Mackall, Dale A.; Sakahara, Robert; Kremer, Steven E.; National Aeronautics and Space Administration; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Development of an extended test range, with range instrumentation providing continuous vehicle communications, is required to flight-test the X-33, a scaled version of a reusable launch vehicle. The extended test range provides vehicle communications coverage from California to landing at Montana or Utah. This paper provides an overview of the approaches used to meet X-33 program requirements, including using multiple ground stations, and methods to reduce problems caused by reentry plasma radio frequency blackout. The advances used to develop the extended test range show other hypersonic and access-to-space programs can benefit from the development of the extended test range.

      Barton, Randal L.; New Mexico State University (International Foundation for Telemetering, 1998-10)
      The Near Earth Asteroid Prospector (NEAP) has a scheduled launch date between mid- 1999 and mid-2000, and will encounter a yet to be determined near Earth asteroid (1.1 - 2.2 AU distance from Earth) some ten months later [2]. The purpose of this mission is not only to collect valuable scientific and geological data, but to also determine the value of the asteroid’s materials for possible mining and exploitation [2], [3]. The purpose of this paper is to detail frequency allocation issues and to determine possible return (space to Earth) data rates associated with deep space communications with the NEAP spacecraft.
    • International Telemetering Conference Proceedings, Volume 34 (1998)

      Unknown author (International Foundation for Telemetering, 1998-10)

      Skelley, Daniel S.; Jones, Sidney R., Jr.; Naval Air Warfare Center Aircraft Division (International Foundation for Telemetering, 1998-10)
      The purpose of this paper is to present a broad view of the impact of network architectures on future data acquisition systems. The major advantages and challenges associated with the use of network architectures are rooted in the packetized structure of the data. Many of the issues raised are subtle and complex. It is not the intent of this paper to give these issues the thorough academic and technical analysis they deserve. It is the hope of the authors this paper will generate awareness and discussion on these issues.
    • Range Communications System Using Asynchronous Transfer Mode (ATM)

      Eslinger, Brian; McCombe, Joleen; TYBRIN Corp.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      As aircraft become more complex and require more resources over larger areas, the challenge of the test ranges is to provide economical solutions to move telemetry data from the test article to the data processing facility. Edwards AFB is in the process of upgrading the ground transmission facilities to transport data including telemetry using Asynchronous Transfer Mode (ATM). This paper documents the challenge of supporting telemetry over ATM, different approaches that are available, the benefits of using ATM, and discussion of candidate hardware options. The effort at Edwards include the linking of the major range facilities over a fiber optic backbone and links to other major test ranges in the Southwest Range Complex via microwave. The fiber optic backbone is expected to be OC-12c (622 Mbps) ATM supporting new capabilities as well as all of the legacy systems. The backbone system will be designed so that migration to OC-48 is possible without service disruption. The microwave links are multiple DS-3 capable. Some of these DS-3s may support legacy systems, but the ability to link ranges using ATM is expected simultaneously.

      Shigemoto, Fred; Wei, Mei; Somes, Austin; Ng, Sunny; NASA; Sterling Software (International Foundation for Telemetering, 1998-10)
      FAA is currently evaluating DGPS based CAT III Landing Systems for use as the next generation commercial aviation landing system standard. Any technique to validate such a DGPS based system must have at least equivalent accuracy. A laser position tracking system coupled with a high performance real-time computational capability was developed providing real-time analysis of performance. This real-time performance measurement system was key in enabling the quick completion of a large number of test approach and landings needed to achieve statistically accurate results.
    • Automatic Gain Control and Doppler Motion Models in LabVIEW

      Laird, Daniel T.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      A simplex or ‘passive’ continuous wave and monopulse seeker tracks specific attributes of a target’s radio frequency (RF) radar return in some coordinate frame. In particular, a return carries dynamic information in amplitude (ω) and frequency (ω) at some point in azimuth (r,θ) and elevation (r,θ) planes. A passive seeker requires an illuminator beam, I(ω,φ,θ), and may require a frequency modulation on the illuminator. To model a simplex target return, we have based the dynamics on a point source radar cross section (RCS) along a line of sight (LoS) radial. The Az and El angles are equivalent to antenna placement, the attenuation and frequency dynamics are modeled in commercial off-the-shelf (COTS) software.
    • Accuracy of Computer Simulations that use Common Pseudo-random Number Generators

      Dusitsin, Krid; Kosbar, Kurt; University of Missouri – Rolla (International Foundation for Telemetering, 1998-10)
      In computer simulations of communication systems, linear congruential generators and shift registers are typically used to model noise and data sources. These generators are often assumed to be close to ideal (i.e. delta correlated), and an insignificant source of error in the simulation results. The samples generated by these algorithms have non-ideal autocorrelation functions, which may cause a non-uniform distribution in the data or noise signals. This error may cause the simulation bit-error-rate (BER) to be artificially high or low. In this paper, the problem is described through the use of confidence intervals. Tests are performed on several pseudo-random generators to access which ones are acceptable for computer simulation.

