JPH0744376B2 - Onboard antenna drive controller for ship stations for satellite communication - Google Patents

Description

The present invention relates to a satellite for driving and controlling the elevation angle and azimuth angle of an onboard antenna in order to correctly orient the onboard antenna of a ship station for satellite communication toward the satellite. The present invention relates to a shipboard antenna drive control device for a communication ship station (hereinafter, referred to as a shipboard antenna drive control device unless special cases).

(Prior Art) Conventionally, in order to direct an onboard antenna of a ship station for satellite communication to a satellite, information on the position of the ship and the traveling direction of the ship is obtained from a navigation device, which is a device unique to the ship station, such as a gyro compass. And calculate the elevation angle and azimuth angle of the onboard antenna with respect to the satellite based on these information,
The elevation angle and azimuth angle of the onboard antenna are changed.

(Problems to be Solved by the Invention) However, in the conventional onboard antenna directing method, the elevation angle and the azimuth angle of the onboard antenna are indirectly obtained based on the information from the navigation device and the position of the satellite given in advance. Since the antenna is driven and controlled, there are drawbacks as described below.

In other words, the drive control unit of the ship's antenna must be connected to the navigation device of the ship with a cable, etc., and a large amount of outfitting work is required for this cable wiring, resulting in an increase in cost and a prolonged construction period. There are drawbacks.

In addition, the drive control data for the onboard antenna is indirectly obtained from the information obtained from the navigation device, and the accuracy of the drive control data depends on the performance of the navigation device, and the pointing accuracy of the onboard antenna decreases. There is a drawback that sometimes.

Similarly, the drive control data for the onboard antenna is obtained from the information from the navigation system of the ship, so if a failure such as a malfunction occurs in the navigation system, the onboard antenna can be correctly pointed toward the satellite. There is a drawback that the satellite communication is lost and satellite communication cannot be performed.

Furthermore, since the satellite position is determined to be immovable in order to obtain the elevation angle and azimuth angle of the onboard antenna, it is based on the position given in advance, so if the satellite position fluctuates due to perturbation, etc. There is a drawback that an error may occur in the pointing direction.

An object of the present invention is to solve the above-mentioned drawbacks, and it is possible to reduce the outfitting work, reduce the cost and shorten the construction period, and use the onboard antenna for high-precision satellites. It is an object of the present invention to provide a shipboard antenna drive control device for a satellite communication ship station that can be directed in any direction.

(Means for Solving the Problem) The above problem is to provide a plurality of onboard antennas that are provided at predetermined intervals in the longitudinal direction of a ship station for satellite communication, and transmit electromagnetic waves from each of the onboard antennas to the satellite. Distance measuring means for receiving the reflected waves from the satellites by the respective onboard antennas to measure the distances between the respective onboard antennas and the satellites, and the respective onboard antennas based on the distances measured by the distance measuring means. Is a means for calculating an elevation angle and an azimuth angle which are accurately directed to the satellite, and an elevation angle and an azimuth angle of each of the onboard antennas are driven based on the calculation elevation angle and the calculation azimuth angle by the operation means to cause the onboard antennas to The problem can be solved by providing a driving means for directing to the satellite.

(Operation) According to the present invention, first, the distance measuring means directly measures the distance between each of the plurality of onboard antennas and the satellite. Then, the elevation angle and the azimuth angle of the onboard antenna are calculated according to the geometrical conditions based on the measurement results. Finally, the elevation angle and azimuth angle of the onboard antenna are changed and driven based on the obtained elevation angle and azimuth angle.

According to the present invention, the distances between a plurality of onboard antennas and satellites are directly measured, and the onboard antennas are drive-controlled based on the measurement results. It is possible to improve the pointing accuracy of the onboard antenna without deteriorating due to the performance of the above and the perturbation of the satellite. In addition, the onboard antenna drive control device can be provided near the onboard antenna, and the outfitting work can be reduced, which can reduce the cost and the construction period.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of an onboard antenna drive control device of this embodiment, FIG. 2 (a) is a side view of a ship station of this embodiment, and FIG. 2 (b) is a plan view of a ship station of this embodiment. Is.

As shown in FIG. 2, the ship station 1 for satellite communication has a total length of 150.
It consists of a vessel measuring 16 m and a total width of 16 m. Ship Station 1
The onboard antenna 10 and the second onboard antenna 20 of the ship station 1
Are provided at a predetermined distance C in the longitudinal direction. This distance C is set to be as large as possible so as to increase the resolution when obtaining the azimuth angle in which the communication satellite A is considered from the ship station 1 as described later. Further, the first and second onboard antennas 10 and 20 are arranged so as not to block the communication satellite A.

