JPH08149062A - Satellite ground station - Google Patents

Abstract

(57) [Summary] [Purpose] In an artificial satellite ground station, even when multiple satellites enter the observation range at the same time, it is possible to receive and transmit data with all satellites, and to expand the observation range. . [Configuration] A plurality of satellites 10-1, 10-2, 11-1,
A plurality of antennas 2a, 2b for receiving the radio waves 11-2
And a distributor 3a, 3b for distributing the output of the antenna, and a switch 4a for selecting and outputting one of the outputs of the plurality of distributors.
-1, 4a-2, 4b-1, 4b-2 and a receiving device 5 for performing a dedicated receiving process corresponding to the satellite by the output of the switching device
a-1, 5a-2, 5b-1, 5b-2. When the satellite 2-2 enters the observation range while the antenna 2a is tracking the satellite 10-1, the antenna 2b is caused to track the satellite 10-2, and at the same time, its output is input to the dedicated receiving device 5a-2. In addition, the antennas 2a and 2b are operated by the operation of the switching device.
The observation range of is synthesized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial earth ground station for communicating with an artificial satellite.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional artificial satellite ground for receiving radio waves transmitted by an artificial satellite, for example, an earth observation satellite for the purpose of investigating the earth environment and resources. The configuration of the station is shown.

In the figure, 1 is an artificial satellite ground station, which is an earth observation satellite (hereinafter referred to as "satellite") 10-1,
Antennas 2 for receiving radio waves from 10-2, ... And receivers 5-1 and 5 for performing reception processing based on the outputs thereof.
-2, ... Here, the plurality of receiving devices 5-1 and 5-2 are provided in order that the artificial satellite ground station 1 receives and processes radio waves for each of the plurality of satellites 10-1, 10-2 ,. is there. That is, the time period during which the artificial satellite ground station 1 can receive the radio waves from this type of satellite is as short as about 15 to 20 minutes, and if only one satellite is the receiving target, the operation efficiency becomes poor. Therefore, artificial satellite ground station 1
Are usually designed to capture and process the radio waves transmitted by multiple satellites over the sky. However, since these satellites have different specifications one by one, a dedicated receiving device is required for each receiving process. For this reason,
A dedicated receiver is required for each satellite to be received.

Therefore, the receiving device 5-1 of FIG.
The receiving device 5 receives data exclusively from the satellite 10-1.
2 exclusively receives data from the satellite 10-2. As illustrated, the satellites 10-1 and 10-2 include antennas 10a-1 and 10a-2 for transmitting data, respectively.

Next, the operation will be described. Satellite 10-
Numerals 1 and 10-2 are satellites for investigating the global environment and resources, and both observe the atmosphere and the surface of the earth while moving in orbit of the earth. Therefore, unlike the case of a geostationary satellite, the satellites 10-1 and 10-2 do not stop at one place when viewed from the ground, but pass over the sky in order. At this time, satellite 10-
It is assumed that 1 and 10-2 do not pass over the sky at the same time but move at a constant interval.

First, the antenna 2 of the artificial satellite ground station 1
By changing its direction, the first passing satellite 10-1 is tracked and the radio wave transmitted from the antenna 10a-1 of the satellite 10-1 is received. Next, after the satellite 10-1 passes, the antenna 2 of the artificial satellite ground station 1 tracks the satellite 10-2 and receives the radio wave transmitted from the antenna 10a-2 of the satellite 10-2. In this way, the antenna 2 tracks the entire sky while following the orbits of the satellites 10-1 and 10-2 as seen from the ground. The elevation angle (EL) of the antenna at this time is generally 5 ° or more.

Satellite 10-1 received by antenna 2
The signal of is subjected to reception processing by the dedicated receiving device 5-1.
Similarly, the signal of the satellite 10-2 is received by the dedicated receiving device 5-2.

[0008]

The conventional artificial earth ground station has the following problems. The first problem is that it could not be dealt with when multiple satellites simultaneously entered the observation range. The second problem is that if the observation range is limited by obstacles around the antenna, the necessary data cannot be received. Hereinafter, the first problem and the second problem will be described.

First, the first problem will be described. The observation range of the artificial satellite ground station 1 is the range indicated by RANGE in FIG. 12, and the satellites 10-1 and 10-2 in the RANGE are PATH10-1 and PTH, respectively.
Consider the case of traveling through the route of ATH10-2.
Here, PATH10-1 and PATH10-2 indicate the loci of the points directly below the satellites 10-1 and 10-2, respectively.
When TH10-1 and PATH10-2 are in RANGE, the antenna 2 and the satellites 10-1 and 10-2 can be seen and the transmitted radio waves can be received. Note that how the observation range is determined will be described later.

At this time, as shown in FIG. 13A, after the satellite 10-1 goes out of RANGE, the satellite 10-2 goes to R.
To enter ANGE, set antenna 2 to satellite 10-1,
It suffices to direct and track in the order of 10-2, and both radio waves can be received. On the other hand, as shown in (b) of the figure, during the T time from time t _{1 to} t ₂ , the satellite 10-
When 1 and satellite 10-2 are in RANGE at the same time, they cannot be tracked at the same time. As shown in FIG. 12, because the position of the satellites 10-1 and 10-2 are different at time t ₁ (or the time t _2).

