• An Open Systems Architecture for Telemetry Receivers

      Parker, Peter; Nelson, John; Pippitt, Mark; MIT Lincoln Laboratory (International Foundation for Telemetering, 2012-10)
      An open systems architecture (OSA) is one in which all of the interfaces are fully defined, available to the public, and maintained according to a group consensus. One approach to achieve this is to use modular hardware and software and to buy commercial, off-the-shelf and commodity hardware. Benefits of an OSA include providing easy access to the latest technological advances in both hardware and software, enabling net-centric operations, and allowing a flexible design that can easily change as the needs of customers may change. This paper will provide details of an OSA system designed for a telemetry receiver and list the benefits of OSA for the telemetry community.
    • An Opportunistic Relaying Scheme for Optimal Communications and Source Localization

      Perez-Ramirez, Javier; New Mexico State University (International Foundation for Telemetering, 2012-10)
      The selection of relay nodes (RNs) for optimal communication and source location estimation is studied. The RNs are randomly placed at fixed and known locations over a geographical area. A mobile source senses and collects data at various locations over the area and transmits the data to a destination node with the help of the RNs. The destination node not only needs to collect the sensed data but also the location of the source where the data is collected. Hence, both high quality data collection and the correct location of the source are needed. Using the measured distances between the relays and the source, the destination estimates the location of the source. The selected RNs must be optimal for joint communication and source location estimation. We show in this paper how this joint optimization can be achieved. For practical decentralized selection, an opportunistic RN selection algorithm is used. Bit error rate performance as well as mean squared error in location estimation are presented and compared to the optimal relay selection results.
    • Optimized Constellation Mappings for Adaptive Decode-and-Forward Relay Networks using BICM-ID

      Borah, Deva K.; Kumar, Kuldeep; New Mexico State University (International Foundation for Telemetering, 2012-10)
      In this paper, we investigate an adaptive decode-and-forward (DF) cooperative diversity scheme based on bit interleaved coded modulation with iterative decoding (BICM-ID). Data bits are first encoded by using a convolutional code and the coded bits after an interleaver are modulated before transmission. Iterative decoding is used at the receiver. Optimized constellation mapping is designed jointly for the source and the relay using a genetic algorithm. A novel error performance analysis for the adaptive DF scheme using BICM-ID is proposed. The simulation results agree well with the analytical results at high signal-to-noise ratio (SNR). More than 5.8 dB gain in terms of SNR over the existing mappings is achieved with proposed mappings.
    • Overview of the Telemetry Network System (TMNS) RF Data Link Layer

      Kaba, James; Connolly, Barbara; SRI International (International Foundation for Telemetering, 2012-10)
      As the integrated Network Enhanced Telemetry (iNET) program prepares for developmental flights tests, refinements are being made to the Radio Access Network Standard that ensures interoperability of networked radio components. One key aspect of this interoperability is the definition of Telemetry Network System (TmNS) RF Data Link Layer functionality for conducting efficient communications between radios in a TDMA (Time Division Multiple Access) channel sharing scheme. This paper examines the overall structure of the TmNS RF Data Link Layer and provides an overview of its operation. Specific topics include Medium Access Control (MAC) scheduling and framing in the context of a burst-oriented TDMA structure, link layer encryption, the priority-enabled Automatic Repeat reQuest (ARQ) protocol, high-level network packet and link control message encapsulation, payload segmentation and reassembly, and radio Link Layer Control Messaging.
    • PCM to Ethernet: A Hybrid System Used to Certify the Next Generation of Data Transfer Technology

