JPH07280931A - Apparatus for displaying target position - Google Patents

Abstract

PURPOSE:To enhance the display accuracy of the position of a moving body on a radar in a land-fixed station by correcting the error of GPS positioning information from the moving body by GPS positioning information or the like in the land-fixed station. CONSTITUTION:GPS positioning information 2 from a moving body and a discrimination code are received by a land-fixed station, and they are sent sequentially to an image-information processing means 8. On the other hand, in the land-fixed station, a GPS receiver 9 always receives radio waves from a satellite, and positioning information is stored in a positioning-information storage device 10. A positioning-information evaluation means 11 computes the mean value and the dispersion of the positioning information, it compares the mean value with own-calibration-position information, and it computes the average error of the positioning information so as to be sent to the means 8. The means 8 corrects a GPS positioning position from every moving body by means of the GPS positioning average error in the land-fixed station, and it computes the corrected position of a target. In addition, on the basis of information from an error-ellipse-information generation means 12, the generation position of an error ellipse image is computed. As a result, an error ellipse, the corrected position of the target at its inside and a radar live image can be displayed on a radar-image display means 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses GPS (Global) for position information of a moving object detected by a radar or sonar.
The present invention relates to a display device of a target position for superimposing and displaying position information of a moving body obtained by another position detecting means such as a Positioning System (L Positioning System) receiver or a Loran C receiver.

[0002]

2. Description of the Related Art Video information of a moving body (for example, a ship) obtained from active sensors such as radar and sonar is used as PPI.
(Plan Position Indication
For example, Japanese Patent Application Laid-Open No. 4-158290 is known as a known document regarding a technique of utilizing position information obtained by other position detecting means such as a GPS receiver or Loran C when displaying with n) or the like. is there.

In the above-mentioned publicly known document, a moving body, for example, the ship A is equipped with a GPS receiver to obtain position information of the ship itself, and a radar is installed to search for a target around the ship, and In a system for displaying image information on a display device, when clutter noise is now generated due to intense waves and the like, which obstructs the target display, the GPS receiver and the position information measured by this GPS receiver are also displayed. Other mobile having a wireless transmitter for transmitting, for example, the position information of the ship B transmitted from the ship B is received via the wireless receiver of the own ship, and from the image information by the radar of the own ship,
Position information from GPS receiver of own ship and GPS of ship B
The gain of a portion other than the position indicated by the position information by the receiver is reduced to obtain processed image information that is subjected to a process of suppressing clutter noise.

[0004]

When the positioning information of a GPS receiver mounted on a ship is used in order to accurately display the position of the ship on the sea by a radar of a land-based fixed station, the method described in the above document is used. As described above, if the positioning information of the GPS receiver is used as it is, the positioning information obtained by an ordinary GPS receiver includes a measurement error of about 100 to 200 meters. There was a problem that the position could not be displayed.

[0005]

A target position display device according to the present invention superimposes position information of a moving body detected by a radar with position information of a moving body obtained by another position detecting means. In the display device of the target position to be displayed,
Mobile identification code and mobile's GP transmitted from the mobile
From the information receiving means for receiving the GPS positioning information of the moving body measured by the S receiving means and the plurality of positioning information of the own station sequentially measured by the GPS receiving means of the own station, the average value and the variance thereof are obtained, Next, the GPS positioning information evaluation means for comparing the calibration position information of the own station that has been calibrated in advance with the average value of the GPS positioning information to evaluate the average error of the GPS positioning information, and the GPS positioning information evaluation means are evaluated. Error ellipse information generating means for generating error ellipse information for indicating that the target is present therein with a predetermined probability based on the dispersion of the positioning information, and for each moving object detected by the radar. A correction position of the mobile body obtained by correcting the average error of the positioning information obtained from the GPS positioning information evaluation means with respect to the GPS measurement position of the mobile body obtained from the information receiving means. A position symbol image generated as a symbol image, and an error ellipse image generated as an ellipse image based on error ellipse information obtained from the error ellipse information generating means centering on a corrected position of the GPS measurement position of the moving body, A raw image detected by the radar for each moving object corresponding to the position symbol image and the error ellipse image, a composite image created based on this live image, or an image of either the live image or the composite image. Image information processing means for generating superimposed image information and supplying the superimposed image information to the radar image display means.

