Calibrating radars and tracking space objects

Abstract

To provide technologies for calibrating radars and tracking space objects.SOLUTION: Technologies disclosed herein enable a technique for calibrating a radar based on using an elemental antenna that can be embedded in a housing hosting a set of antenna elements, or an antenna mounted to a reflector. Some of such technologies enable a radar site containing a first 1D phased array 112 and a second 1D phased array 112, where the first 1D phased array sends a set of signals and receives a set of reflections based on the set of signals, and the second 1D phased array receives the set of reflections.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 914,304, filed October 11, 2019, which is hereby incorporated by reference in its entirety for all purposes.

[0002] The present disclosure relates to radar calibration and tracking of space objects. [Background technology]

[0003] There are various techniques for tracking various space objects (e.g., low-orbit objects, satellites, and debris). For example, some space objects can be tracked via 2D phased array radar. However, these systems have technical disadvantages due to their large size, technical complexity, and high economic cost. Some of these technical disadvantages can be overcome by steerable dish radar. However, these systems also have technical disadvantages due to their low tracking rate, mechanical steering, and limited beam capabilities. Summary of the Invention

[0004] In general, the present disclosure enables various techniques for calibrating radar and tracking space objects. For example, some such techniques enable techniques for calibrating radar based on the use of (a) element antennas that can be embedded in a housing that houses a set of antenna elements, or (b) antennas attached to a reflector. For example, some such techniques enable a radar site including a first 1D phased array and a second 1D phased array, where the first 1D phased array transmits a set of signals and receives a set of reflections based on the set of signals, and the second 1D phased array receives the set of reflections.

[0005] In one embodiment, the system includes a defined area, a first frame disposed within the defined area, a first trough reflector disposed within the defined area, the first trough reflector secured to the first frame, the first trough reflector having a first shape, a first longitudinal trough, and a first scale, a first 1D phased array disposed within the defined area, the first 1D phased array supported by the first frame on the first trough reflector such that the first 1D phased array transmits a set of signals through the first trough reflector and receives a set of reflections based on the set of signals through the first trough reflector, and a second 1D phased array disposed within the defined area. a second trough reflector disposed within the defined area, the second trough reflector fixed to the second frame, the second trough reflector having a second shape, a second longitudinal valley, and a second scale, the second shape being the first shape, the second longitudinal valley being parallel to the first longitudinal valley, and the second scale being smaller than the first scale; and a second 1D phased array disposed within the defined area, the second 1D phased array being supported by the second frame on the second trough reflector, such that the second 1D phased array does not transmit any signals through the second trough reflector and receives a set of reflections based on the set of signals through the second trough reflector. [Brief explanation of the drawings]

[0006] [Figure 1] 1 illustrates an embodiment of a radar site according to the present disclosure. [Figure 2] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 3] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 4] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 5] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 6] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 7] 1 illustrates multiple views of a radar site according to the present disclosure. [Figure 8] 1 illustrates several embodiments of transmitting or receiving assemblies according to the present disclosure. [Figure 9] 1 illustrates an embodiment of multiple transmitting or receiving assemblies supported via a catwalk according to the present disclosure. [Figure 10] 1 illustrates an embodiment of a diagram of a radar site according to the present disclosure. [Figure 11] 1 illustrates an embodiment of a diagram of a dispatching control center and a 1D phased array according to the present disclosure. [Figure 12] 1 illustrates an embodiment of a frame supporting a 1D phased array on a trough reflector according to the present disclosure. [Figure 13] 1 illustrates an embodiment of a process for determining an initial orbit determination in the context of a pair of diagrams illustrating satellite orbits intersecting a first field of view and a second field of view according to the present disclosure. [Figure 14] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 15] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 16] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 17] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 18] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 19] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 20] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 21] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 22] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 23] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 24] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 25] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 26] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 27] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 28] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 29] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 30] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 31] 1 illustrates an embodiment of a process and software architecture for determining an initial orbit determination according to the present disclosure. [Figure 32] 1 illustrates an embodiment of an interferometric technique according to the present disclosure. [Figure 33] 1 illustrates an embodiment of an interferometric technique according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] In general, the present disclosure enables various techniques for calibrating radar and tracking space objects. For example, some such techniques enable radar calibration techniques based on the use of (a) element antennas that can be embedded in a housing containing a set of antenna elements, or (b) antennas attached to a reflector. For example, some such techniques enable a radar site including a first 1D phased array and a second 1D phased array, where the first 1D phased array transmits a set of signals and receives a set of reflections based on the set of signals, and the second 1D phased array receives the set of reflections. The present disclosure will now be more fully described with reference to FIGS. 1-33, in which various embodiments of the present disclosure are shown. The present disclosure may be embodied in many different forms and should not be construed as necessarily limited to the embodiments disclosed herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the various concepts of the present disclosure to those skilled in the art.

[0008] Various terms used herein may refer to direct or indirect, complete or partial, temporary or permanent, action or omission. For example, when an element is referred to as being "on," "connected to," or "coupled to" another element, the element may be directly on the other element, connected to or coupled to the other element, or intervening elements may be present, including indirect or direct variations. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, there are no intervening elements present.

[0009] The various terms used herein are for the purpose of describing embodiments and are not necessarily intended to limit the disclosure. As used herein, the various singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. The various terms "comprises," "includes," and / or "comprising," "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

[0010] As used herein, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless otherwise specified or clear from the context, "X utilizes A or B" is intended to mean any of the set of natural inclusive permutations. That is, if X utilizes A, X utilizes B, or X utilizes both A and B, then "X utilizes A or B" is satisfied under any of the above cases.

[0011] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. Various terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the meaning in the context of the relevant art, and should not be interpreted in an idealized and / or overly formal sense unless explicitly defined in this specification.

[0012] Furthermore, relative terms such as "lower," "belower," "upper," and "upper" may be used herein to describe the relationship of one element to another element as shown in the accompanying set of illustrative drawings. Such relative terms are intended to encompass different orientations of the illustrated technology in addition to the orientation depicted in the accompanying set of drawings. For example, if a device in the accompanying set of drawings is turned over, elements described as being "below" other elements would be oriented "upper" other elements. Similarly, if a device in one of the illustrative drawings is turned over, various elements described as being "below" or "below" other elements would be oriented "upper" other elements. Thus, various illustrative terms such as "lower" and "lower" can encompass both an orientation of upper and lower.

[0013] As used herein, the terms "about" or "substantially" refer to a + / - 10% variation from the nominal value / term. Such a variation is always included in any given value / term provided herein, whether or not such a variation is specifically referred to.

[0014] Terms such as "first," "second," and the like may be used herein to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not necessarily be limited by such terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the various teachings of the present disclosure.

[0015] Features described with respect to particular embodiments may be combined and subcombined in and / or with various other embodiments. Also, different aspects and / or elements of the embodiments as disclosed herein may be combined and subcombined in a similar manner. Furthermore, some embodiments, whether individually and / or collectively, may be components of larger systems, and other procedures may take precedence and / or their application may be modified in other ways. Furthermore, some steps may be required before, after, and / or concurrently with the embodiments as disclosed herein. It should be noted that, at least as disclosed herein, any and / or all methods and / or processes may be performed, at least in part, by at least one entity in any manner.

[0016] Embodiments of the present disclosure are described herein with reference to illustrations of idealized embodiments (and intermediate structures) of the present disclosure. As such, variations from the illustrated shapes as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, the various embodiments of the present disclosure should not be construed as necessarily limited to the various shapes of regions shown herein but should include, for example, deviations in shapes that result from manufacturing.

[0017] As disclosed herein, any and / or all elements can be formed from the same structurally continuous piece, e.g., unitary, and / or can be separately manufactured and / or connected, e.g., assembly and / or module. As disclosed herein, any and / or all elements can be manufactured via any manufacturing process, whether additive manufacturing, subtractive manufacturing, and / or any other type of manufacturing. For example, some manufacturing processes include three-dimensional (3D) printing, laser cutting, computer numerical control routing, milling, pressing, stamping, vacuum forming, hydroforming, injection molding, lithography, etc.

