JP6228750B2 - GNSS status display device and GNSS status display method - Google Patents

Description

  The present invention mainly relates to a GNSS status display device that displays status related to GNSS positioning.

  Conventionally, positioning using a GNSS (Global Navigation Satellite System) such as GPS (Global Positioning System) has been widely performed in order to detect the position of a moving body such as a ship. The GPS receiver receives positioning signals from a plurality of GPS satellites, and performs positioning based on these positioning signals.

  In GNSS such as GPS, a weak signal from a satellite is received and positioning is performed. Therefore, positioning accuracy may be reduced or positioning may not be performed depending on the reception status of the signal. Unavoidable. There are various factors that lower the positioning accuracy of GNSS. For example, it is possible to point out the location of satellites at the time of positioning, problems occurring in the satellites themselves, multipath, noise, and the like.

  In this regard, Patent Document 1 points out that GPS positioning signals can be disturbed by jamming waves and affect positioning. Further, Patent Document 2 regulates satellite information affected by multipaths by using an elevation angle and azimuth mask in order to suppress the influence of multipaths, which is one of the main factors that degrade the accuracy of position information. We have proposed a configuration that achieves highly accurate positioning calculations.

  In a navigation system using GNSS, it is extremely important that high-precision positioning by GNSS is stably performed. For this reason, in a navigation apparatus or the like that displays the positioning result of GNSS, a screen (so-called integrity screen) showing the reception status of GNSS radio waves, the arrangement of satellites, and the like can be displayed. For example, when the positioning accuracy of the GNSS is lowered, the user of the navigation apparatus can obtain information as a clue to the cause by displaying various information on this integrity screen.

JP 2007-232688 A Japanese Patent No. 4413093

  However, on the conventional integrity screen, the current state of the GNSS radio wave reception status and the like can be displayed in real time, but it is difficult to investigate the cause of the failure afterwards. In particular, when an error occurs temporarily during the voyage of a ship or the like that sails for a long period of time, it may not be possible to immediately take measures such as repairing the faulty part.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a GNSS status display device that can easily display the latest data on the status of GNSS positioning and its time history without compromising real-time performance. There is to do.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

According to a first aspect of the present invention, a GNSS status display device having the following configuration is provided. That is, a display unit for displaying the status of GNSS is provided. A graph is displayed in which one axis is a time axis and the other axis is at least one of an elevation angle of the GNSS satellite, a signal reception intensity from the GNSS satellite, and a GNSS positioning error. The graph displays the latest data while scrolling in the direction of the time axis, thereby showing the transition of the data over time in real time. The display unit displays a position in the time axis direction corresponding to a timing at which an alarm relating to GNSS positioning is generated on the graph. The display unit displays detailed information of the alarm when a position in the time axis direction corresponding to the timing at which the alarm is generated is selected. The detailed information of the alarm displayed by the display unit includes at least one of an alarm occurrence date and time and a positioning result at the time of the alarm occurrence.

Thereby, both the latest data of the situation regarding the GNSS positioning and its time history can be displayed in an easy-to-understand form as a graph. Further, since the latest data is always displayed by the scrolling graph, the user can easily understand the tendency of the data in a small display area. Then, it is possible to easily show the situation regarding the GNSS positioning in relation to the time when the alarm is generated. Furthermore, it is possible to intuitively indicate the timing at which an alarm is generated on a graph and to meet the needs of users who want to know details of the alarm. In addition, by displaying the detailed information of the alarm, the user can obtain important information regarding the alarm.

  In the GNSS status display device, when the time is indicated on the graph, the display unit preferably performs a sky plot display corresponding to the time.

  As a result, the user can obtain information on the status of satellite flight at the timing when a phenomenon such as a decrease in positioning accuracy occurs, which can be used as a clue to investigate the cause afterwards.

  In the GNSS status display device, the display unit includes a graph in which one axis is a time axis, the other axis is an elevation angle of the GNSS satellite, one axis is a time axis, and the other axis is from the GNSS satellite. It is preferable to display the signal intensity of the signal or the graph indicating the GNSS positioning error in association with each other.

  Thereby, the tendency of the data of the GNSS situation can be shown in an easily understandable manner in relation to the change in the elevation angle of the GNSS satellite.

  The GNSS status display device preferably has the following configuration. That is, the GNSS status display device includes an abnormality determination unit that determines an abnormality when the reception intensity of a signal from a GNSS satellite is lower than a predetermined signal intensity even though the elevation angle of the satellite is higher than a predetermined elevation angle. The display unit displays a determination result of the abnormality determination unit.

