• USING BRIDGES, ROUTERS AND GATEWAYS IN DATA ACQUISITION NETWORKS

      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.
    • USING MDP FOR TELEMETRY DATA TRANSFERS

      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.
    • THE VEHICLE MONITORING SYSTEM BASED ON GPRS

      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.
    • WHO MOVED MY TAPE RECORDER FLAVORED CHEESE

      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.
    • A WIDEBAND CHANNEL MODEL FOR AERONAUTICAL TELEMETRY — PART 1: GEOMETRIC CONSIDERATIONS AND EXPERIMENTAL CONFIGURATION

      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.
    • A WIDEBAND CHANNEL MODEL FOR AERONAUTICAL TELEMETRY — PART 2: MODELING RESULTS

      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.