• Capacity Enhancement in Aeronautical Channels by MIMO Technology

      Cole-Rhodes, Arlene; Moazzami, Farzad; Morgan State University (International Foundation for Telemetering, 2011-10)
      This paper shows how the application of MIMO (multiple-input multiple-output) communication methods can enhance telemetry systems. The main contribution of MIMO to the communication systems is improving spectral efficiency by exploiting spatial diversity of multiple antennas. For communications using high order QAM modulated signals, a blind MIMO equalizer is proposed in earlier works. In this work the possibility of adapting blind MIMO equalizer to iNET problems is explored. In addition, MIMO equalization is adapted to operate as a successive interference cancellation (SIC) scheme to improve the quality of received signal in a high interference environment by capturing and cancelling the interferer.
    • Detect Sense and Avoid Radar for UAV Avionics Telemetry

      Allen, Chris; Leuschen, Carl; Seybert, Audrey; Fuller, Jay; Townley, Bryan; University of Kansas (International Foundation for Telemetering, 2011-10)
      This paper describes the development and test results of a Frequency Modulated Continuous Wave (FMCW) L-Band radar testbed designed to detect obstacles in the proximity of an Unmanned Aerial Vehicle (UAV). From laboratory loopback tests, it was calculated that with pulse compression and a transmit power of 150 mW (22 dBm), the radar is capable of detecting an object with a 0.014-m2 radar cross-sectional area at ranges between 500 ft to 1 mi. Analysis shows that post processing of the collected data would reveal information about the obstacle such as its range and location relative to the aircraft. Design and testing procedures are discussed.
    • High Performance S and C-Band Autotrack Antenna

      Lewis, Ray; ViaSat, Inc. (International Foundation for Telemetering, 2011-10)
      A novel dual-band S and C band antenna for high-performance autotracking applications is described. The antenna provides simultaneous dual band coverage for targets with circular or linear polarization. A vertex mounted C-band multi-mode common aperture feed is added in a Cassegrain configuration augmenting the existing ViaSat patented [1-4] ESCAN® S-band prime focus feed. A dichroic subreflector is also added allowing simultaneous dual band operation for the prime focus and Cassegrain configurations with minimal interaction. Existing S-band antennas are easily upgraded for dual band capability with only the additions of the vertex mounted C-band feed and dichroic subreflector.
    • Use of Multi-Threading, Modern Programming Language, and Lossless Compression in a Dynamic Commutation/Decommutation System

      Wigent, Mark A.; Mazzario, Andrea M.; Matsumura, Scott M.; SAIC; Kauai Software Solutions (International Foundation for Telemetering, 2011-10)
      The Spectrum Efficient Technology Science and Technology (SET S&T) Program is sponsoring the development of the Dynamic Commutation and Decommutation System (DCDS), which optimizes telemetry data transmission in real time. The goal of DCDS is to improve spectrum efficiency - not through improving RF techniques but rather through changing and optimizing contents of the telemetry stream during system test. By allowing the addition of new parameters to the telemetered stream at any point during system test, DCDS removes the need to transmit measured data unless it is actually needed on the ground. When compared to serial streaming telemetry, real time re-formatting of the telemetry stream does require additional processing onboard the test article. DCDS leverages advances in microprocessor technology to perform this processing while meeting size, weight, and power constraints of the test environment. Performance gains of the system have been achieved by significant multi-threading of the application, allowing it to run on modern multi-core processors. Two other enhancing technologies incorporated into DCDS are the Java programming language and lossless compression.
    • The Performance of Simple Receivers for MIMO SOQPSK-TG Systems

