All-optical rapid measurement system and method for position and speed of space debris

Abstract

The invention relates to a space debris position and speed all-optical rapid measurement system and method, and relates to the technical field of space debris orbit determination cataloguing. The measuring system comprises a laser, a collimating lens, a central reflection spectroscope, a fast scanning mirror, a narrow-band spectroscope, a telephoto lens, space debris and the like. The time series of key parameters such as the angle, the angular velocity, the distance and the velocity of the space debris relative to the observation platform can be measured at the same time, and the method is used for rapidly determining the space debris orbit. According to the invention, an optical camera with a large aperture, a large field of view and a single-photon detector is used, identification and angle measurement of a plurality of dark and weak space debris can be realized, and rapid measurement of the orbital number of the space debris is realized by adopting laser ranging and speed measurement with a common aperture design. Rapid distance measurement and speed measurement of multiple targets in a view field are realized through laser pulse composite modulation and a fast scanning mirror tracking mechanism, and a more effective solution is provided for the initial orbit element measurement problem of unknown space debris.

Description

Technical Field

[0001] The present invention relates to the technical field of space debris orbit determination and cataloguing, and in particular to a system and method for rapid all-optical determination of the position and velocity of space debris. Background Art

[0002] With the continuous development of human space activities, a large number of retired satellites and faulty satellites have failed to return to the atmosphere and burn up as designed, and disintegrated into large and small space debris, posing a great safety threat to subsequent space activities. How to efficiently and accurately achieve orbit determination and cataloging of space debris, and lay the foundation for collision warning and space debris cleaning, has been a hot issue in space research in recent years. Conventional means of orbit determination and cataloging of space debris are mainly completed by ground-based optical telescopes and ground-based radars. The optical telescope measures the angle information of space debris, and the radar measures the distance and speed information of space debris. The orbit information of space debris is obtained through multi-arc joint solution and cataloging is completed. However, ground-based observation methods are limited by the scope of the country. my country does not have sufficient global observation stations and cannot achieve high-efficiency monitoring of space debris in a timely manner. Space-based monitoring of space debris can effectively make up for this defect and achieve high-efficiency monitoring of the entire sky area. The monitoring payload of space-based space debris is mainly an optical camera to measure the angle information of space debris, with the United States' SBV payload as a typical representative. However, since the angle information can only obtain the angle and angular velocity in the pitch and azimuth directions, it is necessary to rely on long arc segment monitoring and multi-arc segment combination for orbital root calculation, which restricts the application efficiency of space-based monitoring methods. How to achieve rapid measurement of the X, Y, Z three-dimensional position and Vx, Vy, Vz three-dimensional velocity of space debris with a more affordable engineering cost is a common problem faced by the industry.

[0003] In the prior art, there are mainly the following patents that are similar to the present invention:

[0004] Chinese patent document CN202210799712.9 discloses a satellite-borne ultra-long-distance target speed measurement and positioning system and method based on inertial measurement and laser ranging. The speed measurement and positioning system in this technical solution includes a laser rangefinder, a two-dimensional turntable and two fiber optic gyroscopes. The two-dimensional turntable is divided into pitch and azimuth directions. The two fiber optic gyroscopes are respectively installed in the turntable azimuth direction and the turntable pitch direction. The laser rangefinder is installed in the turntable pitch direction. The fiber optic gyroscope is used to measure the pitch and azimuth angular velocity of the two-dimensional turntable. The laser rangefinder is used to measure the relative distance between the satellite and the target. The satellite-borne ultra-long-distance target speed measurement and positioning method based on this technical solution has the advantages of single-star autonomous positioning, high ranging accuracy, high positioning accuracy, and fast positioning speed, and can achieve rapid positioning of a single star. However, the instantaneous field of view of a laser rangefinder is generally only on the order of milliradians, and it is unable to detect and identify space debris within a larger field of view. It is necessary to use prior orbital information to guide the laser rangefinder toward the target, which results in the invention being mainly used for precise measurement of known targets and difficult to use for the discovery and initial orbit determination of unknown targets.

