JP2001153682A - Orbit calculation device and orbit calculating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the precision of the calculation of the orbit of an artificial satellite by real time processing. SOLUTION: A parabolic antenna 2 has a link by radio wave with an artificial satellite 1 whose orbit is desired to be calculated. The measuring means 3a of an observation device 3 measures the physical quantities concerning the orbit of the artificial satellite 1 by use of the link by radio wave. A transmitting means 3b transmits the gained physical quantities as observation data to a calculation device 4. In the calculation device 4, a receiving means 4a receives the observation data transmitted from the observation device 3 and supplies it to a first orbit calculating means 4b and a second orbit calculating means 4c. The first orbit calculating means 3b calculates the orbit by batch estimation processing and outputs the result to an output means 4e and a supplying means 4d. The second orbit calculating means 4c calculates the orbit by real time estimation processing in reference to the calculation result by the first orbit calculating means 4b supplied from the supplying means 4d and the observation data, and supplies the result to the output means 4e. The output means 4e displays the calculation results by the first and second orbit calculating means 4b and 3c on a display device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orbit calculation apparatus and an orbit calculation method, and more particularly, to an orbit of a satellite flying while drawing a predetermined orbit in outer space from a physical quantity obtained by observing the satellite. The present invention relates to a trajectory calculation device and a trajectory calculation method.

[0002]

2. Description of the Related Art A batch estimation method and a real-time estimation method are used to calculate the state of an flying object such as an artificial satellite while drawing an orbit in space (position vector and velocity vector at a certain time) based on observation. There is a method.

[0003] The batch estimation method accumulates observation data,
This is a batch processing method. Such a batch estimation method has a feature that a calculation model can be refined and a large amount of observation data is used, so that a highly accurate result can be obtained.

[0004] On the other hand, the real-time estimation method is a method of sequentially processing observation data. Since the processing is performed each time the observation data is acquired, a calculation result can be obtained quickly.

[0005]

However, in the batch estimation method, there is a problem that there is no immediacy because processing is performed at regular time intervals.

In the real-time estimation method, since it is necessary to sequentially process observation data taken at short time intervals (for example, 3 seconds), the model has to be simplified. There is a problem that accuracy is lowered. In addition, the real-time estimation method has a problem that a phenomenon called overconvergence is likely to occur, and a high-precision result cannot be obtained unlike the batch estimation method.
Here, the overconvergence is a phenomenon in which it seems that the accuracy is sufficiently high just by looking at the estimation result covariance matrix indicating the certainty of the estimation, and actually converges to an incorrect result.

[0007] The present invention has been made in view of the above points, and a trajectory calculation system capable of performing an accurate and instantaneous trajectory estimation, a trajectory calculation device constituting such a system, and It is an object to provide a trajectory calculation method.

[0008]

According to the present invention, in order to solve the above-mentioned problems, an orbit calculation device (FIG. 1) for calculating an orbit of a satellite 1 from physical quantities obtained by observing the satellite 1 shown in FIG. A calculating device 4) for calculating a first orbit of the satellite 1 based on the physical quantity by a first method, and a first orbit calculating means 4a for calculating the orbit of the satellite 1 based on the physical quantity according to the first method. A second orbit calculating means 4c for calculating by a different second method, a supplying means 4d for supplying the result obtained by the first orbit calculating means 4b to the second orbit calculating means 4c, And an output unit 4e for outputting a calculation result obtained by the first or second trajectory calculation unit. The trajectory calculation device (calculation device 4) is provided.

Here, the first orbit calculating means 4a calculates the orbit of the satellite 1 based on the physical quantity by the first method. The second orbit calculating means 4c calculates the orbit of the satellite 1 based on the physical quantity by a second method different from the first method. The supply unit 4d supplies the result obtained by the first trajectory calculation unit 4b to the second trajectory calculation unit 4c. The output unit 4e outputs a calculation result obtained by the first or second trajectory calculation unit.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a principle diagram for explaining the operation principle of the trajectory calculation system according to the present invention. In this figure, the artificial satellite 1 is an orbiting satellite, for example, and orbits the earth at a predetermined cycle.

The parabolic antenna 2 has a radio link with the artificial satellite 1 and exchanges information with the artificial satellite 1. The observation device 3 includes a measurement unit 3a and a transmission unit 3b, acquires observation data using a radio link between the artificial satellite 1 and the parabolic antenna 2, and acquires the observation data obtained by the calculation device 4. Send data.

