Sullivan, Arthur; Electro Magnetic Processes, Inc. (International Foundation for Telemetering, 1989-11)
      About a half of a century ago, born of necessity created by World War II, automatic tracking techniques were developed. The first successful tracking system to go in production was the SCR 584 Radar developed for the U.S. Army Signal Corps in about 1942. Early tracking systems consisted of an antenna, a gimbal to support and position the antenna beam to track the target, a servo to control the movement of the gimbal, a control system for the operator to control the tracking, a transmitter to illuminate the target, and a receiver to receive the reflected signal from which the tracking error signal was extracted and sent to the servo. It is interesting to note that this description also fits today’s tracking systems. True -- telemetry signal tracking is passive and does not require the transmitter and true -some of the modern antennas do not require a gimballed support but the basic elements of the tracking system are still the same. However, over the last 50 years, there have been considerable changes and improvements in available materials, components, methods and technology. The scope of this paper is limited to the antenna and its progress in this changing technology. Presented herein is a brief history of tracking systems and discussion of the various tracking antennas developed over the years as well as the present tracking technology and that of the future.

      Qiu-Cheng, Xie; Zhong-Kui, Lei; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1989-11)
      In this paper, twelve optimum group synchronization codes (n=31 to 42) for PCM telemetry systems are presented. They are the newest achievements up to now.
    • A High Speed Miniature Pulse Code Modulation System

      Baughman, James E.; Gulton Data Systems (International Foundation for Telemetering, 1989-11)
      Increasing speed and complexity of guidance and target acquisition systems being developed for SDI missile interceptors mandate new performance standards for today's airborne telemetry systems. High bandwidth video data merged with a myriad of high sample rate analog and digital channels have pushed bit rates to 10 MBPS (Mega Bits Per Second) and beyond. These bit rates which are an order of magnitude beyond most telemetry systems in use today, result in the need for a new architecture which facilitates data transfer at these higher rates.
    • RTDAP: Real-Time Data Acquisition, Processing and Display System

      Dahan, Michael; Instrumentation and Telemetry Systems (International Foundation for Telemetering, 1989-11)
      This paper describes a data acquisition, processing and display system which is suitable for various telemetry applications. The system can be connected either to a PCM encoder or to a telemetry decommutator through a built-in interface and can directly address any channel from the PCM stream for processing. Its compact size and simplicity allow it to be used in the flight line as a test console, in mobile stations as the main data processing system, or on-board test civil aircrafts for in-flight monitoring and data processing.

      Strock, O.J. (Jud); Fairchild Weston Systems, Inc. (International Foundation for Telemetering, 1989-11)
      For as long as telemetry has been used in scientific research, users have asked for transmission of more data points at higher data frequencies. Now, the increased complexity of vehicles under test and the presence of data from one or several computer systems on a vehicle has further increased the rate and format complexity of a typical telemetry data stream. To accommodate higher data rates and increased complexity, many telemetry ground stations use distributed processing techniques, typically employing a hardware preprocessor, a host computer, and one or more intelligent display stations. While this distribution of power potentially enhances data throughput rates, it imposes new demands on data distribution networks within the processing area, and the full potential of the processors cannot be met until these demands have been met. This paper looks first at system architecture of the typical ground station, and how this architecture and telemetry data rate capability have progressed during the past 20 years. Then it looks at the data distribution requirement in a modern telemetry ground station, explores possible solutions to improve throughput rates, and describes a set of solutions for typical system applications in the next few years.
    • From Transducer to Display in a Workstation Environment: A Real Time Data Acquisition System

      Wargo, William D.; Watt, Gill; Metraplex Corporation (International Foundation for Telemetering, 1989-11)
      This paper will address the application of an end-to-end programmable PCM telemetry system featuring a modular, programmable data acquisition and encoding system, and a data analysis work station using an IBM PC compatible computer.
    • High Speed VLSI Systems for NASA's Telemetry Return Link Processor

      Hand, Sarah L.; Salichs, Luis G.; Steedman, John K.; NASA, Goddard Space Flight Center (International Foundation for Telemetering, 1989-11)
      In the upcoming Space Station Freedom (SSF) era, NASA will require many new data systems capable of performing basic data handling functions such as Frame Synchronization, Frame Error Detection & Correction, and Multiplexing/Demultiplexing at rates in the hundreds of Megabits per second (Mbps) range. The Data Interface Facility (DIF) is a key element in NASA's advanced communications systems. The DIF will support communications between the space elements and multiple ground facilities. This paper will describe the architecture of the DIF and its core element, the Return Link Processor (RLP). Current activities to prototype some of the primary functions of the RLP will be presented. Finally, the paper will show how the prototype elements could be integrated into a full performance DIF RLP.
    • Development of Real-Time Software Environments for NASA's Modern Telemetry Systems

