Search NASA⌕ Search

SEARCH · Search NASA

Results for “Communications and Navigation”

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.

At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Ionosphere/microwave beam interaction study

A solar power satellite microwave power density of 20mw sq cm was confirmed as the level where nonlinear interactions may occur in the ionosphere, particularly at 100 km altitude. Radio wave heating at this altitude, produced at the Arecibo Observatory, yielded negative results for radio wave heating of an underdense ionosphere. Overdense heating produced striations in the ionosphere which may cause severe radio frequency interference problems under certain conditions. The effects of thermal self-focusing are shown to be limited severely geographically. The aspect sensitivity of field-aligned striations makes interference-free regions above magnetic latitude about 60 deg. A test program is proposed to simulate the interaction of the SPS beam with the ionosphere, to measure the effects of the interaction on the ionosphere and on communication and navigation systems, and to interpret the results.

Duncan, L. M.↗
NASA NTRS1977

Space-borne power conversion into a microwave beam and its impact on the environment of the upper atmosphere

The possible effect of microwave beams transmitted from Solar Power Satellites on the ionosphere has been studied theoretically. Particular attention is given to microwave-beam-heating of the F and D layers and theoretical predictions of such ionospheric modifications are used to determine resulting effects on the transmission efficiency of communication and navigation systems. It is recommended that a three-pronged technology and demonstration program be established to study microwave effects. The program would include theoretical studies, ground-based heating experiments, and an orbital experimental program for phase control of the microwave power transmission system.

Maynard, O. E.↗
NASA NTRS1978

The year for shaping a digital operations R&D program

Digital systems which deal with functions outside the aircraft in commercial aviation are discussed with attention to navigation and communication. New systems of air traffic control (ATC) are described, including time division multiple access (TDMA) to ground-based ATC units and to the Navstar/GPS (global positioning system). Such innovations are expected to come on-line before the mid-1980s, and greatly increase air safety, while at the same time making a pilot's work easier.

Reid, H. J. E., Jr.↗
NASA NTRS1977

Satellite Power System (SPS) microwave subsystem impacts and benefits

The impacts and benefits to society of the microwave subsystem resulting from the developing, construction and operating of a space solar power to earth, electric power delivery system are presented and discussed. The primary benefit (usable energy) is conveyed mainly in the fundamental frequency portion of the RF radiation beam that is intercepted and converted to electric power output. The small fraction of the microwave and other electromagnetic energy that does not end up in the electric utility grid, yields most of the subsystem impacts. The impacts range from harmonics and noise radiated by the transmitting antenna, through potential interference with ionospheric communications and navigation caused by the power beam heating the ionosphere, to the potential large land area requirements for the rectennas and low level microwave radiation around the rectennas. Additional benefits range from a very low level of waste heat liberated and lack of atmospheric emissions including noise while operating to having no residual ionizing radiation from the rectenna when it is deactivated.

Dickinson, R. M.↗
NASA NTRS1979

The Deep Space Network

Deep Space Network progress in flight project support, tracking and data acquisition, research and technology, network engineering, hardware and software implementation, and operations is cited. Topics covered include: tracking and ground based navigation; spacecraft/ground communication; station control and operations technology; ground communications; and deep space stations.

Source record↗
NASA NTRS1979

Planning Space Shuttle's maiden voyage

NASA's first Space Shuttle, Columbia, whose technological advances include a space laboratory, navigational and communication satellites, and planetary explorers, is examined, and the first few flights, scheduled for 1980, are described. The Shuttle employs an all-digital, all-electronic, computer-operated avionics system. The onboard data processing and software subsystem, encompassing five computers (four online and one backup), a data-bus network, bus terminals, and software, is analyzed in detail. Attention is given to the basic structure of the Orbiter (37.19 m in length and 23.77 m wingspan), its main engines, and the payload and cargo capacities (29,500 kg). A two-step program that could increase the power and duration of spaceflights is presented. The first step is the creation of a power extension package, using solar arrays, generating electricity to extend the basic five-day flight to 20 days, while the second step uses the same design to create a 25-kW power model capable of providing energy for a 50-day flight. Plans for construction of a manned space construction base and a larger power platform of 250 kW are also presented.

Malkin, M. S.↗
NASA NTRS1971

Earth orbital experiment program and requirements study

A compilation of Earth orbital experiments and their required support technological developments is given. Six disciplines including manned spaceflight capability, space biology, spce astronomy, space physics, communications and navigation, and Earth observations were subjected to an overview analysis that resulted in the identifiying of 3,800 critical issues. Of these critical issues, 1,983 that were deemed suitable for near-term manned space research were grouped into 136 research clusters in accordance with commonality of instrumentation and measurements. These clusters are described at a level of detail that identifies the important aspects of the research and establishes the principal requirements that will be placed on the missions in accomplishing the research and on the space research facilities for these missions. Summaries of the space facility requirements and guidelines for mission planning are given. The supporting technology developments required to pursue the research are identified and grouped into 233 work packages.

Source record↗
NASA NTRS1980

Just over the horizon in space

The article surveys some of the concepts introduced and examined by a New Concepts Symposium convened by the NASA Advisory Council recently. Results are reported from the symposium's eight working groups: astrophysics, climate, communications and navigation, energy, large structures, planetary exploration, propulsion and transportation, and telefactors.

