JPH06204732A - Driver for satellite antenna - Google Patents

Abstract

PURPOSE:To select plural satellites on a still orbit and to acquire the selected satellite. CONSTITUTION:A turning end 2b is directed to, e.g. the due north, and while a turning axis direction is tilted upward from a horizontal plane by a latitude a of an installed point, the polar axis 2 is fixed by a support base 1, an axial line of a support arm 4a is directed with a tilt by a prescribed angle beta (elevation angle difference between the sun and a reference satellite in a reference direction at a reference time) from a direction of an axial line of a support arm 4a orthogonal to a turning axis of the turning end 2b to fix the other end of the arm 4a to the turning end 2b thereby allowing an aperture of a parabolic antenna 4 to be directed in a direction of the angle beta. A turning angle for each satellite is preset to a changeover controller 3, which drives the turning end 2b of the shaft 2 in the operation through the reception of designation of a satellite. A turning angle epsilon of the turning end 2b for each satellite is expressed as epsilon-cos<-1>[{singammacos(90 deg.-alpha)}/cosbetacosalpha], where gamma is an elevating angle of an objective satellite based on a satellite in existence in the direction of the due south.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite antenna driving apparatus for switching and setting the direction of an antenna in each direction of a plurality of satellites in a geostationary orbit.

[0002]

2. Description of the Related Art For example, when a plurality of geostationary satellites placed in geostationary orbits are to be captured by one parabolic antenna, as in the case of receiving television broadcasting radio waves from a large number of satellites, the directions of the satellites are different from each other. There is a need for a satellite antenna drive that can set the antenna pointing direction.

It is possible to use an equatorial mount used for astronomical observation as the antenna driving device. That is,
As shown in FIG. 4, the equatorial mount includes a polar axis 31 that is rotationally driven in response to the rotation of the earth, and a red axis that rotates integrally with the polar axis 31 and that changes the declination angle according to the earth's orbit. The declination axis 32 is provided with the support arm 33a of the parabolic antenna 33, and the polar axis 31 is provided.
In the northern hemisphere, is set to the true north direction and is tilted from the main axis in the horizontal plane by an angle α determined by the latitude of the installation point. Since the target is a geostationary satellite, the predetermined angle P corresponding to the declination angle is set. The opening surface of the parabolic antenna 33 is set at a certain angle so as to direct the geostationary orbit, and the rotation angle is controlled so that the polar axis 31 rotates by an angle corresponding to the arrangement interval of the satellites.

[0004]

[Problems to be Solved by the Invention] However, in the equatorial mount,
The rotation angles of polar axis and declination axis are determined with reference to the center of the earth, but since geostationary satellites are closer than the sun, the influence of the earth's surface, which is not a perfect spherical surface, cannot be ignored, and the center of the earth is used as a reference. When obtaining the rotation angle, the error becomes large and correction is necessary. In addition, since it is necessary to consider the latitude and longitude of the installation point and the altitude and longitude of the satellite when setting the predetermined angle corresponding to the declination angle, it is expected that a considerably complicated adjustment operation will be required in actual operation. To be done.

In short, when the satellite antenna driving device is constructed so that the parabolic antenna is attached to the equatorial mount, the problem is how to set the predetermined angle corresponding to the rotation angle and the declination angle.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a satellite antenna drive device capable of switching and setting the pointing direction of the antenna by a simple adjustment operation.

[0007]

In order to achieve the above-mentioned object, the satellite antenna driving device of the present invention has the following structure. That is, the satellite antenna driving device of the present invention is a satellite antenna driving device that switches and sets the pointing directions of the antennas to the respective directions of a plurality of satellites in a geostationary orbit; A polar axis having a fixed end at one end and a rotating end at the other end; and a fixed end of the polar axis with the rotational axis direction of the rotating end oriented in the north-south direction, and from an angle dividing plane corresponding to the latitude of the ground installation point. A support base that is tilted and fixedly held; the direction of orientation of the rotation end of the polar axis is inclined by a predetermined angle (difference between the sun elevation angle and the satellite elevation angle in the reference direction at the time of reference) from the direction orthogonal to the rotation axis. A parabolic antenna that is fixedly held as shown above; the polar axis rotation angle for each satellite obtained from the latitude and longitude of the ground installation point and the altitude and longitude of each of the target satellites is preset,
A switching controller that receives a designated input from the satellite and rotationally drives the rotating end of the polar axis by a required polar axis rotation angle;

[0008]

Next, the operation of the satellite antenna driving apparatus of the present invention constructed as described above will be described. According to the present invention, the structure is equipped with a polar axis and a support base for supporting the polar axis on the ground in accordance with an equatorial mount, and the parabolic antenna is attached to the polar axis. Prepare the end, and at the time of installation, set the rotating axis direction of the rotating end of the polar axis to a predetermined direction so that the fixed end is fixedly held on the support base, and at the same time, the parabolic antenna has its directivity direction orthogonal to the rotating axis. It is fixed to the rotating end of the polar axis so as to be inclined by a predetermined angle from the direction, and during operation, the switching controller designated by the satellite only has to rotate only the rotating end of the polar axis. The "predetermined angle" is an angle corresponding to the declination angle in the equatorial mount. However, in the present invention, for example, in the northern hemisphere, the difference between the satellite elevation angle in the south direction and the spring and autumn sun elevation angle in the middle of the south. Is an angle defined as.