Here, the measuring means 3a measures a physical quantity relating to the movement of the artificial satellite 1 using a radio link between the artificial satellite 1 and the parabolic antenna 2. The transmission means 3b
The data (observation data) of the measurement result of the measuring means 3 a is transmitted to the computing device 4.

The calculating device 4 includes a receiving means 4a, a first trajectory calculating means 4b, a second trajectory calculating means 4c, and a supplying means 4.
d, and output means 4e. The orbit of the artificial satellite 1 is calculated from the observation data supplied from the observation device 3 and displayed on the display device 5.

Here, the receiving means 4a receives the observation data transmitted from the observation device 3. The first orbit calculation means 4b calculates the orbit of the artificial satellite 1 by a batch estimation process which is a first calculation method.

The second orbit calculation means 4c calculates the orbit of the artificial satellite 1 by real-time estimation processing as a second calculation method. The supply means 4d includes a first trajectory calculation means 4b
Is supplied to the second trajectory calculating means 4c.

The output means 4e outputs the calculation results obtained by the first or second trajectory calculation means 4b, 4c to the display device 5. The display device 5 is, for example, a CRT
(Cathode Ray Tube) monitor.
The calculation result supplied from the calculation device 4 is displayed and output.

Next, the operation of the above principle diagram will be described. The measuring means 3a of the observation device 3 uses a radio wave link between the artificial satellite 1 and the parabolic antenna 2 to obtain the transmission time of the radio wave, the change amount of the radio frequency, the elevation angle of the parabolic antenna 2, and the like as observation data. Acquisition and transmission means 3b
To supply.

The transmitting means 3b transmits the observation data supplied from the measuring means 3a to the computing device 4. The receiving means 4a of the calculating device 4 receives the observation data transmitted from the observing device 3, and receives the first orbit calculating means 4b and the second orbit calculating means 4b.
To the trajectory calculation means 4c.

After the first orbit calculation means 4b accumulates the observation data by a certain amount, the error between the accumulated observation data and the calculation data theoretically derived from the equation of motion of the artificial satellite 1 is minimized. The orbit of the artificial satellite 1 is calculated as follows. Therefore, the calculation result is output from the first trajectory calculation means 4b every predetermined time. The result calculated by the first trajectory calculation means 4b is supplied to the supply means 4d and the output means 4e, respectively.

The supply means 4d includes a first trajectory calculation means 4b
Is supplied to the second trajectory calculation means 4c at predetermined time intervals. Second trajectory calculation means 4c
Are the observation data received by the receiving means 4a and the first trajectory calculating means 4b supplied by the supplying means 4d.
With reference to the calculation result, the orbit of the artificial satellite 1 is calculated and output by the real-time estimation processing. Since the second trajectory calculation means 4c sequentially processes the observation data, the second trajectory calculation means 4c outputs the calculation result at the same cycle as the cycle at which the observation data is received.

Here, the second trajectory calculation means 4c is required to sequentially process the observation data,
The calculation is performed using a simpler method than the trajectory calculation means 4b, and "overconvergence" may occur in which the calculation result converges to a solution different from the actual one. In the case of overconvergence, since the estimated result and the actual measurement result agree well, it is often impossible to know that such a state has occurred. It was difficult to depart from the state of over-convergence.

In the present invention, as described above, since the second trajectory calculation means 4c performs the trajectory calculation with reference to the calculation result of the first trajectory calculation means 4b, overconvergence occurs. Can be prevented. That is, in the present invention, the second calculation method (real-time estimation) with high immediateness and low accuracy is interpolated by the result calculated by the first calculation method (batch estimation) with low immediateness and high accuracy. , It is possible to obtain a more accurate calculation result.

Thus, the first trajectory calculating means 4b
The calculation result of the second trajectory calculation means 4c is displayed on the display device 5 via the output means 4e. At this time,
By displaying not only the result calculated by the second trajectory calculation means 4c but also the calculation result by the first trajectory calculation means 4b on the same screen, the error between the two becomes clear at a glance. When an abnormality occurs, it becomes possible to know this immediately.

Next, an example of the configuration of the embodiment of the present invention will be described with reference to FIG. In this figure, the artificial satellite 10 is, for example, an orbiting satellite, and transmits a positioning signal to a ground station.

