• Adaptive Modulation Schemes for OFDM and SOQPSK Using Error Vector Magnitude (EVM) and Godard Dispersion

      Han, Jieying; Walkenhorst, Brett T.; Wang, Enkuang D.; Georgia Tech Research Institute (International Foundation for Telemetering, 2014-10)
      In this paper, we develop a new approach which enables adaptation across two modulation schemes in the iNET standard: orthogonal frequency-division multiplexing (OFDM) and shaped-offset quadrature phased-shift keying (SOQPSK). We present the error vector magnitude (EVM) for OFDM and second-order Godard dispersion (D(²)) for SOQPSK as our link metrics that measure the degradation due to thermal noise and channel effects and then derive the mathematical relationship between these two metrics. This relationship enables us to utilize a set of empirically-derived rules that incorporate both modulation schemes.
    • Addressing the Challenges Created by Large Networked Ethernet FTI Systems

      Quinn, Pat; Curtiss-Wright Defense Solutions (International Foundation for Telemetering, 2014-10)
      As Flight Test Instrumentation (FTI) systems move away from traditional PCM towards Ethernet, a whole new set of system level considerations must be taken into account. This is particularly true when these systems consist of dozens of data acquisition systems (DAUs) and multiple layers of switches. This paper discusses the challenges presented by very large Ethernet based systems and the methodologies developed to address these during a recent application.
    • Advanced Monitoring Techniques

      Rubio, Pedro; Gonzalez, Moises; Roses, Diego; Lopez, Rodrigo; Airbus Defence and Space (International Foundation for Telemetering, 2014-10)
      The State of The Art in Operating Systems and new human machine interfaces are moving forward quickly. Flight Test Data Processing Department has developed new tools for monitoring Flight Tests using new computer technologies like .NET virtual machines, "on-the-fly" compilation, intelligent behavior, multi-touch capabilities and high performance vector graphics libraries. All these new techniques allows the user to optimize Flight Tests reducing the time for taking decisions, helping to make complex calculations in real time and adapting the visualization displays to Flight Test Engineers requirements in real time.
    • Application of TENA in Real-Time Wireless Flight Test Engineering with Tablet Support

      Cornelius, Harold; Treakle, Thomas; TENA in Resource Constrained Environments (TRCE) (International Foundation for Telemetering, 2014-10)
      Flight line checkout of aircraft and Unmanned Aerial Systems (UAS) is a necessary part of Test Range operations. Checkout systems have been designed to support the Flight Test Engineer (FTE) and aircraft technicians to validate the operations of the aircraft instrumentation systems and to help in troubleshooting problems. Current systems in use by the FTE include using range assets, such as range Telemetry Receiving system, and even home built systems. One system used at Edwards Flight Test Center is called the Instrumentation Ground Support Units (IGSU) or "Taco Carts", a system that contains the basic elements of a telemetry ground system that also has the additional capability to connect directly to the aircraft. This presentation shows advancement prototypes that enable the FTE access to modern technologies that will provide efficiencies using wireless networks, tablets and the Test and Training Enabling Architecture (TENA) TENA through activities developed as part of the TENA in Resource Constrained Environments (TRCE) project.
    • Buy versus Develop: A NAND Flash Controller Case Study

      Budd, Chris; SMART High Reliability Solutions, Inc. (International Foundation for Telemetering, 2014-10)
      The decision to buy or develop any system component is a difficult one. Clearly, the development time and cost is less when using an off-the-shelf component; however, these components attempt to meet the requirements of a main-stream market segment. Outside of those markets, a designer may need to add unique features to solve problems for specialty markets; one example is SSDs for telemetry markets where one critical component is the NAND flash controller. This paper will focus on some of the requirement differences and why it is so important for SSD designers to develop their own controller for these markets.
    • C Band Telemetry at Airbus Flight Test Centre

