• Binary PCM/FM Tradeoffs Between Spectral Occupancy and Bit Error Probability

      Law, Eugene L.; NAWCWPNS (International Foundation for Telemetering, 1994-10)
      The bit rates of telemetry systems are increasing rapidly. Higher bit rates occupy more spectra and result in decreased link margin. The major signal parameters that affect the spectral occupancy and bit error probability (BEP) of binary pulse code modulation (PCM)/frequency modulation (FM) signals are the bit rate, code, premodulation filter, and peak deviation. The measured spectral occupancy is also affected by the spectrum analyzer (or other measurement equipment) settings. Additional parameters that affect the BEP include the receiver intermediate frequency (IF) filter, the FM demodulator, and the bit detector. This paper will present the effects of these parameters on the measured 99% and -60 dBc bandwidths and the BEP of binary PCM/FM telemetry signals. Normalized BEP and bandwidth curves will be presented.
    • CARD-BASEDTELEMETRY RECEIVERS

      Porter, Jim; Meyers, Tom; SEMCO (International Foundation for Telemetering, 1994-10)
      Embedded "Card-Based" receivers are one of the latest innovations in telemetry reception. These products provide substantial power and flexibility in a small form factor (one slot, PC or VME). In many applications they are a cost effective alternative to conventional telemetry receivers. This paper analyzes currently available products with regard to their features, capabilities, and performance, as well as highlighting typical applications.
    • CCSDS Data Link Service Allocation for MIL-STD-1553B Bus Architecture on Small Payloads

      Minnix, Timothy Otto; Lujan, Manuel, Jr.; New Mexico State University (International Foundation for Telemetering, 1994-10)
      There has been much interest recently in the possibility of using the NASA Tracking and Data Relay Satellite System (TDRSS) instead of proprietary ground stations in supporting small space payload communications. These payloads operate on fairly low power and do not use the sophisticated tracking equipment standard on more complex user spacecraft. This paper is part of a feasibility study for such use of TDRSS, and focuses on the effect of the method of providing the Grade-2 data link layer services specified in Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations upon a hypothetical spacecraft using a MIL-STD-1553B polled data bus as the backbone of its onboard LAN. In particular, one case in which the 1553B bus controller, assumed to be some Intel 80X86 microprocessor, provides all CCSDS services will be contrasted with another where these services are split between the bus controller and a device which interfaces between the spacecraft LAN and the TDRSS Return Service spacelink. The comparison will be made for a 15 orbit/day scenario using a small helical antenna with a comparatively wide beamwidth. The main performance criteria considered here are end-to-end data throughput and expected delays, along with required buffer sizes for the LAN. Also, it may be noted that the data rate of the TDRSS return link and the size of the sliding window used for flow and error control will have a large impact on the required values for the chosen criteria, and so choices for these parameters significantly affect the outcome of any system service comparison. The two LAN types will be modeled and analyzed using NETWORK II.5. This simulator allows tracking of the number of packets read into LAN memories and sent down from the payload to ground via TDRSS, as well as accurately modeling the delays involved with data processing and transmission over the link.
    • Chinese New Telemetry Onboard System

      Jie, Shi Chang; China Aerospace Corporation (International Foundation for Telemetering, 1994-10)
      This paper at first gives a brief historical review of Chinese development of telemetering onboard system and then make a brief introduction of new onboard system from several respects.
    • The Common Airborne Instrumentation System Program Management Overview

      Brown, Thomas R., Jr.; Naval Air Warfare Center, Aircraft Division (International Foundation for Telemetering, 1994-10)
      The Department of Defense, through a Tri-Service Program Office, is developing the Common Airborne Instrumentation System (CAIS) to promote standardization, commonality, and interoperability among aircraft test instrumentation systems. The advent of CAIS will change how the DoD test community conducts business. The CAIS program will allow aircraft test and evaluation facilities to utilize common airborne systems, ground support equipment, and technical knowledge for airborne instrumentation systems. The CAIS Program Office will conduct requirements analyses, manage system upgrades, and provide full life cycle support for this system. It is initiating several requirements contracts to provide direct ordering opportunities for DoD users to easily procure defined test instrumentation hardware. The program office will provide configuration management, inventory control, maintenance support, system integration, engineering support, and software management. In addition, it will continue to enhance the current system and develop new items to meet future requirements. Where existing equipment provides added benefit, this equipment may be added to the official CAIS family.
    • COMPACT HIGH-SPEED DISK RECORDER