[0018] FIG. 1 illustrates an embodiment of a radar site according to the present disclosure. FIGS. 2-7 illustrate multiple views of a radar site according to the present disclosure. FIG. 8 illustrates multiple embodiments of multiple transmit or receive assemblies according to the present disclosure. FIG. 9 illustrates an embodiment of multiple transmit or receive assemblies supported via a catwalk according to the present disclosure. FIG. 10 illustrates an embodiment of a radar site view according to the present disclosure. FIG. 11 illustrates an embodiment of a dispatching control center and a view of a 1D phased array according to the present disclosure. FIG. 12 illustrates an embodiment of a frame supporting a 1D phased array on a trough reflector according to the present disclosure. FIG. 13 illustrates an embodiment of a process for determining an initial orbit determination in light of a pair of views showing the orbit of a satellite intersecting a first field of view and a second field of view according to the present disclosure. FIGS. 14-31 illustrate an embodiment of a process for determining an initial orbit determination, a software architecture therefor, and a comparison of results for determining the orbit of a space object using a TLE technique and results for determining the orbit of a space object using an initial orbit determination technique according to the present disclosure. FIGS. 32-33 illustrate an embodiment of an interferometric technique according to the present disclosure.

[0019] A defined area 100 (e.g., a radar site, enclosed area, fenced area) has a volume of earth 102 and a pad 104 (e.g., concrete, rubber), where the volume of earth 102 supports the pad 104. As shown in FIG. 2, the defined area 100 has a fence line 114 surrounded by a property line 116. The volume of earth 102 rests on the ground, although this can be omitted. The pad 104 houses a first radar pair 120a and a second radar pair 120b.

[0020] As shown in Figure 5, the pad 104 has a first island supporting a first radar, a second island supporting a second radar, and a bridge spanning the first and second islands. As shown in Figure 7, the pad 104 is arranged so that the first and second islands are offset relative to one another (for tracking purposes). However, it should be noted that these configurations can be varied. For example, the bridge can be omitted, the first and second islands can be unoffset, or the pad 104 can be omitted.

[0021] The first radar pair 120a includes a first radar having a first frame 106, a first trough reflector 108 (also referred to as a parabolic cylinder antenna, a parabolic cylindrical antenna, or a parabolic trough antenna), a first catwalk 110, and a first 1D phased array 110. The first frame 106 (e.g., U-shaped or C-shaped with a set of support legs) is positioned within the defined area 100. The first trough reflector 108 is positioned within the defined area 100, fixed (e.g., fastened) to the first frame 106, and has a first shape (e.g., U-shaped, C-shaped), a first vertical trough (e.g., extending in the Z dimension in FIGS. 1, 4, and 5), and a first scale (e.g., size). For example, the first trough reflector 108 can be formed by a group of panels (e.g., metal, alloy, steel, mesh, grid) placed directly adjacent to one another to form a top surface configured to reflect various signals (e.g., radio, optical, etc.). For example, if at least some of the panels are mesh panels with holes therein (e.g., contributing to low cost), the holes can be sized to be smaller than the operating wavelength of the first 1D phased array 110. For example, a small-aperture mesh provides high reflectivity and low leakage. Signal leakage through the mesh increases the antenna backlobe and system temperature. Antenna backlobe refers to energy radiated from the antenna in a direction opposite to the primary radiation direction. An increased backlobe reduces antenna energy radiated in the primary direction. Large-aperture mesh is low-cost, lightweight, and has reduced wind loads. These factors are taken into consideration when designing the mesh openings. Additionally, painting the mesh can protect the material from weathering. White paint reflects sunlight from the trough surface, thereby minimizing thermal deformation of the structure. The materials and methods used to construct the trough reflector can help lower the cost of the first radar. Note that, as shown in Figure 12, the first trough reflector 108 can include a group of calibration antennas 146. How these antennas 146 are used is described further below.

[0022] As shown in FIG. 9 , the first 1D phased array 112 is formed (or arranged) in a first line. The first 1D phased array 112 is disposed within the defined region 100 in the first line. The first 1D phased array 112 is supported (e.g., elevated) by the first frame 106 above the first trough reflector 108, so that the first 1D phased array 112 transmits a set of signals (e.g., radio) through the first trough reflector 108 and receives a set of reflections based on the set of signals through the first trough reflector 108. For example, as shown in FIG. 6 , there can be a reflection pattern 200 in which the first 1D phased array 112 can transmit a set of signals toward the trough reflector 108, which then reflects the set of signals in various directions (e.g., from vertical). For example, the set of signals and the set of reflections can be transmitted and received in a V-shape (e.g., 11 o'clock, 2 o'clock). When the set of signals is reflected by a space object (e.g., a low-orbit object, a satellite, debris), the set of reflections is received through the first trough reflector 108 and then reflected towards the first 1D phased array 112.

[0023] The first radar pair 120a includes a second radar having a second frame 106, a second trough reflector 108 (also referred to as a parabolic cylinder antenna, a parabolic cylindrical antenna, or a parabolic trough antenna), a second catwalk 110, and a second 1D phased array 110. The second frame 106 is disposed within the defined area 100. The second trough reflector 108 is disposed within the defined area 100 and is fixed (e.g., fastened) to the second frame 106 and has a second shape (e.g., U-shaped, C-shaped), a second longitudinal trough (e.g., extending in the Z dimension in FIGS. 1, 4, and 5), and a second scale (e.g., size). For example, the second trough reflector 108 can be formed by a group of panels (e.g., metal, alloy, steel, mesh, grid) placed directly adjacent to one another to form a top surface configured to reflect various signals (e.g., radio, optical). For example, if at least some of the panels are mesh panels with holes therein (e.g., contributing to low cost), the holes can be sized to be smaller than the operating wavelength of the second 1D phased array 110. For example, a small-aperture mesh provides high reflectivity and low leakage. Signal leakage through the mesh increases the antenna backlobe and system temperature. Antenna backlobe refers to energy radiated from the antenna in a direction opposite to the primary radiation direction. An increased backlobe reduces antenna energy radiated in the primary direction. Large-aperture mesh is low-cost, lightweight, and has reduced wind loads. These factors are taken into consideration when designing the mesh openings. Additionally, painting the mesh can protect the material from weathering. White paint reflects sunlight from the trough surface, thereby minimizing thermal deformation of the structure. The materials and methods used in the construction of the trough reflector can help lower the cost of the first radar. Note that, as shown in Figure 12, the second trough reflector 108 can include a group of calibration antennas 146. How these antennas 146 are used is described further below.

[0024] The second shape of the second trough reflector 108 is identical to the first shape of the first trough reflector 108. The second longitudinal valley of the second trough reflector 108 is parallel to the first longitudinal valley of the first trough reflector 108. However, the second scale of the second trough reflector 108 is smaller than (but may be equal to or larger than) the first scale of the first trough reflector 108. For example, the first trough reflector 108 and the second trough reflector 108 have the same shape and orientation (and spacing from one another), but the second trough reflector 108 is a smaller version of the first trough reflector 106. Such a configuration is technically advantageous for various reasons. For example, such a configuration may enable efficient (a) determination of the initial trajectory of a space object, (b) determination of range data to the space object, (c) determination of Doppler data for the space object, (d) angle data for the space object, (e) performance of radar interferometry for the space object, etc. For example, an array of 1D parabolic arrays 108 may be configured to operate together to perform measurements on a satellite by one or more transmit-receive arrays 108 and one or more receive-receive arrays 108 measuring polarization or performing interferometry to obtain a 3D location of the target.

[0025] 9, the second 1D phased array 110 forms (or is arranged in) a second line parallel to the first line. The second 1D phased array 110 is disposed in the defined region 100 in the second line. The second 1D phased array 112 is supported (e.g., elevated) by the second frame 106 on the second trough reflector 108, so that the second 1D phased array 110 does not transmit any signals through the second trough reflector 108. However, the second 1D phased array 110 receives a set of reflections based on the set of signals through the second trough reflector 108. For example, as shown in FIG. 6 , when a set of signals from a first 1D phased array reflects off a space object (e.g., a low-orbit object, satellite, debris), a reflection pattern 200 may exist. The set of reflections is then received through a second trough reflector 108 and then reflected back toward a second 1D phased array 112. For example, the set of reflections may be received in a V-shape (e.g., at 11 o'clock, 2 o'clock). Such a configuration is technically advantageous for a variety of reasons. For example, such a configuration may enable efficient (a) determination of the initial orbit of the space object, (b) determination of range data to the space object, (c) determination of Doppler data relative to the space object, (d) angle data relative to the space object, and (e) performance of radar interferometry relative to the space object. For example, an array of 1D parabolic arrays 108 may be configured to operate together to perform measurements on a satellite by measuring polarization or performing interferometry to obtain the 3D location of the target.

[0026] Note that for each first radar (a many-to-one correspondence), there may be two or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, tens, hundreds, or thousands) of second radars. These second radars may be located inside or outside the defined area 100, regardless of whether the first longitudinal valley of the first trough reflector 108 is parallel to at least two of the longitudinal valleys of the second trough reflector 108 of the second radar. How far these second radars (e.g., trough reflectors) are from the first radar or from each other depends on the signal frequency (e.g., approximately 15 meters from the focal point). For example, the second radars may be randomly distributed within the defined area 100, but accuracy may improve as the distance between the first radar and at least two of the second radars or between at least two of the second radars increases.

