• Decision Feedback Equalization for SOQPSK

      Rice, Michael; Narumanchi, Gayatri; Saquib, Mohammad; Brigham Young University; University of Texas at Dallas (International Foundation for Telemetering, 2012-10)
      This paper investigates a fractionally-spaced decision-feedback equalization technique for Shaped Offset Quadrature Phase Shift Keying (SOQPSK). The kernel of the block-based feedback algorithm is to estimate the intersymbol interference and cancel it from the samples used to make the bit decisions. This process refines the bit estimates sequentially, thereby increasing the probability of obtaining accurate estimates. The simulated bit error rate performance of the decision-feedback technique shows a 1 dB improvement over MMSE-equalized SOQPSK-TG over channels derived from multipath channel measurements at Cairns Army Airfield, Ft. Rucker, Alabama and Edwards AFB, California.
    • Delay Spread Characterization of the Aeronautical Channel

      Fofanah, Ibrahim; Assegu, Wannaw; Morgan State University (International Foundation for Telemetering, 2012-10)
      Radio transmission channel influences greatly the quality of transmitted voice and data signal in terms of data rate and robustness. This degradation is as a result of many factors, notable amongst them are having multiple replica of the transmitted signal at the receiver (multipath), changes of frequency as a result of the movement of the aircraft (Doppler shift) and noise. This paper characterizes the scattered components of the aeronautical channel in terms of delay spread. Geometric representation is used to derive expressions for the maximum delay spread using the 2-ray model and the three dimensional model of the scattered path. Furthermore, the delay and Doppler frequencies are described as a function of the horizontal distance to the specular reflection point between a ground station and a test article. The simulated results are compared to measured data of related articles and the value of the maximum delay spread is compared with the proposed intersymbol guard band for Orthogonal Frequency Division Multiplexing (OFDM) in the Integrated Network Enhanced Telemetry (iNET) program to see if this proposition can be adapted to the aeronautical channel.
    • Design and Implementation of the Next Generation Landsat Satellite Communications System

      Mah, Grant; O'Brien, Mike; Garon, Howard; Mott, Claire; Ames, Alan; Dearth, Ken; United States Geological Survey (USGS) Earth Resource Observations and Science (EROS) Center; Stinger Ghaffarian Technologies (SGT, Inc.); Muniz; Orbital Sciences Corporation; et al. (International Foundation for Telemetering, 2012-10)
      The next generation Landsat satellite, Landsat 8 (L8), also known as the Landsat Data Continuity Mission (LDCM), uses a highly spectrally efficient modulation and data formatting approach to provide large amounts of downlink (D/L) bandwidth in a limited X-Band spectrum allocation. In addition to purely data throughput and bandwidth considerations, there were a number of additional constraints based on operational considerations for prevention of interference with the NASA Deep-Space Network (DSN) band just above the L8 D/L band, minimization of jitter contributions to prevent impacts to instrument performance, and the need to provide an interface to the Landsat International Cooperator (IC) community. A series of trade studies were conducted to consider either X- or Ka-Band, modulation type, and antenna coverage type, prior to the release of the request for proposal (RFP) for the spacecraft. Through use of the spectrally efficient rate-7/8 Low-Density Parity-Check error-correction coding and novel filtering, an XBand frequency plan was developed that balances all the constraints and considerations, while providing world-class link performance, fitting 384 Mbits/sec of data into the 375 MHz X-Band allocation with bit-error rates better than 10⁻¹² using an earth-coverage antenna.
    • Design Improvement and Implementation of 3D Gauss-Markov Mobility Model

      Alenazi, Mohammed J. F.; Sahin, Cenk; University of Kansas (International Foundation for Telemetering, 2012-10)
      The current ns-3 implementation of the 3D Gauss-Markov mobility model (3D-GMMM) allows mobile nodes to reach and bounce off the simulation boundaries. This causes sudden and unnatural movement of the nodes in the vicinity of the simulation boundaries. In this paper, we present a modification to the current ns-3 implementation of the 3D-GMMM. We follow an approach in which mobile nodes are directed toward the center of the simulation region at a random angle if they are within a certain distance from the simulation boundaries. As the simulation results show, the improved ns-3 implementation of 3D-GMMM prevents mobile nodes from reaching the simulation boundaries while resulting in smooth movement.
    • The Design of a Fully Autonomous RC Racecar

