Radar system, radar information sharing method, and program

Abstract

[PROBLEM] To provide a radar system capable of sharing required object data and suppressing the communication data amount. [SOLUTION] This radar system comprises: a radar sensor that generates echo data by receiving reflected waves of electromagnetic waves emitted in the environs of a ship; a generation unit that, on the basis of the echo data, generates object data which includes the position and the speed of objects existing in the environs of the ship; a selection unit that selects, from among the objects, display objects and non-display objects; and an output unit that makes the priority for outputting the object data of the display objects higher than that for the object data of the non-display objects, and that outputs the object data.

Description

Radar system, radar information sharing method, and program

[0001] The present invention relates to a radar system, a radar information sharing method, and a program.

[0002] Patent Document 1 discloses a radar signal recording and reproducing device having a recording system that records radar video obtained from a radar device onto a recording medium, and a reproducing system that reproduces the radar video from the recording medium.

[0003] Japanese Patent Application Publication No. 10-253749

[0004] The target data generated by the radar system installed on the ship is output to a display that displays radar images, etc., or to other ships or land-based devices via maritime communications. However, sharing all target data uniformly can be wasteful.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its main object is to provide a radar system, a radar information sharing method, and a program that are capable of sharing required target data.

[0006] In order to solve the above problem, a radar system according to one aspect of the present invention includes a radar sensor that receives reflected waves of radio waves emitted around a ship and generates echo data, a generator that generates target data including positions and velocities of targets present around the ship based on the echo data, a selector that selects targets to be displayed and targets to be not displayed from the targets, and an output unit that outputs the target data by giving the output priority of the target data of the targets to be displayed higher than that of the targets to be not displayed. This makes it possible to preferentially share the target data of the targets to be displayed.

[0007] In the above aspect, the navigation system may further include an acquisition unit that acquires vessel data including a speed of the vessel, and a calculation unit that calculates risk data representing a risk of collision between the vessel and the target based on the vessel data and the target data, and the output unit may output the sequentially calculated risk data by giving a higher output priority to the risk data related to the display target than to the risk data related to the non-display target. This makes it possible to preferentially share the risk data related to the display target.

[0008] In the above aspect, the output unit may change the output priority of the target data of the display target, the target data of the non-display target, the risk data related to the display target, and the risk data related to the non-display target according to the type of output destination. This makes it possible to share the target data and the risk data with an output priority appropriate for the output destination.

[0009] In the above aspect, the output unit may switch the output priority of the target data of the non-display target and the output priority of the risk data related to the display target according to the type of output destination. This makes it possible to share the target data and the risk data with an output priority appropriate for the output destination.

[0010] In the above aspect, when the output destination is outside the vessel, the output unit may assign output priorities to the target data of the display target, the target data of the non-display target, the risk data related to the display target, and the risk data related to the non-display target in descending order of output priority. This makes it possible to prioritize the target data and share the target data and risk data.

[0011] In the above aspect, when the output destination is a display unit provided on the ship, the output unit may assign output priorities to the target data of the display target, the risk data related to the display target, the target data of the non-display target, and the risk data related to the non-display target in descending order of output priority. This makes it possible to prioritize the display data and share the target data and risk data.

[0012] In the above aspect, the display unit may display a speed symbol indicating the speed of the display target and a collision risk area related to the display target, thereby making it possible to display the speed symbol and the collision risk area using the display data that is output with priority.

[0013] In the above aspect, the output unit may output data with a low output priority less frequently than data with a high output priority, thereby making it possible to change the output frequency according to the output priority.

[0014] In the above aspect, the output unit may set a compression level for data with a low output priority higher than a compression level for data with a high output priority, thereby making it possible to change the compression level according to the output priority.

[0015] In the above aspect, the selection unit may select, as the display target, a target having a collision risk equal to or greater than a predetermined value based on the risk data. This makes it possible to select, as the display target, a target having a collision risk.

[0016] In the above aspect, the present invention may further include a specifying unit that specifies a display target range to be displayed on the image, and the selecting unit may select targets included in the display target range as the display targets. This makes it possible to select targets included in the display target range as the display targets.

[0017] In the above aspect, the selection unit may select a target object designated by a user as the target object for display. This makes it possible to select the target object designated by the user as the target object for display.

[0018] In addition, a radar information sharing method according to another aspect of the present invention includes generating echo data using a radar sensor that receives reflected waves of radio waves emitted around a ship, generating target data including positions and velocities of targets present around the ship based on the echo data, selecting targets to be displayed and targets to be not displayed from the targets, and outputting the target data by giving the output priority of the target data of the targets to be displayed higher than that of the targets to be not displayed. This makes it possible to preferentially share the target data of the targets to be displayed.

[0019] According to another aspect of the present invention, a program causes a computer to execute the following steps: generate echo data using a radar sensor that receives reflected waves of radio waves emitted around a ship; generate target data including positions and velocities of targets present around the ship based on the echo data; select targets to be displayed and targets to be not displayed from the targets; and output the target data by giving the target data of the targets to be displayed a higher output priority than the target data of the targets to be not displayed. This makes it possible to preferentially share the target data of the targets to be displayed.

[0020] 1 is a diagram illustrating an example of the configuration of a radar system. FIG. 1 is a diagram illustrating an example of the configuration of a control unit. FIG. 1 is a diagram illustrating an example of a target management database. FIG. 1 is a diagram illustrating an example of an risk management database. FIG. 1 is a diagram illustrating an example of a display management database. FIG. 2 is a diagram illustrating an example of echo data. FIG. 2 is a diagram illustrating an example of calculation of a collision risk area. FIG. 3 is a diagram illustrating an example of calculation of CPA. FIG. 3 is a diagram illustrating an example of selection of display targets. FIG. 4 is a diagram illustrating an example of display of a radar image. FIG. 5 is a diagram illustrating an example of display of symbols. FIG. 6 is a diagram illustrating an example of display of symbols. FIG. 7 is a diagram illustrating an example of display of symbols. FIG. 8 is a diagram illustrating an example of display of a chart image. FIG. 9 is a diagram illustrating an example of the procedure of a radar display method. FIG. 10 is a diagram illustrating an example of output priority. FIG. 11 is a diagram illustrating an example of the procedure of a radar information sharing method. FIG. 12 is a diagram illustrating an example of the configuration of a display control unit. FIG. 13 is a diagram illustrating an example of a virtual three-dimensional space. FIG. 14 is a diagram illustrating an example of a three-dimensional image. FIG. 15 is a diagram illustrating an example of the setting of a virtual camera. FIG. 16 is a diagram illustrating an example of the field of view of a virtual camera. FIG. 17 is a diagram illustrating an example of the setting of a virtual camera. FIG. 18 is a diagram illustrating an example of the field of view of a virtual camera.

