JPS63174406A - Tracking antenna system - Google Patents

Abstract

PURPOSE:To realize continuous tracking for all loci, by providing a sub reflecting mirror or a first-order horn with movable structure so that a wave radiation axis can be rotated in a traverse direction, in an antenna system of AZ-BL mounting system. CONSTITUTION:The titled antenna system is constituted of an AZ rotating structure object 1 to rotate an antenna main body in 0-360 deg. around an AZ axis, an EL rotating structure object 2 to rotate the antenna main body around an EL axis, a main reflecting mirror 3, a sub reflecting mirror 4, and a tracking signal switching circuit 6. The sub reflecting mirror 4 is constituted so that the wave radiation axis 5 can be rotated in the traverse direction. And the rotating range of an elevation angle is expanded to a zenith-horizon in a direction opposite to the horizon-zenith of a conventional device in addition to that, and a tracking signal is switched in the circuit 6 so as to control an azimuth, an elevation angle, and a traverse angle respectively so that a floating body can be tracked continuously even in the neighborhood of the zenith.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tracking antenna device that automatically tracks flying objects such as artificial satellites and rockets.

[Conventional technology]

As an antenna driving device in a conventional device of this type, the most common method is the AZ-El mount method.

The AZ-EL1 mounting system configuration is shown in FIG. 4 (a+).

In the figure, 1 is a reflector forming the antenna aperture, 2
3 is a vertical axis (hereinafter referred to as the AZ axis), and 3 is a horizontal axis (hereinafter referred to as the EL axis) perpendicular to the AZ axis 2.

And the antenna is 0 to 360 degrees around 2 AZ axes.

It is configured to be able to drive from 0 to 90 degrees around the EL axis 3, and by combining the rotation angles of both axes, it is possible to direct the antenna in any direction.

[Problem that the invention seeks to solve]

However, in such a conventional Z-EL mounting system, as shown in FIG. 5, the amount of angular change in the flight path of the target object is Δe on the vertical plane including the target object.

Assuming that Δa is in the plane including the target perpendicular to the vertical plane, the rudder shaft 2 and IELEL axis antenna rotation angles are the original angles AZ and EL, and the rotation angle according to the amount of angle change of the target as ΔAZ, If ΔEL, ΔAZ−Δa/cos
EL −(11ΔE14. Δe
...It is expressed as (2). Therefore, in order to point in the direction of incoming radio waves from a target flying near the zenith, the rotational speed of the AZ axis 2 must be greater than or equal to the flight angular velocity Δa of the target (1/c).

sEL times), and at the zenith it becomes infinite and cannot be tracked. Therefore, this AZ-EL
With the mounting method, tracking was interrupted near the zenith.

On the other hand, as another method of the antenna driving device, FIG.
There is an X-Y method as shown in 1. In FIG. 4(b), 1 is a reflecting mirror forming the antenna aperture, 22.23
are horizontal axes (referred to as the X axis and the Y axis, respectively) that are orthogonal to each other. If the antenna is driven so that a rotation angle of 0 to 180° is obtained both around the X-axis and around the X-axis, directing in any direction is possible by combining the rotation angles of both axes.
In this case, high-speed rotation is required for targets flying near the extension line direction of the X-axis, but for targets near the zenith (9 (including the zenith) If it has speed, it can be tracked.

Therefore, when continuous tracking near the zenith is an absolute requirement, an antenna device of the X-Y mount type with the pole direction horizontally as described above was used.However, /IZ
- In the EL mount method, the center of gravity of the entire antenna remains constant with respect to rotation of the AZ axis, and the center of gravity moves only with rotation of the EL axis, but with the above X-Y mount method, rotation of either the X or Y axis The center of gravity also moves. As a result, the structure becomes complicated in adjusting the overall balance, and the weight increases.

This invention was made to solve the above-mentioned problems, and allows continuous tracking of all orbits, including those passing through the zenith, without interruption, using a general and inexpensive AZ-EL mount antenna. The purpose is to obtain a tracking antenna device.

