Reil, Michael J.; Bartlett, T. George; Henry, Kevin; SFA Inc.; Aberdeen Test Center; Sverdrup Technology Inc. (International Foundation for Telemetering, 2006-10)
      This paper is a follow on to a paper presented at the 2005 International Telemetry Conference by Dr. Samuel Harley et. al., titled Data, Information, and Knowledge Management. This paper will describe new techniques and provide further detail into the inner workings of the VISION (Versatile Information System – Integrated, Online) Engineering Performance Data Mart.

      Rice, Michael; Nelson, Tom; Brigham Young University (International Foundation for Telemetering, 2006-10)
      The optimum detector for shaped offset QPSK (SOQPSK) is a trellis detector which has high complexity (as measured by the number of detection filters and trellis states) due to the memory inherent in this modulation. In this paper we exploit the cross-correlated, trellis-coded, quadrature modulation (XTCQM) representation of SOQPSK-TG to formulate a reduced complexity detector. We show that a factor of 128 reduction in the number of trellis states of the detector can be achieved with a loss of only 0.2 dB in bit error rate performance as compared to optimum at P(b) = 10^(-5).

      Ferrill, Paul; Avionics Test and Analysis Corporation (International Foundation for Telemetering, 2006-10)
      As more aircraft are fitted with solid state memory recording systems, the need for a large data archival storage system becomes increasingly important. In addition, there is a need to keep classified and unclassified data separate but available to the aircrews for training and debriefing along with some type of system for cataloging and searching for specific missions. This paper will present a novel approach along with a reference design for using commercially available hardware and software and a minimal amount of custom programming to help address these issues.
    • Securing Print Services for Telemetry Post-Processing Applications

      Hines, Larry; Kalibjian, Jeff; Hewlett Packard Corporation (International Foundation for Telemetering, 2006-10)
      One of the primary goals of telemetry post processing is to format received data for review and analysis. This occurs by both displaying processed data on video monitors and by printing out the results to hardcopy media. Controlling access (i.e. viewing) of telemetry data in soft form (i.e. video monitor) is achieved by utilizing the existing framework of authentication and authorization on the client/server machines hosting the telemetry data (and post processing applications). Controlling access to hardcopy output has historically been much more problematic. This paper discusses how to implement secure printing services for telemetry post processing applications.

      Dean, Richard; Mwangi, Patricia A. W.; Haj-Omar, Amr; Montaque, Kishan; Morgan State University (International Foundation for Telemetering, 2006-10)
      The aeronautical channel is an air to ground channel characterized by multipath, high doppler shifts, Rayleigh fading and noise. Use of a channel sounder ensures proper estimation of the parameters associated with the impulse response of the channel. These estimates help us to characterize the radio channels associated with aeronautical telemetry. In order to have a satisfactory channel characterization, the amplitudes, phase shifts and delays associated with each multipath component in the channel model must be determined.
    • 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.

      Leite, Nelson Paiva Oliveira; Walter, Fernando; CTA - Grupo Especial de Ensaios em Vôo; ITA - Divisão de Telecomunicações (International Foundation for Telemetering, 2006-10)
      For the final evaluation of a GPS attitude determination algorithm, it was determined its true performance in terms of accuracy, reliability and dynamic response. To accomplish that, a flight test campaign was carried out to validate the attitude determination algorithm. In this phase, the measured aircraft attitude was compared to a reference attitude, to allow the determination of the errors. The system was built using non-dedicated airborne GPS receivers, and a complete Flight Tests Instrumentation (FTI) System. The flight test campaign was carried out at the Brazilian’s Flight Test Group T-25C 1956 Basic Trainer aircraft. The performance and accuracy of the system is demonstrated under static and dynamics tests profiles, which are fully compliant with the Federal Aviation Administration (FAA) Advisory Circular (AC) 25-7A. Dynamic response of the system is evaluated.

