Satellite system and computer-implemented method for monitoring and detecting space objects in the area of space close to a celestial body, data processing system, computer program, and computer-readable medium

Abstract

The invention relates to a satellite system (100) for monitoring and detecting space objects (102) in the area of space close to a celestial body, in particular for monitoring and detecting space debris, preferably for determining at least one object property of the space objects (102), comprising satellites (108, 110, 112, 114, 160) located on at least one first main orbit (104). Each of the satellites (108, 110, 112, 114, 160) has an observation device (164) which is mounted and designed so as to generate images of space objects (102) within an observation field (108b, 110b, 112b, 114b), and the at least one first main orbit (104) has an orbit height (178, 182) between 200 km and 800 km such that space objects (102) to be observed are preferably located at the same orbit height or higher orbit heights (178, 182) in order to align the observation field (108b, 110b, 112b, 114b) away from the celestial body (106).

Description

[0001] HEESCHEN.PULTZ

[0002] PATENT ATTORNEYS

[0003] Hamburg, August 20, 2025 Our reference: P-2024-041 DE DH / db

[0004] Applicant / Owner: Vyoma GmbH, Karl-Theodor-Str. 55, 80803 Munich

[0005] Official file number: PCT retroactive registration

[0006] Satellite system and computer-implemented method for monitoring and detecting space objects in near-celestial space, data processing system, computer program and computer-readable medium

[0007] The invention relates to a satellite system and a computer-implemented method for monitoring and detecting space objects in near-celestial space, a data processing system, a computer program, and a computer-readable medium. Satellite systems for monitoring and detecting space objects in near-celestial space, particularly for monitoring and detecting space debris, are generally known. Space objects are observed using telescopes and radar stations located on Earth. Space debris is an undesirable byproduct of space travel because it hinders space travel and can cause damage to satellites and spacecraft.

[0008] The Earth is orbited by more than 55,000 currently detected and cataloged space objects with a diameter greater than 10 cm. Based on statistical models, the ESA estimates that there are more than 1 million objects larger than 1 cm in near-Earth space. Such space objects can collide with active satellites or spacecraft and, due to the high relative speeds in space, typically cause considerable damage in such collisions.

[0009] While telescopes and radar stations located on Earth can detect and catalog celestial objects in Earth orbit, these approaches are generally insufficient for commercial spaceflight because smaller objects also need to be detected, and a higher temporal resolution is particularly required. Furthermore, the spatial resolution of this approach is usually inadequate, as observation is either impossible or severely limited, especially at high latitudes. In addition, the quality of observations is affected by weather conditions, particularly cloud cover.

[0010] One approach to observing celestial objects with telescopes is called staring. Staring involves maintaining a fixed orientation relative to the starry background during image exposure. As a result, stars appear as points in the image, while closer objects, such as celestial objects in Earth's orbit, produce a line-like signal due to their relative motion. The length and shape of this signal are determined by the exposure time. Such line-like signals are also known as streaks.

[0011] Another approach is called tracking. With tracking, the object of interest is followed along the telescope's optical axis, thus minimizing its motion in the image. To a first approximation, the object produces a point-like signal, while the background stars are represented by line-like image elements. One disadvantage of tracking is that only a single object can be observed during a single observation interval. Furthermore, the field of view must be shifted to another object between observation intervals, resulting in a low throughput of observed objects, which is another drawback of tracking. Additionally, the orbit of the object to be observed must be known approximately a priori.

[0012] When observing space objects using a telescope on a satellite, current approaches typically involve optimizing the observation conditions relative to the object being observed, for example, by minimizing the solar phase angle. This usually results in a less than optimal number of objects being observed.

[0013] The publication by Krag, H., et al., "Space based optical observation of small debris objects," Space Debris, Vol. 473, 2001, reveals a satellite-based observation of space debris using a telescope. A disadvantage of this approach is that, at least in certain regions of the satellite's own orbit and in certain orbital regimes of the objects of interest, few or no observations can be obtained.

[0014] The publication “Proceedings of the 1998 Space Control Conference, Project Report, STK-253, 14-16 April 1998, Lincoln Laboratory, Massachusetts Institute of Technology, page 119 ff.” describes an optical sensor fence that is stretched around the Earth. This involves creating a circular surveillance area around the Earth. A disadvantage of this approach is the short potential observation time and the fact that the objects to be observed are rarely, if ever, detected. Furthermore, the objects can only be observed with limited quality.

[0015] It is an object of the invention to provide a satellite system and a computer-implemented method for monitoring and detecting space objects in near-Earth space, a data processing system, a computer program, and a computer-readable medium that reduce or eliminate one or more of the aforementioned disadvantages. In particular, it is an object of the invention to provide a solution that enables the cataloging of space debris in near-Earth space.

[0016] This problem is solved by a satellite system, a computer-implemented method, a data processing system, a computer program, and a computer-readable medium according to the features of the independent claims. Further advantageous embodiments of these aspects are specified in the respective dependent claims. The features disclosed in the claims, the description, and the drawings can be combined individually, in any technologically meaningful way, and further embodiments of the invention are shown.

[0017] According to a first aspect, the aforementioned problem is solved by a satellite system for monitoring and detecting space objects in near-celestial space, in particular for monitoring and detecting space debris, preferably for determining at least one property of the space objects, comprising satellites arranged on at least one first principal orbit, wherein each of the satellites has an observation device which is arranged and configured to produce images of space objects within an observation field, wherein the at least one first principal orbit has an orbital altitude between 200 km and 800 km, so that space objects to be observed are preferably located at the same or a greater orbital altitude in order to orient the observation field away from the celestial body.

