• Data Acquisition System Central Multiplexer

      Anderson, William; Carro, Eduardo; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      The Central Multiplexer is a versatile data multiplexer designed to address emerging test requirements for recording data from many sources on digital rotary head recorders at high data rates. A modular design allows easy reconfiguration for airborne or laboratory use; simultaneous data input from 63 sources of data in any combination of PCM commutators, ARINC 429 buses, ARINC 629 buses, MIL- STD-1553 buses, and general-purpose high-speed serial data packets; simultaneous, independent programmable outputs to high-speed digital data recorders, quick-look displays, and engineering monitor and analysis systems; and setup and control from a remote panel, a dumb terminal, a laptop personal computer, a standalone test system, or a large control computer.

      Baca, Dawnielle C. (International Foundation for Telemetering, 1994-10)
      The Data Acquisition, Analysis, and Simulation System (DAAS) is a computer system designed to allow data sources on spacecraft in the Flight System Testbed (FST) to be monitored, analyzed, and simulated. This system will be used primarily by personnel in the Flight System Testbed, flight project designers, and test engineers to investigate new technology that may prove useful across many flight projects. Furthermore, it will be used to test various spacecraft design possibilities during prototyping. The basic capabilities of the DAAS involve unobtrusively monitoring various information sources on a developing spacecraft. This system also provides the capability to generate simulated data in appropriate formats at a given data rate, and to inject this data onto the communication line or bus, using the necessary communication protocol. The DAAS involves Serial RS232/RS422, Ethernet, and MIL-STD-1553 communication protocols, as well as LabVIEW software, VME hardware, and SunOS/UNIX operating systems.

      Culver, Randy; LORAL FEDERAL SYSTEMS (International Foundation for Telemetering, 1994-10)
      Satellite Telemetry can be characterized as having relatively low bandwidths, complex wavetrains, and very large numbers of measurands. Ground systems which monitor on-orbit vehicles must process, analyze, display, and archive the telemetry data received during contacts with the satellites. Data from perhaps thousands of individual measurands must be extracted from very complex wavetrains and processed during a live contact. Most commercially available telemetry systems are not well suited to handling satellite wavetrains because they were built for range telemetry and flight test applications which typically deal with limited numbers of measurands. This paper describes the design of a software system which was built specifically to process satellite telemetry. The database-driven system performs full decommutation of very complex wavetrains entirely in software. The system provides for defining the satellite vehicle's telemetry in multiple databases which define the wavetrain formats, the measurands themselves, how they are to be processed, and associated data conversion and calibration information. The database accommodates the complexities typically found in satellite telemetry such as multiple wavetrain formats, embedded streams, measurand dependencies, segmented measurands, and supercommutated, subcommutated, and sub-subcommutated data. A Code Generator builds a set of control structures from the wavetrain and measurand definitions in the database. It then generates highly optimized in-line software libraries for processing the satellite vehicle's telemetry. These libraries are linked to a Server process for run-time execution. During execution, raw telemetry frames are passed to the Server which uses the libraries to decommutate, limit check, convert, and calibrate the measurand data. A Client process attaches to the Server process to allow user applications to access both raw and processed telemetry for display, logging, and additional processing.
    • Design and Use of a CCSDS - Compatible Data Unit Decoder

      O'Donnell, John; Ramirez, Jose; AYDIN; NASA (International Foundation for Telemetering, 1994-10)
      The Consultative Committee for Space Data Systems (CCSDS) formulates and publishes recommendations for space data system standards. CCSDS Recommendations define a layered data communications network along the lines of the OSI model. In the space link layer (OSI Data Link layer) fixed length blocks of CCSDS Packets are generated and multiplexed into the data field of Virtual Channel Data Units (VCDUs) in the Virtual Channel Access Sublayer. VCDUs with error correction coding become CVCDUs (coded VCDUs). CVCDUs (or VCDUs) with an attached sync marker become Channel Access Data Units (CADUs) which are transmitted on the Physical Space Channel. This paper discusses AYDIN's DEC012 Data Unit Decoder, a VMEbus circuit card which recovers Virtual Channel Data Units (VCDUs) from corrupted Channel Access Data Units (CADUs) received on the Space Link Subnet of a CCSDS-compatible space datacomm link. The module's design and operation is described along with its use in the X-ray Timing Explorer (XTE) and Tropical Rainfall Measuring Mission (TRMM) science satellite programs run by NASA Goddard Space Flight Center.
    • Design Equations for a Specified Bit Error Rate for PCM/FM+FM/FM and Optimum Bandwidths