[0005] Chinese patent document CN202211586181.1 discloses a three-dimensional visual measurement method for space targets with a composite of multi-means optical payloads, which relates to the field of aerospace measurement technology. The key points of its technical solution are: S1: long-distance capture tracking measurement; S2: close-range three-dimensional visual measurement; S3: close-range three-dimensional reconstruction; S4: ultra-close-range posture measurement and feature recognition. The present invention can be widely used in intelligent control and measurement and navigation technologies for targets such as space faulty spacecraft and space debris, meeting the detection needs and navigation tasks of space targets at different distances. When the measured target is 200km-20km away from the navigation system, a long-distance visible light camera is used to detect weak targets and provide the navigation system with the target's angle information; when the measured target is 20km-120m away from the navigation system, a visible light camera, infrared camera and laser rangefinder are used to detect the target by multiple means to provide the navigation system with the target's three-dimensional posture information; when the measured space target is 20km-120m away from the navigation system, it is in the close-range three-dimensional visual measurement stage, and the target body changes from a point target to 2°. The visible light camera, infrared camera and laser rangefinder are used to design the same optical axis, and active and passive combined detection and tracking are used to provide the navigation system with the target's three-dimensional posture information. This invention uses the composite optical load of visible light, infrared and laser rangefinders to achieve angle measurement, distance measurement and three-dimensional posture measurement in different distance ranges. However, its working principle determines that its effective range is limited, and it is more suitable for the field of short-range space debris posture measurement. Since this technical solution adopts a common optical axis design for multiple types of payloads, its system structure is complex and its processing and assembly are difficult. In addition, its coaxiality is easily affected by force and heat, and it is not suitable for applications with strict constraints on weight, cost and use environment. In addition, its laser rangefinder has an effective range of only 120 kilometers. If the distance is greater than 120 kilometers, it degenerates into only the visible light camera angle measurement function, which is difficult to adapt to the medium and long-distance conditions of thousands of kilometers in space debris measurement.

[0006] Chinese patent document CN202210748759.2 discloses a satellite-borne active and passive integrated ultra-long-distance single-photon space debris ranging and positioning system and method. The system in this technical solution includes a coarse tracking camera, a tracking turntable and a laser rangefinder. The laser rangefinder is installed parallel to the optical axis of the coarse tracking camera, guided by the target detection position of the coarse tracking camera image, and the jitter of the tracking process is measured by an inertial sensor. The piezoelectric reflector in the laser rangefinder is controlled at high frequency to control the laser emission optical path and the receiving optical path, so that the laser beam covers the remote target, and the echo is detected by a photon counting detector. The target distance and position measurement is achieved in combination with the turntable pointing information. This new active and passive integrated ultra-long-distance single-photon ranging and positioning system and method based on the present invention has the advantages of single-star positioning, high ranging accuracy, and low camera angular resolution requirements. At the same time, the single-photon laser ranging technology is used to achieve ultra-long-distance target position measurement. However, this technical solution adopts a separate design and parallel installation of the coarse tracking camera and the laser rangefinder, which has problems such as complex system architecture, difficult installation and adjustment, and high system cost. In addition, the pulsed laser ranging cannot obtain the speed of the target, which is not conducive to the rapid and accurate orbit determination of space debris.

[0007] Chinese patent document CN202410356854.7 discloses a method, system, medium and device for locating space debris based on single photons. The technical solution is based on a method for locating space debris based on single photons. The original echo light is adaptively de-noised based on singular value decomposition, and the background noise in the original signal is effectively filtered out. The coded pulse sequence and the echo sequence after noise reduction are discrete Fourier transformed in the frequency domain to obtain a more accurate photon flight time. The azimuth angle A and pitch angle E of the space debris fed back by the target tracking module are used to calculate its three-dimensional coordinates, thereby improving the ranging and positioning accuracy of space debris from the algorithm aspect. However, the separation design of the optical system and the ranging system of the tracking module in the technical solution causes the ranging system receiving optical antenna to be unable to share the large-caliber tracking module optical antenna, which is not conducive to receiving the weak reflected light signal of small space debris at a long distance; and the pseudo-random code can only be used for ranging, and the speed information of the space target cannot be obtained, which is not conducive to the rapid determination of the initial orbit of the space debris. Summary of the invention

[0008] The present invention aims to solve the technical problem in the prior art that the initial orbital elements of unknown space debris cannot be quickly determined, and provides a system and method for quickly determining the position and velocity of space debris through full optical technology.

