JPH04292300A - Space-suspended matter detection and comminuting method - Google Patents

Abstract

PURPOSE:To provide a newly invented detecting method of a fragment and its comminuting method in response to such controversial points that these fragments suspending in space are rapidly increased along with space development, leading to their collisions with a rocket and a spacecraft. CONSTITUTION:It is composed of a space satellite 2 launched up to an orbit in the neighborhood where a lot of fragments 1 exist, a transmitting station 3 transmitting a searching radio wave 5 for fragments, a command 7 comprising also range information and a control station 4 transmitting and receiving telemetry, and this space satellite is provided with a circuit, finding range difference data from a phase difference between a command an a scattered wave, a control system, solving an equation of solid ellipse, calculating fragment position data and controlling navigation guidance and attitude so as to come close to the fragments, an image processor obtaining image data of the fragment and a laser unit for comminuting the fragment.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for detecting and crushing debris floating in outer space.

0002

[Prior Art] Debris floating in outer space
) (hereinafter referred to as debris), radar has traditionally been used to detect them. The debris does not carry transponders like those found in satellites, so primary radar must be used. FIG. 7 shows the configuration of the primary radar. In the figure, 62 is the radar, 63 is a transmitted wave, 64 is a reflected wave, and 1 is a fragment.

[0003] The radar 62 uses a high-gain antenna to irradiate a beam of radio waves 63 onto a target fragment. This radio wave is transmitted by the effective cross-sectional area of the debris.
on), and this scattered wave is received by the radar 62 again. Since such radar transmission and reception is performed at ground facilities, image acquisition of debris and fragmentation are not performed.

0004

[Math 1]

[0005]

[Problem to be Solved by the Invention] The above "Equation 1" is applied to the characteristics of the primary radar. In this application example, since the debris exists at a higher altitude than around 200 km, the received power of the radar is attenuated in proportion to the fourth power of R and becomes weak. To solve this problem, it is necessary to increase the transmission power and the antenna gain, but this requires increasing the size of the hardware, which causes various problems. For example, an increase in transmission power leads to an increase in the size of the transmitter, but in particular, the method of repeatedly transmitting pulses is a method that transmits radio waves within 200 km from the ground because most of the debris is orbiting at an altitude above 200 km. The power is not being used effectively because the power is being expanded ineffectively. In addition, fragments that are more than 200 km away are only detected by radar, but the actual image of the fragments is not known, and the fragments have not been crushed.

[0006] The present invention has been made to solve this problem, and by easily detecting the position of debris floating in space and detecting the real image of the debris, the need for debris and pulverization can be reduced. This provides a method for crushing fragments after determining the danger.

[0007]

[Means for Solving the Problems] A space floating object detection method according to the present invention involves launching an artificial satellite into an orbit at an altitude of 200 km to 250 km, equipping it with a receiving device or a transmitting device, and installing a transmitting device and a control device on the ground. The two devices are combined to form a set of transmitting and receiving systems, and since the transmitting and receiving functions are separated, continuous waves can be easily used for search radio waves. In addition, since an artificial satellite is placed at approximately the same altitude, this artificial satellite is equipped with a navigation guidance function, an image processing function, and a radar crushing device to approach the debris, obtain images of the debris, and crush the debris. This allows fragments to be crushed after determining necessity and risk.

[0008]

[Operation] In this invention, search radio waves are detected by radio wave propagation in only one direction, so R in "Equation 1" can be equivalently reduced, and since transmission and reception are separated, continuous waves can be detected. It can be used for searching. In addition, the satellite is guided by navigation based on the detected debris's position data and the satellite's position and attitude data, and once it has approached a certain distance, a radar transceiver mounted on the satellite is used to locate the satellite relative to the debris. The system detects the actual image of the debris by approaching it while detecting positional data and taking images of the debris from close range using the satellite's camera. In addition, the image data acquired by the satellite is transmitted to the ground via telemetry, and after determining the necessity and risk of crushing the debris on the ground, it is possible to crush the debris using the satellite's laser irradiation based on a command from the ground. .

[0009]

[Example] Example 1. The basic configuration of this invention is shown in FIG. In the figure, 1 is a fragment, 2 is an artificial satellite, 3 is a transmission facility, 4 is a control station, 5 is a search radio wave for the debris 1 transmitted from the transmission facility 4,
6 is a scattered wave after being scattered by the debris 1; 7 is a command from the control station to the satellite; 8 is telemetry from the satellite to the control station; 9 is a laser beam.