      Carden, Frank F.; New Mexico State University (International Foundation for Telemetering, 1994-10)
      A PCM/FM+FM/FM system combines the bit sequence with the modulated subcarriers at baseband and the resultant modulates the carrier. This paper concerns the design of this composite system. Such a system combines the spectral efficiency of the analog system with the accuracy of a PCM system when needed for specific sensors and allows the direct transmission of binary computer words if necessary. The impact of the subcarriers on the bit error rate of the bit sequence is determined. Equations are given which allow the degradation of the FM/FM channels by the bit sequence to be determined. Further, it is shown in this work that as the IF bandwidth is increased above twice the bit rate, the peak deviation of the carrier by the bit sequence is no longer .35 times the bit rate. An optimum value for IF bandwidths is determined. The developed design equations allow the design of the composite system with a specified bit error rate and a specified signal to noise ratio in the subcarrier channels.
    • Deterministic Distribution of Telemetry and Other Replicated Information

      Gustin, Thomas W.; SYSTRAN Corp. (International Foundation for Telemetering, 1994-10)
      Discover how it is now possible to memory-link all man-in-the-loop and machine-in-the-loop elements, as global resources that share information at memory-access speeds, to provide a unified system paradigm that avows: "the data is there, on time, every time." Regardless of configuration, if your past, present, or future system consists of more than one computer, and it interactively mixes information sources and destinations (e.g. Telemetry data streams, I/O interfaces, information processors, etc.) to achieve a highly integrated system, then the critical path to real-time success mandates a high performance, reliable, and deterministic communications methodology. This softwareless, future technology is already successfully sharing information in other real-time markets and applications, and is ready for more challenging applications.

      Kleen, Mitchell; White, Joey; Policella, Joseph; CAE-Link Corporation (International Foundation for Telemetering, 1994-10)
      The Space Station Verification and Training Facility is using an object-oriented design methodology for software design, a rate monotonic scheduling and message passing system to support the highly distributed environment, and the Ada language to implement most of the software. One of the subsystems within the Space Station and Training Facility is the Space Network Simulator. Space Network simulators are used to provide training of ground controllers and flight crews, providing a model of real-world formats and protocols. This gives the controller the appearance of a real-world network, providing valuable training. To develop a simulation of the space network within this distributed environment, software objects are under development to dynamically simulate the existence of the space vehicle(s) and their communication components. Communication components include the on-board antennas, transponders, communication systems, and corresponding communication ground control facilities. Telemetry systems are used in the simulation to provide the control of actual data manipulation, as a function of the state of the simulated Space Network. The telemetry system automatically formats appropriate telemetry characteristics through mode and control commands. A software model is under development to provide a transparent interface between the software objects and the telemetry system, allowing the objects to execute without knowledge of the particular telemetry system in use. A transparent interface between the software and hardware, within this object-oriented methodology, reduces the propagation of change to software models as the interface requirements change.
    • The Development of Application Software for Telemetry Groundstation Remote Control and Analysis

      Peterson, Dwight M.; Naval Warfare Assessment Division (International Foundation for Telemetering, 1994-10)
      Fleet telemetry stations were established in the 1965-1972 time frame to satisfy U.S. Navy requirements for weapons system training support. These stations are currently located at the Atlantic Fleet Weapons Training Facility (AFWTF), Puerto Rico; Naval Air Station (NAS) Oceana, Virginia; the NATO Allied Missile Firing Installation (NAMFI), Crete, Greece; and White Beach, Okinawa, Japan. The mission of these telemetry stations is to collect, record, and process telemetered missile data during exercises involving ships and aircraft. The Naval Warfare Assessment Division uses the data to analyze weapons system performance during missile firing exercises conducted on fleet training ranges associated with these telemetry stations. Since these stations were originally installed, missile weaponry has advanced in sophistication, complexity, and usage. New weapons and tactics have been developed and introduced into the fleet which have not been matched by corresponding technology enhancements in the existing fleet telemetry stations. As a result, the Program Manager for Tactical Training Ranges (PMA-248) tasked the Naval Warfare Assessment Division to develop a computer-controlled telemetry ground station design capable of meeting current and future fleet training range requirements. This program involved the design, procurement, integration, and testing of telemetry ground station hardware and software required to meet fleet telemetry data collection requirements. Full Operational Capability of the first system, which was installed at AFWTF in Puerto Rico, was achieved in March of 1994. To date, the new telemetry ground station hardware and software has been used to support complex fleet training exercises, Combat System Ship Qualification Trials, Development Tests, and Operational Tests of U.S. and foreign navies. This paper will present the hardware and software design principles used to develop a computer-controlled telemetry ground station and the demonstrated performance benefits which have been realized.
    • A Dielectric Resonator Stabilized Frequency Modulation Oscillator in the S-Band

