TDRSS Demand Access System augmentation

Hogie, Keith; Criscuolo, Edward; Dissanayake, A.; Flanders, Bruce; Safavi, Haleh; Lubelczyk, Jeffry

doi:10.1109/aero.2015.7119263

Cited by 9 publications

(5 citation statements)

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“…The SCPPM encoder is composed of an outer convolutional encoder, a bit interleaver, and an accumulator-PPM (APPM) referred to as the "inner encoder." The convolutional encoder is described by the generator polynomials g (1) (D) = 1 + D 2 g (2) (D) = 1 + D + D 2 g (3) (D) = 1 + D + D 2 (30) along with the puncturing patterns specified in [32]. The three code rates require three different lengths for the input block u, as previously described, to generate a fixed-length output of 15 120 bit.…”

Section: Discussionmentioning

confidence: 99%

“…More than a decade later, in 1983, the first tracking and data relay satellite service ever became operational, with the aim of providing near-continuous communications and tracking services to Low Earth Orbit (LEO) spacecrafts, launch vehicles, and suborbital platforms in general. Although several alternatives to offer data relay services to satellites orbiting in Earth proximity have been envisaged, mainly from national agencies, but also from commercial companies (e.g., [2], [3]), to date, only two successful relay satellite systems exist: 1) The Tracking and Data Relay Satellite System (TDRSS) and (2) The European Data Relay Satellite System (EDRSS) [4].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two-Leg Deep-Space Relay Architectures: Performance, Challenges, and Perspectives

Modenini

Locarini

Valentini

et al. 2022

IEEE Trans. Aerosp. Electron. Syst.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Two-Leg Deep-Space Relay Architectures: Performance, Challenges, and Perspectives

Modenini

Locarini

Valentini

et al. 2022

IEEE Trans. Aerosp. Electron. Syst.

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“…The GEO data relay concept has been known for many years and has been successfully implemented by, eg, the NASA—Tracking and Data Relay Satellite System,() the JAXA—Data Relay Test Satellite, or the ESA—European Data Relay System. () Although these data relay systems can partially offer very high data rates, they can only serve a few LEO satellites concurrently.…”

Section: Introductionmentioning

confidence: 99%

An adaptive calibration and beamforming technique for a GEO satellite data relay

Winterstein

Greda

2017

Satell Commun Network

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High throughput data links from low Earth orbit satellites through a geostationary orbit satellite data relay have been proposed to increase the available contact times to ground stations. Accurate antenna beam pointing and tracking of moving targets are key requirements for the relay satellite. In this work, we propose an adaptive calibration and beamforming methodology on the basis of least mean squares, which is suitable for a geostationary orbit data relay. The target system consists of the combination of a high gain reflector fed by a digitally steerable patch antenna array. The proposed method is first presented by numerical cosimulation of the antenna and the calibration algorithm. The results are then validated in an outdoor experimental setup with all digital signal processing implemented in a field-programmable gate array. We demonstrate the tracking ability and pointing performance of the digitally enhanced reflector antenna with gain fluctuations smaller than 3 dB over a field of view of at least 2,5 • . The demonstrated performance shows that the digitally enhanced reflector antenna is a suitable candidate for long-distance space communications. KEYWORDSadaptive signal processing, beamforming, calibration, least mean squares methods, reflector antennas INTRODUCTIONDuring the last years, the number of low Earth orbit (LEO) satellites for Earth observation purposes has increased significantly, and this trend will most probably continue in the future. 1 Each new generation of these satellites has better instruments on board and therefore can collect increasing amounts of data. Low Earth orbit satellites for Earth observation fly at altitudes between 500 and 800 km with orbital periods of roughly 100 minutes. As the contact time of a LEO satellite to a single ground station is relatively short during 1 orbital period (approximately 5-10 minutes), there is an increasing bottleneck in downloading all gathered data to Earth. Urgent data may have to wait for the next contact to be downloaded.Raising the amount of transmittable data can be done by increasing either the transmission data rate or its length. A significant increase in data rate can only be achieved if bigger antennas and/or more transmit power are used. Because of severe mass and power constraints on the LEO satellites, this can only be done to a moderate extent. A significant increase in the downloading time can be achieved, if a network of ground stations is used instead of a single one. However, the necessary overhead to synchronize and reunite the distributed data snippets would be considerable.Moreover, it leads to tremendous building and operation costs, as the ground stations should preferably be located in the polar regions because of highest visibility.That is why another option is used more and more frequently to increase the amount of downloaded data-a data relay to the Earth using geostationary orbit (GEO) satellites. A GEO satellite is located at a height of roughly 36 000 km above the Earth and has the same rotational rate. Therefo...

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“…This functionality is implemented at the hardware level using FPGAs that ingest a stream of samples (∼ 6Gbps) and output ∼ 200Mbps for each of the 30 available independent beams [33]. Therefore, delays introduced by this functionality will be in the order of microseconds, thus allowing us to idealize the performance of this part of the system.…”

Section: Ri+1mentioning

confidence: 99%

Assessing the impact of real-time communication services on the space network ground segment

Net

Portillo

Cameron

et al. 2016

2016 IEEE Aerospace Conference

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Abstract-Communication networks to support space missions were originally architected around non-real time data services. In fact, missions have always required real-time services (e.g. telemetry and command), but the bulk of scientific data being returned to Earth has typically been highly delay tolerant. Nevertheless, future robotic and human exploration activities are rapidly pushing towards low latency, high data rate services. Examples can be found both in the near Earth domain (e.g. near real-imagery through NASAs LANCE program) and the deep space domain (e.g. HD video from Mars). Therefore, the goal of this paper is to quantify the effect of new real-time high data rate communication requirements on the ground segment of current communication networks.To that end, we start by analyzing operational schedules for NASAs Space Network (SN) in order to characterize the utilization of the overall network in terms of total data volume and contact time, as well as identify current mission drivers. These results are compared against proposed network requirements for future robotic and human near Earth exploration activities in order to quantitatively assess gaps in the SN capabilities. Using these results, we implement a rule-based expert system that translates SN-specific operational contacts into high-level data requirements for the ground segment of the network. We then exercise the expert system in order to derive the requirements that future exploration activities will impose on the SN. Finally quantify the impact of real-time data delivery services across NASAs ground segment by computing the wide-area network cost for different levels of data timeliness.

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TDRSS Demand Access System augmentation

Cited by 9 publications

References 0 publications

Two-Leg Deep-Space Relay Architectures: Performance, Challenges, and Perspectives

Two-Leg Deep-Space Relay Architectures: Performance, Challenges, and Perspectives

An adaptive calibration and beamforming technique for a GEO satellite data relay

Assessing the impact of real-time communication services on the space network ground segment

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