Low Earth Orbit Satellite Tracking

Abstract

Methods, systems, and devices for satellite operations are described. Positioning data for the non-geostationary satellites may be received from the non-geostationary satellites via one or more satellites in an orbit higher than the orbit of the non-geostationary satellite. Based on the positioning data, trajectories of the non-geostationary satellites may be calculated. Based on the trajectories calculated for the set of non-geostationary satellites, a distance between the set of non-geostationary satellites may be predicted to fall within a threshold distance, and an alert may be communicated to one or more operators of the set of non-geostationary satellites that a distance between the set of non-geostationary satellites is predicted to fall within the threshold distance.

Description

[Technical Field]

[0001] The following generally relate to satellite operations, including satellite tracking: [Background technology]

[0002] Satellites may be located in geosynchronous equatorial orbits (which may also be referred to as geosynchronous or geostationary orbits) and non-geosynchronous equatorial orbits (which may also be referred to as non-geosynchronous orbits or non-geostationary orbits), which may be higher in position than non-geosynchronous orbits. Non-geosynchronous equatorial orbits may be deployed with more satellites than geosynchronous orbits due to, for example, lower costs of placing satellites in non-geosynchronous orbits, improved latency parameters, positioning accuracy, and mapping resolution. Due to the larger number, satellites in non-geosynchronous equatorial orbits may be at a higher risk of collision with other satellites in non-geosynchronous equatorial orbits. Summary of the Invention

[0003] The described technology relates to improved methods, systems, devices, and apparatus for supporting satellite operations. Positioning data for non-geostationary satellites may be received from the non-geostationary satellites via one or more satellites in orbits higher than the orbits of the non-geostationary satellites. Based on the positioning data, trajectories of the non-geostationary satellites may be calculated. Based on the trajectories calculated for the set of non-geostationary satellites, a distance between the set of non-geostationary satellites may be predicted to fall within a threshold distance, and an alert may be communicated to one or more operators of the set of non-geostationary satellites that a distance between the set of non-geostationary satellites is predicted to fall within the threshold distance. [Brief explanation of the drawings]

[0004] [Figure 1]FIG. 1 illustrates an example of geosynchronous equatorial orbit (GEO) and non-GEO satellites orbiting the Earth, according to embodiments described herein. [Figure 2] FIG. 2 illustrates an example of a satellite subsystem that includes one or more satellite networks, where the satellite subsystem supports tracking of low earth orbit satellites according to embodiments described herein. [Figure 3] FIG. 3 illustrates an example of a collision detection system that supports tracking of low earth orbit satellites, according to embodiments described herein. [Figure 4] FIG. 4 illustrates an example of a non-GEO satellite system that supports tracking of low earth orbit satellites, according to embodiments described herein. [Figure 5] FIG. 5 illustrates an example ground station that supports tracking of low earth orbit satellites according to embodiments described herein. [Figure 6] FIG. 6 illustrates an example sequence of operations for tracking low earth orbit satellites according to embodiments described herein. [Figure 7] FIG. 7 illustrates an example sequence of operations for tracking low earth orbit satellites according to embodiments described herein. [Figure 8] FIG. 8 illustrates an example sequence of operations for tracking low earth orbit satellites according to embodiments described herein. [Figure 9] FIG. 9 shows a flowchart illustrating a method for supporting tracking of low earth orbit satellites according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0005] Satellites may be launched into geosynchronous equatorial orbits (GEO) and non-geosynchronous equatorial orbits (non-GEO). In some examples, a large number (e.g., tens of thousands) of satellites may be deployed in non-GEO, and techniques for identifying potential near misses or collisions between satellites deployed in non-GEO may be used to prevent collisions between the satellites. To identify potential near misses or collisions, ground stations may use radar to measure the positions of various space objects, including non-GEO satellites. The positions of various space objects measured by different tracking stations may be used to predict the trajectories of the various space objects.

[0006] While ground-based radar technology can accurately determine the current location of a space object, its ability to continuously track the trajectory of a space object may be limited. For example, a ground system used to determine the location of a space object may include a small number of ground stations (e.g., several dozen ground stations). Therefore, the amount of measurements obtained by the ground system for a particular space object may be limited, e.g., fewer than 10 measurements may be obtained for the space object over a single orbital period. Because the ground system may use a limited set of measurements and orbit prediction techniques to predict portions of the trajectory located between ground stations, perturbations in the space object's orbit that occur between ground stations may be overlooked. Additionally, given recent plans to deploy large satellite constellations into non-GEO orbits, the ability to generate real-time information regarding the orbits of non-GEO satellites may become increasingly important because, for example, near misses and collisions between non-GEO satellites may become more likely.

[0007] To nearly continuously track non-GEO satellites in a non-GEO system, a set of GEO satellites can be used to track the orbits of the non-GEO satellites. In some examples, the GEO satellites may be communications satellites, broadband satellites, data satellites, or satellites dedicated to collision detection between non-GEO satellites. As described herein, each GEO satellite can maintain nearly continuous contact with a non-GEO satellite within the coverage area of ​​the GEO satellite. In some examples, a large number of deployed non-GEO satellites may be within the coverage area of ​​the GEO satellite at any one time; for example, approximately 20 percent of the deployed non-GEO satellites may be within the coverage area of ​​the GEO satellite at any one time. Thus, a small number of GEO satellites (e.g., fewer than five) may be in constant contact with a majority (e.g., more than 90 percent) of the deployed non-GEO satellites. Thus, the set of GEO satellites can be used to receive near real-time positioning data (or at least an increased amount of positioning data compared to ground-based techniques) for a majority of the deployed non-GEO satellites and relay it to one or more ground stations.

[0008] In some examples, positioning data for the non-GEO satellites may be acquired at one or more ground stations via a set of GEO satellites. That is, the set of GEO satellites may be used to relay positioning data received from the non-GEO satellites to one or more ground stations. Trajectories of the non-GEO satellites may be calculated (e.g., at the ground station) based on the acquired positioning data. Based on the trajectory calculations, one or more predictions may be obtained that the set of one or more non-GEO satellites may fall within a threshold distance of each other. One prediction may indicate that the first non-GEO satellite will fall within a threshold distance (e.g., within 1000 meters) of the second non-GEO satellite based on a first trajectory calculated for a first non-GEO satellite and a second trajectory calculated for a second non-GEO satellite. An alert that the distance between the first non-GEO satellite and the second non-GEO satellite is predicted to be less than the threshold distance may be communicated to operators of the first non-GEO satellite and the second non-GEO satellite, for example.

[0009] The use of GEO satellites to monitor the orbits of non-GEO satellites on a near-continuous basis allows the trajectory of the non-GEO satellites to be determined with greater accuracy, improving the ability to detect near misses and / or potential collisions compared to using terrestrial systems. Additionally, the use of near-continuous monitoring of non-GEO satellites allows real-time and accurate warnings to be sent to the satellite operators informing them of detected near misses and potential collisions, thereby enabling the non-GEO satellite operators to take action earlier than using terrestrial systems.

[0010] FIG. 1 illustrates an example of GEO and non-GEO satellites orbiting the Earth, according to embodiments described herein.

[0011] Constellation diagram 100 may show a set of GEO satellites 105 in geosynchronous equatorial orbits 120, and non-GEO satellites 115 that orbit the Earth in orbits closer to the Earth than the geosynchronous equatorial orbits 120, such as non-geosynchronous equatorial orbits.

[0012] Satellites may be launched into different orbits, such as GEO or non-GEO. Satellites in GEO may be referred to as GEO satellites 105. Satellites in non-GEO may be referred to as non-GEO satellites 115 (or may be referred to as non-geostationary satellites). Non-GEO includes medium Earth orbit (MEO), low Earth orbit (LEO), and equatorial low Earth orbit (ELEO). Satellites in MEO may be referred to as MEO satellites, and satellites in LEO may be referred to as LEO satellites, etc. GEO satellites 105 may orbit the Earth at a speed that matches the rotational speed of the Earth, allowing the GEO satellites 105 to remain in a single position relative to a point on the Earth throughout the GEO. LEO satellites may orbit the Earth at a speed (e.g., relative to the ground) that exceeds the rotational speed of the Earth, allowing the position of the LEO satellite relative to a point on the Earth to change as the LEO satellite moves throughout the LEO. LEO satellites can be launched with low inclination (e.g., ELEO) or high inclination (e.g., polar orbit) to provide different types of coverage and revisit times for a given region of the Earth. MEO satellites may orbit the Earth at speeds that exceed the Earth's rotational speed, but may also be at higher altitudes than LEO satellites. Highly elliptical orbit (HEO) satellites can orbit the Earth in an elliptical pattern, with the satellite moving closer to and further away from the Earth throughout the HEO.

[0013] In some examples, GEO satellites 105 may cover a large geographic area (e.g., approximately one-third of the Earth's surface) compared to the geographic area covered by non-GEO satellites 115. For example, a first GEO satellite 105-1 may cover an area of ​​the Earth within a first coverage area 110-1. In some examples, a small number of GEO satellites 105 (e.g., fewer than five) may cover a significant portion of the Earth's surface (e.g., greater than 90%). A GEO satellite 105 may also relay signals from a large number of non-GEO satellites 115 (e.g., thousands, tens of thousands, or hundreds of thousands) within the coverage area 110 of the GEO satellite 105. Similarly, a small number of GEO satellites 105 may be used to continuously relay signals to a significant portion (e.g., greater than 90%) of the non-GEO satellites 115 deployed in non-GEO orbits.

[0014] GEO satellites 105 may be more complex and expensive than non-GEO satellites 115. Furthermore, launching GEO satellites 105 into orbit may be more costly than launching non-GEO satellites 115 into orbit, and the number of orbital slots for GEO may be limited. As a result, a larger number of non-GEO satellites 115 may be deployed than GEO satellites 105. Given the large number of non-GEO satellites 115 that may be deployed in non-GEO orbits, techniques may be used to identify potential near misses or collisions between non-GEO satellites. One technique for identifying potential near misses or collisions may include using tracking stations on the Earth's surface. Ground-based tracking stations may use radar-based technology to measure the positions of various space objects, including non-GEO satellites 115. The positions measured by various ground-based tracking stations may be used to predict the trajectories of various space objects.

