Lee, Jung Kyu; De Flaviis, Franco; University of California, Irvine (International Foundation for Telemetering, 2006-10)
      In this paper, we propose a dual-band switched beam system operating at 4.05 and 7.4 GHz. This system comprise of a dual frequency Butler matrix feeding a microstrip antenna array. Very good agreement is shown between measured and simulated data. The system can provide a tilted beam of ±13° and ±48° at the lowest frequency band and ±9° and ±27° at the higher frequency band.

      Saquib, Mohammad; Popescu, Otilia; Popescu, Dimitrie C.; Rice, Michael; University of Texas; Brigham Young University (International Foundation for Telemetering, 2006-10)
      In this paper we describe a new method that is applicable to mitigating both multipath interference and adjacent channel interference (ACI) in aeronautical telemetry applications using ARTM Tier-1 waveforms. The proposed method uses a linear equalizer that is derived using Kalman filtering theory, which has been used for channel equalization for high-speed communication systems. We illustrate the proposed method with numerical examples obtained from simulations that show the bit error rate performance (BER) for different modulation schemes.

      Berdugo, Albert; Hildin, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      Airborne data acquisition systems have changed very little over the years. Their growth has primarily been in the area of digital filtering and the acquisition of new avionic busses. Communication between data acquisition units operating as a system still employs Time Division Multiplexing scheme. These schemes utilize command and data busses like CAIS and PCM. Although this approach is highly efficient, it has many drawbacks. These drawbacks have resulted in rigid system architecture, system bandwidth limitations, highly specialized recorders to acquire unique avionic busses that would otherwise overwhelm the system bandwidth, and unidirectional flow of data and control. This paper describes a network centric data acquisition system that is Ethernet based. Although Ethernet is known as an asynchronous bus, the paper will describe a deterministic time distribution over the bus per IEEE-1588 that allows the use of a packet network for airborne data acquisition. The acquisition unit within the network system is defined by its MIB (Management Information Base) and operates as a data source unit. Other network components may operate as a data sink unit, such as recorders, or as a data source and sink. The role of different units in the network system will be evaluated. The paper will also describe network gateways that allow the use of traditional PCM systems with a network-based system.

      Grim, Evan T.; Southwest Research Institute (International Foundation for Telemetering, 2006-10)
      Network-centric data acquisition and telemetry systems continue to gain momentum and adoption. However, inherent non-deterministic network delays hinder these systems’ suitability for use where high-accuracy timing information is required. The emerging IEEE 1588 standard for time distribution offers the potential for real-time data acquisition system development using cost-effective, standards-based network technologies such as Ethernet and IP multicast. This paper discusses the challenges, realities, lessons, and triumphs experienced using IEEE 1588 in the development and implementation of such a large-scale network-centric data acquisition and telemetry system. IEEE 1588 clears a major hurdle in moving the network-centric buzz from theory to realization.
    • International Telemetering Conference Proceedings, Volume 42 (2006)

      International Foundation for Telemetering, 2006-10

      Tian, Hai; Trojak, Tom; Jones, Charles H.; Teletronics Technology Corporation; Edwards Air Force Base (International Foundation for Telemetering, 2006-10)
      This paper presents a practical implementation of a hardware design for transmission of data over aircraft power lines. The intent of such hardware is to significantly reduce the wiring in the aircraft instrumentation system. The potential usages of this technology include pulse code modulation (PCM), Ethernet and other forms data communications. Details of the fieldprogrammable gate array (FPGA) and printed circuit board (PCB) designs of the digital and analog front end will be discussed. The power line is not designed for data transmission. It contains considerable noise, multipath effects, and time varying impedance. Spectral analysis data of an aircraft is presented to indicate the difficulty of the problem at hand. A robust modulation is required to overcome the harsh environment and to provide reliable transmission. Orthogonal frequency division multiplexing (OFDM) has been used in power line communication industry with a great deal of success. OFDM has been deemed the most appropriate technology for high-speed data transmission on aircraft power lines. Additionally, forward error correction (FEC) techniques are discussed.
    • Best Source Selection on Encrypted Data