As shown in FIG. 1, the shipboard antenna drive controller of this embodiment has the following configuration. That is, the first transmitter 11 and the first receiver 12 connected to the first shipboard antenna 10, respectively, and the second transmitter 21 and the second receiver connected to the second shipboard antenna 20, respectively. Machine 22, a code generator 30 for generating a ranging code for modulating a carrier wave transmitted from the transmitters 11 and 21 shown in FIGS. 1 and 2, and a first or second transmitter.
A first detector 13 for detecting a distance measuring code from a carrier wave transmitted from 11, 21 to the communication satellite A, reflected by the communication satellite A, and received by the first or second receiver 12, 22; Bits between the second detector 23 and the ranging code transmitted from the first or second transmitter 11, 21 and the ranging code received by the first or second receiver 12, 22 A code bit difference measuring device 31 for detecting a difference (phase difference), and the present invention for measuring the distance between the first or second onboard antenna 10 or 20 and the communication satellite A from the bit difference obtained by the code bit difference measuring device 31. The distance measuring function as the distance measuring means and the first or second onboard antenna 1 from this measured distance
Based on the controller 32 having a calculation function as a calculation means of the present invention for calculating the elevation angle and the azimuth angle at which 0 and 20 are accurately directed to the communication satellite A, and the elevation angle and the azimuth angle calculated by the controller 32. The first or second on-board antenna 10 or 20 comprises a first driver 14 and a second driver 24 as driving means of the present invention for changing and driving the elevation angle and azimuth angle, respectively.

Here, the outline of the arithmetic function in the controller 32 described above with reference to FIG. 3 or FIG. 4 will be described.

First, referring to FIG. 3, first and second onboard antennas
A case will be described in which the elevation angles 10 and 20 accurately point to the communication satellite A are calculated. d is the distance between the first onboard antenna 10 and the communication satellite A, and θ is the first for pointing the communication satellite A.
Assuming that the elevation angle of the on-board antenna 10 is R _E , the radius of the earth is h, and h is the altitude of the communication satellite A, the following equation holds between d and θ.

Where R _E and h are known and d is the controller described above.
It becomes known by being measured by 32 distance measuring functions. Therefore, the elevation angle θ can be obtained according to the equation (1).

Next, referring to FIG. 4, the first and second onboard antennas
A case in which the azimuths 10 and 20 accurately point to the communication satellite A are calculated will be described. a ₁ is the distance between the first onboard antenna 10 and the communication satellite A, a ₂ is the distance between the second onboard antenna 20 and the communication satellite A, and θ ₁ is the first when pointing to the communication satellite A.
Angle of elevation of the onboard antenna 10 of, the elevation angle of the second onboard antenna 20 when θ ₂ is directed to the communication satellite A, b ₁ is the projection distance of a ₁ onto the horizontal plane, and b ₂ is the projection distance of a ₂ onto the horizontal plane. Then, a ₁
And b ₁ and a ₂ and b ₂ have the following equations.

b ₁ = a ₁ cos θ ₁ and b ₂ = a ₂ cos θ ₂ a ₁ and a ₂ are known as measured values, and θ ₁ and θ ₂ are the above-mentioned (1)
Since it can be obtained from the equation, b ₁ and b ₂ can be obtained.

Here, as described above, C is the distance between the first onboard antenna 10 and the second onboard antenna 20, α ₁ is the azimuth angle of the first onboard antenna 10 for pointing the communication satellite A, and α ₂ Is the azimuth angle of the second onboard antenna 20 for pointing the communication satellite A, and between α ₁ and b ₁ , b ₂ , c and between α ₂ and b ₁ , b ₂ , c The following formula holds.

Since b ₁ , b ₂ , and c are known in the equation (1), the azimuth α
₂ is required. Similarly, in the equation (2), b ₁ , b ₂ , c
Is known, the azimuth α ₁ is determined.

Next, the operation of the onboard antenna drive controller of this embodiment will be described with reference to FIG. Here, the first onboard antenna 10 will be described, but the same applies to the second onboard antenna 20.