[0015] While ground-based radar technology can accurately determine the current location of a space object, its ability to continuously track the orbit of a space object may be limited. For example, a ground system used to determine the location of a space object may include a small number of ground stations (e.g., several dozen ground stations). Therefore, the amount of measurements obtained by the ground system for a particular space object may be limited, e.g., fewer than 10 measurements may be obtained for the space object over an entire orbital period. Because the ground system may use a limited set of measurements and orbit prediction techniques to predict portions of the orbit that lie between ground stations, perturbations in the space object's orbit that occur between ground stations may be overlooked. Additionally, given recent plans to deploy large satellite constellations into non-GEO orbits, the ability to generate real-time information regarding the orbits of non-GEO satellites may become increasingly important because, for example, near misses and collisions between non-GEO satellites may become more likely.

[0016] To nearly continuously track non-GEO satellites 115 in a non-GEO system, a set of GEO satellites 105 can be used to track the orbits of the non-GEO satellites 115. In some examples, the GEO satellites may be communications satellites, broadband satellites, data satellites, or satellites dedicated to collision detection between non-GEO satellites. As described herein, each GEO satellite 105 can maintain nearly continuous contact with a non-GEO satellite 115 within the coverage area 110 of the GEO satellite. In some examples, a large number of deployed non-GEO satellites 115 may always be within the coverage area 110 of the GEO satellite; for example, approximately 20 percent of the deployed non-GEO satellites 115 may always be within the coverage area of ​​the GEO satellite 105. Thus, a small number of GEO satellites 105 (e.g., fewer than five) may always be in contact with a majority (e.g., more than 90 percent) of the deployed non-GEO satellites 115. Thus, the set of GEO satellites 105 can be used to receive near real-time positioning data (or at least an increased amount of positioning data compared to ground-based techniques) for a large portion of the deployed non-GEO satellites 115 and relay it to one or more ground stations.

[0017] In some examples, positioning data for the non-GEO satellites 115 may be obtained at one or more ground stations via a set of GEO satellites 105. That is, the set of GEO satellites 105 may be used to relay positioning data received from the non-GEO satellites 115 to one or more ground stations. Trajectories of the non-GEO satellites 115 may be calculated (e.g., at the ground station) based on the obtained positioning data. Based on the trajectory calculations, one or more predictions may be obtained that the set of one or more non-GEO satellites 115 may come within a threshold distance of each other. One prediction may indicate that a first non-GEO satellite 115 will come within a threshold distance (e.g., within 1000 meters) of a second non-GEO satellite 115 based on a first trajectory calculated for a first non-GEO satellite 115 and a second trajectory calculated for a second non-GEO satellite 115. A warning that the distance between the first non-GEO satellite 115 and the second non-GEO satellite 115 is predicted to be less than the threshold distance may be communicated, for example, to the operators of the first non-GEO satellite 115 and the second non-GEO satellite.

[0018] FIG. 2 illustrates an example of a satellite subsystem that includes one or more satellite networks, where the satellite subsystem supports tracking of low earth orbit satellites according to embodiments described herein.

[0019] Satellite subsystem 200 illustrates GEO satellites 205, non-GEO satellites 215, ground stations 230 (sometimes referred to as gateways), a network operations center 240, user terminals 250, one or more networks 245, one or more radar stations 260, and channels and / or connections between various networks and devices.

[0020] GEO satellite 205 and non-GEO satellite 215 may be examples of the GEO satellite and non-GEO satellite, respectively, described with reference to FIG. 1 . GEO coverage area 210 of GEO satellite 205 may include non-GEO satellite 215 and ground station 230. In some examples, GEO satellite 205 serves terminals within coverage area 210 using multiple beams, where time and frequency resources may be reused in various beams. In each beam, a set of terminals (e.g., user terminals 250) within the beam may be assigned a multiplexed set of time and frequency resources. In some examples, each beam may support multiple carriers that can schedule communications to one or more terminals. In some examples, handover procedures are used to maintain uninterrupted communications with a terminal when the terminal transitions from the coverage area of ​​one beam to the coverage area of ​​a new beam. After being handed over to a new beam, the terminal may be assigned a new set of time and frequency resources within the new beam for receiving communications.

[0021] In some examples, communication link 225 may be formed between GEO satellite 205 and non-GEO satellite 215 within GEO coverage area 210. In some examples, communication link 225 is a network-based connection established between non-GEO satellite 215 and GEO satellite 205, for example, using network management signaling. In some examples, communication link 225 is a signal path (e.g., a one-way signal path) from non-GEO satellite 215 to GEO satellite 205. Communication link 225 may be associated with the transmission of signals between GEO satellite 205 and non-GEO satellite 215. In some examples, a terminal located on non-GEO satellite 215 may include transmitter 255 and establish communication link 225 with GEO satellite 205. In some examples, to establish communication link 225, the terminal may identify itself based on transmitting subscription information via GEO satellite 205 to an operator of a satellite communications network that includes GEO satellite 205. Network operations center 240 may receive the subscription information and authenticate the terminal. Based on the authentication of the terminal, the network operations center 240 can allocate beam resources for communicating the positioning information to the non-GEO satellite 215. Additionally, a first connection 227 can be established between the GEO satellite 205 and the first ground station 230-1. In some examples, multiple connections are established between the GEO satellite 205 and multiple ground stations, including the first ground station 230-1.

[0022] The non-GEO satellites 215 may be configured to perform different functions / achieve different purposes. In some examples, one or more of the non-GEO satellites 215 (e.g., the second non-GEO satellite 215-2, the fourth non-GEO satellite 215-4, or both) may be configured for imaging, sensing, or surveillance operations. In some examples, one or more of the non-GEO satellites 215 (e.g., the first non-GEO satellite 215-1, the third non-GEO satellite 215-3, and the Mth non-GEO satellite 215-M) may be configured for communications operations. The non-GEO satellites 215 configured for communications may be used to communicate with user terminals 250 located within their respective non-GEO coverage areas 220 via user connections 217. In some examples, the non-GEO satellites 215 may communicate directly with the ground station 230 via the second connection 228. In other examples, the non-GEO satellites 215 may communicate indirectly with the ground station 230 via the GEO satellite 205. In some examples, the non-GEO satellites 215 may communicate directly with the ground stations 230 or may communicate indirectly with the ground stations 230 via the GEO satellites 205 .

[0023] One or more non-GEO satellites 215 (e.g., first non-GEO satellite 215-1 and Mth non-GEO satellite 215-M) may be in the same constellation as GEO satellite 205 (e.g., managed by the same operator and configured to achieve a common purpose). For example, GEO satellite 205, first non-GEO satellite 215-1, and Mth non-GEO satellite 215-M may be part of a communications network, where GEO satellite 205 may be used to relay communications between a ground station (e.g., first ground station 230-1), first non-GEO satellite 215-1, and Mth non-GEO satellite 215-M.

[0024] In some examples, one or more non-GEO satellites 215 (e.g., second non-GEO satellite 215-2, third non-GEO satellite 215-3) may be in a different constellation than GEO satellite 205 (e.g., managed by a different operator and configured to achieve a different purpose). For example, second non-GEO satellite 215-2 may be an imaging satellite, while GEO satellite 205 may be a communications satellite. In such a case, second non-GEO satellite 215-2 may not exchange signaling associated with its purpose (e.g., imagery signaling) with GEO satellite 205. In another example, third non-GEO satellite 215-3 may be a communications satellite managed by a different operator than GEO satellite 205. In another example, GEO satellite 205 may be a commercial broadband satellite and, for example, may communicate directly with user terminal 250 without the assistance of non-GEO satellite 215.

[0025] The first ground station 230-1 may be configured to receive signals transmitted from the GEO satellites 205, the non-GEO satellites 215, or both. The first ground station 230-1 may include an antenna 235 and a transceiver 237. In some examples, the first ground station 230-1, the GEO satellites 205, and one or more non-GEO satellites 215 (e.g., the first non-GEO satellite 215-1 and the Mth non-GEO satellite 215-M) may be included in the same satellite network. In such cases, communications between one or more networks 245 and the user terminal 250 may be communicated using the first ground station 230-1, the GEO satellites 205, and the non-GEO satellites 215, and in some examples, communications between the one or more networks 245 and the user terminal 250 may be communicated without using the GEO satellites 205. In some examples, the ground station 230 is included in a satellite communications network. In such cases, the first ground station 230-1 may be referred to as an access node terminal and may provide connectivity to one or more communications networks (e.g., a cellular network, a telephone network, or both), a data network (e.g., the Internet, a private network, or both), or both. The first ground station 230-1 may be coupled to other ground stations 230, a network operations center 240, and one or more networks 245. In some examples, the ground station 230 may be included in a collision detection network.

[0026] Network operations center 240 may be or may include at least one of a network control center, a satellite and ground station command center, or a central processing center. In some examples, network operations center 240 provides an interface between one or more networks 245 (e.g., the Internet, other public data networks, private data networks, government networks, etc.) and a satellite network including ground stations 230, GEO satellites 205, and, in some examples, one or more non-GEO satellites 215. In some examples, one or more networks 245 may be used to contact an operator 265. For example, one or more networks 245 may be connected to a command center for operator 265. Operator 265 may own and manage the operation of the various satellites included in satellite subsystem 200. For example, a first operator 265-1 may own and manage the operation of GEO satellite 205, a first non-GEO satellite 215-1, a fourth non-GEO satellite 215-4, and an Mth non-GEO satellite 215-M. An Nth operator 265-N may also own and manage the operation of a third non-GEO satellite 215-3.

