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Results for “Optical communication systems”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Laser Communication Demonstration System (LCDS) and future mobile satellite services

The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth orbit. For future global satellite communication systems using intersatellite links, laser communications technology can offer reduced mass and power requirements and higher channel bandwidths without regulatory constraints. As currently envisioned, LCDS will consist of one or two orbiting laser communications terminals capable of demonstrating high data rate (greater than 750Mbps) transmission in a dynamic space environment. Two study teams led by Motorola and Ball Aerospace are currently in the process of conducting a Phase A/B mission definition study of LCDS under contracts with JPL/NASA. The studies consist of future application survey, concept and requirements definition, and a point design of the laser communications flight demonstration. It is planned that a single demonstration system will be developed based on the study results. The Phase A/B study is expected to be completed by the coming June, and the current results of the study are presented in this paper.

Chien-Chung Chen↗
NASA NTRS1995

Laser Communication Demonstration System (LSCS) and Future Mobile Satellite Services

The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth Orbit. For future global satellite communication systems using intersatellite links (ISLs), laser communications technology can offer reduced mass , reduced power requirements, and increased channel bandwidths without regulatory restraint. This paper provides comparisons with radio systems and status of the program.

laser communications intersatellite links↗
NASA NTRS1996

Optical Communications for Extreme Deep Space Missions

A recent study of deep space telecommunications systems was performed in support of NASA's Mission to the Solar System planing activity. The results show that high bandwidth communications (greater than 1Mbps) are feasible at high-value planetary targets provided there are investments in the ground and spacecraft communication infrastructure.

Optical Communications laser communications deep s↗
NASA NTRS1991

Optoelectronics research for communication programs at the Goddard Space Flight Center

Current optoelectronics research and development of high-power, high-bandwidth laser transmitters, high-bandwidth, high-sensitivity optical receivers, pointing, acquisition and tracking components, and experimental and theoretical system modeling at the NASA Goddard Space Flight Center is reviewed. Program hardware and space flight milestones are presented. It is believed that these experiments will pave the way for intersatellite optical communications links for both the NASA Advanced Tracking and Data Relay Satellite System and commercial users in the 21st century.

Krainak, Michael A.↗
NASA NTRS1991

Reduced electrical bandwidth receivers for direct detection 4-ary PPM optical communication intersatellite links

This interim progress report consists of copies of three reports written for NASA's Flight System Development and Demonstration (FSDD) project on optical intersatellite links. The first report, 'Test results of the PlessCor avalanche photodiode (APD) preamplifier for use in the 50 Mbps quaternary pulse position modulator (QPPM) receiver,' was prepared for NASA Goddard Space Flight Center. The second, 'Performance of Q-ary PPM receiver under additive white Gaussian noise,' was prepared at the request of NASA Lewis Research Center for testing the electronic systems for the FSDD project. The third, 'Use of a Bessel lowpass filter as an approximate raised cosine filter,' was written for raised cosine filter implementation in the FSDD QPPM receiver.

Davidson, Frederic M.↗
NASA NTRS1985

Semiconductor Laser Phased Array

Oscillations synchronized and modulated individually for beam steering. Phased array of GaAs infrared lasers put out powerful electronically-steerable coherent beam. Fabricated as integrated circuit on GaAs chip, new device particularly suited to optical communications, optical data processing and optical detection and ranging systems.

Katz, J.↗
NASA NTRSDate not supplied

Coherent Architectures for Free-Space Optical Communications

Custom coherent architectures can provide many advantages for FSO communications systems through co-development of integrated photonics, ASIC-or FPGA-based DSP algorithms, and system design to mitigate atmospheric turbulence and reduce pointing requirements.

David J Geisler↗
NASA NTRS1986

Optical technologies for communication satellite applications; Proceedings of the Meeting, Los Angeles, CA, Jan. 21, 22, 1986

The present conference considers topics encompassing the fields of satellite communications technology, optical subsystems, transmitters and receivers, subsystems for pointing and tracking, onboard processing- and component-related technologies, fiber-optic distribution networks, and reliability-related considerations. Attention is given to lightwave technology in microwave systems, the status of CO2 laser technology and homodyne receiver concepts for communication satellite optical links, laser Doppler measurement techniques for spacecraft, fiber-optic gyros for space applications, integrated acoustooptic device modules for communication, signal processing and computing, radiation-hardened optoelectronic components, and radiation effects on fiber-optics.

Bhasin, Kul↗
NASA NTRS1990

A unique multi-access laser communications transceiver system

A 'many points in one point' multiaccess laser system has been examined, and results are reported which indicating the feasibility of optical communications multiaccess communications is feasible and that the resultant terminal size and with savings are very substantial compared to the dedicated optical terminals or RF multiaccess approaches. A preliminary design has been accomplished of a package that can weigh less than 150 pounds and which uses a 10-in. effective diameter fixed telescope and requires less than 100 W of regulated power and less than 8 cu ft of space.