The parabolic antennas 20 and 21 receive positioning signals transmitted from the artificial satellite 10 at different positions on the earth and supply them to the observation device 30. Observation device 30
Is configured by an observation data acquisition unit 30a and a transmission unit 30b, and generates observation data of the artificial satellite 10 using a positioning signal transmitted from the artificial satellite 10,
The information is supplied to the computing device 50 via the network 40.

Here, as described above, the observation data acquisition unit 30 a uses the positioning signal transmitted from the artificial satellite 10 to transmit the radio wave propagation time, the radio frequency change amount, and the parabolic antenna 20. Obtain the elevation angle etc. as observation data.

The transmission unit 30b is provided with an observation data acquisition unit 30a
Is transmitted to the computing device 50 via the network 40. Network 40
For example, it is configured by a digital line or the like, and the observation data acquired by the observation device 30 is
Transmit to 0.

The computing device 50 includes a receiving unit 50a, a storage unit 5
0b, batch estimation processing section 50c, reference information generation section 50
d, real-time estimation processing section 50e, display processing section 50
f, and a control unit 50g, and based on observation data transmitted from the observation device 30,
The trajectory of zero is calculated and the result is displayed on the display device 60.

Here, the receiving unit 50a is connected to the network 4
0 is received as observation data transmitted. The storage unit 50b stores a predetermined amount of observation data received by the reception unit 50a, and supplies the observation data to the batch estimation processing unit 50c.

The batch estimation processing section 50c includes the artificial satellite 10
Is applied to the Newton's equation of motion taking into account various disturbances (perturbations) received in orbit by applying a motion model that models the acceleration received by the satellite 10 at each observation time. Calculate theoretical orbit information (such as the position vector and velocity vector of the artificial satellite). Then, theoretical observation data is derived by applying an observation model indicating an error received by the observation data at the position to the obtained orbit information.
Finally, the theoretical observation data obtained by calculation,
The orbit of the artificial satellite 10 is calculated so as to compare with actual observation data and minimize the sum of squares of these differences.

The reference information generation unit 50d generates reference information indicating the orbit and the like of the artificial satellite 10 at each observation time from the orbit information calculated by the batch estimation processing unit 50c, and generates a real-time estimation processing unit 50e and a display processing unit. 50
f. Here, the reference information indicates the following data. (A) Position vector and velocity vector of the satellite 10 in the equatorial plane coordinate system (B) Position vector of the ground station (parabolic antennas 20 and 21) in the equatorial plane coordinate system (C) State of the satellite 10 in the equatorial plane coordinate system Transition matrix (D) Observable data acquisition time zone information The state transition matrix is a parameter X according to the equation of motion.
When (t) exists, it can be expressed by the following equation.

[0032]

Φ (t ′, t) = ∂X (t ′) / ∂X (t) (1) In this case, X (t) is a position vector and a velocity vector of the artificial satellite 10. Yes, the physical meaning of Φ indicates how much the position vector or velocity vector at t 'changes when a small change occurs in the position vector or velocity vector at time t. In other words, Φ is an equation that propagates the error of X.

Further, the observation data obtainable time zone information is information indicating a time zone in which the artificial satellite 10 can observe. That is, in the present embodiment, since the artificial satellite 10 is an orbiting satellite, the information indicates a time zone in which the artificial satellite 10 can be observed from the ground.

The real-time estimation processing section 50e performs real estimation processing using the Kalman filter to
Calculate the orbit of. The processing by the Kalman filter is made up of two processings called observation update and time update. In the observation update, the orbit information of the artificial satellite 10 is corrected by applying feedback according to the difference between the acquired observation data and the amount of observation predicted by the Kalman filter. The updated orbit information is propagated until the time when the next observation data is acquired by the time update processing, and receives another update processing there. By repeating such processing, the satellite 10
Trajectory information is sequentially estimated. In the present embodiment, the real-time estimation processing unit 50e sets the estimated value supplied from the batch estimation processing unit 50c as an initial value, and refers to the reference information supplied from the reference information generation unit 50d as described above. The estimation accuracy is improved by performing observation update and time update.

The display processing unit 50f includes a reference information generation unit 50
The d and the trajectory information calculated by the real-time estimation processing unit 50e are supplied to the display device 60 and displayed. The control unit 50g controls each unit of the device.

The display device 60 is constituted by, for example, a CRT monitor or the like, and displays and outputs the image signal supplied from the display processing unit 50f. Next, the operation of the above embodiment will be described.

