• EFFECT OF ROTATING PROPELLERS ON TELEMETRY SIGNALS

      Geoghegan, Mark; Nusair, Marwan; Quasonix (International Foundation for Telemetering, 2019-10)
      The migration of aeronautical telemetry systems to C band has prompted a fresh look at many historically uninteresting facets of telemetry links. The effects of higher cable losses and smaller antenna beamwidths, for example, have been recognized and accounted for. Recent flight tests at Edwards AFB with a propeller-driven aircraft have revealed another such effect, which we have termed “prop chop”. Realtime data quality metric (DQM) values showed a periodic fluctuation in DQM, related to the aircraft engine speed. An investigation of this phenomenon using detailed electromagnetic simulation of a transmit antenna in the presence of a propeller shows a mechanism for this interference, both when the propeller is in front of the transmit antenna and when it is behind the transmit antenna. This paper compares the electromagnetic propagation simulation results to measured values from the field.
    • EFFECTS OF SWARM DENSITY ON MULTIHOP DRONE TELEMETRY DATA

      Rohrer, Justin P.; Naval Postgraduate School Monterey, Dept Computer Science (International Foundation for Telemetering, 2019-10)
      Bandwidth being a limited resource in airborne telemetry networks, drone swarms are particularly challenging to instrument due to the number of airborne nodes involved. Even a modest amount of data being transmitted by each node may overwhelm the network. Prior work has evaluated these effects in a number of drone swarm mobility scenarios,and shown the difficulty of achieving reliable data delivery. However, those results do not distinguish between data loss due to congestion of the available spectrum, and loss due to changing network topologies or disconnection due to mobility. In this work we attempt to isolate those effects by keeping a simulated drone swarm stationary,and focussing on the telemetry data delivery due to changing the size and density of the swarm. We compare the performance using no multi-hoprouting protocol, as well as using DSDV, AODV, DSR, and OLSR.
    • HIGH SPIN 105MM ARMAMENT OBR TECHNICAL PAPER

      Rotundo, Alfred; US Army - Army Futures Command; CCDC - Armament Center - Precision Munition Instrumentation Division (International Foundation for Telemetering, 2019-10)
      Developed an on-board-recorder (OBR) to capture both in-bore acceleration and in-flight canister expulsion forces for an artillery projectile. The instrumentation recorded on the OBR was fed into a model to simulate these forces. The OBR’s space claim was limited to the expulsion cavity of the artillery projectile. The OBR was equipped with an analog sensor suite that recorded battery, expulsion pressure, high-g in-bore axial accelerometer data, and radial spin data. Utilizing 8 channels of the ADC on the DSP, the sensors are recorded into both volatile SRAM and NOR Flash memory. The OBR matched both weight and center of gravity of the tactical artillery round. To accomplish this, multiple housing materials and potting materials were utilized. The OBR survived multiple shots. The OBR was instrumented successfully on 4 rounds, allowing an accurate model and simulation to be created to increase design reliability and minimize failures on future designs
    • HIGH-PERFORMANCE EXTENSIBLE SOQPSK (E-SOQPSK) MODULATION WAVEFORMS FOR AERONAUTICAL MOBILE TELEMETRY COMMUNICATIONS

      Lu, Cheng Y.; Argula, Rajeev; Sasvari, Gyorgy; Cook, Paul; Teletronics a Curtiss-Wright Company (International Foundation for Telemetering, 2019-10)
      To utilize the resilience to multipath and rapidly varying Doppler shifts offered by a multicarrier (MC) Orthogonal Frequency Division Multiplexed (OFDM) modulation waveform, and the high transmitter power efficiency offered by a single carrier (SC) Shaped Offset Quadrature Phase Shift Keying (SOQPSK) modulation waveform, we propose a novel Extensible Shaped Offset Quadrature Phase Shift Keying (E-SOQPSK) modulation waveform. E-SOQPSK is an OFDM structured single carrier modulation waveform, configurable to include OQPSK, SOQPSK, or mQAM. Preliminary laboratory results confirmed its low Peak-to-Average Power ratio (PAPR) and high spectrum efficiency. Preliminary simulations demonstrated multipath resilience of ESOQPSK waveform by utilizing OFDM structure based Frequency-Domain equalization at receiver.
    • Hybridization of wireless technologies for the aerospace instrumentation