[0009] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0010] An all-optical rapid determination system for the position and velocity of space debris, comprising:

[0011] Lasers, collimating lenses, central reflection beam splitters, fast scanning mirrors, narrow band beam splitters, telephoto lenses, and space debris;

[0012] The light split by the central reflection spectroscope is also transmitted to the infrared lens group and the infrared SPAD detector in sequence;

[0013] The light split by the narrow-band spectroscope is also transmitted to the visible light lens group and the visible light SPAD detector in sequence;

[0014] Also includes:

[0015] A distance measurement and speed measurement unit, wherein the distance measurement and speed measurement unit is connected to the infrared SPAD detector data;

[0016] A laser pulse modulation unit, wherein the laser pulse modulation unit is connected to the laser;

[0017] A laser pointing control unit, wherein the laser pointing control unit is connected to the fast scanning mirror;

[0018] An astronomical positioning angle solving unit is connected to the visible light SPAD detector data.

[0019] In the above technical solution, in the all-optical rapid determination system of the position and velocity of space debris:

[0020] The telephoto lens is used to collect starlight, laser echoes for distance and velocity measurement, and sunlight diffusely reflected by space debris;

[0021] Narrow-band spectroscope is used to transmit laser ranging and speed measurement signals and reflect visible and near-infrared bands;

[0022] The sunlight diffusely reflected by space debris passes through the visible light lens group and is focused and imaged on the visible light SPAD detector;

[0023] The astronomical positioning angle calculation unit is used to obtain the astronomical positioning data of all detectable stars and space debris in the field of view according to the imaging results of the visible light SPAD detector, obtain the star tracks through multi-frame correlation processing and identify them as space debris, and calculate the astronomical positioning data sequence of the space debris according to the relative position relationship between the space debris star tracks and the star map in each frame of the space debris;

[0024] The laser pulse modulation unit drives the laser to emit a laser beam, which is adjusted into a narrow beam laser by a collimating lens and reaches the fast scanning mirror through the central reflection surface of the central reflection beam splitter;

[0025] The laser pointing control unit controls the laser beam to point to a certain space debris according to the astronomical positioning data of the space debris obtained by the astronomical positioning angle solving unit, and emits the laser beam after being collimated by the telephoto lens, and forms a laser echo signal after diffuse reflection by the space debris;

[0026] The laser echo signal is received by the telephoto lens, reflected by the fast-scanning mirror and enters the infrared lens group, and finally focused on the infrared SPAD detector, where the laser echo signal is obtained by photoelectric detection.

[0027] In the above technical solution, the aperture of the optical system in the system is Φ500mm to achieve beam shaping of 1550nm laser.

[0028] In the above technical solution, the beam divergence angle of the optical system in the system is 1μrad~2μrad, so as to reduce the spatial attenuation of the laser and realize ultra-long-distance ranging and speed measurement.

[0029] The all-optical rapid determination method of the position and velocity of space debris applicable to the above-mentioned all-optical rapid determination system of the position and velocity of space debris comprises the following steps:

[0030] Step 1: Obtain visible light image;

[0031] The sunlight diffusely reflected by space debris passes through the visible light lens group and is focused and imaged on the visible light SPAD detector, achieving the acquisition of visible light image star maps with a large field of view and high angular resolution;

[0032] Step 2: Star point extraction and star map recognition;

[0033] The astronomical positioning angle calculation unit obtains the astronomical positioning data of all detectable stars and space debris in the field of view;

[0034] Step 3: Space debris identification;

[0035] Star tracks are obtained through multi-frame correlation processing and identified as space debris;

[0036] Step 4: N space debris angle measurements;

