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Results for “Consultative Committee for Space Data 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 109 records · Page 6
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NASA NTRS1991

An algorithm to design a multiple-channel communications system

The authors present a novel algorithm to design a phase-modulated residual carrier communications system for optimum performance. The algorithm has been developed as an aid in the design of two telemetry data channels operating simultaneously with a turn-around ranging signal. The algorithm provides the selection of an optimum subcarrier frequency and modulation indices for minimizing the mutual interferences among the channels to achieve desired link performance margins. The set of modulation indices provided by this algorithm will also achieve an optimum power division between the carrier, the ranging and the high data rate and low data rate channels. Finally, a software program using this algorithm has been developed for use with personal computers. This program provides the computation of the optimum subcarrier frequencies and modulation indices for a standard case that is recommended by the international Consultative Committee for Space Data Systems.

Nguyen, Tien M.↗
NASA NTRS2004

Downlink Data Multiplexer

A multiplexer/demultiplexer system has been developed to enable the transmission, over a single channel, of four data streams generated by a variety of sources at different (including variable) bit rates. In the original intended application, replicas of this multiplexer/demultiplexer system would be incorporated into the spacecraft-to-ground communication systems of the space shuttles. The multiplexer of each system would be installed in the spacecraft, where it would acquire and process data from such sources as commercial digital camcorders, video tape recorders, and the spacecraft telemetry system. The demultiplexer of each system would be installed in a ground station. Purely terrestrial systems of similar design could be attractive for use in situations in which there are requirements to transmit multiple streams of high-quality video data and possibly other data over single channels. The figure is a block diagram of the multiplexer as configured to process data received via three fiber-optic channels like those of the International Space Station and one electrical-cable channel that conforms to the Institute of Electrical and Electronic Engineers (IEEE) 1394 standard. (This standard consists of specifications of a high-speed serial data interface, the physical layer of which includes a cable known in the art as "FireWire." An IEEE 1394 interface can also transfer power between the components to which it is connected.) The fiber-optic channels carry packet and/or bit-stream signals that conform to the standards of the Consultative Committee for Space Data Systems (CCSDS). The IEEE 1394 interface accepts an isochronous signal like that from a digital camcorder or a video tape recorder. The processing of the four input data streams to combine them into one output stream is governed by a statistical multiplexing algorithm that features a flow-control capability and makes it possible to utilize the transmission channel with nearly 100-percent efficiency. This algorithm allocates the available bandwidth of the transmission channel to the data streams according to a combination of data rates and preassigned priorities. Incoming data streams that demand too much bandwidth are blocked. Bandwidth not needed for a transmission of a given data stream is allocated to other streams as available. Priority is given to the IEEE 1394 stream. In addition to the four incoming data streams, the multiplexer transmits data on the status of the system. An operator can monitor and control the multiplexer via displays and controls on the multiplexer housing. The output of the multiplexer is connected via a coaxial cable with an impedance of 50 Ohms to an interface circuit compatible with the space-shuttle high-speed digital downlink, which operates at a rate of 48 Mb/s.

Holland, Douglas↗
NASA NTRS2016

Future Standardization of Space Telecommunications Radio System with Core Flight System

NASA Glenn Research Center (GRC) is integrating the NASA Space Telecommunications Radio System (STRS) Standard with the Core Flight System (cFS). The STRS standard provides a common, consistent framework to develop, qualify, operate and maintain complex, reconfigurable and reprogrammable radio systems. The cFS is a flexible, open architecture that features a plug-and-play software executive called the Core Flight Executive (cFE), a reusable library of software components for flight and space missions and an integrated tool suite. Together, STRS and cFS create a development environment that allows for STRS compliant applications to reference the STRS APIs through the cFS infrastructure. These APis are used to standardize the communication protocols on NASAs space SDRs. The cFE-STRS Operating Environment (OE) is a portable cFS library, which adds the ability to run STRS applications on existing cFS platforms. The purpose of this paper is to discuss the cFE-STRS OE prototype, preliminary experimental results performed using the Advanced Space Radio Platform (ASRP), the GRC Sband Ground Station and the SCaN (Space Communication and Navigation) Testbed currently flying onboard the International Space Station. Additionally, this paper presents a demonstration of the Consultative Committee for Space Data Systems (CCSDS) Spacecraft Onboard Interface Services (SOIS) using electronic data sheets inside cFE. This configuration allows for the data sheets to specify binary formats for data exchange between STRS applications. The integration of STRS with cFS leverages mission-proven platform functions and mitigates barriers to integration with future missions. This reduces flight software development time and the costs of software-defined radio (SDR) platforms. Furthermore, the combined benefits of STRS standardization with the flexibility of cFS provide an effective, reliable and modular framework to minimize software development efforts for spaceflight missions.