  Thereby, the user can know and cope with an abnormality at an early stage where the GNSS radio wave cannot be satisfactorily received from a satellite having a high elevation angle.

According to the 2nd viewpoint of this invention, the GNSS condition display method of displaying the condition of GNSS as follows is provided. That is, a graph is displayed in which one axis is a time axis and the other axis is at least one of an elevation angle of a GNSS satellite, a signal reception intensity from a GNSS satellite, or a GNSS positioning error. The graph displays the latest data while scrolling in the direction of the time axis, thereby showing the transition of the data over time in real time. The position in the time axis direction corresponding to the timing at which an alarm relating to GNSS positioning occurs is displayed on the graph. When a position in the time axis direction corresponding to the timing at which the alarm is generated is selected, detailed information on the alarm is displayed. The detailed information of the alarm includes at least one of an alarm occurrence date and time and a positioning result at the time of the alarm occurrence.

Thereby, both the latest data of the situation regarding the GNSS positioning and its time history can be displayed in an easy-to-understand form as a graph. Further, since the latest data is always displayed by the scrolling graph, the user can easily understand the tendency of the data in a small display area. Then, it is possible to easily show the situation regarding the GNSS positioning in relation to the time when the alarm is generated. Furthermore, it is possible to intuitively indicate the timing at which an alarm is generated on a graph and to meet the needs of users who want to know details of the alarm. In addition, by displaying the detailed information of the alarm, the user can obtain important information regarding the alarm.

The block diagram which shows the structure of a navigation apparatus provided with the plotter apparatus which concerns on one Embodiment of this invention. The figure which shows the example of the plotter screen which a plotter apparatus displays. The figure which shows the example of the integrity screen which a plotter apparatus displays. The enlarged view which shows a mode that the elevation angle graph of a satellite is updated in real time. The figure which shows a mode that the detail of the alarm corresponding to the alarm mark of a graph was displayed. The enlarged view which shows a mode that the graph of a carrier / noise ratio is updated in real time. The figure which shows the example which displayed the graph of the elevation angle of the GPS satellite, and the graph of the carrier / noise ratio in association with each other vertically.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a functional configuration of a navigation device 1 including a plotter device 12 as a GNSS status display device of the present embodiment. The navigation device 1 is installed on a ship as a moving body, and includes a GPS antenna (GNSS antenna) 11 and a plotter device 12.

  The GPS antenna 11 is configured as a planar antenna such as a microstrip antenna, for example, and configured to receive a 1.5 GHz band radio wave transmitted from a GPS satellite. This signal is input to the plotter device 12.

  The plotter device 12 mainly includes a GPS receiver 31, an operation unit 32, a control unit 33, and a display unit 34.

  The GPS receiver 31 receives a positioning signal from the GPS antenna 11 connected to the plotter device 12 and acquires the current position of the ship.

  The operation unit 32 includes keys, buttons, and the like, and is used for inputting various settings of the plotter device 12. A ship operator who is a user of the navigation device 1 operates the operation unit 32 to select a destination to which the ship is to be directed, a relay point (intermediate destination) that passes on the way to the destination, and the like. Can be entered. Further, by operating the operation unit 32, the ship operator can switch between a plotter screen that displays the position of the ship and an integrity screen (a GPS status screen or a GNSS status screen) that indicates the status related to GPS positioning. .

  The control unit 33 includes hardware (not shown) such as a CPU, ROM, and RAM, and software such as a GNSS status display program stored in the ROM. When the integrity screen is displayed on the display unit 34, the above-described hardware and various software operate in cooperation with each other, so that the control unit 33 can control the alarm determination unit (abnormality determination unit) 41 shown in FIG. , The graph output unit 42, the alarm mark output unit 43, the alarm detail output unit 44, and the graph update unit 45.

  The alarm determination unit 41 monitors the data output from the GPS receiver 31 during positioning, and determines that it is abnormal when a predetermined condition is satisfied, and generates a GPS alarm. There are various GPS alarm conditions. For example, when the elevation angle of a satellite is higher than a predetermined elevation angle but the signal strength from the satellite is lower than the predetermined signal strength, if a jamming wave is detected, GPS positioning cannot be performed. In this case, the positioning accuracy may be reduced, but the present invention is not limited to these. When a GPS alarm occurs, the alarm determination unit 41 alerts the vessel operator by displaying a warning (not shown) on the display unit 34, as well as the GPS alarm occurrence time, positioning result, alarm occurrence reason, etc. It memorize | stores in the memory | storage part which is not shown in figure.

