JPS62118279A - Combined radar for marine vessel - Google Patents

Abstract

PURPOSE:To improve the identification of a small marine vessel, etc., by taking a correlation of a radar video by a horizontal polarization and a radar video by a vertical polarization, and eliminating or decreasing a sea clutter. CONSTITUTION:A horizontal polarization use antenna 1a executes an emission as a horizontal polarization, and a radar antenna 1b for a vertical polarization executes an emission as a vertical polarization. A signal by the horizontal polarization, which has been received by this antenna 1a, and a signal by the vertical polarization, which has been received by the antenna 1b are returned to a transmitter-receiver 3a and 3b through the respective exclusive waveguides in a double rotary joint 2. also, a correlator 4 brings a radar video by the horizontal polarization and a radar video by the vertical polarization to a phase adjustment and forms a composite video. In this case, the antenna 1a and 1b are rotated by shifting the phase by 180 deg., therefore, whenever both the antennas 1a, 1b are rotated by 1/2, the radar video is updated. Accordingly, the updating time of the radar video is shortened to 1/2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to radar, and particularly to a combined radar for ships that is most suitable for application to safe navigation of ships.

[Conventional technology] Radars traditionally used for safe navigation of ships are:
The rotation speed of the radar antenna is approximately 2 Or, p.

m, and the time required for one rotation of the radar antenna, that is, the time required for one rotation of the sweep line, is about 3 seconds, so it can be used for motor boats sailing at high speeds, or even at low speeds, when sailing in a curved line. In the case of ships that are turning or turning, the reflected signals received by the radar are discrete, making it difficult to track those ships. Furthermore, if two independent radars are to be used for such a purpose, the limited space on the radar mast will result in equipment difficulties. Furthermore, it is very difficult to identify small vessels among sea clutter caused by waves.

[Problems to be solved by the invention] From the above, the rotation speed of the radar antenna can be reduced to about 2° compared to the conventional one.
From r and plm, the rotational speed of the rotary drive device is equivalently increased to approximately 4 Or, p, and m, and the time required for one rotation of the radar antenna, that is, the time required for one rotation of the sweep line, is equivalently approximately approximately The aim is to shorten the time from 3 seconds to approximately 1.5 seconds to improve tracking performance for multiple ships, and also to solve equipment problems due to the limited space on the radar mast that occurs when trying to use two independent radars. There is a strong demand for radar to improve the identification performance of small vessels by eliminating sea clutter and reducing sea clutter by taking advantage of the difference between horizontally polarized sea clutter and vertically polarized sea clutter. .

The present invention was made in response to the above-mentioned demands, and its purpose is to improve the ability to track other ships,
It is an object of the present invention to provide a highly reliable combined radar for ships, which can eliminate difficulties in equipment due to limited space on a radar mast and improve identification performance for small ships.

[Means for Solving the Problems] In order to achieve the above object, the combined radar for ships of the present invention combines a horizontally polarized radar antenna and a vertically polarized radar antenna back to back and rotates as a unit. An antenna, a double rotary joint that provides a dedicated waveguide for each of the horizontally polarized radar antenna and vertically polarized radar antenna, two sets of transmitters and receivers with the same specifications, and a horizontally polarized radar video A correlator that adjusts the phase of the vertically polarized radar video and the vertically polarized radar video to form a composite video, and at the same time correlates the horizontally polarized radar video and the vertically polarized radar video to remove and reduce sea clutter to obtain high quality radar video. and a radar indicator that displays high-quality composite video.

[Function] According to the above-described combined radar for ships of the present invention, the received signals from each radar antenna are simultaneously displayed in a combined manner in each area obtained by dividing the radar screen into two, so that the radar screen can be divided into two and the received signals from each radar antenna can be simultaneously displayed. The radar video is updated every time the antenna rotates 360 degrees, and the radar video update time is 1/2 that of conventional methods.
It is shortened to .

Therefore, the ability to track other ships is improved twice as much as in the past. Further, since sea clutter is different between horizontally polarized radar video and vertically polarized radar video, sea clutter can be removed and reduced by correlating both radar videos in a correlator. This improves the identification performance of small vessels.