      Guadiana, Juan M.; White Sands Missile Range (International Foundation for Telemetering, 2006-10)
      The size of the range at White Sands means multiple acquisition sites are needed to properly cover a typical vehicle trajectory. As vehicle complexity increase, the need for robust acquisition grows. Multiple acquisition sites are needed to provide as complete coverage as practical. Space Diversity combining would provide a single composite source for all the displays and recording, but this is not practical due to the large distances between acquisition sites. Instead a composite is made from the various sites by correlation on non-encrypted (or decrypted) data. The previous best source selector, a frame synch histogrammer, could produce encrypted and decrypted composites. Some of our customers have missed the encrypted composites, hence the subject is revisited to encourage development. This paper reviews post decryption correlation and then focuses on correlating on encrypted data. The encryption serves to eliminate the ambiguities that are inherent in decrypted (nonencrypted) signals. So, it may be possible to accomplish this with a small correlator. The expected performance would be similar to that of correlated composites on decrypted or unencrypted data. The typical configuration would be considerably smaller as well since only two decrypters would be needed. One decrypter alone would be insufficient and could not resolve the case where only one site has data and the remaining sites have noise. When there is no correlation the correct site cannot be resolved. Testing these compositing methods is also discussed, as a good test method also provides insight on how the compositor should work.
    • XidML – Two Years On

      Corry, Diarmuid; Acra Control Inc. (International Foundation for Telemetering, 2006-10)
      In 2004 ACRA CONTROL introduced XidML as a published standard for instrumentation definition via XML. After two years in the field, much feedback and two revisions, this paper outlines where the standard is now, some of the lessons learned and discusses some ideas for where next. XidML allows any package, message or frame to be defined including PCM, MIL-STD- 1553, Ethernet and storage formats, it is also used to define the settings for instrumentation as diverse as Analog to Digital modules, MIL-STD-1553 monitors, PCM encoders, recorders, bit-syncs, and decoms. Importantly it facilitates the EU range and data format to be defined for large parameter lists. The key elements in the standard are discussed along with some lessons learned.

      Rice, Michael; Nelson, Tom; Brigham Young University (International Foundation for Telemetering, 2006-10)
      The optimum detector for shaped offset QPSK (SOQPSK) is a trellis detector which has high complexity (as measured by the number of detection filters and trellis states) due to the memory inherent in this modulation. In this paper we exploit the cross-correlated, trellis-coded, quadrature modulation (XTCQM) representation of SOQPSK-TG to formulate a reduced complexity detector. We show that a factor of 128 reduction in the number of trellis states of the detector can be achieved with a loss of only 0.2 dB in bit error rate performance as compared to optimum at P(b) = 10^(-5).

      Graul, Michael; Fernandes, Ronald; Hamilton, John L.; Jones, Charles H.; Morgan, Jon; Knowledge Based Systems, Inc; Edwards Air Force Base (International Foundation for Telemetering, 2006-10)
      This paper presents the description of the updated Data Display Markup Language (DDML), a neutral format for data display configurations. The development of DDML is motivated by the fact that in joint service program systems, there is a critical need for common data displays to support distributed T&E missions, irrespective of the test location, data acquisition system, and display system. DDML enables standard data displays to be specified for any given system under test, irrespective of the display vendor or system in which they will be implemented. The version 3.0 of DDML represents a more mature language than the version 1.0 presented at the 2003 ITC. The updated version has been validated for completeness and robustness by developing translators between DDML and numerous vendor formats. The DDML schema has been presented to the Range Commander’s Council (RCC) Data Multiplex Committee for consideration for inclusion in the IRIG 106 standard. The DDML model will be described in terms of both the XML schema and the UML model, and various examples of DDML models will be presented. The intent of this paper is to solicit specific input from the community on this potential RCC standard.