      de Souza, Luiz Fernando; Rios, Domingos Henrique Beolchi; Willis, Stephen; Embraer S. A.; Curtiss-Wright Controls Avionics & Electronics (International Foundation for Telemetering, 2012-10)
      The last few years has witnessed the adoption of Ethernet technology in an increasing number of FTI applications. This is a result of both the growing acceptance within the community of the application of the technology, the availability of suitable hardware and the desire for increased parameters/higher data rates that PCM is unable to accommodate. However, migrating from an existing PCM based networked system to Ethernet is not typically just a case of exchanging the necessary hardware. There can be a range of other issues that require addressing such as ensuring determinism and realizing previous investment in hardware - this paper highlights and discusses several of these. This paper presents a case study of an FTI application on the Embraer Legacy 500 where a hybrid PCM and Ethernet configuration was implemented. One reason for this configuration was that it was necessary to prove to the Brazilian Aeronautical Agency that the data acquired using an Ethernet system was as reliable as that acquired using PCM. An additional reason was that such a system was seen as a safe stepping stone to a full Ethernet system for programs in the near future which are planning to fully migrate to an Ethernet architecture.
    • PCM vs. Networking: Spectral Efficiency Wars - A Pragmatic View

      Araujo, Maria S.; Abbott, Ben A.; Southwest Research Institute (International Foundation for Telemetering, 2012-10)
      The expected efficiency of network-based telemetry systems vs. the tried and true PCM-based approaches is a debated topic. This paper chooses to use a lighthearted voice to pull the two sides of the "war" to a table of negotiation based on metrics. Ultimately, focusing on metrics that truly define efficiency is the key to understanding the varying points of view. A table of these metrics along with the "why and when" criteria for their use is presented based on historic mathematical information theory, true flight test data requirements, and lab analysis. With these metrics, the negotiation and reasonable compromises in the war may become clear. In other words, this paper attempts to provide a methodology that can be used by the community to aid in choosing the appropriate (or good enough) technologies for current and future telemetry testing demands.
    • Performance Evaluation of the AeroTP Protocol in Comparison to TCP NewReno, TCP Westwood, and SCPS-TP

      Nguyen, Truc Anh N.; Gangadhar, Siddharth; Umapathi, Greeshma; University of Kansas (International Foundation for Telemetering, 2012-10)
      Due to the unique characteristics of highly dynamic airborne telemetry environments, TCP when deployed in such networks suffers significant performance degradation. Given the limitations of TCP, the AeroTP opportunistic transport protocol with multiple reliability modes has been developed to specifically address the issues posed by telemetry networks. In our previous work, the different modes of AeroTP have been simulated and tested using the open source ns-3 network simulator. In this paper, we use ns-3 to evaluate the overall performance of AeroTP by comparing it with well-studied TCP variants: the widely-deployed TCP NewReno and TCP Westwood designed for wireless environments. Since space networks share many similar characteristics with telemetry environments, we also compare AeroTP with SCPS-TP.
    • Performance of Turbo Coded OFDM Modulation over an Aeronautical Channel

      Cole-Rhodes, Arlene; Dean, Richard; Moazzami, Farzad; Assegu, Wannaw; Fofanah, Ibrahim; Morgan State University (International Foundation for Telemetering, 2012-10)
      The main objectives of Integrated Network Enhanced Telemetry (iNET) are increased data rate and improved spectral efficiency. In this paper we propose the transmission scheme for the physical layer to be coded Quadrature Amplitude Modulation-Orthogonal Frequency Division Multiplexing (QAM OFDM) which enables high data rates and spectrum efficiency. However in high mobility scenarios, the channel is time-varying the receiver design is more challenging. In this paper pilot-assisted channel estimation is used at the receiver, with turbo coding to enhance the performance; while the effect of inter symbol interference (ISI) is mitigated by cyclic prefix. The focus of this paper is to evaluate the performance of OFDM with QAM over an aeronautical channel. The M-QAM with OFDM provides a higher data rate than QPSK hence it is chosen in this paper. The implementation is done using Inverse Fast Fourier Transform (IFFT) and the Fast Fourier Transform (FFT). This paper considers how the performance of Coded QAM OFDM can be enhanced using equalization to compensate for inter symbol interference, and using turbo coding for error correction.
    • Positional Awareness Map 3D (PAM3D)

