Olyniec, Lee; Edwards Air Force Base (International Foundation for Telemetering, 1995-11)
      This paper describes the design and characteristics of a digital voice encoding circuit that uses the continuously variable slope delta (CVSD) modulation/demodulation method. With digital voice encoding, the audio signal can be placed into the pulse code modulation (PCM) data stream. Some methods of digitizing voice can require a large amount of bandwidth. Using the CVSD method, an acceptable quality of audio signal is obtained with a minimum of bandwidth. Presently, there is a CVSD microchip commercially available; however, this paper will describe the design of a circuit based on individual components that apply the CVSD method. With the advances in data acquisition technology, increased bit rates, and introduction of a corresponding MIL-STD, CVSD modulated voice will become more utilized in the flight test programs and a good knowledge of CVSD will become increasingly important. This paper will present CVSD theory, supported by graphical investigations of a working circuit under different conditions. Finally, several subjects for further study into CVSD will be addressed.
    • RTPS Telemetry - Simulator Link at Naval Air Warfare Center

      McNamara, William G.; Stanley, Page; Nichols, Jay (International Foundation for Telemetering, 1995-11)
      Over the last 3 years the Naval Air Warfare Center Aircraft Division (NAWCAD), Patuxent River, MD, has been in the process of developing a link between its secure Manned Flight Simulator (MFS) and Real Time Processing System (RTPS) facilities. The MFS hosts a wide variety of high fidelity fixed and rotary wing aircraft simulation models. The RTPS is used as a telemetry ground station for conduct of Navy flight testing at Patuxent River MD. The ability to integrate simulation with flight testing in a real time environment provides new potential for increased flight safety, enhanced engineering training, optimized flight test planning, real time simulation fidelity assessments, improved engineering analysis and other applications for enhanced flight testing, data analysis and data processing. A prototype system has been successfully designed and operated at NAWCAD in support of an F/A-18C flight test project which required simultaneous merging and display of real time and simulation data to reduce the risk of departure from controlled flight. As currently designed the link (encryption and decryption gear in the loop) can be operated in three modes: (1) Simulation sending data to RTPS (e.g. pilot-engineer pre-first flight preparation/training scenario, (2) simulation is driven by real aircraft control surface inputs and response is compared with that of the real aircraft for simulation fidelity assessments and (3) simulation "rides along" with the real aircraft and data are extracted from the simulation which are otherwise unavailable from the aircraft (e.g. flight control law interconnect signals, control law feedback signals, aerodynamic data, propulsion model data, avionics model data, other model data etc.). This paper discusses, design and implementation aspects of the RTPS-Simulator link, and includes a description of how the link was used to support a real time flight test program by providing critical safety of flight data. Other potential uses for the link will also be highlighted.

      Cirineo, Tony; Troublefield, Bob; NAWCWPNS (International Foundation for Telemetering, 1995-11)
      This paper describes an Engineering Development Model (EDM) for the Standard Interoperable Datalink System (SIDS). This EDM represents an attempt to design and build a programmable system that can be used to test and evaluate various aspects of a modern digital datalink. First, an investigation was started of commercial wireless components and standards that could be used to construct the SIDS datalink. This investigation lead to the construction of an engineering developmental model. This model presently consists of wire wrap and prototype circuits that implement many aspects of a modern digital datalink.
    • Object-Oriented Design of a Windows™ Based Automated Telemetry System

      Self, Lance P. L.; NAWC-Weapons Division (International Foundation for Telemetering, 1995-11)
      This paper illustrates a Windows computer application program which uses the object-oriented paradigm as a basis. The objective of the application program is to control the setup of equipment involved in routing a telemetry signal. This design uses abstract classes as high level building blocks from which site specific classes are derived. It is the next generation to the software portion of a system described by Eugene L. Law. The object-oriented design method, as presented by Grady Booch in his book Object-Oriented Analysis and Design with Applications, is the design tool.

