Lawson, Shawn; Brentzel, Kelvin; Harris, Carol; Coronado, Patrick; Pasciuto, Michael; Greenfield, Paul; Zajkowski, Thomas; Global Science and Technology; National Aeronautical Space Administration; United States Forest Service (International Foundation for Telemetering, 2003-10)
      NASA Goddard Space Flight Center (GSFC) is developing the Remote Internet Protocol Communication (RIPCom) system, which is a wireless communication system that makes an aircraft look like a network node in the sky. RIPCom provides an Ethernet to Radio Frequency (RF) connection solution for real-time data transmission, and its design allows the end points of the communication system to become nodes on a network with assigned IP addresses. RIPCom’s design is especially suitable for Unmanned Aerial Vehicle (UAV) applications, and its versatility makes it valuable for many systems that require a high speed, digital wireless network.

      Carper, Richard D.; Space Data Systems (International Foundation for Telemetering, 2003-10)
      The CCSDS recently developed the CCSDS File Delivery Protocol which can operate in configurations from simple point-to-point space/ground systems to complex arrangements of orbiters, landers, relaying spacecraft, and multiple ground facilities. An international interoperability test program has been developed in support of the development and fielding of the protocol. The first phase was successfully completed in the Fall of 2002. The second phase is to be completed about the time of the presentation of this paper. First phase testing involved five independent implementations of the Core Procedures of the protocol. Since these Procedures are for point-to-point file transfers, only two protocol “entities” were involved in each executed test. The second phase tests other Procedures, which involve multi-hop transferring of files. This phase will involve two separate, independent implementations, with one implementation being hosted on multiple hardware/OS platforms. Each test will involve three or more entities.

      Ray, Tim; National Aeronautics and Space Administration; Goddard Space Flight Center (International Foundation for Telemetering, 2003-10)
      Reliable delivery of data products is often required across space links. For example, a NASA mission will require reliable delivery of images produced by an on-board detector. Many missions have their own (unique) way of accomplishing this, requiring custom software. Many missions also require manual operations (e.g. the telemetry receiver software keeps track of what data is missing, and a person manually inputs the appropriate commands to request retransmissions). The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) specifically for this situation. CFDP is an international standard communication protocol that provides reliable delivery of data products. It is designed for use across space links. It will work well if run over the widely used CCSDS Telemetry and Telecommand protocols. However, it can be run over any protocol, and will work well as long as the underlying protocol delivers a reasonable portion of the data. The CFDP receiver will autonomously determine what data is missing, and request retransmissions as needed. The CFDP sender will autonomously perform the requested transmissions. When the entire data product is delivered, the CFDP receiver will let the CFDP sender know that the transaction has completed successfully. The result is that custom software becomes standard, and manual operations become autonomous. This paper will consider various ways of achieving reliable file delivery, explain why CFDP is the optimal choice for use over space links, explain how the core protocol works, and give some guidance on how to best utilize CFDP within various mission scenarios. It will also touch on additional features of CFDP, as well as other uses for CFDP (e.g. the loading of on-board memory and tables).

      Burleigh, Scott; California Institute of Technology (International Foundation for Telemetering, 2003-10)
      Delay-tolerant networking (DTN) is a system for constructing automated data networks in which end-to-end communication is reliable despite low data rates, possible sustained interruptions in connectivity, and potentially high signal propagation latency. As such it promises to provide an inexpensive and robust medium for returning telemetry from research vehicles in environments that provide meager support for communications: deep space, the surface of Mars, the poles or the sub- Arctic steppes of Earth, and others. This paper presents an overview of DTN concepts, including “bundles” and the Bundling overlay protocol. One possible scenario for the application of DTN to a telemetry return problem is described, and there is a brief discussion of the current state of DTN technology development.

