• International Telemetering Conference Proceedings, Volume 42 (2006)

      International Foundation for Telemetering, 2006-10
    • ADVANTAGES OF GPS OVER RADAR IN WIND WEIGHTING OF UNGUIDED SOUNDING ROCKETS

      May, Linda R.; Honeywell Technology Solutions, Inc.; NASA Goddard Space Flight Center (International Foundation for Telemetering, 2006-10)
      “Wind Weighting” is the process of assessing the effect of wind on a launch vehicle and determining launcher settings which would counteract that effect. This paper discusses the advantages of using GPS radiosondes to determine wind profiles over the historical method of tracking balloon positions with radar for the purposes of Wind Weighting. The primary advantages are lower costs and greater portability. Also presented is evidence of improved accuracy and reliability. Engineering testing is described and test results are reported.
    • Single Bounce Air to Ground Communication Channel Capacity for MIMO Applications

      Kosbar, Kurt; Potter, Chris; University of Missouri (International Foundation for Telemetering, 2006-10)
      This paper addresses the air-to-ground communication problem, where multiple transmit antennas are used on the aircraft to combat multi-path interference. The channel is assumed to have a line-of-sight component and a single ground reflection. Multiple input multiple output (MIMO) techniques can be used in this situation, to increase the reliability and data rate. In this paper we discuss how the MIMO channel capacity changes, with the aircraft antenna configuration, altitude, velocity, range, and a number of other parameters. For comparison, the MIMO results are compared to systems which have single antennas at the transmitter, at the receiver, or at both ends.
    • The SoftDecom Engine

      Benitez, Jesus; Guadiana, Juan; Torres, Miguel; Creel, Larry; White Sands Missile Range (International Foundation for Telemetering, 2006-10)
      The software decommutator was recently fielded at White Sands to address the requirements of a new missile test program. This software decommutator is rewritten as a simple C program Function or Class with a simple interface. The function and an Interface Control Definition (ICD) comprise the SoftDecom Engine (SDE). This paper addresses how an SDE can deliver Enterprise Wide Portability, not only that of the SDE, but more importantly a test program!s Verification & Validation (V&V). The crux of the portability issue is reduced to defining the interface of the SDE. In the simplest manifestation only two interfaces are needed and one is a given. The input structure is defined by the telemeter minor frame with time appended if desired. The output structure is no more than an array containing the parameters required. The ICD could be generalized into a standard for most applications, but that isn!t necessary, as the structures are simple, hence easy to adapt to anyway. This new paradigm!s importance will flourish on industries irreversible migration to faster and more complex telemeters. The paper reviews the relative ease that software exhibits when addressing very complex telemeters. With confidence it may be said “ if the telemeter format can be described in writing, it can be processed real time”. Also discussed are tasks that normally require specialized or customized and expensive equipment for example, merged streams, complex simulations and recording and reproducing PCM (sans recorder). Hopefully, your creativity will be engaged as ours has been.
    • AD-HOC WIRELESS NETWORKS: A COMMERCIALISATION CASE STUDY

      Rogers, Derek; University of South Australia (International Foundation for Telemetering, 2006-10)
      This paper presents a case study of the commercialisation of an ad-hoc wireless network technology from a subsidiary of a multinational company. The paper does not disclose any intellectual property specifics, the organisations or individuals involved. Instead the paper focuses on generic issues associated with technology transfer; exploration of market opportunities, market validation, the identification of a novel business model and economic validation. The paper wraps the case study within the academic context of commercialisation providing substantive literature sources, tools and techniques for readers faced with similar challenges; tools and techniques that can be applied irrespective of the underlying technology.
    • DEVELOPMENTAL FLIGHT INSTRUMENTATION SYSTEM FOR THE CREW LAUNCH VEHICLE

