• DEVELOPING WIRELESS IMUS TO SIMPLIFY INTEGRATION INTO DYNAMIC SYSTEMS

      Kosbar, Kurt; Lipina, Jacob; Christmas, Austin; Marcolina, Rebecca; Missouri University of Science and Technology (International Foundation for Telemetering, 2019-10)
      This paper discusses the development of wireless inertial measurement units (IMUs) designed to transmit data from a prototype Mars rover to a remote base station. These nine degree of freedom, multi-chip modules provide measurements for linear acceleration, angular rotation velocity, and magnetic field vectors for the rover’s chassis and robotic arm end-effector. To facilitate integration into these dynamic systems, each unit is independently powered and has a form factor of 108 cc. IMU data is sent from 32-bit microcontrollers with embedded IEEE 802.11 b/g/n Wi-Fi to the rover via UDP transport through a custom publish/subscribe distributed IP protocol. Data is relayed over two circular polarized omnidirectional antennas to the base station’s dual linear MIMO Yagi-Uda antenna. The information gathered provides operators a heading and orientation to improve situational awareness, as camera visuals are often inadequate.
    • 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.
    • Adaptive OFDM for Aeronautical Channels

      Moazzami, Farzad; Dean, Richard; Zegeye, Wondimu K.; Alam, Tasmeer; Morgan State University, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Previous work modeled the cruise phase of an aeronautical channel and showed how the channel varied as a function of height, distance, and speed. What was apparent from that analysis was that the ``cruise" channel was remarkable stable and varied slowly and predictably over time. The steady state channel reflected a 2-ray multipath model which exhibits deep nulls in the spectrum which affects serial tone modems significantly. Further the application of parallel tone modulation improves performance except for that portion of the band which was degraded by the null. This points to the use of Adaptive OFDM (AOFDM) structure wherein tones are only sent in portions of the band which are strong and not areas where the signal is weak. This work develops a method for capturing a profile of the Signal to Distortion Ratio (SDR) for each tone for each frame and over time. It also develops a method for converting the SDR per tone to estimate the optimum QAM modulation scheme for each tone for application in Link Dependent Adaptive Radio (LDAR).
    • 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.
    • AN ALL-DIGITAL ANTENNA CONTROL PROTOCOL

      Uetrecht, Jim; Quasonix, Inc. (International Foundation for Telemetering, 2019-10)
      For decades, analog amplitude modulation (AM) imparted by antenna feeds has served as the gold standard by which antenna control units (ACUs) manage tracking. This paper presents a digital alternative, designed to provide AM information, signal quality metrics, and additional real-time status, all over existing analog AM cables. Its benefits include reduced (and known) delay in the tracking loop, smart selection among multiple tracking receivers, and support for advanced features such as tracking through interfering signals and tracking intermittent or time-division-multiplexed transmissions.
    • 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.
    • DIRECT IMPLEMENTATION OF A BIDIRECTIONAL NETWORK COMMUNICATION LINK IN CIVIL AIRCRAFT FLIGHT TEST USING MODIFIED LTE AIR-TO-GROUND SYSTEM

      Du, Xianyu; Deng, Guobao; COMAC Flight Test Center (International Foundation for Telemetering, 2019-10)
      This paper mainly describes a preliminary trial implementation of a bidirectional network communication link for aircraft range flight test application based on modified LTE Air-to-Ground systems. The theoretical feasibility of this trial which integrated the existing on-board network-based acquisition system installed on our regional jet and a newly designed modified LTE Air-to-Ground communication system was carefully analysed and validated before system level ground experiments. Finally, several test flights were performed within a specific airspace with two eNodeBs, which configured as an independent LTE network and covered most of the designed flight path, and the test results give us the conclusion that under the promise of deploying reliable ground base stations, LTE system has the potential capability to provide acceptable bandwidth and time delay performance for range flight test application.
    • 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.
    • 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.
    • Augmenting Cybersecurity in Telemetry Post Processing Environments with Insider Threat Analysis

