JPH0716186U - Active radar reflector - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a small, inexpensive, multifunctional radar reflector to ensure navigation safety of ships. [Structure] Antenna and receiver for receiving radar waves of other vessels, code generator for encoding the ship's maneuvering status, modulator for modulating this code to radio waves, and transmitter for amplifying and transmitting this radio wave to radar , A transmission antenna.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an active radar reflector mounted on a ship, receiving radio waves from another ship's radar, and emitting a response signal for clearly displaying the own ship's position on the other ship's radar screen.

[0002]

[Prior art]

 Conventionally, radar reflectors (corner reflectors or lens-type reflectors) have been put into practical use for small fishing boats and small pleasure boats, which have low reflection efficiency against radar radio waves, in order to supplement the reflection efficiency.

[0003]

[Problems to be solved by the device]

 As is well known, the radar reflector is a substance that reflects radar radio waves, so it is necessary to increase its size in order to increase the reflection efficiency, and there is a drawback that it is unsuitable for mounting on small vessels. . In addition, since high surface precision is required for processing the reflective surface, it is expensive for its simple structure. Furthermore, conventional radar reflectors simply display the ship's position on the radars of other ships, and it is not possible to display the status of the ship itself (for example, seeking help).

The present invention has been made in order to solve such a drawback, and provides a small-sized radar reflector at a low cost, and also seeks the maneuvering state (direction change, etc.) of the own ship or rescue. The objective is to provide an active radar reflector that can display the information of other ships on the radar of other ships.

[0005]

[Means for Solving the Problems]

 The active radar reflector according to the present invention adds a code corresponding to the situation of the ship, which is obtained by a plurality of code generators provided, to the response radio wave and emits it.

[0006]

[Action]

 As soon as the receiver receives radar radio waves (pulses) from another ship, the transmitter sends back radio waves (pulses) that can be received by the radar to the radar, so this response radio wave appears as if it were on the radar screen of another ship. It is displayed like a reflected wave. Furthermore, by selectively adding a code to the response radio wave, it is possible to display the maneuvering status of the own ship on the radar screen of another ship.

[0007]

【Example】

 An embodiment of the active radar reflector of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a receiving antenna for receiving radio waves from another ship's radar, 2 is a receiver for amplifying received radar radio waves, 3 is a code generator, and 3a is a code generator for generating position information of the own ship. 3b is a code generator for generating a code for seeking rescue. 3c is a code generator for generating a code indicating the rudder state. 3d is a code generator for generating a code indicating the steering state. 3e is a code indicating a reverse state. A code generator 4 is a code selection switcher for switching the code generators 3a to 3e, 5 is a sawtooth wave generator, 6 is an FM modulator, 7 is a transmitter that sends back radio waves to a radar, and 8 is a transmission antenna. Is.

In such a configuration, the radio waves from the other ship's radar received by the receiving antenna 1 are amplified by the receiver 2 and are simultaneously sent to the code generators 3a, 3b, 3c, 3d, and 3e. The code generator 3a generates one pulse for each pulse of the received radar wave, and the code generator 3b generates 12 pulses. Further, FIG. 2 shows a timing chart of pulses generated in the code generators 3c, 3d and 3e. The code selection switch 4 selects any one of the code generators 3a, 3b, 3c, or 3e and connects it to the sawtooth wave generator 5. Is to switch manually. For example, the code generator 3c is selected when the ship is turning to the right, and the code generator 3b is selected when rescue is required. In the sawtooth wave generator 5, one sawtooth wave is generated for each pulse from the code generator 3. Therefore, when the code generator 3a is connected, one sawtooth wave is generated for each pulse of the received radar wave, and when the code generator 3b is connected, twelve sawtooth waves are generated. The FM modulator 6 is a sawtooth wave generated by the sawtooth wave generator 5 and generates a frequency-modulated microwave wave having a frequency of 9.5 GHz to 9.3 GHz assigned to the marine radar. To do. This microwave is amplified by the transmitter 7 and transmitted from the transmission antenna 8 to the radar.

Therefore, in the radar of another ship, 1 or 12 pulses are received each time one pulse of the radar wave is transmitted. That is, an image according to the code selected by the code selection switch 4 as shown in FIG. 3 is displayed on the radar screen of the other ship, and from this image, the maneuvering state of the ship equipped with the active radar reflector, etc. Can know FIG. 3 shows an example of the radar image at this time.

In the above embodiment, the code selection switch 4 is manually switched by the crew member, but it may be automatically switched by interlocking with the steering device and the propulsion engine.

Further, the number of pulses of the code generators 3b, 3c, 3d, 3e may be one or more, and is not limited to the number described here.

Further, as the frequency of the radio wave transmitted from the transmitter 7, 9.3 GHz to 9.5 GHZ is used because it is the case of the marine radar in the above-mentioned embodiment, but radars for other applications are used. If applicable, use a frequency compatible with that radar.

[0013]

[Effect of device]

 As described above, the active radar reflector according to the present invention is intended for radars with short wavelengths, so that the transceiver and code generator can be made compact. The high-sensitivity receiver and high-power transmitter ensure reliable radar display. Furthermore, since the ship's maneuvering information, etc. can be displayed on the radar screen of another ship, it has the effect of being useful for navigation safety not only for small ships but also for large ships.

[Brief description of drawings]

FIG. 1 is a block diagram of an active radar reflector according to an embodiment of the present invention.

FIG. 2 is a timing chart of codes generated by a code generator included in an active radar reflector according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an image of a radar that receives radio waves from an active radar reflector according to an embodiment of the present invention.

[Explanation of symbols]

1. Receiving antenna 2. Receiver 3.
Code generator 4. Code selection switcher 5. Sawtooth wave generator 6.
FM modulator 7. Transmitter 8. Transmitting antenna

Claims (1)

[Scope of utility model registration request] 1. An active radar reflector for emitting radio waves in response to radar radio waves, comprising a plurality of code generators activated by receiving radio waves as a trigger, and using a specified rescue code or marine vessel operation status code An active radar reflector characterized by emitting a response radio wave that is selectively added according to the operation status.