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements similar to those described above with reference to the previous drawings will be designated by the same reference numerals, and detailed descriptions thereof may be omitted as appropriate.

[0022] [System Overview] Fig. 1 is a block diagram showing an example configuration of a radar system 100. In the following description, a ship on which the radar system 100 is installed is referred to as the "own ship," and other ships are referred to as "other ships." The radar system 100 includes a radar sensor 1, a display unit 2, an operation unit 3, and a control unit 10.

[0023] The radar sensor 1 emits radio waves around the ship, receives reflected waves, and generates echo data based on the received signals. The radar sensor 1 includes an antenna, a transmitting / receiving unit, and a signal processing unit.

[0024] The signal received from the antenna passes through a frequency conversion / amplification circuit and a detection circuit included in the transmitting / receiving unit, undergoes signal processing in the signal processing unit, and is then supplied as a digital signal to the control unit 10. In the signal processing, the echo data is processed to suppress unnecessary echoes caused by waves and the like, and to make it easier to identify echoes from targets such as other ships.

[0025] The display unit 2 is, for example, a liquid crystal display device or an organic EL display device. The display unit 2 displays a radar image RMG (see FIG. 10) generated by the control unit 10. The display unit 2 may also display a chart image CMG (see FIG. 12) or a three-dimensional image DMG (see FIG. 19), etc.

[0026] The operation unit 3 is, for example, a pointing device such as a trackball. Alternatively, the operation unit 3 may be a touch panel provided on the screen of the display unit 2. A user who operates the operation unit 3 inputs a designated position on the screen of the display unit 2.

[0027] The control unit 10 includes a computer including a CPU, RAM, ROM, non-volatile memory, an input / output interface, etc. The CPU of the control unit 10 executes information processing in accordance with a program loaded from the ROM or non-volatile memory to the RAM.

[0028] The program may be supplied via an information storage medium such as an optical disk or a memory card, or may be supplied via a communication network such as the Internet or a LAN.

[0029] The radar system 100 also includes an AIS 4, a camera 5, a GNSS receiver 6, a gyrocompass 7, an ECDIS 8, and a wireless communication unit 9. These devices are capable of network communication with a control unit 10 via a communication network such as a LAN.

[0030] The AIS (Automatic Identification System) 4 receives AIS data from other ships around the ship or from land-based control. Instead of AIS, a VHF Data Exchange System (VDES) may also be used. The AIS data includes the identification code, name, position, course, speed, type, length, and destination of other ships.

[0031] The camera 5 is a digital camera that captures images of the outside world from the ship and generates image data. The camera 5 is installed, for example, on the bridge of the ship, facing the bow. The camera 5 is, for example, a so-called PTZ camera that has pan / tilt and optical zoom functions.

[0032] The camera 5 may include an image recognition unit that estimates the position and type of a target object, such as another ship, included in a captured image using an object detection model. The image recognition unit is not limited to the camera 5 and may be implemented in another device, such as the control unit 10.

[0033] The GNSS receiver 6 detects the ship's position based on radio waves received from the Global Navigation Satellite System (GNSS). The gyrocompass 7 detects the ship's heading. A GPS compass may be used instead of a gyrocompass.

[0034] An ECDIS (Electronic Chart Display and Information System) 8 acquires the ship's position from the GNSS receiver 6 and displays the ship's position on an electronic chart. The ECDIS 8 also displays the ship's planned route on the electronic chart. A GNSS plotter may be used instead of an ECDIS.

[0035] The wireless communication unit 9 includes wireless equipment for realizing satellite communication, and wireless equipment for realizing wireless communication using, for example, ultra-high frequency waves, very high frequency waves, short frequency waves, medium frequency waves, or medium waves.

[0036] In this embodiment, the display image generated by the control unit 10 is displayed on the display unit 2, but this is not limiting and the image may be displayed on the display unit of another device such as the ECDIS 8, for example.

[0037] In addition, in this embodiment, the radar system 100 is mounted on the ship and used to monitor targets such as other ships around the ship, but this is not limited to this, and the radar system may also be installed in a control center on land, for example, and used to monitor ships navigating in a controlled sea area.

[0038] [Configuration of Control Unit] Fig. 2 is a block diagram showing an example of the configuration of the control unit 10 of the radar system 100. Figs. 3 to 5 are diagrams showing examples of the contents of a DB (database) constructed in the memory of the control unit 10.

[0039] As shown in Figure 2, the control unit 10 includes a ship data acquisition unit 11, a target data generation unit 12, an input acceptance unit 13, a planned route acquisition unit 14, a risk data calculation unit 15, a target selection unit 16, a data output unit 17, a display control unit 18, and a display target range identification unit 19.

[0040] These functional units are realized by the CPU of the control unit 10 executing information processing in accordance with a program. Note that some of the functional units may be realized by other devices such as the ECDIS 8.

[0041] The vessel data acquisition unit 11 acquires vessel data including the position and speed of the vessel. The speed is a vector quantity expressed by the vessel speed and course, and the vessel speed is a scalar quantity.

[0042] Specifically, the ship data acquisition unit 11 sequentially acquires the ship's position detected by the GNSS receiver 6 and calculates the ship's speed from the change in the ship's position over time. Alternatively, the ship's speed may be acquired from a speedometer (not shown), and the ship's course may be acquired from the gyrocompass 7.

[0043] The target data generator 12 generates target data including the positions and velocities of targets present around the ship based on the echo data successively generated by the radar sensor 1. The target data is so-called TT data (Target Tracking Data).

[0044] In addition to the target data (TT data) based on the echo data, the target data generation unit 12 may further use AIS data received by the AIS 4 or identification data identified from an image captured by the camera 5 as target data.

[0045] The target data generating unit 12 registers the generated target data in a target management DB (see FIG. 3) for managing targets.