      Archibald, James K.; Wilde, Doran; Rice, Michael D.; Black, Richard A.; Brigham Young University (International Foundation for Telemetering, 2012-10)
      This paper discusses the design of an autonomous remote-controlled racecar to play a one-on-one match of capture the flag. A competition was held, and the results are presented and conclusions are made.
    • Design of a Radio channel Simulator for Aeronautical Communications

      Montaquila, Roberto V.; Iudice, Ivan; Castrillo, Vittorio U.; C.I.R.A. (International Foundation for Telemetering, 2012-10)
      The goal of this paper is to implement a model of multipath fading in a radio channel simulator for aeronautical applications. When developing a wireless communications system, it is useful to perform simulations of the radio context in which the system has to operate. A radio link is substantially composed by three parts: transmitting segment, transmission channel and receiving segment. We focus our attention on the radio channel propagation. We proposed two geometrical models of a territory corresponding to a determined flight area and, after importing the data needed to estimate our parameters, we compared our results with the channel soundings in literature, obtaining comparable values.
    • Design of a Semi-Autonomous Quadrotor Aircraft

      Kosbar, Kurt; Hickle, Mark; Wilson, Alexander; Kientzy, Joshua; Myers, Matthew; Missouri University of Science and Technology (International Foundation for Telemetering, 2012-10)
      This paper describes the design and construction of a semi-autonomous quadrotor aircraft approximately 1 meter in diameter. Because of the mechanical simplicity of the aircraft, the design challenges primarily centered on the electrical and computer engineering (ECE) tasks, and was used as a capstone design experience in an undergraduate ECE program. An onboard microcontroller based system uses a network of digital sensors and differential thrust for autonomous attitude control. A wireless telemetry and command link allows a user to monitor the vehicle, control its direction of flight, and for flight safety control.
    • Design of Basic Receiving Functions for an SDR Based Communication System

      Manco, Angelo; Castrillo, Vittorio U.; C.I.R.A. (International Foundation for Telemetering, 2012-10)
      The paper focuses on the design and implementation of the base-band basic receiving functions, for a binary CP-FSK demodulator pilot study, as independent modules of a complete Reconfigurable Data-Link (RDL). A model-based approach and Software Defined Radio (SDR) paradigm are used for the design. The implementation will be executed on Field-Programmable Gate Array (FPGA) based hardware.
    • The Design of Dynamic Calibration Procedure

      Leite, Nelson Paiva Oliveira; Sousa, Lucas Benedito dos Reis; Instituto de Pesquisas e Ensaios em Voo (International Foundation for Telemetering, 2012-10)
      The execution of experimental Flight Test Campaign (FTC) provides all information required for the aircraft operation and certification. Nowadays all information gathered during a FTC is provided by the Flight Test Instrumentation System (FTI) that is basically a measurement system. Typically for all FTI parameters, the estimation of the calibration coefficients that minimizes most of systematic errors and its associated uncertainty is carried out by a Static Calibration Process. To execute this task the Brazilian Institute of Research and Flight Test (Instituto de Pesquisa e Ensaios em Voo - IPEV) developed the Sistema de Automação do Laboratório de Ensaios em Voo (SALEV©) which is fully compliant with the calibration and uncertainty expression standards. For some parameters (i.e. Static Pressure) the sensor installation particularities (i.e. Pressure tapping) introduces low pass filtering characteristics into the measurement chain. In this case the measurement accuracy will be jeopardized when executing high-dynamic test points (i.e. Spin Tests). To overcome this issue the IPEV research and development group introduced a dynamic calibration process for flight test parameters that requires the knowledge of the actual Transfer Function (TF). The problem now is to simulate an impulsive input for the TF characterization which is too complex. To solve this issue a new calibration procedure was developed and evaluated for the determination of the FTI dynamic response. SALEV© was used to simulate a step input instead of an impulse. Then filtered and unfiltered data was properly compared for the determination of the TF. Preliminary test results show satisfactory performance.
    • Development of a Variable Output Power, High Efficiency Programmable Telemetry Transmitter Using GaN Amplifier Technology