The positioning signal transmitted from the satellite 10 is
The signals are received by the parabolic antennas 20 and 21 as ground stations and supplied to the observation device 30. Observation device 30
Acquires the positioning signal supplied from the parabolic antennas 20 and 21 as observation data by the observation data acquisition unit 30a, and supplies it to the transmission unit 30b.

The transmitting unit 30b includes an observation data acquiring unit 30a
Is transmitted to the computing device 50 via the network 40. In the calculation device 50,
The observation data transmitted from the observation device 30 is
a.

The observation data received by the receiving unit 50a is supplied to the storage unit 50b and stored therein, and when a certain amount of observation data is accumulated, the observation data is accumulated in the batch estimation processing unit 50c. Observation data is supplied.

The batch estimation processing unit 50c calculates the theoretical value of the orbit information of the artificial satellite 10 by applying the motion model to the motion equation. Next, the observation model is applied to the obtained theoretical value of the orbit information, and the theoretical value of the observation data at the time when each observation data is obtained is calculated. continue,
Orbital information that minimizes the sum of squares of the difference between the theoretical value of the observation data and the actual observation data is calculated,
It is estimated to be the most likely orbital information of 0.

The trajectory information obtained in this way is supplied to the reference information generation unit 50d and is also supplied to the real-time estimation processing unit 50e as initial value information. The reference information generation unit 50d obtains the processing result by the batch estimation processing unit 50c, and based on the obtained processing result, obtains the above (A) to
The reference information (D) is generated and supplied to the real-time estimation processing unit 50e.

The real-time estimation processing section 50e executes the real-time estimation processing with reference to the initial value supplied from the batch estimation processing section 50c. That is, the real-time estimation processing unit 50e sets the Kalman filter using the initial value supplied from the batch estimation processing unit 50c. Then, the Kalman filter set in this manner is subjected to time update processing using the state transition matrix of the reference information, and is also subjected to observation update processing using the trajectory information and the state transition matrix.

FIG. 3 is a diagram showing the relationship between the real-time estimation processing and the batch estimation processing. As shown in this figure, when the input of observation data (see FIG. 3A) is started, these data are accumulated in the storage unit 50b (FIG. 3C).
reference). When a certain amount of observation data is accumulated,
The batch estimation process (see FIG. 3D) is activated, and the initial value and the reference information are supplied to the real-time estimation processing unit 50e. As a result, the real-time estimation processing unit 50e executes the real-time estimation processing with reference to the information and the observation data, and calculates the orbit information of the artificial satellite 10.

Note that the real-time estimation processing section 50e
As shown in FIG. 4, the trajectory information of the reference information derived by the batch estimation processing is defined as a “reference trajectory”, and a deviation Δrk between the reference trajectory at each time and an estimated value by real-time estimation is output as a calculation result.

The display processing unit 50f includes a reference information generation unit 50
d and the estimation result by the real-time estimation processing unit 50e are converted into evaluation target parameters and supplied to the display device 60 for display. The evaluation target parameter is
Since the velocity vector and the position vector, which are the orbit information obtained by the estimation, are each a three-dimensional vector, a value obtained by converting these into an intuitively understandable value (for example, the longitude directly below the satellite 10) is obtained. Say.

FIG. 5 shows the display device 60 as a result of the above processing.
9 is a display example of a screen displayed in FIG. In this display example, the horizontal axis indicates time, and the vertical axis indicates the longitude immediately below. Further, the position where the triangle “△” is attached on the horizontal axis indicates that the reference information has been updated (the processing result by the batch estimation processing has been output). Furthermore,
The bold line indicates the longitude of the point directly below obtained from the result of the batch estimation processing, the broken line indicates the error range of the batch estimation processing, and the thin line indicates the longitude of the point immediately below obtained from the real-time estimation processing.

By referring to such a display screen, it is possible to weigh the result obtained by the real-time estimation processing and the result obtained by the batch estimation processing. If not, it is possible to know that both estimation results are both likely.

Next, details of the processing executed in the embodiment shown in FIG. 2 will be described with reference to FIGS. First, FIG. 6 is a flowchart illustrating an example of an initialization process performed in the batch estimation processing unit 50c. This process corresponds to the first “batch estimation process” shown in FIG. When this flowchart is started, the following processing is executed. [S1] The batch estimation processing unit 50c determines whether or not a certain amount of observation data has been stored in the storage unit 50b. If the observation data has been stored, the process proceeds to step S2; otherwise, the process returns to step S1. And repeat the same processing. [S2] The batch estimation processing unit 50c starts batch estimation processing using the accumulated observation data. [S3] The batch estimation processing unit 50c calculates an initial value of the real-time estimation and supplies it to the real-time estimation processing unit 50e. [S4] The reference information generation unit 50d includes the batch estimation processing unit 5
The trajectory estimation result based on 0c is set as the reference trajectory. [S5] The reference information generating unit 50d propagates the state transition matrix until a predetermined future time (scheduled update time by the next batch estimation).