      Banghua, Zhou; Mingsheng, Huang; Xinan Electronic Engineering Institute (International Foundation for Telemetering, 1994-10)
      With the development of the airborne telemetry technique, it will be demanded that the transmitting sets on the missiles are more reliable and smaller. A frequency modulation (FM) oscillator stabilized with a dielectric resonator (DR), which can operates in the S-band directly, is presented. The FM oscillator is of simple circuit, reliable operation in the stabilization, small size, light weight and low cost. It will have a certain prospect of application in the airborne telemetry transmitting sets.

      Barringer, Bruce O.; Fairchild Space and Defense Company (International Foundation for Telemetering, 1994-10)
      Fairchild is presently developing a high-rate telemetry collection and formatting component for one of NASA’s Mission to Planet Earth’s key missions. Because of the complexity and new technology involved, discrete event simulation tools have played a key role in the development process. This paper serves as a brief introduction to this component and to the model developed with the simulation tools.

      Martin, Fredric W. (International Foundation for Telemetering, 1994-10)
      Use of top-down design principles and standard interface techniques provides the basis for a global telemetry data collection, analysis, and satellite control network with a high degree of survivability via use of distributed architecture. Use of Commercial Off-The-Shelf (COTS) hardware and software minimizes costs and provides for easy expansion and adaption to new satellite constellations. Adaptive techniques and low cost multiplexers provide for graceful system wide degradation and flexible data distribution.
    • Distributed Interactive Simulation (DIS): An Overview Of The System And Its Potential Uses

      Boyd, Edward L.; Novits, Charles S.; Boisvert, Robert A.; Encore Computers (International Foundation for Telemetering, 1994-10)
      The Distributed Interactive Simulation (DIS) concept, since its inception, has been defined into three separate but distinct areas of service. • Viewing of data in the real-time environment. • Multiple range viewing and usage of"real-time data." • Problems with the sharing of information through DIS. This paper will discuss the DIS concept and some of the various methods available to display this data to users of the system.

      Hoefener, Carl E.; Interstate Electronics Corporation (International Foundation for Telemetering, 1994-10)
      With the decline in military budgets worldwide, the need for ever more effective training is becoming apparent. The size of the armed forces is being reduced, so the remaining members have to be trained to be more effective and efficient in doing their jobs. To improve effectiveness and efficiency of performance, military training needs will be increased. Our largest training costs will be in pilot training because of the high cost of keeping aircraft in the air. When we look at the cost of training a pilot to operate in a multiplayer scenario against a large number of unfriendly aircraft and a large number of ground threats, the cost of training is tremendous. It requires a large number of personnel, aircraft and ground equipment to train a limited number of pilots. Our current Red Flag exercises can require as many as 75 aircraft in the air simultaneously plus a large number of ground threats and a large number of support personnel. This can amount to a prohibitive cost to train a limited number of pilots.
    • Divide and Conquer: Improving Post-Flight Data Processing

      Scardillo, Mike; Nisel, Mike; Perimeter Computer Systems, Inc. (International Foundation for Telemetering, 1994-10)
      This paper describes Dryden Flight Research Center's (DFRC's) transition from a mainframe-oriented post-flight data processing system, heavily dependent upon manual operation and scheduling, to a modern, distributed, highly automated system. After developing requirements and a concept development plan, DFRC replaced one multiple-CPU mainframe with five specialized servers, distributing the processing workload and separating functions. Access to flight data was improved by buying and building client server automated retrieval software that takes advantage of the local area network, and by providing over 500 gigabytes of on-line archival storage space. Engineering customers see improved access times and continuous availability (7-days per week, 24-hours per day) of flight research data. A significant reduction in computer operator workload was achieved, and minimal computer operator intervention is now required for flight data retrieval operations. This new post-flight system architecture was designed and built to provide flexibility, extensibility and cost-effective upgradeability. Almost two years of successful operation have proven the viability of the system. Future improvements will focus on decreasing the elapsed time between raw data capture and engineering unit data archival, increasing the on-line archival storage capacity, and decreasing the automated data retrieval response time.
    • Dual Function Transponder: A Data Link for the Next Generation