[0046] 3, the target management DB includes fields such as "target ID," "position," "ship speed," "course," and "elapsed time." The "target ID" is an identifier assigned to a target.

[0047] "Position" indicates the position of the target. The position of the target is a relative position expressed by the direction and distance to the ship. The position of the target may be converted to an absolute position using the position of the ship detected by the GNSS receiver 6.

[0048] "Ship speed" indicates the speed of the target. "Course" indicates the course of the target. The speed and course of the target are estimated from the change in the target's position over time. "Elapsed time" indicates the time elapsed since the target was detected.

[0049] 6 is a diagram showing an example of echo data EC generated by the radar sensor 1. The echo data EC is generated for each rotation of the antenna. Targets such as other ships are identified from the echo data EC from the past few scans.

[0050] The figure shows echo data EC in a PPI (Plan Position Indicator) format, which shows the relationship between distance and direction radially from the ship's position, but this is not limited to this and may also be in an RHI (Range Height Indicator) format, with direction on the horizontal axis and distance on the vertical axis.

[0051] The echo data EC includes an echo point ET corresponding to the target. The center CT of the echo data EC represents the position of the ship. The line segment HD extending upward from the center CT represents the direction of the ship's bow.

[0052] 2, the input receiving unit 13 receives a user operation input from the operation unit 3. The user operation input is, for example, an operation input for indicating an echo point ET in a radar image RMG (see FIG. 10), or an operation input for changing the display target range of a chart image CMG (see FIG. 12) or a three-dimensional image DMG (see FIG. 19).

[0053] The planned route acquisition unit 14 acquires the planned route of the ship from the ECDIS 8. The planned route is, for example, a planned route to a destination based on a navigation plan. However, the planned route acquisition unit 14 may also calculate an avoidance route to avoid a collision when the collision risk calculated by the risk data calculation unit 15 is equal to or greater than a predetermined value.

[0054] The risk data calculation unit 15 calculates risk data representing the risk of collision between the ship and the target based on the ship data and the target data. The risk data calculation unit 15 registers the calculated risk data in the risk management DB (see FIG. 4).

[0055] Specifically, the risk data calculation unit 15 calculates a collision risk area where the risk of collision between the ship and a target is greater than or equal to a predetermined value as risk data. The collision risk area is, for example, an OZT (Obstacle Zone by Target). However, other areas such as a PAD (Predict Area of ​​Danger) or a DAC (Dangerous Area of ​​Collision) may also be used.

[0056] The risk data calculation unit 15 may also calculate the DCPA (Distance to Closest Point of Approach) and TCPA (Time to Closest Point of Approach) of the CPA collision warning as risk data. Without being limited to this, for example, BCR (Bow Crossing Range) and BCT (Bow Crossing Time) may also be used. The risk data calculation unit 15 may also simply calculate the current distance from the ship to the target as risk data.

[0057] Furthermore, the risk data calculation unit 15 may calculate risk data when the ship is navigating the planned route acquired by the planned route acquisition unit 14. For example, the risk data calculation unit 15 may calculate the risk of collision between the ship and a target for each of multiple legs that make up the planned route, and integrate these to generate risk data.

[0058] 7 is a diagram showing an example of calculating a collision risk area. The risk data calculation unit 15 calculates, as the collision risk area, sections L1 and L2 of the predicted route R of the target OP where the risk of collision between the ship SH and the target OP is greater than or equal to a predetermined value, when it is assumed that the ship SH changes course in an arbitrary direction and crosses the predicted route R of the target OP.

[0059] The risk data calculation unit 15 calculates the separation distance between the predicted position of the ship SH and the predicted position of the target OP at each time point, and calculates the risk of collision based on the separation distance and the ship size. The risk data calculation unit 15 extracts the position closest to the predicted position of the target OP at the same time point from the circle representing the predicted position of the ship SH at the same time, and calculates the separation distance.

[0060] For example, when a warning area P set around the own ship SH overlaps with a point representing the predicted position of the target OP, the risk data calculation unit 15 determines that the risk of collision is equal to or greater than a threshold and identifies risk sections L1 and L2. Hereinafter, the traveling direction of the target OP will also be referred to as the forward direction, and the opposite direction will also be referred to as the backward direction.

[0061] Of the two risk zones L1, L2, for the first risk zone L1 located on the aft side, the aft end L1R of the first risk zone L1 is a position where the forward end of the warning area P of the ship SH abuts on the point representing the predicted position of the target OP. The forward end L1F of the first risk zone L1 is a position where the aft end of the warning area P of the ship SH abuts on the point representing the predicted position of the target OP.

[0062] On the other hand, for the second risk zone L2 located on the forward side of the two risk zones L1, L2, the aft end L2R of the second risk zone L2 is a position where the aft end of the warning area P of the ship SH abuts on the point representing the predicted position of the target OP. The front end L2F of the second risk zone L2 is a position where the front end of the warning area P of the ship SH abuts on the point representing the predicted position of the target OP.

[0063] The range between the first risk zone L1 and the second risk zone L2 is the range in which the ship SH crosses ahead of the target OP. On the other hand, the range behind the first risk zone L1 and the range ahead of the second risk zone L2 are the ranges in which the ship SH crosses behind the target OP. When the ship SH crosses ahead of the target OP, more care is required than when the ship SH crosses behind the target OP.

[0064] Without being limited to this, the risk data calculation unit 15 may determine that the risk of collision is above a threshold, for example, when a warning area P set in the area of ​​the own ship SH or around the own ship SH overlaps with a warning area set in the area of ​​the target OP or around the target OP.

[0065] In addition, the risk data calculation unit 15 may determine that the risk of collision is above a threshold, for example, when the distance between a point representing the predicted position of the ship SH and a point representing the predicted position of the target OP is below a threshold.

[0066] 8 is a diagram showing an example of calculation of DCPA and TCPA. DCPA is the closest distance between the target OP and the own ship SH, and TCPA is the time it takes for the target OP to come closest to the own ship SH.

[0067] As shown in Fig. 4, the risk management DB includes fields such as "target ID," "collision risk," "OZT," and "CPA." "OZT" represents the position of the collision risk area. Specifically, it represents the range from the start point to the end point of the collision risk area. "CPA" represents the values ​​of DCPA and TCPA.