space communications↗
NASA NTRS2016

Future Standardization of Space Telecommunications Radio System with Core Flight System

NASA Glenn Research Center (GRC) is integrating the NASA Space Telecommunications Radio System (STRS) Standard with the Core Flight System (cFS), an avionics software operating environment. The STRS standard provides a common, consistent framework to develop, qualify, operate and maintain complex, reconfigurable and reprogrammable radio systems. The cFS is a flexible, open architecture that features a plugand- play software executive called the Core Flight Executive (cFE), a reusable library of software components for flight and space missions and an integrated tool suite. Together, STRS and cFS create a development environment that allows for STRS compliant applications to reference the STRS application programmer interfaces (APIs) that use the cFS infrastructure. These APIs are used to standardize the communication protocols on NASAs space SDRs. The cFS-STRS Operating Environment (OE) is a portable cFS library, which adds the ability to run STRS applications on existing cFS platforms. The purpose of this paper is to discuss the cFS-STRS OE prototype, preliminary experimental results performed using the Advanced Space Radio Platform (ASRP), the GRC S‑ band Ground Station and the SCaN (Space Communication and Navigation) Testbed currently flying onboard the International Space Station (ISS). Additionally, this paper presents a demonstration of the Consultative Committee for Space Data Systems (CCSDS) Spacecraft Onboard Interface Services (SOIS) using electronic data sheets (EDS) inside cFE. This configuration allows for the data sheets to specify binary formats for data exchange between STRS applications. The integration of STRS with cFS leverages mission-proven platform functions and mitigates barriers to integration with future missions. This reduces flight software development time and the costs of software-defined radio (SDR) platforms. Furthermore, the combined benefits of STRS standardization with the flexibility of cFS provide an effective, reliable and modular framework to minimize software development efforts for spaceflight missions.

space communications↗
NASA NTRS1983

Packet telemetry and packet telecommand - The new generation of spacecraft data handling techniques

Because of rising costs and reduced reliability of spacecraft and ground network hardware and software customization, standardization Packet Telemetry and Packet Telecommand concepts are emerging as viable alternatives. Autonomous packets of data, within each concept, which are created within ground and space application processes through the use of formatting techniques, are switched end-to-end through the space data network to their destination application processes through the use of standard transfer protocols. This process may result in facilitating a high degree of automation and interoperability because of completely mission-independent-designed intermediate data networks. The adoption of an international guideline for future space telemetry formatting of the Packet Telemetry concept, and the advancement of the NASA-ESA Working Group's Packet Telecommand concept to a level of maturity parallel to the of Packet Telemetry are the goals of the Consultative Committee for Space Data Systems. Both the Packet Telemetry and Packet Telecommand concepts are reviewed.

Hooke, A. J.↗
NASA NTRS1983

Standard format data units - Tools for automatic exchange of space mission data

A set of standard formatting rules for the data sets, and a standard computer-readable language with which to describe the data, are two tools which are used to create the Standard Format Data Unit (SFDU). The NASA/JPL proposal for creation and utilization of SFDUs is presented, and its relationship to recommendations from the Consultative Committee for Space Data Systems (CCSDS) is discussed. Several current and planned implementations of the SFDU concept among major space flight projects are identified. The purpose of creating the concept of an SFDU is to allow members of the science community to share national and global resource data independently of project or program. The feedback from SFDU implementation efforts is considered an essential part of the CCSDS activity. Even though the CCSDS specifically deals with space data systems, the SFDU concept can be applied to practically every data system on an open network. The SFDU is in the early phase of CCSDS standard definition work, and must go through several other phases before being formally recommended as an international standard.