[0006]

In the present invention, in order to accurately display the position of a moving body (for example, a ship) on the sea by a radar of a land fixed station, it is included in positioning information obtained by a GPS receiver mounted on the moving body. The following principle is used as a method for correcting the positioning error. First of all, G set up at my station on land
From a plurality of positioning information of the own station sequentially measured by the PS receiving means, the average value and the variance thereof are obtained, and then the pre-calibrated calibration position information of the own station and the average value of the GPS positioning information are compared. Evaluate the average error of GPS positioning information. Since the azimuth and the distance when the mobile body and the land fixed station are viewed from each GPS satellite can be considered to be approximately equal, the average error and the variance included in the GPS positioning information of the land own station are at sea. It is said that it can be commonly applied to the GPS positioning information of mobile bodies. According to this principle, the position of each moving body on the sea is displayed at the position where the average error included in the GPS positioning information is corrected, and based on the variance of the GPS positioning information, each moving body has a predetermined probability of being stored inside it. Since the error ellipse indicating the existence of the moving object is also displayed, the position of the moving body can be displayed more accurately than before.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a target position display device showing an embodiment of the present invention. In the figure, 1 is a GPS receiver mounted on a moving body (for example, a ship) including an antenna, and 2 is positioning information of the moving body received by the GPS receiver 1 and measured (specifically, longitude and latitude information). (Information) 3 is an identification code generator of a mobile body, and in the case of a ship, for example, international signal code (generally called a call sign, for example, JNPS, JK
3530 or the like) as a code, 4 is a radio for information transmission (having a built-in transceiver) including an antenna, and 5 is information related to the present invention transmitted from the radio 4 as radio waves. A part, that is, a part including the identification code and the positioning information of the mobile object to be positioned. Here, the GPS receiver 1 and the wireless device 4 are mounted for each moving body that is the object of position measurement, and in general, there are many such moving bodies in the display target area. Therefore, a plurality of the above 1 to 5 may exist at the same time, but in this example, the number of moving bodies is one.

Reference numerals 6 to 17 in FIG. 1 are devices on the side of a land fixed station having a radar transceiver, and are generally composed of many devices, but only the parts relating to the present invention are shown in the drawing. 6
Is a radio device (including an antenna) for transmitting information on the fixed station side, which is paired with the radio device 4 on the mobile body side, and 7 is an output signal of the radio device 6, which is an identification code and positioning of the mobile body. Information is included. Reference numeral 8 denotes an image information processing means, which performs various kinds of processing for generating image information to be supplied to the radar image display means 17. The configuration and operation of the image information processing means 8 will be described with reference to FIG. 9 is a GPS receiver for error evaluation on the fixed station side, including an antenna, 1
0 is a positioning information storage unit for storing a large number of positioning information sequentially measured by the GPS receiver 9 of its own station, 11 is a statistical processing of the large number of positioning information read from the positioning information storage unit 10, and The average value and the variance indicating the variation thereof are calculated, and the calibration position information of the local station and the average value of the GPS positioning information are compared to obtain the average error of the positioning information.

Numeral 12 is an error ellipse information generating means, which is an ellipse (generally Y-axis (longitude)) with a predetermined probability (for example, 95%) of the moving body based on the variance of the GPS positioning information obtained from the positioning information evaluating means 11. Error ellipse information is generated when the value of the variance and the value of the variance of the X axis (latitude) are different values, and an ellipse is present inside, and this information is supplied to the image information processing means 8. To do. Reference numeral 13 is a display identification code (for example, A01, A02,
... B01, B02 ..., etc.)
Reference numeral 14 is a radar antenna, 15 is a radar transmitter / receiver, and 16 is a radar signal processing means. The live image of the moving body obtained by the radar transmitter / receiver 15 is quantized and tracking processing is performed, and the target size, center position, A synthetic image such as a velocity vector is generated and supplied to the image information processing means 8 as needed. 17
Is a radar image display means, such as a PPI display,
Raw image from the radar transceiver 15 and image information processing means 8
Various images from are displayed on top of each other.

FIG. 2 is a diagram showing a configuration example of the image information processing means of FIG. Reference numeral 21 in FIG. 2 is an image memory (generally also referred to as a frame memory) for storing the image information displayed by the radar image display means 17, and reference numeral 22 is a positioning information evaluation for each mobile body with respect to the GPS measurement position from the wireless device 6. Means 1
The correction position calculation means for correcting the average error obtained from 1 and calculating the correction position of the target, 23 is the target correction position calculated by the correction position calculation means 22 on the display screen, and the position symbol ( For example, it is a position symbol image generating means for generating an image of + sign, and this output signal is written in the image memory 21 by a control signal from the image writing control means 28.

