• International Telemetering Conference Proceedings, Volume 25 (1989)

      International Foundation for Telemetering, 1989-11
    • Systems Engineering and Integration of Control Centers in Support of Multiple Programs

      Miller, David N.; National Aeronautics and Space Administration (International Foundation for Telemetering, 1989-11)
      The Multiprogram Control Center (MPCC) at the Johnson Space Center (JSC) was envisioned as a means of satisfying the ground control requirements for complex Space Transportation System (STS) payloads and unmanned vehicles. This paper will describe the role and characteristics of the MPCC and its relationship to the STS Mission Control Center (MCC). It will also reveal significant problems encountered and useful solutions to some fairly generic problems. It will discuss the current direction of control center technology and vendor opportunities from the MPCC's perspective. It will conclude with specific lessons learned thus far in the MPCC project.
    • A Practical Methodology for Archiving, Retrieving, and Managing Large Quantities of Data

      Reinwald, Carl; Vossler, Bob; Computer Sciences Corporation (International Foundation for Telemetering, 1989-11)
      With the ever-increasing volume of data generated by today's telemetry processing systems, contemporary data archive technologies are proving inadequate for permanent data storage requirements. Typically after data have been acquired and recorded, specialized engineers will analyze and compare the current data with data archived during past operations. As the quantity of archived data increases, the data's accessibility becomes increasingly difficult to manage efficiently. A new archiving concept has been designed and implemented which provides efficient automated access to over three terabytes of data. The nominal retrieval time for a fifty megabyte file is less than two minutes. The system's storage media is standard VHS high-energy cassettes with a storage capacity of 5.2 gigabytes per cassette.
    • Modular PCM System with Wireless Interconnect

      Troth, William B.; Microcom Corporation (International Foundation for Telemetering, 1989-11)
      Versatility is the keyword in modern airborne telemetry systems. Only a system with an inherent ability to be changed can be cost effective in an environment where requirements change as often and as rapidly as in todays missile and aircraft test instrumentation. This paper will describe a totally wireless, modular, PCM telemetry system. Using stored program format control (user programmable) and implemented with low power programmable logic devices, this new system can be altered with minimal effort and cost. Functional modules can be added or changed as program requirements evolve. Elastomeric connectors are used to achieve high density, wireless, high reliability interconnection between modules. This connection technique allows easy access to individual modules for repair or replacement without damaging substrates or components.
    • Simulations of Space Station Data Links and Ground Processing

      Horan, Stephen; New Mexico State University (International Foundation for Telemetering, 1989-11)
      The telemetry group has begun a new program in conjunction with Goddard Space Flight Center to investigate the possibilities of using parallel processing configurations for the real-time processing of Space Station data. In order to evaluate the potential configurations, a program based on using discrete-event simulation models is being used. This modeling software allows for generic configurations to be modeled and the relevant parameters to be modified to see the effects on performance. This paper represents a description of the work we will be undertaking over the next 18 months and the environment to be used in creating the simulation models at NMSU.
    • Advanced Orbiting Systems: A Standard Architecture for Space Data Communications

      Hooke, Adrian J.; California Institute of Technology (International Foundation for Telemetering, 1989-11)
      The first thirty years of civilian space exploration were characterized by a series of individual missions, focussed towards specific goals and servicing small and close-knit user communities. Spacecraft (constrained by power, weight and volume considerations) were customized towards mission objectives. Their data handling and communications systems were primarily built for simplicity and robustness, and displayed little commonality from mission to mission. All of the easy space missions have now been flown. As we move into the 1990s, requirements exist for complex missions involving Earth observation, exploration and a more permanent human presence in space. Internationalization of these missions is inevitable as a means to distribute and share costs, and to increase their political stability. Automation of their data handling systems is essential to support reliable, low cost operations. Responding to this environment, the Consultative Committee for Space Data Systems (CCSDS) was formed in 1982 to develop and promote a full suite of internationally standardized space data communications protocols. The first set of recommended standards, covering the data handling requirements of conventional free-flying scientific spacecraft, was finalized in 1986. Using the international space station "Freedom" program (a cooperative venture between the US, Europe, Canada and Japan) as a requirements model, the CCSDS has now extended its suite of recommended standards to cover "advanced orbiting systems" such as unmanned and man-tended Earth observation platforms, new space transportation systems, and manned laboratories. These systems, which operate as longterm orbiting facilities and therefore have changing user communities, produce prodigious rates and volumes of data including digitized video and audio. For the first time, the orbiting systems will use local area networks for internal data transfer. On the ground, they will interface with networks designed for worldwide Open Systems Interconnection (OSI). This paper reviews the standard data handling service architecture which has been developed by CCSDS. It describes the communications protocols that are recommended for the networked transfer of space mission data, and focuses on the unique requirements of transmitting many different data types through weak signal, noisy space channels at rates which routinely may reach many hundreds of megabits per second.
    • Third-generation Advances in Thermal Printhead-based Chart Recorders

