking method according to one aspect of the present invention is a celestial body tracking method for photographing a celestial body while tracking it, characterized in that it includes acquiring celestial body information representing the celestial body that is the subject, position information representing the photographing position, and time information representing the photographing time, and, based on the celestial body information, position information, and time information, causing an imaging device to change the photographing direction, which is the direction in which the imaging device photographs, in line with changes over time in the celestial body direction, which is the direction from the photographing position toward the celestial body.

[0009] In addition, in order to solve the above-mentioned problems, a program according to one aspect of the present invention is a celestial body tracking system for photographing a celestial body while tracking it, the program being for controlling the celestial body tracking system including at least one processor and an imaging device, and characterized in that it causes the at least one processor to execute an acquisition process for acquiring celestial body information representing the celestial body that is the subject, position information representing the imaging position, and time information representing the imaging time, and a tracking command process for causing the imaging device to change the imaging direction, which is the direction in which the imaging device takes images, in accordance with changes over time in the celestial body direction, which is the direction from the imaging position toward the celestial body. [Effects of the Invention]

[0010] According to one aspect of the present invention, a celestial body can be tracked with high precision without simultaneously performing measurement by a geomagnetic sensor and driving by an actuator. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing the configuration of a celestial body tracking system according to a first embodiment of the present invention. [Figure 2] 2 is a flowchart showing the flow of processing executed by each processor of the celestial body tracking system shown in FIG. [Figure 3] 3 is a flowchart showing the flow of each process included in the tracking command process shown in FIG. 2. [Figure 4] FIG. 4 is a diagram of the celestial sphere for explaining the celestial body direction determination process shown in FIG. 3. [Figure 5] 4 is a graph for explaining the drive amount calculation process shown in FIG. 3. [Figure 6] FIG. 10 is a block diagram showing the configuration of a celestial body tracking system according to a second embodiment of the present invention. [Figure 7] 7 is a flowchart showing the flow of processing executed by each processor of the celestial body tracking system shown in FIG. 6. [Figure 8] 8 is a flowchart showing the flow of each process included in the tracking command process shown in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0013] (Celestial Tracking System 100) The configuration of a celestial object tracking system 100 according to the first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the celestial object tracking system 100 according to the first embodiment of the present invention. The celestial object tracking system 100 is a system for photographing a celestial object while tracking it in order to preferably obtain a point image of the celestial object.

[0014] 1, the celestial body tracking system 100 includes a lens 10, a camera 20, and an operation terminal 30. The lens 10 is detachably attached to the camera 20, and functions as an imaging device for photographing celestial bodies.

[0015] In this specification, an imaging device refers to a device equipped with an optical system that focuses light rays from a subject for imaging, a device equipped with a component that generates the image, a movable device that adjusts the orientation of these devices, or any combination thereof. An example of a device equipped with an optical system is a lens barrel. An example of a device equipped with a component that generates the image is a digital camera body equipped with an image sensor as the component, and a film camera body. Examples of a movable device are a motorized pan head and a motorized gimbal.

[0016] The lens 10 and the operation terminal 30 are connected to each other via a communication means so that they can communicate with each other. In this embodiment, the lens 10 and the operation terminal 30 are connected via a USB (Universal Serial Bus) cable, which is a wired communication means, via the communication interface 12 of the lens 10 and the communication interface 36 of the operation terminal 30. Note that in the present invention, the communication means connecting the lens 10 and the operation terminal 30 is not limited to a wired communication means. The communication means may be any means capable of transmitting and receiving electronic data between the lens 10 and the operation terminal 30, and may be either a wired communication means or a wireless communication means. Furthermore, the communication means may directly or indirectly connect the lens 10 and the operation terminal 30. Examples of networks that may be present between the lens 10 and the operation terminal 30 include a LAN (Local Area Network) and mount communication of the camera 20.

[0017] (Lens 10) The lens 10 is configured to form a subject image on an imaging element 23 provided in the camera 20. In this embodiment, a lens barrel that is detachably attached to the camera 20 is used as the lens 10. As shown in FIG. 1 , the lens 10 includes a processor 11, a communication interface 12, a photographing optical system 13, a lens actuator 14, and an optical system sensor 15.

[0018] The processor 11 is configured to control the overall operation of the lens 10. The processor 11 mainly executes a control process S10 for the lens 10 by expanding and executing a control process program P10 stored in the memory of the lens 10 and receiving a command signal from the processor 31 of the operation terminal 30. In this embodiment, a CPU (Central Processing Unit) is used as the processor 11. The control process S10 executed by the processor 11 will be described later with reference to different drawings.

[0019] The communication interface 12 is configured to control transmission of various data from the lens 10 and reception of various data by the lens 10. In this embodiment, a USB interface is used as the communication interface 12.

[0020] The photographing optical system 13 is a group of optical elements arranged on the optical axis OA. As shown in Fig. 1, the photographing optical system 13 has an anti-vibration lens 131. In addition to the anti-vibration lens 131, the photographing optical system 13 also has a focus lens (not shown), a zoom lens (not shown), and a fixed lens (not shown) as optical element groups, and forms a subject image on the image sensor 23. The anti-vibration lens 131 can be driven by the lens actuator 14 in a plane perpendicular to the optical axis OA.

[0021] As will be described later, in this embodiment, the attitude angle of the lens 10 with respect to the ground is constant during shooting, and the directional relationship between the lens 10 and the celestial body being photographed changes over time due to the rotation of the Earth, etc. However, by driving the vibration-proof lens 131 in accordance with the change in the directional relationship over time, it is possible to adjust the position at which the celestial body image is formed on the image sensor 23 so that it remains constant. In this embodiment, the direction in which the camera 20 and lens 10 photograph, that is, the direction from the photographing position toward the light source of the light rays that form an image at a fixed point on the image sensor 23, is referred to as the photographing direction. In this embodiment, by driving the vibration-proof lens 131, the lens 10 can change the photographing direction within a range of approximately ±0.5° in both the azimuth angle and the elevation angle.

[0022] The lens actuator 14 is an actuator that drives a group of optical elements included in the photographing optical system 13. The lens actuator 14 has a lens driving circuit, and drives the vibration-proof lens 131 based on a control signal from the processor 11.