      Percie du Sert, François-Gabriel; Zodiac Data Systems (International Foundation for Telemetering, 2019-10)
      Whatever the flight test or space launch vehicle, instrumentation presents strong intrusiveness due to cabling. The industry is resolutely looking for a transition toward wireless architectures for elimination of cabling while not compromising data integrity and network performances. The ideal wireless solution is a single technology that could encompass all the needs. But there is a wide variety of use cases and associated requirements: data throughput, synchronization accuracy, power consumption, robustness of the link, frequency regulation constraints. Today, no technology is able to cover all these needs. However, multiple technologies show specific characteristics that are optimized for some particular use cases. Hybridization of multiple wireless technologies in a complex system is the right solution to address specific applications with the optimal wireless instrumentation solution and no concession on performance.
    • Implementation and Benefits of Best Source Selection

      Gerstner, Grant; Normyle, Dennis; NAVAIR Atlantic Division (International Foundation for Telemetering, 2019-10)
      A comprehensive guide to implementing best source selection at a test range. This paper uses the history of the Atlantic Test Range's implementation as a guide to show the steps needed to implement Best Source Selection. It also discusses the advantages to best source selection at all levels of implementation.
    • Intelligent Monitoring Technology of Flight Test Based on Automatic Identification of Test Points

      Shenghu, Liu; Zhe, Yang; Bing, Ye; Chinese Flight Test Establishment (International Foundation for Telemetering, 2019-10)
      As the smallest component unit of the flight test task, test point defines the tasks and requirements to be completed by the test aircraft, which is the main basis for the flight effect evaluation. This article through in-depth analysis parameters variation characteristics of the testing aircraft in different test points, combined with the prior knowledge that the domain experts artificial recognize test points, extraction the key parameters of influencing test point identification, and their change rule. We constructed the knowledge base for test point identification, designed test point automatic identification algorithm. Combined with the flight test real-time task evaluation technology, we developed the real-time monitoring system for flight test based on the test point automatic identification and intelligent evaluation. It realized the change from the "intelligent security monitoring" to "intelligent task monitoring", and effectively improve the flight efficiency of the test aircraft.
    • INTERFERENCE MITIGATION OF ADJACENT RADIO FREQUENCY SIGNALS ON A FLEXIBLE SOFTWARE-DEFINED RADIO TESTBED PLATFORM

      Gonzalez, Virgilio; Elahi, Mirza M.; Sandoval, Jose C.; Corral, Pabel; Yasuda, Susumu; Univ Texas, Computational Science Program; Univ Texas, Dept Electrical and Computer Engineering; White Sands Missile Range, U.S. Army Test and Evaluation Command (International Foundation for Telemetering, 2019-10)
      The radio frequency (RF) spectrum is crowded with users and adjacent frequency users are facing an increase in interference from each other. The spectrum governing body Federal Communications Commission (FCC) has the difficult task of allocating spectral bands for new users for mobile devices using 4G LTE technology. Telemetry (TM) is affected by the adjacent band 4G LTE users in terms of signal degradation. To minimize the interference between adjacent frequency users, several methods can be used. A common but inefficient method separates adjacent band frequencies using guard bands which leaves a big portion of the spectrum unused. Alternatively, adjacent RF signals can be separated using digital filtering techniques with the signal of interest being unharmed and reducing the signal power of the interfering signal. A digital filtering technique includes bandpass filter (BPF) rejection, which has the ability to filter out adjacent interfering signals. This is accomplished by designing bandpass digital filters where the passband and stopband frequencies are adjusted to achieve maximum signal power and reject the interfering signal by reducing its power. A flexible software-defined radio testbed is set up to experiment and analyze this scenario with ease and effective measures.
    • Investigation into the Development of a Wireless IoT Penetration Testbed

      Thompson II, Willie L.; White, Tellrell; Morgan State University (International Foundation for Telemetering, 2019-10)
      IoT protocols have been proposed to replace wired systems in aircraft to support telemetry applications. They offer several advantages to wired systems due to them being wireless, low cost, and consuming less power. However, the one consideration that is often overlooked is the security of these wireless protocols. This project focused on investigating the use of open source hardware and software frameworks to create a wireless testbed to conduct penetration testing of the ZigBee protocol. To accomplish this task, the open source XBee software library was used to implement the ZigBee Network and Application Layers within the GNU Radio IDE. The XBee hardware module was leveraged for the IEEE 802.15.4 PHY and MAC Layers.
    • JAMI AND TENA - A FUSION OF GPS AND IP

      Sandberg, Alvia; Morse, Caleb; Chandler, Ryan; Redstone Test Center (International Foundation for Telemetering, 2019-10)
      The Joint Advanced Missile Instrumentation (JAMI) project has created a very effective high dynamic Time Space Position Information (TSPI) solution and the Test and Training Enabling Architecture (TENA) is a very effective way to share data over a network. Can JAMI and TENA work together? This paper answers that question.
    • JFLUTTER REAL TIME FLUTTER ANALYSIS IN FLIGHT TEST