      Crawford, Kevin; Thomas, John; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (International Foundation for Telemetering, 2006-10)
      The National Aeronautics and Space Administration is developing a new launch vehicle to replace the Space Shuttle. The Crew Launch Vehicle (CLV) will be a combination of new design hardware and heritage Apollo and Space Shuttle hardware. The current CLV configuration is a 5 segment solid rocket booster First Stage and a new Upper Stage design with a modified Apollo era J-2 engine. The current schedule has an Ascent Development Test Flight (ADFT-0) with a First Stage and a dummy structurally identical, but without engine, Upper Stage. The ADFT-0 test results will determine if there will be multiple ADFT flights. There will be a minimum of two test flights with a full complement of flight hardware. After the completion of the test flights, the first manned flight to the International Space Station is scheduled for late 2014. To verify the CLV’s design margins a developmental flight instrumentation (DFI) system is needed. The DFI system will collect environmental and health data from the various CLV subsystems’ and either transmit it to the ground or store it onboard for later evaluation on the ground. The CLV consists of 4 major elements: the First Stage, the Upper Stage, the Upper Stage Engine and the integration of these elements together. It is anticipated that each of CLV’s elements will have some version of DFI. This paper will discuss a conceptual DFI design for each element and also of an integrated CLV DFI system.
    • CELLULAR BROADBAND TELEMETRY OPTIONS FOR THE 21st CENTURY: Looking at broadband cellular from a telemetry perspective

      Smith, Brian J.; Omniwav Mobile, Inc. (International Foundation for Telemetering, 2006-10)
      With the recent broadband upgrades to various cellular infrastructures and the myriad new emerging wireless broadband standards and services offered by carriers, it is often difficult to navigate this sea of technology. In deciding the best choice for broadband telemetry applications, one must look not only at the technology, but also at the economics, market timing, bandwidths, legacy issues, future expandability and coverage, security, protocols, and the requirements of the specific application. This paper reviews the technology roadmap of cellular providers keeping these issues in perspective as they apply to TCP/IP data for images, audio, video, and other broadband telemetry data using CDMA 1xRTT, EV-DO, and EV-DO Rev A systems as well as GSM GPRS/EDGE, UMTS/W-CDMA, HSDPA, and HSUPA networks. Lastly, issues seen by system integrators when using cellular channels for telemetry applications are examined, and a case is presented for overcoming many of these issues through the use of cellular routers.
    • ACHIEVING HIGH-ACCURACY TIME DISTRIBUTION IN NETWORK-CENTRIC DATA ACQUISITION AND TELEMETRY SYSTEMS WITH IEEE 1588

      Grim, Evan T.; Southwest Research Institute (International Foundation for Telemetering, 2006-10)
      Network-centric data acquisition and telemetry systems continue to gain momentum and adoption. However, inherent non-deterministic network delays hinder these systems’ suitability for use where high-accuracy timing information is required. The emerging IEEE 1588 standard for time distribution offers the potential for real-time data acquisition system development using cost-effective, standards-based network technologies such as Ethernet and IP multicast. This paper discusses the challenges, realities, lessons, and triumphs experienced using IEEE 1588 in the development and implementation of such a large-scale network-centric data acquisition and telemetry system. IEEE 1588 clears a major hurdle in moving the network-centric buzz from theory to realization.
    • IMPORTANCE OF “ACCURATE” TIME TO TEST AND MEASUREMENT OF COMPLEX DYNAMIC SYSTEMS

      Blakely, Patrick A.; The Boeing Commercial Airplanes (International Foundation for Telemetering, 2006-10)
      This paper discusses the importance of time measurement and the necessity of time measurement accuracy to data acquisition and analysis. It briefly reviews how time is used in data analysis and how to determine what amount of jitter, latency and phase error is acceptable for various data acquisition systems and analysis methodology. It discusses the relevance of various measurement timing errors and how some of them may be corrected. Finally, this paper discusses various approaches to time tagging of measurements in a distributed network based data system where data is packetized for efficient transmission.
    • How to Estimate the Unmodulated Carrier Power Level of a Modulated Telemetry Signal

      Law, Eugene; NAVAIR (International Foundation for Telemetering, 2006-10)
      This paper will present methods to both measure the unmodulated carrier power of a modulated signal and to estimate the unmodulated carrier power level from the measured power spectrum. The unmodulated carrier power level is needed to convert measured spectra into units of dBc.
    • INTERFERENCE MITIGATION AND CHANNEL EQUALIZATION FOR ARTM TIER-1 WAVEFORMS USING KALMAN FILTER