[Means for solving problems]

The tracking antenna device according to the present invention is configured such that the sub-reflector or the primary horn is movable so that the radio wave emission axis can be rotated in the traverse direction (tracking), and the elevation angle rotation range is added to the horizontal to zenith of the conventional device. The zenith in the opposite direction
It is equipped with a switching circuit that optimally controls the azimuth (AZ> angle, ffn (EL) angle, and l-Lahas angle) so that it can be extended to the horizontal (reverse horizontal) and continuously track flying objects even near the zenith. be.

[Effect]

In this invention, the (rμ angle of the tracking target is not high,
In the range where the azimuth angle can be tracked sufficiently, the normal AZ-EL mount method (the traverse angle is at the center position) is used for tracking, and for buses that have a high elevation angle and pass near the zenith, when the elevation angle exceeds a certain angle, the AZ-EL mount method is used. Switch from axis tracking to tiger half-EL axis tracking to track near the zenith, and during this time the AZ axis slowly moves in the opposite direction (±180°) to the azimuth angle at which AZ-EL tracking becomes possible again after the tracking target passes the zenith. It moves and waits, which enables continuous tracking.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a conceptual diagram of a tracking antenna device according to an embodiment of the present invention.
is an EL rotation structure for rotating the Antilil main body around the EL axis, 3 is a main reflector, 4 is a sub-reflector equipped with a drive mechanism that can rotate the radio wave beam 5 in the traverse direction,
In particular, the EL rotating structure 2 has a normal O" (horizontal) to 90
Rotation range wider than ° (zenith), 0° (horizontal) to
It has a rotation range of 90° (zenith) to 180° (reverse horizontal). Further, 6 is a tracking signal switching circuit connected to each drive part of the tracking antenna to realize optimal tracking.

FIG. 3 shows a block diagram of the tracking antenna device according to this embodiment. In the figure, 7 is an angular error detector that detects angular error for automatic tracking, and 8 converts the detected angular error into a DC signal. angle error detector, 9 is elevation angle (EL)
10 is a sub-reflector control device that controls the l/Lahas angle, 11 is an AZ control device that controls the azimuth, 12 is an inversion circuit that inverts the polarity of the AZ error signal, and 13 is AZ.

This is a programming device that predicts the flight angle of the satellite from EL angle data (angle detection means not shown) and time data, and based on this predicts the flight angle of the satellite and controls each of the EL, AZ, and l-lapas angles. .

Figure 2 shows the satellite path and antenna azimuth.

2 is a diagram showing the relationship between elevation angles, where ■ indicates a range that can be continuously tracked with a normal AZ-EL mount, and ■ indicates an area that cannot be tracked with an AZ-EL mount due to a high elevation angle. The first pass (when the elevation angle is low) is in all areas from the appearance of the satellite to the satellite's submersion, and it can be tracked using the normal AZ-EL method, but the second pass (when the elevation angle is high) is in the area marked ■. , and continuous tracking is not possible with the AZ-EL method.

The second path tracking procedure in the device of this embodiment will be described below. In the second pass, tracking is performed using the AZ-EL method from the appearance of the satellite (point a) to the AZ-EL tracking limit (point b), during which time switch S1 in Figure 3 is set to side a, and switch S2 is set to side a. The switching is controlled, and when S3 is on the b side, the sub-reflector 4 is fixed at the center point by the program device 13, and automatic tracking in the normal state is performed.

Then, when point b is reached, switch S1 is set to b side.

