JP3218487B2 - Satellite tracking method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite tracking system, and more particularly to a satellite tracking system for predicting a current satellite position using past satellite position information in an automatic satellite tracking system.

[0002]

2. Description of the Related Art In a conventional satellite tracking method for a geostationary satellite, an antenna is moved stepwise little by little while monitoring a reception level of a radio wave transmitted from a geostationary satellite, and a position where the reception level becomes the highest is determined. The search step track method is the mainstream. This step track method is one of the automatic tracking methods.

FIG. 11 shows a conventional automatic tracking system.
The automatic tracking system includes a satellite communication antenna 1, a satellite tracking system receiving unit 2, an antenna angle detecting unit 3,
It has an antenna drive motor control unit 4 and an automatic tracking system arithmetic processing unit 5.

The operation of the conventional automatic tracking system will be described below with reference to FIG.

A radio wave transmitted from a geostationary satellite (not shown) passes through an antenna 1 and is received by a receiver 2 as a received wave. The receiving unit 2 supplies a reception level signal indicating the reception level of the received wave to the automatic tracking system operation processing unit 5. The angle detection unit 3 detects angle information of the antenna 1 (that is, azimuth and elevation). The angle detection unit 3 supplies a detected angle signal representing the detected angle information to the automatic tracking system operation processing unit 5. The automatic tracking system arithmetic processing unit 5 determines the driving direction of the antenna 1 based on the reception level signal and the detected angle signal, and sends a driving command indicating the determined driving direction to the motor control unit 4.
Send to The motor control unit 4 drives the antenna 1 in response to this drive command.

Here, the automatic tracking system arithmetic processing unit 5 compares the reception levels before and after the driving of the antenna 1 and determines the driving direction in the next step so as to move the antenna 1 in a direction in which the reception level becomes higher. The geostationary satellite is tracked by repeating this step operation.

Referring to FIG. 12, the operation of the automatic tracking system arithmetic processing unit 5 will be described. The automatic tracking system arithmetic processing unit 5 determines whether the reception level is normal (step S).
1). When the reception level is normal (YE in step S1)
S), as described above, the automatic tracking method arithmetic processing unit 5
Antenna 1 by automatic tracking system by motor control unit 4
Is driven (step S2). Here, when the reception level is abnormal (NO in step S1), that is, when the reception level becomes equal to or less than a predetermined reference value, or when the reception level fluctuates so strongly that the driving direction of the antenna 1 cannot be determined, The automatic tracking system arithmetic processing unit 5 interrupts the driving of the antenna 1 by the motor control unit 4. When the reception level becomes equal to or higher than the reference value and the level fluctuation becomes stable, the automatic tracking system arithmetic processing unit 5 restarts the tracking operation of the geostationary satellite.

In addition to the above-described automatic tracking method, a satellite tracking method described below is known. One is an 11-element ESS-412 program tracking method in which the position of a geostationary satellite is calculated using an orbital element of the geostationary satellite without using a received wave. The other is to use the fact that the movement of the geostationary satellite is in a one-day cycle, and to add the angle information one cycle before or the angle information two cycles before to the angle information one cycle before to determine the position of the geostationary satellite. This is a memory tracking method for calculating. These satellite tracking methods are both used as backup methods of the automatic tracking method described above.

[0009]

In the above-described conventional satellite tracking system, which uses a received wave, satellite tracking is interrupted when the reception level decreases or the reception level greatly fluctuates. During the suspension of the satellite tracking, the automatic tracking becomes impossible unless the geostationary satellite moves greatly and the reception level does not return. In particular, recently, there is a tendency that the north-south orbit holding is gently operated in order to extend the operational life of the geosynchronous satellite.

In the backup memory tracking method, in the case of a scintillation phenomenon in which the reception level fluctuates at the same time every day, the angle information one cycle before or two cycles before cannot be captured. Therefore, such a case cannot be handled by the memory tracking method. Even in such a case, backup by the above-mentioned ESS-412 program tracking method is possible. However, IESS-
In the 412 program tracking method, it is necessary to periodically obtain the values of 11 orbital elements from the satellite operation center.