      Monica, G. Della; Tonello, E.; ALCATEL (International Foundation for Telemetering, 1998-10)
      Presentation of Alcatel Espace last studies and developments regarding TT&C receiver Products for satellite. This document lays on 3 parts: · a technical point of view showing digital demodulation principles used (base band recovery, analytical head, PM or FM demodulation) and their related offered possibilities(digital controlling loop, lock status detection, jammer detection,....) · a technology/design description · a synthesis showing performance and results

      Weis, R. Stephen; Bachim, Brent L.; Texas Christian University (International Foundation for Telemetering, 1998-10)
      The design and testing of an optical fiber telemetry link for use in rugged environments is described. Several potential applications for this cost effective telemetry link built from readily available components are given. The results of testing the simple telemetry link for vibrations up to 20g and temperatures up to 150° C are reported.

      Colangelo, Ronald; Simulation, Training and Instrumentation Command (International Foundation for Telemetering, 1998-10)
      There is an acquisition management challenge to a program which has a limited market. One approach which can improve competition is the utilization of commercial technology. This utilization helps reduce unit cost and system obsolescence. The Hardened Subminiature Telemetry and Sensor System (HSTSS) has experienced the affects of a limited market and the need to utilize commercial technology. HSTSS plans to use partnering because the expertise is spread across the industry, and technology integration is required to fabricate an instrumentation system that would meet tri-service test requirements. There are many challenges facing the Program Manager; which create high program risk when proper acquisition procedures are not followed. HSTSS is this type of project. This paper will essentially discuss the acquisition strategy as it has evolved as well as the technical strategy. These strategies have been influenced by Government acquisition streamlining , available commercial technology and the programs limited production requirements. This is what the Government’s Project Managers are facing in these times of shrinking budgets and downsizing. The importance of the services working together, and sharing funds and technology to accomplish more with less is discussed in this paper. It is essential that government and industry work together as partners to reach the program’s goals. This paper proposes a program strategy based on our experience as to what is needed to incorporate partnering and commercial technology to successfully complete your program.

      Tonello, E.; Monica, G. Della; ALCATEL (International Foundation for Telemetering, 1998-10)
      Presentation for ITC 98 of Alcatel Espace last studies and developments regarding TTC Products This document lays on 3 parts: · a technical point of view · a technology/design description · a synthesis showing main performance and results
    • Application of IP Multicasting to the NASA Communications Command and Telemetry Ground Network

      Spinolo, M. Chris; National Aeronautics and Space Administration (International Foundation for Telemetering, 1998-10)
      The NASA Communications (Nascom) Division has been directed to deploy Internet Protocol (IP) based technology for the ground segments of all present and future spaceflight telemetry networks. The Nascom network supports all NASA spaceflight telemetry, command and status requirements, from sounding rockets and balloons to the Hubble Space Telescope and the Space Shuttle. This paper discusses the challenges of transitioning a 35 year old, custom engineered, worldwide legacy telemetry network to IP, and the resulting, new NASA IP Operational Network for ground transport of spacecraft telemetry and command.
    • TCP/IP Remote Control of a Ground Station

      Massey, Dale P.; Universal Space Network, Inc. (International Foundation for Telemetering, 1998-10)
      Satellite tracking ground stations are under continuous pressure to automate. Autonomy is generally the desired goal, but if the ground stations are in a Commercial Ground Network(CGN) setup to support many missions simultaneously, remote control of such stations is of much more importance. The proliferation of Low Earth Orbiting (LEO) science, earth resources and eventually global communications satellites either in orbit or planned, requires a much lower cost methodology for ground support. A CGN of TCP/IP remotely controlled ground stations lowers much of the manpower that was historically required to operate such stations. This paper will cover the remote control aspects needed for a satellite ground tracking station and offer a unique remote control topology utilizing TCP/IP.
    • High Rate Digital Demodulator ASIC

      Ghuman, Parminder; Sheikh, Salman; Koubek, Steve; Hoy, Scott; Gray, Andrew; National Aeronautics and Space Administration; Lockheed Martin Space Mission Systems & Services; SGT Inc. (International Foundation for Telemetering, 1998-10)
      The architecture of the High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA’s Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an overview of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.