[0027] Each of the first and second radars includes a respective catwalk 110 having a first leg 110L, a second leg 110L, and a platform 110P. The first leg 110L is fixed (e.g., assembled, fastened, monolithic) to each frame 106 within the defined area 100. The first leg 110L extends over a respective trough reflector 108. The second leg 110L is fixed (e.g., assembled, fastened, monolithic) to each frame 106 within the defined area 100. The second leg 110L extends over a respective trough reflector 108. The platform 110P is fixed (e.g., assembled, fastened, monolithic) to the first leg 110L and the second leg 1110L within the defined area 100. The platforms 110P extend along (or over) the respective longitudinal valleys of the trough reflectors 108 and house (e.g., support) the respective 1D phased arrays 112. The first radar platform 110P can extend parallel to the second radar platform 110P. Note that there are respective ladders spanning between the pad 104 and the platforms 110P for physical access to each catwalk 110.

[0028] As shown in Figures 1, 3, 4, 5, and 9, the catwalk 110 can be an upright A-shape so that the platform 110P extends over each trough reflector 108. However, as shown in Figure 12, the catwalk 110 can be a tilted V-shape or a tilted A-shape. Regardless of how the catwalk 110 is shaped, the catwalk 110 supporting the first 1D phased array 112 can be structurally identical to the catwalk 110 supporting the second 1D phased array 112, but at a larger scale (scaling up from the second to the first). Similarly, the first radar has a proportionally larger focus than the second radar. For example, as shown in Figure 3, the focus of the first radar is 4 meters, while the focus of the second radar is 2 meters (50% scale down). Similarly, as shown in Figure 3, the first trough reflector 108 and the second trough reflector 108 are centrally aligned.

[0029] As shown in FIG. 8 , the first 1D phased array 112 or the second 1D phased array 112 can include a set of housings 300. In such a configuration, the housings 300 can be positioned on the respective platforms 110P directly adjacent (e.g., side-by-side) to one another on the respective trough reflectors 108 (as shown in FIGS. 1 , 5 , and 9 ). Each housing 300 can include a set of antenna elements 302 (e.g., patch antennas) arranged in a row on the respective housing 300 and facing the respective trough reflectors 108. For example, each housing 300 or each antenna element 302 can be electronically steered to simultaneously beam in different directions, whether independent of or dependent on one another.

[0030] As shown in FIGS. 2, 10, and 11, the defined area 100 includes a container 118 having an interior area sized for a user (e.g., a technician) to walk into, navigate, and exit. For example, the container can include a shipping container, an intermodal container, a building, a tent, a cabin, a booth, a truck, a van, a bus, or other fixed or mobile structure (e.g., on land, in the air, or at sea). For example, the container 118 can be towable, placeable on a truck bed, liftable by a crane, or assembled on-site. The container 118 can be weather-resistant (e.g., in rain, snow, wind, or desert environments) and can have various climate control mechanisms (e.g., air conditioning, vents, humidifiers, dehumidifiers). The container 118 can receive power from a power line, a renewable energy source, a generator, or be battery-powered, any of which can be local or remote to the container 118, whether inside or outside the defined area 100. The container 118 may include plastic, metal, cloth, rubber, wood, alloy, or other suitable material that avoids signal interference with the radar pairs 120a and 120b. The container 118 rests on the pad 104 but may be spaced apart from the pad 104. The container 118 is spaced apart (e.g., avoids physical contact) from the first frame 106, the first trough reflector 108, the first 1D phased array 112, the second frame 106, the second trough reflector 108, and the second 1D phased array 112.

[0031] As shown in FIGS. 10-11 , to operate the first and second radars, the container 118 acts as a dispatching control center and includes logic (e.g., circuitry, a processor, memory, a transmitter, a receiver, a signal splitter) disposed within an interior area. The logic communicates with, and thus controls, the first and second 1D phased arrays. The logic includes a processor 134 (e.g., a server, a GPU, an accelerator card) disposed within the container 118, a transmitter 138 disposed within the container 118, a set of radio frequency (RF) receivers 136 disposed within the container 118, and a network interface 140 (e.g., an RF fiber interface) disposed within the container 118. The transmitter 138 and the set of RF receivers 138 are disposed within the container 118 to be communicatively connected (e.g., interposed) between the processor 134 and the network interface 140.

[0032] 11 , the first 1D phased array 112 transmits a set of signals to the first trough reflector 108, and the processor 134 controls how these signals are generated and transmitted. Thus, external to (or internal to) the container 118 is a signal splitter 142 that receives data from the network interface 140 as originally transmitted by the processor 134 and splits this data for distribution among the housings 300 for transmission by the antenna 302. Thus, the signal splitter 142 is coupled (e.g., electrically, communicatively) to the logic (e.g., the processor 134, the transmitter 138, the network interface 140) and the first 1D phased array 112 (e.g., the housing 300), such that a set of signals is generated based on the signal splitter receiving a set of data from the logic and splitting the set of data for distribution to the housings 300 of the first 1D phased array. However, because each of the first 1D phased array 112 and the second 1D phased array 112 receives reflections from space objects based on a set of signals, there is a group of signal combiners 144 outside (or inside) the container 118. The group of signal combiners 144 combines the sets of reflections from space objects and transmits them to the processor 134 via the network interface 140 and the RF receivers 136. Note that the processor 134 transmits data to the transmitter 138 and receives data from each of the RF receivers 136. Note that the transmitter 138 similarly transmits data to the network interface 140. Note that each of the RF receivers 136 similarly receives data from the network interface 140. Further, note that the network interface 140 transmits data to the signal splitter 142 and receives data from the combiner 144. Further, note that the splitter 142 transmits data to the housing 300 and the combiner 144 receives data from the housing 300.

[0033] The first 1D phased array 112 transmits a set of signals through the first trough reflector 108 based on a first circular polarization and receives a set of reflections through the first trough reflector 108 based on a second circular polarization. The first circular polarization is not the same as the second circular polarization (e.g., quadrant offset). The first circular polarization can be opposite to the second circular polarization. However, the second 1D phased array 112 receives a set of reflections through the second trough reflector 108 based on the first circular polarization and the second circular polarization.

[0034] As shown in FIG. 8 , each of the housings 300 is weatherproof (e.g., in rain, snow, wind, or desert environments) and avoids signal interference between the first radar and the second radar, as disclosed herein. Furthermore, each of the housings 300 has a group of cables / cords 310 extending outward therefrom (e.g., from the top or side). The cables / cords 310 are communicatively coupled to the logic of the container 118 (e.g., the processor 134) and provide power to enable various transmit / receive signal operations, as disclosed herein. Furthermore, each of the housings 300 has a first plate 304 and a second plate 306 arranged relative to one another to form an L-shape or a T-shape. The first plate 304 houses a linearly arranged antenna 302 (e.g., a patch antenna) thereon. As disclosed herein, the first plate 304 faces the respective trough reflector 108 during transmit / transmit. A second plate 306 extends into each housing 300 and houses various circuits that drive / power the antennas 302. Thus, when the antennas 302 are transmitting toward their respective trough reflectors 108, the plate 306 is not visible from the outside due to its extension into the respective housing 300. Each housing 300 also includes an antenna 308 extending outward therefrom (an elementary antenna). The antenna 308 is not disposed on the plate 304 but is spaced therefrom (e.g., within about 2 inches). The antenna 308 is configured to calibrate each of the first radar or second radar as disclosed herein.

[0035] As shown in FIGS. 1, 2, 5, 7, 10, and 13, the defined area 100 includes a first pair 120a and a second pair 120b of radars. The second pair 120b is similar or identical to the radar pair 120a (e.g., in shape, material, or operation). For example, the second pair 120b includes a third radar and a fourth radar. The third radar includes a third frame 106, a third trough reflector 108 (also referred to as a parabolic cylindrical antenna, a parabolic cylindrical antenna, or a parabolic trough antenna), and a third 1D phased array 112. The third frame 106 is disposed within the defined area 100. The third trough reflector 108 is disposed within the defined area 100, is fixed to the third frame 106, and has a third shape, a third longitudinal valley, and a third scale. Similar to the first radar pair 120a, a third 1D phased array 112 is disposed within the defined region 100 and supported by a third frame 106 on a third trough reflector 108, such that the third 1D phased array 112 transmits a set of signals through the third trough reflector 108 and receives a set of reflections from space objects based on the set of signals through the third trough reflector 108. Similarly, the fourth radar includes a fourth frame 106, a fourth trough reflector 108 (also referred to as a parabolic cylindrical antenna, a parabolic cylindrical antenna, or a parabolic trough antenna), and a fourth 1D phased array 112. The fourth frame 106 is disposed within the defined region 100. The fourth trough reflector 108 is disposed within the defined region 100 and is fixed to the fourth frame 106 and has a fourth shape, a fourth longitudinal trough, and a fourth scale. Similar to the first radar pair 120a, the fourth shape is the third shape, the fourth longitudinal valley extends parallel to the third longitudinal valley, and the fourth scale is smaller than the third scale. A fourth 1D phased array 112 is disposed within the defined region 100. Similar to the first radar pair 120a, the fourth 1D phased array 112 is supported by the fourth frame 106 on the fourth trough reflector 108, so that the fourth 1D phased array 112 does not transmit signals through the fourth trough reflector 108 but receives a set of reflections from space objects based on the set of signals through the fourth trough reflector 108.

