James, William G., Jr.; Eglin Air Force Base (International Foundation for Telemetering, 2002-10)
      The Central Control Facility at Eglin Air Force Base has acquired full intellectual rights to a single board telemetry card with device driver and test software. This card has an integrated IRIG 106 PCM decommutator, IRIG time clock and minimal PCM simulator capability using the latest in Field Programmable Gate Array technology. Eglin will offer this capability to the telemetry community as both open source hardware and software and solicit partnerships with both government and private industry for both open source and closed source for-profit products.

      Meyer, Steven J.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      The Joint Advanced Missile Instrumentation (JAMI) program is developing a Time, Space, and Position Information (TSPI) unit for high dynamic missile platforms by employing the use of Global Position System (GPS) and inertial sensors. The GPS data is uncoupled from the inertial data. The output of the JAMI TSPI unit follows the packet telemetry protocol and is called the TSPI unit message structure (TUMS). The packet format allows the data stream to stand on its own, be integrated into a packet telemetry system or be an asynchronous data channel in a PCM data stream. On the ground, the JAMI data processor (JDP) Kalman filters the GPS and inertial data to provide a real time TSPI solution to the ranges for display. This paper gives an overview of the message format, the timing relationships between the GPS data and inertial data, and how TUMS is to be handled by the telemetry receiving site to hand it off to the JDP.
    • Time-Tagging Issues Relating to Networked Data Acquisition Systems

      Owens, Tara; Berard, Alfredo; Boolos, Tim; Eglin Air Force Base (International Foundation for Telemetering, 2002-10)
      The CENTS Program is a Central Test and Evaluation Investment Program (CTEIP) effort conducted by the 46th Test Wing at Eglin Air Force Base, Florida. The project uses advanced internetworking technology to collect data unobtrusively from multiple sensors located throughout the aircraft without the time and expense of installing new wires. The sensors are used to unobtrusively extract data from several Line Replaceable Units (LRU’s). The harvested data is then transported to a master network controller using the existing aircraft power lines. A critical aspect of networked data acquisition is time-tagging the data so that the data timeline can be reconstructed to a specified resolution at the conclusion of the tests. This paper will discuss the time-tagging issues that arise when developing a networked data acquisition system, especially how they relate to the current effort to develop a power line based data acquisition network. In addition this paper will detail the scheme currently being tested to time tag data in the Common Event Network Test-Instrumentation System (CENTS) developed by the 46 TW/TSI Flight Test Division, Air Armament Center, Eglin AFB, FL.

      Crummett, Ronald C.; Jensen, Michael A.; Rice, Michael D.; Brigham Young University (International Foundation for Telemetering, 2002-10)
      The use of two antennas on an aeronautical telemetry transmitter is a common practice for overcoming signal obstruction that can occur during air vehicle maneuvering. However, this practice also leads to interference nulls that can cause dramatic degradation in the average signal integrity. This paper discusses the application of a transmit diversity scheme capable of overcoming this interference problem. The development leads to symbol error probability expressions that can be applied to assess the performance of the scheme relative to that of traditional schemes. Representative computational examples demonstrate the potential of the method.

      De Selms, Tom; Veridian Engineering (International Foundation for Telemetering, 2002-10)
      Using acquisition networks requires an understanding of the capabilities, design constraints and limitations of each available network device. The proper use of bridges, routers and gateways become extremely important in large networks where dissimilar busses, protocols or applications may be found. As data acquisition networks become a reality, the instrumentation network engineer must understand the benefits of each of these network devices and when to use them.

      Chakraborti, Anirban; New Mexico State University (International Foundation for Telemetering, 2002-10)
      The current challenge has been to develop and adapt commercial Internet protocols for usage in space communications. Commercialized solutions, rather than Customized ones are cheaper, have low turnaround time and offer higher flexibility in deployment and operation. The focus of the study was to modify and develop UDP/IP based protocols commonly used in commercial Internet for reliable data transfers in space environment. Multicast Dissemination Protocol was designed by Naval Research Laboratory to provide reliable multicast data and file transfer delivery on the top of general UDP/IP platform. It is very suited for bulk data transfer over the Internet. We have extended its usage in space channels and evaluated it as a solution to meet key challenges in space communications like high bit error rates and asymmetric channels. We have also tried to optimize the performance of the protocol in the terms of throughput, reliability, integrity and security of data. The evaluation test were carried on our Space to Ground Link Simulator which uses PPP to model point to point satellite links and correspond to low capacity systems as found in small satellite systems.

