• International Telemetering Conference Proceedings, Volume 34 (1998)

      International Foundation for Telemetering, 1998-10

      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.

      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.
    • Selling Telemetry Data Over the Internet Using SET

      Kalibjian, Jeffrey R.; CounterSign Software, Inc. (International Foundation for Telemetering, 1998-10)
      Over the past two years the design and implementation of secure Internet based data sharing tools which could enable geographically remote contractor teams to access flight and test telemetry data securely over the Internet were presented [1] [2]. Key technologies facilitating these capabilities were the Hypertext Transfer (HTTP) protocol , the Secure Sockets Layer (SSL) protocol, and the Secure Multipurpose Internet Mail Extension (S/MIME) specification . This year we discuss utilizing the Secure Electronic Transaction (SET) specification in tandem with HTTP, SSL, and S/MIME to deploy a system for securely selling telemetry data over the Internet.
    • 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.

      Leung, Joseph; Aoyagi, Michio; Billings, Donald; Hoy, Herbert; Lin, Mei; Shigemoto, Fred; NASA (International Foundation for Telemetering, 1998-10)
      As renewal interest in building vehicles based on hypersonic technologies begin to emerge again, test ranges anticipating in supporting flight research of these vehicles will face a set of engineering problems. Most fundamentals of these will be to track and gather error free telemetry from the vehicles in flight. The first series of vehicles will likely be reduced-scale models that restrict the locations and geometric shapes of the telemetry antennas. High kinetic heating will further limit antenna design and construction. Consequently, antennas radiation patterns will be sub-optimal, showing lower gains and detrimental nulls. A mobile system designed to address the technical issues above will be described. The use of antenna arrays, spatial diversity and a hybrid tracking system using optical and electronic techniques to obtain error free telemetry in the present of multipath will be presented. System tests results will also be presented.

      Scofield, Don; Powell, Dave; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 1998-10)
      The Joint Advanced Missile Instrumentation (JAMI) Program, a multi-year CTEIP effort, will develop an integrated instrumentation package for tri-Service small missile test and training applications. JAMI will provide telemetry, time-space-position information (TSPI), flight termination and end-game vector scoring in a low-cost, modular package that will allow world-wide test and training, thereby eliminating, in most cases, the need for range-specific (or multi-system) facilities. JAMI will incorporate GPS-based technology as the TSPI and vector scoring engine, as well as state-of-the-art telemetry. JAMI will also address the feasibility of a solid state programmable safe-and-arm device. The effort will include a Test Technology Development and Demonstration (TTD&D) risk reduction phase which will validate tri-service requirements, provide a technology demonstration, and assess the applicability of advanced antenna technology. This paper discusses the progress of the program during the TTD&D phase including preliminary testing of GPS receivers and conformal GPS antennas.
    • 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.

      Cylc, Linda; Aydin Telemetry (International Foundation for Telemetering, 1998-10)
      PSK demodulators have been an integral part of the signal recovery process for decades. Unless a person has designed a demodulator, how much can a person know or understand about its operation? Instruction on how to set up a demodulator’s parameters to acquire a signal is found in a manual. An explanation of why parameters are set a certain way to handle particular input signal characteristics is often not provided in a manual. This paper is designed to be a tool to aid engineers, technicians, and operators who utilize demodulators. Its purpose is to relay the functionality of a demodulator to a user so that he or she can take advantage of its control parameters and status feedback. Knowing the reasons why a demodulator is set to certain parameters may greatly reduce confusion when a system is not working properly. On site troubleshooting may be accomplished without the need to call the manufacturer of the product. Another advantage of understanding the operation will be recognized when interfacing with the manufacturer. A person will be able to relay the information to a design engineer more easily, and will understand more of the engineer’s feedback on the potential problem. Utilizing this paper as an aid to enhance operation of a PSK demodulator will bring a user one step closer to understanding the complexity of its design.
    • FQPSK-L: An Improved Constant Envelope Modulation Scheme for QPSK

      Lee, Tong-Fu; Wang, Shih-Ho; Liu, Chia-Liang; Bao, Liu; University of California Davis; Industrial Technology Research Institute; Tianjin University (International Foundation for Telemetering, 1998-10)
      A new constant envelope modulation scheme and architecture for QPSK by cubic spline interpolation methods which increase spectral efficiency and power efficiency, named FQPSK-L, is presented. This modulation technique is an extension of the Feher Quadrature Shift Keying (FQPSK) patented technologies, see Ref [1]. Being a constant envelope modulation, FQPSK-L can operate with class C power amplifier without spectrum regrowth. We achieve a more compact spectrum with comparable bit error rate performance. For example, FQPSK-L is about 20% more spectral efficient than GMSK BTb=0.3 from 40 to 70 dB attenuation point. Moreover, FQPSK-L intrinsically has spikes at fc ± 0.5fb, fc ± 1.0fb, fc ± 1.5fb, ... which are useful for carrier recovery, symbol time recovery and fading compensation. In Rayleigh fading channel, FQPSK-L outperform GMSK BTb=0.3 by 0.8 dB. FQPSK-L is an excellent scheme for wireless and satellite communications which require high spectral and power efficiency.
    • Real-Time Telemetry Network

      Chalfant, Timothy A.; Gurr, Richard; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      We need to begin to define what the future of point-to-point telemetry will be in the new world of wireless communications, increasing bandwidth requirements, the integration of test and training, and modeling and simulation (M&S) interacting with open air ranges. The Advanced Range Telemetry Program will introduce several new technologies to the telemetry community over the next several years, how will we use and build on them for the future? What kind of architecture will we need to be able to interact with the M&S and Training communities? How do we create that architecture and to what use would it be put by a test program? The answer, we believe, is to build the equivalent of a network in the sky. An extension of the Internet, in simplistic terms. The system under test (SUT), or the systems in training would become nodes of a large interactive network. Instead of the SUT being treated as something outside the sphere of control for the range, the SUTs onboard instrumentation systems would become an integral part of the greater range complex. This paper will address what the architecture of a real-time telemetry network might look like and how it could be implemented within the telemetry community.

