Patent Application
20230092301
The present invention relates to a broadband network and free-space optical links, and more particularly, the present invention relates to a system and method for higher capacity and coverage of broadband networks using free-space optical communications links.
Advanced over-the-air communication systems generally use Ku, Ka, and V-band microwave or radio frequencies (RF) for high-throughput internet connectivity. Terrestrial systems, however, are limited to the use of RF frequency range that provides a lesser speed of a few megabits per second. Presently, high-capacity satellite broadband systems typically require thousands of low-earth orbital (LEO) satellites and a large number of gateways. This requires a huge upfront cost, which few business entities can afford. Moreover, for increasing the capacity, the cost increases exponentially, which limits the present infrastructures to a few terabits per second. Besides the cost, the limited availability of RF spectrum is posing a different set of challenges.
Replacing RF-based gateways with optical link gateways appears to be an attractive option. However, the telecommunications industry has been hesitant to adopt optical gateways due to the huge costs of high-throughput optical terminals and the spatial diversity required to provide sufficient availability under various atmospheric conditions.
Several solutions have been proposed in the prior art, however, they fail to address one or more limitations or drawbacks. For example, U.S. Pat. No. 10,707,961B2, “Adaptive Communication System” discloses an optical communications satellite constellation that uses high-altitude pseudo satellites to make the link between the satellites and the gateways, wherein high-altitude pseudo satellites convert RF forward data streams from the gateways to optical frequencies for transmission to the satellites and convert the return optical data streams from the satellites to RF for transmission to the gateways. While this allows conventional gateways to be used, the use of RF for the “last mile” for the gateway-satellite link limits system capacity to that of an all-RF system, defeating the high-capacity benefit of the optical architecture. U.S. Pat. Nos. 9,917,646 B2, 10,320,481 B2, 10,069,565 B2, and 10,142,021 B2 envision several variants of optical satellite constellations with optical gateways. However, they all use conventional optical modulation techniques which fundamentally limit the capacity of the system and they each have additional shortcomings. U.S. Pat. No. 9,917,646 addresses a forward link design in which the user signal at its RF downlink frequency is wave-division-multiplexed onto the optical link to avoid onboard digital processing. This patent does not address how to effectively generate a high data rate RF or optical system capacity nor the method of modulation that enables a high-capacity optical system design.
U.S. Pat. No. 10,320,481 describes a method for allocating bandwidth and addressing data streams to users, then combining these signal streams via wave-division-multiplexing and up-converting them onto optical frequencies. This conventional modulation approach limits system capacity adversely. U.S. Pat. No. 10,069,565 discloses a variant of this system using on-board processing (OBP) of all signals on the satellites; while this is presented as a potential way for minimizing the number of gateways, OBP adds significant mass, power, and complexity to each satellite which dramatically increases system cost without any direct capacity benefit. Lastly, patent 10,142,021 provides a similar system, but in recognizing the prohibitive cost of digital OBP, it places the routing function in the gateway in a form of Ground-Based Beamforming (GBBF) thus predesignating the routing information into the signal stream.
The publication “Feasibility of An Optical Frequency Modulation System for Free-Space Optical Communications” by Luryi and Gouzman, International Journal of High-Speed Electronics and Systems, Vol. 16, No 2 (2006), pg. 559-566, considered an optical version of a well-known wideband frequency modulation technique that inherently has a high signal-to-noise ratio. This optical wideband frequency modulation (OWBFM) concept has not been implemented and requires the development of a rapidly tunable laser diode at the frequency appropriate to a specific application.
Thus, considering the immediate need for high-capacity broadband networks at low costs, a need is appreciated for a system and method that overcomes the aforesaid drawbacks and limitations with traditional RF-based and optical-based gateways.
The following presents a simplified summary of one or more embodiments of the present invention to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments and is intended to neither identify critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.
The principal object of the present invention is therefore directed to a system and method for higher capacity broadband networks at a lower cost.
It is another object of the present invention that both and capacity and latency of the network can be improved.
It is still another object of the present invention that the number of satellites needed can be reduced.
It is a further object of the present invention that the number of gateways needed can be reduced.
It is still a further object of the present invention that the dependence on the radio frequency spectrum can be reduced.