Next, the second problem will be described. To receive the radio waves from the satellites 10-1 and 10-2,
The antennas 2 must be able to see the satellites 10-1 and 10-2. By the way, since radio waves cannot be received if there is an obstacle to the radio waves and the line of sight cannot be seen, the height of the obstacle to the radio waves existing around the antenna 2 becomes a problem in determining the range of observation. Here, the outline of the upper end of the obstacle viewed from the antenna 2 is called the skyline. This skyline is generally represented by an elevation angle (EL angle) with respect to an azimuth angle (AZ angle: 0 ° to 360 °) about the entire circumference of the antenna 2. FIG. 14 shows an example of the skyline. Further, FIG. 15 shows an explanatory view of the EL angle.

Further, for the same skyline, the higher the satellite altitude, the wider the observation range. That is, in FIG.
As shown in, when the skylines (in this case, "mountains") have different influences depending on the altitudes h ₁ and h ₂ of the satellites, and in the case of satellite orbits (PATH) with the same latitude and longitude, when the altitude is high (h ₂ ). Can secure the line of sight, but if the altitude is low (h ₁ ), it will be overshadowed by the shadow of “mountain”.

Therefore, the actual RANGE is determined by the skyline and the altitude of the satellite. This will be described with reference to FIG. In the figure, RANGEa is the observation range when the satellite altitude is h ₁ , and RANGEa is
b is the observation range when the satellite altitude is h ₂ when the skylines are the same. RANGEa, RAN
All GEb are affected by obstacles around the antenna 2, and the observation range is narrower than in the case where there are no obstacles (if there are no obstacles, RAN is RAN).
Both GEa and RANGEb are circular). In addition, RANGEb is more likely to correspond to RANGEa depending on the satellite altitude.
Wider than.

In this case, the satellite 10-1 is the PAT.
When moving on H10-1, if highly h _1, narrow observation area than in the altitude h _2, the time to receive data is shortened. In addition, satellite 10-2 is PATH10.
-2, it is outside the range of RANGEa because PATH10-2 passes through the eastern end of the observation range. Therefore, if the satellite's altitude is h ₂ , data can be received, but if the satellite's altitude is h _{1 and} it is h ₁ , data cannot be received. As described above, when the observation range is limited by the skyline of the antenna, the limitation is added when receiving the data as compared with the case where there is no obstacle.

In the above description, the case of receiving a radio wave from a satellite has been taken as an example, but the same problem occurs when transmitting a control signal, a communication signal, etc. to a satellite, and the same problem occurs.

The present invention has been made to solve the above problems, and the first object of the present invention is to make it possible to cope with a case where a plurality of satellites simultaneously enter the observation range. Is to provide the station. A second object is to provide a satellite ground station that can reduce the influence of antenna skyline on data reception and transmission.

[0017]

According to a first aspect of the present invention, there is provided an artificial earth ground station comprising: a plurality of receiving antennas for receiving radio waves emitted by a plurality of satellites; and an output signal from the plurality of receiving antennas. A switching device that selects and outputs one output signal, and a reception processing device that performs reception processing based on the output of the switching device are provided.

An artificial satellite ground station according to a second aspect selects a plurality of receiving antennas for receiving radio waves emitted by a plurality of satellites and one of the output signals from the plurality of receiving antennas. And a reception processing device that performs reception processing based on the output of the switching device, and one reception antenna is specified from the plurality of reception antennas, and an output signal of the specified reception antenna is selected. And a management device for controlling the switching device.

An artificial satellite ground station according to a third aspect of the present invention is configured such that the management device specifies one observable receiving antenna based on a predetermined observation time table of the plurality of satellites.

An artificial satellite ground station according to a fourth aspect of the present invention can observe the management device based on predetermined orbit information of the plurality of satellites and predetermined observation ranges of the plurality of receiving antennas. The configuration is such that one receiving antenna is specified.

An artificial satellite ground station according to a fifth aspect distributes an output signal from the receiving antenna into a plurality of signals, and
It is provided with a distributor that outputs one of the distributed output signals to the switch.

In the artificial earth ground station according to a sixth aspect of the present invention, the switching device receives the analog signal output from the receiving antenna and outputs the selected analog signal to the reception processing device. It is what

In the artificial earth station according to a seventh aspect of the present invention, a digital signal converted from an analog signal output from the receiving antenna is input to the switch, and the selected digital signal is received by the reception processing device. It is configured to output to.

An artificial satellite ground station according to claim 8 is any one of a plurality of transmission antennas for transmitting radio waves to the satellite, a transmission processing device for generating a signal to be transmitted to the satellite, and the plurality of transmission antennas. And a switching device that selects one transmission antenna and outputs the signal generated by the transmission processing device to the selected transmission antenna.

An artificial satellite ground station according to a ninth aspect includes any one of a plurality of transmitting antennas for transmitting radio waves to the satellite, a transmission processing device for generating a signal to be transmitted to the satellite, and the plurality of transmitting antennas. One transmitting antenna is selected, a switch that outputs a signal generated by the transmission processing device to the selected transmitting antenna, and one transmitting antenna is specified from the plurality of transmitting antennas, and the specified transmitting antenna is selected. And a management device for controlling the switching device.

An artificial satellite ground station according to a tenth aspect of the present invention is configured such that the management device specifies one transmitting antenna that can transmit based on a predetermined observation time table of the satellite.

An artificial satellite ground station according to claim 11 is capable of observing the management device based on a predetermined orbit information of the satellite and a predetermined observation range of each of the plurality of transmitting antennas. The configuration is such that the transmission antenna is specified.

An artificial satellite ground station according to a twelfth aspect of the present invention is configured such that the switching device receives an analog signal output from the transmission processing device and outputs an analog signal to a selected transmission antenna. It was done.