The artificial satellite 2 is placed into an orbit suitable for observing the debris 1. A search radio wave 5 for the debris 1 is transmitted from the transmission equipment 3. When the search radio wave 5 is irradiated to the debris 1, scattering occurs according to the effective cross-sectional area of the debris, and this scattered wave 6 is transmitted to the artificial satellite 2.
received by. The search radio wave transmission azimuth angle (azimuth angle) and elevation angle (
(elevation angle) can be set with high precision. The control station 4 transmits the search radio wave 5 from the transmission equipment 3 at the same time.
The distance (phase difference) can be detected from the distance measurement information of the scattered wave 6 received from the artificial satellite 2 which transmits the command 7 including distance measurement information to the artificial satellite 2 and the distance measurement information of the received command 7. Since the orbit of the artificial satellite 2 has been accurately determined by the control station 4, once the time is known, the position of the debris can be determined with high precision. In addition, based on the position data of the detected debris, the satellite is navigated and brought close to the debris, and the optical sensor installed on the satellite acquires image data of the debris, and this image data is sent to the government as Telemetry 8 Send to 4. The government control station 4 determines the necessity and danger of crushing the fragment 1 based on the image data, and when crushing the fragment 1, sends a crushing execution command included in the command 7. When the artificial satellite 2 receives the crushing execution command, it aims the laser at the debris and irradiates the laser beam 9 to crush the debris.

[0011] A pseudo random noise code (PN code) is used for the ranging information of the command, and a continuous wave modulated to the pseudo random noise code is similarly used for the search radio wave. PN code of command 10 and P of scattered wave 11 received by satellite 2
The relationship between N codes is shown in FIG. 10 is a command, 11 is a PN code serving as distance measurement information of scattered waves, and 12 and 13 are one block of the PN code. 14 is the propagation delay time between the command and the scattered wave.

The blocks of PN codes 12 and 13 are i, j
, k, and is actually made up of a series of combinations of 0 and 1 shown in the figure. 0 and 1
The length of is a value determined by selecting the type of PN code, and the character lengths of i, j, k..., a are the same, and one block is made up of consecutive characters. . Satellite 2 is equipped with a correlator for this PN code,
The phases of the command PN code 10 and the scattered wave PN code 11 can be read. By comparing these two phase differences, the time delay 14 between the command 10 and the scattered wave 11 can be detected.

Since the positions of the artificial satellite 2 and the transmitting equipment 3 are known, and the time delay between the two codes is known, this relationship is expressed by a simple geometric model in FIG. 15 in the diagram
is the x-axis, 16 is the y-axis, 17 and 18 are the foci of the ellipse, 19 is the ellipse, 20 is the line segment connecting the points on the ellipse and the two foci, 21
is a point on the ellipse, 22 is the direction of fragment 1 as seen from point A, 2
3 is the position of fragment 1.

If the position of the artificial satellite 2 is a point B 18 and the position of the transmitting equipment 3 is a point A 17, an x-axis 15 can be defined as a line segment passing through both. The distance between AB is known from orbit determination. The distance between the transmission equipment 3, the debris 1, and the artificial satellite 2 is determined by the distance difference delay time, which is the difference between the time corresponding to the distance between A and B and the time for the scattered wave 6 to reach the artificial satellite 2 via the search radio wave 5. It can be determined from the sum of the distance corresponding to 14 and the distance between AB. The following composition can be created from these two distances. That is, points A17 and B18, which are distant from each other between the artificial satellite 2 and the transmission equipment 3, are the focal point, and one point P' on the ellipse is set as the focal point.
An ellipse 19 can be drawn such that 21 is the sum of the distance corresponding to the distance difference delay time 14 and the distance between AB. If we think about it in two dimensions, the fragment 1 will exist on this ellipse. Since it is actually three-dimensional, the fragment 1 has an ellipse 19 x
It can be seen that it exists on the surface of a spheroid formed when it rotates around its axis. On the other hand, point A 17 assumes transmission equipment 3,
Two angle information, the azimuth angle and the elevation angle, are obtained from the transmission equipment 3 to set the irradiation angle of the search radio wave 5 to the debris 1. Therefore, point A 1
If a straight line is drawn in the irradiation direction 22 from 7 and an intersection point P23 with the spheroid mentioned above is found, this point P23 will be the position of the fragment 1.

FIG. 4 shows a circuit configuration for detecting distance differences in the artificial satellite 2. 24 is an antenna for receiving scattered waves 6;
25 is a reception antenna for command 7, 26 and 27 are receivers, 30 and 31 are local PN code generators, 28 and 29 are comparison circuits, 32 and 33 are integrators and code tracking circuits, and 34 is code difference detection. It is a circuit.