In one aspect, disclosed are a system, an architecture, and method for the provision of terrestrial point-to-point, high-altitude platform, and satellite broadband data services by using a free-space optical communications link in conjunction with an extremely-high-data-rate (EHDR) wideband frequency modulation waveform. The invention supports high data capacities, greater than an order of magnitude over current point-to-point optical communication systems for both earth and outer space applications as well as over the most capable Low Earth Orbit (LEO) satellite constellation being envisioned and deployed in the 2020-2025 timeframe. To achieve these exceptional capacities at a conventional cost, the disclosed system, architecture, and method use wideband frequency modulated (WBFM) optical links that permit the use of compact optical terminals. For terrestrial applications, the system, architecture, and method additionally can implement high altitude relay platforms (HARPs) for better availability and longer distance coverage. For space applications, the system, architecture, and method use space-fed lens satellite Radio Frequency (RF) antennas that generate multiple beams, a novel frequency conversion scheme for compact accommodation on small satellites, overlapping ground coverage from multiple satellites, and high-altitude relay platforms (HARPs) to relay signals between satellites and the gateways. The disclosed system allows standard, available satellite user terminals to be used since conventional Ku-band and Ka-band RF links are used for user communications links. The disclosed system and method also enable high-capacity terrestrial, planetary, and outer space communications systems.
In one aspect, the disclosed system, method, and architecture allow for an unconventional combination of technical and architectural features that synergistically enables high system data capacities in satellite constellations, far greater than that of prior art system concepts. These enabling features include (1) incorporating high data rate modulation technique i.e., wide-band frequency modulation (OWBFM), to aggregate constellation data streams into those satellites in view of and communicating with the gateways, (2) using an all-optical satellite-to-gateway and satellite-to-satellite architecture, (3) limiting the gateways to a minimal number, located in areas with historically proven clearest sky conditions, (4) capitalizing on WBFM's inherently high signal-to-noise ratio so that high capacity data can be optically transmitted at modest power levels and thus with low-power, cost-effective satellites, (5) modulating user RF data directly onto the optical carriers without digital on-board processing and routing on the satellites, thus avoiding significant satellite mass, power and cost penalties, and (6) incorporating a novel RF beamforming technique that enables forming a large number of beams per satellite using antennas of modest size and therefore enabling smaller, cost-effective satellites to be used. Each of the above features alone does not increase the capacity significantly, but the disclosed implementation provides a significant increase in the total data rate throughput of a satellite system. In addition, elements of the architecture may be used to significantly increase data rate capacity in certain terrestrial applications where free-space optical communications are desirable for geographical, infrastructure, and/or security reasons, as well as in lunar, planetary, and outer space applications.
In one aspect, the disclosed system and method can attain high-capacity satellite system communications where broadband services are needed continuously across the moon's surface, across planetary surfaces, from and to Lagrange points, and between other outer space communication points. For this type of application, the satellite system communicates directly to user terminals and gateway terminals in orbit and/or on the lunar or planet surface.
In one aspect, the disclosed system and method can attain high capacity over-the-air point-to-point terrestrial communication service including ship-to-ship communications. OWBFM can be used to efficiently increase the data rate for a given application's terminal size and power. The capacity and coverage can be further enhanced by using HARPs to achieve greater communications and point-to-point distances from and to a given terminal. If used, the HARPs can utilize a “bent pipe” analog architecture versus a digital architecture to avoid digital processing's higher complexity, mass, and power.
In one aspect, disclosed is a high-capacity communication system incorporating several features applied to increase data service capacity cost-effectively and dramatically for both microwave satellite links to user terminals and free-space point-to-point communication solutions. Both solutions are served through a number of common synergistic features: A high-capacity optical waveform wherein multiple RF baseband carriers, after adaptive coding digital modulation (ACM), are wide-band frequency modulated into optical data streams which then are Wavelength Division Multiplexed (WDM) onto optical beams for transmission; and A “bent pipe” analog communications architecture to avoid the complexity, mass, power, and cost of analog-to-digital and digital-to-analog conversion;
Terrestrial, lunar, planetary and outer space applications are further achieved through the following synergistic features: the use of terrestrial optical terminals (TOTs) providing point-to-point service to access the Internet backbone, users, and/or RF microwave towers for local RF distribution to users; and sufficient spatially isolated optical terminals at each communication point to maintain links with other communication points, HARPs, drones, or satellites in view via multiple optical beams. In terrestrial applications, TOTs are optionally supported with HARPs or drones to extend the transmission range or to provide communication path redundancy. Such TOT architectures can also be adapted for use on surfaces of other celestial bodies such as the Moon and Mars as well as free-flying space vehicles.
