Burrington's satellite subjects aren't random—like the work of Trevor Paglen, her images envision data centers, military sites, and downlinks.
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They're set up in such a way that allows them to process and deliver imagery to their customers in real time as soon as one of their satellites downlinks new data.
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In his sprawling desert retreat outside the capital of Riyadh, satellite downlinks assure CNBC is visible as he welcomes guests to lavish feasts laid out on carpets scattered across the sands.
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The 90-seat Noble Planetarium also features an exhibit area that provides large screens with views of the Sun, as well as downlinks offering information from the Hubble Telescope.
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This extreme altitude is critical due to the amount of charged-particle interference that would occur while taking measurements within the magnetosphere. When within the magnetosphere of the Earth (), the satellite also performs other functions, including telemetry downlinks.
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Flight Operations consists of the direct support and monitoring of HST functions in real-time. Real-time daily flight operations for HST include about 4 command load uplinks, about 10 data downlinks, and near continuous health and safety monitoring of the observatory. Real-time operations are staffed around the clock. Flight operations activities for HST are done at NASA's GSFC in Greenbelt, Maryland.
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Using professional grade hardware or modified consumer grade hardware it is possible to operate on 802.11b/g hardware on channels that are effectively: "−1" at 2.402 GHz, and "−2" at 2.397 GHz. Using these channels allows amateur operators to move away from unlicensed Part 15 operators but may interfere with amateur radio satellite downlinks near 2.400 GHz and 2.401 GHz.
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It downlinks telemetry data by radio to mission control. The FDD displays data from the SNU on a color LCD. It has several distinct display modes for different phases of flight, including the boost phase, coast, reentry, and gliding. The FDD is particularly important to the pilot during the boost and coast phase in order to "turn the corner" and null rates caused by asymmetric thrust.
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FDMA is one of the multiple access methods used in cellular networks. 50 MHz blocks of communication channel are assigned, which lie in radio frequency range and contain an equal number of uplinks (terminal to base station) and downlinks (base station to terminal). One or more bidirectional channels are carried by 10-90 band pairs. The digital networks additionally make use of either CDMA or TDMA methods.
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The Saeghe-2 has more advanced avionics, with tele-command and telemetry uplinks and downlinks between the drone and the ground control station. The Saeghe 2 also has GPS navigation it can use to follow navigational points on autopilot beyond the line-of-sight of the operator. The Saeghe-2 shares the same airframe as the Saeghe-1. The Saeghe 2 carries a gyrostabilized radar reflector and three IR flares.
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This network technology is supposed to ultimately enable missions that involve multiple spacecraft where reliable inter-vessel communication might take precedence over vessel-to-earth downlinks. According to a February 2011 statement by Google's Vint Cerf, the so-called "Bundle protocols" have been uploaded to NASA's EPOXI mission spacecraft (which is in orbit around the Sun) and communication with Earth has been tested at a distance of approximately 80 light seconds.
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Clifford, Walker (2012-02), UNDERSTANDING THE CONCEPT OF FTTO (FIBER TO THE OFFICE/OUTLET). Retrieved 2016-07-13 The FTTO switch provides a connection between optical uplinks and electrical downlinks. Typically, the switch has up to five twisted pair ports supporting Power over Ethernet (IEEE 802.3af, 15.4W per Port) and Power over Ethernet Plus (IEEE 802.3at, 30W per Port). Modern FTTO Switches offer speeds of 1 Gbit/s per user port (Gigabit Ethernet).
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Scheme of the architecture for the planned Deep Space Optical Communications (DSOC) prototype Deep Space Optical Communications (DSOC) is a laser space communication system in development meant to improve communications performance 10 to 100 times over the current radio frequency technology without incurring increases in mass, volume or power.Deep Space Optical Communications (DSOC). Jennifer Harbaugh, NASA News 24 October 2017. DSOC will be capable of providing high bandwidth downlinks from beyond cislunar space.
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The PHY layer must be able to adapt to different conditions and also needs to be flexible for jumping from channel to channel without errors in transmission or losing clients (CPEs). This flexibility is also required for being able to dynamically adjust the bandwidth, modulation and coding schemes. OFDMA will be the modulation scheme for transmission in up and downlinks. With OFDMA it will be possible to achieve this fast adaptation needed for the BS's and CPEs.