[0036] Note, however, that as shown in Figures 1, 2, 5, 10, and 13, the first radar pair 120a and the second radar pair 120b are directed toward different (e.g., opposite) sides of the sky (e.g., different fields of view). This configuration can be achieved in various ways. For example, this configuration can be achieved when the second trough reflector 108 of the first radar pair 120a is positioned between the first trough reflector 108 of the first radar pair 120a and the fourth trough reflector 108 of the second radar pair 120b. Similarly, this configuration can be achieved when the fourth trough reflector 108 of the second radar pair 120b is positioned between the second trough reflector 108 of the first radar pair 120a and the third trough reflector 108 of the second radar pair 120b. Similarly, this configuration can be achieved when the second radar of the first radar pair 120a and the fourth radar of the second radar pair 120b are positioned between the first radar of the first radar pair 120a and the third radar of the second radar pair 120b. Furthermore, this configuration can be achieved when the Rx / Rx radar is positioned between the Tx / Rx radar. As a result, a set of reflections from space objects received by the first 1D phased array and the second 1D phased array form a first field of view, and a set of reflections received by the third 1D phased array and the fourth 1D phased array form a second field of view, where the first field of view does not overlap with the second field of view (coverage of different sky regions). This configuration is technically advantageous for various reasons. For example, if the processor 134 is in communication with the first 1D phased array 112, the second 1D phased array 112, the third 1D phased array 112, and the fourth 1D phased array 112, the processor 134 can be programmed to track an orbiting space object within a first field of view (first radar pair 120a) and a second field of view (second radar pair 120b), such that the orbiting space object can be detected at least twice in a single pass over the defined region 100 from within the defined region 100. For example, there can be a 1D phased array Operations Control Center (OCC) interface. In particular, the radar site 100 includes a pair of 1D phased array 112 radars illuminating a parabolic trough reflector 108.The trough reflector 108 is composed of eight octopods 300, each of which can have eight transmit-receive antenna elements. The TxRx troughs 108 (large) transmit and receive, while the RxRx troughs 108 (small) receive only. The TxRx troughs 108 transmit and receive in a single (but opposite) polarization, while the RxRx troughs 108 receive in both polarizations. The troughs 108 are managed by the OCC 118, which generates the transmit signal on the server using a digital transceiver. The transmit signal is sent over fiber (e.g., RF over fiber) to a 64-way (or fewer or more) splitter that feeds all octopods 300. On receive, the octopods 30 are grouped into batches of eight (or fewer or more) and combined using passive optical techniques. The received signal is converted to RF in the OCC and sent to the server array 134 for processing. Similarly, for the RxRx trough 108, the receiver signal is routed to the OCC 118.

[0037] For the first radar pair 120a and the second radar pair 120b, the second longitudinal valley can extend parallel to the fourth longitudinal valley, or the first longitudinal valley can extend parallel to the third longitudinal valley. Note, however, that this configuration may be different if the second longitudinal valley does not extend parallel to the fourth longitudinal valley, or if the first longitudinal valley does not extend parallel to the third longitudinal valley.

[0038] As shown in FIGS. 11-31, another technical advantage of the defined region 100 having the first radar pair 120a and the second radar pair 120b arises in determining the initial trajectory of a space object. In particular, the processor 130 can be in communication with the first 1D phased array 112, the second 1D phased array 112, the third 1D phased array 112, and the fourth 1D phased array 112. Thus, as shown in FIGS. 15-20, the processor 134 can be programmed to cause the first 1D phased array 112 and the second 1D phased array 112 to detect a space object within a first field of view based on a set of reflections from the space object as received by the first trough reflector 108 and the second trough reflector 108. As shown in FIG. 13, this is done based on the trajectory of the space object (e.g., a satellite) that intersects with the first field of view (1D) of the first radar pair 120a. 15-20, the processor 134 can then determine an initial trajectory (e.g., orbital data) for the space object based on this set of reflections. For example, this can be done based on obtaining a first tracklet from the first trough reflector 108 and a second tracklet from the second trough reflector 108, selecting a best candidate (e.g., a dynamic measurement fitter) from each of the first and second tracklets, and then inferring the initial trajectory based on the best tracklet.

[0039] An initial orbit can be determined for various reasons. For example, an initial orbit can be determined when the space object is not listed in a record of a set of records (e.g., new space object) in a database (e.g., relational, in-memory, No-SQL, graphical, cloud) off-chip from the processor (e.g., Amazon cloud computing instance), where the set of records corresponds to a set of space objects other than the space object. For example, an initial orbit can be determined when a space object stored in a record in a database (e.g., relational, in-memory, No-SQL, graphical, cloud) off-chip from the processor (e.g., Amazon cloud computing instance) lacks orbital parameters corresponding to the space object for a predetermined period of time (e.g., data for the space object is stale, or a known space object's orbit needs to be reinitialized, or there have been no or minimal measurements for a predetermined period of time).

[0040] Regardless of why the initial orbit is determined, the processor 134 can create a schedule for the third 1D phased array 112 and the fourth 1D phased array 112 to detect the space object after the initial orbit of the space object is determined. For example, the schedule can include an expected date, time, and location of the space object for the second radar pair 120b. The processor 134 can then cause the third 1D phased array 112 and the fourth 1D phased array 112 to detect the space object within the second field of view based on a set of reflections from the space object as received by the third trough reflector 108 and the fourth trough reflector 108 according to the schedule. This is done based on the orbit of the space object (e.g., a satellite) that intersects with the second field of view (1D) of the second radar pair 120b. The processor 134 can then take an action associated with the initial orbit in response to the space object being detected within the second field of view based on the second set of reflections according to the schedule. Some of such actions may include modifying the initial trajectory so that a new trajectory (e.g., trajectory data) is formed, maintaining the initial trajectory as is, creating a new trajectory (e.g., trajectory data) based on the initial trajectory, etc. Note that because an orbiting space object may be detected at least twice in a single pass over the defined region 100 from within the defined region 100, the processor 134 should be located within the defined region 100 to minimize latency and facilitate real-time processing, as there may be a short period of time (e.g., seconds, tens of seconds) between when the space object is detected by the first radar pair 120a and when the space object is scheduled to be detected by the second radar pair 120b.

[0041] For example, an initial orbit determination based on multiple troughs 108 can be made. In particular, a user (e.g., an engineer, a satellite operator, an insurance company) may desire to be able to detect and form an initial orbit determination for various space objects (e.g., satellites) that are not cataloged (e.g., not included in a database of cataloged space objects) with a single radar site 110, allowing the user to maintain a knowledge store for those space objects and add their data to a catalog (e.g., a database). Thus, a target (e.g., a satellite) may be detected at a first trough 108 or pair of first troughs 108 as disclosed herein, with at least some measurements including a series of range, Doppler, and angle measurements. These measurements are then used to form an initial orbit (which should be performed relatively quickly or in real time). A prediction is then made as to when and where the target will cross a second trough 108 or second pair of troughs 108. The second trough 108 or second pair of troughs 108 is then scheduled to detect the target. This should occur relatively quickly or in real time, as the passage of the second trough 108 or second pair of troughs 108 may be tens of seconds after detection at the first trough 108 or first pair of troughs 108. Detections are then made at the second trough 108 or second pair of troughs 108 based on a schedule. The data is then combined to form an initial orbit determination, which can then be used for follow-up at other radar sites, whether similar or dissimilar to radar site 100.

[0042] As shown in Figures 22-31, with regard to the software architecture that enables the determination of the initial trajectory, there may be a group of scripts (e.g., Python, JavaScript), where one of these scripts performs various environment functions (e.g., file paths, basic settings, input / output library declarations, function calls), and another of these scripts performs various operations in the backend (e.g., time format conversion, trajectory formula conversion, cost function minimization, residual calculation).