In one aspect, a high-capacity satellite system is achieved through the following synergistic features: A high-altitude Low Earth Orbit (LEO) satellite constellation, such as a Walker-Delta configuration, that provides full-earth coverage by both ascending and descending satellites; Optical gateways (OGWs) placed in locations with historically minimal cloud coverage in the northern and southern hemispheres and connected by high-capacity fiber to global Internet data trunk networks; Optical communication links between gateways and satellites, including via relay systems used to mitigate link disturbance due to atmospheric phenomena and to support capacity maximization; Sufficient spatially isolated optical terminal clusters, and terminals within those clusters, within each OGW installation to communicate with all satellites in view via multiple optical beams per satellite; Optical inter-satellite links to enable data routing, via other satellites, from (to) satellites out of view of an open OGW to (from) satellites in view of an open OGW; Switching RF user communication bands and/or polarizations when satellites reach their maximum latitudes in the polar regions to provide simultaneous full earth coverage by user beams, provided by ascending satellites in one RF band/polarization and by descending satellites in another RF band/polarization, while avoiding crossing plane interference; Providing a large number of RF user beams in both bands and/or polarizations by the use of space-fed lens multibeam phased array antennas onboard each satellite; Conducting the beamforming in the space-fed lens antennas at a high RF millimeter wave frequency to reduce antenna volume and thereby enable efficient accommodation of as many as four such antennas on each of the small satellites; Corporate (i.e., as one body) scanning of all RF beams produced by the space fed lens antennas in order to compensate for the orbital motion of each satellite and provide beam dwell times of minutes, after which a fast constellation-wide raster scan hands each ground coverage area over to the next following satellite; An RF user beam coverage footprint that overlaps with those of several adjacent (in and out of plane) spacecraft, providing multiple spatially-isolated overlapping beams, thus multiplying bandwidth available to users; A capability to begin global operations with a one-quarter subset of a full constellation which provides continuous, but not yet overlapping Earth coverage by both ascending and descending satellites; To increase capacity, accessibility, and effective availability of the OGWs and limit their number and cost, using the use of high-altitude relay platforms (HARPS) flying over OGWs to relay optical signals from and to satellites that are or may be subject to signal interference by clouds or turbulence and those that are at low elevation and thus at greater risk of atmospheric interference if using direct OGW links; Compatibility with most terrestrial customer premise equipment (CPE) for current and planned commercial, military, and space exploration systems, supporting an easy transition for satellite internet users to this new system. The foregoing enumerated features enable a method and system employing optical links using an extremely-high-data-rate (EHDR) waveform in combination with miniaturized space-fed lens satellite RF antennas that generate many user beams while using a novel frequency conversion scheme to fit on small satellites, as well as overlapping ground coverage from multiple satellites at multiple radio frequency ranges or polarizations, leading to unprecedented bandwidth available to satellite users.
The aggregate user data rates for the disclosed system exceed those of current single-band (Ku or Ka-band) systems by at least a factor of up to 30, comprising of factor 2 for the ability to use two RF bands, a factor 4 for the overlapping coverage, and another factor 4 to 5 due to the many user beams per satellite-enabled in part by the compact antenna form factor. Individual users can select a data rate service level appropriate to their needs by choosing how many satellites they wish to access, in one or both RF bands and/or polarizations, from the overlapping coverages.
A clear understanding of the key features of the invention summarized above may be had by reference to the appended drawings, which illustrate the method and system of the invention by using an example case, although it will be understood that such drawings depict exemplary embodiments of the invention and, therefore, are not to be considered as limiting the scope of this invention which clearly contemplates the tailoring of embodiments to specific implementation objectives, constraints, and parameters. Accordingly:
Subject matter will now be described more fully hereinafter. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any exemplary embodiments set forth herein; exemplary embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, the subject matter may be embodied as apparatus and methods of use thereof. The following detailed description is, therefore, not intended to be taken in a limiting sense.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments of the present invention” does not require that all embodiments of the invention include the discussed feature, advantage, or mode of operation.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The following detailed description includes the best currently contemplated mode or modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention will be best defined by the allowed claims of any resulting patent.