[0023] The optical system sensor 15 is a sensor that measures the current positions of the optical element group included in the photographing optical system 13. The optical system sensor 15 measures the current positions of the vibration-proof lens 131, the focus lens, and the zoom lens of the photographing optical system 13, and outputs the results to the processor 11.

[0024] (Camera 20) Camera 20 is configured to convert a subject image formed on an image sensor 23 into an image. In this embodiment, a camera body of a digital camera is used as camera 20. As shown in FIG. 1, camera 20 includes a processor 21, a release switch 22, an image sensor 23, and a memory 24.

[0025] The processor 21 is configured to control the overall operation of the camera 20. In this embodiment, a CPU is used as the processor 21. The processor 21 controls the image sensor 23 to take a photograph in accordance with the on / off state of the release switch 22. When the release switch 22 is on, the processor 21 causes the image sensor 23 to photoelectrically convert the subject image and transmit the photoelectrically converted signal to the processor 21. The processor 21 processes the photoelectrically converted signal received from the image sensor 23 to generate image data and writes the image data to the memory 24.

[0026] The release switch 22 is a switch that operates in conjunction with a release button and outputs its on / off state to the processor 21. The image sensor 23 is a photoelectric conversion element that is disposed near the position where the subject image is formed by the lens 10. In this embodiment, a CCD (Charge-Coupled Device) image sensor is used as the image sensor 23. The memory 24 is a recording medium having a rewritable nonvolatile memory, and stores image data generated by the processor 21. In this embodiment, the memory 24 is a memory card that is detachably attached to the camera 20.

[0027] In this embodiment, the camera 20 is fixed to a tripod installed at the shooting position, so that the attitude angle of the camera 20 and the lens 10 relative to the ground is constant during shooting.

[0028] (Operation terminal 30) The operation terminal 30 functions as an input device through which a user inputs various pieces of information referenced by the celestial body tracking system 100, and is configured to process the various pieces of information and control the entire celestial body tracking system 100. In this embodiment, a smartphone is used as the operation terminal 30. As shown in FIG. 1 , the operation terminal 30 is separate from the lens 10, and includes a processor 31, a memory 32, a touch display 33, a GNSS sensor 34, a clock 35, and a communication interface 36.

[0029] The processor 31 is a component for controlling the overall operation of the operation terminal 30. The processor 31 is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a combination thereof. The processor 31 mainly executes a control process S30 of the operation terminal 30 by expanding and executing a control processing program P30 stored in the memory 32 of the operation terminal 30. The control process S30 executed by the processor 31 will be described later with reference to different drawings.

[0030] The memory 32 is configured to store various information referenced in the control process S30 of the operation terminal 30. In this embodiment, the memory 32 includes a primary memory and a secondary memory. The primary memory volatilely stores celestial body information, position information, time information, and roll angle information. The secondary memory nonvolatilely stores the control process program P30. In this embodiment, a DRAM (Dynamic Random Access Memory) is used as the primary memory, and a flash memory is used as the secondary memory.

[0031] The touch display 33 is configured to display a UI (User Interface) for the user to input operations and to accept inputs from the user. In this embodiment, the touch display 33 is an electronic component that integrally combines a display that displays a UI for the user to input celestial body information and roll angle information, and a touch sensor that detects touch operations input by the user.

[0032] The GNSS sensor 34 is a sensor for a global navigation satellite system, measures the position (latitude and longitude) of the operation terminal 30 on the earth, and outputs the measurement result to the processor 31. In this embodiment, a GPS (Global Positioning system) sensor is used as the GNSS sensor 34. The clock 35 is configured to measure the current time and date, and in this embodiment, a clock circuit is used as the clock 35. The communication interface 36 is configured to control the transmission of various data from the operation terminal 30 and the reception of various data by the operation terminal 30. In this embodiment, a USB interface is used as the communication interface 36.

[0033] (Control process S100 of celestial body tracking system 100) The control process S100 of the celestial body tracking system 100 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the flow of processes executed by each processor of the celestial body tracking system 100 shown in Fig. 1. The control process S100 is a process for causing the lens 10 to change the shooting direction, which is the direction in which the lens 10 shoots an image, in accordance with changes over time in the celestial body direction, which is the direction from the shooting position toward the celestial body, based on celestial body information that indicates the celestial body that is the subject, position information that indicates the shooting position, and time information that indicates the shooting time.

[0034] As shown in Fig. 1, the control process S100 includes a control process S30 for the operation terminal 30 and a control process S10 for the lens 10. The processor 31 of the operation terminal 30 executes the control process S30 of the operation terminal 30, The processor 11 of the lens 10 executes the control process S10 in conjunction with the control process S30. This is carried out by:

[0035] (Control process S30 of operation terminal 30) The control process S30 of the operation terminal 30 will be described with reference to Fig. 2. The control process S30 is a process for causing the lens 10 to change the shooting direction in accordance with changes in the direction of the celestial body over time, based on celestial body information, position information, and time information. The control process S30 is mainly executed by the processor 31 of the operation terminal 30. As shown in Fig. 2, the control process S30 includes an input reception process S31, an acquisition process S32, and a tracking command process S33.

[0036] The input reception process S31 is a process in which the touch display 33 receives various pieces of information input by the user and transmits the information to the processor 31. In this embodiment, the touch display 33 receives celestial body information and roll angle information input by the user. When the processor 31 receives the various pieces of information received by the touch display 33, the processor 31 starts the acquisition process S32.

[0037] Celestial object information is information that describes a celestial object that is the subject of photography. In this specification, a celestial object may be a single star or a group of stars (e.g., a constellation or a galaxy). The celestial object information may describe the celestial object that is the subject of photography in various levels of detail. For example, the celestial object information may describe a single star, a group of stars, the time and direction at which the star is visible, or the equatorial or ecliptic coordinates of the celestial object. Examples of information describing a single star include the star's proper name, Bayer code, and number. Examples of information describing a group of stars include the name of a constellation or galaxy. Examples of information describing the time and direction at which a star is visible include a combination of time and direction, such as "winter night sky, south-southwest." A user may point the lens 10 toward the sky, check the celestial object captured in the viewfinder of the camera 20, and input information describing the celestial object as celestial object information. Alternatively, the user may input the celestial body information of the celestial body that the user wishes to photograph before pointing the lens 10 at the sky.

