• Helicopter Slip Ring Replacement System

      Adamson, Alan; Berdugo, Albert; Flight Test Instrumentation; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      Most helicopter programs require the acquisition of parameters from the rotating systems. Historically, these systems made use of electromechanical slip rings for the transfer of power, control, and data from within the helicopter's cabin to the rotating hardware. Slip rings are primarily used in dedicated instrumentation vehicles and are not commonly used in production platforms that may require instrumentation of the rotating systems for in-service load and fatigue monitoring. Additionally, the use of slip rings requires time and money to integrate the hardware and equipment into the aircraft in order to perform rotor data acquisition. The time needed to perform modifications to transmissions and drive trains plays a big factor in the increased costs of aircraft development. Less intrusive installations would minimize the need for mechanical changes and would improve the time needed to install the instrumentation. This paper describes a wireless system approach to perform the test without the slip ring, and provides performance data that validates this new method of instrumenting unobtrusively to save time and money without sacrificing data integrity.
    • FTI Network Discover, Health, and Status Monitoring

      Cranley, Nikki; ACRA Control (International Foundation for Telemetering, 2010-10)
    • Bulk Creation of Data Acquisition Parameters

      Kupferschmidt, Benjamin; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      Modern data acquisition systems can be very time consuming to configure. The most time consuming aspect of configuring a data acquisition system is defining the measurements that the system will collect. Each measurement has to be uniquely identified in the system and the system needs to know what data the measurement will sample. Data acquisition systems are capable of sampling thousands of measurements in a single test flight. If all of the measurements are created by hand, it can take many hours to input all of the required measurements into the data acquisition system's setup software. This process can also be extremely tedious since many measurements are very similar. This paper will examine several possible solutions to the problem of rapidly creating large numbers of data acquisition measurements. If the list of measurements that need to be created already exists in an electronic format then the simplest approach would be to create an importer. The two main ways to import data are XML and comma separated value files. This paper will discuss the advantages and disadvantages of both approaches. In addition to importers, this paper will discuss a system that can be used to create large numbers of similar measurements very quickly. This system is ideally suited to MILSTD- 1553 and ARINC-429 bus data. It exploits the fact that most bus measurements are typically very similar to each other. For example, 1553 measurements typically differ only in terms of the command word and the selected data words. This system allows the user to specify ranges of data words for each command word. It can then create the measurements based on the user specified ranges.
    • Modular Field Programmable Gate Array Implementation of a MIMO Transmitter

      Kosbar, Kurt; Shekhar, Richa; Missouri University of Science and Technology (International Foundation for Telemetering, 2010-10)
      Multiple-Input Multiple-Output (MIMO) systems have at least two transmitting antennas, each generating unique signals. However some applications may require three, four, or more transmitting devices to achieve the desired system performance. This paper describes the design of a scalable MIMO transmitter, based on field programmable gate array (FPGA) technology. Each module contains a FPGA, and associated digital-to-analog converters, I/Q modulators, and RF amplifiers needed to power one of the MIMO transmitters. The system was designed to handle up to a 10 Mbps data rate, and transmit signals in the unlicensed 2.4 GHz ISM band.
    • Decoding and Turbo Equalization for LDPC Codes Based on Nonlinear Programming

      Iltis, Ronald A.; University of California, Santa Barbara (International Foundation for Telemetering, 2010-10)
      Decoding and Turbo Equalization (TEQ) algorithms based on the Sum-Product Algorithm (SPA) are well established for LDPC codes. However there is increasing interest in linear and nonlinear programming (NLP)-based decoders which may offer computational and performance advantages over the SPA. We present NLP decoders and Turbo equalizers based on an Augmented Lagrangian formulation of the decoding problem. The decoders update estimates of both the Lagrange multipliers and transmitted codeword while solving an approximate quadratic programming problem. Simulation results show that the NLP decoder performance is intermediate between the SPA and bit-flipping algorithms. The NLP may thus be attractive in some applications as it eliminates the tanh/atanh computations in the SPA.
    • Low-Complexity Finite Precision Decoders for Low-Density Parity-Check Codes

      Vasic, Bane; Declercq, David; Marcellin, Michael W.; Planjery, Shiva Kumar; University of Arizona (International Foundation for Telemetering, 2010-10)
      We present a new class of finite-precision decoders for low-density parity-check (LDPC) codes. These decoders are much lower in complexity compared to conventional floating-point decoders such as the belief propagation (BP) decoder, but they have the potential to outperform BP. The messages utilized by the decoders assume values (or levels) from a finite discrete set. We discuss the implementation aspects as well as describe the underlying philosophy in designing these decoders. We also provide results to show that in some cases, only 3 bits are required in the proposed decoders to outperform floating-point BP.
    • Localization Using CDMA-MIMO Radar