[0068] The "collision risk" indicates whether the risk of collision with the ship is equal to or greater than a predetermined value. For example, if a collision risk area exists on the ship's heading line or on the planned route, or if both the DCPA and TCPA are below thresholds, the risk of collision with the ship is determined to be equal to or greater than a predetermined value.

[0069] 2, the target selection unit 16 selects display targets and non-display targets from among the targets detected by the radar sensor 1. The target selection unit 16 registers the selection results in a display management DB (see FIG. 5).

[0070] Specifically, the target selection unit 16 selects, as display targets, targets with a predetermined or higher collision risk based on the risk data calculated by the risk data calculation unit 15. For example, targets with a collision risk area on the ship's bow line or planned route, or targets with both DCPA and TCPA below thresholds, are selected as display targets.

[0071] The target selection unit 16 may also select targets for which a collision risk area has been calculated as display targets. For example, all targets for which a collision risk area has been calculated within a predetermined distance from the ship SH are selected as display targets.

[0072] Furthermore, the target selection unit 16 may select, as a display target, a target for which a collision risk area OZ is calculated within a predetermined range FS determined according to the traveling direction of the ship, as shown in Fig. 9. The predetermined range FS is, for example, a fan-shaped range centered in the bow direction HD and located at a distance from the ship SH that is equal to or less than a predetermined distance.

[0073] The predetermined range FS may be changed depending on the maneuvering performance of the ship SH. For example, in order to set the predetermined range FS according to the maneuvering performance of the ship SH, the predetermined range FS may be narrowed as the ship SH is larger or its speed is higher, and widened as the ship SH is smaller or its speed is lower.

[0074] Furthermore, the target selection unit 16 may select targets with a predetermined or higher risk of collision as display targets, and then further select targets within a predetermined distance from the selected targets as display targets, thereby gradually expanding the display targets.

[0075] The target selection unit 16 selects, as display targets, targets that are currently or will be included in the display target range identified by the display target range identification unit 19. The display target range identification unit 19 identifies, from within the surroundings of the ship, a display target range that corresponds to the image generated by the display control unit 18. The identification of the display target range will be described in detail below.

[0076] The target selection unit 16 selects a target indicated by the user as a display target based on the user's operational input received by the input receiving unit 13. For example, when there is an operational input to indicate an echo point ET in the radar image RMG (see FIG. 10) displayed on the display unit 2, the target corresponding to the echo point ET is selected as a display target.

[0077] As shown in FIG. 5, the display management DB includes fields such as "target ID," "display," "collision risk," "display target range," and "user instruction."

[0078] "Collision risk" indicates whether an object has been selected as a display target based on risk data. "Display target range" indicates whether an object has been selected as a display target based on the display target range. "User instruction" indicates whether an object has been selected as a display target by user instruction.

[0079] "Display" indicates whether or not the object is a display target. That is, a white circle in "Display" indicates that the object has been selected as a display target in either "Collision Risk," "Display Target Range," or "User Instruction."

[0080] 2, the data output unit 17 outputs the target data generated by the target data generation unit 12 and selected by the target selection unit 16 as either display or non-display data, and the risk data calculated by the risk data calculation unit 15, to the wireless communication unit 9 and the display unit 2. The output of the target data and risk data will be described in detail later.

[0081] The display control unit 18 generates a display image such as a radar image RMG (see Figure 10) or a chart image CMG (see Figure 12) based on the target data and risk data output by the data output unit 17, and displays it on the display unit 2.

[0082] 10 is a diagram showing a display example of a radar image RMG. The radar image RMG is an image based on the echo data EC (see FIG. 6) and includes echo points ET corresponding to targets. A trajectory TR representing the past movement of the targets is added to the echo points ET.

[0083] Here, the echo points ET are classified into echo points ETd of display targets selected by the target selection unit 16 and echo points ETn of non-display targets.

[0084] The display control unit 18 displays a speed symbol VT representing the speed of the display target at a position in the radar image RMG that corresponds to the actual position of the display target. That is, the display control unit 18 adds the speed symbol VT to the echo point ETd of the display target, but does not add the speed symbol VT to the echo point ETn of the non-display target.

[0085] The display control unit 18 also displays a collision risk area OZ related to the display target at a position within the radar image RMG that corresponds to the actual position of the collision risk area identified by the risk data calculation unit 15. The collision risk area OZ is displayed ahead of the speed symbol VT of the echo point ETd of the display target.

[0086] As shown in FIG. 11A, the speed symbol VT is arranged with the echo point ETd as the starting point, with a length corresponding to the ship speed of the display target and a direction corresponding to the course.

[0087] 11B, in addition to the velocity symbol VT, target symbols SB and BR indicating the position of the display target may be further displayed. For example, the circular target symbol SB may be displayed superimposed on the echo point ETd, or the parenthesized target symbol BR may be displayed surrounding the echo point ETd.

[0088] Also, as shown in FIG. 11C, the echo point ETd and the trajectory TR may not be displayed, and only the velocity symbol VT and the target symbol SB may be displayed.

[0089] 12 is a diagram showing a display example of a chart image CMG. The chart image CMG is an image based on an electronic chart. The chart image CMG may be a north-up display in which the north direction corresponds to the top of the image, or a head-up display in which the bow direction of the ship corresponds to the top of the image.

[0090] The chart image CMG includes a ship symbol BB indicating the ship's position, a planned route RT for the ship, and a waypoint WP. The chart image CMG also includes a target symbol SB, a speed symbol VT, and a collision risk area OZ similar to those described above.

[0091] The display control unit 18 displays the target symbol SB and the speed symbol VT of the display target at a position within the chart image CMG that corresponds to the actual position of the display target. The display control unit 18 also displays the collision risk area OZ related to the display target at a position within the chart image CMG that corresponds to the actual position of the collision risk area.

[0092] The display control unit 18 may further display a target symbol AB and a speed symbol VT based on other target data such as AIS data.

[0093] The display control unit 18 changes the display range of the chart image CMG in response to a user operation input received by the input receiving unit 13. The change in the display range may be, for example, a translation, enlargement, or reduction of the display range. In addition, in the case of a head-up display, the display range may change depending on the direction of travel of the ship.

[0094] The display target range of the chart image CMG is specified by the display target range specifying unit 19 and notified to the target selection unit 16. The display target range refers to the real range corresponding to the range within the nautical chart displayed on the chart image CMG. When the display target range is changed, the target selection unit 16 selects targets included in the changed display target range as display targets.