[0027] Radar station 260 may be a ground station that uses radar to determine the location of a space object (e.g., a non-GEO satellite 215). Radar station 260 may be included in a radar network that includes a set of radar stations distributed across the Earth's surface, and measurements obtained by the set of radar stations may be used to calculate the trajectory of the space object. In some examples, the radar network that includes radar station 260 is a government network (e.g., North American Aerospace Defense Command (NORAD)).

[0028] As described herein, the non-GEO satellites 215 may come within a threshold distance of each other, thereby exposing the non-GEO satellites 215 to a risk of collision with each other. Also as described herein, ground-based techniques for tracking and predicting the trajectories of the non-GEO satellites 115 may collect insufficient data to accurately predict the trajectories of the non-GEO satellites 115 between measurement locations and therefore may be unable to predict / overlook perturbations in the trajectories of the non-GEO satellites 115 that may occur between measurement locations. Thus, ground-based techniques for tracking and predicting the trajectories of the non-GEO satellites 115 may miss potential collision events between the non-GEO satellites 115.

[0029] To nearly continuously track the non-GEO satellites 215 (and, in some examples, other space objects deployed on non-GEO satellites), the non-GEO satellites 215 may be configured to transmit positioning information (e.g., periodically) to the GEO satellites 205, which may be configured to forward or relay the positioning information to one or more ground stations, such as the first ground station 230-1. In some examples, each non-GEO satellite 215 may include a transmitter 255 used to transmit positioning data for the non-GEO satellite 215 coupled to the transmitter 255 to the GEO satellite 205 via communication link 225. In some examples, the transmitter 255 is included in a terminal included in the GEO satellite 205, where the terminal may have a subscription to access a first satellite communications network including the GEO satellite 205, the first non-GEO satellite 215-1, the Mth non-GEO satellite 215-M, the first ground station 230-1, and the Pth ground station 230-P. The terminal may also have a transceiver that enables it to receive and transmit communications with the satellite communications network. In some examples, one or more user terminals 250 served by one or more non-GEO satellites 215 may also have a subscription to access a first satellite communications network. In other examples, the user terminals 250 may have a subscription to access a different satellite communications network than the terminals included in the non-GEO satellites 215, where the non-GEO satellites 215 are used to serve the user terminals 250, e.g., the different satellite communications network may include a third non-GEO satellite 215-3 and a third ground station 230-3.

[0030] FIG. 3 illustrates an example of a collision detection system that supports tracking of low earth orbit satellites, according to embodiments described herein.

[0031] Collision detection system 300 illustrates, in block diagram form, a satellite subsystem including one or more satellite networks and one or more other networks that may interface with the one or more satellite networks, according to embodiments described herein.

[0032] Collision detection system 300 includes a first non-GEO satellite 315-1, a second non-GEO satellite 315-2, a space object 320, a satellite network 325, a radar system 330, a control station 335, a government agency 340, a flight information provider 345, one or more networks 350, and one or more operators 365. First non-GEO satellite 315-1 and second non-GEO satellite 315-2 may be examples of the non-GEO satellites of Figure 1 or Figure 2. Operator 365 may be an example of operator 265 of Figure 2.

[0033] Space object 320 may be a non-satellite object (e.g., a device fragment, a meteorite, etc.) Space object 320 may also be a satellite (e.g., a non-GEO satellite of FIG. 1 or FIG. 2).

[0034] Satellite network 325 may be a satellite communications network. Satellite network 325 may include one or more GEO satellites (e.g., GEO satellite 205 of FIG. 2), one or more ground stations (e.g., first ground station 230-1, second ground station 230-2, and Pth ground station 230-P of FIG. 2), a control center, a network operations center (e.g., network operations center 240 of FIG. 2), terminals (e.g., one or more user terminals 250 of FIG. 2, terminals installed on non-GEO satellites 215 of FIG. 2), or any combination thereof. In some examples, satellite network 325 may also include one or more non-GEO satellites (e.g., first non-GEO satellite 215-1 and Mth non-GEO satellite 215-M, and in some examples, one or both of first non-GEO satellite 215-1 and second non-GEO satellite 215-2). The non-GEO satellites included in satellite network 325 may perform various roles within satellite network 325, including providing communication services to user terminals 250 (e.g., via GEO satellites 205). In some cases, collection of positioning information from other non-GEO satellites in satellite network 325 or other satellite networks may be performed independently from the non-GEO satellites in satellite network 325 (e.g., positioning information may be routed directly from GEO satellites 205 without routing through the non-GEO satellites of satellite network 325).

[0035] The radar system 330 may include a network of ground radar stations (e.g., radar station 260 in FIG. 2) used to detect the positions of space objects (including the space object 320, the first non-GEO satellite 315-1, and the second non-GEO satellite 315-2).

[0036] Flight information provider 345 may provide aeronautical information such as airspace restrictions, trajectory restrictions, weather information, or any combination thereof. Flight information provider 345 may be coupled to ground stations and radars used to collect information (e.g., radar system 330).

[0037] The control station 335 may be configured to detect near misses and potential collisions between space objects. The control station 335 may further be configured to predict the trajectory of a space object based on positioning information received from the satellite network 325 and, in some examples, the radar system 330. In some examples, combining the positioning information received from the satellite network 325 with the positioning information obtained from the radar system 330 can improve the accuracy of determining the position, trajectory, or both of a space object. Additionally, the information obtained from the radar system 330 may include positioning information, trajectory information, or both of non-satellite space objects or satellites that do not transmit positioning information. The control station 335 may predict the trajectory of a non-satellite object using the information obtained from the radar system 330. In some cases, the trajectory of a satellite may be estimated by considering a probability distribution of the positioning information received from the satellite network 325 and the positioning information obtained from the radar system 330. For example, the previous positions of the satellites may be determined from the positioning information with the highest accuracy (e.g., radar system 330 may have higher accuracy for some of the satellites' positions, while positioning information from the satellites received via satellite network 325 may have higher accuracy for other of the satellites' positions). Additionally or alternatively, the probability distributions for the positioning information received from satellite network 325 and the positioning information obtained from radar system 330 may be combined to determine a joint probability distribution.

[0038] Control station 335 may also be configured to compare estimated trajectories with one another to detect near misses and potential collisions between space objects. In some examples, control station 335 can use information received from radar system 330 to detect near misses and potential collisions between non-GEO satellites and non-satellite space objects. In some examples, control station 335 can determine evasive maneuvers for one or more space objects. In some examples, aspects (or all) of control station 335 (or similarly configured components) may be included in satellite network 325, e.g., aspects of control station 335 used for predicting trajectories, detecting near misses, determining evasive maneuvers, or any combination thereof. In some examples, in addition to detecting near misses and potential collisions between space objects, control station 335 may be used to detect near misses and potential collisions between airborne objects.

[0039] In some examples, control station 335 alerts government agencies 340 of impending near misses or collisions between space objects, for example, via one or more networks 350. Networks 350 may include telephone network 352, computer network 354, cellular network 356, or combinations thereof. Computer network 354 may include wired links (e.g., coaxial cable, conductive wire, fiber optic wire) and wireless links connected to data centers and / or computer networks.

[0040] Control station 335 may also indicate proposed evasive actions for the space object. Government agency 340 may be or may include the FAA, an agency designated to manage space resources, or both. Additionally or alternatively, control station 335 may alert one or more operators 365 of an impending near miss or collision of one or more space objects owned by one or more operators 365 by sending an alert to one or more control centers 367 of the one or more operators 365.

[0041] In some examples, the control station 335 detects a near-miss or collision event between the first non-GEO satellite 315-1 and the second non-GEO satellite 315-2, for example, based on a comparison of the predicted trajectories of the first non-GEO satellite 315-1 and the second non-GEO satellite 315-2. Based on the detection of the event, the control station 335 can transmit an alert to the operator of the first non-GEO satellite 315-1 and the operator of the second non-GEO satellite 315-2, informing them that the respective non-GEO satellites are at risk of a collision. In some examples, the control station 335 also transmits proposed avoidance actions (e.g., changes in altitude or inclination) to the non-GEO satellites to avoid the collision. To determine the proposed avoidance action, the control station 335 can consider the predicted trajectories of the additional non-GEO satellites, the coverage areas of the non-GEO satellites, or both.

[0042] Based on receiving the alert, operators 365 can take action to prevent a collision. In some examples, one or both of operators 365 sends commands to each non-GEO satellite to change its course, for example, using satellite network 325 or a different network used by the operator.

[0043] In some examples, the satellite network 325 can be used to route communications between a first non-GEO satellite 315-1 and a second non-GEO satellite 315-2, for example, based on the first non-GEO satellite 315-1 and the second non-GEO satellite 315-2 entering a threshold distance of each other. In some examples, the communications include positioning data. In some examples, an impending collision between one or both of the first non-GEO satellite 315-1 or the second non-GEO satellite 315-2 can be detected (e.g., by the control station 335, the first non-GEO satellite 315-1, or the second non-GEO satellite 315-2). In such examples, an avoidance maneuver can be transmitted to the first non-GEO satellite 315-1 and the second non-GEO satellite 315-2, where one or both of the first non-GEO satellite 315-1 and the second non-GEO satellite 315-2 can automatically execute the proposed avoidance maneuver. In some examples, a non-GEO satellite taking an evasive action may notify other non-GEO satellites (via satellite network 325) of the evasive action taken so that the other non-GEO satellites can maintain their course or take complementary evasive action.

[0044] FIG. 4 illustrates an example of a non-GEO satellite system that supports tracking of low earth orbit satellites, according to embodiments described herein.

[0045] Non-GEO satellite 415 may be an example of a non-GEO satellite of Figure 1, Figure 2, or Figure 3. Non-GEO satellite 415 may be a communications satellite, an imaging satellite, a global positioning satellite, a surveillance satellite, or a combination thereof. In some examples, the function of a satellite may be referred to as a purpose, for example, the purpose of a communications satellite may be communications.