      Gaskill, Dave; Astro-Med, Inc. (International Foundation for Telemetering, 1989-11)
      A brief recap of the effect thermal printhead technology has had on the common 8-channel strip chart recorder, followed by a summary of second and third generation products and their envolving capabilities. How these new instruments are being accepted and used by telemetrists and ground station managers who are faced with bigger tasks and shrinking budgets. A study of how today's telemetry professionals are shaping the 8-channel recorders of tomorrow, and the new capabilities they will bring.
    • Data Rate Reduction Using a Digital Anti-Aliasing Filter

      Lee, Kyong H.; Maschhoff, Robert H.; Gulton Data Systems (International Foundation for Telemetering, 1989-11)
      In this paper we explore the limits of data rate or sample rate reduction that can be accomplished by sharp cutoff band limiting filters in a PCM data acquisition system. The results with practical analog filtering techniques are compared with those possible with digital filtering techniques. A typical 2:1 reduction in telemetry bit rate is shown to be practical using digital vs analog techniques. The resultant sample rates as low as 2.5 times the filter cutoff frequency has implications in the reconstruction algorithms which are also discussed. It is shown that by using practical and appropriate interpolation techniques or sample rate multiplication processes the data fidelity can be preserved. Thus the data user is assured that no information is being lost.
    • Rotary Head Recorders in Telemetry Systems

      Dunn, Wiley E.; Fairchild Weston Systems Inc. (International Foundation for Telemetering, 1989-11)
      Although magnetic recording devices employing rotary head technology have been around for many years, specific products were not developed with the bit error performance to satisfy the instrumentation recorder needs of the telemetry community. Only recently have a number of new products and new product development programs materialized which offer positive indications that telemetry systems will soon benefit from the higher data rates and storage capacities. The lack of standards in development of rotary head technology has led to development of a variety of design approaches by various manufacturers and system designers. If this trend continues, the telemetry community will not enjoy the media compatibility which has contributed so much to the success of the IRIG instrumentation recorder. The ability to remove a tape recorded on one vendors recorder and replay the tape on a different ground station containing a second vendors recorder is a capability that should be retained with the advent of the new machines. Two standards have evolved defining tape characteristics and the format of information on tape for instrumentation rotary head recorders. For the instrumentation tape media to be truly transportable between telemetry ground stations, standard signal and data formal interfaces must also be developed.
    • Advanced Concepts for Telemetry Data Systems

      Pritchard, James A.; National Aeronautics and Space Administration (International Foundation for Telemetering, 1989-11)
      Current telemetry data processing systems capabilities will have to be improved by as much as three orders of magnitude in order to handle the expected data rates of the Space Station era. National Aeronautics and Space Administration (NASA) processing systems can currently process telemetry data at an average input rate of about 100K bits per second while Space Station era data rates will average about 100M bits per second and could have peak rates of up to 1200 M bits per second. In order to meet the challenge of developing telemetry systems for processing high rate data at a reasonable cost, data processing and distribution systems must be data driven as opposed to being resource scheduled. If a system is to be data driven, data structures must contain a mechanism for routing of the data to its intended destination. Packet telemetry systems have been developed for the purpose of processing and routing telemetry data at higher rates than conventional time division multiplexed systems. Packet telemetry data standards are being developed by the international Consultative Committee for Space Data Standards (CCSDS) in order to facilitate development of packet telemetry systems both within NASA and international space agencies as well as for inter-agency cross support situations. These CCSDS Advanced Orbiting Systems (AOS) standards specify the overall architectural framework of future packet telemetry systems. The CCSDS AOS standard defines a CCSDS Principal Network (CPN) which covers the on-board, space link and ground systems and provides for asynchronous (e.g., Telemetry and Internetworking) and isochronous (e.g., Audio and Video) data transport services utilizing CCSDS Packets and Virtual Channels. In order to achieve efficient use of the limited resources of the space link, CCSDS Packets are multiplexed on to CCSDS Virtual Channels for transmission through the space link. This paper will mainly discuss changes to ground telemetry processing systems currently in use (such as the Packet Processor (PACOR) System), future systems under development (such as the Space Station Information System(SSIS) and the Customer Data Operations System (CDOS)), and how the CCSDS standards relate to these systems.
    • Compact Memory Module for High Performance Applications