      Bougan, Timothy B.; Science Applications International Corporation (International Foundation for Telemetering, 1994-10)
      In order to meet the high-speed and high-density recording requirements for today's development and testing environments, we are seeking to merge the cutting edge technologies of tiny, high-performance disk drives and field programmable gate arrays (FPGAs) to build a high-speed compact disk recorder (CHSDR). Specifically, we designed, built, and tested a multi-drive controller that handles the interleaving of data to eight inexpensive IDE drives. These drives and controller comprise a "cell" capable of transferring data at 2.45 MB/sec (4 to 5 times the rate of a single drive). Furthermore, these "cells" can be run in parallel (with a single controller interleaving data between the cells). This "tree" effect multiplies the data rate by the number of cells employed. For example, 8 cells (of 8 drives each) can reach nearly 20 MB/second (sustained) and can be built for less than $30,000. The drives we used are the size of match boxes (the Hewlett Packard KittyHawk). These tiny drives hold 42 megabytes each and can withstand 150 Gs while operating. The cell controller is a Xilinx 4005 FPGA. Furthermore, we've designed a 120 MB/sec RAM FIFO to buffer data entering the system (to account for unavoidable drive seek latencies). In short, the compact high-speed disk array is a small, relatively low cost recording solution for anyone requiring high data speed but modest data volume. Missile shots, nuclear tests, and other short-term experiments are good examples of such requirements.
    • A COMPACT, LIGHTWEIGHT, LOW POWER, MULTI-FUNCTION TELEMETRY RECEIVER/COMBINER SYSTEM PROVIDES "HANDS OFF" AUTOMATION FOR SYSTEMS COST REDUCTION

      O'Cull, Douglas C.; Microdyne Corporation (International Foundation for Telemetering, 1994-10)
      With the increased concerns for reducing cost and improving reliability in today's telemetry systems, many users are employing simulation and automation to guarantee reliable telemetry systems operation. This places an increased demand on the remote capabilities of the equipment used in the telemetry system. Furthermore, emphasis has been placed on the ability to decrease the space and power consumption of the telemetry system to facilitate transportability of the a single telemetry system to multiple sites. Finally, today's telemetry systems demand that all equipment provide multiple functions to provide the maximum performance for the lowest system cost.
    • COMPUTER-AIDED DESIGN OF CIRCULARLY-POLARIZED CONFORMAL MICROSTRIP PATCH ANTENNA FOR TELEMETRY APPLICATIONS

      Wu, Doris I.; Rieger, James (International Foundation for Telemetering, 1994-10)
      Planar microstrip antennas are desirable in many telemetry applications because they are small in size, light in weight, and conformal to most surfaces. The design and optimization of circularly-polarized omnidirectional microstrip arrays using a new software simulation tool are discussed in this paper. Critical design issues such as the optimization of each array element for circular polarization and the minimization of mutual couplings as well as feed network mismatch are examined. The software tool, which consists of a novel graphical user interface and a full-wave numerical simulator for a flat mounting surface, provides a testbed environment for the user to explore new designs as well as optimizing existing designs. Using this tool, the design of several wraparound arrays with different mounting cylinder radii are presented. Comparisons between measured and simulated data for two S-band 8-element wraparound arrays are also presented.
    • CONCEPTUAL DESIGN OF A MODIFIED XBT TELEMETRY SYSTEM FOR USE IN THE OCEANS OF TITAN

      Mitchell, B. J.; The Johns Hopkins University (International Foundation for Telemetering, 1994-10)
      Current theories concerning the surface of Titan postulate the existence of large, possibly oceanic, bodies of liquid ethane/ammonia plus various other chemicals. ESA's Huygens probe is designed to gather oceanographic data on Titan. If the postulated oceans or lakes do exist, follow up missions of an oceanographic nature will be planned. This paper provides a concept for a modified XBT (eXpendable Bathymetric Thermograph) probe design that will provide more data than just temperature as a function of depth. By judicious use of acoustic telemetering links, data on the sound speed profile and constituents of the ocean can be obtained. The exo-oceanographic data collected will have important ramifications for oceanographic studies on Earth.
    • Control of a Remote Receiving Station and Data Processing at RA Range Hebrides

      Mackenzie, Donald; Fielding, Richard; Serco, RA Range Hebrides; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      The Royal Artillery Range (RA Range) is the British Army's weapons practice range in the Outer Hebrides of Scotland. The large sea range is also used by the Royal Air Force and Royal Navy for new weapons system evaluation and in service practice firing. This paper describes the telemetry facility comprising of two prime sites separated by 40 miles of open sea. Tracking antennas and receivers are at the remote island site of St Kilda with data processing and control at the Range Control Base (RCB), Benbecula. To improve operational capabilities and effectiveness, full remote control and monitoring of the multiple receivers and combiners has been installed. Radar tracking outputs are processed in the telemetry computer to produce individual antenna pointing demands.
    • 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.
    • DATA ACQUISITION, ANALYSIS, AND SIMULATION SYSTEM (DAAS)

      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.
    • A DATABASE-DRIVEN SOFTWARE SYSTEM FOR SATELLITE TELEMETRY DECOMMUTATION

      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.
    • DEVELOPMENT OF AN OBJECT-ORIENTED SOFTWARE APPLICATION TO PROVIDE A TRANSPARENT INTERFACE BETWEEN SPACE NETWORK OBJECTS AND A TELEMETRY SYSTEM FOR TRAINING

      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.
    • DISCRETE EVENT SIMULATION OF THE EOS-AM1 SCIENCE FORMATTING EQUIPMENT

      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.