      Oder, Stephen; Arinello, Paula; Caron, Peter; Crawford, Scott; McGoldrick, Stephen; Bajgot, Douglas; Cobham Electronic Systems (International Foundation for Telemetering, 2012-10)
      Cobham Electronic Systems, Inc. has developed a field-programmable telemetry transmitter module for higher-power (0.1W to 25W) airborne telemetry applications. A key feature of the transmitter is high DC to RF conversion efficiency over the entire variable output power range of 25dB through the use of GaN amplifiers. This high efficiency is realized by using a variable voltage DC-DC converter and dynamic bias control of the GaN amplifier elements. This feature is useful in that output power can be tailored to mission requirements and timelines, thereby extending battery life and increasing operation time. The transmitter receives configuration commands and can be programmed through an external data port. The transmitter can be configured for RF power and frequency over the telemetry S-Band frequency range, and has multiple data rates. The unit consists of RF, digital and power supply circuits. The RF transmitter is a PCM-FM type with a phase-locked loop, driver amplifiers, a power amplifier and a digital processor for RF control. The unit contains a digital processor, FPGA's, and flash memory. The power supplies contains all the regulator circuits to supply power to the rest of the unit, variable output drain voltage to the GaN devices, EMI filtering, under/overvoltage protection, a temperature sensor and a digital processor for power control. The electronics are housed in a compact aluminum housing.
    • Digital Radio Implementation for NASA S-Band Space Network Transceiver

      Thompson, Willie L.; Berhanu, Samuel; Neupane, Kamal; Morgan State University (International Foundation for Telemetering, 2012-10)
      The system diagrams for the digital radio compatible with NASA's S-Band Space Network operating from 2025.8 - 2117.9 MHz (forward link) to 2200 - 2300 MHz (return link) are presented. The digital radio implementation includes binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) and staggered quadrature phase shift keying (SQPSK). We have derived the system requirements for these modulation schemes from the Space Network User Guide (SNUG) and thereafter, derived system diagrams for the communication links. The designed system diagrams for the transceiver were implemented using Simulink models and USRP2 platform.
    • Discrete-Time Channelizers for Aeronautical Telemetry: Part I - Fixed Bandwidth

      Swenson, Brian; Rice, Michael; Brigham Young University (International Foundation for Telemetering, 2012-10)
      A discrete-time channelizer based on a polyphase filter bank and suitable for use with aeronautical telemetry is described. The discrete-time approach reduces the number of continuous-time components - and the need to maintain and calibrate these components. Channel selection is accomplished by changing a single parameter that defines a small part of the system.
    • Discrete-Time Channelizers for Aeronautical Telemetry: Part II - Variable Bandwidth

      Swenson, Brian; Rice, Michael; Brigham Young University (International Foundation for Telemetering, 2012-10)
      A discrete-time channelizer capable of variable bandwidth operation and suitable for use in aeronautical telemetry is described. The channelizer is based on the polyphase filterbank implementation and is capable of selecting bandwidths that are odd multiples of 1 MHz. The discrete-time approach reduces the number of continuous-time components and the need the maintain and calibrate these components.
    • DTN Gateway Architecture for Partially Disconnected Telemetry Environments

      Rohrer, Justin; Xie, Geoffrey G.; Naval Postgraduate School (International Foundation for Telemetering, 2012-10)
      Telemetry networks often operate in challenged wireless environments, resulting in periods of disconnection. Our delay tolerant networking (DTN) gateway dynamically detects disruptions in connectivity and buffers telemetry data until connectivity is reestablished. When the connection is resumed, all buffered data is transmitted automatically in order to backfill any gaps in the telemetry stream. A DTN gateway may operate as a standalone device with multiple DTN client applications, or as a network of mobile DTN gateways which will perform multi-hop ad-hoc routing to deliver telemetry data across the telemetry network system (TmNS). Our DTN gateway also provides conventional IP routing and forwarding capabilities, including support for standard dynamic routing protocols, eliminating the need for a stand-alone IP router on the test article (TA). This paper presents the system architecture of our DTN gateway, along with several deployment scenarios for telemetry environments.
    • EELV Incorporates GPS Metric Tracking as a Range Tracking Source