      Sahin, Cenk; University of Kansas (International Foundation for Telemetering, 2011-10)
      We investigate the performance of reduced complexity receivers for aeronautical telemetry shaped-offset quadrature phase shift-keying (SOQPSK-TG) in multiple-input multiple-output (MIMO) channels. We use spatial multiplexing (SM) to achieve the highest throughput possible. Two types of channel equalization methods are considered to separate the substreams sent by independent antennas. The first method employs linear equalizers, including minimum mean-squared error (MMSE) and zero-forcing (ZF), to nullify the intersymbol interference (ISI) introduced by the MIMO channel in a single step. The second method, vertical Bell Labs layered space time (V-BLAST) architecture, removes the ISI iteratively by the use of decision feedback (DE). The channel equalizer is followed by a suboptimal SOQPSK-TG detector. The performance of various equalizer/detector pairs are presented. The results show that computationally efficient MIMO SOQPSK-TG architectures achieve excellent bit error rate (BER) performance while transmitting at high data rates.
    • The Effects of Phase Noise on Trellis FM & SOQPSK Data Links

      O'Cull, Douglas C.; Systems Engineering & Management Company (SEMCO) (International Foundation for Telemetering, 2011-10)
      Current IRIG standards provide guidelines for system phase noise and several manufactures provide receivers and transmitters that perform within this standard. However, legacy receivers and transmitters that do not meet the current IRIG standards are sometimes still used during a mission. This paper will address how phase noise outside of the current IRIG standard affects the performance of an FM data link when using a trellis demodulator, as well as the performance of an SOQPSK data link in a high phase noise environment. Bit error rate performance and test results at several different rates with various phase noise masks are presented in this paper.
    • Research About the Efficient Recording Structure of Installed Data Recording Devices

      Lee, Hyun-Kyu; Lee, Hyun-So; Song, Jae-Hoon; Danamsystems Inc.; Korea Aerospace Research Institute (KARI) (International Foundation for Telemetering, 2011-10)
      Although the wireless data transmission technologies have evolved significantly, data recording devices are still being used because of the limitations of data rates and reliability issues over wireless environment in the avionics, military, space etc. Payload has limitation of weight. In addition, storage has limitation of capacity. So, we need to research about a data recording structure within a limited amount of memory. In this paper, we propose a new data recording structure through a condition necessary for efficient use of memory. The proposed structure has an equivalent function as other recording systems. But, it uses less memory than the other equivalent recording structures.
    • Implementation of an iNET-Enabled End-Node Utilizing an MDL-Based Telemetry System Architecture

      Yin, Xianghong; Sulewski, Joe; L-3 Telemetry East (International Foundation for Telemetering, 2011-10)
      Today's telemetry systems need to be highly configurable and easily extensible to support a constantly growing number of data acquisition/transmitting components from different manufacturers. One way to achieve this goal is through a standardized descriptive language that can define the system structure as well as end-node devices. The integrated Network Enhanced Telemetry (iNET) program has explored such a possibility by creating a series of standards to define how devices are configured and interoperate with each other. As one of the standards created by the iNET program, the Metadata Description Language (MDL) specifies a common interchange language that defines and configures a Telemetry Network System (TmNS). MDL Instance Documents are used to exchange test requirements, data formats and configuration information among the devices within a TmNS system. MDL, together with other standards created in the iNET program, serve as a foundation for assembling a modern telemetry system. This paper starts with an overview of the MDL-based system description architecture. A typical configuration workflow of an MDL-based system is then described. iNET functionality implementations for new and legacy devices are used as examples to illustrate the power of MDL-based design, as well as the challenges and issues associated with the implementation of the MDL standard. We explain and evaluate the design decisions for a new product, the L-3 NetDAS Recorder, as the case study. We also discuss how a legacy Data Acquisition Unit (DAU) acting as an LTC Data Source Unit can be updated to support MDL based iNET functionality. Our practice shows that more efficient data acquisition systems can be designed and implemented using the metadata definition language as a core tool for equipment and system description. We conclude the paper with design tradeoffs and discussions.
    • Design Considerations for a Launch Vehicle Development Flight Instrumentation System