Willett, J. B.↗
NASA NTRS1985

Reed-solomon Code Synchronization Revisited

A concatenated coding consisting of an inner (7, 1/2) convolutional code and an outer (255, 223) Reed-Solomon code was recommended by the Consultative Committee for Space Data Systems for cross-supported space missions. The Reed-Solomon code that was chosen makes use of the Berlekamp encoding algorithm. Some peculiarities of this code that could give rise to synchronization problems are examined. Suggestions are given to alleviate these problems.

Deutsch, L. J.↗
NASA NTRS1985

A VLSI single chip (255,223) Reed-Solomon encoder

A description of a working single chip implementation of a Reed-Solomon encoder. The code used is the Consultative Committee on Space Data Systems (CCSDS) standard (255,223) code. The architecture that leads to this single very large scale integration chip design makes use of a bit-serial finite field multiplication algorithm of E. R. Berlekamp.

Deutsch, L. J.↗
NASA NTRS1989

A new VLSI architecture for a single-chip-type Reed-Solomon decoder

A new very large scale integration (VLSI) architecture for implementing Reed-Solomon (RS) decoders that can correct both errors and erasures is described. This new architecture implements a Reed-Solomon decoder by using replication of a single VLSI chip. It is anticipated that this single chip type RS decoder approach will save substantial development and production costs. It is estimated that reduction in cost by a factor of four is possible with this new architecture. Furthermore, this Reed-Solomon decoder is programmable between 8 bit and 10 bit symbol sizes. Therefore, both an 8 bit Consultative Committee for Space Data Systems (CCSDS) RS decoder and a 10 bit decoder are obtained at the same time, and when concatenated with a (15,1/6) Viterbi decoder, provide an additional 2.1-dB coding gain.

Hsu, I. S.↗
NASA NTRS1989

Performance analysis of CCSDS path service

A communications service, called Path Service, is currently being developed by the Consultative Committee for Space Data Systems (CCSDS) to provide a mechanism for the efficient transmission of telemetry data from space to ground for complex space missions of the future. This is an important service, due to the large volumes of telemetry data that will be generated during these missions. A preliminary analysis of performance of Path Service is presented with respect to protocol-processing requirements and channel utilization.

Johnson, Marjory J.↗
NASA NTRS1989

The next 40 years in space standards

Methods used in producing, introducing, and using standards for civilian space research are examined, with special consideration given to the recommendations of the Consultative Committee for Space Data Systems (CCSDS) as an example of a set of standards best coordinated through the International Standard Organization (ISO). The paper uses an example of earth-observation data as a CCSDS application for an international coordination effort within the ISO and describes progress in achieving this objective. Lists of CCDSD member agencies and CCSDS observer agencies are included.

Sheetz, H. J.↗
NASA NTRS1989

Data standards for the Space Station Freedom Program

The Space Station Freedom Program (SSFP) plans to utilize several of the Recommendations of the Consultative Committee for Space Data Systems (CCSDS). This paper discusses four aspects of the effect of the Advanced Orbiting Systems (AOS) within the SSFP which are of special interest. It is first noted that the AOS is a new Recommendation of the CCSDS, and the SSFP has been in the unique position of playing a major role in the development of the Recommendation. Interactions of the process by the Program and the CCSDS are shown. Second, the specific application of the CCSDS AOS Recommendation to each of the four SSFP flight elements and the resulting sets of services provided on each element are discussed. Third, the usefulness and importance of the AOS Recommendation within the context of the international nature of the SSFP and as part of the generation of interorganizational support agreements within NASA are discussed. Finally, the current status of baselining various CCSDS Recommendations, especially the AOS, into the SSFP requirements structure is given.

Carper, Richard D.↗
NASA NTRS1990

Telemetry and command standards

The first phase of the international Consultative Committee for Space Data Systems (CCSDS) efforts toward the definition of standards for space telemetry, spacecraft tracking, and command functions has established a set of standard space communications techniques capable of satisfying almost the entire spectrum of space mission user requirements. This was achieved by focusing on the distinctive problems associated with the space/ground data link, and developing the infrastructural system designated the 'Open Systems Interconnection'. The intrinsically international coordination by CCSDS of development efforts ensures highly flexible mutual support activities by the various national space agencies.