      Rubio, Pedro; Coll, Francisca; AIRBUS DEFENCE & SPACE Flight Test (International Foundation for Telemetering, 2019-10)
      During the development of an aircraft it is mandatory to demonstrate that the aircraft is free from flutter within its operational flight envelope. This piece showcases JFlutter, a flutter analysis tool developed within Airbus Defence & Space Flight Test Analysis Tools. JFlutter allows the analysis of this phenomenon in real time monitoring and post flight mode. Using the FxS dataserver as data provider, a reliable data gathering mechanism has been used for this critical tool. As flutter means aero elastic instability, potentially dangerous, flight safety becomes a main requirement. For safety reasons and in order to reduce overall test program duration it is necessary to check predicted frequencies and damping in real time / monitoring.
    • JOINT LTE UPLINK INTERFERENCE AND MULTIPATH SUPPRESSION FOR AERONAUTICAL TELEMETRY USING MMSE INTERFERENCE CANCELER

      Shoudha, Shamman Noor; Saquib, Mohammad; Univ Texas, Dept Electrical Engineering (International Foundation for Telemetering, 2019-10)
      This paper addresses the use of a minimum-mean-square-error (MMSE) interference canceler for mitigating the Long-Term Evolution (LTE) uplink interference and multipath in Aeronautical Telemetry system. SOQPSK-TG modulation scheme for the telemetry victim signal and 64-QAM for the LTE interference signal are considered. For a multipath channel derived from the channel sounding data, the interference canceler achieves the target bit error rate (BER) of 10-5 at Carrier-to-Interference (C/I) ratio - 12.7, - 40.7 and – 36 dB for data rates 1, 5 and 10 Mbits/s, respectively. To offer the same performance, an MMSE channel equalizer requires C/I ratio - 10.9, - 25.0 and - 5.0 dB.
    • Latest Development Status on the Commercial derivative aircraft Based Instrumentation Telemetry System (CBITS) Program

      Roudebush, J. Kyle; Hernandez, Jose; Kujiraoka, Scott; NAVAIR-Point Mugu; GBL Systems (International Foundation for Telemetering, 2019-10)
      The Commercial derivative aircraft Based Instrumentation Telemetry System (CBITS) project will provide an advanced airborne telemetry system and capability to support the test and evaluation (T&E) of current and future military weapons and defensive systems. In conjunction with the Range Support Aircraft (RSA) contracts, the CBITS project will provide an autonomous airborne T&E asset capable of supporting Major Range and Test Facility Base (MRTFB) government ranges and open-ocean testing worldwide. The project will develop an improved S-Band airborne telemetry (TM) capability and a new L- and C-Band telemetry capability as a result of frequency spectrum selloff issues. These improved telemetry capabilities, along with the existing airborne Flight Termination System/Command Destruct (FTS/CD) capability, existing radar for Range Surveillance (RS) and Range Clearance (RC), and range unique augmenting communication systems will be integrated into a Gulfstream G550 Airborne Early Warning (AEW) RSA which will be replacing the current NP-3D Remote Area Safety Aircraft (RASA). This paper will discuss the latest developmental status of the CBITS project.
    • LDPC CODING FOR FREQUENCY DIVERSITY IN MULTI-CHANNEL AIR-TO-GROUND TELEMETRY

      Deshmukh, Mrugen A.; Wilson, Stephen G.; Univ Virginia, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      We consider the application of LDPC codes for improving performance in multi-channel (spectrum aggregation) for air-to-ground telemetry, by virtue of frequency diversity available on a wideband frequency-selective multipath channel. Our particular interest is in use of multi-channel OFDM transmission on “white spots” in the microwave spectrum. Each such channel is subject to frequency-selective fading over its bandwidth (typically a few MHz) due to multipath, for which typical OFDM equalization is standard. However, some subcarriers within this OFDM channel may experience deep fading at the output of the equalizer, rendering the symbol error probability poor relative to that on an AWGN channel at the same average SNR. We study simulated performance on a multipath channel described by the ETU fading model. Specific performance reported includes error rate of LDPC coding constrained to a single channel (effective diversity order roughly 2) and error rate of coding across eight channels (diversity order roughly 5). Further, performance on this dispersive fading channel is only about 3 dB worse than that on a no-multipath channel, at block error probability 0:01.
    • LESSONS LEARNED DURING THE INTRODUCTION OF NETWORK / IP TELEMETRY IN FLIGHT TEST INSTRUMENTATION FOR HELICOPTERS