An artificial satellite ground station according to a thirteenth aspect of the present invention is configured such that the switching device receives the digital signal output from the transmission processing device and outputs the digital signal to a selected transmission antenna. It was done.

[0030]

According to the invention of claim 1, the plurality of receiving antennas receive the radio waves emitted from the plurality of satellites, and the switch selects one of the output signals from the plurality of receiving antennas. Then, the reception processing device performs reception processing based on the output of the switch.

According to the second aspect of the invention, the plurality of receiving antennas receive the radio waves emitted by the plurality of satellites, and the switching device selects one of the output signals from the plurality of receiving antennas. The reception processing device performs reception processing based on the output of the switching device, and the management device specifies one reception antenna from the plurality of reception antennas and selects the output signal of the specified reception antenna. To control the switching device.

In the invention of claim 3, the management device identifies one observable receiving antenna based on a predetermined observation time table of the plurality of satellites.

According to a fourth aspect of the present invention, the management device can perform one observable reception based on predetermined orbit information of the plurality of satellites and predetermined observation ranges of the plurality of receiving antennas. Identify the antenna.

In the fifth aspect of the invention, the distributor distributes the output signal from the receiving antenna into a plurality of signals, and outputs one of the distributed output signals to the switching device.

According to the sixth aspect of the invention, the switching device switches the analog signal.

In the invention of claim 7, the switching device switches the digital signal.

According to the invention of claim 8, the plurality of transmitting antennas transmits radio waves to the satellite, the transmission processing device generates a signal to be transmitted to the satellite, and the switching device selects one of the plurality of transmitting antennas. One transmission antenna is selected, and the signal generated by the transmission processing device is output to the selected transmission antenna.

In the ninth aspect of the present invention, the plurality of transmission antennas transmit radio waves to the satellite, the transmission processing device generates a signal to be transmitted to the satellite, and the switching device selects one of the plurality of transmission antennas. One transmission antenna is selected, the signal generated by the transmission processing device is output to the selected transmission antenna, and the management device outputs one signal from the plurality of transmission antennas.
The two switching antennas are specified, and the switch is controlled so as to select the specified transmitting antenna.

In the tenth aspect of the present invention, the management device specifies one transmit antenna that can be transmitted based on a predetermined observation time table of the satellite.

In the eleventh aspect of the present invention, the management device selects one transmitting antenna that can be observed based on the predetermined orbit information of the satellite and the predetermined observation range of each of the plurality of transmitting antennas. Identify.

In the twelfth aspect of the present invention, the switching device switches analog signals.

In the thirteenth aspect of the invention, the switching device switches the digital signal.

[0043]

【Example】

Example 1. FIG. 1 shows the configuration of an artificial satellite ground station which is an embodiment of the present invention. This figure shows a case where the artificial satellite ground stations 1a and 1b installed at two locations receive data from the satellites 10 and 11. The artificial satellite ground stations 1a and 1b may be installed, for example, several hundred meters apart.

In the figure, 1a and 1b are artificial satellite ground stations, which are installed apart from each other. The artificial satellite ground stations 1a and 1b are earth observation satellites (hereinafter referred to as "satellite") 10-1, 10-2, ... And 11-1, 11-.
Antennas 2a and 2b for receiving radio waves from 2, ...
And a distributor 3a, 3b for distributing the outputs of the antennas 2a, 2b into two outputs, respectively, and a switch 4a-for receiving and outputting the output of the distributor 3a and the output of the distributor 3b. 1, 4a-2, ... and 4b-1, 4
b-2, ... and switching devices 4a-1, 4a-1 ,.
And receiving devices 5a-1, 5a-2, ... And 5b-1, 5 which receive the outputs of 4b-1 and 4b-2 and perform receiving processing.
b-2, ... Receiving device 5a-1,
5a-2, 5b-1, and 5b-2 are satellites 10-, respectively.
It is for receiving the radio waves from 1, 10-2, 11-1, 11-2 exclusively. It should be noted that the distributors 3a and 3b distribute analog signals, and the switching devices 4a-1 and 4a-
2, ..., 4b-1, 4b-2, ... Switch analog signals.

Here, the plurality of receiving devices are provided in the artificial satellite ground stations 1a and 1b and the plurality of satellites 10-1 and 10-.
This is for receiving and processing radio waves from 2, ... And 11-1, 11-2 ,. That is, since the artificial satellite ground stations 1a and 1b can receive the radio waves from this type of satellite in a short time of about 15 to 20 minutes, the operation efficiency of only one satellite is deteriorated. Therefore,
The artificial satellite ground stations 1a and 1b are usually formed so as to capture and process radio waves transmitted by a plurality of satellites passing over the sky. However, since these satellites have different specifications, the receiving process requires a dedicated receiving device. Therefore, a dedicated receiver is required for each satellite to be received.

The satellites 10-1, 10-2, ...
Radio waves from 11-1, 11-2, ... Can be received by either of the antennas 2a and 2b as long as the satellite is within the observation range. The signals received by the antennas 2a and 2b are distributed by the distributors 3a and 3b and supplied to both the artificial satellite ground stations 1a and 1b. Therefore, the receiving devices 5a-1, 5a-2, ..., 5b-1,
5b-2, ... Can perform reception processing based on the output of either antenna 2a or 2b.

Further, in the figure, 10-1, 10-
2, 11-1, 11-2 are earth observation satellites, and antennas 10a-1, 10a-2, 1 for transmitting data are provided.
1a-1 and 11a-2 are provided, respectively.