      Fréaud, Gilles; Airbus (International Foundation for Telemetering, 2014-10)
      Airbus is authorized to use S-band for Telemetry transmission until 2015. In October 2011, the decision was taken to move to C-band in 2013, to cope with Airbus development aircraft planning. The objective was a real challenge for 2 main reasons: C-band channel was not characterized in Airbus transmission environment and it was necessary to validate the propagation performance for Flight Tests uses. The selected solution is based on Coded Orthogonal Frequency Division Multiplexing (COFDM) modulation. There was no existing solution so it has led the Airbus Test Centre to drive the development of its own C Band solution. C-band telemetry at Airbus has been tested and evaluated in flight from April 2012. The first goal was to check the coverage and the impact of the bad weather condition. Besides, it was necessary to characterize the channel to choose the optimised parameters for the waveform in the Toulouse Blagnac environment. This selection of parameters allows the high quality and increased data rate required for Airbus Telemetry to be reached. The test results consolidated the choice of a COFDM modulation, when given the high sensitivity to multipath of usual Frequency Modulation in the airport environment full of buildings and aircrafts. Moreover, it has been possible to reach a similar quality to the S-band telemetry systems, thanks to a fine tuning of the waveform parameters, and tracking system. Deployment of the system by modifying 8 reception antennas and 12 development aircrafts was done over a span of 4 weeks in January 2014. No impact on Airbus A350 certification campaign occurred due to close collaboration with Flight Test Operations. The new Telemetry system enables an increase of telemetry capabilities in the future, especially the data throughput, simplified remote control and monitoring. This experience is an opportunity to set up a new standard.
    • Comparing Packet Fill Strategies in Ethernet-Based Data Acquisition Systems

      Penna, Sérgio D.; EMBRAER Flight Test Instrumentation (International Foundation for Telemetering, 2014-10)
      Ethernet-based data acquisition systems are becoming more and more common in the Flight Test Instrumentation environment. Digitized analog sensor output and various other types of digital data is captured and inserted into Ethernet packets using a "packet fill" strategy that in general is under control of the user. This paper discuss and compares two strategies "FILL-TO-TIME" and "FILL-TO- SIZE" for the acquisition of ARINC-429 digital data bus.
    • A Comparison of Compressive Sensing Approaches for LIDAR Return Pulse Capture, Transmission, and Storage

      Creusere, Charles D.; Castorena, Juan; New Mexico State University (International Foundation for Telemetering, 2014-10)
      Massive amounts of data are typically acquired in third generation full-waveform (FW) LIDAR systems to generate image-like depthmaps of a scene of acceptable quality. The sampling systems acquiring this data, however, seldom take into account the low information rate generally present in the FW signals and, consequently, they sample very inefficiently. Our main goal here is to compare two efficient sampling models and processes for the individual time-resolved FW signals collected by a LIDAR system. Specifically, we compare two approaches of sub-Nyquist sampling of the continuous-time LIDAR FW return pulses: (i) modeling FW signals as short-duration pulses with multiple bandlimited echoes, and (ii) modeling them as signals with finite rates of innovation (FRI).
    • A Comparison of Three Equalization Techniques for iNET-formatted SOQPSK-TG

      Rice, Michael; Afran, Md. Shah; Saquib, Mohammad; Cole-Rhodes, Arlene; Moazzami, Farzad; Brigham Young University; University of Texas at Dallas; Morgan State University (International Foundation for Telemetering, 2014-10)
      This paper demonstrates the effectiveness of the zero-forcing, minimum mean-squared error, and constant-modulus equalizers in improving the BER performance of iNET-formatted SOQPSK-TG. The equalization algorithms leverage the existence of known bit sequences in the preamble and ASM fields of the iNET packet to realize data-aided equalizers. The effectiveness of these equalization techniques over ten test channels, derived from channel sounding experiments at Edwards AFB, was evaluated. The BER curves for nine out of the ten test channels display the desirable "waterfall" shape. The BER curve for the remaining test channel displays a "BER floor." Fortunately, the "BER floor" is low enough to allow error correcting codes, such as the iNET LDPC code, to correct the errors and provide virtually error-free performance.
    • Data Consistency Checks on Flight Test Data

      Mueller, G.; Airbus Defence and Space (International Foundation for Telemetering, 2014-10)
      This paper reflects the principal results of a study performed internally by Airbus's flight test centers. The purpose of this study was to share the body of knowledge concerning data consistency checks between all Airbus business units. An analysis of the test process is followed by the identification of the process stakeholders involved in ensuring data consistency. In the main part of the paper several different possibilities for improving data consistency are listed; it is left to the discretion of the reader to determine the appropriateness these methods.
    • DAU and Ground Station Set Up - Concept of Operations