[0095] 13 is a diagram showing an example of the procedure of a radar display method implemented in the radar system 100. The control unit 10 of the radar system 100 periodically executes the information processing shown in the diagram in accordance with a program.

[0096] First, the control unit 10 acquires ship data including the position and speed of the ship (S11, processing as the ship data acquisition unit 11).

[0097] Next, the control unit 10 acquires the echo data EC (see FIG. 6) generated by the radar sensor 1 (S12), and generates target data including the position and velocity of the target based on the echo data EC for several scans (S13, processing as the target data generation unit 12).

[0098] Next, the control unit 10 selects one piece of target data from the generated plurality of pieces of target data (S14), and calculates risk data based on the ship data and the target data (S15, risk data calculation unit 15).

[0099] Next, if the risk of collision between the ship and the target is greater than or equal to a predetermined value based on the calculated risk data (S16: YES), the control unit 10 selects the target as a display target (S20, processing as the target selection unit 16).

[0100] In addition, if a target is included in the display range of a display image such as a radar image RMG (see Figure 10) displayed on the display unit 2 (S17: YES), the control unit 10 selects the target as a display target (S20, processing as the target selection unit 16).

[0101] In addition, when a target is indicated by the user on a display image such as a radar image RMG (see Figure 10) displayed on the display unit 2 (S18: YES), the control unit 10 selects the target as a display target (S20, processing as the target selection unit 16).

[0102] On the other hand, if the risk of collision between the ship and the target is less than a predetermined value (S16: NO), if the target is not included in the display range (S17: NO), or if the target is not specified by the user (S18: NO), the control unit 10 selects the target as a target to be hidden (S19, processing as the target selection unit 16).

[0103] The control unit 10 repeats the above-described processing of S14 to S20 until all targets have been selected (S21).

[0104] Thereafter, the control unit 10 displays the target symbol SB of the display target, the speed symbol VT, the collision risk area OZ, etc. on a display image such as a radar image RMG (see FIG. 10) (S22, processing as the display control unit 18). With the above, the series of processes for symbol display is completed.

[0105] [Data Output] The following describes a specific example of data output by the data output unit 17. As shown in Figure 2, the data output unit 17 outputs target data and risk data that are generated sequentially to the wireless communication unit 9 and the display unit 2.

[0106] The wireless communication unit 9 transmits the target data and risk data to a device outside the ship, for example, on land or on another ship. As described above, the display unit 2 displays a display image such as a radar image RMG (see FIG. 10 ) based on the target data and risk data.

[0107] The data output unit 17 outputs the target data by setting the output priority of the target data for the display target higher than that of the target data for the non-display target. Also, the data output unit 17 outputs the risk data related to the display target higher than that of the risk data related to the non-display target.

[0108] For example, the output priority corresponds to the output frequency. The higher the output priority, the higher the data output frequency, and the lower the output priority, the lower the data output frequency. The data output unit 17 outputs data with a low output priority less frequently than data with a high output priority.

[0109] The output frequency is the frequency at which target data or risk data is included in the periodically transmitted data set, and may be, for example, a time-based frequency such as once every few seconds, minutes, or tens of minutes, or a frequency based on the number of times, such as once every several or several tens of times.

[0110] The output priority may correspond to the compression level of the data. The higher the output priority, the lower the compression level of the data, and the lower the output priority, the higher the compression level of the data. The data output unit 17 sets the compression level of data with a low output priority higher than that of data with a high output priority.

[0111] The degree of data compression is also referred to as the degree of data reduction or the degree of data thinning. For example, in the target data, items other than the position and speed may be reduced, and in the risk data, items in which the distance or time until collision or approach is greater than a predetermined value may be deleted.

[0112] The data output unit 17 changes the output priority of the target data of the display target, the target data of the non-display target, the risk data related to the display target, and the risk data related to the non-display target according to the type of output destination. That is, the output priority of the target data of the non-display target and the output priority of the risk data related to the display target are switched according to the type of output destination.

[0113] 14, when the output destination is outside the ship, the data output unit 17 assigns the following output priorities in descending order: (1) target data for display targets, (2) target data for non-display targets, (3) risk data related to display targets, and (4) risk data related to non-display targets. This allows target data to be shared with devices on land or other ships with priority.

[0114] 15, when the output destination is the display unit 2, the data output unit 17 assigns the following output priorities in descending order of priority: (1) target data of the display target, (2) risk data related to the display target, (3) target data of the non-display target, and (4) risk data related to the non-display target. This gives priority to the target data and risk data used for display.

[0115] 16 is a diagram showing an example of the procedure of a radar information sharing method implemented in the radar system 100. The control unit 10 of the radar system 100 functions as a data output unit 17 by periodically executing the information processing shown in the diagram in accordance with a program.

[0116] First, the control unit 10 determines whether the output destination is outside the ship or the display unit 2 (S31).

[0117] If the output destination is outside the ship, the control unit 10 outputs the target data and risk data sequentially (S33) in the order of highest output priority: (1) target data for display targets, (2) target data for non-display targets, (3) risk data related to display targets, and (4) risk data related to non-display targets (S32, see Figure 14).

[0118] On the other hand, when the output destination is the display unit 2, the control unit 10 outputs the target data and risk data sequentially (S35) in the order of highest output priority: (1) target data of the display target, (2) risk data related to the display target, (3) target data of the non-display target, and (4) risk data related to the non-display target (S34, see Figure 15).

[0119] This completes the series of processes for data output.

[0120] [Three-dimensional display] An example of three-dimensional display by the display control unit 18 will be described below. Fig. 17 is a diagram showing an example of the configuration of the display control unit 18. The display control unit 18 includes a symbol placement unit 21, a virtual camera setting unit 22, and an image generation unit 23.

[0121] Fig. 18 is a diagram showing an example of a virtual three-dimensional space VS. The virtual three-dimensional space VS has a coordinate system corresponding to the real space. Fig. 19 is a diagram showing an example of a three-dimensional image DMG generated by the display control unit 18.

[0122] The symbol placement unit 21 places the ship symbol BB at a position on the virtual water surface VF of the virtual three-dimensional space VS that corresponds to the actual position of the ship, based on the ship data acquired by the ship data acquisition unit 11 (see Figure 2). The symbol placement unit 21 also places the planned route RT and waypoints WP of the ship.