[Example] Hereinafter, an example of a combined radar for a ship according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the functions of a combined radar for ships according to the present invention, and FIG. 2 is a diagram showing the equipment configuration of the combined radar for ships.

In the figure, the transceiver 3a and the transceiver 3b have exactly the same specifications and operate independently, and the generated pulses pass through dedicated waveguides in the double rotary joint 2, and are transmitted to the horizontally polarized radar. It is supplied to the antenna (A) 1a and the vertically polarized radar antenna 11 (B) 1b. This horizontally polarized radar airborne 1! i! (A) 1a and the vertically polarized radar antenna (B) 1b are arranged back to back and rotate together. Then, the horizontally polarized radar antenna (A)la emits horizontally polarized waves,
The vertically polarized radar antenna (B) 1t) emits vertically polarized waves. Radar antenna for horizontal polarization (A>la
The horizontally polarized signal received by the vertically polarized radar antenna (B) 11) and the vertically polarized signal received by the vertically polarized radar antenna (B) 11) Through the transmitter/receiver 3a and transmit/receive!
Coming back to 1i3b. Further, the correlator 4 adjusts the phases of the horizontally polarized radar video and the vertically polarized radar video to form a composite video. Radar antenna for horizontal polarization (A) Ia and radar antenna for vertical polarization (B) 1
Since it rotates 180 degrees out of phase with b, the rain antenna (
The radar video is updated every time A) 1a and (B) 1b rotate 1/2. In other words, the radar video update time is 1
/2 (data rate doubles). Also,
Since sea clutter due to horizontal polarization and sea clutter due to vertical polarization are different, the sea clutter is removed and reduced by correlating the horizontal polarization radar video and the vertical polarization radar video. A high quality composite video is then displayed on the radar indicator 5. As a result of the above, it is possible to double the data rate and improve identification performance for small vessels by reducing sea clutter removal.

[Effects of the Invention] As explained above, according to the combined radar for ships of the present invention, the following effects can be significantly obtained.

(a) Since radar video can be updated in half the time compared to conventional methods (doubling the data rate) without reducing the number of pulse hits per rotation of the radar antenna, tracking performance of target ships is improved and intelligence is increased. It can be applied to radars for unmanned ships such as other ships.

(b) Since only one rotary drive device is required, the limited space on the radar mast can be handled in the same manner as before.

(C) Compared to the case of using two radars, there is no need to set the rotation period.

(d) Compared to the case where two radars are used, there is no need to correct the coordinates due to differences in the equipment positions.

(e) Compared to the case of using two radars, since radio waves are transmitted from one point, the direction, distance, etc. of ships at close range can be accurately captured.

(f) Since sea clutter is different between horizontally polarized radar video and vertically polarized radar video, it is possible to eliminate and reduce sea clutter by correlating both radar videos, which improves the identification performance of small ships. You can improve your performance.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the combined radar for ships according to the present invention. Figure 1 is a block diagram showing the functions of the combined radar for ships, and Figure 2 is a block diagram of the combined radar for ships. It is a diagram showing the equipment configuration. 1a...Antenna for horizontally polarized waves (A), 1b...Antenna for vertically polarized waves (B), 2...Double rotary joint, 3a...Transmitter/receiver, 3b...Transmit/receive Machine, 4...
- Correlator, 5... Radar indicator.

Claims (1)

[Claims] an antenna that rotates as a unit by combining a horizontally polarized radar antenna and a vertically polarized radar antenna back to back;
A double rotary joint that provides dedicated waveguides for each of the horizontally polarized radar antenna and vertically polarized radar antenna, two sets of transmitters and receivers with the same specifications, and horizontally polarized radar video and vertically polarized radar antenna. A correlator that adjusts the phase of the radar video to form a composite video, and at the same time correlates the horizontally polarized radar video with the vertically polarized radar video to remove and reduce sea clutter to obtain a high quality radar video. What is claimed is: 1. A combined radar for ships, comprising: a radar indicator that displays a composite video.