The following detailed description is described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, specific details may be set forth in order to provide a thorough understanding of the subject innovation. It may be evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, well-known structures and apparatus are shown in block diagram form in order to facilitate describing the subject innovation.
The following detailed descriptions represent exemplary embodiments of the invention. Parameters may be modified to meet specific objectives of the implementation without departing from the essential scope of this invention.
An example satellite constellation, shown in
Ascending parts 120 and descending parts 121 of the orbits are both used for user communications but employ different RF bands or polarizations to avoid crossing plane interference. Satellites traversing the sparsely populated high latitudes, where user traffic is light or absent, are in a position to switch RF bands or polarizations. Users can see one ascending and one descending satellite with the initial 400 satellite constellation, and four ascending and four descending satellites with the full 1600 satellite constellation.
In addition, the main function of a satellite changes through each orbit as a function of the character of the part of the Earth in the satellite's ground coverage. Satellites over highly populated areas i.e., with a high density of users, will primarily provide user service and feed their optical signals to other satellites. On the other hand, satellites over oceans and sparsely populated areas will primarily perform an optical network relay function. Satellites within view of an OGW will predominantly function to connect aggregated satellite network traffic to the ground.
Considering factors such as latency, accessibility, ease of fiber trunk routing, security, and atmospheric turbulence, the example constellation prioritizes low-cloud, high availability, locations for OGW sites.
In addition, more specific siting within these and/or similar regions will be influenced by the degree of prevalence of clear-sky atmospheric turbulence which can interfere with the direction and noise characteristics of optical beams. Such turbulence is in part influenced by prevailing wind patterns and ground features and considering it in OGW siting can help minimize its potential impacts on optical communications performance. Furthermore, the specific siting of an OGW in these or other areas will be influenced by accessibility, terrain, security, availability of resources, and ease of fiber trunk routing to a major internet node.
The OTCs include multiple optical transmit and receive terminals that each communicate with a satellite within the appropriate elevation angle 560 and 562 of the OGW region. The number of operating OTCs will be at least equal to the number of optical spatially isolated beams transmitted and received from a single spacecraft, which is four in the example of
To facilitate the optical signal acquisition, all-optical terminals will transmit wide beacon beams parallel to the narrow fine-tracking beacon and receive and transmit communication beams. Similarly, they are equipped to receive the acquisition and fine-tracking beacons emitted by the satellite laser terminals. The OTCs are connected to the OGW processing facility 528 by optical fiber links 534.
Transmit and receive beams (552 and 554) are shown going to and from multiple satellites, for example, 502 and 504, from and to the OTCs. Each satellite has multiple optical terminals to either transmit to the OGW or adjacent satellites via crosslink transmit and receive beams, for example, beams 542 and 544 between satellites 504 and 508 and beams 546 and 548 between satellites 502 and 506. This enables satellites 506 and 508 to communicate with the OGW via satellites 502 and 504, respectively.
To provide maximum capacity and optical path diversity, high-altitude relay platforms (HARPs) 570, 572, 574, and 576 are used to communicate between OTCs 520, 522, 524, and 526, and a satellite 508 which is below the minimum elevation angle acceptable to the OTCs. In this example, optical crosslinks 579 are used to relay the communication between satellite 508 and the HARPs and from there via beams 556 to the OTCs. This significantly increases data transmission to and from the OGW by giving the OGW access to satellites that are at very low elevation angles but that can readily establish a link to the HARPs as those are operating above 90% of the earth's atmosphere. HARPs are also used by satellites that have acceptable elevation but cannot access the OGW directly due to clouds or severe atmospheric disturbances. In OGW regions and/or conditions where atmospheric turbulence is common and/or severe, HARPs can be used as routine intermediary relays for all communications between satellites and the OGW. Each HARP is functionally an upper-atmosphere extension of a specific OTC.