[0018] The invention is based on the understanding that a low altitude of the first primary orbit results in a large proportion of the observed space objects having a higher altitude. Consequently, a low altitude leads to an upward-facing field of view, oriented away from the planetary surface. In particular, such a field of view is not tangentially oriented or directed towards the planetary surface, so that the influence of the planetary surface and / or atmosphere is reduced or eliminated.

[0019] One advantage of these orbital altitudes compared to observations from the planetary surface or even lower altitudes is that the celestial objects can be observed without interference, for example, from clouds. Another advantage is that pitch angles of ±20° allow viewing into regions of high object density.

[0020] One advantage of these orbital altitudes over higher altitudes is that observations can be made essentially free of atmospheric interference, for example, because the background brightness is low, as there is no need to look downwards towards the planet. As a result, dark space typically forms the background in images, making celestial objects stand out clearly against it. This allows even faint celestial objects to be detected. Another advantage of low orbital altitudes and the resulting viewing direction away from the planetary surface is that shorter apertures can be used.

[0021] In a preferred embodiment of the satellite system, at least one, preferably two or more satellites, has a light shield. The light shield is specifically arranged and designed to reduce and / or prevent the influence of stray light on the images. It is preferred that the observation device includes the light shield.

[0022] The lens hood has, in particular, an aperture diameter and an aperture length. It is preferred that the aperture diameter be between 2 cm and 40 cm, particularly between 5 cm and 25 cm. Furthermore, it is preferred that the aperture length be between 8 cm and 200 cm, particularly between 20 cm, 40 cm, or 60 cm and 160 cm.

[0023] Furthermore, preferably the ratio of the aperture diameter to the aperture length is between 0.05 and 1.25, more preferably between 0.1 and 0.5, and even more preferably between 0.1 and 0.35. Such a stray light baffle enables optimal observation from a satellite in a low first principal orbit.

[0024] The monitoring and / or detection of space objects can be carried out directly or indirectly. For example, direct monitoring and / or detection of space objects can be enabled by means of a suitably designed control device. Furthermore, the monitoring and / or detection of space objects can be carried out indirectly, for example, by the satellite system generating and providing the necessary data to a centralized control system.

[0025] The control device described above and below can be arranged and configured to perform the described functions individually or in combination. Furthermore, the satellite system can have two or more control devices arranged and configured to perform the aforementioned functions. The control device can be located on one, two, or more of the satellites. It may be preferred that each satellite has a control device. It may also be preferred that the control device be located on an additional control satellite, which communicates with the satellites containing the observation device. Furthermore, the control device can be located on the surface of the orbited celestial body. Additionally, the control device can be located on another natural and / or artificial object in space.

[0026] The satellite system comprises satellites arranged in at least one primary orbit. The satellite system particularly comprises two or more, and especially a plurality, of satellites. For example, the satellite system may have between 6 and 25 satellites. The satellites may be identical or different in design. The satellites are particularly arranged and configured to be placed in the at least one primary orbit. Preferably, the satellites are distributed substantially equidistantly along the primary orbit. Furthermore, it is preferred that the primary orbit is polar. Polar can, for example, mean that the primary orbit has an inclination between 60° and 120°, particularly between 85° and 115°, preferably between 90° and 110°, with respect to the equatorial plane.

[0027] The satellites can also be arranged in more than one primary orbit. For example, the satellites can be arranged in two or more primary orbits. The two or more primary orbits can differ, for example, in their orbital altitudes, and thus in their distance from the planetary surface. Furthermore, the two or more primary orbits can differ in their inclination, in particular by less than 10°, preferably less than 5°, and particularly less than 3°. Furthermore, the two or more primary orbits can differ in their ascending node local time; for example, one primary orbit can have an ascending node local time of 06:00 and another primary orbit can have an ascending node local time of 06:30 or 05:30.

[0028] The first principal orbit, or the two or more first principal orbits, are defined in particular around a celestial body, especially a planet, for example the Earth.

[0029] The satellites of the satellite system are equipped with an observation device. The observation device may, for example, include a telescope unit. Furthermore, the observation device may include a sensor, in particular an optical sensor and / or an infrared sensor. Additionally, the observation device may include a radar unit. The observation device is arranged and configured to generate images of space objects within an observation field. The observation device is preferably arranged and configured to generate the images by controlling an imaging sensor.

[0030] The field of view can, for example, be the field of view of a telescope-sensor unit. The images of the space objects can be generated by the observation device, in particular by focusing on the space object and accordingly mapping this magnified image onto a sensor pixel or onto a multitude of sensor pixels.

[0031] It is intended that at least one primary orbit will have an altitude between 200 km and 800 km, so that celestial objects to be observed are preferably located at the same or a higher altitude, in order to orient the field of view away from the celestial body. Such low primary orbits are not usually planned, as, among other things, more extensive correction measures are required to operate the satellites at such a low altitude.

[0032] In space-based observation of space debris, such low orbital altitudes offer the advantage that most space debris is located at higher altitudes, allowing the observation device to look upwards, away from the celestial body. This avoids looking into the body's atmosphere or at its surface, resulting in higher observation quality. In particular, the signal-to-noise ratio can be improved. Furthermore, less stray light is captured by the observation device, allowing for a shorter stray light baffle. This, in turn, enables more compact satellites, reducing the effort required for launching them from the surface. Additionally, more compact satellites are easier to operate at low orbital altitudes because they have less drag.Furthermore, the complexity and therefore the cost of the satellites is reduced, as a fixed, rather than a retractable, stray light shield can be used.

[0033] The orbital altitude refers specifically to the distance of at least one primary orbit from the surface of the celestial body. This distance is, in particular, the length of a straight line extending from the celestial body to the primary orbit, perpendicular to the surface of the celestial body. Alternatively, the distance can be the shortest line connecting the surface of the celestial body to the primary orbit.