[0043] As shown in FIG. 23, a group of scripts is contained within a module that receives data from a configuration file and data from tracklets for each of the first and second radar pairs 120a and 120b. The data from the tracklets is provided by preprocessors provided by each of the first and second radar pairs 120a and 120b. Within the module, the scripts communicate with each other bidirectionally. For example, some measurements and fitted measurement pairs can be sent from one of the scripts (environment functions). Similarly, some fitted parameters, data from the Lambert solver, and fitted initial trajectory data can be sent from one of the scripts (backend). How these operations are performed is shown in FIGS. 24-31.

[0044] 32-33, another technical advantage of having radar pair 120a or radar pair 120b arises when performing radar interferometry. In particular, processor 134 can communicate with first 1D phased array 112 (or third 1D phased array 112) and second 1D phased array 112 (or fourth 1D phased array 112). The processor can then be programmed to perform radar interferometry for a detected space object based on the first 1D phased array 112 transmitting a set of signals toward the space object via the first trough reflector 108 (or the third trough reflector 108) and receiving a set of reflections from the space object by the first 1D phased array 112 (or the third 1D phased array 112) via the first trough reflector 108 (or the third trough reflector 108) and the second 1D phased array 112 (or the fourth 1D phased array 112) via the second trough reflector 108 (or the fourth trough reflector 108). Radar interferometry can include converting a set of time series formed from the set of independent data channels into optimal range, radial velocity, radial acceleration, and x / y offset geometry.

[0045] As disclosed herein, the use of the first radar pair 120a or the second radar pair 120b enables capture of at least some of the various interferometric metrics to accurately determine the location of a target (e.g., a space object, a satellite) within the beam from the respective 1D phased arrays reflected by the respective trough reflectors 108. Figure 32 shows a sample configuration of receive channels. Here, the TxRx trough reflector 108 (large) is sub-digitized into groups of four (black dots). Note that the RxRx trough reflector 108 (small) has a single channel (blue dot). The RxRx trough reflector 108 is separated from the TxRx trough reflector 108 in the perpendicular direction, and such an arrangement provides a unique interference baseline that provides sensitivity to target placement in the y direction. Subsampling the aperture of the TxRx trough reflector 108 provides sensitivity to target placement in the x direction.

[0046] The separation of the trough reflectors 108 is selected to create a clear image of the target location. If the trough reflectors 108 are spaced too far apart, resolution will increase, but grating lobes will provide ambiguity to the target location. By adding more RxRx trough reflectors 108, it is possible to achieve both greater accuracy and clearer location information.

[0047] As shown in Figure 33, the data from the sub-channels are combined to form an interferometric estimate of the target placement within the beam. Generally, the main goal is to convert a single set of time series from several independent data channels into optimal range, radial velocity, radial acceleration, and x / y offset placement (relative to the nominal beam center). Per-channel phase residuals and per-channel optimal signal levels are also generated. The per-channel values ​​are useful for evaluating and updating the phase calibration.

[0048] As shown in Figures 32-33, a key input to the process is the initial detection of the target. Target data is identified by a standard (non-coherent) detection approach. Target data can also be provided by a high-fidelity state vector. The input includes estimates of range and radial velocity, so extensive searching in these dimensions is not necessary. Sources for some of these values ​​include previously performed coherent or incoherent processing, or the high-fidelity state vector. For example, the error in the input range / Doppler values ​​should be less than 1 km and 100 m / s, respectively, although this can vary as needed.

[0049] As shown in FIG. 33, the processor 134 (e.g., an interferometer processor) can be programmed to mix the time series with the nominal radial velocity and acceleration. The processor 134 can then demodulate the ranges of interest. Note that the number of ranges of interest is assumed to be less than approximately 1 km, although this can be changed as needed. The processor 134 can then filter / downsample the data. Note that this is the only downsampling stage in this module due to the small number of ranges and radial velocities of interest. The processor can then perform interpolation within the ranges. The processor 134 can then calculate the complex Fourier spectrum of each channel. The processor 134 can then fit and interpolate the ranges / velocities / accelerations to form an optimal complex visibility. The processor can then resample the visibility to a 2D UV grid and convert it to a composite image. The processor 134 can then identify peak signals in the composite image to find the optimal target placement. The processor 134 can then find the individual channel phase errors through self-calibration using the target placement and assumption of a point source.

[0050] For example, as disclosed herein, the present disclosure discloses a radar design for tracking space objects. The radar can include multiple reflectors 108, each illuminated by a 1D phased array feed 112 capable of nominally operating in the S-band frequency range. The reflectors 108 can come in pairs, one capable of transmitting and receiving (first radar) and the other capable of receiving only (second radar). This combination can measure the range, range velocity (e.g., Doppler), and two-dimensional angle of a space object passing through the field of view (FOV). The latter can use radar interferometry methods. For example, an instantiation can include at least two pairs of reflectors 108 on a given site (e.g., within a defined, zoned, or enclosed area 100). One pair 120a is oriented or directed at a set angle in one direction (e.g., 20 degrees off vertical), while the other pair 120b is oriented or directed at a set angle in another direction (e.g., 20 degrees off vertical), which may be the opposite direction. This combination allows measurements of a space object at multiple points in a single pass over the site as the space object traverses the FOV and can be used to construct an initial orbit determination (IOD) of the space object. While Figures 1-33 show several dimensions, orientations, and parameters, it should be noted that these dimensions, orientations, and parameters are exemplary and may be varied, larger or smaller, as desired.

[0051] As shown in Figures 1-33, a site-level design 100 for a radar tracking system can include a pair of radar troughs 108. The radar troughs 108 can include an array of electronic boxes 300 (or housings or containers) called octapods. Each trough 108 enables accurate measurements of the range, range-rate (e.g., Doppler), and angle of a space object. Furthermore, the radar tracking system can enable a method for estimating an angle to a target (e.g., a space object) by digitizing a group of octapods 300 within a single trough, and a method for estimating a second angle to the target by using an Rx / Rx trough and combining them to accurately estimate the target's placement within the radar beam. The radar tracking system also enables a calibration measurement system.

[0052] As shown in Figures 1-33, a site design can include two (or more or fewer) large reflectors 108 (Tx / Rx reflectors), two (or more or fewer) small reflectors 108 (Rx / Rx reflectors), a traffic control center 118 (e.g., in a shipping container or another enclosure), and cables / power plants / grounding / internet / fencing, etc. The reflectors 108 can come in pairs, i.e., one large Tx / Rx reflector 108 and a smaller Rx / Rx reflector 108. The Tx / Rx reflector 108 can transmit one circularly polarized light and receive the other. The Rx / Rx reflector 108 can receive both polarizations. The Tx / Rx system can be divided into four (or more or fewer) segments to perform interference angle measurements (top / bottom in Figure 3). The Rx / Rx system allows for angle measurements in other dimensions (left / right in Figure 3).

[0053] As shown in Figures 1-33, the reflector 108 can include a steel beam frame 106 (or another material or another metal or alloy), a plurality of aluminum (or another material or another metal or another alloy) mesh panels attached (e.g., fastened, glued, interlocked, interlocked, or bonded) to the reflector, a catwalk 110 providing access to the focus zone, and transmit and receive electronics 300 (eight arms) at the focus zone that illuminate the mesh panels.

[0054] The reflector 108 may be a parabolic trough, i.e., a cylindrical paraboloid, and may be designed to point at a particular angle (e.g., 20 degrees) from vertical, while the focusing array is oriented to point straight down toward the ground, pad, vehicle (e.g., land, sea, air), or platform in which the reflector 108 is housed. Note that the particular angle is not limited to about 20 degrees, but can be greater or less, whether vertical or non-vertical (e.g., between about 0 degrees and about 90 degrees).

[0055] For a phased array radar to operate effectively, it may be necessary to accurately calibrate the electronic and cable phase delays of some, each, many, most, or all paths. This signal calibration can be accomplished in several ways. One approach to signal calibration has some, many, most, or all of the eight arms 300 have a calibration antenna 308 on them. Various switches in the eight arms 300 allow signals to be transmitted from that antenna 308 and received at an element 302, transmitted at an element 302 and received at that antenna 308, and transmitted from one eight arm 300 to another eight arm 300. Additionally, signals can be looped through various parts of the RF chain to measure and calibrate phase. Another approach to signal calibration has several antennas 146 embedded in the surface of the reflector 108. Signals can be transmitted from the calibration antenna 146 and received at the eight arm elements 300, or transmitted from the eight arms 300 and received at the calibration antenna 146 to measure phase and amplitude. This configuration / technique, combined with a theoretical model of the phased array, can be used to calibrate the phased array. Yet another approach to signal calibration is to have a calibration antenna in the far field of up to eight elements of the array, although more or less is possible. Thus, the calibration antenna can be used to measure the beam pattern of the eight-arm 300 or overlapping elements of the eight-arm 300. An adaptive beamforming approach can be implemented that adjusts the beam pattern to best fit a theoretical model of the gain pattern. This approach only allows for the signal strength to be utilized, not the phase of the resulting pattern.