      Glenn, Tom; Chavez, Tomas; Toole, Michael T.; Markwardt, Jack (International Foundation for Telemetering, 1995-11)
      The Ballistic Missile Defense Organization (BMDO) is developing new Theater Missile Defense (TMD) weapon systems to defend against the rapidly expanding ballistic missile threat. The tactical ballistic missile threats include systems with range capabilities greater than 1000 kilometers. The development and testing of systems such as the Patriot Advanced Capability 3 (PAC-3), the Theater High Altitude Area Defense (THAAD), Navy Area Defense, and the System Integration Tests (SIT) to address the interoperability of this family of systems, will require the development of the Transportable Range Augmentation and Control System for Multiple Shot Engagements (TRACS - MSE). Congress has mandated that these systems be tested in multiple simultaneous engagements. These systems will be tested at several ranges to meet all the developmental and operational testers' needs. Potential range locations include White Sands Missile Range (WSMR), Kwajalein Missile Range (KMR), the Pacific Missile Range Facility (PMRF) and the Gulf Range at Eglin Air Force Base. Due to the long distances separating the target launch site and the interceptor site, the TRACS - MSE will be required at multiple sites for each range used. To be cost effective, transportable systems should be developed to augment existing capabilities. Advances in Global Positioning System (GPS) technology and high data rate receivers make telemetry based solutions attractive. This article will address the requirements for range safety, for Time, Space, Position Information (TSPI) collection and processing requirements to support a TRACS - MSE capability.

      Osborne, William P.; Ara, Sharmin; New Mexico State University (International Foundation for Telemetering, 1995-11)
      The national telemetry ranges are being pushed to provide higher data rate telemetry services by users with increasingly complex test procedure for increasingly complex weapon systems. At the same time they are having trouble obtaining more spectrum in which to provide these higher rates because of the demand for spectrum in SHF range from various mobile/cellular Personal Communications Services (PCS) as well as congress’s desire to auction spectrum and to transfer as much spectrum as possible to commercial uses. In light of these pressures the industry is in need of a modulation standard that will out perform the existing PCM/FM standard. The motivation for the present review and analysis of the performance of various coded/uncoded modulation schemes arises from this issue. Comparison of the performance of these schemes will be utilized in the following work to find a suitable solution to the existing problem.
    • Test and Evaluation Community Network (TECNET)

      Hurlburt, George F. (International Foundation for Telemetering, 1995-11)
      The Test and Evaluation Community Network (TECNET) has existed as a means of electronically exchanging unclassified information between Test and Evaluation (T&E) practitioners since 1983. The test and evaluation community in the Department of Defense (DoD) is heavily reliant on telemetry products. Thus, it is no surprise that TECNET deals substantively with telemetering matters. TECNET currently provides unclassified electronic mail, bulletin board, file manipulation and information retrieval services to the Test and Evaluation (T&E) community via an unclassified host computer operated and maintained by the Naval Air Warfare Center - Aircraft Division, Patuxent River, Maryland and a classified host computer located at the Aberdeen Proving Ground, Aberdeen, Maryland. National packet switched network capabilities are provided via the MILNET component of the Defense Data Network (DDN), the Defense Research Engineering Network (DREN) and a the Federal Telephone System for 2000 (FTS -2000) data network. The second TECNET computer provides a system high secret secure capability for TECNET via STU -III dial-up and the Defense Secure Network (DSNET) component of DDN. TECNET is a Joint Service network operating under the auspices of a tri-service Steering Committee which reports to a Board of Operating Directors (BoOD). TECNET supports a number of capabilities for the Range Commander's Council (RCC) community, including all scheduling for the RADCAL satellite. Presently TECNET supports a growing population of over 7,000 validated users from service Program Management Offices (PMO) and both the operational and developmental T&E communities in all the services. In the future TECNET envisions support to test planning, execution and reporting through the use of protected Multi -Level Secure (MLS) communication channels. This capability will dispense meaningfully detailed T&E related data bases and tools. The ability to provide needed, accurate, protected, high integrity, value added information at the right time and place and in the right format with the right amount of detail to the right decision makers adds direct value to the T&E process. In essence, the capability enhances the efficiency of the entire T&E process by making timely T&E information and tools more available to both its practitioners and consumers.
    • The Omni-Directional Differential Sun Sensor