[0046] Payload 430 may be configured to support the purpose of non-GEO satellite 415. For example, if non-GEO satellite 415 is an imaging satellite (e.g., similar to third non-GEO satellite 215-3), payload 430 may include imaging equipment such as a lens, an image sensor, an aperture, etc. In another example, non-GEO satellite 415 is a communications satellite (e.g., similar to first non-GEO satellite 215-1, third non-GEO satellite 215-3, or Mth non-GEO satellite 215-M of FIG. 2), and payload 430 may include an antenna array, one or more transponders, etc.

[0047] The non-GEO satellite may also include a transceiver 425 that may be used to support operation of the payload 430. In some examples, the transceiver 425 is configured to send and receive communications using time and frequency resources assigned to an operator of the non-GEO satellite 415, protocols associated with that operator, etc. The transceiver 425 may be coupled to a first antenna 420-1 that may be configured for a first frequency band.

[0048] In some examples, the terminal 440 may be coupled to (e.g., installed on) the non-GEO satellite 415. The terminal 440 may include a positioning component 450 and a transmitter 455. The positioning component 450 may be used to track the position (e.g., Global Positioning System (GPS) coordinates), location-related information (e.g., speed, tilt, altitude, etc.) of the non-GEO satellite 415, or both. The transmitter 455 may be used to transmit the positioning information generated by the positioning component 450. In some examples, the positioning component 450 is configured to generate the positioning information periodically (e.g., every second), and the transmitter 455 is configured to periodically transmit the positioning information generated by the positioning component 450. The transmitter 455 may be configured to transmit the positioning information via a periodic set of time and frequency resources within a frequency band associated with the network of GEO satellites. In some examples, the communications manager 445 generates a message including the generated set of positioning information and periodically transmits the generated message using the transmitter 455.

[0049] In some examples, the terminal 440 may have a subscription to a satellite communications network (e.g., satellite network 325 of FIG. 3). The subscription to the satellite communications network may be a low data rate subscription (e.g., supporting data rates less than 1 Mbit / s) configured to support communication of control information supporting satellite communications, information for controlling satellite mobility functions, and positioning data. In such cases, the communications manager 445 may be configured to interface with the satellite communications network (e.g., process the control information, identify assigned resources, etc.). The transmitter 455 may also include a receiver (e.g., the transmitter 455 may be a transceiver or may be part of a transceiver). In some cases, the terminal 440 may be independent of the payload 430 and the transceiver 425. That is, the terminal 440 may be separate from the payload 430 and the transceiver 425 and may operate independently of the payload 430 (independent of the purpose of the non-GEO satellite 415). For example, the purpose of payload 430 may be configured to acquire surveillance images, but terminal 440 may not be used to communicate or access the surveillance images, i.e., the functionality of terminal 440 may be limited to identifying communication resources for transmitting positioning data.

[0050] If terminal 440 is part of a satellite communications network, terminal 440 may be similar to a user terminal, such as user terminal 250 of FIG. 2. In some examples, the satellite communications network uses a different handover technique to support handover of a terminal (such as terminal 440) between satellite beams, GEO satellites, earth stations, or combinations thereof, e.g., due to an increased velocity of a terminal such as terminal 440, than the handover technique used to support handover of a user terminal between satellite beams, GEO satellites, earth stations, or combinations thereof. In some examples, the satellite communications network may initiate handover procedures based on different thresholds for comparing communication parameters or location to beam coverage areas. For example, the beam signal power threshold for handover of a terminal on a non-GEO satellite may be higher because, e.g., the beam signal power may change more rapidly for a terminal on a non-GEO satellite such as terminal 440. In some examples, the satellite communications network may initiate handover procedures based on the location of a terminal such as terminal 440 because, unlike other terminals, the trajectory of terminal 440 is known with relative certainty. In some examples, the handover procedure is initiated when the terminal 440 comes within a threshold distance of the edge of a beam. In some examples, the threshold distance applied to handover of a terminal 440 on a non-GEO satellite may be greater than the threshold distance applied to other mobile terminals (terminals on moving vehicles not in space). For terminals on non-GEO satellites, the threshold distance may be greater because they have higher speeds and more predictable trajectories (e.g., generally do not change direction). In some examples, trajectory information calculated for the terminal 440 for near-miss / potential collision detection operations may be used to assist in handover decisions, such as determining which beam the terminal 440 enters and the transition time for the beam handover.

[0051] The terminal 440 may be coupled to a second antenna 420-2. In some examples, the second antenna 420-2 may be configured for a frequency band associated with a network of GEO satellites. The second antenna 420-2 may be configured for the same or a different frequency band as the first antenna 420-1.

[0052] In some examples (e.g., when the non-GEO satellite is a communications satellite), communications manager 445 can interface with a communications manager included in payload 430. In such cases, the communications manager of payload 430 can be configured to multiplex satellite communications with positioning data generated for non-GEO satellite 415, and in some examples, the communications manager of payload 430 can transmit communications data and positioning data using first antenna 420-1 (in such cases, second antenna 420-2 may be omitted). Alternatively, communications manager 445 and the communications manager in payload 430 may operate in combination to transmit communications data and positioning data over multiplexed communications resources (in such cases, the communications managers may share first antenna 420-1 and may omit second antenna 420-2). In other examples, communications manager 445 can transmit positioning data independently from the communications manager in payload 430 (e.g., by using different frequency bands and different antennas).

[0053] In some examples, non-GEO satellite 415 may be a communications satellite that can also support communications within a frequency band used by terminal 440. In such cases, terminal 440 may not include communications manager 445, and transmitter 455 may periodically transmit positioning data over a set of time and frequency resources within a frequency band also used for communications by payload 430. In such examples, the communications manager in payload 430 may accommodate the periodic transmissions from transmitter 455 by refraining from transmitting communications data using the set of time and frequency resources used by transmitter 455.

[0054] In some examples, the transceiver 425, payload 430, communications manager 445, transmitter 455, positioning component 450, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting means for performing the functions described in this disclosure. In some examples, the processor and memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by the processor executing instructions stored in the memory).

[0055] Additionally or alternatively, in some examples, the transceiver 425, payload 430, communications manager 445, transmitter 455, positioning component 450, or various combinations or components thereof, may be implemented in code executed by a processor (e.g., as communications management software or firmware). When implemented in code executed by a processor, the functions of the transceiver 425, payload 430, communications manager 445, transmitter 455, positioning component 450, or various combinations or components thereof, may be performed by a general-purpose processor, a DSP, a central processing unit (CPU), an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as a means for performing or otherwise supporting the functions described in this disclosure).

[0056] FIG. 5 illustrates an example ground station that supports tracking of low earth orbit satellites according to embodiments described herein.

[0057] Ground station 530 may be an example of or may include components of ground station 230, as described with reference to Figure 2. Ground station 530 may include components for two-way communication, including components for transmitting and receiving components and for processing data received in the communication. Ground station 530 may include antenna 505, transceiver 510, communications manager 515, processor 520, near-miss / collision manager 525, memory 550, and network interface 560.

[0058] Antenna 505 may be configured to receive or transmit information from or to a satellite using radio frequency (RF) signals. Antenna 505 may include a parabolic dish. To receive a signal, antenna 505 may reflect the received signal to a focal point where the antenna feed passes the signal to a receive chain. To transmit a signal, antenna 505 may reflect the signal originating from the antenna feed at the focal point.

[0059] The transceiver 510 may communicate bidirectionally with another wireless transceiver. The transceiver 510 may also include a modem for modulating signals and providing the modulated signals to the antenna 505. The modem may also demodulate signals received from the antenna 505. The transceiver 510 and the antenna 505 may be examples of a receiver, a transmitter, or both.

[0060] The processor 520 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 520 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 520. The processor 520 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 550) to cause the ground station 530 to perform various functions (e.g., functions or tasks supporting communications for collision detection / warning). For example, the ground station 530 or a component of the ground station 530 may include the processor 520 and the memory 550 coupled to the processor 520, which are configured to perform various functions described herein.

[0061] The memory 550 may include random access memory (RAM) and read-only memory (ROM). The memory 550 may store computer-readable and computer-executable code. The code may include instructions that, when executed by the processor 520, cause the ground station 530 to perform various functions described herein. The code 555 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, the code 555 may not be directly executable by the processor 520, but may (e.g., when compiled and executed) cause a computer to perform functions described herein. In some cases, the memory 550 may include a basic I / O system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices, among other things.

[0062] The communications manager 515 may support satellite communications. In some examples, the communications manager 515 is used to form beams across a coverage area. The communications manager 515 may also be used to handle mobility events, such as handing over a user terminal between satellite beams or handing over a non-GEO satellite between GEO satellites. The communications manager 515 may also be used to schedule communications resources for various devices, generate data messages according to satellite protocols, and map symbols to communications resources.

[0063] In some examples, communications manager 515 may be configured to perform various operations (e.g., receive, monitor, transmit) using or otherwise cooperating with transceiver 510, antenna 505, or any combination thereof. Although communications manager 515 is shown as a separate component, in some examples, one or more functions described with reference to communications manager 515 may be supported or performed by processor 520, memory 550, code 555, or any combination thereof. For example, code 555 may include instructions executable by processor 520 to cause ground station 530 to perform various aspects of lens communications with multiple antenna arrays as described herein, or processor 520 and memory 550 may be otherwise configured to perform or support such operations.

[0064] Network interface 560 may be configured to send and receive information to other networks (e.g., the Internet, a cellular network, a telephone line network, a private network, a government network, etc.) Network interface 560 may convert messages from one protocol to another (e.g., from a satellite protocol to an Internet protocol).

[0065] Near miss / collision manager 525 may be configured to process positioning data received from non-GEO satellites. In some examples, near miss / collision manager 525 receives positioning data for non-GEO satellites from communications manager 515, which may receive the positioning data in communications received from non-GEO satellites (e.g., terminals installed on the non-GEO satellites). Near miss / collision manager 525 may also be used to predict trajectories of non-GEO satellites, detect near misses and potential collisions between non-GEO satellites based on the predicted trajectories, and alert operators about non-GEO satellites at risk. Near miss / collision manager 525 may include a trajectory predictor 535, a near miss / collision detector 540, and a warning system 545.