[0034] The orbital altitude can also be defined as an orbital altitude span, for example, to describe the orbital altitudes along an elliptically shaped first principal orbit. The first principal orbit can be eccentric.

[0035] A preferred embodiment of the satellite system provides that the at least one first principal orbit has a lower altitude limit of 200 km, preferably 250 km, more preferably 300 km, and / or more preferably 350 km. A further preferred embodiment of the satellite system provides that the at least one first principal orbit has an upper altitude limit of 800 km, preferably 750 km, more preferably 700 km, more preferably 650 km, more preferably 600 km, more preferably 550 km, more preferably 500 km, and / or more preferably 450 km.

[0036] Based on the altitude limits mentioned above, the altitude of the at least one first main orbit can be, for example, between 200 km and 750 km, between 200 km and 450 km, between 350 km and 800 km, or between 350 km and 450 km. It is preferred that the altitude remains essentially constant during normal operation, for example, at 400 km. Due to physical effects, such as gravity and drag, the altitude will fluctuate within certain limits.

[0037] A preferred embodiment of the satellite system provides that the satellites are arranged in two or more primary orbits and that at least two of the two or more primary orbits differ in orbital altitude.

[0038] It is preferred that the altitudes of the two or more first main orbits have a difference of between 5 km and 200 km, particularly between 50 km and 200 km, preferably less than 200 km, further preferably less than 150 km, further preferably less than 100 km, and further preferably less than 50 km. It is also preferred that the difference be more than 10 km, more than 20 km, more than 50 km, more than 100 km, more than 150 km, and / or more than 200 km. The difference defines, in particular, a distance between the two or more first main orbits, and especially a minimum or maximum distance between the two or more first main orbits.

[0039] Satellites orbiting at different altitudes have the advantage of avoiding corotation between these two satellites and a space object. Orbital altitude defines the rotation period around the planet. A space object and a satellite with the same orbital altitude may never be within line of sight of each other, for example, because the satellite and the space object are orbiting the Earth on opposite sides of the planet with the same rotation period. With two satellites at different altitudes, this space object can still be observed, since at least one of these two satellites does not corotate with the space object and can therefore be used for observation.

[0040] A preferred embodiment of the satellite system provides that the satellites each have a propulsion device for altitude adjustment and / or drag compensation, which is arranged and designed to position the satellites on the at least one main orbit with an orbital altitude between 200 km and 800 km, for example with the orbital altitude limits mentioned above, in particular between 350 km and 550 km.

[0041] The drive device is preferably further arranged and configured to adjust, and in particular control, the position of the satellite. The position of the satellite is understood to mean, in particular, its alignment within a local coordinate system. For example, an optical axis of the observation device can be rigidly attached to the satellite, so that the alignment of the optical axis is effected by a change in the satellite's position.

[0042] A preferred design of the satellite system provides that at least one of the satellites is aerodynamically optimized. For example, the satellite may have an aerodynamically optimized main body. Furthermore, the satellite may have aerodynamically optimized attachments.

[0043] A preferred embodiment of the satellite system provides that at least one of the satellites is configured with at least one CubeSat and preferably has a size of less than 32 U, 27 U, 24 U, 18 U and / or 16 U. U is a unit of measurement for CubeSats, where 1 U defines a usable volume of 10 cm x 10 cm x 10 cm.

[0044] CubeSat is a specification used for cost-effective small satellites that has become an industry standard. With a size of less than 32U, the satellite has low drag, thus requiring fewer corrections from the propulsion system.

[0045] A preferred embodiment of the satellite system provides that it includes a control device which is arranged and configured to set a pitch angle between the first principal orbit and an optical axis of the observation device.

[0046] The optical axis can refer, for example, to a line of symmetry of the field of view, even if it is not an optical observation device. In the case of a telescope, this could be the line of symmetry of the field of view. To adjust the pitch angle, the control device can, for example, control the drive device and / or the observation device.

[0047] By adjusting the pitch angle in this way, the observation field can be directed towards regions of high object density while simultaneously enabling a favorable solar phase angle and / or contrast, thus optimizing the detectable field of view passages. The uniformity of the movement allows for advantageous exposure during this process, enabling the extraction of precise measurements.

[0048] A preferred embodiment of the satellite system provides that the control device is arranged and configured to adjust the pitch angle between -20° and +20°. In particular, it is preferred that the control device is arranged and configured to adjust the pitch angle between 0° and 20° in order to reduce the influence of the celestial body.

[0049] It is preferred that the control device is arranged and configured to control and / or regulate the drive device in such a way that the satellite or satellites are positioned and / or are positioned on the at least one principal orbit with an orbital altitude between 200 km and 800 km.

[0050] A preferred embodiment of the satellite system provides that the control device is arranged and configured to control an imaging sensor of the observation device such that continuous streak images of space objects and stars are generated in order to obtain a large number of streak images for creating a space object position image. Due to the movement of the satellites in the curved first principal orbit and the preferably constant pitch angle between the optical axis and the first principal orbit, space objects and stars are imaged as streaks for a suitably selected first principal orbit, since there is always relative motion between the optical axis and the space objects or stars. The continuous generation of streak images of space objects and stars means, in particular, that exposures are carried out at short intervals.The invention is further based on the understanding that lines in images are easier to recognize than point-like images of stars or celestial objects. In particular, due to the large number of celestial objects and stars, a line-like image is easier to interpret than a point-like image.

[0051] Satellites controlled in this way eliminate the previous need for regular corrections or focusing during operation, thus creating a harmonious image on the basis of which space objects can be detected with a higher probability.

