JPS5923270A - Radar device - Google Patents

Abstract

PURPOSE:To detect many target positions different in backscattering coefficients, and to detect a quality of a target, by rotating in one body an antenna aperture for emitting various radio waves different in directions. CONSTITUTION:Radio waves different in frequency and polarization, respectively are emitted from three sets of antenna apertures 17-19 in different directions, and these apertures 17-19 are rotated is one body centering around the rotary shaft. According to this constitution, different kind of target positions is detected by a calescence point on a sweep trace of PLAN POSITION INDICATOR with respect to the antennas 17-19, and the quality of a target is detected by a difference of its luminance.

Description

[Detailed description of the invention] The present invention relates to a radar device.

Conventionally, this type of radar rotates the antenna while emitting beam-like pulses with sharp directivity from an aperture antenna, aligns the sweep line on the cathode ray tube with the antenna, and determines the target position (antenna/target). The distance and direction between the two points are displayed on a CRT (PPI: pla
ne position 1 indicator). In this method, the center of the CRT is the position of the radar, the distance is determined in the radial direction, and the direction is determined in the circumferential direction. By displaying a bright spot only when the reflected signal returns, it is possible to reach the target on the CRT surface. It simultaneously displays distance and direction information. In this case, the antenna is 36
It takes about 2 to 10 seconds to rotate 0 degrees. Therefore, a long-afterglow cathode ray tube was used to make the bright spot shine on a certain target until it shines again (until the antenna rotates 360 degrees).

Furthermore, in order to detect targets whose positions (distance, direction) change rapidly, multiple aperture antennas were used to increase the frequency of target detection. However, since a certain frequency and polarization were used, it was possible to detect certain types of targets (targets whose backscattering coefficient was small at that frequency and polarization).

The present invention emits waves of different frequencies and polarizations in different directions from a plurality of aperture antennas, and rotates them as one, thereby emitting waves of a specific frequency or polarization. Using it, you can detect it! The present invention provides a radar device that can detect the position of a target with 4Ifi L and can know the properties of the target based on the difference in backscattering coefficients.

The present invention aims to accurately detect targets having various backscattering coefficients.

The antenna section of this device consists of multiple aperture antennas, each of which is placed in a different direction, and each emits a different frequency and polarization while rotating as a unit. let

On the other hand, sweep lines corresponding to each aperture antenna in a 1:1 ratio are prepared on the cathode ray tube surface, and these sweep lines are rotated in synchronization with each aperture antenna. Then, using the conventional P2 method, the target position [U information (azimuth,
Distance) is displayed by a bright spot, but at that time, radio waves of different frequencies and polarization planes (the combination of these is determined depending on the nature of the target to be detected) are used.
Not only is it possible to detect the positions of a large number of targets with different backscattering coefficients, but it is also possible to know the properties of the targets based on the differences in the backscattering coefficients.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram of the entire device. The transmission wave 10 generated by the transmitting section 4 passes through the transmission/reception switching section 3 and becomes a transmission signal 9 from a plurality of antennas (three in this case,
Aperture antenna (A, B, C) 17.18.19 (see Fig. 2) having a rotating shaft 20 that rotates in the antenna rotating section 2
radio waves of different frequencies and polarizations are emitted in different directions.

The emitted signal from the target is received by the aperture antenna integrated with the transmitting and receiving unit, and the received signal 9 passes through the transmitting/receiving switching unit 3 and is detected and amplified in the receiving unit as the received signal 1■. The signal is modulated and input as a display signal 14. The display unit 6 is of the PPI type and simultaneously displays distance information and position information of the target on the cathode ray tube surface. Each aperture antenna and the sweep line on the cathode ray tube surface (in this case, 3
books) correspond to each other. The trench includes a transmitting section 4, a receiving section 5, a transmitting/receiving switching section 3, an antenna rotating section 2, and a display section 6.
For example, the synchronization signals 12, 13, 16 from the synchronization signal generator 7
．． 8 and 15.

Now, there are three aperture antennas, each labeled A.

B and C, radio waves with a frequency of 7 + polarization P are emitted from A, fB + PB, and fo from C.
Assuming that radio waves of Po are emitted (select this combination appropriately depending on the target you want to detect), A, B
, C, the position of the target can be known from the position of the bright spot, and the nature of the target can be known from the slight difference in brightness.

As explained above, the present invention improves the backscattering coefficient by emitting waves of various frequencies and polarizations in different directions from a plurality of aperture antennas and rotating them as one unit. Not only can the positions of a large number of different targets be detected, but also the properties of the targets can be known based on the differences in backscattering coefficients.

[Brief explanation of the drawing]

FIG. 1 is a complete block diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of an antenna section formed by three parabolic antennas. 1...Antenna section, 2...Antenna rotating section, 3...Transmission/reception switching section, 4...Transmission 1
311. 5...Reception section, 6...Display section, 7...Synchronization signal generation section, 17-19...
...Aperture antenna, 20...Rotation axis. Figure 1 Figure 2

Claims (1)

[Claims] A radar device characterized by having a plurality of aperture antennas that rotate together while emitting radio waves of various polarizations and frequencies in different directions to an antenna section.