At this time, a plurality of state transition matrices are generated in advance by propagating at a certain time interval, and these information are appropriately interpolated for the time actually used in the real-time estimation processing. Thus, a state transition matrix at an arbitrary time is obtained. [S6] Reference information generation unit 50
d calculates position information and visible information of the parabolic antennas 20 and 21 which are ground stations.

Here, the position information of the parabolic antennas 20 and 21 indicates the positions and velocity vectors of the parabolic antennas 20 and 21 in an equatorial plane coordinate system which is an inertial coordinate system. Further, the visible information is transmitted by the artificial satellite 10 as described above.
Is information indicating a time zone in which measurement is possible. The reference information generation unit 50d generates such information.

Next, the details of the batch estimation process in the normal state (the second and subsequent batch estimation processes shown in FIG. 3) will be described with reference to FIG. When this flowchart is started, the following processing is executed. [S20] The storage unit 50b stores observation data. [S21] The batch estimation processing unit 50c calculates a prediction error ΔR.

Here, the prediction error ΔR is expressed by the following equation.

[0053]

ΔR = (3n / 2) Δa × T (2) Here, ΔR is an error in the position of the artificial satellite 10 in the traveling direction. Further, n represents the average motion which is the reciprocal of the orbital cycle of the artificial satellite 10, Δa represents the orbital radius error, and T represents the elapsed time from the previous batch estimation processing. [S22] The batch estimation processing unit 50c proceeds to step S23 when the prediction error ΔR is larger than the required regulation ΔRL for operation, and otherwise proceeds to step S20.
And the same processing is repeated.

That is, in the batch estimation processing, the prediction error range is obtained together with the prediction value. However, there is a parameter whose error range increases with time. A typical example is the orbit of the artificial satellite 10 due to the above-described error in the orbital major radius. This is the position error ΔR in the upward traveling direction. Since this ΔR increases with time T as described above, when the value of ΔR exceeds the regulation ΔRL required for operation, a new batch estimation process is performed to compensate for the decrease in accuracy. [S23] The batch estimation processing unit 50c executes a batch estimation process. [S24] The batch estimation processing unit 50c calculates an initial value of the batch estimation processing, and supplies the initial value to the real-time estimation processing unit 50e. [S25] The reference information generation unit 50d sets the prediction result of the trajectory by the batch estimation processing unit 50c as the reference trajectory. [S26] The reference information generator 50d propagates the state transition matrix until a predetermined time (start time of real-time estimation). [S27] The reference information generation unit 50d calculates the initial values of the position information of the parabolic antennas 20, 21 as the ground stations and the initial values of the visible information. [S28] The reference information generation unit 50d updates the reference information. That is, the reference information calculated by the previous batch estimation processing is updated with the new reference information generated by the current processing. [S29] If the process is to be continued, the process returns to step S20, and the same process is repeated. Otherwise, the process ends.

Next, the details of the real-time estimation processing will be described with reference to FIG. When this processing is started, the following processing is executed. [S40] The real-time estimation processing unit 50e outputs the positioning signal transmitted from the artificial satellite 10 to the parabolic antenna 20,
The time t received by 21 is corrected to the actual time t '.

That is, the positioning signal transmitted from the artificial satellite 10 and received by the parabolic antennas 20 and 21 is provided with a tag indicating the reception time. This is corrected because there is a time lag between them. [S41] The real-time estimation processing unit 50e acquires a state transition matrix from the reference information generation unit 50d.

The state transition matrix at the target time is generated by performing an interpolation process and the like as necessary. [S42] The real-time estimation processing unit 50e updates the time of the Kalman filter from the initial value (previous value) to t '.