      Urli, Renaud; Mertl, Florian; Flight Test Instrumentation, Dept. ETXMI; Airbus Helicopters Deutschland GmbH; Industriestrasse 4 (International Foundation for Telemetering, 2019-10)
      Flight Test Instrumentation (FTI) architectures are moving more and more towards network topologies. For almost every task, current equipment support connection to the FTI system via Ethernet. However, up to now, the telemetry link has kept the legacy PCM technology for most applications. By implementing network / IP radios, the drawbacks of old fashioned PCM-based telemetry links could be eliminated. Furthermore, new use cases have become possible, and the architecture of FTI installations, both on board and on ground, could be simplified. This paper gives some technical background on networked / IP radios and describes the steps taken during the first introduction of this promising technology. The benefits of this system are explained in order to show the potential of that approach. Beside this, important lessons were learned during the introduction of the network / IP telemetry: from software to hardware topics, from topology to human factors aspects. Eventually, the present installation at the FTI facility is described as well as the status of the migration from S-band PCM/FM to IP C-Band.
    • LIDAR COLLISION AVOIDANCE SYSTEM WITH AUDIO FEEDBACK FOR VISUALLY IMPARIED INDIVIDUALS

      Lee, Hua; Maravilla, Julian; Shimada, Haruka; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      In this paper, we present the 4th-generation, light-weight low-power collision avoidance system. For this new version, the ultrasound transmitter of the data-acquisition component is replaced by a Lidar to avoid multi-paths in complex environments. The estimate of the target range is quantized into a frequency bin and represented by acoustic waveforms within the human hearing range. The bearing angle of the target is utilized to produce the temporal offset between the twin channels of the corresponding acoustic waveforms. This wearable and hearable device is designed for real-time navigation for the blind.
    • LTE-BASED AERONAUTICAL MOBILE TELEMETRY - LAB AND FIELD TEST EXPERIMENTS

      Beck, Eric; Erramilli, Shobha; Habiby, Sarry; Johnson, William; Kogiantis, Achilles; Maung, Nan; Rege, Kiran; Sayeed, Zulfiquar; Triolo, Anthony; Young, Jeffrey; et al. (International Foundation for Telemetering, 2019-10)
      Aeronautical mobile telemetry (AMT) based on 3GPP’s LTE standard is implemented in a proof-of-concept system. The solution tackles the very high Doppler shifts expected in flight tests using an appliqué that can be inserted between the transmit/receive ports of the Test Article (TA) and the antennas. This appliqué estimates the Doppler shift and proactively compensates for it on the uplink signal being transmitted by the TA. The overall system has been tested under different operational conditions in a laboratory setup as well as in the field. In the laboratory setup, the desired operating conditions are created with a set of Software-Defined-Radio-based channel emulators coupled with a computer to control their behavior. In order to carry out field tests, an operational LTE network has been created at Edwards Air Force Base (EAFB) with two base stations, backhaul links, and a core network. In this paper, we provide descriptions of both laboratory and field test setups as well as the results of several tests that have been carried out to date. The results of lab and field tests lend strong support to the viability of this AMT solution.
    • MITIGATION OF ANTENNA POLARIZATION TRANSFORMATIONS CAUSED BY AIRFRAME REFLECTIONS

      Geoghegan, Mark; Nusair, Marwan; Quasonix (International Foundation for Telemetering, 2019-10)
      The majority of aircraft telemetry antennas transmit a linearly polarized wave. These linearly polarized signals are often received by two orthogonal (left and right hand) circularly polarized receive antennas, each of which has 3 dB polarization loss. Under nominal conditions, a diversity combiner can be used to coherently add the two received signals, thereby restoring the 3 dB loss. Recent flight tests have revealed that the signals radiating from the aircraft are actually elliptically polarized or even circularly polarized, leading to degraded combiner performance. This paper describes how the transmit polarization can be transformed from linear to circular, why this degrades combiner performance, and how to mitigate this effect.
    • MOVING TOWARDS 10 GbE NETWORK SWITCHES AND RECORDERS

      Moore, Russell; Moroni, Jacob; Curtiss-Wright Defense Solutions (International Foundation for Telemetering, 2019-10)
      With flight test data acquisition and avionic bus data demands increasing every year, a new breed of network switches and recorders are needed to handle the new extreme data load to aggregate and record on solid-state media. Flight test instrumentation switches and recorders must perform in harsh environments with ultra-high levels of reliability. They must also facilitate fast and efficient movement and storage of data. Switches also require many features such as data aggregation, port-mirroring, and QoS (Quality-of-Service) support while recorder features such as port truncation, and support for PCAP, DARv3 & CH10 recording formats are important. This paper will discuss these needs and outline some use cases for new 10 GbE network switches and recorders.