• A New Approach to Telemetry Data Decomposition and Analysis Based on Large-Capacity Semiconductor RAM

      Jun, Zhang; Qishan, Zhang; Zhihui, Zhang; Jian, Huang; Beijing University of Aeronautics & Astronautics (International Foundation for Telemetering, 1993-10)
      With the development of microelectronics and computer technology, telemetry computer systems are demanded to provide larger storage capacity and higher storage data rate than ever before. This paper fully considers various factors of a high-speed PCM fiber-optic telemetry system such as data format, data rate, data storage, the width of data storage, storage data rate. All these considerations lead to a new scheme with a semiconductor RAM and a dedicated program as its basic idea. This scheme chooses 1Mbits or 4Mbits static-RAM chips to implement the telemetry data storage device with a total capacity of 4Mbytes, 16Mbytes, or 64Mbytes. The software running on COMPAQ 386/25M or its compatibles is written in Turbo C 2. 0 to fetch, decompose, display and process data stored in the large-capacity RAM. The main task of the system processing software is to identify the flag words of frame sync-code -pattern and then demultiplex the data into separate channel data to be stored in the disk. Besides the ability to recognize specific data format, the software can also rectify data confusion to some extent. The scheme has already been proved to be efficient to receive large capacity of data with features of high data rate, high data storage in a short time.

      Lloyd, Joseph W. Jr (International Foundation for Telemetering, 1993-10)
      Desktop Processors (IBM PC, PC-compatible, and Macintosh) have made a major impact on how the Naval Air Warfare Center Aircraft Division (NAWCAD}, Patuxent River engineering community performs their work in aircraft weapons tests. The personal processors are utilized by the flight-test engineers not only for report preparation, but also for post-flight Engineering Unit (EU) data reduction and analysis. Present day requirements direct a need for improved post-flight data handling than those of the past. These requirements are driven by the need to analyze all the vehicle's parameters prior to the succeeding test flight, and to generate test reports in a more cost effective and timely manner. This paper defines the post-flight data distribution system at NAWCAD, Patuxent River, explains how these tasks were handled in the past, and the development of a real-time data storage designed approach for post-flight data handling. This engineering design is then described explaining how it sets the precedence for NAWCAD, Patuxent River's future plans; and how it provides the flight-test engineer with the test vehicle's EU data immediately available post-flight at his desktop processor.
    • Analysis of Frequency Stabilization and Modulation of Airborne Telemetry Transmitter

      Xizhou, Zhang; Jun, Yao; Xinan Electronic Engineering Institute (International Foundation for Telemetering, 1993-10)
      This paper analyzes the feature of frequency stability and modulation of airborne telemetry transmitters. According to the characteristic of telemetry information transmission, several methods for frequency stabilization and modulation are briefly compared. Emphasis is given to discuss frequency dividing phase- locked frequency modulation and on-off keying modulation and FM/on- off keying double modulation. With the view of raising frequency stability and modulation sensibility, extending the linear range of modulation, the contradiction between frequency stabilization and modulation should be coordinated properly. In addition, a compatible method between conventional telemetry channel and super fast signal telemetry channel is introduced. A satisfactory result has been acquired with those views and methods used in engineering application.
    • Space-based Concepts to Support the Tactical Weather Users

      Sheets, K. Yvonne; Bennett, Roger; SPARTA, Inc. (International Foundation for Telemetering, 1993-10)
      Recent military theater operations such as Desert Storm have underscored the need for additional support for theater users. The needs of specific user communities are varied, and it is appropriate to examine those needs and develop system concepts which can enable the tactical community to more effectively perform their mission. This paper examines the needs and requirements of the tactical weather community and how additional space-based assets could be used to increase the tactical mission effectiveness. The approach investigated is to augment the current military meteorological satellite program, DMSP, which operates in low earth orbit with a geosynchronous platform capable of data collection and dissemination within the theater. This approach has several advantages, including the ability to provide focused, long-term coverage over the theater, with real-time downlink directly to the tactical user. One of the goals of the study was to determine what combinations of sensors and communications services might be provided from a smaller satellite on the order of 1000 lbs. This study was performed to evaluate alternatives to providing the tactical military user with space-based environmental monitoring information as an augmentation to the Defense Meteorological Satellite System (DMSS). The effort was driven by the most recent requirements, the MAC SON 211-89 Tactical Weather Observing System (TWOS) and MAC SON 216-89 Tactical Forecast System (TFS). Emphasis on the study was the focus on geosynchronous augmentations to the current set of DMSS satellites, which included climatical scenarios and requirements analysis, as well as sensor technologies assessments.