Reference numeral 24 is an ellipse image position calculating means for calculating the generation position of the error ellipse image based on the error ellipse information from the error ellipse information generating means 12 with the target correction position from the correction position calculating means 22 as the center, and 25 is a display. This is an error ellipse image generating means for generating an error ellipse image at the image display position calculated by the ellipse image position calculating means 24 on the screen, and this output signal is also the image memory 21 by the control signal from the image writing control means 28. Written in.

Reference numeral 26 is a code for calculating the position for generating the identification code image of the target based on the position information of the target raw image obtained from the radar transceiver 15 and the corrected position of the target from the correction position calculating means 22. The image position calculating means 27 is an identification code image generating means for generating an identification code image at the code image display position calculated by the code image position calculating means 26 on the display screen.
Written to 1.

When it is desired to display the radar composite image of the moving body in the image memory 21, the radar composite image of the moving body supplied from the radar signal processing means 16 is supplied from the image writing control means 28. Are sequentially written in the image memory 21 by the control signal of. Reference numeral 29 is an image read control means, which reads the image information written in the image memory 21 and supplies it to the radar image display means 17. FIG. 3 shows FIG.
2A and 2B are views showing a display example of the radar image display means of FIG. 1, in which FIG. 7A shows an example of a single target, and FIG.

The operation of FIG. 1 will be described with reference to FIGS. The GPS receiver 1 mounted on a moving body (for example, a ship) selects three satellites in a good receiving state from a plurality of satellites floating in outer space, receives GPS radio waves from these satellites, and positions the moving body. Get information 2. The positioning information 2 is supplied to the wireless device 4. Further, in the identification code generator 3, an identification code (international signal code in the case of a ship) unique to its own moving body is stored in advance in a storage element such as a ROM.
Based on the control signal from the S receiver 1, the identification code peculiar to the own mobile body is output to the wireless device 4. The mobile radio 4 transmits its own unique identification code and GPS positioning information in the form of radio waves 5 to the radio 6 provided in the land fixed station. The wireless device 6 of the land fixed station sequentially supplies the identification code and GPS positioning information for each moving body transmitted from each moving body to the image information processing means 8.

On the other hand, on the land fixed station side, a GP for error evaluation is used.
The S receiver 9 constantly receives radio waves from GPS satellites, and sequentially stores the obtained positioning information in the positioning information storage means 10. Although a predetermined number of predetermined positioning information is stored in the storage means 10, a new predetermined number of information is always stored by deleting the oldest information when new information is stored. This is because the GPS positioning information requires a relatively large number of positioning information for statistical processing because the measured values of the GPS positioning information always fluctuate and fluctuate depending on the operating positions of GPS satellites and the propagation state of radio waves. is there.

The positioning information evaluation means 11 calculates a variance indicating an average value and variations of a relatively large number of positioning information read from the positioning information storage means 10, and supplies this variance value to the error ellipse information generation means 12. To be done. Also, the GPS
The average value of the positioning information is compared with the self-calibrated position information, the average error of the positioning information is calculated, and this average error is supplied to the image information processing means 8. Considering the two positioning information obtained by the GPS receiver 1 of the mobile body and the GPS receiver 9 of the land fixed station, the azimuth and distance of the mobile body and the land fixed station viewed from each GPS satellite. Are approximately equal to each other, the average error and the variance of the positioning information can be commonly applied to the two positioning information, and the present invention displays the target position of the moving body based on this principle. Is.

The error ellipse information generating means 12 is based on the variance of the positioning information and has a probability of, for example, 95%, an ellipse indicating an error range within which the target exists (generally called an error ellipse, as described above, a circle). Including the case of.) Generate information,
This information is supplied to the elliptic video position calculating means 24 in the image information processing means 8.

In the image information processing means 8, the correction position calculating means 22 of FIG. 2 corrects the GPS positioning average error measured at the land fixed station to the GPS measurement position from each mobile body to calculate the target correction position. However, the position symbol generated by the position symbol image reproducing means 23 at this corrected position (+ in this example:
The symbol) video is written in the image memory 21. In addition, the elliptical image position calculation means 24 uses the target correction position as the center,
The position where the error ellipse image is generated is calculated based on the error ellipse information from the error ellipse information generating unit 12, and the error ellipse image generated by the error ellipse image generating unit 25 is written in the image memory 21 at this calculated position.