[0066] Trajectory predictor 535 may be configured to predict the trajectories (or orbits) of the non-GEO satellites, for example, based on positioning data received from the non-GEO satellites. In some examples, trajectory predictor 535 may continuously update the trajectories of the non-GEO satellites, for example, each time new positioning data is received.

[0067] Near miss / collision detector 540 may be configured to detect near misses between non-GEO satellites, for example, to detect whether any non-GEO satellite is predicted to come within a threshold distance of another non-GEO satellite. Near miss / collision detector 540 may also be configured to detect potential collisions between non-GEO satellites. Near miss / collision detector 540 may detect near misses and potential collisions by comparing the trajectories of the non-GEO satellites to each other and determining whether any of the non-GEO satellites are predicted to come within a threshold distance of each other over a set of future time periods (e.g., every minute of a future five-hour period).

[0068] Warning system 545 may be configured to warn operators of non-GEO satellites associated with a near miss or potential collision event. Warning system 545 may send a notification to the operators of the non-GEO satellites. In some examples, warning system 545 may send a warning to the operators of the non-GEO satellites using network interface 560. In some examples, network interface 560 may be configured to provide warning messages received from warning system 545 to a telephone network (e.g., as a robocall), the Internet, a private network, or a government network (e.g., as an email or notification configured according to an application programming interface for a program used at a satellite control center). In some examples, the private network is a network controlled by the satellite operator, and the government network is a network operated by NORAD.

[0069] In some examples, the communications manager 515, the transceiver 510, the near-miss / collision manager 525, or various combinations or components thereof, may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting means for performing the functions described in this disclosure. In some examples, the processor and memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by the processor executing instructions stored in the memory).

[0070] Additionally or alternatively, in some examples, communications manager 515, transceiver 510, near-miss / collision manager 525, or various combinations or components thereof, may be implemented in code 555 (e.g., as communications management software or firmware) executed by processor 520. When implemented in code 555 executed by processor 520, the functions of communications manager 515, transceiver 510, near-miss / collision manager 525, or various combinations or components thereof, may be performed by a general-purpose processor, a DSP, a central processing unit (CPU), an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as a means for performing or otherwise supporting the functions described in this disclosure).

[0071] FIG. 6 illustrates an example set of operations to support tracking of low earth orbit satellites, according to embodiments described herein.

[0072] Process flow 600 may be performed by a first ground station 601, a GEO satellite 605, and a non-GEO satellite 615, which may be examples of the ground station, GEO satellite, and non-GEO satellite described with reference to Figures 1-5, respectively.

[0073] In some examples, process flow 600 illustrates an exemplary series of operations performed to support tracking of low earth orbit satellites. For example, process flow 600 illustrates the operations of non-GEO satellites (configured for functions other than communications, e.g., imaging, surveillance, global positioning, etc.) to indicate their location to a ground station via a GEO satellite.

[0074] It is understood that one or more of the operations described in process flow 600 may be performed before or after the process, may be omitted, may be replaced by, supplemented with, or combined with other operations. Also, additional operations not included in process flow 600 may be included as described herein.

[0075] In some examples, the non-GEO satellite 615 has a connection with a second ground station 618, which may be an example of the ground station described with reference to FIG. 1 . In some examples, the non-GEO satellite 615 is an example of the fourth non-GEO satellite 215-4 of FIG. 2 , and the second ground station 618 is an example of the third ground station 230-3 of FIG. 2 . The non-GEO satellite 615 may include a payload 616 and a transmitter 617. The payload 616 may be configured to support a function (which may also be referred to as a purpose) of the non-GEO satellite 615. In some examples, the payload 616 is used for monitoring ground or airborne devices, image capture, global positioning operations, or a combination thereof. The transmitter 617 may be configured to transmit positioning data for the non-GEO satellite to the GEO satellite 605. In some examples, the transmitter 617 may be coupled to a positioning component (e.g., the positioning component 450 of FIG. 4 ). In some examples, the transmitter 617 may be included in a terminal (eg, terminal 440 of FIG. 4) that has a subscription to a satellite communications network that includes the first ground station 601 and the GEO satellite 605.

[0076] In block 619, the first ground station 601 (e.g., a network operations center coupled to the first ground station 601) may allocate resources for transmitting positioning data from non-GEO satellites. The first ground station 601 may also allocate resources for transmitting user data from user terminals served by the satellite communications network. In some examples, the first ground station 601 allocates resources for positioning data transmission that are multiplexed (e.g., in time, in frequency, or using codes) with resources for user data transmission. A beam may include multiplexed resources, and in some examples, positioning data and user data resources are multiplexed in different ways on different beams. In other examples, positioning data may use common resources across multiple beams. In some examples, positioning data resources occur periodically. Also, in some examples, a set of positioning data resources is allocated to a group of non-GEO satellites. In some examples, after the handover procedure is complete, the set of positioning data resources assigned to the non-GEO satellite in a first beam may be different (e.g., use different time resources, frequency resources, or different codes) than another set of positioning data resources assigned to the non-GEO satellite in another beam. In some cases, the first ground station 601 broadcasts different positioning data allocations in different beams.

[0077] At arrow 620, the first ground station 601 can broadcast control information in one or more beams used to allocate communication resources (e.g., periodic communication resources) to non-GEO satellites. The transmitter 617 (or a terminal including the transmitter 617) can receive the broadcast control information and, based on the broadcast control information, identify the location of the communication resources for transmitting positioning data.

[0078] At arrow 621, the second ground station 618 can transmit control information to the non-GEO satellite 615. In some examples, the control information includes command information that can be used to change the position, orientation, or both of the non-GEO satellite 615. Additionally or alternatively, the control information may include control information used to control functionality of the payload 616 of the non-GEO satellite 615, for example, to change the image resolution, the area captured by the payload 616, etc.

[0079] In block 625, the payload 616 of the non-GEO satellite 615 may acquire an image of the geographic region, for example, based on command data received from the second ground station 618. Additionally or alternatively, the payload 616 may also determine positioning information for the connected device. In some examples, whether the payload 616 acquires imager information or positioning information is based on the purpose of the payload 616, which may be fixed or configurable.

[0080] At arrow 630, the payload 616 of the non-GEO satellite 615 can transmit the image to a second ground station 618. Additionally or alternatively, the payload 616 can also transmit positioning information to the second ground station 618.

[0081] At arrow 635, the transmitter 617 of the non-GEO satellite 615 can transmit positioning data to the GEO satellite 605. In some examples, the transmitter 617 transmits the positioning data over resources (e.g., frequency bands, time resources, frequency resources, or any combination thereof) allocated or reserved for transmission of positioning data for the non-GEO satellite. In some examples, the resources are periodic (e.g., resources may occur every second), and the transmitter 617 transmits over the resources periodically. In some examples, the transmitter 617 can transmit the positioning data using a frequency band that is the same as or different from a frequency band used for communication between the second ground station 618 and the non-GEO satellite 615. In some examples, the first ground station 601 broadcasts control information indicating the allocated resources, and the transmitter 617 can identify the allocated resources based on receipt of the broadcasted control information.

[0082] In some examples, the transmitter 617 is part of a transceiver included in a terminal having a subscription to a satellite communications network including the first ground station 601 and the GEO satellite 605. In some examples, a network operations center of the satellite communications network schedules resources for the terminal to receive communications from and transmit communications to the satellite communications network. In some examples, the communications received from the satellite communications network are used to indicate a set of resources (e.g., dynamic resources or periodic resources) on which the terminal is scheduled to transmit information to the satellite communications network. Based on receiving the indication of the set of resources, the terminal can use the transmitter 617 to transmit positioning data of the non-GEO satellite 615 to the GEO satellite 605 via the set of resources. In some examples, the transmitter 617 can transmit the positioning data using a frequency band that is the same as or different from the frequency band used for communications between the second ground station 618 and the non-GEO satellite 615.

[0083] GEO satellite 605 can relay positioning data transmitted from non-GEO satellites to first ground station 601. In some examples, GEO satellite 605 relays positioning data in signals that include additional positioning data received from other non-GEO satellites. Additionally or alternatively, GEO satellite 605 can relay positioning data in signals that include user data received from other non-GEO satellites (e.g., non-GEO satellites configured to support satellite communications).

[0084] In block 640, the first ground station 601 may process the positioning data received from the non-GEO satellites and other non-GEO satellites, for example, as described herein with reference to FIG.

[0085] FIG. 7 illustrates an example set of operations to support tracking of low earth orbit satellites, according to embodiments described herein.

[0086] Process flow 700 may be performed by a first ground station 701, a GEO satellite 705, which may be examples of the ground stations and GEO satellites described with reference to Figures 1-6, respectively. Process flow 700 may also be performed by a non-GEO satellite 715, which may be an example of the non-GEO satellite described with reference to Figures 1-6. In some examples, process flow 700 illustrates an exemplary series of operations performed to support tracking of a low-earth orbit satellite. For example, process flow 700 illustrates the operations of a non-GEO satellite configured for communication to indicate its position to a ground station via a GEO satellite.

[0087] It is understood that one or more of the operations described in process flow 700 may be performed before or after the process, may be omitted, may be replaced by, supplemented with, or combined with other operations. Also, additional operations not included in process flow 700 described herein may be included.

[0088] In some examples, the non-GEO satellite 715 is part of a satellite communications network that includes the first ground station 701 and the GEO satellite 705. In such examples, the GEO satellite 705 and the non-GEO satellite 715 may be used to relay communications between the first ground station 701 and a user terminal, such as the user terminal 719. In some examples, the non-GEO satellite 715 has a direct connection to the first ground station 701 or an indirect connection to the first ground station 701 through another ground station, such as the ground station network 718. The non-GEO satellite 715 may be an example of the first non-GEO satellite 215-1 or the Mth non-GEO satellite 215-M of FIG. 2 .