      Eccles, Lee H.; Moore, Jessica D.; Stiers, Richard D.; Boeing Test & Evaluation (International Foundation for Telemetering, 2014-10)
      Many systems in use today to generate the set up information for Data Acquisition Units (DAUs) and for Telemetry Ground Stations are tailored around the requirements for a particular set of supplier's hardware. This makes adding support for a new supplier a costly operation. An attempt is under way to enable development of a system that could be used to set up a DAU and a Telemetry Ground Station with equipment from the currently existing suppliers as well as future suppliers. The goal is to reduce the impact of adding a different supplier's hardware into a system. As the first step in this process it was necessary to agree upon a Concept of Operations that could meet the needs of multiple companies. Once the Concept of Operations was developed then the standards necessary to enable the development of this type of a system could be considered. This paper discusses the Concept of Operations that was developed and the rationale behind the decisions that were made.
    • Determination of Position Around Near-Earth Asteroids Using Communication Relays

      Nelson, Evan; Creusere, Charles D.; Butcher, Eric; New Mexico State University; University of Arizona (International Foundation for Telemetering, 2014-10)
      In this paper we consider the possibility of using a communications system that is operating between probes on the surface of an asteroid and an orbiting satellite to more accurately determine spatial positions. This is done by measuring the round trip communication delay between the orbiter and various surface probes to estimate distance. From these distance measurements, the position can be determined using trilateration - the same basic technique behind the earth-based GPS system. Within the framework of this scenario, the location of the probes or the orbiter can be determined depending on the scenario.
    • Development and Usage of IF Recorders in Range Systems

      Salisbury, Jack; Cornelius, Harold E.; Pennington, Gregory A.; Atlantic Test Range (International Foundation for Telemetering, 2014-10)
      Accurate reproduction of RF transmissions for test and development has been out of reach for some time. The testing of RF equipment, multipath generation and downstream TM processing systems has been done in the past with varying levels of accuracy. In the past the techniques of checking TM equipment worked, but lacked realism that real TM transmissions provide. This paper describes the development of an IF recorder for range TM. We discuss the usage of a recorder with multiple channels, time correlation, channel skew capability, IF over IP capabilities and file management will allow repeatable, realistic testing of TM systems.
    • Direction of Arrival Estimation of Broadband Signal Using Single Antenna

      Xin, Hao; Yu, Xiaoju; University of Arizona (International Foundation for Telemetering, 2014-10)
      In this paper, we propose a novel technique using a single antenna for direction of arrival (DOA) estimation of broadband microwave signals. We designed and fabricated a microstrip-leaky-wave receiving antenna, which has good matching and reasonable radiation efficiency in the frequency range of interest: 2 - 3.5 GHz. Because the frequency response of the antenna is strongly incident-angle dependent, by using the spectral information at the antenna, we are able to estimate the DOA of a broadband microwave signal with a high degree of accuracy. Simulations and experiments show that the proposed technique enables good DOA estimation performance within a 90˚ range.
    • A Duel Compression Ethernet Camera Solution for Airborne Applications

      Willis, Stephen; Langer, Bernd; Curtiss-Wright Defense Solutions; Kappa Aptronics (International Foundation for Telemetering, 2014-10)
      Camera technology is now ubiquitous with smartphones, laptops, automotive and industrial applications frequently utilizing high resolution imagine sensors. Increasingly there is a demand for high-definition cameras in the aerospace market - however, such cameras must have several considerations that do not apply to average consumer use including high reliability and being ruggedized for harsh environments. A significant issue is managing the large volumes of data that one or more HD cameras produce. One method of addressing this issue is to use compression algorithms that reduce video bandwidth. This can be achieved with dedicated compression units or modules within data acquisition systems. For flight test applications it is important that data from cameras is available for telemetry and coherently synchronized while also being available for storage. Ideally the data in the telemetry steam should be highly compressed to preserve downlink bandwidth while the recorded data is lightly compressed to provide maximum quality for onboard/ post flight analysis. This paper discusses the requirements for airborne applications and presents an innovative solution using Ethernet cameras with integrated compression that outputs two steams of data. This removes the need for dedicated video and compression units while offering all the features of such including switching camera sources and optimized video streams.
    • Dynamic Capacity Allocation Algorithms for iNET Link Manager