      Swartwout, Michael; Olsen, Tanya; Kitts, Christopher; Stanford University (International Foundation for Telemetering, 1995-11)
      The Stanford University Satellite Systems Development Laboratory will flight test a telemetry reengineering experiment on its student-built SAPPHIRE spacecraft. This experiment utilizes solar panel current information and knowledge of panel geometry in order to create a virtual sun sensor that can roughly determine the satellite's sun angle. The Omni-Directional Differential Sun Sensor (ODDSS) algorithm normalizes solar panel currents and differences them to create a quasi-linear signal over a particular sensing region. The specific configuration of the SAPPHIRE spacecraft permits the construction of 24 such regions. The algorithm will account for variations in panel outputs due to battery charging, seasonal fluctuations, solar cell degradation, and albedo affects. Operationally, ODDSS telemetry data will be verified through ground processing and comparison with data derived from SAPPHIRE's infrared sensors and digital camera. The expected sensing accuracy is seven degrees. This paper reviews current progress in the design and integration of the ODDSS algorithm through a discussion of the algorithm's strategy and a presentation of results from hardware testing and software simulation.

      Dye, Ricky G.; Horne, Lyman D.; Brigham Young University (International Foundation for Telemetering, 1995-11)
      The aeronautical channel model is a good candidate for modeling the effects of multipath interference of telemetry signals on test ranges. The aeronautical fading channel model is parameterized by the signal to noise ratio, the Doppler shift and time delay between the specular and direct components, the specular to direct power ratio, the direct to diffuse power ratio, and the bandwidth of the multipath fading process. Segments of weighting signal data measured during a test at Tyndall AFB provide data which can be used to determine typical values of the above parameters in a variety of telemetering environments. In this paper, the set of parameters which most closely model the actual telemetry channel using the Tyndall data is determined.
    • Multi-functions Integration and Intermodulation Interference of TT&C system

      Jiaxing, Liu; The Southwest Insititute of Electronics Technology (International Foundation for Telemetering, 1995-11)
      This paper describes technical problems in system integration, Intermodulatin interference, digitalization, obital accuracy, low-noise design of the new generation TT&C system as well as their solutions.
    • The Impact of Telemetry on Radio Astronomy

      Janes, Clinton C. (International Foundation for Telemetering, 1995-11)
      The National Radio Astronomy Observatory (NRAO) operates the Very Large Array (VLA) Radio Observatory in New Mexico, and the Very Long Baseline Array (VLBA) with 10 radio antenna in locations from Hawaii to St. Croix, as well as other radio telescopes at Green Bank, West Virginia, and the 12 meter radio antenna near Tucson, AZ. Although radio frequency (RF) bands have been set aside for passive use by these radio telescopes, harmful interference from increased demands on the radio spectrum is a growing problem for earth-based radio astronomy. For example, locating a radio observatory in a remote area is little defense from satellite downlink telemetry. This paper describes why the operation of the radio telescopes is susceptible to RF telemetry interference, what bands are particularly vulnerable and at what power levels, and how data collection and centralized control of the arrays are accomplished without RF telemetry.
    • Survey of Internet Telemetry Applications

      Schooley, Larry C.; Caudle, Scott E.; University of Arizona (International Foundation for Telemetering, 1995-11)
      The Internet, as the online worldwide connection of computers has come to be known, has now grown to the point of emergence as a major tool in many applications. It will soon become, if it has not already become, an indispensable source of information and interaction for scientists and business people alike. The use of the Internet's various protocol's, including mail, newsreader, and file transfer, produces a global interconnectedness that is impossible to achieve in any other fashion. It is also important to realize that the Internet is currently doubling in size every year and will continue to grow at an extremely accelerated rate for at least the next five years. It is therefore important to be aware of the various applications made possible by use of the Internet, and of the potential for telemetry related uses.
    • High Performance CCSDS Processing Systems for EOS-AM Spacecraft Integration and Test

