Perrins, Erik; Chandran, Prashanth; University of Kansas (International Foundation for Telemetering, 2007-10)
      Shaped offset quadrature phase shift keying (SOQPSK) is a highly bandwidth efficient modulation technique used widely in military and aeronautical telemetry standards. It can be classified as a form of continuous phase modulation (CPM), but its major distinction from other CPM schemes is that it has a constrained (correlated) ternary data alphabet. CPM-based detection models for SOQPSK have been developed only recently. One roadblock standing in the way of these detectors being adopted is that existing symbol timing recovery techniques for CPM are not always applicable since the data symbols are correlated. We investigate the performance of one CPM-based timing error detector (TED) that can be used with SOQPSK, and apply it to the versions of SOQPSK used in military (MIL-STD SOQPSK) and telemetry group (SOQPSK-TG) standards. We derive the theoretical performance limits on the accuracy of timing recovery for SOQPSK, as given by the modified Cramer-Rao bound (MCRB), and show that the proposed TED performs close to these bounds in computer simulations and is free of false-lock points. We also show that the proposed scheme outperforms a non-data aided TED that was recently developed for SOQPSK. These results show that the proposed scheme has great promise in a wide range of applications due to its low complexity, strong performance, and lack of false-lock points.

      Kilpatrick, Stephen; Rasche, Galen; Cunningham, Chris; Moodie, Myron; Abbott, Ben; Southwest Research Institute (International Foundation for Telemetering, 2007-10)
      Ubiquitous internet protocol (IP) hardware has reached performance and capability levels that allow its use in data collection and real-time processing applications. Recent development experience with IP-based airborne data acquisition systems has shown that the open, pre-existing IP tools, standards, and capabilities support this form of distribution and sharing of data quite nicely, especially when combined with IP multicast. Unfortunately, the packet based nature of our approach also posed some problems that required special handling to achieve performance requirements. We have developed methods and algorithms for the filtering, selecting, and retiming problems associated with packet-based systems and present our approach in this paper.

      Bester, Manfred; Stroozas, Brett; Bester Tracking Systems, Inc.; Stroozas Flight Ops (International Foundation for Telemetering, 2007-10)
      In a modern ground control network for space communications, secure peer-to-peer TCP/IP network socket connections are typically used to transfer real-time telemetry and command frames between satellite operations centers and remote ground stations. Reliable and timely reconfiguration of data paths for upcoming pass supports becomes rather complex when many spacecraft and ground stations are involved. This paper describes a routing software application that was developed to facilitate switching of telemetry and command data paths between multiple ground stations and spacecraft command and control systems, and to forward telemetry streams to multiple client applications in parallel. Fully automated configuration and monitoring of the data flows is accomplished via a remote control interface that is tied into a pass scheduling system. The software is part of the SatTrack Suite and currently supports multi-mission flight operations, including those of the recently launched THEMIS constellation mission at Space Sciences Laboratory, University of California at Berkeley.

      K/Bidy, Gilles; L-3 Communications (International Foundation for Telemetering, 2007-10)
      As part of the technology upgrades driven by the iNet initiative, there is a need to establish a meta-data standard to describe configuration information for the system under test. The technology identified for such a standard is XML and XSD schemas. This paper presents findings from various experiments to import and export existing telemetry configuration information to XML based on the new Meta-data model. In addition, this paper will discuss the possible conversions to and from the existing IRIG TMATS standard.