Antenna 24 receives scattered waves 6 and a receiver 26 obtains a video output from the received carrier wave. This output is the same P that the transmitting equipment 3 and the control station 4 have.
It is compared with the output of a local PN code generator 30 composed of N codes, the strength of the correlation is detected by a comparison circuit 28, and code acquisition setting and code tracking are performed by an integrator and code tracking circuit 32. . Similarly antenna 2
5 receives the command 7, and includes a receiver 27, a comparison circuit 29,
Integrator and code tracking circuit 33, local PN code generator 31
This performs the same processing as the scattering described above. For both codes, the local PN code generators 30 and 31 after acquisition always show the same phase as the received code, so by inputting the PN code to the code difference detection circuit 34, the command 7 and the scattered The phase difference between the waves 6, ie the distance difference, can be detected.

FIG. 5 summarizes the algorithm for detecting the position of the fragment 1. 35 is the detection time, 36 is the distance difference data of the scattered wave command, 37 is the position data of the control station, 38
is the position data of the transmitting equipment, 39 is the position data of the artificial satellite obtained by GPSR, 40 is the azimuth angle and elevation angle data of the search radio wave, and 41 is the distance between the government station and the artificial satellite, which is the distance from the transmitting equipment to the artificial satellite. Correction data to be corrected, 42
43 is distance difference data corrected by the correction data 41, 44 is a three-dimensional ellipse equation, and 45 is debris position data.

In order to detect the position of 45 fragments, 42
Distance data from the 43 transmitting facilities to the satellite, distance difference data between the distance from the 43 transmitting facilities to the satellite and the distance from the transmitting facility to the satellite via the debris, and search radio wave data at the 40 transmitting facilities. The direction of irradiation is required. When these three data are used in a calculation, the designated detection time 35 is determined as the designated value, and the calculation is performed using data at a specific time. The position of satellite 2 is GPS
It is obtained from the position data 39 of the artificial satellite obtained by R and the detection time 35. From this data, the position data 37 of the control station 4, and the position data 38 of the transmitting equipment 3, the control station 4
Correction data 41 for correcting the distance of the artificial satellite 2 to the distance from the transmitting equipment 3 to the artificial satellite 2, and distance data 42 from the transmitting equipment 3 to the artificial satellite 2 are obtained. The distance difference data 36 between the scattered wave 6 and the command 7 is corrected to the distance difference data 43 between the distance from the transmitting equipment 3 to the artificial satellite 2 and the distance from the transmitting equipment 3 to the artificial satellite via the debris using the correction data 41. be done. A three-dimensional ellipse equation 44 is obtained from the distance data 42 from the transmitting equipment 3 to the artificial satellite 2 and the corrected distance difference data 43, and is determined by this three-dimensional ellipse equation 44 and the azimuth and elevation angle data 40 of irradiation of the search radio wave 5. The location 45 of the fragment, which is the point of intersection with the straight line, can be obtained.

[0019] Figure 6 shows that after the position of the debris is detected by the satellite, the transmission equipment, and the transmission/reception system of the government agency, the autonomous navigation and guidance function of the satellite approaches the debris, acquires image data of the debris, and transmits telemetry. , which shows the flow of processing up to irradiating laser beams on the fragments when a command to crush the fragments is sent from the government bureau. In the figure, 46 is a tracking command, 47 is on-board software processing that sets the time, control method, and control amount of orbit control maneuver, 48 is relative position data of the satellite and debris, 4
9 is orbit control execution, 50 is first approach completion status,
51 is attitude data from an attitude sensor, 52 is relative attitude data of the debris in the radar coordinate system, 53 is attitude control by an actuator, 54 is detection of debris by radar and approach navigation guidance to the debris, 55 is final approach completion status, 56 57 indicates image processing of the fragments, 57 telemetry of image data, 58 a command to execute the pulverization of the fragments, 59 laser aiming control, 60 aiming coincidence, and 61 laser irradiation.

After detecting the fragment position data of 45, when a tracking command 45 is sent from the government control station, the satellite's onboard software uses the detection time of 35, the satellite position data of 39, and the fragment position data of 45 to determine the relative position. Calculation of position data 48 and calculation 47 of the time, method, and control amount of orbit control maneuver for the artificial satellite to approach the debris are performed. Orbit control 49 is performed according to 47. When the debris approaches a relative position where the radar mounted on the satellite can sufficiently detect it, the first approach completion status 50 is turned on. When the first approach completion status 50 is turned on, attitude control 53 is performed to calculate the direction (relative attitude) of the debris in the radar coordinate system of the artificial satellite and direct the sensitivity axis of the radar toward the debris. Once the radar detects the debris, navigation control and attitude control are carried out to the appropriate position and attitude to take further images5.
4 will be implemented. When the position and attitude are suitable for taking an image, the final approach completion status 55 is turned on, and image processing 56 of the fragments is performed. The image data of the fragments is transmitted as telemetry 57 to the government bureau, and the government bureau determines the necessity and danger of crushing the fragments based on the image data. When a command 58 instructing the execution of crushing is transmitted from the control station and received by the satellite, the onboard software of the satellite performs control 59 to align the laser sight to the debris, and when the sight match status 60 turns on. Laser irradiation 61 is performed.