FIG. 2 is a diagram in which the observation ranges corresponding to the skylines of the antennas 2a and 2b are displayed simultaneously. In the figure, RANGE A is an observation range based on the skyline of the antenna 2a, RANGE B
Indicates the observation range based on the skyline of the antenna 2b (all are roughly about a radius of about 2000 km). It is assumed that the satellites 10 and 11 have the same altitude at this time.

PATHs 10-1 and 10-2 in the figure are loci of the points directly below the satellites 10-1 and 10-2 in a certain time zone, and PATH 11-1 is a satellite 11-in a certain time zone.
The locus of the point immediately below 1 is shown. Since many Earth observation satellites have sun-synchronous trajectories, they follow a trajectory that moves from south to north or from north to south, as shown in the figure. PATH10-1 is RAN
Pass through almost the center of GE A and RANGE B, PAT
H10-2 passes slightly east of PATH10-1, and PA
TH11-1 passes almost the west end of RANGE B (R
Outside the range of ANGE A).

FIG. 2 shows an example in which the antennas 2a and 2b are installed in almost the center of Japan (for example, in the suburbs of Tokyo). In the case of the antenna 2a, it is about southwest due to its unique skyline. The observation range is limited from the direction to the northwest, and the observable distance becomes shorter. In the case of the antenna 2b, for the same reason, the observable range is limited from the northwest direction to the northeast direction, and the observable distance is short. However, as shown in FIG. 2, considering the observation range in which the observation ranges RANGE A and RANGE B by the antennas 2a and 2b are combined, a predetermined observation range is obtained in almost all directions except a part in the northwest direction. Is secured.

FIG. 2 is a diagram in which the observation ranges of the antennas 2a and 2b are combined, and FIG. 3A shows the observation range of the antenna 2a alone. Further, FIG. 2B is a skyline of the antenna 2a in which the azimuth angle (AZ angle) is taken in the clockwise direction with the true north as 0 degree. According to the figure, about 23
There is an obstacle from 0 degree to about 330 degrees, and it is necessary to make the elevation angle (EL angle) of the antenna larger in this azimuth angle than in other azimuth angles in order to see.

Similarly, FIG. 4A shows the observation range of the antenna 2b alone. Further, FIG. 2B shows the antenna 2b.
It is the skyline of, and there are obstacles from about 330 degrees to about 30 degrees.

Next, the operation will be described with reference to FIGS. Since the earth observation satellite is a satellite for investigating the global environment and resources, the satellites 10-1, 10-2, 1
Each of 1-1 and 11-2 observes the atmosphere and the ground surface while moving in an orbit around the earth. Therefore, unlike the case of the geostationary satellite, since the earth observation satellite is not stationary at one place as seen from the ground, the antennas 2a and 2b of the artificial satellite ground stations 1a and 1b are the satellites 10-1, 10-2 and 11 respectively. −
With the movement of 1 and 11-2, the antennas 2a and 2b are directed so as to track them, and the directions are moved. That is, the antennas 2a and 2b are the satellites 10- seen from the ground.
The whole sky is tracked along the orbits of 1, 10-2, 11-1, 11-2. At this time, the antennas 2a and 2b change within a range of angles above the horizon. The elevation angle (EL) of the antenna is generally 5 ° or more.

Next, how to control the switching unit in response to the movement of the satellite will be described. First, in order to be able to deal with a case where a plurality of satellites enter the observation range at the same time, the following control is performed.

The observation range of the artificial satellite ground station 1 is the range indicated by RANGE A and RANGE B in FIG. 2, and the satellites 10-1 and 10-2 in the RANGE A and RANGE B respectively have PATH10-.
Consider the case of moving through the route of 1, PATH 10-2. Here, when PATH 10-1 and PATH 10-2 are in RANGE A, the antenna 2a and the satellite 10 are
The transmitted radio waves can be received with the line of sight of -1, 10-2. The same applies to the case of RANGE B.

At this time, as shown in FIG. 13 (a), the satellite 10-1 goes out of the RANGE A and then the satellite 10-2.
When entering the RANGE A, the antenna 2a may be directed in the order of the satellites 10-1 and 10-2 and tracked,
Both radio waves can be received. Therefore, the switch 4a-
Both 1 and 4a-2 may be controlled so as to select the output of the antenna 2a.

On the other hand, as shown in FIG.
When the satellite 10-1 and the satellite 10-2 are simultaneously in RANGE A during the time T from time t _{1 to} t ₂ ,
The antenna 2a cannot track these at the same time. Therefore, the operator sets the switch 4a-1 to the antenna 2a.
Control is performed so that the output of the satellite 10-2 is selected, and at the time t ₁ and the observation time zone of the satellite 10-2, the switching unit 4
a-2 is controlled to select the output of the antenna 2b. At the same time, the antenna 2b is controlled so as to track the satellite 10-2. By doing this, the antenna 2
a and 2b are able to track the satellites 10-1 and 10-2, respectively, and at the same time, the satellites 10-1 and 10-2 are in the observation time zone.
It is possible to simultaneously receive and process the radio waves of.

As described above, within the observation range that can be covered by both the antennas 2a and 2b, even if two satellites come in at the same time, it can be dealt with and data reception will not be disabled. If the third satellite 11-1 or 11-2 is in the observation range, the antenna 2b cannot be used for tracking the satellite 10-2, but it is rare that many satellites are in the observation range at the same time. , Practically not a problem.