[0056] At a given site, there may be many (more than two) pairs of reflectors 108, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, tens, hundreds, thousands, or even more, including all intermediate values ​​therein. Additionally, there may be multiple Rx / Rx troughs 108 for a given Tx / Rx trough (e.g., a many-to-one correspondence). For example, there may be at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, tens, hundreds, thousands, or even more, including all intermediate values ​​therein. These Rx / Rx 108 may be positioned adjacent to or around a given Tx / Rx 108, whether feet, yards, or miles apart, depending on the desired angle. These Rx / Rx 108 can also be arranged in a line (e.g., train style) in sequence or consecutively, or in a closed (e.g., O, D, P) or open (e.g., U, C, J, S, L) configuration relative to the Tx / Rx.

[0057] As shown in FIGS. 1-33, a system may include a frame 106, a reflector 108 supported via the frame 106, a catwalk 110 extending above the reflector 108, and a phased array 112 supported via the catwalk 110 and oriented toward the reflector 108 so as to track a space object. The frame 106 may be supported via an earth volume 102 or the ground. The frame 106 may be supported via a vehicle (e.g., land, sea, or airborne). The frame 106 may be supported via an ocean platform, including any body of water platform. The phased array 112 is a 1D phased array. The phased array 112 may operate in the S-band frequency range. The phased array 112 may be oriented toward the ground. The phased array 112 may transmit multiple first signals via the reflector 108 and receive multiple second signals (e.g., reflections) via the reflector 108. The phased array 112 can avoid transmitting signals through the reflector 108 and still receive signals (e.g., reflections) through the reflector 108. The reflector 108 can be a parabolic trough. The reflector 108 can be a cylindrical paraboloid. The phased array 112 and reflector 108 can be positioned such that the phased array 112 directs signals to the reflector 108, which reflects the signals at a non-perpendicular angle. The non-perpendicular angle can be between about 0 and 90 degrees, and within that range can be less than about 80 degrees, less than about 70 degrees, less than about 60 degrees, less than about 50 degrees, less than about 40 degrees, less than about 30 degrees, less than about 25 degrees, greater than about 5 degrees, greater than about 10 degrees, greater than about 15 degrees, between about 15 degrees and about 25 degrees, about 20 degrees, or the like. The phased array 112 and the reflector 108 can be positioned such that the phased array 112 directs a plurality of signals to the reflector 108, which reflects the signals at a perpendicular angle. The pad 104 can support the frame 106. The pad 106 can be positioned such that the reflector 108 extends between the pad 106 and the catwalk 110. The pad 106 can be positioned such that the reflector 108 extends between the pad 104 and the phased array 112.The shipping container 118 includes a set of logic (e.g., circuits, cables, switches, amplifiers, encoders) in control communication with the phased array 112. The pad 104 can support the shipping container 118. The phased array 112 can transmit circularly polarized light. The phased array 112 can enable measurement of an interference angle along a vertical axis, where the interference angle is associated with a space object. The phased array 112 can enable measurement of an angle along a horizontal axis, where the angle is associated with a space object. The frame 106 or the catwalk 110 can include a metal or alloy. The reflector 108 can include multiple mesh panels. At least one of the mesh panels can include a metal or alloy. The catwalk 110 or the reflector 108 can be assembled (e.g., fastened, mated, interlocked, glued) to the frame. The phased array 112 can include multiple housings 300 that are separate and distinct from one another. The housings 300 can be arranged vertically and linearly along the catwalk 110. At least one of the housings 300 can house multiple antennas 302 linearly spaced apart from one another. At least one of the antennas 302 can be a patch antenna. The housings 300 can be arranged along a catwalk so that the antennas are linearly aligned together. At least one of the housings 300 can house a calibration antenna 308. At least one of the housings 300 can house multiple patch antennas 302 and multiple switches, where the switches are coupled to the calibration antenna 308 and the patch antennas 302 such that (1) the calibration antenna 308 transmits a first signal and at least one of the patch antennas 302 receives a second signal, and (2) at least one of the patch antennas 302 transmits a third signal and the calibration antenna 308 receives a fourth signal. At least two of the housings 300 can transmit at least two signals between each other. At least one of the housings 300 loops signals through various portions of a radio frequency (RF) chain to measure or calibrate signal phase.The reflector 108 may include a trough with a surface, and the antenna 146 may be embedded in the surface. The antenna 146 may transmit a signal to the phased array 112 so that at least one of the signal's phase or signal amplitude is measured. The phased array 112 may transmit a signal to the antenna 146 so that at least one of the signal's phase or signal amplitude is measured. The catwalk 110 may be supported via A-shaped posts. For example, the catwalk 110 may span multiple A-shaped posts. The catwalk 110 may be supported via non-A-shaped posts (e.g., J-shaped, T-shaped, L-shaped, J-shaped, V-shaped, M-shaped, C-shaped, U-shaped, D-shaped). For example, the catwalk 110 may span multiple posts. Regardless of the shape, the posts may include metal, alloy, plastic, wood, rubber, or other materials. The catwalk 110 may be suspended above the reflector via multiple lines (eg, ropes, cables, chains).

[0058] 1-33, there may be a system including a radiation reflector 108 and a phased array 112 including a first housing 300 and a second housing 300. The first housing 300 may house a plurality of first patch antennas 302 facing the parabolic reflector 108, where the first patch antennas 302 are linearly spaced apart from one another. The second housing 300 may house a plurality of second patch antennas 302 facing the parabolic reflector 108, where the second patch antennas 302 are linearly spaced apart from one another. The first housing 300 may be positioned adjacent to the second housing 300 such that the first patch antennas 302 and the second patch antennas 302 are linearly aligned together to receive a plurality of signals via the parabolic reflector 108. The signals are a plurality of first signals, and the first housing 300 is positioned adjacent to the second housing 300 such that the first patch antenna 302 and the second patch antenna 302 are linearly aligned together to transmit a plurality of second signals through the parabolic reflector 108. The phased array 112 may be a 1D phased array.

[0059] 1-33, a system may include a first assembly including a first frame 106, a first reflector 108 supported via the first frame 106, a first catwalk 110 extending over the first reflector 108, and a first phased array 112 supported via the first catwalk 110 and directed toward the first reflector 108. The first phased array 112 may transmit a plurality of first signals via the first reflector 108, and the first phased array 112 may receive a plurality of second signals (e.g., reflections from a space object based on the first signals) via the first reflector 108. The system may include a second assembly including a second frame 106, a second reflector 108 supported via the second frame 106, a second catwalk 110 extending over the second reflector 108, and a second phased array 112 supported via the second catwalk 110 and directed toward the second reflector 108. The second phased array 112 does not transmit signals via the second reflector 108, and receives a plurality of third signals (e.g., reflections from space objects based on the first signals) via the second reflector 108. The first signals are transmitted in a general direction offset perpendicularly, and the second and third signals are received in a general direction offset perpendicularly.

[0060] 1-33, a system may include a first radar pair 120a including a first assembly and a second assembly. The first assembly includes a first frame 106, a first reflector 108 supported via the first frame 106, a first catwalk 110 extending over the first reflector 108, and a first phased array 112 supported via the first catwalk 110 and oriented toward the first reflector 108. The first phased array 112 transmits a plurality of first signals via the first reflector 108, and receives a plurality of second signals (e.g., reflections from space objects based on the first signals) via the first reflector 108. The second assembly includes a second frame 106, a second reflector 108 supported via the second frame 106, a second catwalk 110 extending over the second reflector 108, and a second phased array 112 supported via the second catwalk 110 and directed toward the second reflector 108. The second phased array 112 does not transmit signals via the second reflector 108, and the second phased array 112 receives a plurality of third signals (e.g., reflections from space objects based on the first signals) via the second reflector 108. The system may include a second radar pair 120b including a third assembly and a fourth assembly. The third assembly includes a third frame 106, a third reflector 108 supported via the third frame 106, a third catwalk 110 extending over the third reflector 108, and a third phased array 112 supported via the third catwalk 110 and directed toward the third reflector 108. The third phased array 112 transmits a plurality of fourth signals via the third reflector 108, and the third phased array 112 receives a plurality of fifth signals (e.g., reflections from a space object based on the fourth signals) via the third reflector 108. The fourth assembly includes a fourth frame 106, a fourth reflector 108 supported via the fourth frame 106, a fourth catwalk 110 extending over the fourth reflector 108, and a fourth phased array 112 supported via the fourth catwalk 110 and directed towards the fourth reflector 108.The fourth phased array 112 does not transmit a signal through the fourth reflector 108, and the fourth phased array 112 receives a plurality of sixth signals (e.g., reflections from space objects based on the fourth signal) through the fourth reflector 108. The system may include a defined area 110 (e.g., a fenced-in area, an enclosed area, an elevated area, a visually distinct area) that includes a first radar pair 120a and a second radar pair 120b. The first radar pair 120a is oriented off-vertically in a first direction, and the second radar pair 120b is oriented off-vertically in a second direction (e.g., different, non-overlapping, or opposite directions) to enable tracking of space objects at multiple points (e.g., a V-like configuration).