      Hoffman, Monica; Allen, Earl; Yount, John; Norcross, April; NASA Dryden Flight Research Center; Arcata Associates, Incorporated (International Foundation for Telemetering, 2012-10)
      The Western Aeronautical Test Range of the National Aeronautics and Space Administration's Dryden Flight Research Center needed to address the aging software and hardware of its current situational awareness display application, the Global Real-Time Interactive Map (GRIM). GRIM was initially developed in the late 1980s and executes on older PC architectures using a Linux operating system that is no longer supported. Additionally, the software is difficult to maintain due to its complexity and loss of developer knowledge. It was decided that a replacement application must be developed or acquired in the near future. The replacement must provide the functionality of the original system, the ability to monitor test flight vehicles in real-time, and add improvements such as high resolution imagery and true 3-dimensional capability. This paper will discuss the process of determining the best approach to replace GRIM, and the functionality and capabilities of the first release of the Positional Awareness Map 3D.
    • The Process of Implementing a RF Front-End Transceiver for NASA's Space Network

      Thompson, Willie L., II; Wilder, Ali; Pannu, Randeep; Haj-Omar, Amr; Morgan State University (International Foundation for Telemetering, 2012-10)
      Software defined radio (SDR) introduces endless possibilities for future communication technologies. Instead of being limited to a static segment of the radio spectrum, SDR allows RF front-ends to be more flexible by using digital signal processing (DSP) and cognitive techniques to integrate adaptive hardware with dynamic software. We present the design and implementation of an innovative RF front-end transceiver architecture for application into a SDR test-bed platform. System-level requirements were extracted from the Space Network User Guide (SNUG). Initial system characterization demonstrated image leakage due to poor filtering and mixer isolation issues. Hence, the RF front-end design was re-implemented using the Weaver architecture for improved image rejection performance.
    • Quasi-Orthogonal Frequency Division Multiple-Access for Serial Streaming Telemetry

      Ponnaluri, Satya Prakash; Azimi-Sadjadi, Babak; Intelligent Automation Inc. (International Foundation for Telemetering, 2012-10)
      We propose a spectrally-efficient multiple-access technique that is particularly suitable for aeronautical telemetry applications involving serial streaming of data from multiple test articles to a ground station. Unlike conventional frequency-division multiple access, we assign overlapping frequency bands to different users with a minimum carrier separation corresponding to the symbol rate. We utilize multiuser detection strategies at the ground station to separate the transmissions from different test articles. As shown by the simulation results, the proposed scheme is robust to large frequency offsets due to oscillator offsets and Doppler shifts commonly encounters in aeronautical telemetry applications.
    • Relying on Telemetry for Mission Critical Decisions: Lessons Learned from NASA's Reusable Launch Vehicle for Use on the Air Force's Next Generation Reusable Launch Vehicle

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2012-10)
      The U.S. Air Force's next generation reusable booster (NGRSB) offers the opportunity for the Space Command to use intelligent equipment for decision making replacing personnel, increasing safety and mission assurance by removing decisions from program management personnel who may not have had any flight-test experience. Adding intelligence to launch vehicle and spacecraft equipment may include requiring the builder to use a prognostic and health management (PHM) program. The PHM was added to NASA's aircraft programs in 2009 and we have requested NASA HQ and NASA Marshal Space Flight Center adopt the NASA PHM in the procurement contracts used on the new Space Launch Systems, NASA's congressionally mandated replacement for the Space Shuttle. Space Vehicle Program managers often make decisions for on-orbit spacecraft without ever having on-orbit space flight experience. Intelligent equipment would have eliminated the catastrophic failures on the NASA Space Shuttle Challenger and Columbia. These accidents occurred due to the lack of space vehicle subsystem engineering personnel analyzing real-time equipment telemetry presented on strip chart and video data prior to lift off during pre-launch checkout for the Space Shuttle Challenger and the lack of space vehicle real-time equipment telemetry for Columbia. The PHM requires all equipment to include analog telemetry for measuring the equipment performance and usable life determination in real-time and a prognostic analysis completed manually will identify the equipment that will fail prematurely for replacement before launch preventing catastrophic equipment failures that may cause loss of life.
    • Remote-Sensed LIDAR Using Random Impulsive Scans