[0089] At block 720, the first ground station 701 may allocate resources for positioning data, user data, or both, as similarly described with reference to block 619 of Figure 6. At arrow 721, the first ground station 701 may broadcast control information including an allocation (e.g., periodic allocation) of communications resources for positioning data transmission, as similarly described with reference to arrow 620 of Figure 6.

[0090] At arrow 722, a first ground station 701 can transmit network data (e.g., network management signaling, user data signaling such as voice or data information, etc.) to a GEO satellite 705. The GEO satellite 705 can relay the user data to a non-GEO satellite 715, whose payload 716 can relay the user data to a user terminal 719.

[0091] At arrow 725 , ground station network 718 can similarly transmit user data to non-GEO satellite 715 , and payload 716 can relay the user data to user terminal 719 .

[0092] At arrow 730 , user terminal 719 can transmit user data to ground station network 718 based on user data received from ground station network 718 via payload 716 of non-GEO satellite 715 , for example.

[0093] At arrow 735, the user terminal 719 can transmit user data to the first ground station 701 via payload 716 of the non-GEO satellite 715 and the GEO satellite 705, for example, based on user data received from the first ground station network 708 via the GEO satellite 705 and the non-GEO satellite 715. In some examples, the user terminal 719 can transmit user data to the first ground station 701 via payload 716 if the user data is intended for a distant region, i.e., a device on the other side of the Earth. In some examples, the user terminal 719 can be configured to transmit data to only one of the first ground station 701 or the ground station network 718. In other examples, the user terminal 719 can be configured to transmit a first set of user data (e.g., user data intended for locations outside the region) to the first ground station 701 and a second set of user data (e.g., user data intended for locations within the region) to the ground station network 718. In some examples, the user terminal 719 transmits the first set of user data and the second set of user data simultaneously.

[0094] In some examples, non-GEO satellite 715 and ground station network 718 are not part of the satellite communications network that includes first ground station 701 and GEO satellite 705, but instead are part of a different satellite communications network operated by a different operator than the satellite communications network. In such cases, GEO satellite 705 can be said to be in a different constellation than non-GEO satellite 715. Also, communications transmitted by arrows 722 and 735 may not occur.

[0095] At arrow 740, a transmitter 717 of a non-GEO satellite 715 may transmit positioning data to a GEO satellite 705, as similarly described with reference to arrow 635 of Figure 6. In some examples, the transmitter 617 periodically transmits the positioning data in assigned or reserved resources (e.g., in an assigned or reserved frequency band, an assigned or reserved time resource, an assigned or reserved frequency resource, or any combination thereof).

[0096] In some examples, the transmitter 717 is part of a transceiver included in a terminal having a subscription to a satellite communications network, as also described with reference to arrow 635 in FIG. 6 . In some examples, if the non-GEO satellite 715 is included in the same satellite communications network as the first ground station 701 and the GEO satellite 705, the positioning data of the non-GEO satellite 715 may be multiplexed with user data transmitted from the payload 716 to the GEO satellite 705. For example, the signal generated by the transmitter 717 may be combined with the signal generated by the payload 716 and transmitted via the same antenna. In other examples, the transmitter 717 may transmit positioning information to the GEO satellite 705 separately from the user data transmitted from the payload 716, e.g., using a different frequency band, reserved communications resources within the same frequency band, etc.

[0097] In block 745, the first ground station 601 may process the positioning data received from the non-GEO satellites and other non-GEO satellites, for example, as described herein with reference to FIG.

[0098] FIG. 8 illustrates an example set of operations to support tracking of low earth orbit satellites, according to embodiments described herein.

[0099] Flowchart 800 may be performed by a ground station, a control station, or a combination thereof, which may be examples of the ground stations or control stations described with reference to Figures 2, 3, and 5-7. In some examples, flowchart 800 illustrates an exemplary series of operations performed to support tracking of low-earth orbit satellites. For example, flowchart 800 illustrates operations for detecting and reporting near misses / potential collisions between low-earth orbit satellites.

[0100] It is understood that one or more of the operations described in flowchart 800 may be performed before or after the process, may be omitted, may be replaced by, supplemented with, or combined with other operations. Also, additional operations not included in flowchart 800 may be included as described herein.

[0101] In block 805, positioning data for a plurality of non-GEO satellites may be received via GEO satellites. In some examples, the positioning data may include global positioning coordinates, velocity, altitude, tilt, or any combination thereof. In some examples, the positioning data may be received periodically (e.g., every second). In some examples, the positioning data may be received using reserved resources (e.g., reserved frequency bands, reserved time resources, reserved frequency resources, or any combination thereof).

[0102] At block 810, a trajectory may be calculated for each of the non-GEO satellites based on the received positioning data. In some examples, the trajectory is calculated based on past positioning data received for the non-GEO satellites (e.g., based on differences between sets of positioning data), current positioning data (e.g., velocity) received from the non-GEO satellites, or both. In some examples, the trajectory may be recalculated for the non-GEO satellites each time positioning data for the non-GEO satellites is received. If positioning data for a non-GEO satellite is not received, the trajectory may remain unchanged or may be updated based on predicted positioning data for the non-GEO satellites.

[0103] In block 815, near misses and potential collisions between the non-GEO satellites may be predicted based on the calculated trajectories. In some examples, the calculated trajectories may be compared to one another (e.g., overlaid on one another) to determine whether any of the non-GEO satellites will momentarily come within a threshold distance of one another. In some examples, a near miss, a potential collision, or both may be detected between a set of one or more non-GEO satellites based on the calculated trajectories, e.g., based on a determination that a first non-GEO satellite will come within 100 meters of a second non-GEO satellite.

[0104] In block 820, an operator associated with the set of one or more non-GEO satellites may be determined. In some examples, all of the non-GEO satellites in the set of non-GEO satellites are determined to be operated by the same operator. In some examples, one of the non-GEO satellites in the set of non-GEO satellites is determined to be operated by a first operator and another of the non-GEO satellites is determined to be operated by a second operator.

[0105] In block 825, an avoidance action may be determined for a set of one or more non-GEO satellites. In some examples, the avoidance action may be for a first non-GEO satellite to change its inclination by a certain amount. In some examples, the avoidance action may be for a first non-GEO satellite to change its inclination by a certain amount in a first direction and a second non-GEO satellite to change its inclination by a certain amount in an opposite direction. In some examples, the avoidance action is determined based on the calculated trajectories of all or a subset of the non-GEO satellites. For example, the proposed avoidance action may be selected such that the avoidance action does not result in a near miss or collision event with another non-GEO satellite.

[0106] In block 830, an alert may be communicated to each operator of the non-GEO satellites that a set of one or more non-GEO satellites has been identified as being at risk of collision. In some examples, alerting each operator may include sending a robocall to both operators, sending an email to both operators, sending an application-specific notification to an application running in the operator's control center, or triggering any combination thereof. Each of the various alerts may include information about the trajectory of the at-risk non-GEO satellite, suggested evasive actions, etc. In some examples, alerts may be sent with various levels of priority, with an impending collision alert being the highest priority alert. In some examples, high-priority alerts are communicated using all available means for communicating alerts, more intrusive means (e.g., application-specific alerts), or to a dedicated endpoint. Low-priority alerts may be communicated using less intrusive means, such as automated email. After receiving the alert, the operator can decide whether to take the suggested evasive action, another action, or no action. When action is taken, the operator can send commands to each non-GEO satellite to change its orbit.

[0107] In some examples, a warning may be communicated to a non-GEO satellite that is at risk of collision. In such cases, the warning may include a suggested evasive action that the non-GEO satellite can decide whether to take. In some examples, if the warning indicates an imminent collision, the non-GEO satellite may automatically take the suggested evasive action. Additionally or alternatively, the warning may be communicated to a government agency that tracks the location of objects in space, such as NORAD.

[0108] FIG. 9 illustrates an example set of operations for tracking low earth orbit satellites according to embodiments described herein.

[0109] Method 900 may be performed by components of a ground station, a control station, or a combination thereof, which may be examples of the ground stations or control stations described with reference to Figures 2, 3, and 5-7. In some examples, the ground station or control station may execute a set of instructions to control functional elements of the ground station or control station to perform the described functions. Additionally or alternatively, the ground station or control station may use dedicated hardware to perform aspects of the described functions.

[0110] At 905, method 900 may include receiving positioning data for a plurality of non-geostationary satellites from a plurality of non-geostationary satellites in respective first orbits via one or more satellites in one or more respective second orbits, where the one or more respective second orbits are higher than the respective first orbits. The operations of 905 may be performed in accordance with embodiments disclosed herein. In some examples, aspects of the operations of 905 may be performed by a transceiver as described herein with reference to FIG. 5.

[0111] At 910, method 900 may include calculating a plurality of trajectories for a plurality of non-geostationary satellites based at least in part on the positioning data. The operations of 910 may be performed in accordance with embodiments disclosed herein. In some examples, aspects of the operations of 910 may be performed by a trajectory predictor, as described herein with reference to FIG. 5.

[0112] At 915, the method 900 may include predicting that a distance between a first non-geostationary satellite of the plurality of non-geostationary satellites and a second non-geostationary satellite of the plurality of non-geostationary satellites will be less than a threshold distance based at least in part on a first trajectory calculated for the first non-geostationary satellite and a second trajectory calculated for the second non-geostationary satellite, where the plurality of trajectories include the first trajectory and the second trajectory. The operations of 915 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 915 may be performed by a near-miss / collision detector, as described herein with reference to FIG. 5.

[0113] At 920, method 900 may include communicating, based at least in part on the prediction, an alert that the distance between the first non-geostationary satellite and the second non-geostationary satellite is predicted to be less than a threshold distance. The operations of 920 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 920 may be performed by an alert system, as described herein with reference to FIG. 5.