  The graph output unit 42 processes the data output from the GPS receiver 31 to create a graph having the horizontal axis as time and the vertical axis as the elevation angle of the GPS satellite, and displays the graph on the display unit 34 ( (See the graph display area 65 in FIG. 3). Details of this graph will be described later.

  When a GPS alarm has occurred in the time range corresponding to the entire horizontal axis (time axis) of the graph output by the graph output unit 42, the alarm mark output unit 43 superimposes an alarm mark 71 indicating that on the graph. In this state, it is displayed on the display unit 34.

  The alarm detail output unit 44 causes the display unit 34 to display the details of the GPS alarm corresponding to the alarm mark 71 when the operation unit 32 is operated such that the alarm mark 71 is selected on the display unit 34. (See the alarm details display area 66 in FIG. 5).

  The graph update unit 45 reflects the graph output by the graph output unit 42 on the display of the graph when time elapses or when the latest data is obtained (see, for example, FIG. 4). By this real-time update, it is possible to always provide the latest time history information about the elevation angle of the GPS satellite.

  The display unit 34 is a display device configured as a liquid crystal display, for example. The display unit 34 can graphically display the position of the ship on the map based on the current position information of the ship obtained from the GPS receiver 31 (plotter screen mode).

  An example of display contents of the display unit 34 in the plotter screen mode is shown in FIG. On this plotter screen, a chart stored in advance in the plotter device 12 is displayed, and on this chart, a destination mark 56 indicating the set destination and a route line 57 indicating the scheduled route to the destination are displayed. Is displayed. Then, the current position of the ship is displayed as a boat icon 51 so as to be superimposed on the chart.

  In addition to the plotter screen mode described above, the plotter device 12 can also shift to a so-called integrity screen mode by operating the operation unit 32. In the integrity screen mode, the display unit 34 displays various information (GPS status information) including the reception state of the GPS signal for equipment maintenance and the like. By looking at the integrity screen, the ship operator can obtain information useful for investigating the cause of the decrease in GPS positioning accuracy, for example, and use it for maintenance and future ship operations.

  An output example of the integrity screen is shown in FIG. The integrity screen 60 includes a longitude / latitude display area 61 on the upper left side, an error information display area 62 and a GPS time display area 63 on the upper right side, a sky plot display area 64 on the lower left side, and a graph display area 65 on the lower right side. And an alarm detail display area 66.

  In the longitude / latitude display area 61, longitude and latitude indicating the current GPS positioning result are displayed numerically. In the error information display area 62, information on GPS positioning errors is displayed. Specifically, in this embodiment, the value of HDOP, which is the horizontal component of the degree of positional accuracy degradation (PDOP) obtained by indexing the geometrical arrangement of the satellites, is displayed in the error information display area 62. This HDOP value indicates that the positioning error is likely to increase if it is small, and the positioning error is likely to decrease if it is large. Accordingly, the ship operator can grasp the tendency of the GPS positioning error to some extent by confirming the display of the error information display area 62.

  In the sky plot display area 64, a sky plot diagram showing the current flight status of GPS satellites is displayed. In this sky plot diagram, the position of each satellite in the sky above the GPS antenna 11 is displayed as a graphic with a pseudo noise number (PRN number) identifying the satellite. As a result, the ship operator can intuitively understand how many satellites are flying, which satellite has a high elevation angle, and the like. In this sky plot diagram, among the satellites flying in the sky, the satellites actually used for positioning may be highlighted and displayed, for example, so that the display differs from the other satellites. Thereby, the marine vessel operator can easily grasp which position the GPS satellite is positioning based on.

  In the graph display area 65, a graph is displayed in which time is plotted on the horizontal axis, and parameters representing the situation regarding GPS positioning are plotted on the vertical axis. In the display example of FIG. 3, an elevation angle graph indicating the time history of the elevation angle of each GPS satellite is displayed. This elevation angle graph is represented by a collection of points, and a legend indicating the correspondence between the PRN number of the satellite and the point is displayed on the right side of the elevation angle graph.

  The display content of the elevation graph in the graph display area 65 is updated in real time by the processing of the graph update unit 45 described above. Specifically, as shown in the change from FIG. 4A to FIG. 4B, the scale on the horizontal axis of the graph is time so that the almost right end of the horizontal axis always corresponds to the current time. As the time elapses, the point gradually moves to the left, and accordingly, all the points of the existing data plotted in the graph move to the left side. In other words, the plot area in the graph scrolls to the left (side indicating the past) along the time axis as time passes. As a result of this scrolling, the plot of old data on the left end side is not displayed. On the other hand, when new data relating to the elevation angle of the satellite is obtained, a point representing the data is plotted at a position corresponding to the right end of the horizontal axis, as shown in FIG.