      Brown, Barbara; Bennett, Toby; Betancourt, Jose; NASA, Goddard Space Flight Center; RMS Technologies (International Foundation for Telemetering, 1995-11)
      The Earth Observing System-AM (EOS-AM) spacecraft, the first in a series of spacecraft for the EOS, is scheduled for launch in June of 1998. This spacecraft will carry high resolution instruments capable of generating large volumes of earth science data at rates up to 150 Mbps. Data will be transmitted in a packet format based upon the Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations. The Data Systems Technology Division (DSTD) at NASA's Goddard Space Flight Center (GSFC) has developed a set of high performance CCSDS return-link processing systems to support testing and verification of the EOS-AM spacecraft. These CCSDS processing systems use Versa Module Eurocard bus (VMEBus) Very Large Scale Integration (VLSI)-based processing modules developed for the EOS ground segment to acquire and handle the high rate EOS data. Functions performed by these systems include frame synchronization, Reed-Solomon error correction, fill frame removal, virtual channel sorting, packet service processing, and data quality accounting. The first of the systems was delivered in October 1994 to support testing of the onboard formatting equipment. The second and third systems, delivered in April 1995, support spacecraft checkout and verification. This paper will describe the function and implementation of these systems.

      Richard, Gaetan C.; Gonzales, Daniel G.; Malibu Research, Inc. (International Foundation for Telemetering, 1995-11)
      The use of low windload FLAPS™ antennas in telemetry tracking systems yields sizable savings in system cost due to the reduced requirements imposed on the pedestal assembly and on the underlying support structure. Traditionally the use of these antennas has been limited to applications in which frequency bandwidths did not exceed 10-13%. This paper describes a variation of the FLAPS™ technology which allows operation over bandwidths in excess of 35% and makes it usable in broadband systems. Two new applications are feasible: one for a ground based telemetry system operating in the 1435-1850 or 1750-2400 MHz band and one for a shipboard satellite communication system operating in the 4000-6000 MHz band.

      Reed, Ryan; Long, David G.; Arnold, David V. (International Foundation for Telemetering, 1995-11)
      A scatterometer is a radar system designed to make precise measurements of the magnitude of the radar echo scattered from surface. If the measurement is made over the ocean's surface, the surface wind speed and direction can be inferred. In order to better understand the relationship between the radar return and the ocean winds we have developed a unique ultra-wide band research scatterometer known as Yscat. The Yscat radar system is computer controlled, with a separate computer collecting environmental data. During a typical deployment, such as a recently completed 7 month deployment on Lake Ontario, the radar system is required to operate unmanned for weeks at a time, collecting data at a rate of up to 2 GB per week. Controlling such a complex system, and handling such large amounts of data presents a challenging remote operation problem. We used a novel combination of personal computers, telephone controlled switches, modems, and off the shelf software packages to enable us to perform daily monitoring, trouble shooting, and data transfer via a simple telephone connection. Data was stored on 4 mm DAT tapes for weekly pickup by a technician. This paper describes the Yscat system and our approach to control, monitoring, and data storage. While our approach is relatively "low tech", it has been very cost effective. This type of approach may be of interest to other designers of unique instrumentation at remote sites.

      Cullen J. M.; Keller, Ed; Eglin Air Force Base (International Foundation for Telemetering, 1995-11)
      The Instrumentation Technology Branch of Wright Laboratory Armament Directorate (WL/MNSI), has successfully completed an Exploratory Development (6.2) program to develop Subminiature Telemetry (SMT). SMT is a flexible, programmable telemeter with self calibration, power control and Direct Sequence Spread Spectrum modulation. The development program successfully demonstrated the ability of the SMT system to collect up to 64 analog and/or 128 digital discrete signals with programmable gain, bandwidth and offset. The program demonstrated a spread spectrum multiple-access technique that allows for simultaneous transmission and receipt of up to 96 different telemetry units within a 100 MHz telemetry band. WL/MNSI is conducting an Advanced Technology Development (6.3) program to continue development in this area. An air-worthy 4 channel spread spectrum demodulator was developed to support the SMT program but it is too costly for ground applications. The goals of this effort are to reduce the demodulator cost by a factor of 10 while increasing the capability for simultaneously processing data from 24 telemetry units and to support the first Technology Transition Plan (TTP) between WL/MN and the Air Force Development Test Center (AFDTC). The TTP will facilitate the transition of SMT spread spectrum technology to AFDTC for mission support over the next three years.