[0114] In some examples, an apparatus described herein may perform a method(s), such as method 900. The apparatus may include mechanisms, circuits, logic, means, or instructions (e.g., a non-transitory computer-readable medium storing instructions executable by a processor) for: receiving positioning data for a plurality of non-geostationary satellites from a plurality of non-geostationary satellites in respective first orbits via one or more satellites in one or more respective second orbits, wherein the one or more respective second orbits are higher than the respective first orbits; calculating a plurality of trajectories for the plurality of non-geostationary satellites based at least in part on the positioning data; predicting that a distance between a first non-geostationary satellite of the plurality of non-geostationary satellites and a second non-geostationary satellite of the plurality of non-geostationary satellites will be less than a threshold distance based at least in part on a first trajectory calculated for the first non-geostationary satellite and a second trajectory calculated for the second non-geostationary satellite, the plurality of trajectories including the first trajectory and the second trajectory; and communicating, based at least in part on the prediction, an alert that the distance between the first non-geostationary satellite and the second non-geostationary satellite is predicted to be less than the threshold distance.

[0115] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for receiving second positioning data for the plurality of non-geostationary satellites from one or more satellites, and recalculating multiple trajectories for the plurality of non-geostationary satellites based at least in part on the second positioning data.

[0116] In some examples of the methods 900 and apparatus described herein, receiving the positioning data may include operations, mechanisms, circuits, logic, means, or instructions for receiving a first portion of the positioning data for a first subset of the plurality of non-geostationary satellites from a first satellite of the one or more satellites during a first time period, and receiving a second portion of the positioning data for a second subset of the plurality of non-geostationary satellites from a second satellite of the one or more satellites during a second time period.

[0117] In some examples of the method 900 and apparatus described herein, periodically receiving positioning data from a plurality of non-geostationary satellites, wherein the period between receiving a set of positioning data from each of the plurality of non-geostationary satellites may be less than a threshold period.

[0118] In some examples of the methods 900 and devices described herein, the threshold period may be less than 5 minutes.

[0119] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for establishing respective communication links with a plurality of transmitters that may be coupled to respective non-geostationary satellites of the plurality of non-geostationary satellites, wherein receiving the positioning data may be based at least in part on establishing the respective communication links.

[0120] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for allocating a first set of communication resources of satellite beams of one or more satellites to a plurality of terminals including a plurality of transmitters and allocating a second set of communication resources of the satellite beams to a plurality of user terminals based at least in part on establishing respective communication links with the plurality of terminals, and receiving user data from the plurality of user terminals via the first set of communication resources and receiving positioning data from the plurality of terminals via the second set of communication resources.

[0121] In some examples of the methods 900 and apparatus described herein, the first constellation includes one or more satellites and the second constellation includes at least a subset of a plurality of non-geostationary satellites.

[0122] In some examples of the methods 900 and apparatus described herein, a first satellite network operated by a first operator includes a ground station and one or more satellites, and a second satellite network operated by a second operator includes a subset of a plurality of non-geostationary satellites.

[0123] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for communicating a subscription to use the first satellite network for a terminal of a non-geostationary satellite of the plurality of non-geostationary satellites to a network operations center of the first satellite network, where the terminal includes a transmitter of the plurality of transmitters.

[0124] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for determining that a first non-geostationary satellite may be on a collision course with a second non-geostationary satellite based at least in part on a prediction that a distance between the first non-geostationary satellite and a second non-geostationary satellite may be less than a threshold distance, wherein the warning includes an indication of the predicted collision.

[0125] In some examples of the methods 900 and apparatus described herein, communicating the alert may include operations, mechanisms, circuits, logic, means, or instructions for contacting a first operator of a first non-geostationary satellite and a second operator of a second non-geostationary satellite using a telephone network, a computer network, or both.

[0126] In some examples of the methods 900 and apparatus described herein, contacting the first operator and the second operator using a telephone network may include operations, mechanisms, circuits, logic, means, or instructions for initiating a first automated call to a control center of the first operator and a second automated call to a control center of the second operator.

[0127] In some examples of the methods 900 and apparatus described herein, contacting the first operator and the second operator using a computer network may include operations, mechanisms, circuits, logic, means, or instructions for sending a first email notification to an email account of the first operator and a second email notification to an email account of the second operator, and / or sending the first notification to a program running at a control center of the first operator and the second notification to a program running at a control center of the second operator based at least in part on application programming interfaces of the programs.

[0128] In some examples of the methods 900 and apparatus described herein, the alert may include operations, mechanisms, circuits, logic, means, or instructions for an indication that the distance between the first non-geostationary satellite and the second non-geostationary satellite is less than a threshold distance, an indication of a predicted collision between the first non-geostationary satellite and the second non-geostationary satellite, an indication of evasive action for the first non-geostationary satellite, the second non-geostationary satellite, or both, and any combination thereof.

[0129] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for performing a first handoff of a user terminal on a non-space-based vehicle between satellite beams of one or more satellites based on a first set of parameters associated with the non-space-based vehicle, and performing a second handoff of a terminal on a plurality of non-geostationary satellites between satellite beams of one or more satellites based on a second set of parameters associated with the plurality of non-geostationary satellites.

[0130] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for determining an avoidance action for at least one of the first non-geostationary satellite or the second non-geostationary satellite based at least in part on the plurality of trajectories, wherein the warning includes an instruction for the avoidance action.

[0131] Some examples of the method 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for calculating one or more first potential trajectories for a first non-geostationary satellite based at least in part on one or more first potential corrections by a first non-geostationary satellite, and calculating one or more second potential trajectories for a second non-geostationary satellite based at least in part on one or more second potential corrections by a second non-geostationary satellite, where an avoidance action may be determined based at least in part on the one or more first potential trajectories, the one or more second potential trajectories, or both.

[0132] Some examples of the methods 900 and apparatus described herein may further include operations, mechanisms, circuits, logic, means, or instructions for determining second positioning data for a plurality of non-geostationary satellites using radio detection and ranging techniques, wherein a plurality of trajectories may be further calculated based at least in part on the second positioning data.

[0133] In some examples of the methods 900 and apparatus described herein, the plurality of non-geostationary satellites may be low Earth orbit satellites, the first orbit may be a low Earth orbit, one or more satellites may be geostationary satellites, and one or more respective second orbits may be geostationary orbits.

[0134] It should be noted that these methods describe example implementations, and that the operations and steps may be rearranged or otherwise modified to enable other implementations. In some examples, aspects from two or more methods may be combined. For example, aspects of each method may include steps or aspects of other methods, or other steps or techniques described herein.

[0135] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips referenced throughout the specification may be represented as voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0136] The various example blocks and modules described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a digital signal processor (DSP) and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration).

[0137] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. The mechanisms that implement the functions may also be physically located in different locations, such as being distributed such that portions of the functions are implemented in different physical locations.

[0138] Computer-readable media includes both non-transitory computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, Electrically Erasable Programmable Read-Only Memory (EEPROM), Flash memory, Compact Disc Read-Only Memory (CDROM) or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of medium. As used herein, disk and disc include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0139] As used herein, including the claims, "or" used in a list of items (e.g., a list of items prefaced by a phrase such as "at least one" or "one or more") indicates an inclusive list, such as, for example, the listing "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase "based on" should not be construed as a reference to a limited set of conditions. For example, an exemplary process described as "based on condition A" could be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" is to be interpreted the same as the phrase "based at least in part on."

[0140] In the accompanying drawings, similar components or features may have the same reference label. Additionally, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes between the similar components. When only a first reference label is used within a specification, the description applies to any of the similar components with the same first reference label, regardless of a second reference label or any other subsequent reference labels.

[0141] The description set forth herein with reference to the accompanying drawings describes exemplary configurations and does not represent every embodiment that may be implemented or fall within the scope of the claims. As used herein, the term "exemplary" means "serving as an example, instance, or illustration," and not "preferred" or "advantageous over other embodiments." The detailed description includes specific details for the purpose of providing an understanding of the described technology; however, these technologies may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described embodiments.

[0142] The description herein is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the embodiments and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method (900) for satellite operation at a ground station (230, 530), comprising: receiving, from a plurality of terminals (440) located on a plurality of non-geostationary satellites (115, 215, 415) in respective first orbits, positioning data determined by the plurality of terminals (440) with respect to the plurality of non-geostationary satellites (115, 215, 415) via a first connection relayed through one or more geostationary satellites (105, 205) in one or more respective second orbits (120); the one or more respective second orbits (120) include one or more geostationary orbits; one or more of the plurality of non-geostationary satellites (115, 215, 415) are controlled by a first operator (265, 365) different from a second operator (265, 365) of the one or more geostationary satellites (105, 205) and are configured to communicate signaling related to purposes of one or more of the plurality of non-geostationary satellites (115, 215, 415) directly with a second ground station (230) via a second connection; calculating a plurality of trajectories of the plurality of non-geostationary satellites (115, 215, 415) based at least in part on the positioning data; determining that a first non-geostationary satellite (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415) is heading toward a collision with a second non-geostationary satellite (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415), the determining being based at least in part on a prediction that a distance between a first trajectory calculated for the first non-geostationary satellite (115, 215, 415) and a second trajectory calculated for the second non-geostationary satellite (115, 215, 415) is less than a threshold distance, the plurality of trajectories including the first trajectory and the second trajectory; and communicating to the first operator of the first non-geostationary satellite (115, 215, 415), to a third operator of the second non-geostationary satellite (115, 215, 415), or to both, a warning that the distance between the first non-geostationary satellite (115, 215, 415) and the second non-geostationary satellite (115, 215, 415) is predicted to be less than the threshold distance, wherein the warning includes an indication of a predicted collision.

2. receiving second positioning data relating to the plurality of non-geostationary satellites (115, 215, 415) from the one or more geostationary satellites (105, 205); 2. The method (900) of claim 1, further comprising: recalculating the plurality of trajectories of the plurality of non-geostationary satellites (115, 215, 415) based at least in part on the second positioning data.