Further, in the step track system, which is one of the automatic tracking systems, there is a problem that the antenna drive mechanism is greatly consumed because the antenna is frequently reciprocated.

Accordingly, it is an object of the present invention to provide a satellite tracking system which enables automatic tracking of a geostationary satellite even when automatic tracking of the geostationary satellite by the automatic tracking system becomes impossible due to fluctuations in the reception level. It is in.

[0013]

According to the present invention, there is provided a system for tracking a geosynchronous satellite, wherein satellite trajectory information of the geosynchronous satellite captured by an automatic tracking system from an angle detection unit of an antenna is stored in a satellite position storage unit. When the information amount of the stored satellite trajectory information becomes 24 hours or more, a predetermined satellite trajectory function is processed by the linear regression analysis operation processing unit using the stored satellite trajectory information.
Is calculated by performing a linear regression analysis using the least squares method.
Current prediction of geostationary satellites by substituting the estimated coefficients into the satellite trajectory function
When the position is calculated and the tracking of the geostationary satellite by the automatic tracking method becomes impossible, the geostationary satellite is tracked according to the calculated current predicted position of the geostationary satellite.

[0014]

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

Referring to FIG. 1, the satellite tracking system according to one embodiment of the present invention is shown in FIG. 11 except that it has a satellite position storage unit 6 and a linear regression analysis operation processing unit 7. It has a configuration similar to the one described above. Therefore, FIG.
The same reference numerals are given to components having the same functions as the components shown in (1), and description thereof is omitted.

The satellite position storage unit 6 has a storage capacity capable of storing satellite trajectory information for 48 hours or more, and automatically and automatically stores satellite tracking position information (satellite trajectory information) by automatic tracking. When the information amount of the satellite trajectory information stored in the satellite position storage unit 6 becomes 24 hours or more, the linear regression analysis operation processing unit 7 performs a linear regression analysis by the least square method using the stored satellite trajectory information. Calculate the location of the geostationary satellite.

The operation of the satellite tracking system shown in FIG. 1 will be described with reference to FIG. The radio wave propagated from the geostationary satellite passes through the antenna 1 and is received by the receiver 2 as a received wave. The receiving unit 2 transmits a reception level signal indicating the reception level of the received wave to the automatic tracking system operation processing unit 5.

In response to the reception level signal, the automatic tracking system arithmetic processing unit 5 monitors the reception level. If the reception level is normal (YES in step S1), the automatic tracking system arithmetic processing unit 5 determines the driving direction of the antenna 1 in the next step, and sends a driving command indicating the determined driving direction to the motor control unit 4. Then, the antenna 1 is driven by the motor control unit 4 (step S2). When the maximum point of the reception level by the automatic tracking method is detected, the automatic tracking method calculation processing unit 5 stores the detected angle signal representing the angle information obtained from the angle detection unit 3 in the satellite position storage unit 6 as the satellite trajectory information. (Step S3). Here, it should be noted that the angle information, that is, the position of the geostationary satellite is represented by two components, an azimuth angle and an elevation angle.

When the reception level becomes abnormal (NO in step S1) and the driving of the antenna 1 by the automatic tracking method becomes impossible, the automatic tracking method calculation processing unit 5 outputs a tracking impossible signal indicating that tracking is impossible. It is sent to the linear regression analysis operation processing unit 7. In response to this tracking impossible signal, the linear regression analysis operation processing unit 7 determines that the information amount of the satellite trajectory information stored in the satellite position storage unit 6 is 24 hours or more (YE in step S4).
S), a linear regression analysis by the least squares method is performed using the satellite trajectory information, and a coefficient of a satellite trajectory function (described later) to be applied is calculated (step S5). The linear regression analysis operation processing unit 7 calculates the current position (angle) of the geostationary satellite using the above-mentioned coefficient (step S6), and sends a position signal indicating the calculated position to the motor control unit 4. In response to the position signal, the motor control unit 4 drives the antenna 1 (Step S7).