Next, control for reducing the influence of obstacles around the antenna on data reception will be described.

It is assumed that the orbit of the satellite to be received has been obtained in advance. Then, it is assumed that the observation ranges of the antennas 2a and 2b are as shown in FIG. According to FIG. 2, PAT
For H10-1 and 10-2, data can be received for a longer time when it is received by the antenna 2a, and for PATH11-1, data cannot be received unless the antenna 2b is used. Therefore, when the operator receives the radio waves from the satellites 10-1 and 10-2, the operator receives the receiving device 5a based on the signal received by the antenna 2a.
-1, 5a-2, so that the switching processing 4a-
1, 4a-2 causes the signal of the antenna 2a to be selected. When receiving the radio wave from the satellite 11-1, the switch 4b-1 is caused to select the signal of the antenna 2b so that the receiving device 5b-1 can perform the receiving process based on the signal received by the antenna 2b.

As described above, in the first embodiment, the operator selects the optimum combination of the antenna and the satellite (reception device) based on the relationship shown in FIG. 2, and manually switches the switch 4a.
-1, 4a-2, 4b-1, 4b-2 are controlled.

Next, the method of obtaining the values shown in FIGS. 2 and 3 will be described. These maps are obtained from the antenna-specific skyline and satellite orbit information. Here, since the orbits of the satellites to be received are obtained in advance, the satellites 10-1 and 10
For each of −2, 11-1, and 11-2, the latitude, longitude, and altitude at any time can be known. The trajectory PATH10-1 of the satellite is obtained by plotting the above latitude and longitude on a map.

The observation range is shown in FIG. 3 (b) and FIG.
As shown in (b), azimuth angle (AZ angle), elevation angle (EL
The angle is calculated from the skyline and the altitude of the satellite. Here, it is necessary to determine the altitude of the satellite and convert the skyline under this condition from the expression by the parameters of AZ and EL to the expression by the latitude and longitude on the earth. Because the satellite 10-1,
This is because the orbits 10-2, 11-1, and 11-2 are represented by latitude and longitude on the earth, and therefore it is necessary to unify the parameters for comparison. The observation range is plotted on the map based on the converted latitude and longitude information.

As described above, according to the first embodiment, the plurality of antennas 2a and 2b, the dividers 3a and 3b for dividing the outputs of the antennas 2a and 2b into two, and the antenna 2 are provided.
Switching devices 4a-1 and 4 for selecting and outputting the outputs of a and 2b
Since a-2, 4b-1, and 4b-2 are provided, even when a plurality of satellites simultaneously enter the observation range, they can be tracked by a plurality of antennas and receive data for each satellite. Even when the observation range is narrowed by the obstacles around the antenna, the observation range can be expanded by combining the observation ranges of the plurality of antennas, and the influence of the obstacle on the data reception can be reduced.

Further, according to the first embodiment, even when the operation of one antenna is stopped due to maintenance and inspection,
Data can be received by the other antenna,
It can also reduce the downtime of operations. Furthermore, since the distributor receives the received signal of the antenna and supplies it to a plurality of artificial satellite ground stations, the received signal of one antenna can be received and processed by the other artificial satellite ground station. And the antenna can be operated efficiently.

In the first embodiment, the case where the number of antennas is two has been described as an example, but the present invention is not limited to this, and the number of antennas may be three or more. In this case, the switching device has three or more inputs corresponding to the number of antennas. Further, similarly, the present invention can be applied even when the number of receiving devices is three or more.

Further, in FIG. 1, the receiving devices 5b-1,
There is no 5b-2, and either of the antennas 2a and 2b may be for tracking the satellites 10-1 and 10-2, and the same effect is obtained.

Example 2. In the case of the above-described first embodiment, the operator manually switches the switch, but the management device that predicts the observation time of the satellite based on the orbit information of the plurality of satellites selects the satellite and automatically tracks the antenna. Alternatively, the switching device may be controlled together.

FIG. 5 is a block diagram of an artificial satellite ground station according to the second embodiment. In FIG. 5, reference numeral 6 predicts the observation time of the satellite from the observation time table created based on the orbit information of a plurality of satellites. , When the satellite enters the observation range, the optimum one is selected from the antennas 2a and 2b to be tracked, and the switching devices 4a and 4b are switched to supply the reception signal to the receiving device corresponding to the satellite. It is a management device that does.

The artificial satellite ground stations 1a and 1b, the antennas 2a and 2b, the distributors 3a and 3b, and the switches 4a-1 and 4a.
a-2, 4b-1, 4b-2, receiving devices 5a-1, 5a
-2, 5b-1, 5b-2, satellites 10-1, 10-2,
11-1, 11-2, satellite antennas 10a-1, 10
a-2, 11a-1, 11a-2 are the same as those shown in FIG.

Next, the operation will be described based on the flowchart of FIG. 6 showing the operation of the management apparatus 6. First, the management device 6 performs an observation time table (a time chart, for example, as shown in FIG. 13) for the observation time zone of the satellite to be observed based on the orbit information of the satellite given beforehand and the observation range by the skyline peculiar to the antenna. ) Is created.
Then, this time chart is compared with the current time to determine whether the observation time of a new satellite X (satellite 10-1, ...) Has arrived. When it is determined that the observation time has come, the process proceeds to the next step ST2 (ST
1).

At ST2, the trajectory of the satellite X (corresponding to PATH10-1 in FIG. 2) is obtained from the satellite orbit information, and the process proceeds to the next step ST3.