      Johnson, Martin L.; Crawford, Kevin; Marshall Space Flight Center (International Foundation for Telemetering, 2011-10)
      When embarking into the design of a new launch vehicle, engineering models of expected vehicle performance are always generated. While many models are well established and understood, some models contain design features that are only marginally known. Unfortunately, these analytical models produce uncertainties in design margins. The best way to answer these analytical issues is with vehicle level testing. The National Aeronautics and Space Administration respond to these uncertainties by using a vehicle level system called the Development Flight Instrumentation, or DFI. This DFI system can be simple to implement, with only a few measurements, or it may be a sophisticated system with hundreds of measurement and video, without a recording capability. From experience with DFI systems, DFI never goes away. The system is renamed and allowed to continue, in most cases. Proper system design can aid the transition to future data requirements. This paper will discuss design features that need to be considered when developing a DFI system for a launch vehicle. It will briefly review the data acquisition units, sensors, multiplexers and recorders, telemetry components and harnessing. It will present a reasonable set of requirements which should be implemented in the beginning of the program in order to start the design. It will discuss a simplistic DFI architecture that could be the basis for the next NASA launch vehicle. This will be followed by a discussion of the "experiences gained" from a past DFI system implementation, such as the very successful Ares I-X test flight. Application of these design considerations may not work for every situation, but they may direct a path toward success or at least make one pause and ask the right questions.
    • Stopping Launch Vehicle Failures Using Telemetry to Measure Equipment Usable Life

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2011-10)
      Launch vehicle equipment reliability is driven by infant mortality failures, which can be eliminated using a prognostic analysis prior, during and/or after the exhaustive and comprehensive dynamic environmental factory acceptance testing. Measuring and confirming equipment performance is completed to increase equipment reliability by identifying equipment that fails during test for repair/replacement. To move to the 100% reliability domain, equipment dynamic environmental factory testing should be followed by a prognostic analysis to measure equipment usable life and identify the equipment that will fail prematurely. During equipment testing, only equipment performance is measured and equipment performance is unrelated to equipment reliability making testing alone inadequate to produce equipment with 100% reliability. A prognostic analysis converts performance measurements into an invasive usable life measurement by sharing test data used to measure equipment performance. Performance data is converted to usable life data provides a time-to-failure (TTF) in minutes/hours/days/months for equipment that will fail within the first year of use, allowing the production of equipment with 100% reliability.
    • Wireless Rotor Data Acquisition System

      Kpodzo, Elias; DiLemmo, Marc; Wang, Wearn-Juhn; L-3 Communications Telemetry East (International Foundation for Telemetering, 2011-10)
      Flight test data acquisition systems have been widely deployed in helicopter certification programs for a few decades. A data acquisition system uses a series of strategically placed sensors to provide instantaneous status condition of the helicopter's components and structure. However, until recently, it has been difficult to collect flight test data from helicopter rotors in motion. Traditional rotor solutions have used slip rings to electrically connect fixed and rotating mechanical elements; but slip rings are inconvenient to use, prone to wear, and notoriously unreliable.
    • Realization of Fast Acquisition for Spread Spectrum Signal Based on FFT

      Jian-zhong, Qi; Yan, Gong; Peng, Song; North China University of Technology (International Foundation for Telemetering, 2011-10)
      Acquisition based on Fast Fourier Transform (FFT) can acquire Pseudo-random code phase quickly and improve the performance of the satellite navigation receivers. In the paper Real-time receiver adopts the FPGA to realize the function of FFT and uses DSP processor to control the implementation process of Acquisition. For increasing the sensitivity of Acquisition incoherent accumulation were used in the process. Also, in the paper we have discussed the process method for decreasing the negative influence of signal power changes and carrier's Doppler frequency.
    • Development of a Subminiature Enhanced Flight Termination Receiver

      Woodard, Tracy; Vetter, Jeff; Rodzinak, Jason; Eglin Air Force Base; L-3 Communications Cincinnati Electronics (International Foundation for Telemetering, 2011-10)
      As the size of missiles and UAVs shrink, so does the volume available for the Flight Termination System (FTS). Small, light weight FTS systems open up applications not possible with the larger and heavier conventional FTS systems. This paper presents a novel approach for the design, implementation and test of a subminiature Flight Terminate System Receiver for use in the Subminiature Flight Safety System (SFSS). This receiver implements the new digital-based Enhanced Flight Termination System (EFTS) protocol, while maintaining a volume of less than 1 cubic inch with power consumption of less than 2 watts. Combining all of the necessary functionality into a small package while meeting the rigorous requirements of the Range Commanders Council (RCC) specifications (EMI, vibration and shock) presented significant challenges. The Subminiature Enhanced Flight Termination Receiver used in the SFSS has been named the "SEFTR".
    • Remote-Sensed LIDAR Using Random Sampling and Sparse Reconstruction