      Xu, Liu; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      The Vehicle Monitoring System based on GPRS is a system using GPRS network to transmit data, including location data, time data and so on .It has many advantages compared with those systems based on other communication modes. The key of the system lies in how to build up the connection with exterior data network. In this paper, the constitution of the system is introduced, and the course of building up connection with exterior data network is described in detail.
    • Waveform Description Language (WDL) for Software Radios

      Prill, Robert; Comba, Andrew; BAE SYSTEMS Communications, Navigation, Identification (International Foundation for Telemetering, 2002-10)
      Waveform Description Language (WDL) was invented to ease the process of porting legacy and/ or new radio waveforms to Programmable / Software Radios. WDL has two primary requirements; 1st it is to provide a rigorous executable behavioural description of waveform signal structures that is unambiguous and yet independent of any particular end item software radio architecture. The 2nd requirement is that the behavioural specification provides a path to automatic code generation for GP’s, DSP’s, and FPFG’s and that the Generated code be tested against the behavioural model.

      Berard, Alfredo J.; Chalfant, Tim; Lloyd, Joe; Small, Marty; Buckley, Mark; Bagó, Balázs; Lockard, Michael; Eglin Air Force Base; Edwards Air Force Base; Navair; et al. (International Foundation for Telemetering, 2002-10)
      For the last 30 years Magnetic Tape Systems have been the primary means of recording data from airborne instrumentation systems. Increasing data rates and harsh environmental requirements have often exceeded the ability of tape-based systems to keep pace with platform technology. This paper examines operational and data reduction benefits when employing the IRIG 106 Chapter 10 Solid State Recorder Standard introduced by the Range Commanders Council (RCC) Telemetry Group (TG). The Standard and this paper address media formatting, data formatting for a variety of different data types, data downloading, and data security, along with serial command and control and discrete command and control of the recorder. This paper also addresses software data processing and raw data reconstruction of Chapter 10 data.

      Rice, Michael; Davis, Adam; Bettwieser, Christian; Brigham Young University (International Foundation for Telemetering, 2002-10)
      This paper is the first of two papers that present a multipath channel model for wideband aeronautical telemetry. Channel sounding data, collected at Edwards AFB, California at both L-Band and lower S-Band, were used to generate channel model. In Part 1, analytic and geometric considerations are discussed and the frequency domain modeling technique is introduced. In Part 2, the experimental results are summarized and a channel model composed of three propagation paths is proposed.

      Rice, Michael; Davis, Adam; Bettwieser, Christian; Brigham Young University (International Foundation for Telemetering, 2002-10)
      This paper is the second of two papers that present a multipath channel model for wideband aeronautical telemetry. Channel sounding data were collected at Edwards AFB, California at both L-Band and lower S-Band. Frequency domain analysis techniques were used to evaluate candidate channel models. The channel model is composed of three propagation paths: a line-of-sight path, and two specular reflections. The first specular reflection is characterized by a relative amplitude of 70% to 96% of the line-of-sight amplitude and and a delay of 10 – 80 ns. This path is the result of “ground bounces” off the dry lake bed at Edwards and is a typical terrain feature at DoD test ranges located in the Western USA. The amplitude and delay of this path are defined completely by the flight path geometry. The second path is a much lower amplitude path with a longer delay. The gain of this path is well modeled as a zero-mean complex Gaussian random variable. The relative amplitude is on the order of 2% to 8% of the line-of-sight amplitude. The mean excess delay is 155 ns with an RMS delay spread of 74 ns.
    • Wireless Local Area Network for Data Telemetry from Fast Moving Nodes

      Bamberger, Robert J.; Barrett, George R.; Nichols, Robert A.; Burbank, Jack L.; Lauss, Mark H.; Johns Hopkins University; U.S. Army Yuma Proving Ground (International Foundation for Telemetering, 2002-10)
      A Wireless Local Area Network (WLAN) based system called 2-Way Robust Acquisition of Data (2-RAD) is being developed to telemeter data from a number of fast moving airborne platforms to ground collection points distributed over a large test range. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) is analyzing a 2-RAD prototype currently in operation at the U.S. Army Yuma Proving Ground (YPG) that uses an IEEE 802.11b WLAN infrastructure. Preliminary analysis efforts at JHU/APL indicate that the Doppler shift from fast movers, and the system radio link margin, do not preclude IEEE 802.11b from being used for 2 -RAD.