Switching S2 to the b side and S3 to the a side, automatic tracking is performed using the EL angle and the traverse angle while passing through area ■ in Fig. 2, and during this time AZ is moved from point b to point C by the Progera J device 13. slowly move toward the 0 point (±180°) in the opposite direction of the azimuth. Here, as in the conventional device, El,
If the rotating structure has a rotation range of 0 to 90 degrees, AZ is b
It is necessary to move from point to point C, and the moving angle is too large to catch up (although it is impossible to do so, in this example device, the angle of movement is 0 to 90
Since it has a wide range of ~180°, AZ is from point b to C
It is sufficient to simply move the point to the 0 point, which is the opposite direction of the azimuth angle, and sufficient tracking becomes possible. Therefore, after the satellite passes near the zenith, the EL angle will exceed 90° (zenith), resulting in what is called inverted tracking.

Then, when it reaches point C, it enters the area ■, but since it is in the form of reverse tracking, switch S1 is on the a side and S2 is on the C side.
The EL is tracked, the switch S3 is set to the b side, and the sub-reflector 4 slowly returns to the center position in response to a command from the program device 13. As a result, the beam axis moves slowly in the traverse direction, but this is absorbed by the tracking system of Δ2, so it is not a problem. From then on, until point d (satellite immersion), Automatic tracking is performed in the same manner and inverted.In addition, in Fig. 3, the AZ error (ΔAZ)
SIECANT compensation circuit (ΔAZX 1 /cosE
L) is included in the Z control device 11.

In the above embodiment, the sub-reflector is driven to rotate the radio beam in the traverse direction, but this may be done by driving the primary horn.

Furthermore, although the above embodiment describes a method for tracking in the zenith direction using a ΔZ-EL mount, the present invention can be applied in exactly the same way to a method for tracking the horizontal direction of an X-Y mount method, The same effects as in the embodiment are achieved.

〔Effect of the invention〕

As described above, according to the present invention, in the cheapest and most common AZ-EL mount type antenna device, the sub-reflector or the primary horn has a movable structure so that the radio wave emission axis can be rotated in the traverse direction. At the same time, the elevation angle rotation range was expanded from horizontal to zenith to reverse horizontal, and the azimuth angle, elevation angle, and 1-Rahas angle were controlled by switching each according to the path of the projectile, so that the pole of the AZ-EL mount method described above This has the effect of allowing continuous tracking without interrupting tracking in a certain zenith direction.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a tracking antenna device according to an embodiment of the present invention, FIG. 2 is a diagram showing the relationship between a satellite passage path, an azimuth angle, and an elevation angle. Figure 4 shows the configuration of the conventional AZ-EL mount system, Figure 4(b) shows the configuration of the conventional X-Y mount system, and Figure 5 shows the configuration of the conventional AZ-EL mount system. Figure (AZ in al,
FIG. 3 is a diagram illustrating an approximate angle of EL. 1...AZ rotating structure, 2...EL rotating structure, 3
...Main reflecting mirror, 4...Sub-reflecting mirror, 5...Radio wave axis direction, 6...Tracking signal switching circuit, 7...Angle error detector, 8...Angle error detector , 9... EL control device, 10... Sub-reflector control device, 11... AZ control device, 12... Inversion circuit, 13... Program device. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An AZ-EL mount type tracking antenna device that automatically tracks flying objects, which includes an AZ direction rotation means for rotating the antenna body from 0 to 360 degrees around the AZ axis, and an AZ direction rotation means for rotating the antenna body around the EL axis. EL direction rotation means for rotating from 0 to 180° in the traverse direction; traverse direction rotation means for driving the sub-reflector or the primary horn so that the radio wave emission axis rotates in the traverse direction; When passing near the zenith exceeding the tracking limit of , the tracking operation is performed by the above-mentioned EL direction rotation means and traverse direction rotation means, and when passing through other areas, the above-mentioned tracking operation is performed by the above-mentioned EL direction rotation means and AZ direction rotation means. A tracking antenna device comprising a switching means for switching to. (2) The switching means includes an angle detection means for detecting the AZ and EL angles of the antenna body, and predicts the passage route of the flying object based on the AZ and EL angle data and time data, and 2. The tracking antenna device according to claim 1, further comprising a predictive determination means for determining a tracking limit of AZ-EL tracking according to a result.