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For certain phase modulation (PM) downlinks, the uplink to downlink frequency ratio was exactly 221/240, with a coherent transponders used. A phase locked loop on the spacecraft multiplied the uplink carrier frequency by 240/221 to produce the downlink carrier frequency. A local oscillator produced the downlink carrier if the uplink was not available. This "two-way" technique allowed velocity measurements with a precision on the order of centimeters/second, by observing the Doppler shift of the downlink carrier.
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The International Telecommunication Union allocates 76.0 GHz to 81.0 GHz to amateur radio, amateur satellites, radio astronomy and radiolocation (radar) and space research downlinks. Amateurs operate on a primary basis between 77.5 GHz and 78.0 GHz and on a secondary basis in the rest of the band. Also, 81.0 GHz to 81.5 GHz is allocated by ITU footnote 5.561A to the amateur and amateur- satellite services on a secondary basis. The ITU's allocations are the same in all three ITU regions.
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AMSAT-OSCAR 51 or AO-51 is the in-orbit name designation of a now defunct (following battery failure) LEO amateur radio satellite of the OSCAR series; formerly known as ECHO, built by AMSAT. It was launched on June 29, 2004 from Baikonur Cosmodrome, Kazakhstan on a Dnepr launch vehicle. It is in sun synchronous low Earth orbit. AO-51 contained an FM repeater with both 144 MHz (VHF) and 1.2 GHz (L band) uplinks and 435 MHz (UHF) and 2.4 GHz (S band) downlinks.
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The 5 Gbit/s rate was added to accommodate so implementation specific speeds supported by certain FPGAs. The specification also provides for non-standard link rates for bi- directional return path for applications such as camera control where high speed video links are not required. Compression and Encryption: ARINC 818 was originally envisioned as carrying only uncompressed video and audio. Applications such as high-resolution sensors, UAV/UAS with bandwidth limited downlinks, and data only applications drove the need to compress and/or encrypt a link.
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The Alaska Satellite Facility provides production, archiving and distribution to the scientific community of SAR data products and tools from active and past missions, including the June 2013 release of newly processed, 35-year-old Seasat SAR imagery. CSTARS downlinks and processes SAR data (as well as other data) from a variety of satellites and supports the University of Miami Rosenstiel School of Marine and Atmospheric Science. CSTARS also supports disaster relief operations, oceanographic and meteorological research, and port and maritime security research projects.
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Polarization-division multiplexing (PDM) is a physical layer method for multiplexing signals carried on electromagnetic waves, allowing two channels of information to be transmitted on the same carrier frequency by using waves of two orthogonal polarization states. It is used in microwave links such as satellite television downlinks to double the bandwidth by using two orthogonally polarized feed antennas in satellite dishes. It is also used in fiber optic communication by transmitting separate left and right circularly polarized light beams through the same optical fiber.
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The Internet connection provided by SES Broadband for Maritime is a two-way satellite link between the user’s vessel and the Astra 3B communications satellite at 23.5° east, which in turn is linked to the SES Broadband Services HQ and teleport located in Betzdorf where a hub connects to the Internet backbone. Downlinks and uplinks to & from the vessel's antenna comprise IP data embedded in a DVB-S2 carrier using the Ku band (10.70 GHz ~ 12.75 GHz for downlink, 14.00 GHz ~ 14.50 GHz for uplink).
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From 5% to 20% of rain fade or satellite signal attenuation may also be caused by rain, snow, or ice on the uplink or downlink antenna reflector, radome, or feed horn. Rain fade is not limited to satellite uplinks or downlinks, as it can also affect terrestrial point-to-point microwave links (those on the earth's surface). Rain fade is usually estimated experimentally and also can be calculated theoretically using scattering theory of rain drops. Raindrop size distribution (DSD) is an important consideration for studying rain fade characteristics.