[0037] According to the relative position relationship between the space debris star track and the star map in each frame, the space debris astronomical positioning data sequence is calculated;

[0038] Step 5: Update the list of space debris to be tested;

[0039] The laser pulse modulation unit drives the laser to emit a laser beam, which is adjusted into a narrow beam laser by the collimating lens, and reaches the fast scanning mirror through the central reflection surface of the central reflection beam splitter. The laser pointing control unit obtains the astronomical positioning data of the space debris 11 according to the astronomical positioning angle solving unit;

[0040] Step 6: Laser capture and tracking of a space debris;

[0041] The laser beam is controlled to point to a certain space debris, and then emitted after being collimated by the telephoto lens. The laser echo signal is diffusely reflected by the space debris, and then received by the telephoto lens, reflected by the fast-scanning mirror and entered into the infrared lens group. Finally, it is focused on the infrared SPAD detector, and the laser echo signal is obtained by photoelectric detection. Continuous laser is used to capture and track space debris.

[0042] Step 7: Stable tracking of space debris and prediction of angular velocity;

[0043] When the space debris is stably tracked, the pitch and azimuth velocities of the space debris are calculated and switched to program and energy composite tracking;

[0044] Step 8: Space debris laser ranging and velocity measurement;

[0045] The laser is converted from a continuous laser to a pulse modulated laser, and the distance and speed of the space debris are obtained through the distance measurement and speed measurement calculation unit, as shown in formula (i) and formula (ii) respectively:

[0046] Formula (i);

[0047] Formula (ii);

[0048] Where:

[0049] is the speed of light in a vacuum;

[0050] is the delay of the nth group of laser pulses;

[0051] is the laser ranging distance of the nth group;

[0052] is the laser pulse period of the nth group;

[0053] is the average value of the laser pulse period received by the nth group;

[0054] is the laser speed measurement speed of the nth group.

[0055] The present invention has the following beneficial effects:

[0056] The all-optical rapid determination system and method of the position and velocity of space debris of the present invention can simultaneously measure the time series of key parameters such as the angle, angular velocity, distance, and velocity of space debris relative to the observation platform, and is used for the rapid determination of the orbit of space debris. The present invention uses an optical camera with a large aperture, a large field of view, and a single-photon detector, which can realize the identification and angle measurement of multiple faint space debris, and adopts a common aperture design of laser ranging and velocity measurement to realize the rapid determination of the orbital elements of space debris. The laser pulse composite modulation and the fast scanning mirror tracking mechanism realize the rapid ranging and velocity measurement of multiple targets in the field of view, which provides a more effective solution to the problem of initial orbital element determination of unknown space debris.

[0057] The all-optical rapid determination system and method for the position and velocity of space debris of the present invention utilizes a common optical aperture method for optical imaging and laser ranging and velocity measurement, thereby realizing high-sensitivity passive angle detection and high-precision distance and velocity detection functions for space debris. The system has a compact structure and is engineering feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0059] Figure 1 This is a structural block diagram of the all-optical rapid determination system of the position and velocity of space debris of the present invention.

[0060] Figure 2 Schematic diagram of composite modulation and demodulation for laser ranging and speed measurement.

[0061] Figure 3 The figure is a schematic diagram of the overall process of the all-optical rapid determination method of the position and velocity of space debris of the present invention.

[0062] The reference numerals in the figures indicate:

[0063] 1-Laser; 2-Collimating lens; 3-Central reflection spectroscope; 4-Infrared lens group; 5-Infrared SPAD detector; 6-Fast scanning mirror; 7-Narrow band spectroscope; 8-Visible light lens group; 9-Visible light SPAD detector; 10-Telephoto lens; 11-Space debris; 12-Distance and speed measurement calculation unit; 13-Laser pulse modulation unit; 14-Laser pointing control unit; 15-Astronomical positioning angle calculation unit. DETAILED DESCRIPTION

[0064] The present invention is described in detail below with reference to the accompanying drawings.