      Yang, Kent; Wong, Cecelia; Loral Instrumentation (International Foundation for Telemetering, 1993-10)
      With the ever increasing need for faster data rates and the emergence of faster network interfaces such as Fiber Distributed Data Interface (FDDI), the task of adding new network interfaces to a telemetry system and supporting existing ones is becoming increasingly more complex. This complexity can be eliminated if the data acquisition hardware and software allows new network interfaces to be easily integrated into a telemetry system. It is the purpose of this paper to address the issues involved when dealing with multiple, heterogeneous, networking environments in telemetry systems. The paper will show how the use of flexible telemetry hardware and software will simplify the integration of new networks into an existing system, and how this flexibility can allow data acquisition applications to take advantage of a heterogeneous network.
    • Instrumentation and Telemetry Systems for Free-Flight Drop Model Testing

      Hyde, Charles R.; Massie, Jeffrey J.; NASA Langley Research Center (International Foundation for Telemetering, 1993-10)
      This paper presents instrumentation and telemetry system techniques used in free-flight research drop model testing at the NASA Langley Research Center. The free-flight drop model test technique is used to conduct flight dynamics research of high performance aircraft using dynamically scaled models. The free-flight drop model flight testing supplements research using computer analysis and wind tunnel testing. The drop models are scaled to approximately 20% of the size of the actual aircraft. This paper presents an introduction to the Free-Flight Drop Model Program which will be followed by a description of the current instrumentation and telemetry systems used at the NASA Langley Research Center, Plum Tree Test Site. The paper describes three telemetry downlinks used to acquire the data, video, and radar tracking information from the model. Also described are two telemetry uplinks, one used to fly the model employing a ground based flight control computer and a second to activate commands for visual tracking and parachute recovery of the model. The paper concludes with a discussion of free-flight drop model instrumentation and telemetry system development currently in progress for future drop model projects at the NASA Langley Research Center.

      Shaver, John W.; US Army Electronic Proving Ground (International Foundation for Telemetering, 1993-10)
      TERIS is a CTEIP (Central Test and Evaluation Investment program) project to provide wideband communications facilities between major ranges and laboratories economically and reliably. TERIS uses existing modern technology, off-the-shelf hardware and software, and leased commercial telephone facilities, Nine ranges and two laboratory facilities have been surveyed to determine costs and feasibility of connecting the TERIS. An initial three-node network is planned to be operating in early 1994.

      Richard, Gaetan C.; DECS, Inc (International Foundation for Telemetering, 1993-10)
      Two different types of tracking feeds are currently used in the majority of telemetry tracking antenna systems when autotrack operation is required. They are of the conical scanner or of the single channel monopulse family and they employ well known technologies. In broadband applications, these feeds all suffer from the same inherent degradation in efficiency caused by their inability to maintain a constant crossover loss value and by their failure to properly illuminate the reflector. In high dynamics situations they can also generate unwanted and sometimes detrimental modulation whenever on-axis tracking is not maintained. In addition, currently available versions of the conical scanner are not capable of high scan rates or of scan rate agility and they are ill-suited for use in tracking systems based on non-orthogonal axes positioners. This paper describes a new high efficiency tracking feed system based on proven conical scanner technology. Its design incorporates features such as variable crossover, steerable beam, high scan rates, scan rate agility as well as stable reference coordinate system. In addition to these features, this new feed is also capable of delivering, in all but one operational category, levels of performance superior to that achievable to date by any other implementation of the conical scanner or of the single channel monopulse technology.

      Goldsmith, T. A.; Kephart, S. R.; McDonnell Douglas Aerospace; Gulton Data Systems (International Foundation for Telemetering, 1993-10)
      Given the small size of hit-to-kill interceptor test vehicles currently under development, volumetric limitations mandate using the experimental vehicle's telemetry system during vehicle ground level acceptance and environmental testing to gather performance data, in addition to the primary function of successfully gathering and transmitting data during the test flight. In small, lightweight test interceptors, volume and mass become major telemetry system design considerations. In this paper we describe a system engineering approach to determine the key requirements and calculate some of the critical design parameters necessary for the successful design and development of a high data rate wide band FM Pulse Code Modulation (PCM) airborne telemetry system.