      Saquib, Mohammad; Popescu, Otilia; Popescu, Dimitrie C.; Rice, Michael; University of Texas; Brigham Young University (International Foundation for Telemetering, 2006-10)
      In this paper we describe a new method that is applicable to mitigating both multipath interference and adjacent channel interference (ACI) in aeronautical telemetry applications using ARTM Tier-1 waveforms. The proposed method uses a linear equalizer that is derived using Kalman filtering theory, which has been used for channel equalization for high-speed communication systems. We illustrate the proposed method with numerical examples obtained from simulations that show the bit error rate performance (BER) for different modulation schemes.
    • CPFSK, FQPSK-JR and ARTM CPM ON A ROCKET LAUNCH

      Wolf, Glen; Ortigoza, Saul; Streich, Ronald G.; Edwards Air Force Base (International Foundation for Telemetering, 2006-10)
      A rocket launch, as high dynamics target, was used to demonstrate X-band tracking and also to verify high bit rate frequency planning while demonstrating significant bandwidth reduction with IRIG standard advanced modulation methods. X-band tracking by a modified 8-foot mobile telemetry antenna was excellent. Three separate S-band transmitters with three separate wraparound antennas were launched as a piggyback payload on an Enhanced Orion sounding rocket at White Sands Missile Range (WSMR) to compare the performance of 10 Mbs and 20 Mbs bit error rate (BER) pattern data transmission from CPFSK, FQPSK-JR and ARTM CPM modulation formats under high dynamic conditions. The test is more remarkable in that another S-band wideband spread spectrum signal was also transmitted with good success. These results show that all three modulation methods performed well during ignition and liftoff, low aspect angle (receiving through the rocket motor plume during ascent from a tracker near the launch pad), spin stabilization antenna lobe fades and payload tumbling. Spectrum pictures are provided to show the dramatic reduction in transmission bandwidth from CPFSK to FQPSK-JR to ARTM CPM. Confirmation of the preflight RF adjacent channel interference planning procedures from IRIG 106-05 is described by spectrum pictures and data quality measurements.
    • FROM RF TO BITS WITH SYNTHETIC BEAMFORMING

      Kelkar, Anand; Lamarra, Norm; Gonzalez, Daniel; Creative Digital Systems; Malibu Research Associates (International Foundation for Telemetering, 2006-10)
      A Synthetic Beamforming antenna was built for Airborne Telemetry. Low-Noise Block-converters translated RF to IF suitable for direct analog-to-digital conversion. Then all telemetry functions were performed digitally via parallel FPGAs for 10 independent sources. Monopulse tracking and optimal diversity combination was performed using 4 antenna quadrants at two orthogonal polarizations. Novel estimation approaches drove digital demodulation, symbol- and bit- synchronization. Final telemetry outputs include: digital, analog (video), and analog IF (e.g., for downlink relay). This program has incubated several concepts that we believe have the combined potential to significantly improve the future of telemetry.
    • IS THERE A SHAPED OFFSET 8-PSK?

      Rice, Michael; Nelson, Tom; Brigham Young University (International Foundation for Telemetering, 2006-10)
      Motivated by the success of the ARTM Tier-1 modulation known as Shaped Offset QPSK, this paper examines whether improved spectral efficiency can be achieved using an a Shaped Offset 8PSK. Three possible interpretations of this question are examined and it is shown that there does not appear to be a shaped offset 8-PSK in the context of aeronautical telemetry.
    • PRAGMATIC GENERAL MULTICAST (PGM) FOR BANDWIDTH EFFICIENT, RELIABLE TELEMETRY DISTRIBUTION OVER IP NETWORKS

      Rolenc, David D.; Chang, Yong "Skip"; RT Logic Incorporated (International Foundation for Telemetering, 2006-10)
      As telemetry systems migrate toward network-centric distribution architectures, more efficient mechanisms are needed to distribute the telemetry data from the source to various users of the data. The most widely used network protocol for reliable delivery of telemetry data over IP networks is TCP/IP. With TCP/IP, the bandwidth required to distribute telemetry data increases linearly according to the number of point-to-point connections. An alternate approach to reliably deliver telemetry data to multiple end users in a network efficient manner is the Pragmatic General Multicast (PGM) protocol.
    • WHAT IF T&E HAD INFINITE SPECTRUM?