[0065] like Figure 1As shown, the all-optical rapid determination system of the position and velocity of space debris of the present invention comprises the following components arranged in sequence in the direction of the optical path: a laser 1, a collimating lens 2, a central reflection beam splitter 3, a fast scanning mirror 6, a narrow-band beam splitter 7, a telephoto lens 10 and space debris 11;

[0066] The light split by the central reflection spectroscope 3 is also transmitted to the infrared lens group 4 and the infrared SPAD detector 5 in sequence;

[0067] The light split by the narrowband beam splitter 7 is also transmitted to the visible light lens group 8 and the visible light SPAD detector 9 in sequence;

[0068] Also includes:

[0069] A distance measurement and speed measurement calculation unit 12, wherein the distance measurement and speed measurement calculation unit 12 is data-connected to the infrared SPAD detector 5;

[0070] A laser pulse modulation unit 13, wherein the laser pulse modulation unit 13 is connected to the laser 1;

[0071] A laser pointing control unit 14, wherein the laser pointing control unit 14 is connected to the fast scanning mirror 6;

[0072] An astronomical positioning angle solving unit 15, wherein the astronomical positioning angle solving unit 15 is data-connected to the visible light SPAD detector 9;

[0073] In the all-optical rapid determination system of the position and velocity of space debris:

[0074] The telescope head 10 as the main optical telescope is a large-aperture reflective system, which is used to collect starlight, laser echoes for ranging and velocity measurement, and sunlight diffusely reflected by space debris 11. The total reflection system ensures that it has high reflectivity in the visible light, near-infrared, and infrared bands, so that the infrared light signal for laser ranging and velocity measurement and the visible light signal diffusely reflected by space debris 11 can share the main optical system, thereby increasing the effective range of laser ranging and velocity measurement;

[0075] The narrowband spectroscope 7 can transmit the laser ranging and speed measurement signals (such as the 1550nm band) and reflect the visible near-infrared band (such as 400nm-900nm). The wavelengths of the two spectra are far apart, which can effectively improve the isolation and prevent the sunlight diffusely reflected by space debris 11 from affecting the laser ranging and speed measurement.

[0076] The sunlight diffusely reflected by the space debris 11 passes through the visible light lens group 8 and is focused and imaged on the visible light SPAD detector 9;

[0077] The astronomical positioning angle solving unit 15 is used to obtain the astronomical positioning data of all detectable stars and space debris 11 in the field of view according to the imaging result of the visible light SPAD detector 9, obtain the star track through multi-frame correlation processing and identify it as the space debris 11, and calculate the astronomical positioning data sequence of the space debris 11 according to the relative position relationship between the star track of the space debris 11 and the star map in each frame of the space debris 11;

[0078] The laser pulse modulation unit 13 drives the laser 1 to emit a laser beam, which is conditioned into a narrow-beam laser by the collimating lens 2, and reaches the fast-scanning mirror 6 through the central reflection surface of the central reflection spectrometer 3; the laser pointing control unit 14 controls the laser beam to point to a certain space debris 11 according to the astronomical positioning data of the space debris 11 obtained by the astronomical positioning angle solving unit 15, and emits the laser beam after being collimated by the telephoto lens 10, and forms a laser echo signal after diffuse reflection by the space debris 11; the laser echo signal is received by the telephoto lens 10, reflected by the fast-scanning mirror 6 and enters the infrared lens group 4, and finally focused on the infrared SPAD detector 5, and the laser echo signal is obtained by photoelectric detection.

[0079] See also Figure 3 The space debris position and velocity all-optical rapid determination method applicable to the space debris position and velocity all-optical rapid determination system of the present invention comprises the following steps:

[0080] Step 1: Obtain visible light image;

[0081] The sunlight diffusely reflected by the space debris 11 passes through the visible light lens group 8 and is focused and imaged on the visible light SPAD detector 9, thereby achieving the acquisition of visible light image star maps with a large field of view and high angular resolution.

[0082] Step 2: Star point extraction and star map recognition;

[0083] The astronomical positioning angle calculation unit 15 obtains the astronomical positioning data of all detectable stars and space debris 11 in the field of view.