      Ritter, Thomas M.; Pratt & Whitney CEB (International Foundation for Telemetering, 1993-10)
      Pulse Code Modulation (PCM) data systems are used extensively in testing aircraft all over the world. These systems can be tailored to almost any set of measurement requirements using flexible, modular equipment available from several sources. This paper describes a system assembled from readily available components manufactured in the United States that is being used to certify a Russian aircraft flying in The Commonwealth of Independent States. The system features distributed data acquisition, programmable signal conditioning and PCM encoding modules, multi-channel temperature and pressure scanners and real time data displays on board the aircraft. The impact of U.S. export controls and our experience to date is also discussed.

      Smith, Quentin D.; CSTI (International Foundation for Telemetering, 1993-10)
      As technology progresses we are faced with ever increasing volumes and rates of raw and processed telemetry data along with digitized high resolution video and the less demanding areas of video conferencing, voice communications and general LAN-based data communications. The distribution of all this data has traditionally been accomplished by solutions designed to each particular data type. With the advent of Asynchronous Transfer Modes or ATM, a single technology now exists for providing an integrated solution to distributing these diverse data types. This allows an integrated set of switches, transmission equipment and fiber optics to provide multi-session connection speeds of 622 Megabits per second. ATM allows for the integration of many of the most widely used and emerging low, medium and high speed communications standards. These include SONET, FDDI, Broadband ISDN, Cell Relay, DS-3, Token Ring and Ethernet LANs. However, ATM is also very well suited to handle unique data formats and speeds, as is often the case with telemetry data. Additionally, ATM is the only data communications technology in recent times to be embraced by both the computer and telecommunications industries. Thus, ATM is a single solution for connectivity within a test center, across a test range, or between ranges. ATM can be implemented in an evolutionary manner as the needs develop. This means the rate of capital investment can be gradual and older technologies can be replaced slowly as they become the communications bottlenecks. However, success of this evolution requires some planning now. This paper provides an overview of ATM, its application to test ranges and telemetry distribution. A road map is laid out which can guide the evolutionary changeover from today's technologies to a full ATM communications infrastructure. Special applications such as the support of high performance multimedia workstations are presented.
    • Integrated Satellite Control Open System Architecture Design Standards

      Holstein, Dennis K. (International Foundation for Telemetering, 1993-10)
      Design standards defined in this paper provide the framework to implement an open system architecture to achieve the interoperability requirements for integrated satellite control directed by USCINCSPACE. Ground segment space operations that implement these standards will provide the capability to eliminate the artificial barriers between mission unique ground systems that operate in a stove-pipe manner today. Through common support equipment and advanced workstations, operator cross training will become unnecessary. To implement interoperability, it is necessary to define standard physical, electrical, and communication interfaces and protocols, so components from different manufactures will operate together. Implementation of these standards tends to build on the natural infrastructure of today's satellite operation center and maximize the reuse of common user components for satellite control, mission payload operations and force management. The infrastructure concept uniquely blends the requirements for providing a single operator the capability to perform all tasks for these missions at a single workstation. Prototypes built and tested by the Air Force have demonstrated the feasibility and payoff of this design concept.
    • Lowest Cost Alternative to Auto-Tracking Using GPS-TRAK, Augustin-Sullivan Distribution, & Single Axis Antenna Techniques