      Guadiana, Juan; Benitez, Jesus; Tiqui, Dwight; White Sands Missile Range (International Foundation for Telemetering, 2007-10)
      Migrating analog architectures and equipments to network architectures is underway all across the globe. There is no doubt, a modern instrument must fit the network environment or simply will not be procured. Yet, funding constraints temper wholesale changes to net-centric technologies. The last analog stronghold in our data center is the oscillograph. Over 50 Gould TA 6000 Oscillographs reside at White Sands Missile Range. These are digital implementations of analog recorders, hence require analog signaling. Digital telemetry data (most common format) must be converted to analog to drive an oscillograph that converts analog back to digital to plot the data. The oscillograph’s interface board may be “hacked” by removing the Analog to Digital Converter (ADC) gaining direct access to the digital signal path. This idea was worth attempting as the prospect of replacing that many recorders with the newer network driven oscillographs is costly hence remote. This paper’s topic is the conversion of the hardware and a discussion on software issues. Though not pretty, it does preserve the large recorder investment for the time being. Issues with analog signaling, such as noise, drift and ground loops are gone. A commercial ethernet to digital adapter drives the new digital interface and transforms the recorder into an net-centric instrument.
    • Iterative Decoding and Sparse Channel Estimation for an Underwater Acoustic Telemetry Modem

      Iltis, Ronald A.; University of California (International Foundation for Telemetering, 2007-10)
      An acoustic modem employing direct-sequence spread-spectrum (DSSS) signaling is considered with LDPC coding. The underwater acoustic channel is tracked using a Kalman filter which requires accurate data decisions. To improve KF performance and reduce the overall error rate, joint iterative LDPC decoding and channel estimation is proposed based on a factor graph and sum-product algorithm approximation. In this scheme, the decoder posterior log likelihood ratios (LLRs) provide data decisions for the KF. Decoder extrinsic LLRs are similarly incorporated into the detector LLRs to yield improved priors for decoding. Error rate simulations of the overall modem are provided for a shallow-water channel model with Ricean/Rayleigh fading.
    • The Sum-Rate Capacity of a Cognitive Multiple Access Sensor Network

      Panagos, Adam; Kosbar, Kurt; Dynetic, Inc.; University of Missouri (International Foundation for Telemetering, 2007-10)
      This paper investigates the sum-rate capacity of a cognitive multiple access (MAC) sensor network. The multiple access network consists of K sensors communicating to a common base station. Outside of the network exists another user of the radio spectrum. Each sensor of the MAC network is aware (i.e. cognitive) of this user, denoted the primary user, and transmits in a manner to avoid any interference to this user. No interference transmission is achieved using the dirty-paper coding technique. The sum-rate capacity is the theoretical maximum of the sum of the simultaneously achievable rates of each sensor within the network. Using a recently derived iterative algorithm, we quantify the sum-rate capacity of this network and investigate its behavior as a function of the number of sensors, cognitive signal-to-noise ratio (CSNR) and primary SNR (PSNR) in a Rayleigh fading environment. We also derive bounds and scaling results for the ergodic sum-rate capacity.

      Eslinger, Brian; Kovach, Bob; TYBRIN Corporation; Superior Access Solutions (SAS) (International Foundation for Telemetering, 2007-10)
      The RCC TTG initiated task TT-49 to generate a standard for the transport of serial streaming telemetry (TM) over the Internet Protocol (IP). An ad hoc committee was activated comprised of Range and vendor participation to develop this standard. This paper will address the progress of the standard, the use of commercial standards, and the benefits to the ranges. The early meetings focused on developing the packet structure; the preliminary results will be presented along with the latest status on the RCC approval cycle.

      Perrins, Erik; Syed, Afzal; University of Kansas (International Foundation for Telemetering, 2007-10)
      SOQPSK and GMSK are highly bandwidth efficient continuous phase modulation (CPM) schemes with several desirable qualities. In both cases, coherent detectors are available with good performance in AWGN. In this paper, we develop reduced complexity noncoherent detectors for SOQPSK and GMSK; and discuss a phase noise model. This is followed by a performance comparison of both the noncoherent detectors in channels with phase noise.
    • International Telemetering Conference Proceedings, Volume 43 (2007)

      Unknown author (International Foundation for Telemetering, 2007-10)