      Kalibjian, Jeff; Perspecta (International Foundation for Telemetering, 2019-10)
      Mature companies implement robust cybersecurity practice in their organizations by deploying a layered defense comprising many differing security tools whose functionality complements one another. Tools such as firewalls, Anti-Virus (AV), Intrusion Detection/Prevention (IDS/IPS), Data Leak Protection (DLP), and Security Information and Event Management (SIEM) can be rolled out in many combinations to create very effective cyber defenses. A general premise is that organizations are trying to keep “bad guys” out. In recent years, focus has been shifting to address the potential for malicious (insider) employees who may wish to take actions to compromise the firms they work for as an increasing number of incidents are attributed to insiders. After reviewing the insider threat landscape as well as accepted methodologies for detection; application to telemetry post processing environments will be discussed with example deployment scenarios explored.
    • Multi-Stage Attack Detection Using Layered Hidden Markov Model Intrusion Detection System

      Moazzami, Farzad; Dean, Richard; Zegeye, Wondimu K.; Morgan State University, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Intrusion Detection Systems (IDS) based on Artificial Intelligence can be deployed to protect telemetry networks against intruders. As security solutions which encrypt radio links do not accommodate the ever evolving network attacks and vulnerabilities, new defense mechanisms using machine learning and artificial intelligence can play a significant role for telemetry networks. This paper proposes a multi-layered Hidden Markov Model (HMM) IDS that addresses multi-stage attacks. This is due to the fact that intrusions are increasingly being launched through multiple phases instead of single stage intrusion. This layered model divides the problem space into smaller manageable pieces reducing the curse of dimensionality associated with HMMs. To verify the application of this model for real network, the NSL-KDD dataset is used to train and test the model.
    • CYBERDEFENSE AND DATA SECURITY IN FLIGHT TEST APPLICATIONS

      Weir, Malcolm; Ampex Data Systems Corporation (International Foundation for Telemetering, 2019-10)
      Specialist test establishments have historically placed significant reliance on “security through obscurity”. With increasing “always on” connectivity and the drive to leverage commercial products, the threat space has widened significantly while the sophistication of attack vectors has evolved. Access through vulnerabilities embedded within a platform’s communications, flight controls, or other on-board access points leave organizations vulnerable to attack, exploitation, and loss of revenue or property. Cyber and operational security associated with all aspects of aircraft technologies is becoming increasingly critical. This paper investigates techniques and procedures by which aircraft and space vehicles can be compromised by and protected against cyber-attacks.
    • TEST METHODS AND RESULTS FOR ADAPTIVE EQUALIZERS

      Hill, Terry; Quasonix (International Foundation for Telemetering, 2019-10)
      Multipath distortion has been a major source of data corruption in aeronautical telemetry signals for decades. In recent years, however, adaptive equalizers have begun to appear in telemetry receivers. These equalizers offer the promise of mitigating or even eliminating the damage done by the multipath channel, and many ranges are adopting their use. Unfortunately, there have not been any standardized tests by which to quantify the efficacy and limitations of adaptive equalizers. This paper presents a generalized test methodology for making a quantitative performance assessment of any adaptive equalizer, along with representative test results for one particular adaptive equalizer.
    • CO-EXISTENCE OF AERONAUTICAL MOBILE TELEMETRY AND LTE SYSTEMS IN THE S-BAND

      Shoudha, Shamman Noor; Saquib, Mohammad; Univ Texas, Dept Electrical Engineering (International Foundation for Telemetering, 2019-10)
      This paper analyzes the effect of Long-Term Evolution (LTE) uplink interference on the performance of Aeronautical Telemetry S-band users. A MATLAB simulation environment is used to analyze the interference effect using SOQPSK-TG and 64-QAM modulation schemes for telemetry and LTE transmitters, respectively. An ideal Surface Acoustic Wave (SAW) filter followed by a 2-by-2 symbol detector is used in the telemetry receiver. To ensure a target bit error rate (BER) of 10-5, depending on the LTE spectrum mask, the Carrier-to-Interference (C/I) ratio requirement is -15.4, -32.4 and -30 dB for data rates 1; 5 and 10 Mbits/s, respectively.
    • DUAL-CHANNEL RECEIVER PERFORMANCE USING BESTCHANNEL SELECTION: FIELD TEST RESULTS

      Uetrecht, Jim; Quasonix, Inc. (International Foundation for Telemetering, 2019-10)
      Best-Channel Selection (BCS) uses real-time data quality metrics (DQM) to select the best demodulated bits from Channel 1, Channel 2, and the Combiner of dual-channel receivers. Laboratory testing has demonstrated a substantial reduction in bit error rate (BER) relative to individual channels (including the Combiner) under some synthesized link conditions, with no degradation in BER under the remainder of tested link conditions. This paper extends those results to real-world flight tests.
    • 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.
    • RESILIENT PNT / TSPI ALTERNATIVE SOLUTIONS FOR TELEMETRY DURING GNSS OUTAGE TEST SCENARIOS