      Horner, Ward; Sabia, Steve; NASA, Goddard Space Flight Center (International Foundation for Telemetering, 1989-11)
      The design and development of generic, low cost, high performance telemetry components and systems require the optimum integration of custom and standard hardware elements with a number of real-time software elements. To maintain maximum flexibility and performance for Goddard Space Flight Center's VLSI telemetry system elements, two special real-time system environments were developed. The Base System Environment (BaSE) supports generic system integration while the Modular Environment for Data Systems (MEDS) supports application specific development. Architecturally, the BaSE resides just on top of a commercial real-time system kernel while the MEDS resides just on top of the BaSE. The BaSE provides for the basic porting of various manufacturer's cards and insures seamless integration of these cards into the generic telemetry system. With this environment, developers are assured a rich selection of available commercial components to meet their particular application. The MEDS provides the designer with a set of tested generic library functions that can be employed to speed up the development of application specific real-time code. This paper describes the philosophy behind the development of these two environments and the characteristics which define their performance and role in a final VLSI telemetry system.
    • Distributed Microprocessing of PCM Telemetry Provides Unlimited Real Time Analysts Displays

      Johnson, James F.; The Aerospace Corporation (International Foundation for Telemetering, 1989-11)
      Invariably, during the launch of large scale spacecraft, there is a need to provide large numbers of analysts with real time telemetry displays. This is especially true of "one-of-a-kind" or "first-of-a-series" spacecraft. These analysts have a wide range of needs and are specialists in many diverse disciplines. The problem is how to divide up a high speed telemetry stream in such a way that each analyst has access to the measurements of interest. Many large scale systems have been built to do this, but are often limited as to the number of displays that can be supported, and are easily swamped by data requests. This paper presents a microcomputer architecture which supports an unlimited number of individual displays and provides each analyst with access to all measurements from which data of interest may be chosen at will, with no affect on system throughput. In addition, the system is inexpensive, very flexible, and relatively easy to implement.

      Svensson, Ake; Maoz, Michael; Saab Missiles AB; RAFAEL; Aydin Vector Division (International Foundation for Telemetering, 1989-11)
      Aydin Vector Division has developed and manufactured an airborne, high shock, wideband FM/FM telemetry system for Saab Missiles AB in Sweden. This system was presented in the ITC Proceedings of 1988, Volume XXIV, pp 71-84 (Ref [1]). Three such systems were supplied. Saab Missiles AB also awarded Aydin Vector Division with an additional order for a larger number of high shock, computer based, specially designed, miniature PCM/FM airborne telemetry systems. These systems were developed, manufactured and supplied to Saab Missiles AB, and have been extensively and successfully used in the Swedish program. The PCM/FM telemetry package described in this paper was used for the system testing and the firing trials program of a mortar projectile, where the measurement requirements included micro processor interfaces, as well as a high amount of analog and bi-level data channels. The paper covers the specifications of the PCM/FM system mentioned above, the concept that was used to meet these specifications, the system’s mechanical and electrical design, the packaging technique and some of the test results.
    • Subminiature Telemetry Systems For Submunitions

      Renken, G.; Ferguson, D.; Havey, G.; Kriz, J.; Olson, R.; Honeywell Sysytems and Research Center (International Foundation for Telemetering, 1989-11)
      The increased sophistication and reduced size of the emerging generation of ‘smart’ submunitions has generated a requirement for subminiature telemetry systems for use in test and evaluation. The Army’s SADARM and the Air Force’s Sensor Fuzed Weapon (SFW) are typical of smart submunitions with multiple sensors, VHSIC signal processing, large warheads, and complex deployment sequences. Reported here is the SADARM Telemetry Module, designed and developed by Honeywell to support the SADARM Program. The SADARM Telemetry Module applies MMIC and VLSI technology to provide sophisticated telemetry operation with a physically small, (2 in ) package, in a harsh operating environment. The 3 SADARM Telemetry Module senses 17 channels of digital and analog data, digitizes the analog data, multiplexes and PCM formats the data stream and transmits it via an IRIG compatible MMIC transmitter. This SADARM Telemetry Module was used to collect in-flight performance data at the SADARM Congressional Tests in February, 1989. Submunitions have evolved into very complex systems. Submunition development support testing has also become increasingly complicated. Onboard flight recorders are not feasible for live submunition tests because destruction of the submunition after the test precludes recovery of the recorded data. Telemetry provides the necessary test and measurement support required for efficient, cost effective, submunition development. The application of conventional telemetry for this type of submunition instrumentation has also become more difficult as the submunitions have become smaller in size and have more complex deployment sequences to evaluate. In addition, subminiature telemetry provides a practical, cost effective means to support field testing and development efforts in multiple munition weapon systems. In fact, subminiature telemetry offers the most practical instrumentation approach to evaluate the in-flight performance of several munitions dropped simultaneously. The SADARM Telemetry Module, discussed in this paper, incorporated these subminiature telemetry performance requirements into a practical, cost effective instrumentation package for SADARM development support.