[0061] The various corresponding structures, materials, acts, and equivalents of all means or step-plus-function elements in the various claims below are intended to include any structure, material, or act for performing the function in combination with the elements of other claims as specifically claimed. The various embodiments were chosen and described in order to best explain the various principles of the disclosure and its various practical applications, and to enable others skilled in the art to understand the disclosure in various embodiments with various modifications suited to the particular uses contemplated.

[0062] This detailed description has been presented for various purposes of illustration and explanation, but is not intended to be completely exhaustive and / or to limit this disclosure to the various forms disclosed. Numerous modifications and variations in technique and structure will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure, as set forth in the various claims that follow. Accordingly, such modifications and variations are intended to be part of this disclosure. The scope of the present disclosure is defined by the various claims, including known and unforeseeable equivalents at the time of filing of this disclosure.

[0063] (Appendix 1) 1. A system comprising: A defined area; a first frame disposed within the defined region; a first trough reflector disposed within the defined area, the first trough reflector being fixed to the first frame, the first trough reflector having a first shape, a first longitudinal valley, and a first scale; a first 1D phased array disposed within the defined area, the first 1D phased array being supported by the first frame on the first trough reflector such that the first 1D phased array transmits a set of signals through the first trough reflector and receives a set of reflections based on the set of signals through the first trough reflector; a second frame disposed within the defined area; a second trough reflector disposed within the defined area, the second trough reflector fixed to the second frame, the second trough reflector having a second shape, a second longitudinal valley, and a second scale, the second shape being the first shape, the second longitudinal valley being parallel to the first longitudinal valley, and the second scale being smaller than the first scale; and a second 1D phased array disposed within the defined area, wherein the second 1D phased array is supported by the second frame on the second trough reflector such that the second 1D phased array does not transmit any signals through the second trough reflector and receives the set of reflections based on the set of signals through the second trough reflector. (Appendix 2) 10. The system of claim 1, wherein the first 1D phased array forms a first line and the second 1D phased array forms a second line, the first line being parallel to the second line. (Appendix 3) a first leg fixed to the first frame within the defined area, the first leg extending over the first trough reflector; a second leg fixed to the first frame within the defined area, the second leg extending over the second trough reflector; a platform secured to the first leg and the second leg within the defined area, the platform extending along the first longitudinal valley onto the first trough reflector, the platform housing the first 1D phased array. (Appendix 4) 2. The system of claim 1, wherein the first 1D phased array includes a set of housings positioned on the platform immediately adjacent to one another on the first trough reflector, each member of the set of housings including a set of antenna elements arranged in a row on the respective housing and facing the first trough reflector. (Appendix 5) a first leg fixed to the second frame within the defined area, the first leg extending over the second trough reflector; a second leg fixed to the second frame within the defined area, the second leg extending over the second trough reflector; a platform secured to the first leg and the second leg within the defined area, the platform extending along the second longitudinal valley onto the second trough reflector, the platform housing the second 1D phased array. (Appendix 6) 6. The system of claim 5, wherein the second 1D phased array includes a set of housings positioned on the platform immediately adjacent to one another on the second trough reflector, each member of the set of housings including a set of antenna elements arranged in a row on the respective housing and facing the second trough reflector. (Appendix 7) a container disposed within the defined area, the container spaced apart from the first frame, the first trough reflector, the first 1D phased array, the second frame, the second trough reflector, and the second 1D phased array, the container having an interior area sized for a user to walk into; 10. The system of claim 1, further comprising: logic disposed within the interior region, the logic in communication with the first 1D phased array and the second 1D phased array, such that the logic controls the first 1D phased array and the second 1D phased array. (Appendix 8) 8. The system of claim 7, wherein the logic includes a processor located within the container, a transmitter located within the container, a set of radio frequency (RF) receivers located within the container, and a network interface located within the container, the transmitter and the set of RF receivers arranged to be communicative between the processor and the network interface. (Appendix 9) 8. The system of claim 7, further comprising a signal splitter coupled to the logic and the first 1D phased array, whereby the set of signals is generated based on the signal splitter receiving a set of data from the logic and splitting the set of data. (Appendix 10) 10. The system of claim 1, wherein the first 1D phased array transmits the set of signals through the first trough reflector based on a first circular polarization and receives the set of reflections through the first trough reflector based on a second circular polarization, the first circular polarization not being identical to the second circular polarization. (Appendix 11) 11. The system of claim 10, wherein the first circular polarization is opposite to the second circular polarization. (Appendix 12) 11. The system of claim 10, wherein the second 1D phased array receives the set of reflections via the second trough reflector based on the first circular polarization and the second circular polarization. (Appendix 13) the set of signals is a first set of signals and the set of reflections is a first set of reflections; a third frame disposed within the defined area; a third trough reflector disposed within the defined area, the third trough reflector being fixed to the third frame, the third trough reflector having a third shape, a third longitudinal valley, and a third scale; and a third 1D phased array disposed within the defined area, the third 1D phased array being supported by the third frame on the third trough reflector such that the third 1D phased array transmits a second set of signals via the third trough reflector and receives a second set of reflections based on the second set of signals via the third trough reflector; and a fourth frame disposed within the defined area; a fourth trough reflector disposed within the defined area, the fourth trough reflector fixed to the fourth frame, the fourth trough reflector having a fourth shape, a fourth longitudinal valley, and a fourth scale, the fourth shape being the third shape, the fourth longitudinal valley being parallel to the third longitudinal valley, and the fourth scale being smaller than the third scale; and a fourth 1D phased array disposed within the defined area, the fourth 1D phased array being supported by the fourth frame on the fourth trough reflector such that the fourth 1D phased array does not transmit any signals via the fourth trough reflector and receives the second set of reflections based on the second set of signals via the fourth trough reflector; 2. The system of claim 1, wherein the second trough reflector is disposed between the first trough reflector and the fourth trough reflector, the fourth trough reflector is disposed between the second trough reflector and the third trough reflector, the first set of reflections form a first field of view, the second set of reflections form a second field of view, and the first field of view does not overlap with the second field of view. (Appendix 14) further comprising a processor in communication with the first 1D phased array, the second 1D phased array, the third 1D phased array, and the fourth 1D phased array, the processor comprising: 14. The system of claim 13, programmed to track an orbiting space object within the first field of view and the second field of view such that the orbiting space object can be detected from within the defined region at least twice in a single pass over the defined region. (Appendix 15) 14. The system of claim 13, wherein the second longitudinal valley is parallel to the fourth longitudinal valley. (Appendix 16) 14. The system of claim 13, wherein the first longitudinal valley is parallel to the third longitudinal valley. (Appendix 17) 14. The system of claim 13, wherein the second longitudinal valley is not parallel to the fourth longitudinal valley. (Appendix 18) 14. The system of claim 13, wherein the first longitudinal valley is not parallel to the third longitudinal valley. (Appendix 19) further comprising a processor in communication with the first 1D phased array, the second 1D phased array, the third 1D phased array, and the fourth 1D phased array, the processor comprising: causing the first 1D phased array and the second 1D phased array to detect space objects within the first field of view based on the first set of reflections; determining an initial trajectory of the space object based on the first set of reflections; After the initial orbit of the space object is determined, scheduling the third 1D phased array and the fourth 1D phased array to detect the space object; causing the third 1D phased array and the fourth 1D phased array to detect the space object within the second field of view based on the second set of reflections according to the schedule; and taking an action associated with the initial orbit in response to the space object being detected within the second field of view based on the second set of reflections in accordance with the schedule. (Appendix 20) 20. The system of claim 19, wherein the act includes modifying the initial trajectory such that a new trajectory is formed. (Appendix 21) 20. The system of claim 19, wherein the action includes keeping the initial trajectory intact. (Appendix 22) 20. The system of claim 19, wherein the act includes creating a new trajectory based on the initial trajectory. (Appendix 23) 20. The system of claim 19, wherein the processor determines the initial orbit for the space object not listed in a record of a set of records in a database remote from the processor, the set of records corresponding to a set of space objects other than the space object. (Appendix 24) 20. The system of claim 19, wherein the processor determines the initial orbit of the space object as recorded in a record in a database remote from the processor, the record lacking orbital parameters corresponding to the space object for a predetermined period of time. (Appendix 25) further comprising a processor in communication with the first 1D phased array and the second 1D phased array, the processor comprising: 10. The system of claim 1, wherein the system is programmed to perform radar interferometry based on, for a detected space object, transmitting the set of signals toward the space object via the first trough reflector, and receiving the set of reflections from the space object by the first 1D phased array via the first trough reflector and the second 1D phased array via the second trough reflector. (Appendix 26) 24. The system of claim 23, wherein the radar interferometry includes converting a set of time series from a set of independent data channels into optimal range, radial velocity, radial acceleration, and x / y offset geometry.