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A number of functions and departments move to the MediaCityUK complex in Salford, Greater Manchester. Opens one of the largest Teleports in the UK. Currently broadcasts 80 hours of television for the betting shop industry every day from its facilities in MediaCityUK and also duplicated from its Milton Keynes base, together with the various satellite downlinks and uplinks for broadcasters around the world including European Tour Golf, Asian Tour Golf, BBC, ITV, ITN, Channel 4, Intelsat, British Sky Broadcasting – Sky News, Sky Sports, Sky Arabia & RRSat in Israel.
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AISSat-1 is a satellite used to receive Automatic Identification System (AIS) signals. Launched on 12 June 2010 from Satish Dhawan Space Center as a secondary payload, AISSat-1 is in a sun-synchronous low-Earth orbit. Initially a development project, the satellite has since passed into ordinary operations. Via downlinks at Svalbard Satellite Station and at Vardø Vessel Traffic Service Centre it tracks vessels in the Norwegian Sea and Barents Sea for the Norwegian Coastal Administration, the Norwegian Coast Guard, the Norwegian Directorate of Fisheries and other public agencies.
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The Media and Computer Services Department in Lied Library provides viewing and listening capabilities for the media collection via an integrated video network system (Safari). This system allows the delivery of analog and digital media to library carrels, preview rooms, multimedia PCs, library classrooms, and conference rooms. The media distribution system is currently equipped to play back VHS, DVDs, CDs, audio cassettes and selected cable channels, and to receive satellite downlinks. This system frees the user from having to move from machine to machine and from physically handling all the equipment and materials, and it links beyond Lied Library and connects with selected branch libraries, conference rooms, and campus classrooms.
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A typical Teledesic satellite design Teledesic was a company founded in the 1990s to build a commercial broadband satellite internet constellation. Using low-Earth-orbiting satellites small antennas could be used to provide uplinks of as much as 100 Mbit/s and downlinks of up to 720 Mbit/s. The original 1994 proposal was extremely ambitious, costing over 9 billion USD and originally planning 840 active satellites with in-orbit spares at an altitude of 700 km.In the Matter of Teledesic Corporation: Application for Authority to Construct, Launch, and Operate a Low Earth Orbit Satellite System in the Domestic and International Fixed Satellite Service.
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The communications C band was the first frequency band that was allocated for commercial telecommunications via satellites. The same frequencies were already in use for terrestrial microwave radio relay chains. Nearly all C-band communication satellites use the band of frequencies from 3.7 to 4.2 GHz for their downlinks, and the band of frequencies from 5.925 to 6.425 GHz for their uplinks. Note that by using the band from 3.7 to 4.0 GHz, this C band overlaps somewhat into the IEEE S band for radars. The C-band communication satellites typically have 24 radio transponders spaced 20 MHz apart, but with the adjacent transponders on opposite polarizations such that transponders on the _same_ polarization are always 40 MHz apart.
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Communications satellites' orbital positions are normally spaced apart along the geostationary orbit to provide for frequency reuse for both uplink and downlink transmissions. By separating adjacent satellites by a distance greater than the at-orbit beamwidth of the uplink antennas, the same carrier frequencies can be used to uplink to both satellites without interference. Similarly, a sufficient separation so that the beamwidth of the receiving dishes on the ground can distinguish one satellite from its neighbours, allows the same frequency spectrum to be used for adjacent satellite downlinks. Communications satellites are positioned in orbital 'slots' allocated under international treaty by the ITU and a separation between slots of 2° or 3° of orbital longitude is common.
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Hubble data was initially stored on the spacecraft. When launched, the storage facilities were old-fashioned reel-to-reel tape recorders, but these were replaced by solid state data storage facilities during servicing missions2 and 3A. About twice daily, the Hubble Space Telescope radios data to a satellite in the geosynchronous Tracking and Data Relay Satellite System (TDRSS), which then downlinks the science data to one of two 60-foot (18-meter) diameter high-gain microwave antennas located at the White Sands Test Facility in White Sands, New Mexico. From there they are sent to the Space Telescope Operations Control Center at Goddard Space Flight Center, and finally to the Space Telescope Science Institute for archiving.