      Fecko, Mariusz; Change, Kirk; Cichocki, Andrzej; Kim, Heechang; Gadgil, Shree; Sarraf, Mohsen; Barton, Melbourne; Wong, Larry; Samtani, Sunil; O'Connell, Ray; et al. (International Foundation for Telemetering, 2014-10)
      In an iNET telemetry network, Link Manager (LM) dynamically allocates capacity to radio links to achieve desired QoS guarantees. Under the T&E S&T iMANPOL program, we developed an enhanced capacity allocation algorithm that can better cope with severe congestion and misbehaving users and traffic flows. We compare the E-LM with the LM baseline algorithm (B-LM), which employs priority-weighted allocation. The B-LM is expected to perform well for the majority of traffic patterns, but does not prevent an ill-behaved traffic class from causing excessive latency on other radio links. The E-LM ensures that each class has a "guaranteed" portion of the total available bandwidth that is proportional to the weight of the class. If the traffic loading of a class is lower than its quota, the difference can be flexibly shared by other classes across multiple links. If the traffic loading of a class is higher than its quota, its demand may still be satisfied, provided that the capacity is not taken away from well-behaved traffic classes that stay below their quotas. The qualitative analysis shows the E-LM provides lower latencies for the well-behaved links in overloading conditions and increases the overall system throughput when the traffic is unbalanced. We conducted extensive experiments to confirm that analysis, with the E-LM reducing latency of well-behaved flows up to 90%, and increasing overall throughput up to 65% over the B-LM.
    • Earth Orbital Debris - History and Implications

      Hill, Jerry; Avum, Inc. (International Foundation for Telemetering, 2014-10)
      Objects of varying sizes shapes, and origins, referred to as space debris, or "space junk," have been accumulating in Earth orbit for over a half century. This personal glimpse into this fascinating subject discusses sources of space debris and the implications of this debris to working near Earth space vehicles and orbiting laboratories.
    • Energy Efficient Water-Filling Algorithm for MIMO-OFDMA Cellular System

      Kassa, Hailu Belay; Mariam, Dereje H.; Moazzami, Farzad; Astatke, Yacob; Addis Ababa University; Morgan State University (International Foundation for Telemetering, 2014-10)
      In this work we evaluated the performance of different water filling algorithms. We have selected four power allocation algorithms: Conventional water-filling (CWF), Constant power water-filling, Inverse Water-filling (IWF), and Adaptive Iterative Water-Filling (AIWF) algorithms. Capacity is the performance metric we used to compare the above algorithms by taking the optimality of transmission power allocation to each sub-channel into account. The power allocation can be calculated with a reference of the water level value that has different approaches for different algorithms. The water level can either be fixed once it is found, or it may be adaptive or different for different sub-channels. Hence, the results show that the adaptive iterative water filling (AIWF) algorithm has a better effect on the performance of MIMO-OFDM system by allocating power adaptively.
    • An Engineer's Guide to TMoIP

      Hoffman, Richard W.; GDP Space Systems (International Foundation for Telemetering, 2014-10)
      As telemetry transport systems move inexorably closer to a unified telemetry-over-IP approach, the operators and engineers who have traditionally deferred to a separate communications group can benefit from a more comprehensive understanding of the intricacies of the transport medium and protocol. Ethernet, and more specifically IP network hardware, has gained increased robustness, as well as much of the reliability enhancing functionality of more venerable transport solutions, but with these increasingly integrated feature sets comes an emphasized demand on the telemetry systems operator to be able to configure the telemetry transport network devices in more dynamic environments. This paper will seek to serve as a handbook for the telemetry community, guiding discussions of the strengths, weaknesses, legacy, and future outlook of this transport methodology both within and without the groups involved in most range telemetry transport environments.
    • Enhanced Query Data Recorder (EQDR) - A Next Generation Network Recorder Built Around iNET Standards

      Wigent, Mark A.; Mazzario, Andrea M.; Leidos; Kauai Software Solutions (International Foundation for Telemetering, 2014-10)
      The Enhanced Query Data Recorder (EQDR) has been developed under the Test Resource Management Center's (TRMC) Spectrum Efficient Technologies (SET) T&E S&T program. The EQDR is a network flight recorder built around the iNET standards and which is intended to meet the future needs of the networked telemetry environment. The EQDR is designed to support the "fetch" of recorded test data during a test without interruption to the ongoing recording of data from the test article vehicle network. The key benefits of the network data recorder as implemented in the EQDR are increased flexibility and efficiency of test in an environment with increasing demands on spectrum available for telemetered data. EQDR enables retrieval of individual recorded parameters on an as-needed basis. Having the flexibility to send data only when it is required rather than throughout the duration of the test significantly increases the efficiency with which limited spectrum resources are used. EQDR enables parametric-level data retrieval, based not only on time interval and data source, but also on the content of the recorded data messages. EQDR enables selective, efficient retrieval of individual parameters using indexes derived from the actual values of recorded data.