[0084] Step 3: Identification of space debris 11;

[0085] The positions of stars remain unchanged in multiple frames, while space debris 11 has relative displacement in multiple frames. The star tracks are obtained through multi-frame correlation processing and identified as space debris 11.

[0086] Step 4: Angle measurement of N space debris 11;

[0087] According to the relative position relationship between the star tracks of N space debris 11 and the star map in each frame, the astronomical positioning data sequence of the space debris 11 is calculated. N is a positive integer.

[0088] Step 5: Update the list of space debris to be tested 11;

[0089] The laser pulse modulation unit 13 drives the laser 1 to emit a laser beam, which is conditioned into a narrow beam laser by the collimating lens 2 and reaches the fast scanning mirror 6 through the central reflection surface of the central reflection spectrometer 3. The laser pointing control unit 14 obtains the astronomical positioning data of the space debris 11 based on the astronomical positioning angle solving unit 15.

[0090] Step 6: Laser capture and tracking of a certain space debris 11;

[0091] The laser beam is controlled to point to a certain space debris 11, and then emitted after being collimated by the telephoto lens 10. The laser echo signal is diffusely reflected by the space debris 11, and the laser echo signal is received by the telephoto lens 10, reflected by the fast scanning mirror 6 and enters the infrared lens group 4, and finally focused on the infrared SPAD detector 5. The laser echo signal is obtained by photoelectric detection. Continuous laser is used to capture and track the space debris 11.

[0092] Step 7: Space debris 11 stable tracking and angular velocity prediction;

[0093] When a certain space debris 11 is stably tracked, the pitch and azimuth angular velocities of the space debris 11 are calculated and switched to program and energy composite tracking.

[0094] Step 8: Laser ranging and velocity measurement of space debris 11;

[0095] The laser is converted from a continuous laser to a pulse modulated laser, and the distance and speed of a space debris 11 are obtained by the distance measurement and speed measurement calculation unit 12, as shown in formula (i) and formula (ii) and Figure 2 shown.

[0096] Formula (i);

[0097] Formula (ii);

[0098] Where:

[0099] is the speed of light in vacuum: m / s;

[0100] is the delay of the nth group of laser pulses, in seconds;

[0101] is the laser ranging distance of the nth group, in meters;

[0102] is the laser pulse period of the nth group, in seconds;

[0103] is the average value of the laser pulse period of the nth group of receivers, in seconds;

[0104] is the laser speed measurement speed of the nth group, unit: meter / second.

[0105] The space debris position and velocity all-optical rapid measurement system of the present invention adopts an optical system with a diameter of Φ500mm to achieve beam shaping of 1550nm laser, and controls the beam divergence angle within 1μrad~2μrad to reduce the laser spatial attenuation and realize ultra-long-distance ranging and velocity measurement.

[0106] The all-optical rapid determination system for the position and velocity of space debris of the present invention uses a visible light SPAD image sensor with a pixel size of 6.4 μm and an array scale of 10240×10240. The F number of the visible light optical system is 2.5, the focal length of the system is 1250 mm, the field of view can reach 3°×3°, the pixel angular resolution is about 1 arc second, the image centroid algorithm accuracy can generally reach 0.1 pixel, and the system angular measurement accuracy is about 0.1 arc second. Calculated at the farthest effective distance of 40,000 km, the azimuth and elevation direction position measurement error corresponding to the angular measurement error is about 20 m.

[0107] In the all-optical rapid determination system of the position and speed of space debris of the present invention, the narrowband spectroscope 7 transmits only the light in the 1550nm±0.2nm band, and the rest of the spectrum is reflected into the visible light imaging optical path, so as to suppress the influence of the diffuse reflected light of the sun on the weak echo signal of the ranging and speed measuring laser; the fast scanning mirror 6 adjusts the direction of the laser output beam through two-dimensional pointing control, completes the scanning within the large field of view of 3°×3°, realizes the detection of laser echo through the infrared lens group 4 and the infrared SPAD detector 5, and the laser pointing control unit 14 realizes the tracking and locking of the space debris and the distance and speed measurement by using the laser echo detection result.