Here, in the normal time update processing of the real-time processing, the time is updated until a predetermined time by integration. In the present embodiment, the Kalman filter is multiplied by the state transition matrix generated by the batch estimation processing. The time is updated accordingly. Therefore, since integration requiring time for processing can be omitted, processing time can be reduced. Further, since the state transition matrix is generated by batch estimation processing with higher accuracy than real-time processing, it is possible to improve the accuracy of real-time estimation processing. [S43] The real-time estimation processing unit 50e acquires the ground station position information and the visible information from the reference information generation unit 50d, and calculates the ground station position information at time t 'and the visible information at time t' therefrom. I do.

As this calculation method, for example, Hermite interpolation processing can be used. [S44] The real-time estimation processing unit 50e determines whether or not the observation of the artificial satellite 10 is possible from the ground station position information and the visible information acquired in step S43,
If observable, proceed to step S45, otherwise proceed to step S49. [S45] The real-time estimation processing unit 50e performs a process of estimating the time at which the artificial satellite 10 transmitted the positioning signal.

That is, since the artificial satellite 10 moves between the time when the positioning data is transmitted and the time when the satellite data is received, the time at which the positioning signal is transmitted in consideration of the amount of movement is used to determine the time at which the positioning signal is transmitted. Equation). In this case, the reference information generated by the reference information generation unit 50d is used. [S46] The real-time estimation processing unit 50e calculates an error (clock bias) of the clock of the artificial satellite 10.

Since this error is given by a quadratic equation using time as a variable, a clock bias is obtained by solving this quadratic equation. [S47] The real-time estimation processing unit 50e calculates the actual transmission time of the positioning signal from the transmission time obtained in step S45 and the clock bias obtained in step S46. [S48] The real-time estimation processing unit 50e calculates an observation sensitivity matrix.

Here, the observation sensitivity matrix refers to the observed physical quantity h (the distance between the ground station and the artificial satellite, or the direction of the artificial satellite viewed from the ground station, etc.) and the estimation parameter X (in this case, the artificial satellite). Assuming that h (X) is represented as a function of the position vector or the velocity vector (10 position vectors or velocity vectors), the observation sensitivity matrix H is given by the following equation.

[0063]

H = ∂h (X) / ∂X (3) The physical meaning is understood as follows. That is,
The fact that H is large means that the physical quantity h that is observed for a small change in the estimation parameter X greatly changes. In other words, using an observable with a large H,
X can be determined accurately. Conversely, when the observation quantity is small, the change in h is slow relative to the change in X, so that it is difficult to determine X. [S49] The real-time estimation processing unit 50e uses the orbit information and the information transition matrix included in the reference information supplied from the reference information generation unit 50d, and the observation sensitivity matrix calculated in step S48 to calculate the Kalman filter. Execute observation update processing. [S50] If the process is to be continued, the process returns to step S40, and the same process is repeated. Otherwise, the process ends.

As described above, in the embodiment of the present invention, the batch estimation process and the real-time estimation process are executed in parallel, and the result obtained by the batch estimation process is reflected in the real-time estimation process. Therefore, the accuracy of the real-time estimation process can be improved.

Further, since the state transition matrix based on the batch estimation process is used for the time update process of the real-time estimation process, the time update process can be executed with higher accuracy and more quickly.

Further, it is possible to monitor the actual operation accuracy of the real-time estimation processing. This will be described in detail below. That is, the parameters used for the trajectory determination accuracy evaluation are usually the following two types. (A) Covariance matrix (b) Difference between measured value and theoretical value of observation data Here, only the trends (a) and (b) can be evaluated on the spot by real-time estimation processing alone. However, (a) cannot be used as a parameter for evaluating absolute accuracy, as well as in the case of over-convergence. Also,
Regarding (b), although the difference between the measured value and the theoretical value is small, an error may actually be included.

Originally, what is required as “actual operation accuracy” is how much the position of the artificial satellite deviates from the true value. Therefore, it is necessary to compare the results of the real-time estimation processing and the batch estimation processing. It can be said that the method according to the present embodiment that can perform the above is most suitable. In addition, since the real-time estimation process can be performed simultaneously with the actual operational accuracy evaluation of the result, it is possible to eliminate the trouble of performing post-analysis work when a problem occurs as in the past. It becomes possible.

In the above embodiment, the orbiting satellite is the object of observation, but it goes without saying that the geostationary satellite can also be the object of observation. Finally, the above processing functions can be realized by a computer. In this case, the processing contents of the functions that the trajectory calculation device should have are described in a program recorded on a computer-readable recording medium, and the above processing is realized by the computer by executing this program on the computer. Is done. Examples of the computer-readable recording medium include a magnetic recording device and a semiconductor memory. When distributing to the market, CD-ROM (Compact
Disk Read Only Memory) or store the program on a portable recording medium such as a floppy disk and distribute it, or store it on a storage device of a computer connected via a network and transfer it to another computer via the network. Can also. When the program is executed by the computer, the program is stored in a hard disk device or the like in the computer, loaded into the main memory, and executed.