As described above, the motor control unit 4 responds to either the drive command sent from the automatic tracking system operation processing unit 5 or the position signal sent from the linear regression analysis operation unit 7 to The antenna 1 is driven to the angle indicated by the angle (step S2 or step S7).

Various satellite trajectory functions can be applied to the linear regression analysis by the least square method.

Referring to FIG. 3, the satellite tracking method according to the first embodiment of the present invention uses the following equation 6 as a satellite trajectory function.

[0023]

(Equation 6)

Here, y indicates the position of the geostationary satellite, and sin
(T) indicates a sine function having a cycle of 24 hours, A and D indicate the amplitude and phase of the sine function sin (t) to be determined by linear regression analysis, and C indicates a position deviation.

The use of the above equation 6 for this satellite trajectory function is effective for short-time backup tracking when the trajectory information amount is small. However, the satellite trajectory function represented by Equation 6 is not suitable because the error increases when the trajectory of the geostationary satellite has a large drift component or a divergent contraction component of amplitude.

Referring to FIG. 4, the satellite tracking method according to the second embodiment of the present invention uses the following equation 7 as a satellite trajectory function taking such components into consideration.

[0027]

(Equation 7)

Here, y indicates the position of the geostationary satellite, and sin
(T) shows a sine function with a period of 24 hours, and A, E
And D respectively indicate the amplitude, amplitude velocity deviation (divergence contraction component of amplitude) and phase of the sine function sin (t) to be obtained by linear regression analysis, and B and C represent velocity deviation (drift component) and position deviation, respectively. .

The satellite trajectory function represented by Equation 7 is effective when a trajectory information amount of 48 hours or more can be obtained in order to obtain practical accuracy.

Referring to FIG. 5, a satellite tracking system according to a third embodiment of the present invention is an example in which the advantages of the first and second embodiments are combined and utilized. That is, in the third embodiment, when the information amount of the satellite trajectory information stored in the satellite position storage unit 6 is not less than 24 hours and less than 48 hours (NO in step S4 '), the above equation 6 is used as the satellite trajectory function. When the information amount of the satellite trajectory information stored in the satellite position storage unit 6 is 48 hours or more (Y in step S4 ').
ES) uses Equation 7 above as the satellite trajectory function.

Incidentally, in general, the satellite track information itself stored in the satellite position storage unit 6 includes an error of the automatic tracking itself. In order to improve the calculation accuracy of the tracking angle, it is desirable to adopt another two embodiments as described below.

Referring to FIG. 6, the satellite tracking method according to the fourth embodiment of the present invention includes steps S51 and S5 between step S5 and step 6, which will be described later.
2 is the same as that shown in FIG. 2 except that 2 is added. After performing the linear regression analysis by the least squares method using the satellite trajectory information stored in the satellite position storage unit 6, the linear regression analysis operation processing unit 7 deletes the trajectory information having a large error from the satellite position storage unit 6 ( (Step S51), the coefficients of the linear regression analysis are recalculated (Step S52). That is, the linear regression analysis operation processing unit 7 deletes large trajectory information having a certain error or more between the angle calculated using the obtained coefficient and the trajectory information obtained by the latest automatic tracking for several hours. To recalculate the coefficients.

Referring to FIG. 7, the satellite tracking system according to the fifth embodiment of the present invention includes a step S51a and a step S51, which will be described later, between steps S5 and S6.
It is the same as that shown in FIG. 2 except that 52a is added. After performing a linear regression analysis by the least squares method using the satellite trajectory information stored in the satellite position storage unit 6, the linear regression analysis operation processing unit 7 replaces the trajectory information with a large error with a calculated value (step S51a), The coefficients of the linear regression analysis are recalculated (step S52a). In other words, the linear regression analysis operation processing unit 7 calculates large trajectory information having a certain or more error between the angle calculated using the obtained coefficient and the trajectory information obtained by the latest automatic tracking for several hours. And recalculate.