      Creusere, Charles D.; Martinez, Juan Enrique Castorera; New Mexico State University (International Foundation for Telemetering, 2011-10)
      In this paper, we propose a new, low complexity approach for the design of laser radar (LIDAR) systems for use in applications in which the system is wirelessly transmitting its data from a remote location back to a command center for reconstruction and viewing. Specifically, the proposed system collects random samples in different portions of the scene, and the density of sampling is controlled by the local scene complexity. The range samples are transmitted as they are acquired through a wireless communications link to a command center and a constrained absolute-error optimization procedure of the type commonly used for compressive sensing/sampling is applied. The key difficulty in the proposed approach is estimating the local scene complexity without densely sampling the scene and thus increasing the complexity of the LIDAR front end. We show here using simulated data that the complexity of the scene can be accurately estimated from the return pulse shape using a finite moments approach. Furthermore, we find that such complexity estimates correspond strongly to the surface reconstruction error that is achieved using the constrained optimization algorithm with a given number of samples.
    • Control System Analysis of a Telemetry Network System (TmNS)

      Araujo, Maria S.; Moodie, Myron L.; Abbott, Ben A.; Grace, Thomas B.; Southwest Research Institute; Naval Air Systems Command (NAVAIR) (International Foundation for Telemetering, 2011-10)
      On the surface, network-based telemetry systems would appear to be simple, stateless, information collecting entities. Unfortunately, the reality of networking technologies brings a hierarchy of control loops into the system setup. At the top level, the command and status collection data loop that users manipulate the system with is a feedback loop. The commands themselves are transmitted across the network through competing streams of data, which are guided and controlled by Transmission Control Protocol (TCP) mechanisms. TCP mechanisms themselves have control loops in order to avoid congestion, provide reliability, and generally optimize flow. These TCP streams flowing across a network fabric compete at choke points, such as network switches, routers, and wireless telemetry links - all of which are also guided by control loops. This paper discusses the hierarchy of control loops present in a TmNS, provides an analysis of how these loops interact, and describes key points to be considered for telemetry systems.
    • Remote Imaging System Acquisition Multispectral Imager

      Grubbs, Elmer; Marcellin, Michael; Choate, Laura; Lundstrom, Kevin; Pounds, Kevin; Richards, Garrett; Vinal, Eli; University of Arizona (International Foundation for Telemetering, 2011-10)
      The National Aeronautics and Space Administration's (NASA) Remote Imaging System Acquisition (RISA) camera will integrate the functionalities of existing space cameras. The system operates between 350nm and 1050nm wavelengths, with a MATLAB user interface, uses a CS-mount standard with a CMOS detector, and has a fixed focal plane. The implementation of a liquid lens uses electrical focus adjustments to image from infinity down to one foot. This will allow wireless operation and reduces mechanical failure. All images and video captured will be transmitted wirelessly to a MATLAB program. This data is then processed and stored, allowing for remote imaging.
    • Complete Vendor-Neutral Instrumentation Configuration with IHAL and TMATS XML

      Hamilton, John; Darr, Timothy; Fernandes, Ronald; Sulewski, Joe; Jones, Charles; Knowledge Based Systems, Inc.; L-3 Telemetry East; Edwards Air Force Base (International Foundation for Telemetering, 2011-10)
      Previously, we have presented an approach to achieving standards-based multi-vendor hardware configuration using the Instrumentation Hardware Abstraction Language (IHAL) and an associated Application Programming Interface (API) specification. In this paper, we extend this approach to include support for configuring PCM formats. This capability is an appropriate fit for IHAL since changes to hardware settings can affect the current telemetry format and vice versa. We describe extensions made to the IHAL API in order to support this capability. Additionally, we show how complete instrumentation configurations can be described using an integrated IHAL and TMATS XML. Finally, we describe a demonstration of this capability implemented for data acquisition hardware produced by L-3 Telemetry East.
    • Using Analog Telemetry to Measure Equipment Mission Life and Upgrade Factory Equipment ATP