      Law, Eugene L.; NAWCWPNS (International Foundation for Telemetering, 1995-11)
      This paper will present and compare several definitions of telemetry radio frequency (RF) signal bandwidth. Measured spectra for different signals will be presented. The bandwidths of these signals will then be determined and measurement methods will be discussed. This discussion will include the effects of spectrum analyzer resolution bandwidth, video bandwidth and detector type. Finally, a proposed spectral mask will be discussed. This spectral mask can be used to calculate the required attenuation for a given frequency offset from the center frequency. The required attenuation is a function of the the bit rate or maximum frequency of interest and the transmitter power. This spectral mask is proposed to be part of the next edition of the Telemetry Standards, Inter-Range Instrumentation Group (IRIG) Standard 106.

      Thursby, William R. Jr; Shirley, Benjamin M.; Eglin Air Force Base (International Foundation for Telemetering, 1995-11)
      Eglin Air Force Base (AFB) plans to demonstrate subminiature telemetry (SMT) spread spectrum technology, via an upgraded prototype SMT system, to validate its cost-effectiveness for both Department of Defense (DoD) and commercial use. The goal is to develop new and/or modify current SMT instrumentation using existing production methods to provide increased capabilities at lower costs and reduced size. The transmitter is to require less than 2 cubic inches of space and have a cost goal of $500/unit "in quantity." The cost goal of a ground-based, 24-channel capable ground receiver is $4000/unit "in quantity". The SMT project as well as its schedule, flight and ground demonstrations, validation criteria and goals, and various benefits are discussed.

      Long, David G. (International Foundation for Telemetering, 1995-11)
      A radar scatterometer transmits a series of RF pulses and measures the total-power (energy) of the backscattered signal. Measurements of the backscattered energy from the ocean's surface can be used to infer the near-surface wind vector [7]. Accurate backscatter energy measurements are required to insure accurate wind estimates. Unfortunately, the signal measurement is noisy so a separate measurement of the noise-only total-power is subtracted from the signal measurement to estimate the echo signal energy. A common metric for evaluating the accuracy of the scatterometer energy measurement is the normalized signal variance, termed K(p). In designing a scatterometer tradeoffs in design parameters are made to minimize K(p). Spaceborne scatterometers have traditionally been based on fan-beam antennas and CW modulation for which expressions for K(p) exist. Advanced pencil-beam scatterometers, such as SeaWinds currently being developed by NASA use modulated Signals so that new K(p) expressions are required. This paper outlines the derivation of the generalized K(p) expression. While very complicated in its exact form, with a simplified geometry the K(p) expression can be related to the radar ambiguity function. The resulting analysis yields insights into the tradeoffs inherent in a scatterometer design and permits analytic tradeoffs in system performance.

      Farmer, Mike; Culver, Randy; Loral Federal Services Corporation (International Foundation for Telemetering, 1995-11)
      Satellite operations have been inherently manpower intensive since they began over thirty years ago. Since manpower intensive equates to costs, this mode of operations cannot survive in light of government budget cuts and commercial profitability. Two factors are now key for both government and commercial satellite control centers: 1) systems must be highly automated to minimize the operations staff, and 2) these automated systems must be deployed and enhanced at a low cost. This paper describes the three principle challenges which arise in migrating from high-cost, manpower intensive satellite operations to low-cost, automated satellite operations and makes recommendations for solving them.