[0038] The roll angle information is information that represents the roll angle of the lens 10 around the shooting direction. The roll angle information may be a numerical value that represents the roll angle, or may be any information that corresponds to the numerical value of the roll angle. In this embodiment, the arbitrary information that corresponds to the numerical value of the roll angle is input as information indicating whether the orientation in which the camera 20 to which the lens 10 is attached is fixed to the tripod is vertical or horizontal, in other words, whether the camera 20 is fixed horizontally or vertically relative to the tripod. As an example, if the user inputs "vertical" as the roll angle information, the roll angle can be converted to 0°, and if the user inputs "horizontal," the roll angle can be converted to 90°.

[0039] In the acquisition process S32, the processor 31 acquires various pieces of information to be referenced in the tracking command process S33 from the various components of the celestial body tracking system 100. In this embodiment, the processor 31 acquires celestial body information that indicates the celestial body that is the subject, position information that indicates the shooting position, time information that indicates the shooting time, and roll angle information that indicates the roll angle. Once the processor 31 acquires the various pieces of information, the processor 31 starts the tracking command process S33.

[0040] The processor 31 acquires celestial object information received from the touch display 33 in an input reception process S31 as celestial object information. In this embodiment, if the acquired celestial object information does not represent a single star, the processor 31 executes a conversion process in an acquisition process S32 to convert the acquired celestial object information into celestial object information representing a single star that represents the celestial object represented by the celestial object information. The processor 31 may determine the single star that represents the celestial object based on the star's position, brightness, or a combination thereof. As an example, if the acquired celestial object information represents a constellation including multiple stars, the processor 31 converts the acquired celestial object information into celestial object information representing a single star located closest to the center of the constellation. As another example, if the acquired celestial object information represents a time and direction at which a star is visible, the processor 31 converts the acquired celestial object information into celestial object information representing the single brightest star at that time and in that direction. By executing the conversion process, the direction of the celestial object can be determined with higher accuracy in the subsequent tracking command process S33.

[0041] The location information is information that indicates the location of a photograph on Earth. Examples of location information include a combination of latitude and longitude, and the name of a land or building that can be converted into a combination of latitude and longitude. In this embodiment, the processor 31 acquires the latitude and longitude of the operation terminal 30 measured by the GNSS sensor 34 from the GNSS sensor 34 as the location information. It is preferable that the location information indicates the location of the photographing device (lens 10) itself. However, in this embodiment, the lens 10 and the operation terminal 30 are connected by wired communication means, and their positions on Earth are substantially the same, so the latitude and longitude of the operation terminal 30 can be used as the location information.

[0042] The time information is information that indicates the time of shooting and includes not only the time but also the date. In this embodiment, the processor 31 acquires the current time and date as the time information from the clock 35. Note that in this embodiment, upon receiving a command signal from the processor 31 of the operation terminal 30, the processor 11 of the lens 10 starts the tracking process S11 and immediately drives the vibration-proof lens 131. Therefore, the current time acquired by the processor 31 as time information is substantially equal to the tracking start time.

[0043] In an input reception process S31, the processor 31 acquires, as the roll angle information, roll angle information received from the touch display 33. If the acquired roll angle information is not a numerical value representing the roll angle, in an acquisition process S32, the processor 31 may execute a conversion process to convert the acquired roll angle information into a numerical value representing the roll angle.

[0044] The tracking command process S33 is a process in which the processor 31 causes the lens 10 to change the shooting direction, which is the direction in which the lens 10 shoots, in accordance with changes over time in the celestial body direction, which is the direction from the lens 10 to the celestial body, based on celestial body information, position information, time information, and roll angle information. In the tracking command process S33, the processor 31 determines the changes over time in the celestial body direction, calculates the drive amount and drive direction of the vibration-proof lens 131 for changing the shooting direction in accordance with the changes over time, and transmits the calculation result as a command signal to the processor 11 of the lens 10 via the communication interfaces 36 and 12. When the processor 11 receives the command signal from the processor 31, the processor 11 starts the tracking process S11.

[0045] The tracking command process S33 will be described in more detail with reference to Fig. 3. Fig. 3 is a flowchart showing the flow of each process included in the tracking command process S33 shown in Fig. 2. As shown in Fig. 3, the tracking command process S33 includes a celestial body direction determination process S331, a drive amount calculation process S332, and a command transmission process S333.

[0046] The celestial body direction determination process S331 is a process in which the processor 31 determines changes in the celestial body direction over time. The celestial body direction determination process S331 will be described with reference to Fig. 4. Fig. 3 shows a diagram of the celestial sphere for explaining the celestial body direction determination process S331. In Fig. 4, the illustrated components represent the following: PS: The celestial body being photographed PP: Shooting position VP:Zenith VE: Vernal equinox CE: Celestial Equator N: True North S: Due South H: Hour angle δ: Declination α: Right ascension θ: Azimuth angle in the direction of the celestial body φ: Elevation angle toward the celestial body Ψ: Roll angle around the shooting direction

[0047] In this embodiment, in the celestial body direction determination process S331, the processor 31 searches a celestial body database that indicates the equatorial coordinates (declination δ and right ascension α) of any celestial body for the celestial body represented by the celestial body information acquired in the acquisition process S32, and acquires the equatorial coordinates of the celestial body PS. Next, the processor 31 converts the acquired equatorial coordinates into direction cosine coordinates (L, M, N) expressed by the following equations.

[0048]

number

[0049] The processor 31 also determines the longitude of the photographing position PP based on the position information acquired in the acquisition process S32. The processor 31 determines the local sidereal time at the photographing position PP at the time of photographing based on the longitude and the time information acquired in the acquisition process S32, and determines the hour angle H based on the local sidereal time and the longitude of the photographing position PP. The processor 31 then determines the azimuth angle θ and elevation angle φ of each celestial body direction in horizontal coordinates by applying a rotation matrix A, which rotates each element of the direction cosines (L, M, N) by the amount shown in the following equation (1), to the direction cosines (L, M, N). In equation (1), X represents the latitude of the photographing position PP. Here, because the hour angle H changes in accordance with changes in local sidereal time, the rotation matrix A is set for each time at the photographing position PP. Therefore, the azimuth angle θ and elevation angle φ output by applying the rotation matrix A to the direction cosines (L, M, N) are also determined for each time, and the processor 31 determines the changes in the azimuth angle θ and elevation angle φ over time by the above-mentioned processing.