      DeViso, Hans; Troth, Bill (International Foundation for Telemetering, 1994-10)
      Future U.S. Navy at-sea and littoral battle group training range instrumentation requires a new, secure, high data rate link This link must be capable of providing the ranges with the capacity to increase the number of players, increase the amount of threat simulation, and allow an improved Global Positioning System (GPS) based position tracking system to be implemented This paper describes a Dual Function Transponder (DFT) capable of operating on any R-CUBED (Relay, Reporter, Responder) based range as well as any TACTS/ACMI range without modification of either range type. In addition, the DFT provides a new increased data rate capability for use by planned future ranges, enabling a dramatic increase in the number of participants as well as significantly increasing the quantity of data that can be communicated by each player. Miniaturization and programmability are the keys to this development and many of the methods used are described.

      Gaskill, David M.; ASTRO-MED INC. (International Foundation for Telemetering, 1994-10)
      This paper will examine real-time ethernet capabilities in general and will describe in detail a practical implementation of an Ethernet interface that allows commands and data to be sent to a thermal array recorder using a standard TCP/IP, Novell, or similar interface. This interface allows two types of data transmission. First, real-time data may be sent at low rates for slow speed monitoring or, second, high speed packets may be sent for storage in local FIFO memory. A header containing sample rate information allows the recorder to reconstruct the data on paper smoothly so that it has the appearance of real-time recording but is slightly delayed. In addition, normal host control commands may be interleaved with data for a complete high speed digital data system.
    • The Evolution of a Telemetry Groundstation Utilizing Today's Open Standards

      Friedman, Paul; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      Computer industry and government standards have had a profound effect on modern telemetry ground stations. Installations are no longer one-of-a-kind inflexible systems built to the specifications of a single user - meeting their needs without regard to the rest of the community. This paper will examine the effect that the evolution of significant graphics, network, operating system, and architecture standards has had on commercial telemetry ground station system products. It will also explore the issue of "open" versus proprietary architectures. The paper closes with a description of a system designed from its very inception to meet and grow with standards.

      Hazra, Tushar K.; Stephenson, Richard A.; Troendly, Gregory M.; Martin Marietta Services, Inc. (International Foundation for Telemetering, 1994-10)
      During the recent years of small satellite space access missions, the trend has been towards designing low-cost ground control centers to maintain the space/ground cost ratio. The use of personal computers (PC) in combination with high speed transputer modules as embedded parallel processors, provides a relatively affordable, highly versatile, and reliable desktop workstation upon which satellite telemetry systems can be built to meet the ever-growing challenge of the space missions today and of the future. This paper presents the feasibility of cost effective, high performance ground systems and a quantitative analysis and study in terms of performance, speedup, efficiency, and the compatibility of the architecture to commercial off the shelf (COTS) tools, and finally, introduces an operational high performance, low cost ground system to strengthen the insight of the concept.
    • GPS as a Telemetry Sensor

      Qishan, Zhang; Xianliang, Li; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 1994-10)
      GPS is required in today's vehicle tracking and navigation applications. The Navigation Satellite Timing and Ranging (NAVSTAR GPS) is an all-weather. Radio based, satellite navigation system that enables users to accurately determine 3-dimensional position, velocity and time. So it is an intelligent sensor intended to be used as a component in a system for public service.

      Rucinski, Gary; BBN Systems and Technologies (International Foundation for Telemetering, 1994-10)
      In recent years the extension of interactive simulation technology to involve simulators and live vehicles from geographically dispersed sites has produced a demand for high-bandwidth communication networks that can provide guaranteed quality of service (e.g., insured availability of bandwidth and upper bounds on end-to-end delay). This paper reviews the requirements distributed interactive simulation places on the communications infrastructure and describes the Defense Simulation Internet (DSI), a network developed by the Advanced Research Projects Agency to support distributed interactive simulations. Key features of the DSI are: more than 120 participating sites spanning Europe, the United States and Asia; use of a resource reservation mechanism to provide guaranteed quality of service; and support for communication between classified sites. Furthermore, the paper describes the internetworking protocols used in the DSI to provide guaranteed quality of service and to support transmission of classified communications. Other topics discussed in the paper are research efforts that anticipate increased load on the DSI and the relevance of the technology to the integration of the telemetry range and distributed interactive simulations.