      Creusere, Charles D.; Castorena, Juan; New Mexico State University (International Foundation for Telemetering, 2012-10)
      Third generation full-waveform (FW) LIDAR systems image an entire scene by emitting laser pulses in particular directions and measuring the echoes. Each of these echoes provides range measurements about the objects intercepted by the laser pulse along a specified direction. By scanning through a specified region using a series of emitted pulses and observing their echoes, connected 1D profiles of 3D scenes can be readily obtained. This extra information has proven helpful in providing additional insight into the scene structure which can be used to construct effective characterizations and classifications. Unfortunately, massive amounts of data are typically collected which impose storage, processing and transmission limitations. To address these problems, a number of compression approaches have been developed in the literature. These, however, generally require the initial acquisition of large amounts of data only to later discard most of it by exploiting redundancies, thus sampling inefficiently. Based on this, our main goal is to apply efficient and effective LIDAR sampling schemes that achieve acceptable reconstruction quality of the 3D scenes. To achieve this goal, we propose on using compressive sampling by emitting pulses only into random locations within the scene and collecting only the corresponding returned FW signals. Under this framework, the number of emissions would typically be much smaller than what traditional LIDAR systems require. Application of this requires, however, that scenes contain many degrees of freedom. Fortunately, such a requirement is satisfied in most natural and man-made scenes. Here, we propose to use a measure of rank as the measure of degrees of freedom. To recover the connected 1D profiles of the 3D scene, matrix completion is applied to the tensor slices. In this paper, we test our approach by showing that recovery of compressively sampled 1D profiles of actual 3D scenes is possible using only a subset of measurements.
    • Resolution Analysis and System Integration of a Dynamically Reconfigurable FMCW Medical Ultrasound Imaging System

      Liebling, Michael; Lee, Hua; Lee, Michael; Doonan, Daniel; University of California, Santa Barbara (International Foundation for Telemetering, 2012-10)
      This paper describes the system performance analysis of the dynamically reconfigurable FMCW medical ultrasound imaging systems. Full-scale resolution analysis, for mono-static, bi-static, and multi-static data-acquisition formats, and laboratory experiment are included in the analysis.
    • A Runlength Coded LDPC Scheme for Insertion/Deletion Correction in Multimedia Watermarking

      Vasic, Bata; Vasic, Bane; University of Nis; University of Arizona (International Foundation for Telemetering, 2012-10)
      We describe a simple and effective coding scheme for insertion/deletion channels. It is based on runlength coding which converts a class of insertion/deletion channels that have infinite memory into memoryless channels, which are much easier to handle. Runlength coding is then combined with powerful error correction low-density parity-check (LDPC) codes designed for memoryless channels. We consider a novel applications of this technique in multimedia watermarking using quantization index modulation operating on the three dimensional mesh vertices. The runlength LDPC coding recovers the data hidden in the vertices removed by the process of mesh simplification.
    • Servo Controls for Low S/N Satellite Auto-Tracking

      Busch, Chuck E.; ViaSat Inc. (International Foundation for Telemetering, 2012-10)
      At very low Signal to Noise receive ratios, a typical Autotrack servo loop exhibits significant servo noise tracking jitter that can degrade the received signal characteristics. The angular jitter can be minimized by a lowering of the autotracking servo loop bandwidth, but at the sacrifice of the servos ability to reject external torque disturbances, such as wind deflections. As satellite downlinks continue to move to higher frequencies, the angular errors caused by either the tracking noise or the wind deflections of a receive antenna will have increasingly negative effect on the quality of the received data. This paper examines the performance of a servo algorithm that maintains the needed wide bandwidth characteristics of wind deflection rejection while achieving the noise smoothing characteristics of a very low bandwidth Autotrack servo response. The control algorithms have been tested on a 13 meter Remote Sensing Satellite tracking system to determine the overall tracking performance of the new implementation. Current results indicate that the new servo configuration achieves the desired results typical of a wide bandwidth system of high wind rejection and low target dynamics tracking errors. At the same time, it provides elimination of slowly changing errors from axis miss-alignments, thermal effects, and gravitational effects and the low RF noise jitter performance typical of a low bandwidth system.
    • Small Wearable Antenna for Animal Tracking