[0050]

number

[0051] In this embodiment, the celestial body database is stored in memory 32, but the present invention is not limited to this, and the celestial body database may be stored in any readable, non-transitory recording medium, such as a server, that can communicate with the operation terminal 30. When the celestial body direction determination process S331 is completed, the processor 31 starts the drive amount calculation process S332.

[0052] In the present invention, the method for determining the time-dependent changes in the azimuth angle θ and elevation angle φ of the celestial body direction is not limited to the specific processing described above, and any processing that uses celestial body information, position information, and time information can be adopted.

[0053] In the drive amount calculation process S332, the processor 31 calculates the drive amount and drive direction of the vibration-proof lens 131. The drive amount calculation process S332 will be described with reference to FIG. 5. FIG. 5 is a graph for explaining the drive amount calculation process S332 shown in FIG. 3. The graph shown in FIG. 5 is a graph showing an example of changes over time in the azimuth angle θ and elevation angle φ of the celestial body direction determined in the celestial body direction determination process S331. In the drive amount calculation process S332, the processor 31 calculates changes Δθ and Δφ in the celestial body direction from the current time T0 represented by the time information acquired in the acquisition process S32 to time T1 after an arbitrary time ΔT has elapsed. Next, the processor 31 converts the calculated changes Δθ and Δφ into a change in the shooting direction using the roll angle Ψ represented by the roll angle information acquired in the acquisition process S32. Next, the processor 31 calculates the drive amount and drive direction of the vibration-proof lens 131 to achieve the obtained change in the shooting direction. In this embodiment, the correspondence relationship between changes in the shooting direction and the drive amount and drive direction of the anti-vibration lens 131 is stored in the memory 32 of the operation terminal 30. The processor 31 calculates the drive amount and drive direction by incorporating changes in the shooting direction into this correspondence relationship. The drive amount and drive direction are calculated as a function with elapsed time ΔT as an explanatory variable and the drive amount and drive direction as objective variables. This function is calculated from elapsed time ΔT=0 (i.e., the current time) to ΔT at which at least one of the drive amount and drive direction reaches the limit of the movable range of the anti-vibration lens 131. When the drive amount calculation process S332 is completed, the processor 31 starts the command transmission process S333.

[0054] The command transmission process S333 is a process in which the processor 31 transmits the drive amount and drive direction of the vibration-proof lens 131 calculated in the drive amount calculation process S332 as a command signal to the processor 11 of the lens 10. When the processor 11 receives the command signal, the processor 11 starts the tracking process S11.

[0055] (Lens 10 control process S10) The control process S10 of the lens 10 will be described with reference to Fig. 2. The control process S10 is a process for causing the lens 10 to change the shooting direction in accordance with changes in the direction of the celestial body over time, in accordance with a command signal transmitted based on celestial body information, position information, and time information. The control process S10 is mainly executed by the processor 11 of the lens 10. As shown in Fig. 2, the control process S10 includes a tracking process S11.

[0056] In the tracking process S11, the processor 11 changes the shooting direction in accordance with the change in the direction of the celestial body over time. When the processor 11 receives the command signal transmitted from the processor 31 in the command transmission process S333, the processor 11 operates the lens actuator 14 over time to drive the vibration-proof lens 131 in accordance with the drive amount and drive direction for each elapsed time ΔT.

[0057] (User operation) As can be understood from the above description, the lens 10 tracks the celestial object by changing the shooting direction in accordance with the change in the direction of the celestial object over time while the processor 11 is executing the tracking process S11. The lens 10 and the camera 20 are installed so that the shooting direction coincides with the direction of the celestial body at the start of the tracking process S11. In the input reception process S31, predetermined information is input to the touch display 33, At any timing during the tracking process S11, the release switch 22 of the camera 20 is turned on to start shooting. At any timing during the tracking process S11, the release switch 22 of the camera 20 is turned off to end the photographing. By performing this operation, an image in which the image of a celestial body is formed at a fixed point on the image sensor 23 can be captured.

[0058] (Effects of the first embodiment) In this embodiment, the celestial object tracking system 100 includes a processor 31 and a lens 10. The processor 31 executes an acquisition process S32 for acquiring celestial object information, position information, and time information, and a tracking command process S33 for changing the shooting direction of the lens 10 in accordance with changes in the celestial object direction over time based on the celestial object information, position information, and time information. With this configuration, when the lens actuator 14 is operated to drive the vibration-proof lens 131, the method for driving the vibration-proof lens 131 has already been determined, eliminating the need to simultaneously perform measurement by the geomagnetic sensor and drive by the actuator. This enables highly accurate tracking of celestial objects. Furthermore, with this configuration, the user's preparatory operations for tracking celestial objects are primarily to point the lens 10 toward the celestial object and input predetermined information into the touch display 33. This eliminates the need for time-consuming preparatory operations, such as the preliminary photography disclosed in JP 2012-5112 A, and simplifies the preparatory operations. Furthermore, with this configuration, image processing based on the celestial image formed on the imaging element 23 disclosed in Patent Publication No. 2020-173343 is not required, so the computing power of the camera 20 can be low or nonexistent, and the required equipment is inexpensive.

[0059] In this embodiment, the processor 31 further acquires roll angle information indicating the roll angle Ψ of the lens 10 around the shooting direction in an acquisition process S32, and then, in a tracking command process S33, changes the shooting direction by causing the lens 10 to drive the vibration-proof lens 131 of the shooting optical system 13 included in the lens 10 based on the roll angle information. With this configuration, the shooting direction can be changed by driving a component included inside the shooting device (lens 10). Therefore, it is possible to track a celestial body without using equipment for changing the orientation of the shooting device itself, such as a movable stage.