      Augustin, Eugene P.; Dunn, Daniel S.; Sullivan, Arthur; Technical Systems Associates, inc. (International Foundation for Telemetering, 1993-10)
      The first telemetry tracking system was desired in 1959 for the space program. Cost was of little concern. The tracking technique used was 3 channel monopulse which is still today, after all these years, the optimum in performance for any type of tracking requirement. Telemetry tracking really got off the ground in the early 1970's with the move from P-Band to S-Band for telemetry. In the design of early tracking systems, performance was on the top of the list, and cost was on the bottom of the list in establishing the design criteria. By the beginning of the 1980's cost was approaching performance in importance. Today, with the demise of the cold war and a considerable reduction in global threats coupled with the state of the world economy, cost has now reached the top of the list. The cost of a telemetry tracking system can be reduced by more than a factor of two by going to a single axis tracking technique. The lowest cost single axis approach heretofore has been the use of a cosecant squared (CSC²) distribution. To improve the efficiency of a single axis system and increase the overhead coverage capability, the use of a dual beam antenna has been widely used as another type of single axis approach. The dual beam technique involves additional costs since two tracking antennas are required. Except for satellite tracking, almost all telemetry tracking is performed at low elevation angles and, like it or not, multipath is there. The multipath fade varies from a few dB, to over 20 dB depending upon the reflecting terrain. Most general purpose systems should be designed for at least a 10 dB multipath fade. For all telemetry tracking applications, the multipath effect is completely negligible at elevation angles greater than 10 degrees. The Augustin-Sullivan Distribution, in effect, fades away the multipath margin as the multipath effect decreases. Because of the multipath phenomenon, an antenna beam should not be shaped at the one dB point as is the case with a CSC² distribution, but only needs to be shaped from somewhere between the 15 - 20 dB level based on the mission requirements. This involves a gain reduction from a pencil beam on the order of 1/2 dB or less, rather than the 3 dB reduction associated with the CSC² distribution. The Augustin-Sullivan distribution does not start shaping the beam until shaping is retired, and shapes the beam for constant altitude coverage from the horizon to zenith. For the first time, coverage is provided from the peak of the beam to directly overhead with a single antenna and a single axis rotator. When GPS information is available from the tracked vehicle, the Augustin-Sullivan distribution, with a single axis rotator and using the GPS-TRAK technique, results in the lowest possible cost alternate to autotracking.
    • FM, PM and NPR Calculations

      Gallupe, Gary; APCOM, Inc. (International Foundation for Telemetering, 1993-10)
      System performance can be ascertained via a number of parameters; one of which is Signal-to-Noise ratio (SNR). SNR is the ratio of the value of the signal to the value of the noise. It is generally expressed in decibels and usually a function of the system bandwidth. Another measure of performance is the Noise-Power ratio (NPR). NPR is the ratio of the noise level within a specific measurement channel when noise is applied to all channels, to the level that is measured within the specific channel with noise applied to all of the channels but not the specific channel.
    • Mission-Independent Telemetry Processing Software for PCs

      Miller, Richard J.; Micro SciTech Ltd. (International Foundation for Telemetering, 1993-10)
      Until the early 80's, telemetry processing systems were commonly run on mainframe or mini computers running proprietary operating systems and software with limited portability. The advent of the 'low-cost' workstation reduced the hardware cost but the software still remained relatively expensive and relatively mission specific. The workstation itself, although comparatively cheap, was not, and is still not, an everyday piece of computing hardware Telemetry Processing software has been developed by Micro SciTech to meet both low-cost hardware requirements and mission independence. It runs on networked IBM PC compatible computers and can be re-configured and used for many different missions and experiments without the need for extensive software rewrites.
    • Implementation of a Low Cost Commercial-Off-the-Shelf Commanding System

      Grich, Richard J., Jr.; Bourassa, Chris R.; Storm Integration, Inc. (International Foundation for Telemetering, 1993-10)
      Traditional satellite and launch control systems have consisted of custom solutions requiring significant development and maintenance costs. These systems have typically been designed to support specific program requirements and are expensive to modify and augment after delivery. Over the past five years, technical advances have resulted in Commercial-Off-The-Shelf (COTS) products which greatly reduce the complete life cycle costs associated with satellite and launch control system procurements. These advances, however, have been restricted to specific functional areas of the satellite and launch control system - most notably, telemetry processing and simulation. Until recently, technological advances in the development of COTS products which support functional areas like commanding and mission planning have lagged behind. This paper describes the development and application of a COTS product which provides a highly advanced commanding capability that is tightly integrated with the processing of telemetry data. This closed loop telemetry and commanding system forms the basis of a satellite or launch control system at a fraction of the cost normally associated with systems of this kind.
    • The Phillips Laboratory's Mobile Ground Telemetry Station (MGTS) Configuration and Operations