[0123] In addition, the symbol placement unit 21 places a target symbol SB representing the display target at a position on the virtual water surface VF of the virtual three-dimensional space VS that corresponds to the actual position of the display target, based on the target data of the display target generated by the target data generation unit 12 (see Figure 2) and output by the data output unit 17.

[0124] In this example, the ship symbol BB and the target symbol SB are configured as three-dimensional objects resembling ship hulls. However, the ship symbol BB and the target symbol SB may be two-dimensional objects such as circles.

[0125] In addition, the symbol placement unit 21 places the collision risk area OZ at a position on the virtual water surface VF of the virtual three-dimensional space VS that corresponds to the actual position of the collision risk area based on the risk data related to the display target calculated by the risk data calculation unit 15 (see Figure 2) and output by the data output unit 17.

[0126] The symbol placement unit 21 may distinguish target symbols SB of display targets that have a predetermined or higher risk of collision with the ship, such as target symbols SB having a collision risk area OZ, from other target symbols SB by, for example, differentiating the color, shape, or texture.

[0127] The virtual camera setting unit 22 sets a virtual camera VC in the virtual three-dimensional space VS. The virtual camera setting unit 22 sets the virtual camera VC at a predetermined relative position with respect to the ship symbol BB. The virtual camera setting unit 22 also moves the virtual camera VC in accordance with the movement of the ship symbol BB.

[0128] The display target range specifying unit 19 specifies a display target range corresponding to the field of view ES of the virtual camera VC. Once the display target range is specified, the target selection unit 16 selects targets included in the display target range as display targets, and the symbol placement unit 21 places target symbols SB representing the display targets in the virtual three-dimensional space VS.

[0129] Furthermore, even if a target is not currently included in the display target range, if the target includes a collision risk area, it corresponds to a target that will be included in the display target range in the future, so the target selection unit 16 may also select such a target as a target for display.

[0130] The image generator 23 generates a three-dimensional image DMG by drawing a scene within the field of view ES of the virtual camera VC in the virtual three-dimensional space VS. As shown in Fig. 19, the three-dimensional image DMG includes an own ship symbol BB, a target symbol SB, a collision risk area OZ, and the like that are present within the field of view ES of the virtual camera VC.

[0131] The three-dimensional image DMG includes a button B1 for switching the virtual camera VC to bird's-eye view mode, a button B2 for switching to top view mode, and a button B3 for switching to bridge view mode.

[0132] The three-dimensional image DMG also includes a button B4 for changing the viewpoint position of the virtual camera VC to reset it, a button B5 for moving the viewpoint position forward, and a button B6 for moving the viewpoint position backward.

[0133] The three-dimensional image DMG also includes a button B7 for increasing the magnification of the virtual camera VC, a button B8 for decreasing the magnification, and a button B9 for switching between north-up display and head-up display.

[0134] The virtual camera setting unit 22 switches the virtual camera VC to bird's-eye view mode, top view mode, or bridge view mode in response to a user's operation input using buttons B1 to B3. The display target range specifying unit 19 updates the display target range in response to the switching of the virtual camera VC mode.

[0135] 20A and 20B are a side view and a plan view showing an example in which the virtual camera VC is set to a bird's-eye view mode, in which the virtual camera VC faces the direction of travel of the ship symbol BB and looks down diagonally on the ship symbol BB.

[0136] 21A and 21B are a side view and a plan view showing an example in which the virtual camera VC is set to a top view mode, in which the virtual camera VC is set to look directly down on the own ship symbol BB.

[0137] 22A and 22B are a side view and a plan view showing an example in which the virtual camera VC is set to a bridge view mode, in which the virtual camera VC is set to view the virtual water surface VF from a height corresponding to the wheelhouse of the own ship symbol BB.

[0138] The real range corresponding to the range SR including the portion of the field of view ES of the virtual camera VC above the virtual water surface VF and its surroundings is specified as the display target range. By making not only the field of view ES of the virtual camera VC but also its surroundings correspond to the display target range, it is possible to position the target symbol SB in advance at the destination of the field of view ES of the virtual camera VC.

[0139] The virtual camera setting unit 22 moves the virtual camera VC in accordance with the movement of the ship symbol BB. Specifically, the virtual camera setting unit 22 makes the virtual camera VC follow the ship symbol BB so that the relative position and attitude with respect to the ship symbol BB are maintained. The display target range specification unit 19 updates the display target range in accordance with the movement of the virtual camera VC.

[0140] The virtual camera setting unit 22 may change the position, orientation, viewing angle, magnification, etc. of the virtual camera VC in response to a user's operation input via buttons B1 to B6 or the touch panel (see FIGS. 23A and 23B ). The display target range specifying unit 19 updates the display target range in response to changes in the position, etc. of the virtual camera VC.

[0141] 24 is a diagram showing an example of the procedure of a radar display method implemented in the radar system 100. The control unit 10 of the radar system 100 periodically executes the information processing shown in the diagram in accordance with a program.

[0142] First, the control unit 10 places the own ship symbol BB at a position on the virtual water surface VF in the virtual three-dimensional space VS that corresponds to the real position of the own ship (S41, processing as the symbol placement unit 21).

[0143] Next, the control unit 10 sets a virtual camera VC in the virtual three-dimensional space VS (S42, processing as the virtual camera setting unit 22).

[0144] Next, the control unit 10 specifies a display target range corresponding to the field of view ES of the virtual camera VC (S43, processing as the display target range specifying unit 19).

[0145] Next, the control unit 10 selects, from among the targets present around the ship, targets within the display target range as display targets (S44, processing as the target selection unit 16).

[0146] Next, the control unit 10 places the target symbol SB of the display target at a position on the virtual water surface VF of the virtual three-dimensional space VS that corresponds to the real position of the display target (S45, processing as the symbol placement unit 21).

[0147] Next, the control unit 10 renders the scene within the visual field ES of the virtual camera VC in the virtual three-dimensional space VS to generate a three-dimensional image DMG (S46, processing as the image generation unit 23).

[0148] The control unit 10 repeatedly executes the series of processes described above while updating the positions of the ship symbol BB, the target symbol SB, and the virtual camera VC.

[0149] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made by those skilled in the art.