      Weitzman, Jonathan M; GDP Space Systems (International Foundation for Telemetering, 1998-10)
      A Phase Modulator combining digital techniques with non-traditional analog circuitry can minimize the shortcomings of a traditional (purely analog) Phase Modulator. These shortcomings are: nonlinear response from input modulating signal to output modulated signal; parameters (frequency and modulation index) that are difficult to set; and the need for complex filters. The design approach discussed in this paper uses a combination of Direct Digital Synthesis (DDS) and analog devices operating in their linear range to generate a Phase Modulated RF (140 MHz) signal. A Numerically Controlled Oscillator (NCO) digitally generates the first IF yielding a very accurate, repeatable and linear signal with easily adjustable parameters such as frequency and modulation index. Linear multipliers (instead of saturated diode mixers or step recovery diodes) are used for up-conversion to RF. Using linear multipliers eases the filtering requirements due to the significantly reduced harmonics and IM (Inter-Modulation) terms. The resulting RF signal is easily translated to higher frequency bands such as L, S, C, X or K.

      DiLemmo, Marc C.; Aydin Telemetry (International Foundation for Telemetering, 1998-10)
      This paper illustrates a device driver implementation used to support a PC compatible telemetry device. Device requirements included operation on Windows NT 4.0, Windows 95, Windows NT 5.0 and Windows 98 platforms. A single device driver was not possible due to the differences between driver requirements on the various operating systems. The Windows Driver Model (WDM) was considered for NT 5.0 and Win98, however, NT 4.0 and Win95 does not support the WDM. To minimize software development and support efforts, it was clear that an architecture compatible to both WDM, NT 4.0 and Windows 95 needed to be developed. The resulting layered device driver architecture provides a common upper interface and uses a register based model to describe the hardware at the lower interface. The common upper interface is compatible with all of the target operating systems and presents a consistent Applications Programming Interface (API) for the telemetry application developer. The lower interface is specific for each platform but contains minimal device specific functionality. A simple register I/O driver is easily implemented using all of the target operating systems. The layered architecture and register based interface to the hardware results in a multiple operating system code set which differs only at the lowest layer.

      Sharma, Ashley; National Aeronautics and Space Administration (International Foundation for Telemetering, 1998-10)
      In support of the X-33 single-stage-to-orbit program, NASA Dryden Flight Research Center was selected to provide continuous range communications of the X-33 vehicle from launch at Edwards Air Force Base, California, through landing at Malmstrom Air Force Base, Montana, or at Michael Army Air Field, Utah. An extensive real-time range simulation capability is being developed to ensure successful communications with the autonomous X-33 vehicle. This paper provides an overview of the various levels of simulation, integration, and test being developed to support the X-33 extended range subsystems. These subsystems include the flight termination system, L-band command uplink subsystem, and S-band telemetry downlink subsystem.

      Ng, Sunny; Wei, Mei Y.; Somes, Austin; Aoyagi, Mich; Leung, Joe; National Aeronautics and Space Administration; Recom Technologies (International Foundation for Telemetering, 1998-10)
      This paper describes a distributed network client-server system developed for researchers to perform real-time or near-real-time analyses on ensembles of telemetry data previously done in post-flight. The client-server software approach provides extensible computing and real-time access to data at multiple remote client sites. Researchers at remote sites can share similar information as those at the test site. The system has been used successfully in numerous commercial, academic and NASA wide aircraft flight testing.

      DeBenedetto, Louis J.; Myriad Logic, Inc. (International Foundation for Telemetering, 1998-10)
      Since becoming an ANSI standard in 1994, Fibre Channel has matured into a high-speed reliable data communication solution. Fibre Channel uses point-to-point, arbitrated loop, or switched topologies, to provide a wide range of options for data storage and highspeed data transfer applications. Unlike Gigabit Ethernet, Fibre Channel supports protocols such as HIPPI-FP, SCSI and IPI, allowing for greater flexibility when designing systems. However, the wide range of options supported in the Fibre Channel standard can be the source of misunderstanding and incompatibility. This paper intends to clear up some of the misconceptions about Fibre Channel by presenting the current standard and discussing how Fibre Channel can be used in data acquisition systems. Since these systems often require extremely high throughput for routing data, as well as high speed data storage to long term media, solutions are not often cut and dry. This paper will give examples of how using different layers of the Fibre Channel protocol will meet the needs of today’s data acquisition requirements. It provides a brief overview of Fibre Channel technology and identifies the different types of Fibre Channel products available. It provides examples of how commercial-off-the-shelf (COTS) products can be used to build data acquisition and storage systems requiring throughputs of up to 90 Mbytes per second on a single fiber. Additionally, it shows how multiple fibers can be used to achieve much higher data rates.