Referring to FIG. 8, the satellite tracking method according to the sixth embodiment of the present invention is more advantageous than the step track method, which is one of the automatic tracking methods, in order to extend the life of the mechanism of the antenna 1. Is a method that gives priority to the method of (1).

First, if the information amount of the satellite trajectory information stored in the satellite position storage unit is less than 24 hours (N in step S4)
O), if the reception level is normal (YES in step S1), the step-track-type operation processing unit performs the antenna drive by the step-track method (step S2a),
The satellite trajectory information is stored in the satellite position storage unit.

On the other hand, if the information amount of the satellite trajectory information stored in the satellite position storage unit is 24 hours or more (YE in step S4)
S), the step track method arithmetic processing unit determines whether or not it is the angle storage time (step S8). If it is the angle storage time (YES in step S8), the step track method arithmetic processing unit determines whether the reception level is normal (step S8).
1a) If it is normal, the process moves to step S2a. When the reception level is abnormal (NO in step S1a) and when it is not the angle storage time (NO in step S8), the step track method operation processing unit activates the linear regression analysis operation processing unit. The activated linear regression analysis operation processing unit stores the satellite position storage unit 6
A linear regression analysis based on the least squares method is performed using the satellite trajectory information stored in the satellite, and the coefficient of the satellite trajectory function to be applied is calculated (step S5), and the current position (angle) of the geostationary satellite is calculated using the aforementioned coefficient. Is calculated (step S6), and a position signal indicating the calculated position is sent to the motor control unit 4 to drive the antenna 1 (step S7).

Referring to FIG. 9, a satellite tracking system according to a seventh embodiment of the present invention is a modification of the third embodiment shown in FIG. That is, in the seventh embodiment, in the third embodiment, when the trajectory of the geostationary satellite is switched between the increase and decrease of the drift and the divergence and contraction of the amplitude by the acceleration component, an increase in the error due to the corresponding transmission is performed. This is a method in which switching to the method of the first embodiment shown in FIG. 3 is added for correction.

That is, when the information amount of the satellite trajectory information stored in the satellite position storage unit 6 is not less than 24 hours and less than 48 hours, the linear regression analysis calculation processing is performed as in the first embodiment shown in FIG. The unit 7 calculates coefficients A, D, and C by performing a linear regression analysis using Equation 6 as a satellite trajectory function (step S5a), and calculates an angle using the obtained coefficients (step S5).
6a), a position signal indicating the calculated angle is sent to the motor control unit 4 to drive the antenna 1 (step S7).

On the other hand, when the information amount of the satellite trajectory information stored in the satellite position storage unit 6 is 48 hours or more, the linear regression analysis operation processing unit 7 performs The coefficients A, D, and C are calculated by performing a linear regression analysis (step S5a), the angle is calculated with the obtained coefficients (step S6a), and further (YE in step S4 ').
S), linear regression analysis is performed on the satellite trajectory function represented by Expression 7 to calculate coefficients A, B, C, D, and E (step S5b), and an angle is calculated using the obtained coefficients (step S5b). S6b). Then, the linear regression analysis operation processing unit 7 determines the drive angle as follows (step S10). That is, the linear regression analysis operation processing unit 7 calculates the two angles (driving angles based on the satellite trajectory function) obtained as described above.
The difference between the trajectory information and the trajectory information by the automatic tracking method is compared over the past several hours, and the drive angle by the satellite trajectory function with the smaller error is selected. Then, the linear regression analysis operation processing unit 7
Sends a position signal indicating the selected drive angle to the motor control unit 4 to drive the antenna 1 (step S
7).