      Dongkai, Yang; Qishan, Zhan; Lung, Cheng Lee; Beijing University of Aeronautics and Astronautics; City University of Hong Kong (International Foundation for Telemetering, 1998-10)
      An Improved AMI (Alternate Mark Inverse) Code used in telemetry system is proposed, its implementation and properties analysis are reported, including error performance analysis, power spectrum analysis, the relationship between acqusition probability of the first frame marker and error threshold and length of frame marker, etc. This type of code has the approximately identical power spectrum performance as the AMI Code. In addition, there have no long continuous zeroes in the data stream, which will cause phase-locked loop to fail. Using the Improved AMI Code, the equal probability of 0 and 1 is changed, which will increase acqusition probability of the first frame marker. Detailed description about how to create the Improved AMI Code is also discussed in this paper.

      Glim, Carl; Universal Space Network, Inc. (International Foundation for Telemetering, 1998-10)
      The recent proliferation of Low Earth Orbiting (LEO) science, earth resources, and global communication satellites requires a significant number of ground stations for support. A network of satellite tracking ground stations with the ability to support multiple users and communicate with multiple satellites requires a robust scheduling and conflict resolution system. This paper describes an automated scheduling implementation for managing such a commercial, multi-user, multiple satellite, ground station network.

      Drews, Michael E.; Forman, Douglas A.; Baker, Damon M.; Khazoyan, Louis B.; Viazzo, Danilo; Octant Technologies, Inc.; Boeing Information; Integrated Systems, Inc. (International Foundation for Telemetering, 1998-10)
      A real-time telemetry simulator of the IUS spacecraft has recently entered operation to train Flight Control Teams for the 1aunch of the AXAF telescope from the Shuttle. The simulator has proven to be a successful higher fidelity implementation of its predecessor, while affirming the rapid development methodology used in its design. Although composed of COTS hardware and software, the system simulates the full breadth of the mission: Launch, Pre-Deployment-Checkout, Burn Sequence, and AXAF/IUS separation. Realism is increased through patching the system into the operations facility to simulate IUS telemetry, Shuttle telemetry, and the Tracking Station link (commands and status message).

      Pingfang, Zheng; Qishan, Zhang; Lung, Cheng Lee; Beijing University of Aeronautics and Astronautics; City University of Hong Kong (International Foundation for Telemetering, 1998-10)
      With the rapid development of intelligent transport system in the world during the past few years, it promotes some navigation & location technology to a wide application especially in the car application. This paper firstly introduces some kinds of navigation & location systems and then analyzes the advantage and disadvantage of each system. On the basis of integrating every system and considering the high accuracy which can be achieved by adopting the technology based on DGPS (Differential Global Position System) at present, vehicle navigation & location system based on DGPS/INS/GIS integrated technology is put forward. The propound of this system shortens the distance between academic plan and real application greatly, and it provides a high accuracy and high reliability navigation & location system for traffic department and some car manufacturing Inc. In addition, this system is also provided with a friendly interface that makes it very easy to the manipulator or the user. The emphasis of this paper is put on the hardware and software of this system through introducing the system performance, the system component and the system software, and the characteristic of each module that makes up the whole system. The propound of the vehicle navigation & location system based on DGPS/INS/GIS integrated technology is a new attempt for development of intelligent transport system in our country, it will be sure to accelerate the process of our intelligent transport system.

      Briggs, James R.; Youssef, Ahmed H.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Optical trackers are often used at the Air Force Flight Test Center (AFFTC) and at other Department of Defense (DoD) ranges to collect video and trajectory data for real-time display and postflight processing. When optical trackers are used in remote areas, pointing data from radar is utilized to enable the trackers to initially acquire targets. To enable the trackers to use radar-pointing data, offsets to true north must first be known. This offset is taken into account given the current position of the optical tracker. During postflight processing, when determining the trajectory of the target, the offsets are also taken into account to produce an accurate trajectory solution. Current methods of determining offsets to true north are time consuming and involve a lot of guesswork. Typically, a map and a known landmark are used to determine the offsets to true north. Another method is to look for the North Star (Polaris) and input an estimated offset. This paper will describe an inexpensive, stand-alone system that utilizes the Global Positioning System (GPS) to determine these offsets. This device may be modified and integrated with other systems that may need to point accurately. For example, a gun barrel on a tank may need to point accurately to within a degree. This device may also be used to accurately position telemetry antennas.

      Billings, Don; Wei, Mei; Leung, Joseph; Aoyagi, Michio; Shigemoto, Fred; Honeyman, Rob; NASA; Recom Technologies (International Foundation for Telemetering, 1998-10)
      Although PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.