[0150] In the above embodiment, the display unit 2 is connected to the control unit 10, and the display unit 2 displays the image generated by the display control unit 18. However, this is not limited to this, and a device including the display unit 2 and the display control unit 18 may be provided separately from the control unit 10, and may receive target data and risk data from the control unit 10 via a communication network.

[0151] In the above embodiment, the radar system 100 is mounted on a ship, but this is not limiting and the radar system 100 may be installed on land. When multiple ships are present in the area from which the radar sensor 1 emits radio waves, risk data can be calculated by treating one ship as a "ship" and the other ships as "targets."

[0152] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made by those skilled in the art.

[0153] Representative embodiments of the present invention will be listed below.

[0154] (1) A radar system comprising: a radar sensor that receives reflected waves of radio waves emitted around a ship and generates echo data; a generation unit that generates target data including the positions and velocities of targets present around the ship based on the echo data; a selection unit that selects targets to be displayed and targets to be not displayed from the targets; and an output unit that gives the output priority of the target data of the targets to be displayed higher than the target data of the targets to be not displayed and outputs the target data.

[0155] (2) The radar system described in (1) further comprises: an acquisition unit that acquires ship data including the speed of the ship; and a calculation unit that calculates risk data representing the risk of collision between the ship and the target based on the ship data and the target data, wherein the output unit gives a higher output priority to the risk data related to the target for display than to the risk data related to the target for non-display, and outputs the risk data that is calculated sequentially.

[0156] (3) The radar system according to (2), wherein the output unit changes output priorities of the target data of the target for display, the target data of the target for non-display, the risk data related to the target for display, and the risk data related to the target for non-display according to a type of output destination.

[0157] (4) The radar system according to (2) or (3), wherein the output unit switches an output priority of the target data of the non-display target and an output priority of the risk data related to the display target depending on a type of output destination.

[0158] (5) A radar system according to any one of (2) to (4), wherein when the output destination is outside the ship, the output unit assigns output priorities in the order of highest to lowest: target data of the target for display, target data of the target for non-display, risk data related to the target for display, and risk data related to the target for non-display.

[0159] (6) A radar system described in any of (2) to (5), wherein when the output destination is a display unit provided on the ship, the output unit assigns output priorities in the order of highest to lowest: target data of the target for display, risk data related to the target for display, target data of the target for non-display, and risk data related to the target for non-display.

[0160] (7) The radar system according to (6), wherein the display unit displays a speed symbol representing a speed of the display target and a collision risk area related to the display target.

[0161] (8) The radar system according to (6) or (7), wherein the output unit outputs data having a low output priority less frequently than data having a high output priority.

[0162] (9) The radar system according to any one of (6) to (8), wherein the output unit increases the compression level of data having a low output priority compared to data having a high output priority.

[0163] (10) The radar system according to any one of (2) to (9), wherein the selection unit selects, as the display target, a target having a collision risk equal to or greater than a predetermined risk based on the risk data.

[0164] (11) The radar system according to any one of (1) to (10), further comprising a specifying unit that specifies a display target range to be displayed on the image, wherein the selecting unit selects targets included in the display target range as the targets for display.

[0165] (12) The radar system according to any one of (1) to (11), wherein the selection unit selects a target designated by a user as the target for display.

[0166] (13) A radar information sharing method, comprising: generating echo data using a radar sensor that receives reflected waves of radio waves emitted around a ship; generating target data including positions and velocities of targets present around the ship based on the echo data; selecting targets to be displayed and targets to be not displayed from the targets; and outputting the target data by giving the output priority of the target data of the targets to be displayed higher than that of the target data of the targets to be not displayed.

[0167] (14) A program for causing a computer to execute the following steps: generating echo data using a radar sensor that receives reflected waves of radio waves emitted around the ship; generating target data including the positions and velocities of targets present around the ship based on the echo data; selecting targets for display and targets for non-display from among the targets; and outputting the target data by giving the output priority of the target data for the targets for display higher than that of the target data for the targets for non-display. term

[0168] Not necessarily all objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, one skilled in the art will appreciate that a particular embodiment may be configured to operate to achieve or optimize one or more advantages as taught herein without necessarily achieving other objects or advantages as taught or suggested herein.

[0169] All processes described herein may be embodied and fully automated by software code modules executed by a computing system including one or more computers or processors. The code modules may be stored on any type of non-transitory computer-readable medium or other computer storage device. Some or all of the methods may be embodied in dedicated computer hardware.

[0170] Many other variations beyond those described herein will be apparent from this disclosure. For example, depending on the embodiment, certain operations, events, or functions of any of the algorithms described herein may be performed in a different sequence, added, merged, or omitted entirely (e.g., not all described acts or events are necessary to execute an algorithm). Furthermore, in certain embodiments, operations or events may be performed in parallel rather than sequentially, e.g., via multithreading, interrupt processing, or multiple processors or processor cores, or on other parallel architectures. Furthermore, different tasks or processes may be performed by different machines and / or computing systems that may function together.

[0171] The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein may be implemented or executed by a machine such as a processor. The processor may be a microprocessor, but alternatively, the processor may be a controller, microcontroller, or state machine, or a combination thereof. The processor may include electrical circuitry configured to process computer-executable instructions. In another embodiment, the processor includes an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable device that performs logical operations without processing computer-executable instructions. A processor may also be implemented as a combination of computing devices, such as a combination of a digital signal processor (DSP) and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. Although described herein primarily with reference to digital technology, a processor may also include primarily analog elements. For example, some or all of the signal processing algorithms described herein may be implemented by analog circuitry or mixed analog and digital circuitry. The computing environment can include any type of computer system, including, but not limited to, a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or computer system based on a computational engine within an appliance.

[0172] Unless otherwise specified, conditional language such as "can," "could," "would," or "potential" is understood within the context in which it is generally used to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language does not generally imply that features, elements, and / or steps are required in any manner in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included in or performed in any particular embodiment.

[0173] Disjunctive language such as "at least one of X, Y, Z," unless specifically stated otherwise, is understood in its general context to indicate that an item, term, etc. can be either X, Y, Z, or any combination thereof (e.g., X, Y, Z). Thus, such disjunctive language does not generally imply that a particular embodiment requires at least one of X, at least one of Y, or at least one of Z, respectively, to be present.