Referring to FIG. 10, the satellite tracking system according to the eighth embodiment of the present invention differs from the second embodiment shown in FIG. 4 in that a component of (1/2) period is further added to the satellite trajectory function. This is an embodiment in which the accuracy is improved. That is, in this embodiment, the linear regression analysis operation processing unit 7 uses the following Expression 8 as a satellite trajectory function.

[0041]

(Equation 8)

Here, y indicates the position of the geostationary satellite, and sin
(T) and sin (2t) are 24 hours and 12 hours, respectively.
FIG. 4 shows first and second sine functions having a period of time, wherein A,
E and D indicate the amplitude, amplitude velocity deviation and phase of the first sine function sin (t) to be determined by linear regression analysis, respectively, and F, G and H respectively indicate the second sine function sin to be determined by linear regression analysis. (2t) represents the amplitude, amplitude velocity deviation and phase, and B and C represent velocity deviation and position deviation, respectively.

The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0044]

As described above, the satellite tracking method according to the present invention has a satellite position storage unit and calculates and predicts the satellite position using the satellite trajectory information of the past 24 hours or more. Even if it fluctuates or disappears, there is an effect that the automatic tracking of the geostationary satellite becomes possible. Further, since the linear regression analysis by the least squares method is used for the prediction calculation of the satellite position, there is an effect that the automatic tracking can be performed even if the angle information is not obtained at the same time every day in the past satellite trajectory information.
Furthermore, by using the method of the present invention with priority over the step track method, which is one of the automatic tracking methods, there is an effect that the number of times of reciprocating driving of the antenna can be reduced and the life of the antenna mechanism can be extended. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a satellite tracking system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a basic operation of the satellite tracking system shown in FIG.

FIG. 3 is a flowchart illustrating a satellite tracking method according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a satellite tracking method according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating a satellite tracking method according to a third embodiment of the present invention.

FIG. 6 is a flowchart illustrating a satellite tracking method according to a fourth embodiment of the present invention.

FIG. 7 is a flowchart illustrating a satellite tracking method according to a fifth embodiment of the present invention.

FIG. 8 is a flowchart illustrating a satellite tracking method according to a sixth embodiment of the present invention.

FIG. 9 is a flowchart illustrating a satellite tracking method according to a seventh embodiment of the present invention.

FIG. 10 is a flowchart illustrating a satellite tracking method according to an eighth embodiment of the present invention.

FIG. 11 is a block diagram showing a conventional satellite tracking system.

12 is a flowchart showing the operation of the satellite tracking system shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Receiving part 3 Angle detecting part 4 Motor control part 5 Automatic tracking method arithmetic processing part 6 Satellite position storage part 7 Linear regression analysis arithmetic processing part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-129767 (JP, A) JP-A-62-44679 (JP, A) JP-A-52-2296 (JP, A) 119407 (JP, A) JP-A-5-233683 (JP, A) JP-A-7-27843 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S 3/00-3 / 74 H01Q 3/00-3/20

Claims (10)