Claims

1. 1. A radar system comprising: a defined area; a first frame disposed within the defined region; a first trough reflector disposed within the defined area, the first trough reflector being fixed to the first frame, the first trough reflector having a first shape, a first longitudinal valley, and a first scale; a first 1D phased array disposed within the defined area, the first 1D phased array being supported by the first frame on the first trough reflector such that the first 1D phased array transmits a set of signals through the first trough reflector and receives a set of reflections based on the set of signals through the first trough reflector; a second frame positioned within the defined area; a second trough reflector disposed within the defined area, the second trough reflector fixed to the second frame, the second trough reflector having a second shape, a second longitudinal valley, and a second scale, the second shape being the first shape, the second longitudinal valley being parallel to the first longitudinal valley, and the second scale being smaller than the first scale; and a second 1D phased array disposed within the defined area, the second 1D phased array being supported by the second frame on the second trough reflector such that the second 1D phased array does not transmit any signals through the second trough reflector and receives the set of reflections based on the set of signals through the second trough reflector.

2. 10. The system of claim 1, wherein the first 1D phased array forms a first line and the second 1D phased array forms a second line, the first line being parallel to the second line.

3. a first leg fixed to the first frame within the defined area, the first leg extending over the first trough reflector; a second leg fixed to the first frame within the defined area, the second leg extending over the second trough reflector; 10. The system of claim 1, further comprising: a platform secured to the first leg and the second leg within the defined area, the platform extending along the first longitudinal valley over the first trough reflector, the platform housing the first 1D phased array.

4. 4. The system of claim 3, wherein the first 1D phased array includes a set of housings positioned on the platform immediately adjacent to one another on the first trough reflector, each member of the set of housings including a set of antenna elements arranged in a row on a respective housing and facing the first trough reflector.

5. a first leg fixed to the second frame within the defined area, the first leg extending over the second trough reflector; a second leg fixed to the second frame within the defined area, the second leg extending over the second trough reflector; 10. The system of claim 1, further comprising: a platform secured to the first leg and the second leg within the defined area, the platform extending along the second longitudinal valley onto the second trough reflector, the platform housing the second 1D phased array.

6. 6. The system of claim 5, wherein the second 1D phased array includes a set of housings positioned on the platform immediately adjacent to one another on the second trough reflector, each member of the set of housings including a set of antenna elements arranged in a row on a respective housing and facing the second trough reflector.

7. a container positioned within the defined area, the container spaced apart from the first frame, the first trough reflector, the first 1D phased array, the second frame, the second trough reflector, and the second 1D phased array, the container having an interior area sized for a user to walk into; 10. The system of claim 1, further comprising: logic disposed within said interior region, said logic in communication with said first 1D phased array and said second 1D phased array, such that said logic controls said first 1D phased array and said second 1D phased array.

8. 8. The system of claim 7, wherein the logic includes a processor located within the container, a transmitter located within the container, a set of radio frequency receivers (RF receivers) located within the container, and a network interface located within the container, the transmitter and the set of RF receivers positioned to be communicative between the processor and the network interface.

9. 8. The system of claim 7, further comprising a signal splitter coupled to the logic and the first 1D phased array, such that the set of signals is generated based on the signal splitter receiving a set of data from the logic and splitting the set of data.

10. 2. The system of claim 1, wherein the first 1D phased array transmits the set of signals through the first trough reflector based on a first circular polarization and receives the set of reflections through the first trough reflector based on a second circular polarization, the first circular polarization not being identical to the second circular polarization.

11. The system of claim 10 , wherein the first circular polarization is opposite to the second circular polarization.

12. 11. The system of claim 10, wherein the second 1D phased array receives the set of reflections via the second trough reflector based on the first circular polarization and the second circular polarization.

13. the set of signals is a first set of signals, and the set of reflections is a first set of reflections; a third frame disposed within the defined region; a third trough reflector disposed within the defined area, the third trough reflector being fixed to the third frame, the third trough reflector having a third shape, a third longitudinal valley, and a third scale; and a third 1D phased array disposed within the defined area, the third 1D phased array being supported by the third frame on the third trough reflector such that the third 1D phased array transmits a second set of signals via the third trough reflector and receives a second set of reflections based on the second set of signals via the third trough reflector; and a fourth frame disposed within the defined region; a fourth trough reflector disposed within the defined area, the fourth trough reflector fixed to the fourth frame, the fourth trough reflector having a fourth shape, a fourth longitudinal valley, and a fourth scale, the fourth shape being the third shape, the fourth longitudinal valley being parallel to the third longitudinal valley, and the fourth scale being smaller than the third scale; and a fourth 1D phased array disposed within the defined area, the fourth 1D phased array being supported by the fourth frame on the fourth trough reflector such that the fourth 1D phased array does not transmit any signals via the fourth trough reflector and receives the second set of reflections based on the second set of signals via the fourth trough reflector; 2. The system of claim 1, wherein the second trough reflector is disposed between the first trough reflector and the fourth trough reflector, and the fourth trough reflector is disposed between the second trough reflector and the third trough reflector, the first set of reflections forming a first field of view, the second set of reflections forming a second field of view, and the first field of view does not overlap with the second field of view.

14. further comprising a processor in communication with the first 1D phased array, the second 1D phased array, the third 1D phased array, and the fourth 1D phased array, the processor comprising:

14. The system of claim 13, programmed to track an orbiting space object within the first field of view and the second field of view so that the orbiting space object can be detected from within the defined area at least twice in a single pass over the defined area.

15. The system of claim 13 , wherein the second longitudinal valley is parallel to the fourth longitudinal valley.

16. The system of claim 13 , wherein the first longitudinal valley is parallel to the third longitudinal valley.

17. The system of claim 13 , wherein the second longitudinal valley is not parallel to the fourth longitudinal valley.

18. The system of claim 13 , wherein the first longitudinal valley is not parallel to the third longitudinal valley.

19. further comprising a processor in communication with the first 1D phased array, the second 1D phased array, the third 1D phased array, and the fourth 1D phased array, the processor comprising: causing the first 1D phased array and the second 1D phased array to detect space objects within the first field of view based on the first set of reflections; determining an initial trajectory of the space object based on the first set of reflections; after the initial orbit of the space object is determined, scheduling the third 1D phased array and the fourth 1D phased array to detect the space object; causing the third 1D phased array and the fourth 1D phased array to detect the space object within the second field of view based on the second set of reflections according to the schedule; and taking an action associated with the initial orbit in response to the space object being detected within the second field of view based on the second set of reflections in accordance with the schedule.

20. 20. The system of claim 19, wherein the action includes modifying the initial trajectory so that a new trajectory is formed.

21. 20. The system of claim 19, wherein the action comprises keeping the initial trajectory intact.

22. The system of claim 19 , wherein the action includes creating a new trajectory based on the initial trajectory.

23. 20. The system of claim 19, wherein the processor determines the initial orbit for the space object not listed in a record of a set of records in a database remote from the processor, the set of records corresponding to a set of space objects other than the space object.

24. 20. The system of claim 19, wherein the processor determines the initial orbit of the space object as recorded in a record in a database remote from the processor, the record lacking orbital parameters corresponding to the space object for a predetermined period of time.

25. further comprising a processor in communication with the first 1D phased array and the second 1D phased array, the processor comprising:

10. The system of claim 1, wherein the system is programmed to perform radar interferometry for a detected space object based on transmitting the set of signals toward the space object through the first trough reflector and receiving the set of reflections from the space object by the first 1D phased array through the first trough reflector and the second 1D phased array through the second trough reflector.

26. 24. The system of claim 23, wherein the radar interferometry comprises converting a set of time series from a set of independent data channels into optimal range, radial velocity, radial acceleration, and x / y offset geometry.

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