3. receiving the positioning data, receiving, during a first time period, a first portion of positioning data for a first subset of the plurality of non-geostationary satellites (115, 215, 415) from a first satellite (105, 205) of the one or more geostationary satellites (105, 205); and receiving, during a second time period, a second portion of positioning data for a second subset of the plurality of non-geostationary satellites from a second satellite of the one or more geostationary satellites.

4. The method (900) of any one of claims 1 to 3, further comprising periodically receiving the positioning data from the plurality of non-geostationary satellites (115, 215, 415), wherein a period between receiving the set of positioning data from each of the plurality of non-geostationary satellites (115, 215, 415) is less than a threshold period.

5. 5. The method (900) of claim 4, wherein the threshold period is less than five minutes.

6. 6. The method (900) of claim 1, further comprising: establishing respective communication links (225) with a plurality of transmitters (255, 455) coupled to respective non-geostationary satellites (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415), and wherein receiving the positioning data is based at least in part on establishing the respective communication links (225).

7. allocating a first set of communication resources of satellite beams of the one or more geostationary satellites (105, 205) to the plurality of terminals (440) for communicating the positioning data determined by the plurality of terminals (440) with respect to the one or more non-geostationary satellites (115, 215, 415), and allocating a second set of communication resources of the satellite beams to a plurality of user terminals (250) for communicating user data; 7. The method (900) of claim 6, further comprising: receiving the positioning data from the plurality of terminals (440) via the one or more geostationary satellites (105, 205) using the first set of communication resources; and receiving the user data from the plurality of user terminals (250) via the one or more geostationary satellites (105, 205) using the second set of communication resources.

8. 7. The method (900) of claim 6, wherein a first constellation includes the one or more geostationary satellites (105, 205) and a second constellation includes at least a subset of the plurality of non-geostationary satellites (115, 215, 415).

9. 7. The method of claim 6, wherein a first satellite network operated by the first operator includes the ground station and one or more geostationary satellites, and a second satellite network operated by the second operator includes the one or more non-geostationary satellites.

10. 10. The method of claim 9, further comprising: communicating a subscription to use the first satellite network for a terminal of a non-geostationary satellite of the plurality of non-geostationary satellites to a network operations center of the first satellite network, the terminal including a transmitter of the plurality of transmitters.

11. communicating the alert; 11. The method (900) of any one of claims 1 to 10, comprising contacting the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415) using a telephone network (352), a computer network (354), or both.

12. using the telephone line network (352) to contact the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415); 12. The method (900) of claim 11, comprising initiating a first automated call to a control center (367) of the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and a second automated call to a control center (367) of the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415).

13. using the computer network (354) to contact the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415); sending a first email notification to an email account of the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and a second email notification to an email account of the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415); and 12. The method (900) of claim 11, comprising sending a first notification to a program running at a control center (367) of the first operator (265, 365) of the first non-geostationary satellite (115, 215, 415) and a second notification to a program running at a control center (367) of the third operator (265, 365) of the second non-geostationary satellite (115, 215, 415) based at least in part on an application programming interface of the program, or both.

14. The warning: an indication that the distance between the first non-geostationary satellite (115, 215, 415) and the second non-geostationary satellite (115, 215, 415) is less than the threshold distance; an indication of a predicted collision between the first non-geostationary satellite (115, 215, 415) and the second non-geostationary satellite (115, 215, 415); indicating an avoidance maneuver for the first non-geostationary satellite (115, 215, 415), the second non-geostationary satellite (115, 215, 415), or both; or The method (900) of any one of claims 1 to 13, including any combination thereof.

15. performing a first handoff of a user terminal (250) on a non-space-based vehicle between satellite beams of the one or more geostationary satellites (105, 205) based on a first set of parameters associated with the non-space-based vehicle; The method (900) of any one of claims 1 to 14, further comprising: performing a second handoff of a terminal (440) on the plurality of non-geostationary satellites (115, 215, 415) between the satellite beams of the one or more geostationary satellites (105, 205) based on a second set of parameters associated with the plurality of non-geostationary satellites (115, 215, 415).

16. 16. The method (900) of any one of claims 1 to 15, further comprising: determining an avoidance action for at least one of the first non-geostationary satellite (115, 215, 415) or the second non-geostationary satellite (115, 215, 415) based at least in part on the plurality of trajectories, and wherein the warning includes an indication of the avoidance action.

17. calculating one or more first potential trajectories of the first non-geostationary satellite (115, 215, 415) based at least in part on one or more first potential corrections by the first non-geostationary satellite (115, 215, 415); 17. The method (900) of claim 16, further comprising: calculating one or more second potential trajectories for the second non-geostationary satellite (115, 215, 415) based at least in part on one or more second potential corrections by the second non-geostationary satellite (115, 215, 415), wherein the avoidance action is determined based at least in part on the one or more first potential trajectories, the one or more second potential trajectories, or both.

18. 18. The method (900) of any one of claims 1 to 17, further comprising: determining second positioning data of the plurality of non-geostationary satellites (115, 215, 415) using radio detection and ranging techniques, and wherein the plurality of trajectories are further calculated based at least in part on the second positioning data.

19. The method (900) of any one of claims 1 to 18, wherein the plurality of non-geostationary satellites (115, 215, 415) are low earth orbit satellites, and the respective first orbits are low earth orbits.

20. An apparatus for satellite operation at a ground station (230, 530), comprising: a processor (520); a memory (550) coupled to the processor (520); stored in the memory (550), receiving, from a plurality of terminals (440) located on a plurality of non-geostationary satellites (115, 215, 415) in respective first orbits, positioning data determined by the plurality of terminals (440) with respect to the plurality of non-geostationary satellites (115, 215, 415) via a first connection relayed through one or more geostationary satellites (105, 205) in one or more respective second orbits (120); the one or more respective second orbits (120) include one or more geostationary orbits; one or more of the plurality of non-geostationary satellites (115, 215, 415) are controlled by a first operator (265, 365) different from a second operator (265, 365) of the one or more geostationary satellites (105, 205) and are configured to communicate signaling related to purposes of one or more of the plurality of non-geostationary satellites (115, 215, 415) directly with a second ground station (230) via a second connection; calculating a plurality of trajectories of the plurality of non-geostationary satellites (115, 215, 415) based at least in part on the positioning data; determining that a first non-geostationary satellite (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415) is heading toward a collision with a second non-geostationary satellite (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415), the determining being based at least in part on a prediction that a distance between a first trajectory calculated for the first non-geostationary satellite (115, 215, 415) and a second trajectory calculated for the second non-geostationary satellite (115, 215, 415) is less than a threshold distance, the plurality of trajectories including the first trajectory and the second trajectory; and communicating a warning to the first operator of the first non-geostationary satellite, to a third operator of the second non-geostationary satellite, or to both, that the distance between the first non-geostationary satellite and the second non-geostationary satellite is predicted to be less than the threshold distance, wherein the warning includes an indication of a predicted collision.

21. The instructions may further include: receiving second positioning data relating to the plurality of non-geostationary satellites (115, 215, 415) from the one or more geostationary satellites (105, 205); and recalculating the plurality of trajectories of the plurality of non-geostationary satellites based at least in part on the second positioning data.

22. The instructions for receiving the positioning data may further comprise: receiving, during a first time period, a first portion of positioning data for a first subset of the plurality of non-geostationary satellites (115, 215, 415) from a first satellite (105, 205) of the one or more geostationary satellites (105, 205); and receiving, during a second time period, a second portion of positioning data for a second subset of the plurality of non-geostationary satellites from a second satellite of the one or more geostationary satellites.

23. The instructions may further include: The apparatus of any one of claims 20 to 22, wherein the apparatus is executable by the processor (520) to periodically receive the positioning data from the plurality of non-geostationary satellites (115, 215, 415), wherein a period between receiving the set of positioning data from each of the plurality of non-geostationary satellites (115, 215, 415) is less than a threshold period.

24. The instructions may further include: The apparatus of any one of claims 20 to 23, wherein the apparatus is executable by the processor (520) to establish respective communication links (225) with a plurality of transmitters (255, 455) coupled to respective non-geostationary satellites (115, 215, 415) of the plurality of non-geostationary satellites (115, 215, 415), and wherein receiving the positioning data is based at least in part on establishing the respective communication links (225).

25. The instructions for communicating the alert may further comprise:

25. The apparatus of claim 20, wherein the apparatus is executable by the processor to contact the first operator of the first non-geostationary satellite and the third operator of the second non-geostationary satellite using a telephone network, a computer network, or both.

26. The instructions may further include: performing a first handoff of a user terminal (250) on a non-space-based vehicle between satellite beams of the one or more geostationary satellites (105, 205) based on a first set of parameters associated with the non-space-based vehicle; and performing a second handoff of a terminal (440) on the plurality of non-geostationary satellites (115, 215, 415) between the satellite beams of the one or more geostationary satellites (105, 205) based on a second set of parameters associated with the plurality of non-geostationary satellites (115, 215, 415).

27. The instructions may further include:

27. The apparatus of claim 20, wherein the apparatus is executable by the processor to determine an avoidance action for at least one of the first non-geostationary satellite or the second non-geostationary satellite based at least in part on the plurality of trajectories, and wherein the warning includes an indication of the avoidance action.

28. The instructions may further include:

28. The apparatus of claim 20, wherein the apparatus is executable by the processor to determine second positioning data of the plurality of non-geostationary satellites using radio detection and ranging techniques, and wherein the plurality of trajectories are further calculated based at least in part on the second positioning data.

29. 20. The method of any one of claims 1 to 19, wherein the one or more of the plurality of non-geostationary satellites (115, 215, 415) do not exchange signaling with the one or more geostationary satellites (105, 205) associated with the purpose of the one or more of the plurality of non-geostationary satellites (115, 215, 415).

30. 29. The apparatus of any one of claims 20 to 28, wherein the one or more of the plurality of non-geostationary satellites (115, 215, 415) do not exchange signaling with the one or more geostationary satellites (105, 205) associated with the purpose of the one or more of the plurality of non-geostationary satellites (115, 215, 415).

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