      Flint, Keith D.; Mathis, Gregory P.; Cronauer, Tom G.; Philips Laboratory (International Foundation for Telemetering, 1993-10)
      In support of the various programs that the Phillips Laboratory's Space Experiments Directorate is conducting for the Ballistic Missile Defense Organization (BMDO), the Range Operations Division is developing a mobile telemetry processing system as part of the Mobile Ground Telemetry Station (MGTS) program. The MGTS program's goals are to develop a mission-dedicated telemetry system to supplement current test range capabilities by receiving, processing and recording multiple data streams, sometimes exceeding 10 Mbps. The system will support airborne and suborbital vehicles as well as customized satellite downlinks designed for spacecraft bus State-of-Health monitoring and sensor payload observations. Autonomy and off-road capabilities are also important factors since some of the operations envisioned require deployment to remote field locations where no telemetry processing capabilities currently exist to support the unique data handling requirements. The Phillips Laboratory has completed, with support from Wyle Laboratories and Systems Engineering and Management Company (SEMCO), a "proof-of-concept" mobile telemetry processing system referred to as MGTS #2. Demonstration of the system has been accomplished with the successful deployment and operational support provided to both BMDO's Lightweight Exo-Atmospheric Projectile (LEAP) sub-orbital missions and Miniature Sensor Technology Integration (MSTI) satellite program. MGTS #2 has deployed and is scheduled for further deployment to various operating sites including: White Sands Missile Range (WSMR), NM; Air Force Flight Test Center (AFFTC), Edwards AFB, CA; Vandenberg AFB, CA; and NASA's Wallops Island Flight Facility, VA. While deployed MGTS #2 processes, records and rapidly distributes the critical mission telemetry data conforming to both IRIG and SGLS standards. This paper will describe the evolution of the MGTS program, current hardware configurations and the various mission scenarios that have been supported by the MGTS team.
    • Micro-Track Digital Cassette Recording

      Kayes, Edwin; Penny & Giles Data System (International Foundation for Telemetering, 1993-10)
      The increasing availability of powerful yet relatively inexpensive data acquisition and processing techniques has precipitated a radical reappraisal of the methods used to capture, manipulate and store data of all kinds. Some of the recently introduced recording systems can be used both for fast data capture and for high capacity archival/back-up applications - effectively bridging a long-standing divide between these two formerly diverse aspects of data recording and processing. This paper offers a brief overview of a new technology known as micro-track recording, and suggests ways in which system designers and integrators may take full advantage of its important new facilities and features.
    • TDRSS Link Budget Design Table

      Minnix, Timothy; Horan, Stephen; New Mexico State University (International Foundation for Telemetering, 1993-10)
      The Consultative Committee for Space Data Systems (CCSDS) has issued a Recommendation CCSDS 401.0-B for Radio Frequency and Modulation Systems to be used in Earth stations and spacecraft. Part of this Recommendation is a standardized design tool for link budget computations. This design tool is intended to assist spacecraft designers in preparing the power and performance designs of their spacecraft for communicating with existing standard ground stations. The present CCSDS Recommendation addresses a link design typical for that found with the Deep Space Network (DSN). DSN link analyses use a large subset of link-specific parameters not of any particular use if the space data link passes through the Tracking and Data Relay Satellite System (TDRSS). The link architecture also differs in that the TDRSS parameter set needs to include an extra link through the satellite (two-hop) link versus a DSN-type link which is single-hop. Conversely, the treatment of ranging, PN coding requirements, and TDRSS acquisition and data group formalities are either not of the same format or not present at all on the DSN-type links. The baseline CCSDS 401 design tool is a Microsoft Excel spreadsheet that can run on an IBM PC or compatible computer. This baseline spreadsheet has been modified to account for the differences between baseline CCSDS model and TDRSS link operations. The paper will discuss the modifications made to the spreadsheet for the TDRSS system details. We will also present example usages of the spreadsheet.
    • Magellan Recorder Data Recovery Algorithms

      Scott, Chuck; Nussbaum, Howard; Shaffer, Scott; California Institute of Technology; Hughes Aircraft (International Foundation for Telemetering, 1993-10)
      This paper describes algorithms implemented by the Magellan High Rate Processor to recover radar data corrupted by the failure of an onboard tape recorder that dropped bits. For data with error correction coding, an algorithm was developed that decodes data in the presence of bit errors and missing bits. For the SAR data, the algorithm takes advantage of properties in SAR data to locate corrupted bits and reduce there effects on downstream processing. The algorithms rely on communication approaches, including an efficient tree search and the Viterbi algorithm to maintain the required throughput rate.