[0060] In this embodiment, a configuration is adopted in which the celestial body tracking system 100 includes an operation terminal 30 that accepts input of roll angle information. With this configuration, sensors for measuring the roll angle, such as multiple acceleration sensors, are not required, and the required equipment is inexpensive.

[0061] In this embodiment, the celestial body tracking system 100 includes an operation terminal 30 that accepts input of celestial body information by a user. This configuration eliminates the need for equipment to detect the celestial body that is the subject, and allows the celestial body tracking system 100 to use an inexpensive imaging device.

[0062] Also included in the scope of this embodiment is a celestial body tracking method for photographing a celestial body while tracking it, characterized in that it includes the steps of acquiring celestial body information, position information, and time information (acquisition process S32), and causing the lens 10 to change the photographing direction, which is the direction in which the lens 10 photographs, in accordance with changes in the celestial body direction over time, based on the celestial body information, position information, and time information (tracking command process S33). Such a celestial body tracking method can provide the same effects as those of the celestial body tracking system 100.

[0063] Also within the scope of this embodiment is a program for controlling a celestial body tracking system 100 for photographing celestial bodies while tracking them, the program including a processor 31 and a lens 10, the program causing the processor 31 to execute an acquisition process S32 for acquiring celestial body information, position information, and time information, and a tracking command process S33 for causing the lens 10 to change the photographing direction in accordance with changes in the celestial body direction over time based on the celestial body information, position information, and time information (control processing program P30 of the operation terminal 30). Such a program can achieve the same effects as those of the celestial body tracking system 100. Furthermore, a recording medium (including a non-transitory computer-readable recording medium) for storing such a program also falls within the scope of this embodiment.

[0064] (Modification of the first embodiment) In this embodiment, a configuration is adopted in which the shooting direction is changed by driving the vibration-proof lens 131 of the lens 10, but the present invention is not limited to this configuration. Any means for changing the shooting direction can be used in the present invention. As one example, the shooting direction may be changed by driving any component built into the lens 10 or the camera 20 and located on the optical axis OA, such as the image sensor 23 built into the camera 20. As another example, the shooting direction may be changed by changing the orientation of the entire lens 10 or the entire camera 20. An example of a means for changing the orientation of the entire lens 10 or the entire camera 20 is an electric pan head that connects the camera 20 to a tripod.

[0065] In the present invention, the operation terminal 30 is not limited to a smartphone. The operation terminal 30 may be any device capable of receiving input of celestial body information or roll angle information from a user, acquiring position information or time information, or any combination thereof. Examples of the operation terminal 30 include wearable devices such as smart watches, VR goggles, or smart glasses; and car navigation systems.

[0066] In the present invention, the position information and time information are based on the position and time measured by the GNSS sensor 34 and the clock 35, respectively, but the present invention is not limited to this configuration. The position information and time information may be based on any means capable of measuring the shooting position and shooting time. Furthermore, if the shooting position and shooting time are determined in advance, the position information and time information may be input by the user via any input device.

[0067] In this embodiment, the processor 31 acquires the current time and date from the clock 35 as the time information. However, the present invention is not limited to this configuration. In the acquisition process S32, the processor 31 may acquire, as the time information, information indicating the time at which the user desires to start tracking, instead of the current time. In this case, the operation terminal 30 may execute the tracking command process S33 so that the processor 11 of the lens 10 starts the tracking process S11 from the time at which the user desires to start tracking.

[0068] [Embodiment 2] A second embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the first embodiment, and the description thereof will not be repeated.

[0069] (Celestial Tracking System 200) The configuration of a celestial object tracking system 200 according to a second embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a block diagram showing the configuration of the celestial object tracking system 200 according to the second embodiment of the present invention. The celestial object tracking system 200 is a system for photographing a celestial object while tracking it in order to preferably obtain a point image of the celestial object.

[0070] 1, celestial body tracking system 200 includes lens 10A and camera 40. Lens 10A is attached to the mount of camera 40, and when photographing celestial bodies, lens 10A and camera 40 function together as an imaging device. Lens 10A and camera 40 are connected to each other via mount communication so that they can communicate with each other.

[0071] (Lens 10A) Lens 10A is configured to form a subject image on an imaging element 23 included in camera 40. As shown in FIG. 6, lens 10A includes a processor 11, a communication interface 12A, a photographing optical system 13, a lens actuator 14, and an optical system sensor 15. The configuration of lens 10A is the same as that of lens 10 in the first embodiment, except that communication interface 12 of lens 10 is replaced with communication interface 12A, and communication interface 12A is a mount communication interface. Description of the other configuration of lens 10A will not be repeated.

[0072] (Camera 40) The camera 40 functions as a photographing device that converts the subject image formed on the image sensor 23 into an image, and as an input device through which the user inputs various pieces of information referenced by the celestial body tracking system 200, and is configured to process the various pieces of information and control the entire celestial body tracking system 200. In this embodiment, the camera body of a digital camera is used as the camera 40. As shown in FIG. 6 , the camera 20 includes a processor 21, a release switch 22, a memory 41, a GNSS sensor 42, a clock 43, a touch display 44, a communication interface 45, a geomagnetic sensor 46, an acceleration sensor 47, the image sensor 23, and an element actuator 48.

[0073] The processor 21 is configured to control the overall operation of the camera 40. In this embodiment, a CPU is used as the processor 21. The processor 21 mainly executes a control process S40 for the camera 40 by expanding and executing a control process program P40 stored in the memory 41. The control process S40 executed by the processor 21 will be described later with reference to different drawings. The configuration of the release switch 22 is the same as the configuration of the release switch 22 in the first embodiment, and therefore the description thereof will not be repeated.

[0074] The memory 41 includes a primary memory and a secondary memory. The primary memory volatilely stores celestial body information, position information, time information, and roll angle information. The secondary memory nonvolatilely stores the control processing program P40 and image data.

[0075] The GNSS sensor 42 is a sensor for a satellite positioning system, which measures the position (latitude and longitude) of the camera 40 on the Earth and outputs the measurement results to the processor 21. The clock 43 is configured to measure the current time and date. The touch display 44 is configured to display a UI for the user to input operations and to accept inputs from the user.

[0076] The communication interface 45 is configured to control the transmission of various data from the camera 40 and the reception of various data by the camera 40. In this embodiment, a mount communication interface is used as the communication interface 45.