In ST3, the trajectory of the satellite X and the observation range of the antenna 2a are compared with each other by referring to the diagram shown in FIG. 2, for example, and it is determined whether or not the satellite X can be observed by the antenna 2a. If both antennas 2a and 2b can be observed, it is determined whether more effective observation can be performed (for example, long-term observation is possible) (this point also applies to ST4 described later). If it can be observed, the process proceeds to step ST11. If it cannot be observed, the process proceeds to step ST4.

At ST11, it is determined whether the antenna 2a is in use. If it is being used for tracking another satellite, or if it is unavailable due to a failure or the like, the process proceeds to step ST4. If it can be used, the process proceeds to step ST12.

In ST12, the management device 6 instructs the antenna 2a to track the satellite X. Then, the management device 6 uses the switching device X (4a-1 in FIG. 5, ...
Antenna) to the receiving device X (any one of 5a-1 in FIG. 5) for receiving the satellite X.
A switching command is issued so that the reception signal of a is input (ST13). By such control, the data from the satellite X can be received by the dedicated receiving device X (ST
14).

On the other hand, in the case of proceeding from ST11 to ST4, in ST4, satellite X is transmitted in the same manner as in ST3.
And the observation range of the antenna 2b are compared to determine whether the satellite X can be observed by the antenna 2b. If it can be observed, the process proceeds to step ST21. Step ST21-
The processing in 24 is similar to that in steps ST11 to ST14, and therefore the description thereof is omitted. If it cannot be observed, the process proceeds to step ST5.

When the process proceeds to step ST5, the antenna of the satellite X is outside the observation range of both antennas 2a and 2b, or an antenna that can be observed even if it is within the observation range is used for tracking other satellites. Or, it is unusable for satellite X due to failure or maintenance,
It is when the data from satellite X cannot be received. Therefore, in step ST5, the fact that data cannot be received is reported to the operator or the like.

As described above, according to the second embodiment, the satellite observation time is predicted based on the orbit information of a plurality of satellites,
Antennas 2a and 2b when satellites enter the observation range
This is tracked by one of the
Since it has a management device that switches 4b and supplies the reception signal to the receiving device corresponding to the satellite, it can be tracked by multiple antennas even when multiple satellites are in the observation range at the same time. Can be received, and even if the observation range is narrowed by obstacles around the antenna, the observation range can be expanded by combining the observation ranges of multiple antennas, and The impact can be reduced, and further,
The above-described control of the antenna and the switching device can be automatically performed, and the work load on the operator can be reduced.

Further, according to the second embodiment, even when the operation of one antenna is stopped due to maintenance and inspection,
Data can be received by the other antenna,
It can also reduce the downtime of operations.

In the second embodiment, the processing based on the observation time table of the satellite (ST1) and the processing based on comparison between the satellite orbit information and the observation range of the antenna (ST3, ST4).
Although both of the above processes are performed, either one of the processes may be performed. Even in this case, either one of the first problem and the second problem can be solved.

In the second embodiment, the case where the number of antennas is two has been described as an example, but the number of antennas is not limited to this and may be three or more.

Further, in FIG. 6, the receiving devices 5b-1,
There is no 5b-2, and either of the antennas 2a and 2b may be for tracking the satellites 10-1 and 10-2, and the same effect is obtained.

Example 3. In the artificial satellite ground stations 1a and 1b of the first embodiment, the outputs of the antennas 2a and 2b are distributed to receive devices 5a-1, 5a-2, 5b-1, 5b-.
However, the present invention is not limited to this and may be distributed by the output of the receiving device as shown in FIG.

In the figure, 7a-1, 7a-2, 7b
-1, 7b-2 are satellites 10-1, 10-, respectively.
It is a recording facility that receives data received from 2, 11-1 and 11-2 and performs recording on a tape or the like based on the frame synchronization unique to the satellite and the data format. Also,
Distributors 3c and 3d in the same figure are different from distributors 3a and 3b that distribute the analog signal before the reception process output from the antenna of FIG. 1 in that the digital signals that have undergone the reception process are distributed. At the same point, the switches 4c-1, 4c-2, 4d-
1, 4d-2 are switching devices 4a-1, 4a-2, 4 of FIG.
Different from b-1 and 4b-2. In addition, the receiving device 5 of FIG.
c and 5d are satellites 10-as well as the antennas 2a and 2b.
1, 10-2, 11-1, 11-2 can be processed corresponding to all, and in this respect, the receiving device 5 dedicated to a specific satellite of FIG.
Different from a and 5b.

Next, the operation will be described. This Example 3
The operations of the artificial satellite ground stations 1a and 1b are the same as those in the first embodiment, and the distributors 5c and 5d and the switch 4 are structurally different.
c-1, 4c-2, 4d-1, 4d-2 are receivers 5
Recording equipment 7a-1, 7a-, which is closer to the terminal than c and 5d
Only the points on the 2, 7b-1 and 7b-2 side are different.

That is, the antennas 2a, 2b of the artificial satellite ground stations 1a, 1b are the satellites 10-1, 10-2, 11-.
These are tracked with the movement of 1 and 11-2. The received signals are subjected to receiving processing in the receiving devices 5c and 5d, converted into digital signals, and then divided into two by the distributors 3c and 3d. Switchers 4c-1, 4c-2, 4d-
1, 4d-2 selects either one of the digital outputs of the distributors 3c, 3d, and the recording equipments 7a-1, 7a are respectively selected.
Output to -2, 7b-1 and 7b-2. The recording facility records data in a predetermined format unique to the satellite. The control of the antennas 2a and 2b and the switching device 4c-
The control of 1, 4c-2, 4d-1, and 4d-2 is the same as in the case of the first embodiment, so the description thereof will be omitted.