      Chitty, R.; Capote, L.; Kaschmitter, J.; Tuckerman, D.; Fairchild Space Company; nCHIP, Inc. (International Foundation for Telemetering, 1989-11)
      A common problem in many space applications is the need for a reliable large memory capacity in a light weight, low volume package. The Fairchild Space Company (FSC) is developing a high density static RAM based on VHSIC Hybrid Wafer Scale Integration (HWSI) technology for use in high reliability applications. Advances in interconnect technology and electronic packaging result in a bit density of 2.1 x 10⁷ bits per cu. in. Emphasis will be placed on the general benefits to the aerospace community of the device's high packing density and configurable 16, 32, and 64 bit word width. A specific application of the 64 Megabit SRAM module in the Fairchild Solid State Recorder is discussed to illustrate the performance advantage over conventional single chip and less conventional multi-chip package technologies.
    • Using AI To Simulate Spacecraft and Automate operations

      Golden, Marilyn; Ortiz, Dennis; Ford Aerospace (International Foundation for Telemetering, 1989-11)
      Software simulation is playing an increasing role in the entire product development life cycle. However, traditional software simulation tools do not fit easily into the intergrated environment required. Recent AI techniques can alleviate the problems involved with intergrating simulation tools through out the development cycle so they can then become the basis for automated operations after the systems have been deployed. Ford Aerospace has developed a software tool that interacts with the user to model the problem domain. The tool automatically provides a continuous, time-sliced simulation fo the modeled domain's behavior. Model-building is object oriented and requires no programming. The system uses a series of integrated graphic screens, controlled by mouse selection, and therefore requires only a few hours of training. Once developed, the domain model can serve as the knowledge base for trade studies made during the development process for V+V of the system during the testing phases and for automated analysis and fault diagnosis and correction during operations. Most complex functions required to be performed on the gorund to control spacecraft can be automated. The paper will discuss how PARAGON can be used (1) to help the spacecraft designer during the development process indentify the most useful set of telemetry points for TT+, (2) to help the test engineer validate performance against traditional software simulations and hardware prototypes, (3) to train and rehearse operators so a wide-variety of scenarios can be experienced interactively rather than a few pre-planned situations, and (4) to help the operator diagnose and correct complex, unexpected, anomalous situations.
    • Specifying and Evaluating PCM Bit Synchronizers

      Carlson, John R.; Aydin Computer and Monitor Division (International Foundation for Telemetering, 1989-11)
      As we enter the 1990's PCM Bit Synchronizers continue to be of major importance to data recovery systems. This paper explains the specification of PCM Bit Synchronizers and provides insight into real world performance requirements and verification methods. Topics include: Theoretical bit error ratio for wideband versus prefiltered data, probability of cycle slip, jitter, transitition density and transition gaps. The merits of multiple and/or adaptive, loop bandwidth, input signal dynamic range, and embedded Viterbi decoders are also discussed. Emphasis is on the new high data rate applications, but the concepts apply to the specification of bit synchronizers in general.
    • Prototype Architecture for a VLSI Level Zero Processing System

      Shi, Jianfei; Grebowsky, Gerald J.; Horner, Ward P.; Chesney, James R.; RMS Technologies, Inc.; Data Systems Technology Division; NASA, Goddard Space Flight Center (International Foundation for Telemetering, 1989-11)
      While the complete process of preparing telemetry data for delivery to NASA's customers requires a number of steps or levels (level 0,1,2...etc.), the initial processing, generally referred to as Level Zero Processing (LZP), poses a real technical challenge for NASA in the 1990s Space Station Freedom era. This challenge is the result of requirements to provide real-time or near real-time LZP products at rates up to 150 Mbps. In addition, increased use of sophisticated data formats places even more demand on NASA's future ground telemetry data systems. A new high speed Level Zero Processing system approach has been proposed for the Space Station Information System. By using a new processing algorithm, the complexity of database management necessary for reconstructing payload data streams has been significantly reduced. This new approach is based on the state-of-art distributed real-time processing and VLSI hardware systems and offers potential processing rates up to 150 Mbits per second (Mbps).
    • Advanced Orbiting Systems Test-Bedding and Protocol Verification