      Berdugo, Albert; Hildin, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      Airborne data acquisition systems have changed very little over the years. Their growth has primarily been in the area of digital filtering and the acquisition of new avionic busses. Communication between data acquisition units operating as a system still employs Time Division Multiplexing scheme. These schemes utilize command and data busses like CAIS and PCM. Although this approach is highly efficient, it has many drawbacks. These drawbacks have resulted in rigid system architecture, system bandwidth limitations, highly specialized recorders to acquire unique avionic busses that would otherwise overwhelm the system bandwidth, and unidirectional flow of data and control. This paper describes a network centric data acquisition system that is Ethernet based. Although Ethernet is known as an asynchronous bus, the paper will describe a deterministic time distribution over the bus per IEEE-1588 that allows the use of a packet network for airborne data acquisition. The acquisition unit within the network system is defined by its MIB (Management Information Base) and operates as a data source unit. Other network components may operate as a data sink unit, such as recorders, or as a data source and sink. The role of different units in the network system will be evaluated. The paper will also describe network gateways that allow the use of traditional PCM systems with a network-based system.
    • A Time Correlated Approach to Adaptable Digital Filtering

      Grossman, Hy; Pellarin, Steve; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      Signal conditioning is a critical element in all data telemetry systems. Data from all sensors must be band limited prior to digitization and transmission to prevent the potentially disastrous effects of aliasing. While the 6th order analog low-pass Butterworth filter has long been the de facto standard for data channel filtering, advances in digital signal processing techniques now provide a potentially better alternative. This paper describes the challenges in developing a flexible approach to adaptable data channel filtering using DSP techniques. Factors such as anti-alias filter requirements, time correlated sampling, decimation and filter delays will be discussed. Also discussed will be the implementation and relative merits and drawbacks of various symmetrical FIR and IIR filters. The discussion will be presented from an intuitive and practical perspective as much as possible.

      Hedricks, Michael J.; Sussex, Jeff; Streich, Ronald G.; Vandenberg AFB (International Foundation for Telemetering, 2006-10)
      The transition of PCM recording from analog to digital recorders was completed at many test ranges more than a decade ago as marked by delivery of data on S-VHS tape, CD-ROM, DVD, ZIP disc, JAZ disc, 8mm tape and DLT tape for low rate data and D-1 cassettes for high rate data. Data then quickly began distribution via the internet and other networks. Analog recorders have remained a necessary legacy for the long transition to convert from analog to digital (PCM) data transmission from the test vehicles. However, the new digital recorder capabilities have removed this requirement to convert the transmissions from the test vehicle. Analog signal and predetection recording on digital recorders has been successfully demonstrated at costs below the existing analog recorders. Application of new techniques in a methodical transition program to the new digital recorders has proven the many benefits of recording wider bandwidths with excellent repeatability. Repeatability issues are primarily in the very low error sources of the processing system because the major analog error sources of the analog tape recorders, analog time code readers, analog demodulators, etc have been greatly reduced. This paper provides test results of recording higher signal rates and bandwidths of the new programs and describes the techniques and implementation through procedures of the Western Range transition from analog to digital recorders. Surprising results show predetection and analog signal recording costs are nearly the same as PCM recording costs due to the price of deliverable media with respect to mission recording requirements.
    • Translation of L and S Band Tracking Assets to X Band High Dynamic Testing

      Winstead, Michael (International Foundation for Telemetering, 2006-10)
      Recent Constraints on the use of L and S band spectrum led to the search for additional Frequency Domain Bandwidth augmentation for test range telemetry needs. The ITU (International Telecommunications Union) approved X band region is listed as 7000 MHz to 8500 MHz for telemetry space applications. Bandwidth is available within this domain subject to the WARC (World Administrative Radio Consortium) approvals. This paper describes tests and presents results illustrating methodology that is available, and which can be used for conversion of S-band assets to the X band spectral region.

      Beard, Randal W.; Taylor, Clark N.; Bradley, Justin; Prall, Breton; Brigham Young University (International Foundation for Telemetering, 2006-10)
      Brigham Young University recently introduced a project for undergraduates in which a miniature unmanned aerial vehicle system is constructed. The system is capable of autonomous flight, takeoff, landing, and navigation through a planned path. In addition, through the use of video and telemetry collected by the vehicle, accurate geolocation of specified targets is performed. This paper outlines our approach and successes in facilitating this accomplishment at the undergraduate level.
    • 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.

      Morrison, Thomas M.; JT3, Edwards AFB (International Foundation for Telemetering, 2006-10)
      Telemetry data are usually collected for analysis at some later time and can be monitored to follow the progress of a test. In the case of an Air Data System the signals from the sensors are sent to a computer that calculates the air data parameters for use on multiple LabView-generated displays, as well as to the Data Acquisition System. The readouts on the multiple displays need to be real-time so they are useful to the flight crew. Equations that control the different air data values are determined by what telemetry data are available and the preference of those doing the test planning. These systems need to display the information in a format useful to the flight crew and be reliable.