[0077] The geomagnetic sensor 46 is a sensor for measuring the angle between the imaging direction of the camera 40 and the meridian, i.e., the azimuth angle of the camera 40. The acceleration sensor 47 is composed of multiple acceleration sensors arranged in orthogonal directions and is a sensor for measuring the attitude angle of the camera 40 relative to the direction of gravity, i.e., the elevation angle and roll angle of the camera 40. The processor 21 can obtain the imaging direction of the camera 40 based on the azimuth angle and elevation angle measured by the geomagnetic sensor 46 and the acceleration sensor 47, respectively. In other words, in this embodiment, the combination of the geomagnetic sensor 46 and the acceleration sensor 47 functions as a sensor for measuring the imaging direction. The acceleration sensor 47 can also be called a sensor for measuring the roll angle of the camera 40 around the imaging direction.

[0078] The configuration of the image sensor 23 is the same as that of the image sensor 23 in the first embodiment, and therefore its description will not be repeated. The element actuator 48 is an actuator that drives the image sensor 23. The element actuator 48 has an element drive circuit and drives the image sensor 23 based on a control signal from the processor 21. In this embodiment, the attitude angle of the lens 10A and the camera 40 relative to the ground is constant during image capture. Therefore, the directional relationship between the lens 10A and the camera 40 and the celestial body being the subject changes over time due to the rotation of the Earth, etc. However, by driving the vibration-proof lens 131 and the image sensor 23 in accordance with the change in the directional relationship over time, it is possible to adjust the position at which the celestial body image is formed on the image sensor 23 to be constant. In this embodiment, the direction in which the lens 10A and the camera 40 capture images, that is, the direction from the capture position toward the light source of the light rays that form an image at a fixed point on the image sensor 23, is referred to as the capture direction. In this embodiment, the lens 10A and the camera 40 can change the shooting direction within a range of approximately ±0.5° for both the azimuth angle and the elevation angle by driving the vibration-proof lens 131 and the image sensor 23.

[0079] (Control process S200 of celestial body tracking system 200) The control process S200 of the celestial body tracking system 200 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the flow of processes executed by each processor of the celestial body tracking system 200 shown in Fig. 6. The control process S200 is a process for changing the shooting direction, which is the direction in which the lens 10A and the camera 40 shoot images, in accordance with changes over time in the celestial body direction, which is the direction from the shooting position toward the celestial body, based on celestial body information that indicates the celestial body that is the subject, position information that indicates the shooting position, and time information that indicates the shooting time.

[0080] As shown in Fig. 7, the control process S200 includes a control process S40 for the camera 40 and a control process S50 for the lens 10A. The control process S40 includes a detail determination process S41, an input reception process S42, an acquisition process S43, a tracking command process S44, and a photographing process S45. The control process S50 includes a focal length transmission process S51 and a tracking process S52. The control process S200 includes The processor 11 of the lens 10A executes a focal length transmission process S51, The processor 21 of the camera 40 executes a detailed determination process S41, an input reception process S42, an acquisition process S43, a tracking command process S44, and a photographing process S45 in conjunction with the focal length transmission process S51, The processor 11 of the lens 10A executes the tracking process S52 in conjunction with the tracking command process S44. Each process included in the control process S200 of the celestial body tracking system 200 will be explained below.

[0081] The focal length transmission process S51 is a process in which the processor 11 of the lens 10A transmits information indicating the focal length of the lens 10A to the processor 21 of the camera 40. The processor 11 calculates the focal length of the lens 10A based on the current positions of the optical element group included in the photographing optical system 13 output from the optical system sensor 15, and transmits information indicating the calculation result to the processor 21 of the camera 40 via the communication interface 12A and the communication interface 45. When the processor 21 of the camera 40 receives the information indicating the focal length, it starts the detail determination process S41.

[0082] In the detail determination process S41, the processor 21 of the camera 40 determines the level of detail of the input of celestial object information to be received by the touch display 44 in the subsequent input reception process S42, based on the focal length of the lens 10A. Detail represents the degree of uniqueness of the celestial object information among the celestial object information representing the celestial object that is the subject of the celestial object information. The processor 21 determines that the longer the focal length received from the processor 11 of the lens 10A, the higher the level of detail of the celestial object information (the more detailed the celestial object information is). The processor 21 adjusts the UI of the touch display 44 so that the user inputs celestial object information with a level of detail equal to or greater than the determined level of detail. In this embodiment, the processor 21 determines the level of detail of the celestial object information to be one of three levels: "low," "medium," or "high." If the determined level of detail is "low", the UI of the touch display 44 requests the user to input celestial object information representing either the time and direction when the star is visible (level of detail "low"), the constellation including the star (level of detail "medium"), or a single star (level of detail "high"). If the determined level of detail is "medium", the UI of the touch display 44 requests the user to input celestial object information representing either the constellation including the star (level of detail "medium") or a single star (level of detail "high"). If the determined level of detail is "high", the UI of the touch display 44 requests the user to input celestial object information representing a single star (level of detail "high"). When the processor 21 adjusts the UI of the touch display 44, the processor 21 starts an input reception process S42.

[0083] The input reception process S42 is a process in which the touch display 44 receives input of various information from the user and transmits it to the processor 21. In this embodiment, the touch display 44 receives input of celestial body information and time information indicating the desired time to start shooting from the user. Here, with regard to the celestial body information, the user inputs celestial body information with a predetermined level of detail in accordance with the UI adjusted in the detail determination process S41. When the processor 21 receives the various information received by the touch display 44, the processor 21 starts the acquisition process S43.

[0084] In the acquisition process S43, the processor 21 acquires various pieces of information to be referenced in the tracking command process S44 from the various components of the celestial body tracking system 200. When the processor 21 acquires the various pieces of information, the processor 21 starts the tracking command process S44. In this embodiment, the processor 21: As the celestial body information, the celestial body information received from the touch display 33 in the input reception process S42 is acquired, The latitude and longitude of the camera 40 measured by the GNSS sensor 42 are acquired from the GNSS sensor 42 as position information; As the time information, the time information received from the touch display 33 in the input reception process S42 is acquired, As the shooting direction information, information representing the azimuth angle and elevation angle of the camera 40 measured by the geomagnetic sensor 46 and the acceleration sensor 47 is acquired from the geomagnetic sensor 46 and the acceleration sensor 47, respectively; As roll angle information, information indicating the roll angle of the camera 40 around the shooting direction measured by the acceleration sensor 47 is acquired from the acceleration sensor 47.