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Adverse weather conditions, restrictions placed on laser transmissions by the U.S. Space Defense Operations Center (SPADOC) and a pointing error caused by the scan platform acceleration on the spacecraft being slower than expected (which prevented laser detection on all frames with less than 400 ms exposure times) all contributed to the reduction of the number of successful detections of the laser transmission to 48 of the total 159 frames taken. Nonetheless, the experiment was considered a resounding success and the data acquired will likely be used in the future to design laser "downlinks" which will send large volumes of data very quickly from spacecraft to Earth. The scheme was already being studied (as of 2004) for a data link to a future Mars orbiting spacecraft.
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Secondary payloads were: Ascent Particle Monitor (APM); Middeck 0-Gravity Dynamics Experiment (MODE); Shuttle Activation Monitor (SAM); Cosmic Ray Effects and Activation Monitor (CREAM); Physiological and Anatomical Rodent Experiment (PARE); Protein Crystal Growth II-2 (PCG II-2); Investigations into Polymer Membrane Processing (IPMP); and the Air Force Maui Optical Site (AMOS) experiment. The flight was the first to test an electronic still camera in space, a modified Nikon F4. Images obtained during the flight were monochrome with 8 bits of digital information per pixel (256 gray levels) and stored on a removable hard disk. The images could be viewed and enhanced on board using a modified lap- top computer before being transmitted to the ground via the orbiter digital downlinks.
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As an example, the capability downlinks on Spirit and Opportunity rovers had only the capability of the Mars Reconnaissance Orbiter downlink. Relay communication addresses this problem by allowing Mars surface spacecraft to communicate using higher data rates over short-range links to nearby Mars orbiters, while the orbiter takes on the task of communicating over the long-distance link back to Earth. This relay strategy offers a variety of key benefits to Mars landers: increased data return volume, reduced energy requirements, reduced communications system mass, increased communications opportunities, robust critical event communications and in situ navigation aid. NASA provided an Electra telecommunications relay and navigation instrument to assure communications between probes and rovers on the surface of Mars and controllers on Earth.
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Compared with C-band, Ku band is not similarly restricted in power to avoid interference with terrestrial microwave systems, and the power of its uplinks and downlinks can be increased. This higher power also translates into smaller receiving dishes and points out a generalization between a satellite's transmission and a dish's size. As the power increases, the size of an antenna's dish will decrease. This is because the purpose of the dish element of the antenna is to collect the incident waves over an area and focus them all onto the antenna's actual receiving element, mounted in front of the dish (and pointed back towards its face); if the waves are more intense, fewer of them need to be collected to achieve the same intensity at the receiving element.
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IAASARS/NOA ground segment has been expanded in the framework of the BEYOND project with the installation of an X-, and L-band satellite acquisition station for reception, acquisition, and processing of the direct broadcast downlinks from satellite missions including the EOS Aqua & Terra satellites (MODIS), the NPP (VIIRS, ATMS, etc.), the future NPOESS, the NOAA, the FYI, and the MetOP satellites. The IAASARS/NOA ground segment is equipped with the proper processing, archiving, and cataloging facilities for handling in real time image data from the missions above, as well as the future Copernicus satellite missions (Sentinels) through ESA's ground segment. Those ground segment facilities foster the development of a wide range of environmental monitoring services, such as: aerosol pollution indexes assessment, dust and volcanic ash alerts, smoke dispersion forecasts, wildfire detection and monitoring, geo-hazard activity monitoring and assessment (earthquakes/volcanoes/landslides), and urban heat Island mapping.I. Keramitsoglou et al.
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The Nexus 4000 series consists of only the model 4001: a blade-switch module for IBM BladeCenter that has all 10 Gbit Fibre Channel over Ethernet or FCoE interfaces. This blade-switch had 14 server-facing downlinks running on 1 Gbit/s or 10 Gbit/s and six uplinks using 10 Gbit/s SFP+ modules. For out-of-band management three ethernet-interfaces are available: one external 10/100/1000 bit/s copper interface, one internal management interface for the AMM or Advanced Management Module and one in-band interface using the VLAN interface option. And this blade-switch also has a serial console cable for direct access to the CLICisco brochure Nexus 4001 At a Glance, PDF, retrieved 28 May 2011 At present only switches for the IBM blade systems are available. When the Nexus 4000 series were announced in 2009 it was expected that there would be Nexus 4001 series for IBM and Dell (and not HP)Bladesmadesimple.
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