SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Orbiting Data Relay Network communications system provides continuous wideband communication between ground and earth orbiting spacecraft via synchronous satellite repeaters
Position location and communication equipment for two-way voice and signal data communication between aircraft and ground control facilities, using geosynchronous satellite transponders
Quantum communication systems performance evaluated by communication efficiency parameter
Orbiting Data Relay Network communications system provides continuous wideband communication between ground and earth orbiting spacecraft via synchronous satellite repeaters
Communication in large organizations, describing internal communication model
Axioms of quantum measurements incorporated into communication estimation theory for optical communication
Multiple access communication satellite systems providing reliable speech communication for low density use in remote areas
This report presents the results of an evaluation of the communications system performance during the Apollo 7 mission. The report includes, in addition to a communications system performance evaluation presented previously (Reference 1 of Appendix A), a supplemental evaluation of additional data.
Pocket sized transmitter, frequency modulated by crystal derived tones, with integral loop antenna provides police with easy operating alert signal communicator which uses patrol car radio to relay signal. Communication channels are time shared by several patrol units.
High altitude aircraft test for visible laser communication and analysis of errors in optical communications experiment due to flight path inaccuracies
GCF area communications terminal subsystem high-speed data regeneration assembly for routing and conditioning all communications entering and leaving
Integration of space shuttle communication and navigation functions into Unified S-Band Communication and Navigation System
Atmospheric turbulence effects reduction in optical communication by statistical communication theory, considering digital system and waveform estimation
Lunar far side communication, discussing libration point and lunar orbit relay system for high bit rate telemetry, TV and astronaut backpack communication
Communication theory problems incorporating quantum effects for optical-frequency applications are discussed. Under suitable conditions, a unique quantum channel model corresponding to a given classical space-time varying linear random channel is established. A procedure is described by which a proper density-operator representation applicable to any receiver configuration can be constructed directly from the channel output field. Some examples illustrating the application of our methods to the development of optical quantum channel representations are given. Optimizations of communication system performance under different criteria are considered. In particular, certain necessary and sufficient conditions on the optimal detector in M-ary quantum signal detection are derived. Some examples are presented. Parameter estimation and channel capacity are discussed briefly.
The radio frequency communications subsystem for a space station is considered, with respect to onboard checkout requirements. The subsystem comprises all equipment necessary for transmitting and receiving, tracking and ranging, command, multiple voice and television information, and broadband experiment data. The communications subsystem provides a radio frequency interface between the space station and ground stations, either directly or indirectly, through a data relay satellite system, independent free-flying experiment modules, and logistics vehicles. Reliability, maintenance, and failure analyses are discussed, and computer programming techniques are presented.
The research concerned with the liaison, interface, coupling, and technology transfer processes that occur in research and development is reported. Overviews of the functions of communication and coupling in the R and D processes, and the theoretical considerations of coupling, communication, and values are presented along with descriptions of the field research program and the instrumentation.
The primary performance requirement of the spaceborne Apollo voice communications system is percent word intelligibility, which is related to other link/channel parameters. The effect of percent word intelligibility on voice channel design and a description of the verification procedures are included. Development and testing performance problems and the techniques used to solve the problems are also discussed. Voice communications performance requirements should be comprehensive and verified easily; the total system must be considered in component design, and the necessity of voice processing and the associated effect on noise, distortion, and cross talk should be examined carefully.