[0052] A preferred embodiment of the satellite system provides that it comprises a torus-shaped surveillance area extending around the celestial body. It is further preferred that the control device is arranged and configured to align the observation fields in such a way as to generate images of the space objects located within the torus-shaped surveillance area.

[0053] It is particularly preferred that the observation fields within the monitoring area can be aligned, so that their alignment in turn defines the torus-shaped monitoring area. Within the torus-shaped monitoring area, the space objects are preferably observed twice or more per orbit. Furthermore, it can be advantageous that the space objects are observed only every second, third, or subsequent orbit.

[0054] A torus-shaped monitoring area enables advantageous monitoring and detection of space objects. Among other things, the torus shape ensures that space objects cannot escape observation, as they traverse the torus twice per orbit. This double traverse, in particular, results in high observation quality, since the characteristics of an image of a twice-observed object can be evaluated. Compared to a circular monitoring area, this yields two to four times the number of detections per day. Depending on its orbit, the object is observed repeatedly at intervals of approximately 45 minutes, resulting in a comparatively high observation frequency. One advantage of this high observation frequency is that space objects can be cataloged with high orbital accuracy.Another advantage of dual observation is that two different sides of the space object can be imaged, thereby increasing the data point density.

[0055] The torus-shaped surveillance area can be defined, for example, by a bulge-shaped surface with an opening, particularly a central opening. The torus-shaped surveillance area can, for example, have the shape of a donut.

[0056] The celestial body is preferably positioned within the opening of the torus-shaped monitoring area. The torus-shaped monitoring area can have a cross-section extending orthogonally to a circle. This torus cross-section can, for example, be circular and / or elliptical. Furthermore, the torus cross-section can be rectangular, particularly with rounded corners. The torus cross-section can also be square, particularly with rounded corners. The torus can also be understood as the product of two circles. Naturally, the torus-shaped monitoring area can deviate from an ideal geometric shape of a torus; for example, the surfaces of the torus can wobble, oscillate, and / or flutter. Furthermore, the torus cross-section can be variable along its circular extent, particularly with regard to size, radius, and / or geometry.The satellite system preferably comprises at least one control device. The control device is arranged and configured to align the observation fields such that images of the space objects located within the torus-shaped surveillance area are generated. For this purpose, the control device can, for example, align the satellites themselves and / or the observation device accordingly.

[0057] In a preferred embodiment of the satellite system, the control device is arranged and configured to assign an image property to the images, whereby the object property of a space object can be determined, among other things, based on the image property.

[0058] The image property can be, for example, an image time, a system property, an image frequency (e.g., specified in frames per second), and / or an exposure time. The system property can be, for example, the position of the satellite in question, in particular its position at the image time. The position and / or the image time can be determined, for example, by means of the Global Navigation Satellite System (GNSS). The satellites preferably have a GNSS module that is arranged and configured to determine the position and / or the image time of the satellite. The image property can also be a spatial resolution of the sensor, such that, for example, information is available about the angle in the sky described by a specific pixel in order to evaluate the location of a space object and / or a star.

[0059] In a preferred embodiment of the satellite system, the control device is arranged and configured to evaluate the generated images in order to determine object information, in particular an orbit and / or motion information. Furthermore, it may be preferred that the object information is determined, among other things, based on the image properties. The control device for evaluating the generated images on the one hand and for aligning the observation fields on the other hand can be configured as an integral or distributed system. For example, the alignment of the observation fields can be performed by a first control device of the control system, and the evaluation of the generated images can be performed by a second control device of the control system.In a further preferred embodiment of the satellite system, the at least one primary orbit is oriented such that the local time of the ascending node of the primary orbit is 06:00. The primary orbit is preferably sun-synchronous. In particular, it is a sun-synchronous orbit. The observation conditions for the observation device are advantageous when the local time of the ascending node of the primary orbit is 06:00. This is due, among other things, to the fact that the observation device and the space objects are rarely or never in the Earth's shadow. Furthermore, with the forward and backward pointing capability, which will be explained in more detail below, it is possible to continuously adjust a solar phase angle of α = 90°.Furthermore, a change in the satellites' position is usually unnecessary or only required to a minor extent, as a continuous power supply is ensured because the satellites can convert solar energy into electrical energy. The fact that the local time of the ascending node of the first principal orbit is 06:00 also means that slight deviations from 06:00 local time are possible. For example, the local time of the ascending node could be between 05:30 and 06:30.

[0060] A preferred embodiment of the satellite system is characterized by the fact that it comprises two or more primary orbits, wherein the local times of the ascending nodes of the two or more primary orbits are offset from each other, so that a single space object is observed from different perspectives by satellites in different primary orbits.

[0061] For example, two first principal orbits can be defined, with the local time of the ascending node of one of the first principal orbits being 06:00 and the second principal orbit having a local time of the ascending node of 08:00. Furthermore, the local time of the ascending node of one of the principal orbits can be 05:00 and the local time of the ascending node of another principal orbit can be 07:00. It is particularly preferred that the local times of the ascending nodes are offset from each other by between 0 and 3 hours, more specifically between 0 and 2 hours, and further preferably between 1 and 2 hours. This can result, for example, in observation angles between 0° and 30°.

[0062] In a further preferred embodiment, the satellite system includes at least one additional satellite arranged in a second principal orbit, wherein the ascending node of the second principal orbit is offset from the ascending node of the first principal orbit by a predefined time interval, in particular between 0.5 hours and 6 hours, preferably between one hour and 4 hours, so that the space objects can be observed from at least two different perspectives.

[0063] In a further preferred embodiment of the satellite system, it is provided that it includes at least one additional satellite arranged in a third principal orbit, wherein the ascending node of the third principal orbit is offset from the ascending node of the first principal orbit by between 6 and 18 hours, preferably between 10 and 14 hours, for example 12 hours, such that the space objects can be observed from at least two different perspectives. This larger offset between the ascending nodes of the first and second principal orbits results in different perspectives on a space object being observed. Although the observation perspective of the second and third principal orbits may not be optimal, this can be compensated for by the advantage of the second perspective.