[0069]

As described above, according to the present invention, in an orbit calculation device for calculating the orbit of a satellite from physical quantities obtained by observing the satellite, the orbit of the satellite is calculated based on the physical quantity by the first method. The first orbit calculation means for calculating, the second orbit calculation means for calculating the orbit of the satellite based on the physical quantity by a second method different from the first method, and the first orbit calculation means The result is
Supply means for supplying to the trajectory calculation means of the first or second
And an output unit for outputting the calculation result obtained by the trajectory calculation unit. Therefore, it is possible to easily confirm the accuracy of the trajectory obtained by the calculation.

[Brief description of the drawings]

FIG. 1 is a principle diagram for explaining the operation principle of the present invention.

FIG. 2 is a diagram illustrating a configuration example of an embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a real-time estimation process and a batch estimation process.

FIG. 4 is a conceptual diagram of real-time estimation using a reference trajectory.

FIG. 5 is an example of a display screen displayed on the display device shown in FIG. 2;

FIG. 6 is a flowchart illustrating an example of an initial setting process executed in a batch estimation processing unit illustrated in FIG. 2;

FIG. 7 is a flowchart illustrating an example of a batch estimation process in a normal state.

FIG. 8 is a flowchart illustrating an example of a real-time estimation process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Artificial satellite 2 Parabolic antenna 3 Observation device 3a Measuring means 3b Transmitting means 4 Computing device 4a Receiving means 4b First orbit calculating means 4c Second orbit calculating means 4d Supply means 4e Output means 5 Display device 10 Artificial satellites 20, 21 Parabolic antenna 30 Observation device 30a Observation data acquisition means 30b Transmission means 40 Network 50 Calculation device 50a Receiving unit 50b Storage unit 50c Batch estimation processing unit 50d Reference information generation unit 50e Real-time estimation processing unit 50f Display processing unit 50g Control unit 60 Display device

Claims (6)

[Claims] 1. An orbit calculation device for calculating an orbit of a satellite from physical quantities obtained by observing the satellite, a first orbit for calculating the orbit of the satellite based on the physical quantity by a first method. Calculation means; second orbit calculation means for calculating the orbit of the satellite based on the physical quantity by a second technique different from the first technique; and a result obtained by the first orbit calculation means. A trajectory calculation device comprising: a supply unit that supplies the second trajectory calculation unit; and an output unit that outputs a calculation result obtained by the first or second trajectory calculation unit. 2. The first trajectory calculation means calculates a trajectory by batch estimation, and the second trajectory calculation means calculates a trajectory by real-time estimation and refers to information supplied from the supply means. The trajectory calculation device according to claim 1, wherein the calculation is performed by performing the calculation. 3. The trajectory calculation device according to claim 2, wherein the first trajectory calculation means performs the calculation by the batch estimation processing when the prediction error of the trajectory exceeds a predetermined threshold. 4. The trajectory calculation apparatus according to claim 1, wherein said output means simultaneously displays and outputs the calculation results obtained by said first and second trajectory calculation means. 5. An orbit calculation method for calculating an orbit of a satellite from physical quantities obtained by observing the satellite, wherein a first orbit calculation for calculating the orbit of the satellite based on the physical quantity by a first method. A second orbit calculation step of calculating the orbit of the satellite based on the physical quantity by a second method different from the first method, and a result obtained by the first orbit calculation step,
A trajectory calculation method, comprising: a supply step of supplying to the second trajectory calculation step; and an output step of outputting a calculation result obtained in the first or second trajectory calculation step. 6. A computer-readable recording medium storing a program for causing a computer to execute a process of calculating an orbit of a satellite from a physical quantity obtained by observing the satellite, comprising the steps of: First orbit calculating means for calculating the orbit of the satellite by a first method, second orbit calculating means for calculating the orbit of the satellite based on the physical quantity by a second method different from the first method Supply means for supplying a result obtained by the first trajectory calculation means to the second trajectory calculation means; output means for outputting a calculation result obtained by the first or second trajectory calculation means; A computer-readable recording medium that stores a program that functions as a computer.