      Pillai, Sreelal Sreedharan; Sankarattil, Sreekumar; Padmanabhan, Padma; Rao, Vinod Padmanabha; Pillai, Sivasubramonia; Pillai, Madaswamy; Kollamparambil, Damodaran; Kurian, Thomas; Thirunavukkarasu, Chidambaram; Indian Space Research Organization (International Foundation for Telemetering, 2006-10)
      We describe the design and development of a baseband telemetry system for multistage launch vehicles. The system is organized as a three tier one with remote data acquisition and processing units and a centralized control unit. The front-end Data Acquisition Units (DAUs) feature software programmable amplification, offset, filtering and sensor excitation and thus are flexible to interface directly to a variety of sensors used in launch vehicles. The Data Processing Units (DPUs) gather data from DAUs through a serial link compatible to RS-485 standards and carry out a variety of data analysis and data compression functions on selected channels under software control. The central Telemetry Control Unit (TCU) receives this data through a transformer isolated link compatible to MIL-1553B standards and performs the functions of data delay, data storage, onboard computer data monitoring, PCM formatting and pre-modulation signal conditioning to achieve miniaturization. The configuration and features of this telemetry system make its integration simple without compromising on data integrity and reliability and suit the adoption of futuristic technologies and concepts such as smart sensor networks, adaptability, reconfiguration and vehicle health management.

      Xiangwu, Gao; Juan, Lin; Zhengguang, He; Beijing Institute of Astronautical Systems Engineering; China Academy of Launch Vehicle Technology (International Foundation for Telemetering, 2006-10)
      XX launch vehicle has been flying onboard video system which includes video cameras, data compression devices and channel switch device for the second Chinese spaceflight. The camera is a PAL analog camera that been sampled and compressed by compression device. The compressed digital video data is combined with telemetry data into the telemetry radio channel. Lighting is provided by sunlight, or a light has been equipped when sunlight is unavailable. IRIG-B timing is used to correlate the video with other vehicle telemetry. The video system’s influences to the vehicle flight have been decreased to minimum.

      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.

      Chaildin, Mark; Inter-Coastal Electronics (International Foundation for Telemetering, 2006-10)
      For several decades, the military has used the Multiple Integrated Laser Engagement System (MILES) with a series of iR sensors along a belt fastened to a vehicle for training and simulation. Now, an alternative to this legacy system, a solar rechargeable battery powered wireless IR sensor is replacing wired sensors. The use of short-range RF communications network, allows the MILES sensors strategic placement about a combat vehicle without the umbilical cabling normally required for power and signal coupling from the players processing unit. The RF network operates in the 340 to 380 MHz band, has channeling capability of over 1600 channels, and coexists with the vehicles on board high-powered radios without interference. The wireless sensor implements a custom designed IR sensing amplifier, designed for maximum sensitivity and minimal power dissipation, along with advanced semiconductor IC’s for signal processing and power conversion. Solar recharging enables the sensor to operate for extended time, on a single battery that should last for years without replacement. A proprietary software protocol, developed for communication integrity, is a critical part of the overall system and supports other sensor types and control elements with low data rates for a wireless Vehicle Area Network. The system, successfully installed on several military training platforms, proves to be a viable product for military training and simulation systems for the 21st century.
    • Wireless Sensor System for Airborne Applications

      Berdugo, Albert; Grossman, Hy; Schofield, Nicole; Musteric, Steven; Teletronics Technology Corporation; Eglin Air Force Base (International Foundation for Telemetering, 2006-10)
      Adding an instrumentation / telemetry system to a test vehicle has historically required an intrusive installation for wiring and powering all elements of the system from the sensor to the telemetry transmitter. In some applications there is need for a flexible and modular instrumentation and telemetry system that can be installed with minimal intrusiveness on an aircraft without the need for permanent modifications. Such an application may benefit from the use of a miniaturized, inexpensive network of wireless sensors. This network will communicate its data to a central unit installed within the aircraft. This paper describes recent efforts associated with the Advanced Subminiature Telemetry System (ASMT) Initial Test Capability Project. It discusses the challenges in developing a wireless sensor network system for use in an airborne environment. These include selection of frequencies, COTS wireless devices, batteries, system synchronization, data bandwidth calculations, and mechanical structure for external installation. The paper will also describe the wireless network architecture as well as the architecture of the wireless sensor and the central control unit.