      Hicks, William T.; IMET Corporation (International Foundation for Telemetering, 2006-10)
      Most modern digital filtering is done by taking the average (mean) of a signal or some weighted average. Another method is to use feedback, which more closely resembles how analog filters with feedback operate. In the case of low pass filters, all these methods tend to give a trade off in getting the signal to pass while attenuating the higher frequency noise. An alternative is to use a median filter, which selects the mid value of a group of points. While this is not as computationally simple as other filters, it allows for the attenuation of noise while allowing sudden changes in signal level to pass thru unaltered. This paper discusses the characteristics of median filters and methods of implementing them.

      Wickert, Mark; Samad, Shaheen; Butler, Bryan; University of Colorado at Colorado Springs; Real-Time Logic Inc. (International Foundation for Telemetering, 2006-10)
      Many satellite payloads require wide-band channels for transmission of large amounts of data to users on the ground. These channels typically have substantial distortions, including bandlimiting distortions and high power amplifier (HPA) nonlinearities that cause substantial degradation of bit error rate performance compared to additive white Gaussian noise (AWGN) scenarios. An adaptive equalization algorithm has been selected as the solution to improving bit error rate performance in the presence of these channel distortions. This paper describes the design and implementation of an adaptive baseband equalizer (ABBE) utilizing the latest FPGA technology. Implementation of the design was arrived at by first constructing a high fidelity channel simulation model, which incorporates worst-case signal impairments over the entire data link. All of the modem digital signal processing functions, including multirate carrier and symbol synchronization, are modeled, in addition to the adaptive complex baseband equalizer. Different feedback and feed-forward tap combinations are considered as part of the design optimization.

      Hildin, John; Arias, Sergio; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      Today’s data acquisition systems are typically comprised of data collectors connected to multiplexers via serial, point-to-point links. Data flows upstream from the sensors or avionics buses to the data acquisition units, to the multiplexer and finally to the recorder or telemetry transmitter. In a networked data acquisition system, data is transported through the network “cloud”. At the core of the network “cloud” is the network switch. The switch is responsible for distributing and directing data within the network. Network switches are commonplace in the commercial realm. Many businesses today could not function without them. A network-based data acquisition system, however, places additional burdens on the network switch. As in a commercial network, the switch in a data acquisition system must be able to distribute data packets within the network. In addition, it must be able to perform in a harsh environment, occupy a minimal amount of space, operate with limited or no external cooling, be configurable, and deal with the distribution of time information. This paper describes the required features of a ruggedized network switch and the implementation challenges facing its design. As a core component of a network-based data acquisition system, an ideal switch must be capable of operating in a large number of configurations, transporting and aggregating data between data sources and data sinks, with a mixture of devices operating at rates ranging from a few thousand bits per second to several gigabits per second, over twisted pair or fiber optic links. To ensure time coherency, the switch must also facilitate a time distribution mechanism, e.g., IEEE-1588 Precision Time Protocol (PTP). The gigabit switch described here uses the PTP to implement an end-to-end clock synchronization, for distributed acquisition nodes, to within 300 nanoseconds.

      Roach, John; Hildin, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      Traditionally, acquired instrumentation data on a non-destructive test article is recorded to a nonvolatile memory recorder. The data acquisition system usually samples and formats its inputs before transmitting the data to the recorder (also known in this paper as a data sink) via a PCM serial data stream (i.e., clock and data). In a network-based data acquisition architecture, the inclusion of an IP-based recorder adds a new dimension to the data acquisition process. Any IP network inherently allows for the bi-directional exchange of data. In this environment, the IPbased recorder can be treated as both a data sink for parameter recording and a data source for parameter extraction, data rate statistics, and recorder status reporting. The network model recasts the data recorder’s function as a file server to which multiple clients could be simultaneously requesting services. Those clients that represent the data acquisition nodes are requesting storage of their acquired parameters. Clients, such as transmitters or test engineers, are requesting access to archived data or status information for further processing. This paper presents the advantages of using an IP-based recorder in a network-based data acquisition system. The availability of an IP interface along with the intelligence built into the recorder expands its capabilities beyond that of a conventional PCM recorder. These capabilities include real-time health monitoring, support for the Simple Network Management Protocol (SNMP), data mining, reporting of real-time performance and network statistics.