[0064] In another preferred embodiment of the satellite system, it is provided that at least one first principal orbit, the second principal orbit and / or the third principal orbit are aligned synchronously with the sun.

[0065] In a further preferred embodiment of the satellite system, the observation device comprises a telescope unit and at least one sensor that interacts with the telescope unit. The observation device and / or the control device may include a processor, memory (in particular non-volatile memory), a communication unit, and other data processing units and / or elements.

[0066] In a further preferred embodiment of the satellite system, at least one, preferably two or more, satellites, in particular the satellites themselves, are provided with swiveling observation fields. These observation fields can be swiveled, for example, about a pitch axis and / or a yaw axis. It is particularly preferred that the observation fields be swiveled forwards and backwards in the direction of flight of the satellites. An advantage of this embodiment is that forward and backward pointing are adjustable.

[0067] In a further preferred embodiment of the satellite system, a distance exists between two adjacent satellites such that their observation fields do not overlap. Furthermore, it may be preferred that the observation fields of two adjacent satellites are designed and / or arranged in such a way that they do not overlap. It is particularly preferred that the observation fields of two adjacent satellites are adjacent to each other or can be adjacent to each other. By arranging observation fields without overlap, a monitoring volume can be maximized at any given time.

[0068] In another preferred embodiment of the satellite system, at least two observation fields of satellites, particularly of neighboring satellites, are provided for to overlap. This allows for a high level of monitoring quality, as space objects can be observed continuously from two perspectives and / or over a longer period of time.

[0069] In a further preferred embodiment of the satellite system, two, three, or more satellites arranged in a cluster on a primary orbit are configured to form a cluster. A cluster arrangement means, in particular, that the satellites are not equidistantly distributed on the primary orbit. This allows for more dense monitoring of a section of the torus-shaped surveillance area. In a further preferred embodiment of the satellite system, at least one of the satellites includes a transmitting unit configured to send data to a receiver, in particular a ground station and / or another satellite. The data can, for example, represent images or the images being analyzed.

[0070] According to a further aspect, the aforementioned problem is solved by a computer-implemented method for monitoring and detecting space objects in near-celestial space, in particular for monitoring and detecting space debris, preferably for determining at least one property of the space objects, preferably for controlling a satellite system according to one of the embodiments described above, comprising the steps of: controlling positioning units of satellites such that the satellites are arranged on at least one first principal orbit around a celestial body, wherein the at least one first principal orbit has an altitude between 200 km and 800 km, so that the space objects to be observed are at the same or a greater altitude in order to orient the field of observation away from the celestial body.Generating images of space objects within the satellites' fields of view. It is preferred that the method includes the further step of storing the images in a satellite memory along with acquisition information. This acquisition information could, for example, be the image properties.

[0071] In a preferred embodiment of the method, this includes the step of aligning the observation fields of the satellites in such a way that a torus-shaped surveillance area is formed around the celestial body and that space objects are detected in the torus-shaped surveillance area.

[0072] The alignment of the satellites' observation fields can be achieved either by swiveling an observation device or by changing the satellite's position. By generating images within the observation fields, which in turn monitor the torus-shaped surveillance area, space objects within this area can be monitored and detected.

[0073] In a preferred embodiment of the method, this includes the step of evaluating the generated images to obtain object information, in particular an orbit and / or motion information. Evaluating the generated images can, for example, involve determining the position of the streak at a specific time and / or analyzing the streak length or the background stars, particularly by comparison with star catalogs.

[0074] According to another aspect, the aforementioned task is solved by using images for the detection of space objects obtained by a method according to one of the previously described implementation variants and / or with a satellite system according to one of the previously described implementation variants, in particular for determining at least one object property of the space objects.

[0075] A system for data processing, in particular a control device, comprising means for carrying out the steps of the procedure according to one of the implementation variants described above.

[0076] According to another aspect, the aforementioned task is solved by a computer program comprising instructions which, when the program is executed by a computer, cause it to perform the steps of the procedure according to one of the execution variants described above.

[0077] According to another aspect, the aforementioned task is solved by a computer-readable medium comprising instructions which, when executed by a computer, cause it to perform the steps of the procedure according to one of the execution variants described above.

[0078] For further advantages, design variants, and design details of the individual aspects and their possible further developments, please also refer to the descriptions of the other aspects, their corresponding features, and further developments. Preferred embodiments are explained by way of example with reference to the accompanying figures. These show:

[0079] Figure 1: a schematic, two-dimensional view of a

[0080] Satellite system;

[0081] Figure 2: a schematic, two-dimensional view of a

[0082] Satellite system;

[0083] Figure 3: a schematic, two-dimensional view of the satellite system shown in Figure 1;

[0084] Figure 4: a schematic, two-dimensional view of an exemplary

[0085] Design of a satellite system;

[0086] Figure 5: a schematic, two-dimensional view of an exemplary

[0087] Design of a satellite system;

[0088] Figure 6: a schematic, two-dimensional view of an exemplary

[0089] Design of a satellite system;

[0090] Figure 7: a schematic, two-dimensional view of an exemplary

[0091] Design of a satellite system;

[0092] Figure 8: a schematic, two-dimensional view of an exemplary

[0093] Design of a satellite system;

[0094] Figure 9: a schematic, two-dimensional view of an exemplary

[0095] Design of a satellite system;

[0096] Figure 10: a schematic, two-dimensional view of an exemplary

[0097] Design of a satellite system;

[0098] Figure 11: a schematic, two-dimensional view of an exemplary

[0099] Design of a satellite system;

[0100] Figure 12: a schematic, two-dimensional view of an exemplary

[0101] Design of a satellite system;

[0102] Figure 13: a schematic, two-dimensional view of an exemplary

[0103] embodiment of a satellite system; Figure 14: a schematic, three-dimensional view of an exemplary

[0104] Design of a satellite;

[0105] Figure 15: a schematic view of an exemplary procedure.