(57) [Claims] 1. A method for tracking a geostationary satellite, comprising: storing satellite trajectory information of the geostationary satellite acquired by an automatic tracking system from an angle detection unit of an antenna in a satellite position storage unit; When the amount of information exceeds 24 hours , a linear regression analysis operation is performed using the stored satellite track information.
The least square method for the predetermined satellite trajectory function in the processing unit
The coefficient calculated by performing a linear regression analysis is referred to as the satellite trajectory function.
To calculate the current predicted position of the geostationary satellite, and when the tracking of the geostationary satellite by the automatic tracking method becomes impossible, tracking the geostationary satellite according to the calculated current predicted position of the geostationary satellite. Satellite tracking method characterized by the following. 2. The linear regression analysis operation processing unit calculates the following formula 1 as a function formula applied to the linear regression analysis by the least squares method. (Where y indicates the position of the geostationary satellite, sin (t)
Indicates a sine function having a period of 24 hours, A and D indicate the amplitude and phase of the sine function to be determined by the linear regression analysis, respectively, and C indicates a position deviation. 2. The satellite tracking method according to claim 1, wherein 3. The linear regression analysis operation processing unit calculates the following equation (2) as a function equation applied to the linear regression analysis by the least square method. (Where y indicates the position of the geostationary satellite, sin (t)
Indicates a sine function with a period of 24 hours, and A, E and D
Indicates the amplitude, amplitude velocity deviation and phase of the sine function to be obtained by the linear regression analysis, respectively, and B and C
Indicates a speed deviation and a position deviation, respectively. 2. The satellite tracking method according to claim 1, wherein 4. The linear regression analysis operation processing unit, as a function formula applied to the linear regression analysis by the least squares method, when the information amount of the stored satellite trajectory information is 24 hours or more and less than 48 hours, and 48 hours or more. At the time,
Equations 3 and 4 below (Equation 4) (Where y indicates the position of the geostationary satellite, sin (t)
Indicates a sine function with a period of 24 hours, and A, E and D
Indicates the amplitude, amplitude velocity deviation and phase of the sine function to be obtained by the linear regression analysis, respectively, and B and C
Indicates a speed deviation and a position deviation, respectively. 2. The satellite tracking method according to claim 1, wherein 5. The linear regression analysis operation processing unit according to claim 1, wherein an error between the angle calculated by using the obtained coefficient and the trajectory information obtained by automatic tracking for the latest several hours has a certain or larger large trajectory information. 2. The satellite tracking method according to claim 1, wherein the coefficient is deleted and the coefficient is calculated again. 6. The linear regression analysis operation processing unit includes: a large trajectory information having an error between an angle calculated by using the obtained coefficient and trajectory information obtained by automatic tracking for the latest several hours; 2. The satellite tracking method according to claim 1, wherein the calculation is replaced with a calculated value and the calculation is performed again. 7. The satellite according to claim 1, wherein, when the information amount of the satellite trajectory information stored in the satellite position storage unit becomes 24 hours or more, except for taking in new trajectory information, the automatic tracking method is used. 2. The satellite tracking system according to claim 1, wherein the tracking system is performed with priority. 8. A calculated value obtained by the method according to claim 2 and a calculated value obtained by the method according to claim 3.
A satellite tracking method characterized in that errors from track information obtained by automatic tracking for the latest several hours are respectively obtained, and the method is switched to a method with a small error. 9. The linear regression analysis operation processing unit calculates the following formula 5 as a function formula applied to the linear regression analysis by the least square method. (Where y indicates the position of the geostationary satellite, sin (t)
And sin (2t) denote the first and second sine functions with a period of 24 hours and 12 hours, respectively, where A, E and D are the amplitudes of the first sine function to be determined by the linear regression analysis, respectively. Indicates amplitude velocity deviation and phase,
F, G, and H respectively indicate the amplitude, amplitude velocity deviation, and phase of the second sine function to be obtained by the linear regression analysis, and B and C represent the velocity deviation and the position deviation, respectively. 2. The satellite tracking method according to claim 1, wherein 10. An automatic tracking system capable of backing up and tracking a geostationary satellite when it becomes impossible to track a geostationary satellite by an auto-tracking method. An angle detection unit for detecting an angle of an antenna A satellite position storage unit having a storage capacity capable of storing satellite trajectory information of the geosynchronous satellite acquired by the automatic tracking method from the satellite tracking device for 48 hours or more; and an information amount of the satellite trajectory information stored in the satellite position storage unit When 24 hours or more, a coefficient of the satellite trajectory function is calculated by performing a linear regression analysis by a least squares method on a predetermined satellite trajectory function using the stored satellite trajectory information, and the calculated A linear regression analysis processing unit for calculating a current predicted position of the geostationary satellite by substituting a coefficient into the satellite trajectory function.