      Lockard, Michael T.; Garling, James A. Jr; EMC Corporation, Solutions Engineering Group (International Foundation for Telemetering, 2006-10)
      The quantity and types of measurements and measurement instrumentation required for a test are growing. This paper describes a methodology to define and program multi-vendor instrumentation using abstraction models in a database that allows new instrumentation to be defined rapidly. This allows users to support multiple vendors’ systems while using a common user interface to define instrumentation networks, bus catalogs, measurements, pulse code modulated (PCM) formats, and data processing requirements.

      Clark, Nicholas; Dunne, Fiona; Lee, Michael; Lee, Hua; University of California, Santa Barbara (International Foundation for Telemetering, 2006-10)
      This paper describes the concept of wide-angle coverage optical vision system integrated with guidance support of microwave or acoustical imaging arrays. The objective is to provide the capability of effective high-resolution full-view monitoring and sensing. The optical component, formed by a multi-camera array, is responsible for the main interface with human users. The acoustical and microwave arrays are integrated, allowing the system to function in the event-triggered modality for optimal efficiency. In this paper, the arrays discussed are in circular configurations. With minor modification, the system can also function with linear array configurations.

      McWhorter, Mark; Honeywell Aerospace Electronic Systems (International Foundation for Telemetering, 2006-10)
      This paper discusses the effect of vehicle exhaust plasma/plume on the ability to receive telemetered data via an S-band RF link. The data presented herein were captured during the launch of the STARS FT-04-1 on February 23, 2006 from Kodiak Launch Center, Kodiak, Alaska using Alaska Aerospace Development Corporation’s (AADC) Range Safety and Telemetry System (RSTS), designed and integrated by Honeywell.

      Doonan, Daniel; Fu, Tricia; Utley, Chris; Iltis, Ronald; Kastner, Ryan; Lee, Hua; University of California, Santa Barbara (International Foundation for Telemetering, 2006-10)
      This paper describes the design and successful development of an acoustic modem for potential use in underwater ecological sensor networks. The presentation includes theoretical study, design and development of both software and hardware, laboratory experiments, full-scale field tests, and the documentation and analysis of field-test results.

      Andzik, Rob; Brans, Charles (Chuck) N.; RT Logic Inc. (International Foundation for Telemetering, 2006-10)
      Today Ranges are faced with the typical dilemma of doing more with less—less money, less time, and less experienced range personnel. Meanwhile, Ranges are being forced to make their operations more efficient in use of time, money, and functionality. As a result, Ranges are looking for automated ways to remotely configure and operate their tracking stations and to provide interoperability between ranges, sites, and equipment. RT Logic worked with numerous range operators and equipment vendors to create an open software architecture that provides rapid device configuration, equipment status at a glance, and automatic fault detection and isolation. RT Logic’s architecture utilizes the CORBA specification to achieve extensibility and scalability for future range requirements. Adoption of this architecture and approach will reduce costs, time, and mistakes.

      Chaildin, Mark; Inter-Coastal Electronics (International Foundation for Telemetering, 2006-10)
      For several decades, the military has used the Multiple Integrated Laser Engagement System (MILES) with a series of iR sensors along a belt fastened to a vehicle for training and simulation. Now, an alternative to this legacy system, a solar rechargeable battery powered wireless IR sensor is replacing wired sensors. The use of short-range RF communications network, allows the MILES sensors strategic placement about a combat vehicle without the umbilical cabling normally required for power and signal coupling from the players processing unit. The RF network operates in the 340 to 380 MHz band, has channeling capability of over 1600 channels, and coexists with the vehicles on board high-powered radios without interference. The wireless sensor implements a custom designed IR sensing amplifier, designed for maximum sensitivity and minimal power dissipation, along with advanced semiconductor IC’s for signal processing and power conversion. Solar recharging enables the sensor to operate for extended time, on a single battery that should last for years without replacement. A proprietary software protocol, developed for communication integrity, is a critical part of the overall system and supports other sensor types and control elements with low data rates for a wireless Vehicle Area Network. The system, successfully installed on several military training platforms, proves to be a viable product for military training and simulation systems for the 21st century.