As a result, a plurality of satellites in the geosynchronous orbit can be switched and captured by a simple operation of simply designating the satellite without a complicated adjustment operation having a simpler structure than the equatorial mount.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a satellite antenna driving device according to an embodiment of the present invention. In FIG. 1, this satellite antenna drive device is basically composed of a support base 1, a polar axis 2, a switching controller 3 and a parabolic antenna 4.

The support base 1 includes, for example, a flat base 1a,
It is composed of a support column 1b which stands upright on the upper surface of the base 1a. The base 1a is horizontally arranged at the installation point. The column 1b has a U-shaped tip, and one end 2 of the pole shaft 2 is formed in the recess of the column 1b.
A is inserted and fixedly held by the bolt 1c.

The pole shaft 2 has one end 2a as a fixed end and the other end 2b as a rotating end. That is, a motor is built in the fixed end 2a, and the rotating shaft of the motor forms the rotating end 2b. The switching controller 3 controls the rotation drive of the built-in motor.

The switching controller 3 is inputted with, for example, a circuit for driving a motor built in the fixed end, a keyboard for inputting various data such as satellite designation, latitude and longitude of the installation point A, and earth radius R _e. It is composed of a simplified computer that calculates and stores the rotation angle of each satellite based on various data and issues a rotation drive command to the drive circuit according to the designation of the satellite.

The parabolic antenna 4 is attached to one end of the support arm 4a such that the antenna opening surface is orthogonal to the axis of the support arm 4a. The other end of the support arm 4a is formed in a U shape, and the rotary end 2b of the polar shaft 2 is inserted into the concave portion thereof and is fixedly held by a bolt 4b.

In the above structure, at the time of installation, the fixed end 2a is fixedly held by the bolt 1c in the recess of the tip of the column 1b, and the other end of the support arm 4a of the parabolic antenna 4 is fixed to the rotating end 2b by the bolt 4b. Hold it.

At this time, the polar axis 2 faces the rotation end 2b side in the northward direction in the northern hemisphere and in the southward direction in the southern hemisphere, as indicated by N (S) in FIG. hand,
In addition, the rotation axis direction is set by inclining upward from the horizontal plane of the angle α corresponding to the latitude of the installation point on the ground.

The support arm 4a of the parabolic antenna 4 is also provided.
Is set such that its axis is inclined by a predetermined angle β from the direction orthogonal to the rotation axis of the rotation end 2b of the polar axis 2. As a result, the parabolic antenna 4 is set in the true south direction in the northern hemisphere. In other words, in the Northern Hemisphere, the satellites that are located in the true south direction are the reference. Hereinafter, it will be described as being set in the northern hemisphere.

The predetermined angle β is, as shown in FIG.
It is the angle difference between the sun elevation angle δ of the spring and autumn equinox during mid-south and the elevation angle γ _{1 of the} satellite 22 in the true south direction at the installation point A in the northern hemisphere above ₁ , which corresponds to the declination angle in the equatorial mount. , The contents are different.

This predetermined angle β is specifically, the installation point A
Latitude α (but -α in the Southern Hemisphere), radius R of the Earth 21
_e and the distance R _S between the satellite 22 and the center of the earth.

That is, the reference satellite 2 located just south of the installation point A
Since the distance R _{SAT1 to} 2 is given by Equation 1, the elevation angle γ ₁ looking at the reference satellite 22 from the installation point A is Equation 2, and the sun elevation angle δ is 90 ° −α from FIG. β can be obtained by Equation 3.

[0021]

## _EQU1 ## R _SAT1 = (R _e ² + R _S ² -2R _e R _S cos α) ^1/2

[0022]

Γ ₁ = cos ⁻¹ {(R _SAT1 ² + R _e ² −R _S ² ) / 2R _e R _SAT1 } -90 °

[0023]

[Formula 3] β = γ ₁ − (90 ° −α)

FIG. 3 shows the relationship between the latitude of the installation point and the elevation angle of the geostationary satellite and the sun at the spring and autumn equinoxes in the southward direction. The difference between both elevation angles is the predetermined angle β.