      Baughman, James E.; Gulton Data Systems (International Foundation for Telemetering, 1989-11)
      Increasing speed and complexity of guidance and target acquisition systems being developed for SDI missile interceptors mandate new performance standards for today’s airborne telemetry systems. High bandwidth video data merged with a myriad of high sample rate analog and digital channels have pushed bit rates to 10 MBPS (Mega Bits Per Second) and beyond. These bit rates which are an order of magnitude beyond most telemetry systems in use today, result in the need for a new architecture which facilitates data transfer at these higher rates.

      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.

      Dahan, Michael; Instrumentation and Telemetry Systems (International Foundation for Telemetering, 1989-11)
      This paper presents a 1553 Muxbus Interface which can acquire data, selectively, from up to 3 redundant busses and process it for different airborne or ground test applications. The Interface is built using up todate electronic technology in order to overcome the problems encountered in 1553 protocol decoding and to insure proper data integrity.
    • 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.

      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.
    • The Rotor-Signal-Module of MFI90

      Holland, Rainer; DLR Institut für Flugmechanik, Braunschweig, West Germany (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.

      Malatesta, William A.; Veda Incorporated (International Foundation for Telemetering, 1989-11)
      The number and types of processes carried out on telemetered data in real time have increased in direct proportion to the available processing speeds. Operations following decommutation in the data pipeline are often referred to generically as Engineering Units Processing (EUP). Examples of the types of functions typically performed by an EUP are data compression, polynomial conversion, and with the advent of message data, desyllabification. Real-time telemetry processing, such as EUP, has traditionally been done on bitslice processors, primarily because they possessed the speed required to maintain pace with the relatively high data rates. As data rates continue to increase, the need for bitslice processors with even higher processing speeds would seem to be even more pressing. However, in recent years RISC (Reduced Instruction Set Computer) based microprocessors have been developed that approach bit-slice processing rates and possess certain advantages. The advantages of a RISC based approach to real-time telemetry processing include ease of programming, shorter design and implementation cycles, and a direct path to speed increases as silicon processing technology advances. In addition, the streaming nature of the data to be operated on, and the EUP requirements generate a multi-branched program structure creating the potential for a high degree of optimization within a pipelined processor architecture. While most RISC applications are currently programmed in assembly language to take full advantage of the hardware, it is expected that improvements in optimizing compilers in the future will further enhance the position of RISC with respect to bit-slice processing.

      ANDERSEN, R.; WENDEL, W.; DATATAPE INCORPORATED (International Foundation for Telemetering, 1989-11)
      Multiple channel magnetic tape recording is often used for signal analysis of intelligence and telemetry data. To insure accuracy of the reproduced data, these systems require frequent calibration and alignment. As the number of tracks on these systems has increased, this task has become more time-consuming. Even with a well-trained technician, this task can take several hours at a minimum. To alleviate this problem, we developed a system for performing this calibration automatically. The implementation utilizes a Fast-Fourier-Transform technique to analyze the output of a pre-recorded signal on tape. The desired response, most frequently defined by IRIG Standards, is stored in a look-up table in the machine. The actual response is compared to that desired, and, under micro-processor control, adjustment made in the signal channel until an acceptable response is achieved. A unique photo-resistor technique is used in the signal path to control such parameters as gain and phase. A description of the hardware system will be given, as well as a description of the algorithms utilized for implementation.
    • Trends in Recording Capabilities For The ‘90’s’

      Hoover, J.H.; GE Aerospace (International Foundation for Telemetering, 1989-11)
      As sensor bandwidths increase and the amount of information gathered increases, higher capacity storage devices will be required as well as increased capture/transmission/reproduce data rates. Both collection/capture sites (with more sensors and wider bandwidths) and link receive/distribution sites will need to be upgraded to accommodate high transmission rates, provide rate matching for capture/dissemination/processing and provide higher capacity storage. These trends and recorder solutions are forecast as natural evolution of the state-ofthe-art. Extended performance (high data rate/high capacity) tape recorders will be discussed as applicable to satelliteto-ground communication, space platform experimental data gathering, reconnaissance, ASW sonar, radar and data processing systems.