[0085] The tracking command process S44 is a process in which the processor 21 changes the shooting direction, which is the direction in which the lens 10A and the camera 40 shoot images, in accordance with changes over time in the celestial body direction, which is the direction from the lens 10A and the camera 40 to the celestial body, based on celestial body information, position information, time information, shooting direction information, and roll angle information. In the tracking command process S44, the processor 21 determines the change over time in the celestial body direction, calculates the drive amount and drive direction of the vibration-proof lens 131 and the image sensor 23 so that the shooting direction changes in accordance with the change over time, and transmits the calculation result as a command signal to the processor 11 of the lens 10 via the communication interfaces 45 and 12A. When the processor 11 receives the command signal from the processor 21, the processor 11 starts the tracking process S52.

[0086] The tracking command process S44 will be described in more detail with reference to Fig. 8. Fig. 8 is a flowchart showing the flow of each process included in the tracking command process S44 shown in Fig. 7. As shown in Fig. 8, the tracking command process S44 includes a celestial body direction determination process S441, a direction deviation notification process S442, a drive amount calculation process S443, and a command transmission process S444.

[0087] Since the celestial body direction determination process S441 is the same as the celestial body direction determination process S331 in embodiment 1, the same component numbers are given in parentheses and their descriptions will not be repeated. When the celestial body direction determination process S441 (S331) is completed, the processor 21 starts the direction deviation notification process S442.

[0088] The direction deviation notification process S442 is a process in which the processor 21 notifies the user of the deviation between the celestial body direction and the shooting direction based on the celestial body direction determined in the celestial body direction determination process S441 (S331) and the shooting direction information acquired in the acquisition process S43. The processor 21 calculates the deviation between the celestial body direction at the desired shooting start time indicated by the time information and the current shooting direction, and displays the calculation result on the touch display 44. This display allows the user to refer to the calculation result and adjust the shooting direction to reduce the deviation by moving the camera 40 and lens 10A. After displaying the deviation on the touch display 44, the processor 21 executes the drive amount calculation process S443.

[0089] In the drive amount calculation process S443, the processor 21 calculates the drive amount and drive direction of the vibration-proof lens 131 and the image sensor 23. The drive amount calculation process S443 is similar to the drive amount calculation process S332 in the first embodiment except that it takes into account the drive of the image sensor 23 in addition to the vibration-proof lens 131, and therefore description thereof will not be repeated. When the drive amount calculation process S443 is completed, the processor 21 starts the command transmission process S444.

[0090] The command transmission process S444 is a process in which the processor 21 transmits the drive amount and drive direction of the vibration-proof lens 131 calculated in the drive amount calculation process S443 as a command signal to the processor 11 of the lens 10. When the processor 11 receives the command signal, the processor 11 starts the tracking process S52. Furthermore, when the processor 21 transmits the command signal, the processor 21 starts the photographing process S45.

[0091] In the tracking process S52, the processor 11 operates the lens actuator 14 to drive the vibration-proof lens 131 in accordance with the command signal transmitted from the processor 31 in the command transmission process S444. In the photographing process S45, the processor 21 operates the element actuator 48 to drive the image sensor 23 from the desired time of photographing acquired as the time information, in accordance with the drive amount and drive direction of the image sensor 23 calculated in the drive amount calculation process S443, and causes the image sensor 23 to photoelectrically convert the formed subject image and generate a photoelectric conversion signal. The tracking process S52 by the processor 11 and the photographing process S45 by the processor 21 are executed synchronously. That is, the combination of driving the vibration-proof lens 131 in the lens 10 and driving the image sensor 23 in the camera 40 changes the photographing direction in accordance with changes in the direction of the celestial body over time.

[0092] (Effects of the second embodiment) In this embodiment, a configuration is adopted in which the camera 40 is equipped with an acceleration sensor 47 that measures the roll angle of the camera 40. With this configuration, by referring to the roll angle of the camera 40 measured by the acceleration sensor 47, the celestial body tracking system 200 can track celestial bodies with higher accuracy than in the case of embodiment 1 in which roll angle information is input by a user. Furthermore, the multiple acceleration sensors arranged in orthogonal directions that function as the acceleration sensor 47 in this embodiment are often inexpensive.

[0093] In this embodiment, the camera 40 includes a geomagnetic sensor 46 and an acceleration sensor 47 for measuring the shooting direction. The processor 21 of the camera 40 further acquires shooting direction information indicating the shooting direction in an acquisition process S43. In a tracking command process S44, the processor 21 executes a direction deviation notification process S442 that notifies the user of a deviation between the celestial body direction and the shooting direction based on the celestial body direction and the shooting direction. This configuration allows the user to adjust the shooting direction by referring to the deviation notified to reduce the deviation. This reduces the deviation between the shooting direction and the celestial body direction at the start of shooting, and the tracking command process S44 changes the shooting direction in accordance with changes in the celestial body direction over time during shooting, enabling celestial body tracking with higher accuracy.

[0094] In this embodiment, the processor 21 of the camera 40 further executes a detail determination process S41 that determines the level of detail of the celestial object information input to be received by the touch display 44 based on the focal length of the lens 10A. Generally, in photography, the shorter the focal length, the wider the angle of view, and therefore the proportion of the celestial object's movement (corresponding to the amount of change in the celestial object's direction over time) in the angle of view becomes smaller. Therefore, even if the imaging direction has poor tracking ability to changes in the celestial object's direction over time due to low detail of the celestial object information, a point image of the celestial object may be obtained if the focal length is short. This embodiment determines the level of detail of the celestial object information input based on the focal length, so it is possible to require the user to input information with a level of detail high enough to obtain a point image of the celestial object, yet low enough to allow easy input.

[0095] 〔summary〕 As can be understood from the above description, the present invention includes the following aspects.