First, a distance measuring code is generated from the code generator 30, the carrier wave is modulated by this distance measuring code, and the modulated carrier wave is transmitted from the first transmitter 11 toward the communication satellite A. This carrier wave is reflected by the communication satellite A and returned to the first receiver.
Received at 12. The received carrier wave is input to the second detector 13 and the ranging code is detected. Then, by utilizing the sufficiently long code length of the ranging code and good characteristics of the catching property, the bit difference between the transmitted ranging code and the received ranging code is measured by the code bit difference measuring device 31. It From this pit difference, the controller 32 measures the distance between the first onboard antenna 10 or the second onboard antenna 20 and the communication satellite A. Further, the controller 32 calculates the elevation angle and the azimuth angle according to the above-mentioned calculation formulas (1) to (3) based on the measured distance. To obtain this calculated elevation angle and calculated azimuth angle,
The first driver 14 is driven to change and control the elevation angle and azimuth angle of the first onboard antenna 10.

As described above, in this embodiment, the elevation angle and the azimuth angle of the first and second onboard antennas 10 and 20 are calculated based on the distance between the first and second onboard antennas 10 and 20 and the communication satellite A. In this way, the elevation angle and the azimuth angle of the first and second onboard antennas 10 and 20 are changed based on the calculated elevation angle and the calculation azimuth angle, so that the following advantages occur.

That is, it is not necessary to connect the onboard antennas 10 and 20 to a navigation device such as a gyroconbus as in the conventional case.
It is sufficient to provide a drive control device for the onboard antenna near the second onboard antennas 10 and 20. Therefore, the outfitting work can be minimized, and the cost and the construction period can be shortened.

Further, even if the elevation angle and the azimuth angle are not indirectly obtained from the information obtained from the navigation device such as the gyrocompass as in the conventional case, the elevation angle and the azimuth angle can be obtained by directly measuring the distance to the communication satellite A. it can. Therefore, it is possible to orient the onboard antenna with respect to the communication satellite with high accuracy without being affected by the performance of other devices and even when the communication satellite is perturbed.

Further, satellite communication can be performed even when the navigation device is out of order. Therefore, even if the navigation device fails, it is possible to cause the ship station 1 to travel along a predetermined route by using the result of satellite communication.

In this embodiment, the ship station 1 is provided with the first and second onboard antennas 10 and 20, but three or more may be provided as long as two or more onboard antennas are used.

Further, in the present embodiment, the elevation angle and the azimuth angle are calculated based on the equations (1) to (3), but if desired accuracy is obtained, the approximate angle is used for the calculation. May be.

(Effect of the Invention) As described above, if the onboard antenna drive control device of the present invention is used, the outfitting work can be reduced, and the cost and the construction period can be shortened. Furthermore, if the onboard antenna drive control device of the present invention is used,
The onboard antenna can be directed to the satellite with high accuracy.

[Brief description of drawings]

FIG. 1 is a system diagram of an onboard antenna drive controller of one embodiment of the present invention, FIG. 2 (a) is a side view of a ship station in which the onboard antenna drive controller of FIG. 1 is installed, and FIG. 2B is a plan view of the ship station of FIG. 2A, FIG. 3 is a view for explaining the principle of obtaining the elevation angle of the onboard antenna in the onboard antenna drive control device of FIG. 1, and FIG. 4 is of FIG. It is a figure explaining the principle which calculates | requires the azimuth of an onboard antenna in an onboard antenna drive control device. 1 ... Ship station, 10 ... First shipboard antenna, 11 ... First transmitter, 12 ... First receiver, 13 ... First detector, 14 ... First driver , 20 ... second on-board antenna, 21 ... second transmitter, 22 ... second receiver, 23 ... second detector, 24 ... second driver, 30 ... sign Generator, 31 …… Sign bit difference measuring device, 32 …… Controller.

Claims (1)

[Claims] 1. A plurality of onboard antennas provided at predetermined intervals in the longitudinal direction of a ship station for satellite communication, and an electromagnetic wave transmitted from each of the onboard antennas to the satellite to generate a reflected wave from the satellite. Distance measuring means for receiving the respective onboard antennas to measure the distances between the respective onboard antennas and the satellites, and elevation angles at which the onboard antennas accurately point to the satellites based on the distances measured by the distance measuring means. And calculating means for calculating the azimuth angle, and driving means for driving the elevation angle and the azimuth angle of each of the onboard antennas based on the calculated elevation angle and the calculated azimuth angle by the calculating means to direct each of the onboard antennas to the satellite. An onboard antenna drive control device for a ship station for satellite communication.