[0106] In the figures, identical or essentially functionally equivalent or similar elements are designated with the same reference symbols.

[0107] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another. Each of these features further develops the invention independently and can be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

[0108] Figure 1 shows a schematic, two-dimensional view of a satellite system 100 located in the vicinity of planet 106. The satellite system 100 comprises a number of satellites 108, 110, 112, and 114 arranged in two primary orbits 104 and 180. The primary orbit 104 has an altitude 178 of, for example, 400 km. The secondary primary orbit 180 has an altitude 182 of, for example, 350 km. Due to these low altitudes 178 and 182, the observation fields, shown here using the example of observation field 114b of satellite 114, are oriented upwards and away from planet 106, since space debris 102 orbits planet 106 at higher altitudes.

[0109] Figures 2 and 3 show a satellite system 100 designed for monitoring and detecting space debris 102. Satellites 108, 110, 112, and 114 are arranged in a first primary orbit 104 around a planet 106. The satellite system 100 also includes a torus-shaped monitoring area 116 extending around the planet 106. The torus-shaped monitoring area 116 is defined by the observation fields 108b, 110b, 112b, and 114b of satellites 108, 110, 112, and 114, which are described in more detail below. Figure 3 shows the satellite system 100 shown in Figure 2 from the sectional perspective AA indicated in Figure 2. The view in Figure 3 is rotated 90° relative to the view shown in Figure 2.

[0110] The torus-shaped monitoring area 116 has an annular, tubular volume. Figure 3 shows that a torus cross-section of the monitoring area 116 is circular. The torus-shaped monitoring area 116 has an outer boundary 118 and an inner boundary 120. The outer boundary 118 can be understood as the outer radius of the annular cross-section. The inner boundary 120 can be understood as the inner radius.

[0111] Furthermore, the torus-shaped monitoring area 116 extends from the first end face 122 to the second end face 124. Figure 3 also shows that, considering the positions of the North Pole 126 and the South Pole 128, the torus-shaped monitoring area 116 and the first main orbit 104 have an inclination, which can be, for example, 98°. In particular, in this exemplary embodiment, the torus-shaped monitoring area 116 is not located essentially directly above the North Pole 126 and the South Pole 128.

[0112] Figure 4 shows an exemplary arrangement of a satellite 108 in the first principal orbit 104. The satellite 108 includes the observation device 130, which is arranged and configured to produce images of space objects 102 within an observation field 108b and to image space objects 102 within the torus-shaped monitoring area 116. The observation device 130 has an optical axis 134 around which the observation field 108b is formed. The so-called limb angle 138 is established between the optical axis 134 and a tangent 136 directed towards the Earth's surface. It is important that the limb angle 138 is set above a predefined value so that the optical axis 134 is oriented away from the planetary surface to produce high-quality images of space debris 102.

[0113] Figure 5 shows that satellites 108, 110, 112, and 114 are evenly distributed along the first main orbit 104. The main orbit 104 is oriented such that satellites 108, 110, 112, and 114 move over or near the North Pole 126 and the South Pole 128. In this main orbit 104, satellites 108, 110, 112, and 114 also cross the equator 140 at certain times. Since the density of space debris over the North Pole 126 is comparatively high, it is provided that two satellites, 108 and 110, nearly meet over the North Pole 126, and that the observation fields 108b and 110b are aligned towards each other. The movement directions 108a and 110a, which are also oriented towards each other, enable corresponding monitoring of the area above the North Pole 126. The observation fields 112b and 114b of satellites 112 and 114 are oriented away from the South Pole 128.Three-quarters of an orbit later, the observation fields 112b and 114b also overlap over the South Pole 128, so that this region with high object density is also well imaged.

[0114] Figure 6 shows that satellites 108 and 114 are arranged as a first group, and satellites 110 and 112 as a second group. The distance between these groups is many times greater than the distance between satellites 108, 110, 112, and 114 within each group. The observation fields 108b and 114b, as well as the observation fields 110b and 112b of satellites 108, 110, 112, and 114, overlap continuously. As a result, while the number of observations of different space objects is not maximized, the observed space objects can be viewed simultaneously from two different perspectives, specifically with a 180° offset.

[0115] Figure 7 shows that satellites 108, 114, and 112 are arranged as a single group in the first principal orbit 104, with satellites 108, 114, and 112 moving around planet 106 in the same direction of motion 108a, 114a, and 112a. The observation fields 108b, 114b, and 112b are essentially aligned without overlap, thus maximizing the number of different space objects observed.

[0116] Figure 8 shows a similar arrangement to that shown in Figure 7, however, observation fields 108b and 114b overlap, so that the

[0117] The observation density in this area is increased. Figure 9 shows that the first principal orbit 104 is oriented such that the local time 148 of the ascending node is 06:00. The direction of the sun 142 is coming from the right.

[0118] Figure 10 shows a second primary orbit 150. The first primary orbit 104 still has a local time 148 at the ascending node of 06:00. The local time 152 at the ascending node of the second primary orbit 150 is 08:00. The local times 148, 152 of the ascending nodes of the two primary orbits 104, 150 are therefore offset from each other, so that a single space object 102 is observed from different perspectives by satellites 108, 114 with different primary orbits 104, 150. The primary orbits are shown schematically here and in the other drawings. An inclination of approximately 98° may be particularly advantageous.