      Iltis, Ronald A.; University of California, Santa Barbara (International Foundation for Telemetering, 2010-10)
      A MIMO radar system for target localization is presented which uses direct-sequence CDMA (DS-CDMA) waveforms. The received DS-CDMA signal at each antenna is expressed directly in terms of the target positions. The waveforms employed are Gold sequences, and hence are not exactly orthogonal. A generalized successive interference cancellation (GSIC) approach is used to resolve multiple scatterers and reduce clutter. Simulation results are presented which suggest the capability to detect weak scatterers in the presence of clutter using the cancellation method.
    • Novel Angle of Arrival Algorithm for Use in Acoustical Positioning Systems with Non Uniform Receiver Arrays

      Lee, Hua; Utley, Christopher; University of California, Santa Barbara (International Foundation for Telemetering, 2010-10)
      Traditional angle of arrival algorithms operate with uniform receiver arrays. Non-uniform arrays typically introduce significant elevation of computation complexity. This paper utilizes the double-integration method for the accurate estimation of the angle of arrival with non-uniform receiver arrays, while maintaining high computation efficiency. Because of the simplicity, the double-integration method is not significantly affected by the increase of the number of receivers or the non-uniform configuration. This approach allows us to perform high-speed high-accuracy estimation of the two-dimensional bearing angle without the constraints of structured receiver arrays, which is important to the realization of real-time tracking of mobile acoustic sources.
    • Channel Equalization and Spatial Diversity for Aeronautical Telemetry Applications

      Saquib, M.; Williams, Ian E.; University of Texas at Dallas (International Foundation for Telemetering, 2010-10)
      This work explores aeronautical telemetry communication performance with the SOQPSK- TG ARTM waveforms when frequency-selective multipath corrupts received information symbols. A multi-antenna equalization scheme is presented where each antenna's unique multipath channel is equalized using a pilot-aided optimal linear minimum mean-square error filter. Following independent channel equalization, a maximal ratio combining technique is used to generate a single receiver output for detection. This multi-antenna equalization process is shown to improve detection performance over maximal ratio combining alone.
    • Introduction to XidML 3.0 An Open XML Standard for Flight Test Instrumentation Description

      Cooke, Alan; Herbepin, Christian; ACRA Control; Eurocopter (International Foundation for Telemetering, 2010-10)
      A few years ago XidML was introduced as an open XML standard for capturing the meta-data associated with flight test instrumentation (FTI). This meta-data schema was broken down into elements for Parameter (name, range, units, offset-binary), Instrument (name, serial number, misses-to loss), Package (bits per word, words per minor-frame, rate) and Link (name, type) and so on. XidML remains one of the only published schema for FTI meta-data and with XidML 3.0 many simplifications have been introduced along with support for nested tree structures and a single instrument schema allowing anyone to define the validation for instruments from any vendor. This paper introduces the XidML schema and describers the benefits of XidML 3.0 in particular. It begins by giving a brief description of what XidML is and describes its history and motivation. The paper then outlines the main differences between XidML-3.0 and earlier versions, and how the XidML schema has been further refined to meet the challenges faced by the FTI community. As an example of usage the FTIManager software developed at Eurocopter will be briefly presented in order to illustrate the XidML ability to describe a multi-vendor FTI configuration.
    • Verification, Validation and Completeness Support for Metadata Traceability

      Darr, Timothy; Fernandes, Ronald; Hamilton, John; Jones, Charles; Knowledge Based Systems, Inc.; Edwards Air Force Base (International Foundation for Telemetering, 2010-10)
      The complexity of modern test and evaluation (T&E) processes has resulted in an explosion of the quantity and diversity of metadata used to describe end-to-end T&E processes. Ideally, it would be possible to integrate metadata in such a way that disparate systems can seamlessly access the metadata and easily interoperate with other systems. Unfortunately, there are several barriers to achieving this goal: metadata is often designed for use with specific tools or specific purposes; metadata exists in a variety of formats (legacy, non-legacy, structured and unstructured metadata); and the same information is represented in multiple ways across different metadata formats.
    • A Low Cost, Quick Reaction TM Acquisition System Solution for Deployed Testing

      Pozmantier, Ronald; Edwards Air Force Base (International Foundation for Telemetering, 2010-10)
      Design, development, fabrication, and deployment of an austere, deployable telemetry (TM) system, in only 3 1/2 weeks, will be discussed. This austere approach will be compared to a standard approach. TM candidate systems will be discussed along with exigencies and limitations (test geometry, link analysis, multiple test areas, schedule, cost, fabrication ...) that shaped their selection. Utilization of existing Radio Frequency (RF) systems in "unintended" applications will be discussed. System setup and BER testing with a simulated 'aircraft' will be presented, including observed multipath effects during testing, versus actual performance. Finally, benefits and test efficiencies garnered by having vehicle TM, real- time TM acquisition, processing and display, while deployed to a test area with no range instrumentation, will be presented.
    • X-Tools: A Case Study in Building World Class Software