Here, the display position of the target raw image obtained by the radar transceiver 15 and the GPS positioning correction position of the target are extremely close to each other on the display screen, but they are not always in the same position. Often. This is because the radar detection information includes the azimuth error and the distance error due to the beam width of the radar antenna 14 and the transmission pulse width. Therefore, the code image position calculating means 26
Judges that the position information of the target live image by the radar and the target correction position by GPS which are extremely close to each other are based on the same target, and an identification code image of the target is generated from these two position information. A position (generally, a position near the live video is generally used) is calculated, and the identification code or the converted code generated by the identification code video generation means 27 is written in the image memory 21 at the calculated position. It should be noted that, if necessary, the composite image from the radar signal processing means 16 is also written in the image memory 21.

FIG. 3 shows an example in which the image read out from the image memory 21 in the image information processing means 8 and the live image from the radar transceiver 15 are overlapped and displayed on the radar image display means 17. The + sign shown inside the error ellipse indicates the target correction position, the hatched portion indicates the target live image, and "A0" displayed near the live image is displayed.
“1” and “B01” represent the converted identification codes of the target. Here, the target correction position indicated by + is 10 from the error of about 100 to 200 meters initially held by the positioning information from the GPS receiver. The error can be reduced to about 20 meters, and an ellipse indicating the error range is also displayed, and an identification code is displayed near the live image of the target, so that even when multiple targets approach each other, the targets can be individually targeted. Can be distinguished.

FIG. 4 is a partial block diagram of a target position display device according to another embodiment of the present invention. FIG. 4 shows an example in which the radar image display means 17A of the A station displays radar images obtained by three radar stations having the A station on land as the master station and the B station and the C station as slave stations. . Here, station A,
The locations of stations B and C are, for example, stations A and B in the Seto Inland Sea.
Station, C station, etc., such as an installation position in the case of being covered by a plurality of radar stations, the target monitoring areas of two adjacent radar stations are provided with a distance so that they overlap.

In FIG. 4, parts that can be easily inferred from FIG. 1 are omitted. In the figure, the subscript A of 14A to 17A indicates the device for station A, the subscript B of 14B and 15B indicates the device for station B, and the subscript C of 14C and 15C indicates the device for station C, respectively. . Reference numerals 31B and 31C in the figure denote signal transmission means such as a coaxial cable, and the target raw images and their position information transmitted from the radar transceiver 15B of the station B and the radar transceiver 15C of the station C are transmitted to the station A, respectively. To the coordinate conversion means 32B and 32C. The coordinate conversion means 32B and 32C coordinate-convert the raw images at the target detected coordinate positions of the B station and C station into the raw images at the display coordinates of the A station, respectively, and supply them to the radar signal processing means 16A and the radar image processing means 17A. . In addition to the above description, various auxiliary data (for example, the orientation of the TV camera) required by the mobile body monitoring system can be input to the input signal to the image information processing unit 8A.

When a surveillance system composed of a plurality of radar stations is constructed as shown in FIG. 4, any of a live image of a moving object detected by a radar, a composite image created based on the live image, or a live image and a composite image. This image is converted from the one obtained by the radar of the main station and the one obtained by the radar of the slave station which is separated from the master station and transmitted to the master station into preset common display coordinates. The images can be superimposed at the selected position.

In the example of FIG. 4, the common display coordinates are set as the installation position of the A station which is the main station, but the present invention is not limited to this. For example, the monitoring center of a plurality of radar stations is used. When there is between station A and station B,
The installation location of the monitoring center may be used as common display coordinates, and the raw images of the radars may be converted to the common display coordinates. Then, the GPS positioning correction position, the error ellipse, and the identification code can be displayed on the superimposed raw image or the combined image as in the case of FIG.

The present invention can perform the same function even if a Loran C receiver is used instead of the GPS receiver in the above embodiment.