      Noles, James; De Gree, Melvin; The MITRE Corporation; National Aeronautics and Space Administration (International Foundation for Telemetering, 1989-11)
      The Consultative Committee for Space Data Systems (CCSDS) is developing a set of communications protocols for Advanced Orbiting Systems (AOS). The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are cooperating in an effort to extensively validate these AOS protocols. This paper describes the techniques and facilities being used to perform this validation. Validation of the AOS protocols consists of (1) developing a formal specification of the protocols using a standard formal definition technique (FDT), (2) developing implementations of the protocols, and (3) remote testing of the implementations. From the FDT specifications, each agency is developing independent implementations which are consistent with the FDT specifications of the AOS protocols. Errors, omissions, or discrepancies detected during the development of the FDT specification and the implementation will be reported to the CCSDS and changes to the main specification will be suggested. The independent implementations will be extensively tested locally by the developing agency and then remotely tested through a cooperative test setup between the agencies. The implementations will interact to communicate between the agencies thus providing proof that the FDT specifications are sufficiently specific to be interpreted by everyone in the same way. Significant variations in the interpretations will result in feedback to the CCSDS and any needed changes to the main specification will be suggested. The AOS protocols are divided into four categories: Path, Space Link ARQ Protocol (SLAP), Space Link (SL), and Management. Each agency has agreed to be either the leader or support agency for each of the categories. NASA has agreed to be leader for the validation of the SLAP and SLS categories while ESA has agreed to lead in the validation of the Path and Management categories. Testbeds at the European Space Research and Technology Centre (ESTEC) in Noordwijk, Holland and at the MITRE Corporation in McLean, Virginia have been constructed for the development of FDT specifications and AOS protocol implementations. Communications facilities are being obtained which will connect these testbeds. This paper describes these testbeds, the AOS FDT specifications, the protocol implementations being developed, and the results expected from the tests performed.
    • Telemetry Data Storage Systems Technology for the Space Station Freedom Era

      Dalton, John T.; NASA/Goddard Space Flight Center (International Foundation for Telemetering, 1989-11)
      NASA'S Space Station Freedom and the Earth Observing System, due to be operational in the mid-1990's, will provide scientists the vehicles to deploy an unprecented number of data producing experiments, including advanced imaging instruments with high spatial and spectral resolution. Peak down-link data rates are expected to be in the 500 megabit per second range, and the daily volume of science data could reach 2.4 terabytes. Such startling requirements have stimulated development efforts in high rate on-board recorders, and inspired an internal NASA study to determine if economically viable data storage solutions are likely to be available to support the ground data transport segment. This paper summarizes the mission and system drivers for telemetry data recording and storage capabilities, and provides an overview of NASA efforts to prototype advanced storage systems.
    • Software for the Concurrent Based Telemetry Data Handling System (TDHS)

      Bosik, Edward R.; Hutchinson, Michael P.; White Sands Missile Range; Fairchild Weston (International Foundation for Telemetering, 1989-11)
      The TDHS, designed and built for WSMR (White Sands Missile Range), is hosted by a Concurrent 3280 Processor. The TDHS software is a combination of new software designed specifically for this system and conversion of software that Fairchild Weston offers as standard products on other host computers. The system software is based on a menu system and provides a friendly user interface. The software supports the latest EMR products (including an 8715 Preprocessor and an 8470 Digital Discriminator), intercomputer data transfer and very high speed storage of data to disk and tape. TDHS also provides quick-look data display during real-time on strip charts and Concurrent based displays. Data processed by the Concurrent host can be sent back to the 8715 for distribution in the same manner as the incoming telemetry data. Immediately after data acquisition all data can be viewed on the color graphic and alphanumeric terminals.
    • Real-Time Test Data Processing System

      White, Allan P.; Dean, Richard K.; Veda Incorporated (International Foundation for Telemetering, 1989-11)
      The U.S. Army Aviation Development Test Activity at Fort Rucker, Alabama needed a real-time test data collection and processing capability for helicopter flight testing. The system had to be capable of collecting and processing both FM and PCM data streams from analog tape and/or a telemetry receiver. The hardware and software was to be off the shelf whenever possible. The integration was to result in a stand alone telemetry collection and processing system.
    • Amarrm Warhead Compatible Telemetry

      Powell, David G.; Pacific Missile Test Center (International Foundation for Telemetering, 1989-11)
      During the final stages of the AMRAAM Full Scale Development effort a requirement for a miniature warhead compatible instrumentation system was established. Internal missile volume was not available to house the system but volume was identified within the external wiring harness cover. The system was required to have significant data handling capability and encryption, and had to withstand a severe environment on a small power budget. Several technologies were developed at the Pacific Missile Test Center to meet this challenge including Application-Specific Integrated Circuits (ASIC), surface mount technology, and thick and thin film hybrid microcircuits. In addition the state-of-the art in transmitters and power converters was stretched. The result was an encrypted PCM telemeter with 2 watt transmitter and antenna all in the missile wiring harness cover (along with the wires!)
    • The Rotor-Signal-Module of MFI90

      Holland, Rainer; DLR Institut für Flugmechanik (International Foundation for Telemetering, 1989-11)
      This paper presents special measuring equipment designed for acquiring rotor data from a BO105 helicopter. Some aspects of hardware design, especially in the field of digital data acquisition and processing will be discussed. On this occasion the limited space available on the rotor hub must be taken into consideration. The rotor-signal-module also has to function in the future measurement system MF190. The paper concludes with the presentation of a method of calibrating the measurement values from the rotor blades. In this connection measured rotor data will be compared with results obtained by a nonlinear helicopter computer simulation. This represents one possibility to check the data quality.