Hooke, Adrian J.↗
NASA NTRS1990

Application of CCSDS packet telemetry recommendations by JPL

The Consultative Committee for Space Data Systems (CCSDS) has adopted three Recommendations dealing with telemetry for conventional missions: Packet Telemetry, Telemetry Channel Coding and Time Code Formats. The currently flying JPL spacecraft were designed prior to the adoption of these Recommendations. Future JPL missions will be compatible, as will the Deep Space Network and Space Flight Operations Center. This paper discusses ways in which application of the Recommendations causes or allows functions to be done differently from previous JPL projects, including the impact on timing and on telemetry adaptability.

Moyd, K. I.↗
NASA NTRS1991

Standard formatted data units-control authority procedures

The purpose of this document is to establish a set of minimum and optional requirements for the implementation of Control Authority (CA) organizations within and among the Agencies participating in the Consultative Committee for Space Data Systems (CCSDS). By satisfying these requirements, the resultant cooperating set of CA organizations will produce a global CA service supporting information transfer with digital data under the Standard Formatted Data Unit (SFDU) concept. This service is primarily accomplished through the registration, permanent archiving, and dissemination of metadata in the form of Metadata Objects (MDO) that assist in the interpretation of data objects received in SFDU form. This Recommendation addresses the responsibilities, services, and interface protocols for a hierarchy of CA organizations. The top level, consisting of the CCSDS Secretariat and its operational agent, is unique and primarily provides a global coordination function. The lower levels are Agency CA organizations that have primary responsibility for the registration, archiving, and dissemination of MDOs. As experience is gained and technology evolves, the CA Procedures will be extended to include enhanced services and their supporting protocols. In particular, it is anticipated that eventually CA organizations will be linked via networks on a global basis, and will provide requestors with online automated access to CA services. While this Recommendation does not preclude such operations, it also does not recommend the specific protocols to be used to ensure global compatibility of these services. These recommendations will be generated as experience is gained.

Source record↗
NASA NTRS1992

CCSDS - A forum to facilitate international cooperation among space agencies

An overview is presented of the Consultative Committee for Space Data Systems (CCSDS) in its role as a promoter the development and utilization of compatible data-systems standards among the principal space agencies of the world. Attention is also given to the CCSDS affiliation categories comprising member agencies, observer agencies, and associates. Consideration is given to the CCSDS organization, the technical panels, and current CCSDS recommendations.

Greene, Edward P.↗
NASA NTRS1993

Bandwidth characteristics of multimedia data traffic on a local area network

Limited spacecraft communication links call for users to investigate the potential use of video compression and multimedia technologies to optimize bandwidth allocations. The objective was to determine the transmission characteristics of multimedia data - motion video, text or bitmap graphics, and files transmitted independently and simultaneously over an ethernet local area network. Commercial desktop video teleconferencing hardware and software and Intel's proprietary Digital Video Interactive (DVI) video compression algorithm were used, and typical task scenarios were selected. The transmission time, packet size, number of packets, and network utilization of the data were recorded. Each data type - compressed motion video, text and/or bitmapped graphics, and a compressed image file - was first transmitted independently and its characteristics recorded. The results showed that an average bandwidth of 7.4 kilobits per second (kbps) was used to transmit graphics; an average bandwidth of 86.8 kbps was used to transmit an 18.9-kilobyte (kB) image file; a bandwidth of 728.9 kbps was used to transmit compressed motion video at 15 frames per second (fps); and a bandwidth of 75.9 kbps was used to transmit compressed motion video at 1.5 fps. Average packet sizes were 933 bytes for graphics, 498.5 bytes for the image file, 345.8 bytes for motion video at 15 fps, and 341.9 bytes for motion video at 1.5 fps. Simultaneous transmission of multimedia data types was also characterized. The multimedia packets used transmission bandwidths of 341.4 kbps and 105.8kbps. Bandwidth utilization varied according to the frame rate (frames per second) setting for the transmission of motion video. Packet size did not vary significantly between the data types. When these characteristics are applied to Space Station Freedom (SSF), the packet sizes fall within the maximum specified by the Consultative Committee for Space Data Systems (CCSDS). The uplink of imagery to SSF may be performed at minimal frame rates and/or within seconds of delay, depending on the user's allocated bandwidth. Further research to identify the acceptable delay interval and its impact on human performance is required. Additional studies in network performance using various video compression algorithms and integrated multimedia techniques are needed to determine the optimal design approach for utilizing SSF's data communications system.

Chuang, Shery L.↗
NASA NTRS1993

Error coding simulations

There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

Noble, Viveca K.↗