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Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented.
The baseline Tracking and Data Relay Satellite telecommunication system is described. The configurations of the user spacecraft terminal and the ground based terminal are illustrated. The system service and performance summary is developed to show the link support, modes of operation, and link performance to the low data rate and medium data rate user spacecraft. The link budget calculation is included to show a typical computation for each space-to-space and space-to-ground link with the assumptions used in each calculation.
A study of the use of newly emerging communications technology for improving the understanding between members of Congress and their constituents was conducted. The study employed a number of specific methodologies such as interdisciplinary systems model building, technology analysis, a sample survey, and semi-structured interviews using sketches of the emergent channels. The following configurations were identified as representative of emergent channel characteristics: (1) the teleconference, (2) the videoconference, (3) the videophone, (4) cable television, (5) cable television polling, and (6) information retrieval. Analysis of the interview data resulted in an overview of the current congressional-constituent communication system and an assessment of the potential for emergent telecommunications, as perceived by congressmen and senior staff from 40 offices in the stratified judgement sample.
Telecommunication network concepts are discussed together with carrier-tracking loops employing the phase-lock principle, phase and Doppler measurements in two-way phase-coherent tracking systems, range measurements by phase-coherent techniques, and questions of phase-coherent detection with perfect reference signals and with noisy reference signals. The design of one-way and two-way phase-coherent communication systems is considered, giving attention to the optimal design of single-channel systems, the design of two-channel systems, and the design of multichannel systems. Other topics explored include the design and the performance of phase-coherent systems preceded by band-pass limiters, symbol synchronization and its effects on data detection, noncoherent communication over the Gaussian channel, and tracking loops with improved performance.
A parametric analysis of the telecommunications support capability of the Tracking and Data Relay Satellite System (TDRSS) was performed. Emphasis was placed on maximizing support capability provided to the user while minimizing impact on the user spacecraft. This study evaluates the present TDRSS configuration as presented in the TDRSS Definition Phase Study Report, December 1973 to determine potential changes for improving the overall performance. In addition, it provides specifications of the user transponder equipment to be used in the TDRSS.
The technical characteristics of various telecommunications media are examined for incorporation into educational networks. FM radio, AM radio, and VHF and UHF television are considered along with computer-aided instruction. The application of iteration networks to library systems, and microform technology are discussed. The basic principles of the communications theory are outlined, and the operation of the PLATO 4 random access system is described.
The results of the telecommunications subsystem analysis are presented. The relay system requirements and constraints, interference analysis, frequency selection, modulation and coding analysis, and the performance analysis of the relay system are included.
Alternative approaches are analyzed to a National Law Enforcement Telecommunications Network (NALECOM) designed to service all state-to-state and state-to-national criminal justice communications traffic needs in the United States. Network topology options were analyzed, and equipment and personnel requirements for each option were defined in accordance with NALECOM functional specifications and design guidelines. Evaluation criteria were developed and applied to each of the options leading to specific conclusions. Detailed treatments of methods for determining traffic requirements, communication line costs, switcher configurations and costs, microwave costs, satellite system configurations and costs, facilities, operations and engineering costs, network delay analysis and network availability analysis are presented. It is concluded that a single regional switcher configuration is the optimum choice based on cost and technical factors. A two-region configuration is competitive. Multiple-region configurations are less competitive due to increasing costs without attending benefits.
In support of the ongoing NASA-European Space Agency (ESA) effort to understand and control possible interference between missions, testing was conducted at the Madrid Deep Space Station from July 1975 to February 1976 to characterize the effect on Viking 1975 telecommunication link performance of Geodetic Earth-Orbiting Satellite (GEOS) downlink signals. The prime use of the data was to develop a capability to predict GEOS interference effects for evaluation of Viking 1975 mission impacts and possible temporary GEOS shutdown. Also, the data would serve as a basis for assessment of the GEOS impact on missions other than Viking as well as for more general interference applications. Performances of the reference receiver, telemetry, and planetary ranging were measured in the presence of various types of GEOS-related interference, including an unmodulated GEOS carrier and simulation of the actual spectrum by an ESA-supplied GEOS suitcase model.
The Health/Education Telecommunications Experiment carried out with Applications Technology Satellite-6 is described. The experiment tested the effectiveness of color television broadcasts to over 120 low-cost receivers in rural areas. Five types of earth stations were involved: receive-only terminals (ROT), an intensive terminal consisting of the ROT plus a VHF transmitter and receiver; comprehensive S and C-band terminals having the capability of transmitting the video signal plus four audio channels; and the main originating stations. Additional supporting elements comprise 120 video receive terminals, 51 telephony transceivers, and 8 video originating terminals of 3 different parts. Technical parameters were measured to within 1 dB of the calculated values.
The TDRSS and tracking services define the telecommunication performance of the TDRSS between the RF interface with user spacecraft and the data interface with NASCOM at the ground terminal. Attention is given to system constraints, forward link services, multiple-access signal design parameters, S-band single access signal design parameters, multiple-access return link services, and single-access return link services.
The DSN-Mariner Jupiter/Saturn 1977 telecommunications compatibility tests conducted during the periods 15-20 November 1976, 7-16 December 1976 and 5 January 1977, are an ongoing series of engineering level tests to determine the flight-ground interface compatibility and performance characteristics between these two systems.
Deep Space Network-Voyager telecommunications compatibility tests are described. A series of engineering level tests to determine the flight-ground interface compatibility and performance characteristics between the two systems were utilized. A summary and status of tests conducted on Voyager spacecraft are reported.
Analysis discusses STACOM (state criminal justic communication) network topology program used to design and evaluate digital telecommunications networks STACOM employs ESAU-WILLIAMS technique to search for direct links between system terminations and regional switching center. Inputs include traffic data, terminal locations, and functional requirements.
A user's guide to the network design program is presented. The program is written in FORTRAN V and implemented on a UNIVAC 1108 computer under the EXEC-8 operating system which enables the user to construct least-cost network topologies for criminal justice digital telecommunications networks. A complete description of program features, inputs, processing logic, and outputs is presented, and a sample run and a program listing are included.
A brief description is given of United States participation in the process of developing the technical basis for international allocation and regulation of the radio frequency spectrum. The telecommunication requirements for deep space research are considered. Topics include functional requirements, methods and techniques, and equipment characteristics.
The Pioneer Venus 1978 flight project Deep Space Network telecommunications compatibility test program is discussed. Subsystem design tests performed during April 1977 and November 1977 are described.
NASA is currently conducting a series of millimeter wave satellite system market studies to develop 30/20 GHz satellite system concepts that have commercial potential. Four contractual efforts were undertaken: two parallel and independent system studies and two parallel and independent market studies. The marketing efforts are focused on forecasting the total domestic demand for long haul telecommunications services for the 1980-2000 period. Work completed to date and reported in this paper include projections of: geographical distribution of traffic; traffic volume as a function of urban area size; and user identification and forecasted demand.