[0108] The all-optical rapid determination method of the position and speed of space debris of the present invention is as follows: in the target search stage (i.e., the capture and tracking stage of the space debris 11), the laser pulse modulation unit 13 controls the laser 1 to output continuous laser, and under the guidance of the astronomical positioning angle solution result, the capture and tracking of the space debris 11 is realized, and the continuous and stable tracking is performed for more than 3 seconds, and the pitch and azimuth angle speeds are calculated, and the fast scanning mirror 6 is controlled to perform program and energy composite tracking, and then the laser output mode is switched to composite modulated pulse laser, and the distance and speed measurement of the space debris 11 is realized through the distance measurement and speed measurement solution unit 12, and then the distance and speed measurement of the next space debris 11 is switched.

[0109] According to the laser ranging link budget, when the laser emission is 1550nm, the average optical power is 100W, and the effective distance is 40,000km, for a space debris diffuse reflector with a diameter of 1m and a reflectivity of 0.5, the infrared SPAD detector receives 6 photons per second, which is close to the limit measurement capability of the system. It is necessary to adopt an ultra-narrow pulse low duty cycle modulation method to emit laser energy in a very short time, reduce the uncertainty of the laser energy packet in the time dimension, and improve the ranging accuracy; when the distance is reduced by N times, the number of received photons increases When the distance is shortened to 5000km, the number of received photons reaches 25000 / second, which can achieve high-precision distance and speed measurement.

[0110] The all-optical rapid determination system and method of the position and velocity of space debris of the present invention can simultaneously measure the time series of key parameters such as the angle, angular velocity, distance, and velocity of space debris relative to the observation platform, and is used for the rapid determination of the orbit of space debris. The present invention designs an optical camera with a large aperture, a large field of view, and a single-photon detector, which can realize the identification and angle measurement of multiple faint space debris, and adopts a common aperture design of laser ranging and velocity measurement to realize the rapid determination of the orbital elements of space debris. The laser pulse composite modulation and the fast scanning mirror tracking mechanism realize the rapid ranging and velocity measurement of multiple targets in the field of view, which provides a more effective solution to the problem of initial orbital element determination of unknown space debris.

[0111] The all-optical rapid determination system and method for the position and velocity of space debris of the present invention utilizes a common optical aperture method to perform optical imaging and laser ranging and velocity measurement functions, thereby realizing high-sensitivity passive angle detection and high-precision distance and velocity detection of space debris. The system has a compact structure and is engineering feasible.

[0112] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An all-optical rapid determination system for the position and velocity of space debris, characterized in that: Including the following arranged in sequence in the direction of the light path: Laser (1), collimating lens (2), central reflection beam splitter (3), fast scanning mirror (6), narrow band beam splitter (7), telephoto lens (10) and space debris (11); The light split by the central reflection beam splitter (3) is also transmitted to the infrared lens group (4) and the infrared SPAD detector (5) in sequence; The light split by the narrow-band beam splitter (7) is also transmitted to the visible light lens group (8) and the visible light SPAD detector (9) in sequence; Also includes: A distance measurement and speed measurement calculation unit (12), wherein the distance measurement and speed measurement calculation unit (12) is data-connected to the infrared SPAD detector (5); A laser pulse modulation unit (13), wherein the laser pulse modulation unit (13) is connected to the laser (1); A laser pointing control unit (14), wherein the laser pointing control unit (14) is connected to the fast scanning mirror (6); An astronomical positioning angle calculation unit (15) is connected to the visible light SPAD detector (9) for data communication.