Bekey, I.↗
NASA NTRS1981

Nonducted coherent VLF waves and associated triggered emissions observed on the ISEE-1 satellite

A description is given of new observations of nonducted coherent VLF waves from ground-based transmitters and associated VLF emissions in the magnetosphere. The data reported were acquired by the Stanford University VLF Wave Injection Experiment on the ISEE-1 satellite. The experiment has four main components, including a broadband (1-32 kHz) VLF receiver on ISEE-1 connected to a long electric antenna, a broadband (1-20 kHz) controllable VLF transmitter located at Siple Station in the Antarctic, various VLF navigation and communications transmitters, and ground stations in the Antarctic and Canada. The main goal of the experiment is to acquire understanding of interactions between coherent VLF waves and energetic particles in the magnetosphere, in particular the whistler mode instability through which both natural and stimulated VLF emissions are produced.

Bell, T. F.↗
NASA NTRS1981

Report on Active and Planned Spacecraft and Experiments

Active and planned spacecraft activity and experiments between June 1, 1980 and May 31, 1981 known to the National Space Science Data Center are described. The information covers a wide range of disciplines: astronomy, Earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. Each spacecraft and experiment is described and its current status presented. Descriptions of navigational and communications satellites and of spacecraft that contain only continuous radio beacons used for ionospheric studies are specifically excluded.

Vostreys, R. W.↗
NASA NTRS1983

Application of the Hardman methodology to the Army Remotely Piloted Vehicle (RPV)

The application of the HARDMAN Methodology to the Remotely Piloted Vehicle (RPV) is described. The methodology was used to analyze the manpower, personnel, and training (MPT) requirements of the proposed RPV system design for a number of operating scenarios. The RPV system is defined as consisting of the equipment, personnel, and operational procedures needed to perform five basic artillery missions: reconnaissance, target acquisition, artillery adjustment, target designation and damage assessment. The RPV design evaluated includes an air vehicle (AV), a modular integrated communications and navigation system (MICNS), a ground control station (GCS), a launch subsystem (LS), a recovery subsystem (RS), and a number of ground support requirements. The HARDMAN Methodology is an integrated set of data base management techniques and analytic tools, designed to provide timely and fully documented assessments of the human resource requirements associated with an emerging system's design.

Source record↗
NASA NTRS1985

Research and technology: Fiscal year 1984 report

Topics covered include extraterrestrial physics, high energy astrophysics, astronomy, solar physics, atmospheres, oceans, terrestrial physics, space technology, sensors, techniques, user space data systems, space communications and navigation, and system and software engineering.

Source record↗
NASA NTRS1985

International space research perspectives of commercialization for German industry

A brief overview of space flight activities is presented. West German contributions to satellite mapping, communication satellites, navigation, Spacelab, diffusion under weightlessness, crystal growth in space, metal bonding, and biochemistry are described. The future of the research in the space station is analyzed.

Jordan, H. L.↗
NASA NTRS1984

A simulator application of a 'hands-on throttle and stick' concept to a transport pilot/autopilot interface

This paper presents the initial experiences garnered in applying a multifunction control strategy, based on the U.S. Air Force's 'Hands-On Throttle-and-Stick' concept for fighter aircraft to a transport aircraft simulator. The multifunction control strategy involves the activation of various flight system/subsystem operations (such as guidance and control, communication, and navigation functions) by use of menu displays and throttle and stick switches. The initial application of this multifunction control (MFC) concept was developed around a pilot/autopilot interface, contrasting a conventional, dedicated autopilot interface to an MFC implementation. The simulator characteristics and autopilot functions, as well as the conventional interface and MFC hardware/software, which were utilized in the application, are described herein. Initial pilot reaction and suggested improvements to this particular implementation are discussed. The paper terminates with a glance at plans for improvements and future applications based on the outcome of this initial study.

Busquets, A. M.↗
NASA NTRS1984

Pilot errors as a source of workload

A pilot opinion survey was conducted to develop a database for creating simulation scenarios that impose predetermined levels of pilot workload. Twelve pilots estimated the effect of 163 events and activities (which they had encountered during their previous flying experiences) on performance, effort, workload, and stress. The events, described in the context of flight scenario segments, included control, navigation and communications activities, aircraft and system failures, and pilot errors. In general, workload, stress, and effort ratings were significantly correlated with each other but not with performance ratings; however, some different response patterns were found as a function of flight segment (e.g., workload, stress, and performance, but not effort, ratings varied with flight phase) and type of event. Errors were rated as a significant source of change for workload, stress, and performance, suggesting that errors could be conceptualized as a cause of workload rather than as a symptom.

Hart, S. G.↗
NASA NTRS1986

Global Timing With Low- and High-Orbiting Satellites

Report summarizes method for synchronizing clocks at intercontinental distances employing satellites of Global Positioning System (GPS) in high Earth orbit and transit satellite in orbit at relatively low altitude of about 1,300 km. When fully implemented, method expected to supply precise time measurements for world-wide communication and navigation.

Wu, S. C.↗
NASA NTRS1985

Research and technology, fiscal year 1985

Capabilities in spacecraft subsystems, sensors, space communications and navigation, the acquisition of data from space missions and the extraction of information from that data were reviewed. The use of satellite data in the study of the Earth's atmosphere and climate, the dynamics of its crust and the monitoring of land and water resources were examined. A review of NASA flight projects for 1985 was presented.

Source record↗