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2011-10)
      For equipment and systems that are too expensive and too important to fail such as launch vehicles and spacecraft, the actual reliability is dominated by infant mortality failures that occur soon after dynamic environmental ATP that is used to eliminate the equipment that will fail prematurely. Premature equipment failures greatly increase risk getting to space and working in space, slowing down the growth of commercial space tourism. Premature equipment failures occur because during factory ATP, only equipment performance is measured and there is no relationship between equipment performance and equipment reliability. Accelerated aging was documented preceding GPS satellite atomic clock failures during the 10 years of the GPS Block I test and evaluation phase. Prognostic technology leverages the presence of accelerated aging to identify equipment that will fail. A prognostic analysis uses the same prognostic algorithms to convert equipment telemetry used to measure equipment performance to a time-to-failure (TTF) measurement, previously made using a probability distribution function. The equipment with accelerated aging that is present after ATP can be replaced, stopping infant mortality failures from occurring and producing equipment with 100% reliability. When all spacecraft and launch vehicle equipment that will fail prematurely are identified and replaced, satellite and launch vehicle reliability will be 100% and getting to space and working in space will be much safer.
    • Cost Effective COTS Microphone Array for Range Safety Applications

      Kosbar, Kurt; Goodlin, Ryan; Grafelman, Brad; Wolz, Troy; Missouri University of Science and Technology (International Foundation for Telemetering, 2011-10)
      In range safety and surveillance applications, it is helpful to have an array of sensitive, directional microphones. Using beamforming and feature extraction, one can use such an array to locate, track, and identify a variety of targets. This paper describes how one can construct such an array from sub-arrays of small, inexpensive, commercial off-the-shelf microphones. Each sub-array consists of a few dozen electrets condenser microphones which are closely spaced. The analog signals from the microphones are summed, digitized, and then combined with signals from other sub-arrays using a field programmable gate array device. The digital signal is then passed to a general purpose computer for further analysis.
    • The Subminiature Flight Safety System

      Woodard, Tracy; Dehmelt, Chris; Eglin Air Force Base; L-3 Communications Telemetry East (International Foundation for Telemetering, 2011-10)
      Weapons platform testing and monitoring have historically consisted of custom telemetry and flight safety system solutions tailored to the requirements (including Title 10 Mandates) and size constraints of individual platforms. The size of these individual components of these systems has necessitated that warhead replacement to facilitate insertion of these units to support test and evaluation activities. Currently there are no products available to meet these requirements in a miniaturized and modular package. L-3 Communications Telemetry East (L-3 TE) has developed an extensive background in providing solutions to gather vital missile and target information over the last several decades. Under the auspices of Eglin AFB, L-3 TE is leading a multi-disciplinary team to design and develop the Subminiature Flight Safety System (SFSS) to support existing and new weapons applications. SFSS is a universal, small, and low cost redundant flight termination system (FTS) that incorporates encoding, processing and TSPI capacities that provides critical health/safety/welfare monitoring and allows for highly efficient telemetering of all weapon application and FTS data. The SFSS is intended as a solution to allow weapon system developers, test agencies, and range safety officers the ability to track, monitor, and if necessary, terminate all types of weapon systems. It is designed to interface with newly developed weapon systems, while providing backward compatibility to meet existing requirements with minimal modifications to the weapon. The SFSS components are intended to significantly reduce the cost and improve the quality of test support by providing a highly integrated solution that minimizes physical intrusion into weapon systems, by eliminating the need for warhead removal. In addition, a common hardware platform will reduce overall system cost of acquisition and maintenance to the government, a key element in today's world of stressed budgets.