      Fischer, John; Perdue, Lisa; Orolia (International Foundation for Telemetering, 2019-10)
      GNSS is key to effective situational awareness, providing critical Positioning, Navigation and Timing (PNT) telemetry data for mobile military operations. Yet GPS/GNSS jamming and spoofing attacks are on the rise. The combination of low-cost hardware, open source software, and tutorials on YouTube have fostered the proliferation of these malicious acts. Beyond intentional disruption, other factors such as environmental conditions and conflicts with other electronic systems can result in unreliable or even unavailable GNSS data. The disruption of GNSS for increasing periods of time through jamming/spoofing must now be an essential test component in most test scenarios today. How can one still provide reliable Time-Space Position Information (TSPI) during periods of GNSS denial? Key mobile military operations that rely on continuous and trusted PNT telemetry data from GNSS include: SatCom on the Move (SOTM), Command, Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance (C4ISR), Airborne Communications Relay, Synthetic Aperture Radar, and Combat Search and Rescue (CSAR). Techniques and technologies used in battlefield systems to provide alternative sources of PNT data during a GNSS outage, can also be used on the test range. This paper will identify technologies, best practices and strategies for GNSS jamming/spoofing detection and protection systems and testing protocols to maintain a state of PNT readiness.
    • AN APPROACH FOR BER DETERMINATION USING LOGGED AERONAUTICAL TELEMETRY DATA

      Tamakuwala, Jimmy B.; Sonar, Souvik; Jena, Avijit; Integrated Test Range, DRDO Chandipur; Defense Research and Development Organization (International Foundation for Telemetering, 2019-10)
      BER is regarded as the link-performance metric in a digital communication system. It is a function of Eb/N0 and is dependent on the modulation scheme used. This relation is often used in prediction of ground telemetry systems performance for a mission configuration. However, there is no objective way of comparing the post flight results, as BER measurement in a flight test is not practically feasible for want of transmitting sufficient reference bit patterns. In this paper, an indirect way of computing BER and, in turn, link Eb/N0 is proposed for a PCM/FM link based on the frame synchronised data logged by the ground telemetry equipment. Using known quantities like bit rate and frame rate, a quantity defined as frame loss rate is computed. Applying the relations between frame loss probability, frame sync pattern and SFID information in the PCM format, an approach for bit error probability is demonstrated based on field data. By using a sliding window over a fixed length of data, BER for the entire flight duration can be determined as a function of flight time with the step size of the length of data window.
    • STANDARDIZED NETWORKED TELEMETRY USING EXISTING COTS RADIO MODULES - IpoTm

      O’Connell, Ray; RoboComAI (International Foundation for Telemetering, 2019-10)
      The T&E ranges require two-way networked communications to provide gains in critical areas including: test efficiency, safety, cost savings and spectrum efficiency. The development of a network compatibility module which can accommodate networked telemetry standards while using existing COTS transmitter and receiver components has multiple benefits to the T&E test community. This component based approach to networked telemetry has the additional benefit of allowing new technology to be readily adopted for networking applications. This paper reviews the progress made in the development of a standardized component based networking telemetry capability as well as other networked telemetry radio systems.
    • Testing the Reliability and Flexibility of Digitizers adapting the RF/IF signals over IP applications using a testbed Platform.

      Gonzalez, Virgilio; Sandoval, Jose Carlos; Elahi, Mirza; Corral, Pabel; Yasuda, Susumu; Univ Texas, Dept Electrical and Computer Engineering; White Sands Missile Range, U.S. Army Test and Evaluation Command (International Foundation for Telemetering, 2019-10)
      Many disadvantages from physical limitations in RF Telemetry can now be eliminated using RF over IP Networks. Digitizers mitigate the problem of signal degradation that RF has due to physical restrictions and provide reliability and flexibility to the signal. The digitizers are also able to preserve both frequency and timing characteristics, and then accurately reconstructing the original Telemetry signals to enable processing, recording or retransmission at another location. The digitizers along with the software-defined radios forms a flexible testbed platform which enables us to simulate both communication systems to qualify and quantify their behavior, while studying the interference between systems. In addition, quantization of noise is a critical parameter to determine the bit error rate in the testbed. Digitizers can be configured at a certain bandwidth and additional gain, in order to make this layer almost a transparent transmission.