      Broadus, Charles; Siegal, Richard; Kreng, Jack; Moore, Theodore; United Launch Alliance; Microwave Innovations; The Aerospace Corporation (International Foundation for Telemetering, 2012-10)
      Currently, the Evolved Expendable Launch Vehicle (EELV) utilizes a communications, tracking, and control system that was developed at the inception of the space launch industry. The current system operation and large ground footprint have driven the United States Air Force (USAF) to embark on an initiative known as the Future Flight Safety System (FFSS) that will lead into a Space Based Range Concept. An important phase of FFSS is the implementation of Global Positioning System Metric Tracking (GPS MT) on all launch vehicles. Working in partnership, United Launch Alliance (ULA) and their USAF EELV customer have developed a common GPS MT solution for both the Atlas V and Delta IV Launch Vehicles.
    • Estimation and Correction of Quadrature-Receiver Phase Errors of Stepped-Frequency FMCW Systems for High-Resolution Imaging

      Liebling, Michael; Lee, Hua; Lee, Michael; Doonan, Daniel; University of California, Santa Barbara (International Foundation for Telemetering, 2012-10)
      This paper presents an algorithm for the reduction or removal of the quadrature-receiver phase errors of stepped-frequency frequency-modulated continuous wave (FMCW) imaging systems. The algorithm includes the procedures for the phase error estimation and correction process. Theoretical analysis and simulations are included in the paper to demonstrate the effectiveness of the algorithm.
    • Experimental Investigation of Wireless Technologies for Data Acquisition

      Cranley, Nikki; Curtiss-Wright Controls Avionics & Electronics (International Foundation for Telemetering, 2012-10)
      Now, more than ever, there is significant demand to reduce the weight of Flight Test Instrumentation (FTI) which in turn translates to cost savings. Moreover, there is the on-going requirement to improve the ease of installation, simplify wiring, and reduce power. Wireless technologies provide the ideal solution to overcome these issues by effectively eliminating the need for wiring which in turn reduces weight and simplifies the architecture. Wireless sensors are typically small, low-cost, low weight, and low-power devices that can be used to facilitate remote data acquisition in hard-to-reach and harsh locations in the aircraft. This paper discusses wireless sensor technologies and presents a prototype wireless sensor data acquisition module that was developed to investigate the feasibility of this technology for FTI data acquisition systems.
    • High Speed Target C-Band Feed Upgrade for Autotracking High Dynamic Targets

      Lewis, Ray; ViaSat Inc. (International Foundation for Telemetering, 2012-10)
      A new common aperture autotracking C-band feed, specifically designed to accurately track fast moving targets such as the Lance missile, is reviewed. Measured data demonstrates exceptional tracking modulation required for good tracking performance while simultaneously providing excellent data channel performance for high G/T over the entire 4.40-5.25 GHz band. The new patent applied for feed design allows users to maintain existing L/S-band capability with a cost effective field upgrade which adds high performance C-band capability to an existing telemetry tracking system.
    • High-Level Graphical User Interface to Streamline Mission Management of Dynamically Growing Data Transport Systems

      Hoffman, Richard W.; GDP Space Systems (International Foundation for Telemetering, 2012-10)
      As data transport systems become exponentially larger and more complex, the need to simplify the level of user involvement in establishing the intercommunication pathways becomes increasingly vital to streamlined, effective mission management. The proliferation of open-architecture, modular approaches to data transport and multiplexing systems shows the need for a unified, high-level control scheme that helps to flatten the users' learning curve for increasingly sophisticated, expanding systems. Implementing a control package with the functionality described in this paper will improve the user experience by eliminating the need for low level hardware management, minimizing system network footprint and unifying this functionality for a diverse hardware package.
    • Implementation of real-time DIS H.264 Encoder for Airborne Recorder

      Nam, Ju-Hun; Kim, Seong-Jong; Kim, Sung-Min; Lee, Nam-Sik; Kim, Jin-Hyung; Danam Systems Inc.; LG Electronics (International Foundation for Telemetering, 2012-10)
      When developing a video compression system in black box for aircraft, it is necessary to consider the characteristic of the images and the surrounding environment. The images captured in and out of aircraft have excessive movement-related issues, which make the results difficult to analyze and interpret. Failure to remove the tremors in the video component inevitably leads to poor compression efficiency and degrades the video imaging performance in the airborne black box. Therefore, it is necessary to develop a Compression System which can stabilize the video-image and efficiently utilize high compression recording for aircraft without special hardware. Based on the current situation, we suggest a real-time electronic video stabilization algorithm for airborne recorder which recovers shaky images simply and efficiently to work beside a developed stabilization system based on the H.264 Encoder using DSP.