      Cooke, Alan; ACRA Control (International Foundation for Telemetering, 2010-10)
      X-Tools is a collection of utilities for validation, translation, editing and report generation designed to enable the Flight Test Instrumentation (FTI) community to quickly adopt the XidML 3.0 meta-data standard. This paper discusses the challenges of developing such software that meets the current and future needs of the FTI community, and meets the increasingly high quality standards expected of modern software. The paper first starts by discussing the needs of the FTI community and the specific functional requirements of software. These include the ability to fit in with legacy systems, the ability to handle many tens of thousands of parameters, support for new networked-based technologies and support for hardware from any vendor. The non-functional requirements of FTI orientated software are also described and it is suggested that the key non-functional requirements include testability, modifiability, extensibility and maintainability. Finally, as a case study, the X-Tools from ACRA CONTROL are presented. The paper discusses their design, and the tactics used to meet the functional and non-functional requirements of the FTI industry. The paper then outlines how the rigorous quality standards were met and describes the specific mechanisms used to verify the quality of the software.
    • Accessing Chapter 10 Recorder Media from Windows PCs

      Kupferschmidt, Benjamin; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      The RCC IRIG Chapter 10 standard requires that Chapter 10 recorders use the STANAG- 4575 (NATO Advanced Data Storage Interface) file system to store data files. The STANAG-4575 standard defines a linear file system in which each file is stored in a single contiguous block of disk space. There is a small directory listing at the beginning of the disk. This listing stores the starting position and length for each file. It also stores the file's name and its creation date and time. This file system is very efficient for storing files that are recorded sequentially because it does not require the disk to constantly update a file allocation table on each write. Unfortunately, the STANAG-4575 file system is not directly supported by Microsoft Windows. This means that it is not possible to simply attach a recorder's disk to a PC and copy the files directly using Windows Explorer. This paper will discuss an approach that allows the contents of a STANAG formatted disk to be read from a standard Windows PC. In addition to copying files from the disk, this approach allows several other useful operations to be performed on the disk. These operations include advanced copy options such as partial file copies and splitting files into multiple pieces. It can also provide a mechanism for deleting files, reformatting the disk and performing a sanitization procedure on a disk to declassify it.
    • A Robotic Platform for Student System Design

      Kosbar, Kurt; Rodhouse, Kathryn; Ziegler, Steven; Huttsell, Ryan; Missouri University of Science and Technology (International Foundation for Telemetering, 2010-10)
      The goal of the project described in this paper, is to develop a platform for undergraduate engineering students to use in system analysis and design courses. We chose to develop an inexpensive robotic platform. The robot is intended to be autonomous, under the control of an on-board microcontroller. In the first revision of the hardware, a three wheeled design will be used, with the intention of being used indoors, on smooth surfaces. Students in their first year of college education will purchase the components, and assemble the robot. After analyzing the baseline design, they will be encouraged to incorporate new sensors and actuators in the subsequent laboratory courses.
    • Integrity Analysis and Fault Detection of Flight Test Data

      Glenn, Gregory J.; Duong, Nhattrieu; Speyer, Jason L.; Sysense, Inc. (International Foundation for Telemetering, 2010-10)
      Undetected sensor malfunctions during flight testing can lead to cost overruns and program delays. Determining the presence of these faults in a timely manner allows the operator to mitigate their effect. One way to detect these faults is to use a priori knowledge of sensor calibration data and system dynamics to calculate measurement uncertainties. These can then be used to determine the integrity of the sensor data and report violations of expected sensor behavior. Analytical redundancy methods and residual processing can be used in conjunction with a priori sensor information to detect faults otherwise unobserved with single-instrument data as well as to isolate and identify failure modes. These simulation and analysis methods have been implemented as MATLAB® Simulink® blocks and were used to model the flight instruments, detect anomalies in the navigation instruments, and locate the origin of the errors of a flight test data set.
    • An Integrated Data Acquisition System for Parachute Development and Qualification Testing

      Starbuck, Philip; PSG and Associates (International Foundation for Telemetering, 2010-10)
      The development and qualification of personnel and cargo aerial delivery parachute systems present unique challenges to the instrumentation and data analysis engineers. Some of the areas that must be addressed include: a) system must be low in cost, b) system often has to be operated on ranges that have limited telemetry or other range instrumentation and support (i.e. commercial skydiving centers), c) system is often rigged and operated by parachute support personnel and test jumpers rather than instrumentation engineers, and d) system must be able to be reconfigured in the field to support a variety of test card requirements during a typical test day, e) data must be available for review and the system be prepared for the next test within a few minutes of parachute recovery, and f) system must withstand ground impact velocities as high as 50 ft/sec (15.24 m/sec) without damage. This paper describes such a system as it is being used for the development and qualification testing of a number of parachute systems for sport skydiving, military personnel, as well as cargo parachute systems. This modular system has been developed as a result of previous experience in other parachute development and qualification projects to address the need for a flexible Data Acquisition System (DAS) system that meets the above requirements. This paper describes some of the tools used to meet these requirements.
    • Multi-Band (L/S/C) Nested Concentric Cavity Coaxial Mode RF Feed for Autotrack Telemetry Systems