      Roach, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2007-10)
      The development of network-based data acquisition systems has resulted in a new architecture for supporting flight instrumentation that has the potential to revolutionize the way we test our aircraft. However, the inherent capability and flexibility in a networked test architecture can only be realized by the flight engineer if a sufficiently powerful toolset is available that can configure and manage the system. This paper introduces the concept of an instrumentation configuration and management system (ICMS) that acts as the central resource for configuring, controlling, and monitoring the instrumentation network. Typically, the ICMS supports a graphical user interface into the workings of the instrumentation network, providing the user with a friendly and efficient way to verify the operation of the system. Statistics being gathered at different peripherals within the network would be collected by this tool and formatted for interpretation by the user. Any error conditions or out-of-bounds situations would be detected by the ICMS and signaled to the user. Changes made to the operation of any of the peripherals in the network (if permitted) would be managed by the ICMS to ensure consistency of the system. Furthermore, the ICMS could guarantee that the appropriate procedures were being followed and that the operator had the required privileges needed to make any changes. This paper describes the high-level design of a modular and multi-platform ICMS and its use within the measurement-centric aircraft instrumentation network architecture under development by the Network Products Division at Teletronics.

      Brown, T. Gordon; Vong, Timothy; Topper, Ben; U.S. Army Research Laboratory; Data Matrix Solutions, Inc (International Foundation for Telemetering, 2007-10)
      The U.S. Army Research Laboratory (ARL) was requested by the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) to perform a free-flight experiment with a telemetry (TM) instrumented sub-scaled Apollo shaped reentry vehicle in order to determine its aerodynamic coefficients. ARL has developed a unique flight diagnostic capability for reconstructing flight trajectory and determining aerodynamic coefficients of projectiles by using sensor data telemetered from free flight experiments. A custom launch package was designed for this experiment that included the Apollo shaped projectile, which housed a modular telemetry unit, and a rapid prototyped sabot. The experiment was able to produce estimates for aerodynamic coefficients that were considered accurate and this technique is appealing to NASA for the development of their spacecraft in the future.

      Fewer, Colm; Wilmot, Sinbad; ACRA CONTROL INC (International Foundation for Telemetering, 2007-10)
      Since the 1970s PCM/FM has been the dominant modulation scheme used for RF telemetry. However more stringent spectrum availability as well as increasing data rates means that more advanced transmission methods are required to keep pace with industry demands. ARTM Tier-I and Tier-II are examples of how the PCM/FM link can be enhanced. However these techniques require a significant increase in the complexity of the receiver/detector for optimal recovery. This paper focuses on a quantitative approach to improving the rate and quality of data using existing PCM/FM links. In particular ACRA CONTROL and BAE SYSTEMS set themselves the goal of revisiting the pre-modulation filter, diversity combiner and bit-sync. By implementing programmable adaptive hardware, it was possible to explore the various tradeoffs offered by modifying pulse shapes and spectral occupancy, inclusion of forward error correction and smart source selection. This papers looks at the improvements achieved at each phase of the evaluation.
    • Network Design Considerations in Telemetry Systems

      Grebe, Andy; Klein, Wayne; Apogee Labs, Inc. (International Foundation for Telemetering, 2007-10)
      In today’s world, computer networking has become common place both in industry as well as home, however all networks are not the same! The Telemetry world, like with many industries, has critical design considerations that need to be evaluated when you begin a new system or just adding on to a current infrastructure. This paper is intended to outline needed considerations when planning or implementing a network design in Telemetry Systems. These applications can range from sensor data transport through High Definition/High Speed Video applications.
    • Evolving Range and DISA Networks Using Pseudo Wire

      Merritt, Joseph; Avtec Systems, Inc. (International Foundation for Telemetering, 2007-10)
      The Eastern and Western Ranges along with DISA share a similar vision around Net-Centricity such that "Anyone, anywhere can get to any data source and exploit the information they are authorized to access." Their legacy infrastructure is built around TDM and ATM transport networks, which are link based and connection oriented. To achieve the vision the infrastructure must evolve towards a packet switched network (PSN) that is meshed based. Consequently, a means to interwork non-IP enabled services is required. Pseudo Wire protocol encapsulation provides the means for extending telemetry, data, voice, and video services in native formats over Ethernet, IP, and MPLS networks in a reliable way that delivers greater operational efficiency and a smooth migration to a single converged network.