      Jones, Charles H.; Edwards Air Force Base (International Foundation for Telemetering, 2006-10)
      The availability of spectrum has been decreasing while requirements have been increasing. One way of answering the question of how much impact this has is to ask how much spectrum would be used in an ideal situation. A way of getting a handle on this question is to look at how much data is recorded onboard test vehicles. We can assume that, if we could, we would transmit everything we currently record. This would be ideal since we could then consider the onboard recorders as backup and we would have all data available in case of catastrophe. This paper looks at onboard recording and telemetry trends to see what percentage of data has been and will be telemetered. This analysis involves several levels in that telemetry requirements are not limited to transmission over a single frequency. It is common to have more than one vehicle involved in an operation. Thus, different scenarios are evaluated from single vehicle operations to larger scale test and training operations. When considered from this point of view, the impact becomes quite clear: the T&E community is making significant compromises on telemetering data. Therefore, current efforts to obtain more spectrum for telemetry use through the World Radio Conference are well justified.
    • JOINT INTERFERENCE SUPPRESSION AND QRD-M DETECTION FOR SPATIAL MULTIPLEXING MIMO SYSTEMS IN A RAYLEIGH FADING CHANNEL

      Tsai, Chiou-Wei; Cagley, Richard E.; Iltis, Ronald A.; University of California; Toyon Research Corporation (International Foundation for Telemetering, 2006-10)
      Spatial multiplexing (SM) systems have received significant attention because the architecture offers high spectral efficiency. However, relatively little research exists on optimization of SM systems in the presence of jamming. In a spatially uncoded SM system, such as V-BLAST, the channel state information is assumed to be unavailable a priori at both transmitter and receiver. Here, Kalman filtering is used to estimate the Rayleigh fading channel at the receiver. The spatial correlation of the jammer plus noise is also estimated, and spatial whitening to reject the jammers is employed in both the Kalman channel estimator and detector. To avoid the exponential complexity of maximum-likelihood (ML) detection, the QRD-M algorithm is employed. In contrast to sphere decoding, QRD-M has fixed decoding complexity of order O(M), and is thus attractive for hardware implementation. The performance of the joint Kalman filter channel estimator, spatial whitener and QRD-M detector is verfied by simulations.
    • Unscented Filter for OFDM Joint Frequency Offset and Channel Estimation

      Iltis, Ronald A.; University of California (International Foundation for Telemetering, 2006-10)
      OFDM is a preferred physical layer for an increasing number of telemetry and LAN applications. However, joint estimation of the multipath channel and frequency offset in OFDM remains a challenging problem. The Unscented Kalman Filter (UKF) is presented to solve the offset/channel tracking problem. The advantages of the UKF are that it is less susceptible to divergence than the EKF, and does not require computation of a Jacobian matrix. A hybrid analysis/simulation approach is developed to rapidly evaluate UKF performance in terms of symbol-error rate and channel/offset error for the 802.11a OFDM format.
    • Analytic Solutions for Optimal Training on Fading Channels

      Kosbar, Kurt; Panagos, Adam; University of Missouri (International Foundation for Telemetering, 2006-10)
      Wireless communication systems may use training signals for the receiver to learn the fading coefficients of the channel. Obtaining channel state information (CSI) at the receiver is often times necessary for the receiver to correctly detect and demodulate transmitted symbols. The type of training signal, the length of time to spend training, and the frequency of training are all important parameters in these types of systems. In this work, we derive an analytic expression for calculating the optimal training parameters for continuously fading channels. We also provide simulation results showing why this training scheme is considered optimal.
    • DESIGN AND CONSTRUCTION OF AN OPTICAL TELEMETRY SYSTEM

      Spjut, Erik; Kirkpatrick, Brian; Prounh, Chris; Rowland, Clarence; Ryckman, Raymond; Winton, Elizabeth; Harvey Mudd College (International Foundation for Telemetering, 2006-10)
      The Edwards Air Force Base Clinic team at Harvey Mudd College designed, built, and tested a prototype for a laser-based telemetry system. The test data were encoded on a 500 mW 1550 nm laser aimed at a ground station by a computer-controlled gimbal. The system communicated from a terrestrial vehicle to a ground station over a distance of 900 m. The extrapolated results indicate a maximum range of greater than 3000 m. This project emphasized COTS parts to minimize cost. Suggestions for the next-generation design, with an air-to-ground link, higher throughput, and greater range, are presented.