      Melde, Kathleen; Marcellin, Michael; Fowler, Jared R.; Austin, Jon M.; Estrada, Kathy T.; Velazquez, Martin; Mohr, Robyn; Sanchez, Ruben; University of Arizona (International Foundation for Telemetering, 2012-10)
      Many tracking devices exist in today's world. There are car tracking devices, hunting dog tracking devices, and even cell phone tracking devices. The use of Global Positioning Systems (GPS) has increased the ability to track various subjects throughout all parts of the world. However, there is no reliable tracking device for small mammals that allows researchers to maintain an unobtrusive distance from the animals. The goal of this project was to begin the process for designing a tracking system for small mammals. The overall system design utilizes a Garmin Astro 320 GPS tracking unit in order to focus on effectively reducing the size of the external antenna. Through the use of current technology and the knowledge of several engineering disciplines, an antenna was designed and embedded into a collar which connects with the Astro unit. This new antenna is compact and more suitable for tracking the Golden Lion Tamarin, a small monkey living in the Brazilian rain forest.
    • The Space Ground Link Subsystem (SGLS) Downlink Detection Improvement

      Washburn, Greg; Corman, David; ITT Exelis (International Foundation for Telemetering, 2012-10)
      The Space Ground Link Subsystem (SGLS) downlink signals are a PM/PSK modulation and have been detected at VAFB by detuning the receivers to the subcarrier frequency or by using cascaded demodulators. A recent demodulator enhancement by SEMCO allows a single box solution by internally routing the signals between FPGAs. This paper discusses the test methods and compares the results of the legacy methods of demodulation with the new demodulators.
    • Spectrum Efficient Technology Today, Tomorrow and Beyond

      Young, Tom; Santiago, Mark; Radke, Mark; Edwards Air Force Base (International Foundation for Telemetering, 2012-10)
      In preparation for the onslaught of the commercial wireless appetite, we, the test community, must continually invest in methods to better utilize the Department of Defense (DoD) Radio Frequency (RF) spectrum allocations and or leverage the shared commercial space. There is an ever increasing demand for the limited physical allocations within the RF spectrum for wireless communications. This has never been more prevalent within the test community as it is today with the continuing encroachment of the commercial wireless communication systems. These commercial entities are investing billions of dollars to insure that the bandwidth demands of the public are met which in turn will affect the DoD allocations and usage. Based on the need for increasing data rates, number of simultaneous tests, number of test participants and competition from the commercial sector, the test community must continually improve our efficiency of use within the wireless communications space. To accomplish this, the Test Resource Management Center (TRMC) has identified a Test Technology Area (TTA) Spectrum Efficient Technology (SET) that targets methodologies to more efficiently and effectively utilize this wireless test asset. The SET team has broken down the problem space into three distinct domains; wireless technologies, telemetry networking, and spectrum management. The idea therein is to maximize efficiency within the legacy use of the RF spectrum, while improving the utilization of this constrained resource with technology investment. Much of this work requires leveraging commercial technologies/trends and applying these technologies to the dynamic test environment problem space.
    • Spectrum Management in Telemetry Networks

      Fofanah, Jemilatu; Morgan State University (International Foundation for Telemetering, 2012-10)
      Spectrum efficiency is the key challenge in modern telemetry systems. Network telemetry requires moving from a dedicated link structure to a network structure which is a very complex problem and requires spectrum management tools. A mixed network structure has been previously proposed for networked telemetry which employs a combination of cellular and Adhoc networks. Significant improvements in QoS and clustering of the complex aeronautical networks have been observed and published in several venues. However in the earlier work routing within the Ad-hoc clusters has not been addressed and the clustering has been done using an enhanced K-means clustering. In this paper, a well known clustering algorithm is adopted in the mixed network concept and clustering of the Ad-hoc nodes are optimized based on shortest route to the gateway and minimum hop count criteria. The proposed clustering technique in this paper leads to a jointly optimized cluster-topology and gateway-selection solution a complex aeronautical network. Simulation results towards the end of this paper illustrate that with the proposed method, cluster configuration is locally optimized and the best gateway for each cluster is successfully selected. With addition of traffic measures to the consideration in the routing, the proposed solution will leads to efficient spectrum allocation and improved QoS.