As described above, the signal may be distributed and selected at the stage after the reception processing. Note that the present invention is not limited to this, and a part that can be shared by devices having general-purpose functions capable of supporting all satellites (in the case of FIG. 7, the antenna 2
a, 2b and receiving devices 5c, 5d), the signal may be distributed at any stage as long as it is a stage after the common part.

According to the third embodiment, the same effect as that of the first embodiment is obtained, and compared with the case where the output of the antenna, which is a high frequency signal, is distributed, it can be transmitted by a digital signal. Be advantageous This is
When the distances between the antennas of a plurality of artificial satellite ground stations are large, it is very advantageous in terms of improving the performance and reliability of the equipment and reducing the cost. Even in the case of transmitting an analog signal in the intermediate frequency band and the baseband band with less loss, the same effect as in transmission is obtained as compared with the case of transmitting in a high frequency, and A / D conversion and D / A conversion are performed.
No conversion is required and the configuration is simple.

Example 4. In addition, the above-mentioned Examples 1 to 3
In the above, the case of receiving a signal from a satellite has been described as an example, but the present invention is not limited to this, and can be applied to the case of transmitting a control signal, a communication signal, or the like to a satellite, and the same effect is obtained. Examples of the configuration of the artificial satellite ground station according to the fourth embodiment are shown in FIGS. 8, 9 and 10.

FIG. 8 is a diagram showing the structure of an artificial satellite ground station to which the structure of the first embodiment is applied in the case of transmission. In FIG. 8, 8a and 8b are the transmission signals from the artificial satellite ground station 1a and the artificial signal. Synthesizers 9a-1 and 9a for synthesizing a transmission signal from the satellite ground station 1b and outputting the synthesized signal to the antennas 2a and 2b.
a-2, 9b-1, 9b-2 are artificial satellites 10-1, 1
The transmitting device generates and outputs transmission signals such as control signals and communication signals corresponding to 0-2, 11-1, and 11-2.

Further, the antennas 2a and 2b and the switch 4e-
1, 4e-2, 4f-1 and 4f-2 are the same as or equivalent to those described in the first to third embodiments.
Further, the operation is the same as that of the first embodiment except that the signal flow is reversed in accordance with the change of the receiving process to the transmitting process, and thus the description thereof will be omitted.

FIG. 9 is a diagram showing the structure of an artificial satellite ground station to which the structure of the second embodiment is applied in the case of transmission. Since each component in the figure is the same as that in the case of FIG. 8, description thereof will be omitted. The operation is also the same as that of the second embodiment except that the signal flow is reversed in accordance with the change of the receiving process to the transmitting process, and thus the description thereof will be omitted.

FIG. 10 is a diagram showing the structure of an artificial satellite ground station to which the structure of the third embodiment is applied for transmission.
In the figure, 21a and 21b are the transmission data (digital signal) from the artificial satellite ground station 1a and the artificial satellite ground station 1b.
22a-, which is a data synthesizer for synthesizing the transmission data (digital signal) from the antenna and outputting the synthesized data to the antennas 2a and 2b.
1, 22a-2, 22b-1, 22b-2 generate transmission data such as control command data and communication data corresponding to the artificial satellites 10-1, 10-2, 11-1, 11-2, respectively. It is a control device that outputs.

Further, the antennas 2a and 2b and the switch 4e-
1, 4e-2, 4f-1 and 4f-2 are the same as those in FIG. Further, the operation is the same as that of the third embodiment except that the signal flow is reversed in accordance with the change of the receiving process to the transmitting process, and thus the description thereof will be omitted.

According to the structure of the fourth embodiment, it can be applied to the transmission to the satellite, and the same effects as those of the first to third embodiments can be obtained.

It is needless to say that the satellites in the above-mentioned first to fourth embodiments can be applied not only to the earth observation satellite but also to general satellites and have the same effect.

[0097]

As described above, according to the inventions of claim 1, claim 2, claim 8 and claim 9, a plurality of receiving antennas / transmitting antennas and the plurality of antennas are selected and switched. Since it is equipped with a device, it can receive and transmit data for each satellite when multiple satellites enter the observation range at the same time, and it also expands the observation range by combining the observation ranges of multiple antennas. It is possible to reduce the influence of obstacles on data reception / transmission.

According to the inventions of claims 3 and 10, a plurality of receiving antennas / transmitting antennas, a switch for selecting and switching the plurality of antennas, and a predetermined satellite observation time table are provided. Based on the management device that identifies the observable and transmittable antennas, it is possible to receive and transmit data for each satellite when multiple satellites enter the observation range at the same time.

According to the inventions of claims 4 and 11, a plurality of receiving antennas / transmitting antennas, a switch for selecting and switching the plurality of antennas, a predetermined satellite orbit information, and predetermined satellite orbit information Since it has a management device that identifies the observable / transmittable antennas based on the specified antenna observation range, the observation range can be expanded by synthesizing the observation ranges of multiple antennas to prevent obstacles to data reception / transmission. Can be reduced.

According to the invention of claim 5, a plurality of receiving antennas, a switch for selecting and switching the plurality of antennas, and an output signal from the receiving antennas are distributed to a plurality of and distributed. Since a divider for outputting one of the output signals to the switching device is provided,
The received signal of one antenna can be received and processed by another artificial satellite ground station, and the artificial satellite ground station and its antenna can be operated efficiently.