      Blake, George R.; Shea, Don F.; Hoory, Yossi; Krepner, Itzik; Pein, Joe; Nahshon, Ofir; Orbit Communications Systems (International Foundation for Telemetering, 2010-10)
      Recognizing the current and future requirements of extending Telemetry, TT&C, Earth Resources operations into the C-Band (4400-5200 MHZ) arena, Orbit Communication Systems and Orbit Communication Ltd. are currently designing and testing a Tri-Band auto-tracking / receive / transmit feed technology combining dual polarization with multiple frequency band coverage (L/S/C) into a single feed that can be fitted onto new or existing antenna systems. This technology reduces footprint and minimizes life cycle cost, both of which are important considerations for both our commercial and military customers. This technology has been applied to a number of systems, including flyaway, fixed (or teleport) and shipboard, and is readily applicable to ground and mobile applications. The multiband feed design consists of coaxial, concentric waveguide cavities operating in TE11 and TE21 modes (Patent Pending). The large outermost cavities of the feed operate in the L/S frequency band while the innermost cavities operate at C-Band. The antenna is fed with orthogonally polarized inputs/outputs enabling polarization diversity in all bands. The coaxial cavity feed is ideal for this application because the feed produces high-efficiency, near-optimum illumination patterns and coincident phase centers in all three bands simultaneously. Because it is a waveguide design, the input power levels used in Telemetry and Satellite systems do not present breakdown problems. This type of feed has proved to be an ideal multiband illuminator for parabolic reflectors, and therefore could be used in many military and commercial applications that require multiband operation.
    • The Design of an Application Used for Aircraft Stability Evaluation

      Leite, Nelson Paiva Oliveira; Lopes, Leonardo Mauricio de Faria; Walter, Fernando; Grupo Especial de Ensaios em Vôo; Instituto Tecnológico de Aeronáutica (International Foundation for Telemetering, 2010-10)
      One of the most important characteristics of an aircraft is its capability to return to its stable trimmed flight state after the occurrence of a disturbance or gust without the pilot intervention. The evaluation of such behavior, known as the aircraft stability, is divided into three sections: Lateral; Directional; and Longitudinal stabilities. The determination of the stability of an experimental aircraft requires the execution of a Flight Test Campaign (FTC). For the stability FTC the test bed should be equipped with a complete Flight Test Instrumentation (FTI) System which is typically composed by: a Pulse Code Modulation (PCM) Data Acquisition System (DAS); A sensor set; An airborne transmitter; and A data recorder. In the real-time operations, live data received over the Telemetry Link, that are processed, distributed and displayed at the Ground Telemetry System (GTS) enhances the FTC safety level and efficiency. The due to the lack of reliability, recorded data is retrieved in the post mission operations to allow the execution of data reduction analysis. This process is time consuming because recorded data has to be downloaded, converted to Engineering Units (EU), sliced, filtered and processed. The reason for the usage of this less efficient process relies in the fact that the real-time Telemetry data is less reliable as compared to recorded data (i.e. noisier). The upcoming iNET technology could provide a very reliable Telemetry Link. Therefore the data reduction analysis can be executed with live telemetry data in quasi-real time after the receipt of all valid tests points. In this sense the Brazilian Flight Test Group (GEEV) along with EMBRAER and with the support of Financiadora de Estudos e Projetos (FINEP) started the development of several applications. This paper presents the design of a tool used in the Longitudinal Static Stability Flight Tests Campaign. The application receives the Telemetry data over either a TCP/IP or a SCRAMnet Network, performs data analysis and test point validation in real time and when all points are gathered it performs the data reduction analysis and automatically creates Hyper Terminal Markup Language (HTML) formatted tests reports. The tool evaluation was executed with the instruction flights for the 2009 Brazilian Flight Test School (CEV). The result shows an efficiency gain for the overall FTC.
    • Performance Comparison of Aeronautical Telemetry in S-Band and C-Band

      Temple, Kip; Selbrede, Robert; Edwards Air Force Base (International Foundation for Telemetering, 2010-10)
      This paper compares telemetry link performance of the PCM/FM waveform when simultaneously transmitting in two different frequency bands, S-Band and C-Band. A description of the aircraft and ground station is presented followed by flight test results. These results are presented in the form of received signal strength and accumulated bit errors, versus time and link availability, over the flight paths. Conclusions are drawn based upon the presented flight test results.