  Thus, the operator can easily understand both the latest data regarding the elevation angle of the satellite and the time history thereof in the form of a graph. Further, since the latest data is always displayed by the scrolling graph, the ship operator can easily understand the tendency of the data by looking at the data flowing on the graph display area 65.

  When a GPS alarm has occurred in the time range displayed in the elevation angle graph of the graph display area 65, an alarm mark 71 indicating the timing at which the GPS alarm has occurred is superimposed on the elevation angle graph. Is displayed. The alarm mark 71 includes a triangular mark 72 indicating a position (time) on the horizontal axis, and an instruction line 73 extending from the triangular mark in parallel with the vertical axis.

  The upper end of the triangular mark 72 and the instruction line 73 indicate the position in the time axis direction corresponding to the generation timing of the GPS alarm. Therefore, the ship operator can easily understand the elevation angle of the GPS satellite at the time when the alarm is generated by looking at the vicinity of the alarm mark 71 on the graph. The display position of the alarm mark 71 is updated so that the scale on the horizontal axis of the graph gradually moves to the left in accordance with the passage of time.

  Below the graph display area 65, an alarm details display area 66 for displaying the detailed contents of the GPS alarm is arranged. With this configuration, when the operator selects the position of the alarm mark 71 in the graph display area 65 (graph) by operating the operation unit 32, the content of the GPS alarm corresponding to the alarm mark 71 is as shown in FIG. Are displayed in the alarm details display area 66. In the example of FIG. 5, the alarm detail display area 66 displays the date and time of alarm occurrence and the latitude and longitude that are the positioning results at the time of alarm occurrence in characters. Thereby, the ship operator can obtain important information regarding the GPS alarm.

  Note that it is conceivable that the GPS alarm occurs not only once but a plurality of times in a time range corresponding to the length of the time axis of the graph. In this case, a plurality of alarm marks 71 are displayed on the graph. When each alarm mark 71 is selected, detailed information on the corresponding GPS alarm is displayed in the alarm details display area 66.

  Further, the display unit 34 can switch the parameter of the vertical axis in the graph displayed in the graph display area 65 while the horizontal axis (time axis) remains the same according to the operation of the operation unit 32. Specifically, the carrier / noise ratio (C / No) as the signal strength of each GPS satellite is displayed on the vertical axis, or a parameter indicating a positioning error (for example, the HDOP) is displayed on the vertical axis. Can do. FIG. 6 shows an example in which a graph of the carrier / noise ratio is displayed. This graph is also along the time axis as time passes, as shown in the change from FIG. 6 (a) to FIG. 6 (b). Updated in real time to scroll.

  In the case of a graph displaying the carrier / noise ratio on the vertical axis, the elevation angle of the GPS satellite may be plotted as reference information on the graph. In this case, the time history of the elevation angle of the GPS satellite and the carrier / noise ratio is represented in one graph. Thereby, the ship operator can easily understand the tendency of the data of the carrier / noise ratio in relation to the change in the elevation angle of the GPS satellite.

  Instead of plotting the carrier / noise ratio and the elevation angle of the GPS satellite in one graph as described above, the graph display area 65 includes a graph of the elevation angle of the GPS satellite and a graph of the carrier / noise ratio. They may be displayed side by side vertically. An example of this is shown in FIG. As shown in FIG. 7, the direction in which the graphs are arranged is the vertical direction (the direction perpendicular to the time axis), and the time ranges displayed on the time axes of a plurality of graphs are matched, so Can be displayed in association with each other. The two graphs are updated simultaneously in real time so as to scroll along the time axis as time passes. Also in this case, the ship operator can grasp the fluctuation tendency of the carrier / noise ratio in relation to the elevation angle of the GPS satellite.

  In the example of FIG. 7 as well, it can be switched to display a graph of another parameter (for example, HDOP which is a parameter representing a positioning error) instead of the graph of the carrier / noise ratio.