Further, according to the inventions of claims 6 and 12, a switching device for receiving the analog signal output from the transmission processing device and outputting the analog signal to the selected transmission antenna is provided. Since it is equipped, compared with the case of distributing and transmitting digital signals, A / D conversion, D /
The A conversion is unnecessary and the configuration is simple.

According to the sixth and eleventh aspects of the present invention, a switching device for receiving the digital signal output from the transmission processing device and outputting the digital signal to the selected transmission antenna is provided. Since it is provided, it is advantageous in terms of transmission in terms of reliability, as compared with the case where the analog signal is distributed and transmitted.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an artificial satellite ground station according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of the operation of the artificial satellite ground station according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an observation range and a skyline of the antenna 2a according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an observation range and a skyline of the antenna 2b according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram of an artificial satellite ground station according to a second embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation of the management device according to the second embodiment of the present invention.

FIG. 7 is a configuration diagram of an artificial satellite ground station according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram of an artificial satellite ground station according to a fourth embodiment of the present invention.

FIG. 9 is a configuration diagram of an artificial satellite ground station according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram of an artificial satellite ground station according to a fourth embodiment of the present invention.

FIG. 11 is a block diagram of a conventional artificial satellite ground station.

FIG. 12 is a diagram showing a conventional antenna observation range and a satellite trajectory.

FIG. 13 is an example of a satellite observation time table.

FIG. 14 is an example of an antenna skyline.

FIG. 15 is an explanatory diagram of an elevation angle (EL angle) of the antenna.

FIG. 16 is a diagram for explaining the operation of a conventional artificial satellite ground station.

FIG. 17 is a diagram for explaining the relationship between the observation range and the altitude of the satellite.

[Explanation of symbols]

1a, 1b satellite ground station, 2a, 2b antenna,
3a, 3b distributor, 4a, 4b switching device, 5a, 5b
Receiving device, 6 Management device, 7a, 7b Recording equipment, 8
a, 8b combiner, 9a, 9b transmitter, 10 satellites, 11 satellites, 21a, 21b data combiner, 22
a, 22b Control device.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tomohiro Fujiwara 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Communication Equipment Works (72) Inventor Fumiyoshi Murase 8-1-1 Tsukaguchihonmachi, Amagasaki (72) Inventor Yurika Hirano 8-1-1 Tsukaguchi Honmachi, Amagasaki City Mitsubishi Electric Corporation Communication Machine Works

Claims (13)

[Claims] 1. A plurality of receiving antennas for receiving radio waves emitted from a plurality of satellites, a switching device for selecting and outputting any one output signal from the plurality of receiving antennas, and the switching. An artificial earth ground station including a reception processing device that performs reception processing based on the output of a vessel. 2. A plurality of receiving antennas for receiving radio waves emitted from a plurality of satellites, a switcher for selecting and outputting any one output signal from the plurality of receiving antennas, and the switching. Processing device that performs reception processing based on the output of the switching device, and a management device that specifies one receiving antenna from the plurality of receiving antennas and controls the switching device to select the output signal of the specified receiving antenna Satellite ground station with and. 3. The management device is configured to specify one observable receiving antenna based on a predetermined observation time table of the plurality of satellites.
Artificial satellite ground station. 4. The management device specifies one observable receiving antenna based on predetermined orbit information of the plurality of satellites and a predetermined observation range of each of the plurality of receiving antennas. The artificial earth ground station according to claim 2, wherein 5. A divider which divides an output signal from the receiving antenna into a plurality of pieces and which outputs one of the divided output signals to the switcher. Item 5. An artificial satellite ground station according to any one of items 4. 6. The switching device receives an analog signal output from the receiving antenna and outputs a selected analog signal to the reception processing device. Item 5. The artificial satellite ground station according to any one of items 5. 7. The switching device receives a digital signal converted from an analog signal output from the receiving antenna and outputs the selected digital signal to the reception processing device. The artificial satellite ground station according to any one of claims 1 to 5. 8. A plurality of transmission antennas for transmitting radio waves to a satellite, a transmission processing device for generating a signal to be transmitted to the satellite, and one of the plurality of transmission antennas are selected and selected. An artificial earth ground station comprising: a switch that outputs a signal generated by the transmission processing device to a transmission antenna. 9. A plurality of transmission antennas for transmitting radio waves to a satellite, a transmission processing device for generating signals to be transmitted to the satellite, and one of the plurality of transmission antennas are selected and selected. A switching device that outputs a signal generated by the transmission processing device to a transmission antenna, and one transmission antenna is specified from the plurality of transmission antennas, and the switching device is controlled to select the specified transmission antenna. Artificial satellite ground station with management equipment. 10. The artificial satellite ground station according to claim 9, wherein the management device is configured to identify one transmitting antenna that can transmit based on a predetermined observation time table of the satellite. 11. The management device is configured to specify one observable transmission antenna based on predetermined orbit information of the satellite and a predetermined observation range of each of the plurality of transmission antennas. The artificial earth ground station according to claim 9. 12. The switching device receives the analog signal output from the transmission processing device and outputs the analog signal to a selected transmission antenna. 11. The artificial earth ground station according to any one of 11. 13. The switching device receives the digital signal output from the transmission processing device and outputs the digital signal to a selected transmission antenna. 11. The artificial earth ground station according to any one of 11.