[0174] Any process descriptions, elements, or blocks in the flow diagrams described herein and / or illustrated in the accompanying drawings should be understood as potentially representing modules, segments, or portions of code, comprising one or more executable instructions for implementing a particular logical function or element in the process. Alternative embodiments are included within the scope of the embodiments described herein, in which elements or functions may be performed out of order, substantially simultaneously, or in reverse order from that shown or described, depending on the functionality involved, as will be understood by those skilled in the art.

[0175] Unless otherwise expressly stated, numeral terms such as "one" should generally be construed to include one or more described items. Thus, phrases such as "one device configured to" are intended to include one or more listed devices. Such one or more listed devices may also be collectively configured to perform the recited reference. For example, "a processor configured to perform the following A, B, and C" may include a first processor configured to perform A and a second processor configured to perform B and C. Additionally, even if a specific number of enumerations of the introduced embodiments are explicitly recited, those skilled in the art should construe such enumerations to typically mean at least the recited number (e.g., the mere enumeration of "two enumerations" without other modifiers typically means at least two enumerations, or two or more enumerations).

[0176] In general, it will be appreciated by those skilled in the art that the terms used herein generally intend "non-limiting" terms (e.g., the term "including" should be interpreted as "including but not limited to at least," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including, but not limited to," etc.).

[0177] For purposes of description, the term "horizontal" as used herein is defined as a plane parallel to the plane or surface of the floor of the area in which the described system is used or the plane in which the described method is performed, regardless of its orientation. The term "floor" can be interchanged with the terms "ground" or "water surface." The term "vertical / plumb" refers to a direction perpendicular / vertical to a defined horizontal line. Terms such as "upper," "lower," "below," "top," "side," "higher," "lower," "above," "over," "below," etc. are defined relative to the horizontal plane.

[0178] As used herein, the terms "attach," "connect," "mate," and other related terms, unless otherwise noted, should be interpreted to include detachable, movable, fixed, adjustable, and / or removable connections or couplings. Connections / couplings include direct connections and / or connections with intermediate structures between the two components described.

[0179] Unless otherwise expressly stated, as used herein, numbers preceded by terms such as "approximately," "about," and "substantially" are inclusive of the recited number and also refer to an amount close to the recited amount that performs the desired function or achieves the desired result. For example, "approximately," "about," and "substantially" refer to values ​​less than 10% of the recited numerical value, unless otherwise expressly stated. As used herein, features of the disclosed embodiments preceded by terms such as "approximately," "about," and "substantially" refer to features that have some variability that also perform the desired function or achieve the desired result for that feature.

[0180] Many variations and modifications may be made to the above-described embodiments, and these elements should be understood to be among other acceptable examples. All such modifications and variations are intended to be included within the scope of this disclosure and are protected by the following claims.

[0181] DESCRIPTION OF SYMBOLS 1 Radar sensor, 2 Display unit, 3 Operation unit, 4 AIS, 5 Camera, 6 GNSS receiver, 7 Gyrocompass, 8 ECDIS, 9 Wireless communication unit, 10 Control unit, 11 Ship data acquisition unit, 12 Target data generation unit, 13 Input reception unit, 14 Planned route acquisition unit, 15 Risk data calculation unit, 16 Target selection unit, 17 Data output unit, 18 Display control unit, 19 Display target range identification unit, 21 Symbol placement unit, 22 Virtual camera setting unit, 23 Image generation unit

Claims

1. A radar system comprising: a radar sensor that receives reflected waves of radio waves emitted around a ship and generates echo data; a generation unit that generates target data including positions and speeds of targets existing around the ship based on the echo data; a selection unit that selects targets to be displayed and targets to be not displayed from among the targets; and an output unit that gives an output priority to the target data of the targets to be displayed higher than the target data of the targets to be not displayed, and outputs the target data.

2. A radar system as described in claim 1, further comprising: an acquisition unit that acquires ship data including the speed of the ship; and a calculation unit that calculates risk data representing a risk of collision between the ship and the target based on the ship data and the target data, wherein the output unit gives an output priority of the risk data relating to the display target higher than that of the risk data relating to the non-display target, and outputs the risk data calculated sequentially.

3. The radar system of claim 2, wherein the output unit changes the output priority of the target data of the target for display, the target data of the target for non-display, the risk data related to the target for display, and the risk data related to the target for non-display depending on the type of output destination.

4. The radar system according to claim 2, wherein the output unit switches the output priority of the target data of the non-display target and the output priority of the risk data related to the display target depending on the type of output destination.

5. The radar system of claim 2, wherein the output unit, when the output destination is outside the ship, assigns output priorities in the order of highest to lowest: target data of the target for display, target data of the target for non-display, risk data related to the target for display, and risk data related to the target for non-display.

6. A radar system as described in claim 2, wherein when the output destination is a display unit provided on the ship, the output unit assigns output priorities in the following order from highest to lowest: target data of the target for display, risk data related to the target for display, target data of the target for non-display, and risk data related to the target for non-display.

7. The radar system according to claim 6, wherein the display unit displays a speed symbol representing a speed of the display target and a collision risk area related to the display target.

8. The radar system according to claim 6, wherein the output unit outputs data having a low output priority less frequently than data having a high output priority.

9. The radar system according to claim 6, wherein the output unit compresses data having a low output priority more highly than data having a high output priority.

10. The radar system according to claim 2, wherein the selection unit selects, as the display object, an object having a collision risk equal to or greater than a predetermined risk based on the risk data.

11. The radar system of claim 1, further comprising an identification unit that identifies a display target range to be displayed on the image, and the selection unit selects targets included in the display target range as targets for display.

12. The radar system according to claim 1, wherein the selection unit selects a target designated by a user as the target for display.

13. A radar information sharing method, comprising: generating echo data using a radar sensor that receives reflected waves of radio waves emitted around a ship; generating target data including positions and speeds of targets present around the ship based on the echo data; selecting targets to be displayed and targets to be not displayed from among the targets; and outputting the target data by giving an output priority to the target data of the targets to be displayed higher than that of the target data of the targets to be not displayed.

14. A program for causing a computer to execute the following operations: generating echo data using a radar sensor that receives reflected waves of radio waves emitted around the ship; generating target data including positions and speeds of targets present around the ship based on the echo data; selecting targets to be displayed and targets to be not displayed from among the targets; and outputting the target data by giving an output priority to the target data of the targets to be displayed higher than that of the target data of the targets to be not displayed.

Images