  In the present embodiment, the sky plot diagram displayed in the sky plot display area 64 of FIG. 3 is updated in real time and is configured to always indicate the current satellite flight status. However, past flight situations may be displayed in the sky plot display area 64. For example, the following control is conceivable. That is, the user operates the operation unit 32 to instruct an arbitrary position in the plot area of the graph displayed in the graph display area 65, thereby instructing at what timing the satellite flight status is to be displayed. Then, the control unit 33 controls the display unit 34 so that the time designation cursor is displayed at the instructed position. Further, the control unit 33 controls the display unit 34 so that the flight situation at the time corresponding to the position indicated by the time designation cursor in the graph is displayed in the sky plot display area 64. The form of the time designation cursor is arbitrary, but for example, it may be an elongated cursor in a direction perpendicular to the time axis as indicated by the instruction line 73 of the alarm mark 71.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  The format of the graph (FIGS. 3 to 6) displayed in the graph display area 65 can be displayed in the form of a line graph, a bar graph, or the like, regardless of the point plot. Further, the vertical axis and the horizontal axis of the graph may be exchanged so that the time is displayed on the vertical axis side. Further, not only one but also a plurality of graphs may be arranged.

  The figure of the alarm mark 71 is displayed by a combination of a triangle and a straight line, but another figure (for example, a rhombus) may be used instead of the triangle, or a broken line instead of a straight line may be used. In the alarm mark 71, either a triangle or a straight line may be omitted. When a plurality of alarm marks 71 are displayed as described above, it is preferable that the display is made different between the alarm marks 71 in order to easily distinguish the plurality of GPS alarms.

  The alarm details display area 66 may display a pop-up screen so as to overlap the front of the graph instead of being displayed below the graph display area 65, and display details of the alarm on the pop-up screen. Further, only the alarm occurrence date and time can be displayed as the alarm detailed information, or only the positioning result at the time of the alarm occurrence can be displayed.

  The layout of the graph display area 65 and the like on the integrity screen can be changed as appropriate. Further, the graph updated in real time as described above may be displayed on a screen other than the integrity screen.

  In the above-described embodiment, the embodiment using the GPS as an example of the GNSS has been described, but it is needless to say that a configuration using another GNSS may be used.

  The navigation device of the present invention is not limited to a ship and can be mounted on an arbitrary moving body such as an airplane or an automobile.

12 Plotter device (GNSS status display device)
34 Display 60 Integrity screen (GNSS status screen)
65 Graph display area 66 Alarm detail display area 71 Alarm mark

Claims (5)

In the GNSS status display device having a display unit for displaying the status of GNSS,
The display unit
A graph with one axis as a time axis and the other axis as at least one of an elevation angle of a GNSS satellite, a signal reception intensity from a GNSS satellite, or a GNSS positioning error is displayed.
The graph, by displaying the latest data while scrolling in the direction of the time axis, shows the transition of the data over time in real time,
The position in the time axis direction corresponding to the timing when an alarm relating to GNSS positioning occurs is displayed on the graph,
When a position in the time axis direction corresponding to the timing at which the alarm is generated is selected, detailed information on the alarm is displayed,
The detailed information of the alarm displayed by the display unit includes at least one of the alarm occurrence date and time and the positioning result at the time of the alarm occurrence . The GNSS status display device according to claim 1 ,
When the time is indicated on the graph, the display unit displays a sky plot corresponding to the time. The GNSS status display device according to claim 1 or 2 ,
The display unit includes a graph in which one axis is a time axis and the other axis is an elevation angle of the GNSS satellite, and one axis is a time axis, and the other axis is a signal strength of a signal from the GNSS satellite or a GNSS positioning error. A GNSS status display device that displays the graph in association with each other. The GNSS status display device according to any one of claims 1 to 3 ,
An abnormality determination unit that determines an abnormality when the reception intensity of the signal from the GNSS satellite is lower than the predetermined signal intensity even though the elevation angle of the satellite is higher than the predetermined elevation angle;
The GNSS status display device, wherein the display unit displays a determination result of the abnormality determination unit. In the GNSS status display method for displaying the GNSS status,
A graph with one axis as a time axis and the other axis as at least one of an elevation angle of a GNSS satellite, a signal reception intensity from a GNSS satellite, or a GNSS positioning error is displayed.
The graph, by displaying the latest data while scrolling in the direction of the time axis, shows the transition of the data over time in real time,
The position in the time axis direction corresponding to the timing when an alarm relating to GNSS positioning occurs is displayed on the graph,
When a position in the time axis direction corresponding to the timing at which the alarm is generated is selected, detailed information on the alarm is displayed,
The detailed information on the alarm includes at least one of the date and time of occurrence of the alarm and the positioning result at the time of occurrence of the alarm .

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