OTC aperture size may also be varied to optimize each OGW site's availability. This is an element of the investment and operational cost tradeoffs between satellite optical terminal power, satellite and OTC optical telescope sizes, and the extent of the use of high-altitude relay platforms as an intermediate relay to reduce the risk of optical link disruption due to atmospheric effects. Overall assessment, design, and optimization of the optical links will take into account the various loss factors such as atmospheric absorption, optics imperfections, beam wander due to turbulence, scintillation and jitter, and wavefront phase error.
An OGW operations region 530 need not be a single contiguous land area but can be a distributed installation joined together by optical fiber links. OTCs will be distributed so they are separated by a sufficient distance to ensure sufficient spatial isolation for optical beams between the OTCs and any satellite while accounting for the steering precision and resolution of the satellite optical heads. In addition, each optical terminal cluster itself is further distributed (not detailed in
The phenomenon of atmospheric turbulence is mitigated via a combination of predictive and real-time measures. Predictive selection of a satellite-OTC link path for each satellite pass is based on the characterization of historical turbulence patterns correlated with seasonal-, diurnal-, and weather-driven upper-atmosphere conditions, and refined based on link performance from just-completed passes by other satellites. When significant turbulence is likely, signals can be relayed via HARPs to the OTCs or via other satellites to another OGW. Real-time measures include a fast-steering mirror (FSM) within the optical terminal assemblies to steer out any moderate-frequency beam wander due to turbulence and other atmospheric effects.
The satellite optical repeater design between optical terminals 718 and 720 is shown in
An optical transmit beam consists of multiple frequency/wavelength division multiplexed laser beams illuminating the optics of a telescope from a single optical feed (fiber) at the focal point of the telescope. Each wavelength in the laser beam will be wide-band frequency modulated (WBFM) by baseband (low intermediate frequencies) consisting of multiple Frequency Division Multiplexed (FDM) channels containing DVB S2 or similar Adaptive Coding and Modulation (ACM) modulated carriers for the forward links.
In the case of satellite microwave transmission, the forward channel carrier is destined to be transmitted on a downlink beam to a user terminal on the Earth. Each ACM downlink carrier is time-division multiplexed to the individual user with modulation and coding (data rate) appropriate to the user's currently reported link condition (signal-to-noise ratio).
As shown in
The satellite forward-link communication signal from the optical terminal fiber couplers (item 726 in
Fiber couplers 726 are used to sample four (or n) fibers connecting four (or n) inputs to four output optical terminals for the OGW links. An n:1 fiber optic switch 1004 selects one of four (or n) paths (or fibers) 1002 to convert the signal into a single optical beam (fiber) with, for example, 12 of 25 (for 132 or 12 times 11 channels of downlink microwave beams) carriers/wavelengths 1006.
Optical carriers (λ) are then demultiplexed 1008 from the fiber 1006 into a set of optical carriers 1010. Each carrier (1 of n1) is sent through a frequency converter 1015 using tunable lasers feeding optical mixers to select embedded channels, along with heterodyne detection to convert the optical channels into millimeter wave WBFM carriers or channels 1016 in the millimeter frequency range. The WBFM signals are then demodulated 1018 into multichannel microwave baseband channels within each (1 of n3) microwave carrier 1020. Baseband channels that contain configuration commands for the antennas are diverted 1024 to the spacecraft processor. After demodulation, the channels are power split 1022 into even-odd channels that are distributed 1028 to one or more satellite RF antennas consisting in this example of a beamformer (1048 and 1050) and an output stage (1052 and 1054) including down-conversion to the proper RF frequencies, amplification, and radiating elements for transmission to users on the ground.
The baseband stream of channels 1110 is power divided into three copies, each of which is frequency shifted to millimeter bands as shown in
Each filter, for example, 1148 outputs the channel for which it is tuned to a transmission line, for example, 1149 and the none-selected channels continue to a termination. The 11 individual channel outputs of four colors are then sent to the beam inputs 1632 of the frequency-scaled forward downlink beamformer. This process is applied to all outputs from the wideband FM optical demodulators.
For the return path,
The satellite return-link communication signal path from the satellite RF antenna to the optical terminal fiber couplers (item 728 in
The baseband is composed of a number of sets of beam channels, with each set converted to a frequency range as illustrated in
The user beam coverage is illustrated in
User 1401 on the ground receives coverage, for example in the Ku band, from satellite 1411 for 6 minutes until the handoff to satellite 1415. However, user 1401 also has coverage from descending satellites, not shown, which are communicating, in this example, in the Ka-band. This provides a doubling of bandwidth available to user 1401 over conventional, non-optical systems which reserve the alternate RF band for OGW feeder link operations.