[0119] Figure 11 shows a similar satellite system 100, but the first main orbit 104 has a local time 156 of the ascending node of 05:00 and the second main orbit 150 has a local time 154 of the ascending node of 07:00.

[0120] The advantage of the satellite systems 100 shown in Figures 10 and 11 lies in the observation of space objects from slightly different perspectives under near-optimal observation conditions. Observation from these different perspectives has a beneficial effect on orbital accuracy, object characterization, and the determination of the rotation state.

[0121] Figures 12 and 13 show, in addition to the first main orbit 104 with a local time 148 of the ascending node of 06:00, a third main orbit 151 with a local time 158 of the ascending node of 12:00. With such a third main orbit 151, the space objects 102 are observed from different perspectives.

[0122] Figure 14 shows a satellite 160. The satellite 160 has a base body 162 on which the other devices, units, and elements can be arranged. The base body can, for example, be a CubeSat 184. The satellite 160 has an observation device 164, which is arranged and configured to generate images of space objects within an observation field and to observe space objects within the torus-shaped monitoring area 116. Furthermore, the satellite 160 includes a control device 166, which is arranged and configured to align the observation fields 108b, 110b, 112b, 114b such that images of the space objects 102 located in the torus-shaped monitoring area 116 are generated. The satellite 160 also includes a sensor unit 168 and a propulsion device 170.Satellite 160 also includes solar panels 172, 174, which are arranged and designed to supply the satellite with electrical energy.

[0123] Figure 15 shows a computer-implemented method for monitoring and detecting space objects 102 in near-celestial space, in particular for monitoring and detecting space debris, preferably for determining at least one property of the space objects 102. The method comprises step 200: controlling positioning units 170 of the satellites 108, 110, 112, 114, 160 such that the satellites are arranged on at least one first principal orbit 104 around a celestial body 106.

[0124] Step 202 involves aligning observation fields 108b, 110b, 112b, 114b of satellites 108, 110, 112, 114, 160 such that a torus-shaped surveillance area 116 extending around the celestial body 106 is formed and that space objects 102 are detected within the torus-shaped surveillance area 116. In step 204, images of space objects 102 within the observation fields 108b, 110b, 112b, 114b are generated.

[0125] In step 206, the generated images are evaluated to obtain object information, in particular an orbit or motion information.

[0126] The satellite system 100 described above and the corresponding procedure have the advantage that space objects 102 can be observed and detected more effectively. This is made possible in particular by the low orbital altitudes, which orient the observation fields 108b, 110b, 112b, 114b of satellites 108, 110, 112, 114, 160 away from planet 106. As a result, the observation frequency is advantageously increased. The orbits of space objects, especially space debris 102, can be cataloged with greater accuracy, making object information about space debris 102 more readily available, thus making this information available to the

[0127] The operation of space objects can be better utilized.

[0128] REFERENCE MARK

[0129] 100 satellite systems

[0130] 102 Space Debris

[0131] 104 first main orbit

[0132] 106 Planet

[0133] 108 satellites

[0134] 108a Direction of movement

[0135] 108b Observation field

[0136] 110 satellites

[0137] 110a Direction of movement

[0138] 110b Observation field

[0139] 112 satellites

[0140] 112a Direction of movement

[0141] 112b Observation field

[0142] 114 satellites

[0143] 114a Direction of movement

[0144] 114b Observation field

[0145] 116 torus-shaped surveillance area

[0146] 118 outer boundary

[0147] 120 inner limit

[0148] 122 first front

[0149] 124 second front

[0150] 126 North Pole

[0151] 128 South Pole 130 Observation device

[0152] 134 optical axis

[0153] 136 Tangent

[0154] 138 Limb angle

[0155] 140 Equator

[0156] 142 Direction of the sun

[0157] 144 day page

[0158] 146 Night side

[0159] 148 LTAN = 6:00h

[0160] 150 second main orbit

[0161] 151 third main orbit

[0162] 152 LTAN = 8:00h

[0163] 154 LTAN = 7:00h

[0164] 156 LTAN = 5:00h

[0165] 158 LTAN = 12:00h

[0166] 160 satellites

[0167] 162 basic bodies

[0168] 164 Observation device

[0169] 166 Control device

[0170] 168 Sensor unit

[0171] 170 Drive device

[0172] 172 solar panels

[0173] 174 solar panels

[0174] 176 Pitch angle 178 Track height

[0175] 180 more first main orbit

[0176] 182 track height

[0177] 184 Cubesat 188 Transmitter Unit

Claims

REQUIREMENTS 1. Satellite system (100) for monitoring and detecting space objects (102) in near-celestial space, in particular for monitoring and detecting space debris, preferably for determining at least one property of the space objects (102), comprising satellites (108, 110, 112, 114, 160) arranged on at least one first principal orbit (104), - wherein each of the satellites (108, 110, 112, 114, 160) has an observation device (130, 164) which is arranged and configured to produce images of space objects (102) within an observation field (108b, 110b, 112b, 114b), - wherein the at least one first principal orbit (104) has an orbital altitude (178, 182) between 200 km and 800 km, so that space objects (102) to be observed are preferably located at the same or greater orbital altitude (178, 182) in order to orient the observation field (108b, 110b, 112b, 114b) away from the celestial body (106).

2. Satellite system (100) according to claim 1, wherein the at least one first principal orbit (104) has a lower orbital altitude limit of 250 km, preferably of 350 km, and an upper orbital altitude limit of 650 km, preferably of 550 km and / or 450 km.

3. Satellite system (100) according to one of the preceding claims, wherein the satellites (108, 110, 112, 114, 160) are arranged on two or more first principal orbits (104, 180) and at least two of the two or more first principal orbits (104, 180) differ with respect to the orbital altitude (178, 182).