[0021]

[Effects of the Invention] The present invention has the following effects.

[0022] The orbit of an artificial satellite is set in the vicinity of orbiting debris floating in outer space, and commands including ranging information are sent from the government station to the artificial satellite, and search radio waves are similarly transmitted from the transmission equipment to the debris. Therefore, the position of the debris is determined by a combination of unidirectional radio wave propagation detection, so the above-mentioned "Equation 1" which represents the received power density due to bidirectional radio wave propagation to the debris is used.
Even at orbital altitudes where the R4 term becomes large and the radio waves spread ineffectively, the position of the debris can be easily detected.

Furthermore, the satellite's navigation guidance function and image processing function make it possible to take images of debris from a close distance, and from this image data, the actual nature of the debris, the necessity of crushing the debris, and the dangers of crushing the debris can be determined. Once the nature of the debris has been determined, the debris can be pulverized using a laser beam.

[Brief explanation of drawings]

FIG. 1 shows the basic configuration of the present invention.

FIG. 2 is a diagram showing the relationship between PN codes of command scattered waves.

FIG. 3 is a diagram showing a geometric model of transmission equipment, an artificial satellite, and debris.

FIG. 4 is a diagram showing a circuit configuration for detecting distance differences in an artificial satellite.

FIG. 5 shows a fragment location detection algorithm.

FIG. 6 is a diagram showing the flow of processing from approaching debris using the autonomous navigation and guidance function of the artificial satellite to acquiring image data of the debris.

FIG. 7 is a diagram showing the configuration of a conventional primary radar.

[Explanation of symbols]

1 Fragment 2 Artificial satellite 3 Transmission equipment 4 Government station 5 Search radio wave 6 Scattered wave 7 Command 8 Telemetry 9 Laser beam 10 Command PN code 11 Scattered wave PN code 12 Command PN code 1 block 13 Scattered wave PN code 1 block 14 Propagation delay time between command and scattered wave 15
X axis 16 Y axis 17 Focal point A of the ellipse 18 Focal point B of the ellipse 19 Ellipse 20 A line segment connecting the two foci of the ellipse 21 A point on the ellipse 22 Orientation of the fragment as seen from point A 23 Position of the fragment 24 Scattered waves Receiving antenna 25 Command receiving antenna 26 Receiver for scattered waves 27 Receiver for commands 28 Comparing circuit for scattered waves 29 Comparing circuit for commands 30 Local PN code generator for scattered waves 31 Local PN code generator for commands 32 For scattered waves Integrator and code tracking circuit 33 Command integrator and code tracking circuit 34 Sign difference detection circuit 35 Detection time 36 Distance difference data between scattered waves and commands 37 Government station position data 38 Transmission equipment position data 39 Obtained by GPSR Satellite position data 40 Irradiation direction of search propagation 41 Correction data 42 Distance data between the transmitting equipment and the satellite 43 Distance difference data after being corrected by correction data 44 Three-dimensional ellipse equation 45 Fragment position data 46 Tracking command 47 Orbit Calculation of time, method, and control amount for control maneuver 48 Relative position data between debris and satellite 49 Orbit control 50 First approach completion status 51 Satellite attitude data 52 Relative attitude data of debris in radar coordinate system 5
3 Attitude control 54 Radar navigation guidance and attitude control 55
Final approach completion status 56 Image processing 57 Image data telemetry 58 Crushing execution command 59 Laser aiming control 60 Aiming match status 61 Laser irradiation

Claims (1)

[Claims] [Claim 1] A command containing ranging information is transmitted from a control station on the ground surface to an artificial satellite inserted near a space floating object in orbit, and at the same time a beam of a frequency different from that of the command containing ranging information is transmitted. is irradiated in the direction in which a floating object is to be detected, and when a space floating object is irradiated with this bright beam, the satellite receives scattered waves corresponding to the effective cross-sectional area of the unique radio waves of the space floating object. , the distance difference data obtained from the phase difference between the command and the scattered waves on the satellite, the position data of the satellite obtained separately from the control station, and the beam irradiation direction at the transmitting station are input. The position of the space floating object is detected by calculation, and based on this detected position data, the satellite is guided to approach the space floating object, and upon final approach, the satellite's radar transmitter/receiver is used to bring it closer to the space object. Obtain images of space floating objects using an optical sensor mounted on the satellite, transmit this image data to a government bureau, and have the ground-based government bureau determine the necessity and risk of crushing space floating objects. In this case, a command is sent from a government bureau to an artificial satellite, and in this case, the artificial satellite irradiates the space floating object with a laser to crush it.