As illustrated in
These channels 1632 are then processed through a series of amplifiers 1626 and then go through a series of bandpass filters 1624 and then to a plane of elements at the input 1618 of the BFN 1630. Item 1620 represents the cylindrical anechoic absorber for the BFN where the dashed lines indicate the absorbing surface. Within the BFN 1630, the emissions from the radiating elements 1618 are absorbed by beam receive elements located at the end of the BFN 1616 chamber on the paraboloidal surface 1622. Key to the ability to scan the earth with the phased array as the satellite moves is the requirement that the electrical path lengths 1612 from each receive element 1616 to each associated transmit element 1602 through each variable amplitude and phase adjuster (VAP) element 1608 be the same. Command inputs 1610 are received by the VAPs from the spacecraft scan processor 1634 based upon constellation orbital data provided from the spacecraft telemetry system 1636. The scan processor 1634 determines how the signals are to be translated from the VAPs to the radiating elements 1602 arranged on the phased array element surface 1622 within the BFN 1630. The signals pass through a mixer 1606 where the millimeter band is received and then converted to the band required for the Ku- or Ka-band phased array. The channels then go through a series of power amplifiers 1604 before going to the feed elements 1602 of the K-band phased array transmit surface.
Similar to the forward (transmit) BFN, the return (receive) BFN operates at a higher frequency than the received RF frequency. This results in a very compact form factor for the BFN assembly, which facilitates fitting a space-fed lens on a small satellite. Before beamforming, the individual beams are upconverted from the receive frequencies to the BFN operating frequencies. In addition, the use of the same BFN operation frequencies for both forward and return BFNs and in both Ku and Ka-band antennas enables significant hardware commonality between the four RF antennas on the spacecraft for cost-effective production and accommodation.
A third communications overlay approach is to use another microwave tower 644 co-located and connected 642 to the TOT 620 near the internet cloud 626 to receive and transmit to the other microwave tower 634 via RF 646. A fourth communication overlay approach is to use the HARPs system to relay between the remote TOTs and satellites 612 and 648 to enable cloud-free access to TOTs with direct internet access. A fifth communication overlay approach is to use a satellite 628 to access a TOT 620 through an optical communications link 632 and then use a satellite RF communications link 650 to communicate with the user terminal 638.
The above-described OWBFM communications architecture may also be advantageously applied to airborne drones serving as the source of high volumes of data to be transmitted or relayed to ground locations or as the destination for short-range redistribution of data to users on the ground. Similarly, the OWBFM architecture may be advantageously applied to ship-to-ship, ship-to-shore, and shore-to-ship communications. In each of these applications, the physical configuration of the architecture will be tailored to the specific performance requirements and operating environments of that application. This will involve, for example, the optical terminal sizing, quantity, power provisions, physical arrangement, axes and range of articulation, and provisions for operating them under the unique environmental conditions of each application.
Elements of the disclosed architecture can be applied advantageously to other space-to-space and space-to-ground communication needs. As lunar and planetary exploration proceeds, EHDR long-distance point-to-point communications on the surface of the Moon and Mars, for example, can be expeditiously established by locating a small number of optical WBFM stations on crater rims and other high-altitude sites, without the need for relay overlays due to the absence of an interfering atmosphere. In these applications, the physical configuration of the architecture will be tailored with regard to, for example, optical terminal sizing, quantity, power provisions, physical arrangement, axes and range of articulation, and provisions for operating them under the applicable environmental conditions.
Additionally, elements of the disclosed architecture can provide EHDR space-to-ground and ground-to-space communications can be supported by optical gateways, assisted by HARPs as appropriate, to communicate with deep-space spacecraft in transit to planetary destinations or orbiting the Moon, Mars, or other planets, or located on or orbiting any Lagrange point, with the implementation tailored to the specific requirements and environments.
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above-described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed.
This application claims priority from a U.S. Provisional Patent Application Ser. No. 63/246,473, filed on Sep. 21, 2021, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63246473 | Sep 2021 | US |