Ross, Monte↗
NASA NTRS2016

Considerations for an Earth Relay Satellite with RF and Optical Trunklines

Support for user platforms through the use of optical links to geosynchronous relay spacecraft are expected to be part of the future space communications architecture. The European Data Relay Satellite System (EDRS) has its first node, EDRS-A, in orbit. The EDRS architecture includes space-to-space optical links with a Ka-Band feeder link or trunkline. NASA's Laser Communications Relay Demonstration (LCRD) mission, originally baselined to support a space-to-space optical link relayed with an optical trunkline, has added an Radio Frequency (RF) trunkline. The use of an RF trunkline avoids the outages suffered by an optical trunkline due to clouds, but an RF trunkline will be bandwidth limited. A space relay architecture with both RF and optical trunklines could relay critical realtime data, while also providing a high data volume capacity. This paper considers the relay user scenarios that could be supported, and the implications to the space relay system and operations. System trades such as the amount of onboard processing and storage required, the use of link layer switching vs. network layer routing, and the use of Delay/Disruption Tolerant Networking (DTN) are discussed.

Space Communications↗
NASA NTRS2016

Considerations for an Earth Relay Satellite with RF and Optical Trunklines

Support for user platforms through the use of optical links to geosynchronous relay spacecraft are expected to be part of the future space communications architecture. The European Data Relay Satellite System (EDRS) has its first node, EDRS-A, in orbit. The EDRS architecture includes space-to-space optical links with a Ka-Band feeder link or trunkline. NASA's Laser Communications Relay Demonstration (LCRD) mission, originally baselined to support a space-to-space optical link relayed with an optical trunkline, has added an Radio Frequency (RF) trunkline. The use of an RF trunkline avoids the outages suffered by an optical trunkline due to clouds, but an RF trunkline will be bandwidth limited. A space relay architecture with both RF and optical trunklines could relay critical realtime data, while also providing a high data volume capacity. This paper considers the relay user scenarios that could be supported, and the implications to the space relay system and operations. System trades such as the amount of onboard processing and storage required, the use of link layer switching vs. network layer routing, and the use of Delay/Disruption Tolerant Networking (DTN) are discussed.

Space Communications↗
NASA NTRS2011

A Study of an Optical Lunar Surface Communications Network with High Bandwidth Direct to Earth Link

Analyzed optical DTE (direct to earth) and lunar relay satellite link analyses, greater than 200 Mbps downlink to 1‐m Earth receiver and greater than 1 Mbps uplink achieved with mobile 5‐cm lunar transceiver, greater than 1Gbps downlink and greater than 10 Mpbs uplink achieved with 10‐cm stationary lunar transceiver, MITLL (MIT Lincoln Laboratory) 2013 LLCD (Lunar Laser Communications Demonstration) plans to demonstrate 622 Mbps downlink with 20 Mbps uplink between lunar orbiter and ground station; Identified top five technology challenges to deploying lunar optical network, Performed preliminary experiments on two of challenges: (i) lunar dust removal and (ii)DTN over optical carrier, Exploring opportunities to evaluate DTN (delay-tolerant networking) over optical link in a multi‐node network e.g. Desert RATS.

lunar surface system↗
NASA NTRS1995

Potential future applications for the tracking and data relay satellite II (TDRS II) system

During the conceptual design phases of the tracking and data relay satellite (TDRS) II system provision was made for a future service growth (FSG) payload with an undefined mission. The intent of the FSG was to provide a resource for TDRS II applications which would be available to meet a change in requirements for the operational TDRS II system. This paper summarizes the effect of the consideration of potential FSG applications imposed on the tracking and data relay satellite (TDRS) II system. The following applications were considered as FSG candidates: An optical 650 Mbps space-to-space link (SSL) coupled to an optical or RF downlink, an RF or optical crosslink to extend the baseline TDRS II system coverage, -zone of exclusion (ZOE) closure, relay for lunar communications either RF or optically, and relay for Martian communications either RF or optically. This paper summarizes work done in the 1990 time frame on the above stated applications. Since then, NASA has sponsored several studies (during phase B of the TDRS II development cycle) of the ZOE closure application of the FSG. The purpose of this paper is to report on the efforts previously considered for the FSG. A previous paper was presented at the 1991 Congress related to the second application above. This paper extends this effort to the four stated applications.

Gibbons, Richard C.↗
NASA NTRSDate not supplied

Current Status of NASA’s Low-Cost Optical Terminal (LCOT) at Goddard Space Flight Center

This paper provides the status of ongoing work at NASA-Goddard Space Flight Center (GSFC) to build a low-cost flexible ground terminal for optical communication. For laser communication to be cost-effective for future missions, a global network of flexible optical terminals must be put in place. There is a need for a single ground terminal design capable of supporting multiple missions ranging from LEO to lunar distances. NASA’s Low-Cost Optical Terminal (LCOT) has a single modular design that can be quickly reconfigured to support different laser communications missions. The LCOT prototype uses a 70cm commercially available telescope designed with optical and quantum communications in mind. This telescope is currently being integrated with a state-of-the-art adaptive optics system, and novel high-power laser amplifier demonstrate its utility as an optical communications receiver by receiving a downlink from the recently launched Laser Communication Relay Demonstration (LCRD). LCOT uses commercially available components wherever possible, and where commercial options are not available, the LCOT team works with vendors to create commercial options. This paper discusses the development progress for the blueprint of NASA’s future global ground terminal network.

Laser communications↗