[0026]

As described above, according to the present invention, the position information of the moving body detected by the radar is superimposed on the position information of the moving body obtained by the other position detecting means to display the target position. In the display device, the identification code of the moving body and the GPS of the moving body transmitted from the moving body by the information receiving means.
The GPS positioning information of the mobile body measured by the receiving means is received, and the average value and the variance are obtained from the plurality of positioning information of the own station sequentially measured by the GPS receiving means of the own station by the GPS positioning information evaluation means. Next, an average error of the GPS positioning information is evaluated by comparing the calibration position information of its own station, which is calibrated in advance, with the average value of the GPS positioning information, and the error ellipse information generating means evaluates the GPS positioning information evaluating means. Based on the dispersion of the positioning information obtained, error ellipse information for indicating that the target exists inside the target with a predetermined probability is generated, and for each moving object detected by the radar by the image information processing means. The GPS measurement position of the moving body obtained from the information receiving means, the GPS
A position symbol image generated as a symbol image showing a corrected position of the moving body obtained by correcting the average error of the positioning information obtained from the positioning information evaluation means, and a corrected position of the GPS measured position of the moving body as a center. An error ellipse image generated as an ellipse image based on the error ellipse information obtained from the error ellipse information generating means, and a raw image detected by the radar for each moving object corresponding to the position symbol image and the error ellipse image, Image information is generated by superimposing a synthetic image created based on the raw image or one of the raw image and the synthetic image, and the superimposed image information is supplied to the radar image display means. Therefore, it is possible to display a high-precision position of the moving body and an error ellipse indicating the error range of the moving body, as well as the live image and the synthetic image of the moving body.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a target position display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of image information processing means in FIG.

FIG. 3 is a diagram showing a display example of the radar image display means of FIG.

FIG. 4 is a configuration diagram of a target position display device according to another embodiment of the present invention.

[Explanation of symbols]

 1,9 GPS receiver 2 Positioning information 3 Identification code generator 4,6 Radio equipment 5,7 Identification code + positioning information 8 Image information processing means 10 Positioning information storage means 11 Positioning information evaluation means 12 Error ellipse information generation means 13 Identification Code conversion means 14 Radar antenna 15 Radar transceiver 16 Radar signal processing means 17 Radar image display means

Claims (3)

[Claims] 1. A display device for a target position, which displays the position information of a moving body obtained by another position detecting means by superimposing it on the position information of the moving body detected by a radar, which is transmitted from the moving body. Mobile unit identification code and mobile unit GP
From the information receiving means for receiving the GPS positioning information of the moving body measured by the S receiving means, and the plurality of positioning information of the own station sequentially measured by the GPS receiving means of the own station, the average value and the variance thereof are obtained, Next, a GPS positioning information evaluation unit that evaluates an average error of the GPS positioning information by comparing the calibration position information of its own station that is calibrated in advance with the average value of the GPS positioning information, and is evaluated by the GPS positioning information evaluation unit. Error ellipse information generating means for generating error ellipse information for indicating that the target is present therein with a predetermined probability based on the variance of the positioning information, and for each moving object detected by the radar. Correction of the mobile body obtained by correcting the average error of the positioning information obtained from the GPS positioning information evaluation means for the GPS measurement position of the mobile body obtained from the information receiving means A position symbol image generated as a symbol image that indicates the location, GP of the movable body
Regarding the error ellipse image generated as an ellipse image based on the error ellipse information obtained from the error ellipse information generating means centering on the corrected position of the S measurement position, and each moving body corresponding to the position symbol image and the error ellipse image, respectively. Of the live image detected by the radar, a composite image created based on the live image, or image information in which any one of the live image and the composite image is superimposed is generated, and the superimposed image information is generated. A display device for a target position, comprising: an image information processing means for supplying the radar image display means. 2. The identification code of each mobile body or the identification code of each mobile body based on the identification code of the mobile body and the GPS positioning information obtained from the information receiving means for each mobile body detected by the radar. An identification code image generated by using the converted conversion code as a code image, the position symbol image, the error ellipse image, and the live image of each moving body corresponding to the identification code image, and the live image, created based on the live image. 2. The display device at a target position according to claim 1, further comprising the image information processing means for generating image information in which a composite image or one of a live image and a composite image is superimposed. 3. A live image of a moving body detected by the radar, a composite image created based on the live image, or one of the live image and the composite image is obtained by a radar of its own station. And a coordinate conversion means for forming an image in which the one obtained by a radar of another station which is separated from the own station and transmitted to the own station is converted into a common display coordinate set in advance at a position where the image is superimposed. The target position display device according to claim 1 or 2, further comprising the image information processing means including the image information processing means.