[0096] Aspect 1: A celestial body tracking system for photographing a celestial body while tracking it, the celestial body tracking system including at least one processor and an imaging device, wherein the at least one processor executes an acquisition process for acquiring celestial body information representing the celestial body that is the subject of the image, location information representing the imaging location, and time information representing the imaging time, and a tracking command process for issuing to the imaging device, based on the celestial body information, location information, and time information, a change in the imaging direction, which is the direction in which the imaging device takes images, in line with changes over time in the celestial body direction, which is the direction from the imaging location toward the celestial body.

[0097] Aspect 2: The celestial body tracking system of aspect 1, characterized in that, in the acquisition process, the at least one processor further acquires roll angle information representing the roll angle of the imaging device around the imaging direction, and in the tracking command process, changes the imaging direction by causing the imaging device to drive at least one of the image sensor and the imaging optical system equipped in the imaging device based on the roll angle information.

[0098] Aspect 3: The celestial body tracking system of Aspect 2, further comprising at least one input device that accepts input of the roll angle information by a user.

[0099] Aspect 4: The celestial body tracking system of Aspect 2, wherein the image capturing device is equipped with a sensor that measures the roll angle of the image capturing device.

[0100] Aspect 5: A celestial body tracking system according to any one of Aspects 1 to 4, characterized in that the imaging device is equipped with a sensor that measures the imaging direction, and the at least one processor further acquires imaging direction information representing the imaging direction in the acquisition process, and in the tracking command process, executes a direction deviation notification process that notifies a user of the deviation between the celestial body direction and the imaging direction based on the celestial body direction and the imaging direction.

[0101] Aspect 6: A celestial body tracking system according to any one of Aspects 1 to 5, characterized in that it includes at least one input device that accepts input of the celestial body information by a user.

[0102] Aspect 7: The celestial body tracking system of aspect 6, characterized in that the at least one processor further performs a detail determination process to determine the detail of the input of celestial body information accepted by the at least one input device based on the focal length of the imaging device.

[0103] Aspect 8: A celestial body tracking method for photographing a celestial body while tracking it, characterized in that the method includes: acquiring celestial body information that represents the celestial body that is the subject, location information that represents the shooting location, and time information that represents the shooting time; and, based on the celestial body information, the location information, and the time information, causing an imaging device to change the shooting direction, which is the direction in which the imaging device takes images, in line with changes over time in the celestial body direction, which is the direction from the shooting location toward the celestial body.

[0104] Aspect 9: A celestial body tracking system for photographing a celestial body while tracking it, the celestial body tracking system including at least one processor and an imaging device, characterized in that the program controls the celestial body tracking system, causing the at least one processor to execute an acquisition process for acquiring celestial body information representing the celestial body that is the subject of the image, location information representing the imaging location, and time information representing the imaging time, and a tracking command process for causing the imaging device to change the imaging direction, which is the direction in which the imaging device takes images, in accordance with changes over time in the celestial body direction, which is the direction from the imaging location toward the celestial body.

[0105] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0106] 10, 10A lenses 11, 21, 31 processors 13. Shooting optical system 14 Lens Actuator 15 Optical Sensor 20, 40 cameras 23 Image sensor 24, 32, 41 memory 30 Operation terminal 33, 44 Touch display 34, 42 GNSS sensor 35, 43 Clock 46 Geomagnetic Sensor 47 Accelerometer 48-element actuator 100, 200 celestial tracking system 131 Anti-vibration lens

Claims

1. A celestial object tracking system for photographing a celestial object while tracking it, the celestial object tracking system includes at least one processor and an image capture device; The at least one processor an acquisition process for acquiring celestial body information representing the celestial body that is the subject, location information representing the shooting location, and time information representing the shooting time; and executing a tracking command process for causing the photographing device to change the photographing direction, which is the direction in which the photographing device photographs, in accordance with a time-dependent change in the celestial body direction, which is the direction from the photographing position toward the celestial body, based on the celestial body information, the position information, and the time information. A celestial body tracking system.

2. The at least one processor In the acquisition process, roll angle information representing a roll angle of the image capturing device around the image capturing direction is further acquired; In the tracking command process, the photographing direction is changed by driving at least one of an image sensor and a photographing optical system provided in the photographing device based on the roll angle information.

2. The celestial body tracking system according to claim 1 .

3. and at least one input device that accepts input of the roll angle information by a user.

3. The celestial body tracking system according to claim 2.

4. The imaging device includes a sensor for measuring a roll angle of the imaging device.

3. The celestial body tracking system according to claim 2.

5. the imaging device includes a sensor for measuring the imaging direction; The at least one processor In the acquisition process, imaging direction information indicating the imaging direction is further acquired, In the tracking command process, a direction deviation notification process is executed to notify a user of a deviation between the celestial body direction and the imaging direction based on the celestial body direction and the imaging direction.

5. The celestial body tracking system according to claim 1, wherein:

6. and at least one input device that accepts input of the celestial body information by a user.

5. The celestial body tracking system according to claim 1, wherein:

7. the at least one processor further executes a detail determination process for determining a detail of the input of the celestial body information to be received by the at least one input device based on a focal length of the image capture device.

7. A celestial body tracking system according to claim 6.

8. A celestial object tracking method for photographing a celestial object while tracking it, comprising: Acquiring celestial body information that indicates the celestial body being the subject, location information that indicates the shooting location, and time information that indicates the shooting time; and changing the photographing direction, which is the direction in which the photographing device photographs, in accordance with a time-dependent change in the celestial body direction, which is the direction from the photographing position toward the celestial body, based on the celestial body information, the position information, and the time information. A celestial body tracking method comprising:

9. A celestial object tracking system for photographing a celestial object while tracking the celestial object, the celestial object tracking system including at least one processor and an imaging device, the at least one processor; an acquisition process for acquiring celestial body information representing the celestial body that is the subject, location information representing the shooting location, and time information representing the shooting time; and causing the photographing device to execute a tracking command process for changing an image capturing direction, which is a direction in which the photographing device captures images, in accordance with a time-dependent change in a celestial body direction, which is a direction from the photographing position toward the celestial body, based on the celestial body information, the position information, and the time information. A program characterized by:

Images