      Yudong, He; Xianghua, Yang; Jie, Zhou; Banghua, Zhou; Beibei, Shao; Tsinghua University; China Academy of Engineering Physics (International Foundation for Telemetering, 2007-10)
      Robust adaptive beamforming using worst-case performance optimization is developed in recent years. It had good performance against array response errors, but it cannot reject strong interferences. In this paper, we propose a scheme for robust adaptive beamforming with broad nulls to reject strong interferences. We add a quadratic constraint to suppress the power of the array response over a spatial region of the interferences. The optimal weighting vector is then obtained by minimizing the power of the array output subject to quadratic constrains on the desired signal and interferences, respectively. We derive the formulations for the optimization problem and solve it efficiently using Newton recursive algorithm. Numerical examples are presented to compare the performances of the robust adaptive beamforming with no null constrains, sharp nulls and broad nulls. The results show its powerful ability to reject strong interferences.

      Dongkai, Yang; Li, Du; Qishan, Zhang; Beihang University (International Foundation for Telemetering, 2007-10)
      This paper focuses on the transceiver design using BOC signal in the telemetry field, including the transmitter and receiver. The transmitter is similar as that using BPSK except from the sub-carrier modulation. But the receiver design is totally different because the BOC signal has different performance. The acquisition methods of BOC signal have been discussed such as the single-side BPSK-like, double-sides BPSK-like and hybrid processing methods, which can restrain side-peak and eliminate ambiguities. The three acquisition process principles and their performances include arithmetic complexity are described, compared and simulated using MATLAB.

      Mather, Jonathan; Shaw, Nancy; L-3 Communications Telemetry-West; Lockheed Martin Corporation (International Foundation for Telemetering, 2007-10)
      This paper presents a case study of the Western Range Centralized Telemetry Processing Subsystem (WR CTPS). This system was developed by Lockheed Martin Integrated Systems and Global Services and L-3 Communications Telemetry-West as part of the Range Standardization and Automation (RSA) IIA program. Requirements included real-time simultaneous acquisition of 16 PCM streams at rates of up to 30M bits per second; real-time processing; and data display on workstations connected over a gigabit Ethernet network. This system is designed for range safety and needs to be fault-tolerant while maintaining 100 percent data availability in the event of a single failure during an operation. The development of such a system demanded a rigorous Systems Engineering approach to ensure the successful upgrade and deployment onto the range infrastructure. This case study provides an overview of the system technical requirements and its architecture. The summary presents challenges encountered during the development and lessons learned while meeting them.

      Grace, Thomas; Hodack, Dave; Naval Air Systems Command (International Foundation for Telemetering, 2007-10)
      iNET is a project tasked to foster advances in networking and telemetry technology to meet emerging needs. This paper describes one objective of the project, which is standardization and interoperability. It begins to explore issues for achieving a level of interoperability among differing vendor’s hardware such as data acquisition units, data recorders, video systems, transceivers, and network encryption. Specifically, this paper addresses the expansion of the current demonstration system with the addition of multiple vendor data acquisition units. It will also attempt to address the level of standardization necessary for achieving interoperability while still enabling vendors to add their value added contributions into their products.

      Hudgins, Gene; TENA Software Development Activity (International Foundation for Telemetering, 2007-10)
      The Joint Mission Environment Test Capability (JMETC) is a distributed live, virtual, and constructive (LVC) testing capability developed to support the acquisition community and to demonstrate Net-Ready Key Performance Parameters (KPP) requirements in a customer-specific Joint Mission Environment (JME). JMETC provides connectivity to the Services’ distributed test capabilities and simulations, as well as industry test resources. JMETC uses the Test and Training Enabling Architecture, TENA, which is well-designed for supporting JMETC events. TENA provides the architecture and software capabilities necessary to enable interoperability among range instrumentation systems, facilities, and simulations. TENA, used in major field exercises and numerous distributed test events, provides JMETC with a technology already being deployed in DoD.