4. Satellite system (100) according to one of the preceding claims, wherein the satellites (108, 110, 112, 114, 160) each have a drive device (170) for altitude adjustment and / or drag compensation, which is arranged and configured to position the satellites (108, 110, 112, 114, 160) on the at least one main orbit (104) with the orbital altitude (178, 182) between 200 km and 800 km, in particular between 350 km and 550 km.

5. Satellite system (100) according to any one of the preceding claims, wherein - at least one of the satellites (108, 110, 112, 114, 160) is aerodynamically optimized, in particular has an aerodynamically optimized base body (162).

6. Satellite system (100) according to any one of the preceding claims, wherein - at least one of the satellites (108, 110, 112, 114, 160) is equipped with at least one CubeSat (184) and - preferably has a size of less than 32 U.

7. Satellite system (100) according to one of the preceding claims, comprising a control device (166) which is arranged and configured to set a pitch angle (176) between the first principal orbit (104) and an optical axis (134) of the observation device (130, 164).

8. Satellite system (100) according to one of the preceding claims, wherein the control device (166) is arranged and configured to adjust the pitch angle (176) between 0° and 20° in order to reduce the influence of the celestial body (106).

9. Satellite system (100) according to one of the preceding claims, wherein the control device (166) is arranged and configured to control an imaging sensor of the observation device (130, 164) in such a way that continuous line-shaped images of space objects (102) and stars are generated in order to obtain a plurality of line-shaped images for generating a space object position image.

10. Satellite system (100) according to one of the preceding claims, wherein the control device (166) is arranged and configured to assign an image property to the images, wherein the object property of a space object (102) can be determined, among other things, based on the image property.

11. Satellite system (100) according to one of the preceding claims, wherein the control device (166) is arranged and configured to evaluate the generated images in order to determine object information, in particular an orbit and / or motion information.

12. Satellite system (100) according to one of the preceding claims, wherein the at least one first principal orbit (104) is oriented such that the local time of the ascending node of the first principal orbit (104) is 6:00 a.m.

13. Satellite system (100) according to any one of the preceding claims, comprising - two or more first main orbits (104), - wherein the local times of the ascending nodes of the two or more first principal orbits (104) are offset from each other, such that a single space object can be observed from different perspectives by satellites (108, 110, 112, 114, 160) with different first principal orbits (104).

14. Satellite system (100) according to one of the preceding claims, comprising at least one further satellite (108, 110, 112, 114, 160) arranged on a second principal orbit (150), - wherein the ascending node of the second principal orbit (150) is offset from the ascending node of the first principal orbit (104) by a predefined time interval, in particular between 0.5 hours and 6 hours, preferably between 1 hour and 4 hours, so that the space objects (102) can be observed from at least two different perspectives.

15. Satellite system (100) according to one of the preceding claims, comprising at least one further satellite (108, 110, 112, 114, 160) arranged on third principal orbit (151), - wherein the ascending node of the third principal orbit (151 ) is offset from the ascending node of the first principal orbit (104) by between 6 hours and 18 hours, preferably between 10 hours and 14 hours, so that the space objects (102) can be observed from at least two different perspectives.

16. Satellite system (100) according to one of the preceding claims, wherein the at least one first principal orbit (104), the second principal orbit (150) and / or the third principal orbit (151) are aligned synchronously with the sun.

17. Satellite system (100) according to any one of the preceding claims, wherein the orbital heights (178, 182) of at least one first main orbit (104), the second main orbit (150) and / or the third main orbit (151) are the same.

18. Satellite system (100) according to any one of the preceding claims, wherein - at least one of the satellites (108, 110, 112, 114, 160), preferably two or more, in particular the satellites (108, 110, 112, 114, 160), have swiveling observation fields (108b, 110b, 112b, 114b) and - preferably the observation fields (108b, 110b, 112b, 114b) can be swivelled forwards and backwards in the direction of movement (108a, 110a, 112a, 114a).

19. Satellite system (100) according to any one of the preceding claims, wherein - between two adjacent satellites (108, 110, 112, 114, 160) there is such a distance that the observation fields (108b, 110b, 112b, 114b) of these satellites (108, 110, 112, 114, 160) are non-overlapping and / or the observation fields (108b, 110b, 112b, 114b) of two adjacent satellites (108, 110, 112, 114, 160) are designed and / or can be arranged in such a way that they are non-overlapping.

20. Computer-implemented method for monitoring and detecting space objects (102) in near-celestial space, in particular for monitoring and detecting space debris, preferably for determining at least one property of the space objects (102), comprising the steps: - Controlling positioning units of satellites (108, 110, 112, 114, 160) such that the satellites (108, 110, 112, 114, 160) are arranged on at least one first principal orbit (104) around a celestial body, wherein the at least one first principal orbit (104) has an orbital altitude (178, 182) between 200 km and has a distance of 800 km, so that the space objects to be observed (102) are at the same or greater orbital altitude (178, 182) in order to align the observation field (108b, 110b, 112b, 114b) away from the celestial body (106), Generating images of space objects (102) within the observation fields (108b, 110b, 112b, 114b) of the satellites (108, 110, 112, 114, 160).

21. Use of images for the detection of space objects (102) obtained by a method according to the preceding claim and / or with a satellite system (100) according to one of the preceding claims.

22. Data processing system, in particular control device (166), comprising means for carrying out the steps of the method according to the preceding claim.

23. Computer program comprising instructions which, when the program is executed by a computer, cause it to perform the steps of the method according to the preceding claim.

24. Computer-readable medium comprising instructions which, when executed by a computer, cause it to perform the steps of the method according to the preceding claim.

Images