2. The all-optical rapid determination system for the position and velocity of space debris according to claim 1, characterized in that: The telephoto lens (10) is used to collect starlight, laser echoes for distance and velocity measurement, and sunlight diffusely reflected by space debris (11); The narrow-band spectroscope (7) is used to transmit the laser ranging and speed measurement signals and reflect the visible and near-infrared bands; The sunlight diffusely reflected by the space debris (11) passes through the visible light lens group (8) and is focused and imaged on the visible light SPAD detector (9); The astronomical positioning angle calculation unit (15) is used to obtain astronomical positioning data of all detectable stars and space debris (11) in the field of view according to the imaging result of the visible light SPAD detector (9), obtain star tracks through multi-frame correlation processing and identify the space debris (11), and calculate the astronomical positioning data sequence of the space debris (11) according to the relative position relationship between the star track of the space debris (11) and the star map in each frame of the space debris (11); The laser pulse modulation unit (13) drives the laser (1) to emit a laser beam, which is conditioned into a narrow beam laser by the collimating lens (2), and then passes through the central reflection surface of the central reflection beam splitter (3) to reach the fast scanning mirror (6); The laser pointing control unit (14) controls the laser beam to point to a certain space debris (11) according to the astronomical positioning data of the space debris (11) obtained by the astronomical positioning angle solving unit (15), and emits the laser beam after being collimated by the telephoto lens (10), and forms a laser echo signal after diffuse reflection by the space debris (11); The laser echo signal is received by the telephoto lens (10), reflected by the fast scanning mirror (6) and enters the infrared lens group (4), and finally focused on the infrared SPAD detector (5), and the laser echo signal is obtained by photoelectric detection.

3. The all-optical rapid determination system for the position and velocity of space debris according to claim 1, characterized in that: The optical system in this system has an aperture of Φ500mm to achieve beam shaping of 1550nm laser.

4. The all-optical rapid determination system for the position and velocity of space debris according to claim 1, characterized in that: The beam divergence angle of the optical system in this system is 1μrad~2μrad, which can reduce the spatial attenuation of the laser and achieve ultra-long-distance ranging and speed measurement.

5. A method for rapidly measuring the position and velocity of space debris using an all-optical method for rapidly measuring the position and velocity of space debris according to claim 1, characterized in that: The following steps are involved: Step 1: Obtain visible light image; The sunlight diffusely reflected by the space debris (11) is focused and imaged on the visible light SPAD detector (9) after passing through the visible light lens group (8), thereby achieving the acquisition of a visible light image star map with a large field of view and high angular resolution; Step 2: Star point extraction and star map recognition; The astronomical positioning data of all detectable stars and space debris (11) in the field of view are obtained by an astronomical positioning angle solving unit (15); Step 3: Identification of space debris (11); Star tracks are obtained through multi-frame correlation processing and identified as space debris (11); Step 4: Angle measurement of N space debris (11); Calculating the astronomical positioning data sequence of the space debris (11) according to the relative position relationship between the star track of the space debris (11) and the star map in each frame; Step 5: Update the list of space debris to be detected (11); The laser pulse modulation unit (13) drives the laser (1) to emit a laser beam, which is conditioned into a narrow beam laser by the collimating lens (2), and reaches the fast scanning mirror (6) through the central reflection surface of the central reflection beam splitter (3). The laser pointing control unit (14) obtains astronomical positioning data of the space debris (11) according to the astronomical positioning angle solving unit (15); Step 6: Laser capture and tracking of a certain space debris (11); Controlling the laser beam to point to a certain space debris (11), emitting after being collimated by a telephoto lens (10), forming a laser echo signal after diffuse reflection by the space debris (11), receiving the laser echo signal by the telephoto lens (10), reflecting by a fast scanning mirror (6) into an infrared lens group (4), and finally focusing on an infrared SPAD detector (5), obtaining a laser echo signal through photoelectric detection; using continuous laser to capture and track the space debris (11); Step 7: Stable tracking and angular velocity prediction of space debris (11); When the space debris (11) is stably tracked, the pitch and azimuth velocities of the space debris (11) are calculated and switched to program and energy composite tracking; Step 8: Space debris (11) laser ranging and velocity measurement; The laser is converted from a continuous laser to a pulse modulated laser, and the distance and speed of the space debris (11) are obtained by the distance measurement and speed measurement solution unit (12), as shown in formula (i) and formula (ii) respectively: Formula (i); Formula (ii); Where: is the speed of light in a vacuum; is the delay of the nth group of laser pulses; is the laser ranging distance of the nth group; is the laser pulse period of the nth group; is the average value of the laser pulse period received by the nth group; is the laser speed measurement speed of the nth group.

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