In operation, the rotating end 2b of the polar shaft 2
The target satellite is switched and captured by rotating the satellite. The rotation angle can be obtained as follows with reference to the satellite 22 existing in the true south direction.

That is, the distance R _SAT2 from the installation point A to the target satellite is the latitude α of the installation point A and the radius R of the earth 21.
_e , the distance R _s between the reference satellite 22 and the center of the earth, and the longitude difference θ between the installation point A and the target satellite (Equation 4), and thus the elevation angle γ ₂ of the target satellite is Equation 5
The rotation angle ε is given by the following equation 6.

[0027]

## _EQU00004 ## R _SAT2 = (R _e ² + R _S ² -2R _e R _S cos α cos θ) ^1/2

[0028]

Γ ₂ = cos ⁻¹ {(R _SAT2 ² + R _e ² −R _S ² ) / 2R _e R _SAT2 } −90 °

[0029]

[Equation 6] ε = cos ^-1 [{sinγ ₂ −sinβ cos (90 ° −α)} / cos β cos α]

Therefore, in this embodiment, the north-south direction N
(S) and the angle α and β are set only during the installation work. Therefore, the north-south direction N (S) is set by using a compass and a leveling magnet with a correction value added to the angle α and β. The setting of the rotation angle ε for each satellite is performed as one of the setting work by the manual calculation and the numerical table (Fig. 3).
The simplified computer (1) is operated (Equations 4 to 6) and stored.

As a result, when the satellite is designated by operating the key board of the switching controller 3 during operation, the rotary end 2b is rotationally driven by a required angle, and the parabolic antenna 4 is automatically switched to a desired satellite direction for directing. Can be done.

The switching controller 3 may be provided with a memory in place of the simplified computer so that the rotation angle of each satellite calculated externally can be stored and the necessary rotation angle can be read out according to the designated input. Of course.

Here, the numerical error increases as the latitude of the installation point A increases, but for example, in Japan (4 latitudes north)
(5.5 ° or less), the error is 0.3 ° or less, which is small as a whole, which is not a problem in practical use.

[0034]

As described above, according to the satellite antenna driving device of the present invention, a parabolic antenna is provided on the polar axis, which has a polar axis and a support for supporting the polar axis on the ground, following the equatorial mount. However, a pole shaft with one fixed end and the other end being a rotating end is prepared, and at the time of setting, the rotating shaft direction of the rotating end of the polar shaft is set to a predetermined direction to support the fixed end. The parabola antenna is fixedly held on the table, and at the same time, the polar axis is rotated so that the parabolic antenna is tilted by a predetermined angle (the elevation difference between the sun and the satellite in the reference direction at the time of reference) from the direction orthogonal to the rotation axis. Since it is fixedly held at the end and the switching controller designated by the satellite only needs to rotate only the rotating end of the polar axis during operation, it has a simpler structure than the equatorial mount and does not require complicated adjustment operation. Simple operation to simply specify the satellite There is an effect that can be captured by switching a plurality of satellites in geostationary orbit at only.

[Brief description of drawings]

FIG. 1 is an external configuration diagram of a satellite antenna driving device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of calculating a predetermined angle β and a rotation angle of a rotation end 2b.

FIG. 3 is a diagram showing the relationship between the latitude of the installation point and the elevation angles of the sun and satellite during the spring and autumn equinox when facing south.

FIG. 4 is a conceptual view of the appearance when a parabolic antenna is set on the equatorial mount.

[Explanation of symbols]

From the satellite R _e earth radius R _S geocentric present in first support platform 1a base 1b strut 2 polar 2a fixed end 2b rotating end 3 switch controller 4 parabolic antenna 4a supporting arm 21 earth 22 reference direction (due south direction) Distance to satellite α Latitude of installation point β Reference time Elevation difference between sun and satellite in reference direction γ Satellite elevation angle δ Sun elevation angle

Claims (1)

[Claims] 1. A satellite antenna drive apparatus for switching the direction of an antenna to each direction of a plurality of satellites in geostationary orbit; the satellite antenna drive apparatus has one end fixed and the other end. And a polar axis having a rotating end; and a support for fixing and holding the fixed end of the polar axis with the rotating axis of the rotating end oriented in the north-south direction and tilted from the horizontal plane at an angle corresponding to the latitude of the ground installation point. A table; a predetermined angle from the direction orthogonal to the rotation axis at the rotation end of the polar axis (difference between the sun elevation angle and the satellite elevation angle in the reference direction at the time of reference)
A parabolic antenna that is fixedly held in a tilted direction; the polar rotation angle of each satellite obtained from the latitude and longitude of the ground installation point and the altitude and longitude of each of the target satellites is preset. A satellite antenna drive device, comprising: a switching controller that receives a designated input from a satellite and rotationally drives a rotating end of the polar axis by a required polar axis rotation angle.