      Gudmundson, Stephan; NetAcquire Corporation (International Foundation for Telemetering, 2003-10)
      While the transition to IP internetworking in space-based applications has a tremendous upside, there are significant challenges of communications efficiency and compatibility to overcome. This paper describes a very high efficiency, low-risk, incremental architecture for migrating to IP internetworking based on the use of proxies. In addition to impressive gains in communications bandwidth, the architecture provides encapsulation of potentially volatile decisions such as particular vendors and network technologies. The specific benchmarking architecture is a NetAcquire Corporation COTS telemetry system that includes built-in TCP-Tranquility (also known as SCPS-TP) and Reed-Solomon Forward Error Correction capabilities as well as a specialized proxy-capable network stack. Depending on network conditions, we will show that the effective bandwidth for satellite transmissions can be increased as much as a factor of one hundred with no external changes to existing internetworking equipment.

      Horan, Stephen; Newtson, Kathy; New Mexico State University (International Foundation for Telemetering, 2003-10)
      Prototyping an Internet Protocol (IP) compliant architecture will demonstrate a realistic basis for satellite communication design. The prototype IP architecture should prove seamless and secure communications between the satellites and ground stations. Using commercial off the shelf (COTS) equipment, design and development of satellite communications becomes easier and less expensive than developing specialized equipment. IP space applications will improve communications while minimizing development costs.

      Sinclair, Robert; Beech, Russell; Jones, Kevin; Mundon, Scott; Jones, Charles H.; NVE Corporation; Edwards Air Force Base (International Foundation for Telemetering, 2003-10)
      When a sensor is replaced or added to a legacy data acquisition system, information for that sensor has to be incorporated by the software programmer into the main system software - a costly and timeconsuming process. The new ‘smart’ sensors that are being designed according to the new IEEE P1451.3 and .4 standards will have the necessary information contained in their Transducer Electronics Data Sheet (TEDS). A method has been developed to give the old sensors the intelligence to meet the requirements of these new IEEE standards without changes to the legacy hardware and a minor change to the system software.
    • IEEE P1451.4 Smart Transducers Template Description Language

      Jones, Charles H.; Edwards Air Force Base (International Foundation for Telemetering, 2003-10)
      The IEEE 1451.4 smart transducer interface standard [1] provides a mechanism for both analog and digital, or mixed mode, interfacing to sensors and actuators, which are collectively referred to as transducers. The analog mode allows normal interfacing to the transducer. The digital mode is intended to provide the ‘smarts’ by allowing the transducer to provide basic information to the application system. This information is referred to as the transducer electronic data sheet (TEDS) and contains information ranging from serial number to calibration data and electrical characteristics. A major driving force behind the development of the standard was to minimize the amount of memory required to store a TEDS; with a stated objective of only needing 256 bits, although more are allowed. This requires a method of mapping the bits in a precise fashion. This bit mapping is accomplished through templates which are text based files written in the Template Description Language (TDL). The TDL is a formal language similar to programming languages, but with considerably less looping and conditional control. This is because the entire purpose of the language is to map bits and not to implement general processing or mathematical capabilities. This paper outlines the functionality and syntax of the TDL.

      Mastrippolito, Luigi; Aberdeen Proving Ground (International Foundation for Telemetering, 2003-10)
      The US Army Aberdeen Test Center (ATC) is acquiring, transferring, and databasing data during all phases of automotive testing using networked data acquisition devices. The devices are small ruggedized computer-based systems programmed with specific data acquisition tasks and then networked together with other devices in order to share information within a test item or vehicle. One of the devices is also networked to a ground-station for monitor, control and data transfer of any of the devices on the net. Application of these devices has varied from single vehicle tests in a single geographical location up to a 100-vehicle nationwide test. Each device has a primary task such as acquiring data from vehicular data busses (MIL-STD-1553, SAE J1708 bus, SAE J1939 bus, RS-422 serial bus, etc.), GPS (time and position), analog sensors and video with audio. Each device has programmable options, maintained in a configuration file, that define the specific recording methods, real-time algorithms to be performed, data rates, and triggering parameters. The programmability of the system and bi-directional communications allow the configuration file to be modified remotely after the system is fielded. The primary data storage media of each device is onboard solid-state flash disk; therefore, a continuous communication link is not critical to data gathering. Data are gathered, quality checked and loaded into a database for analysis. The configuration file, as an integral part of the database, ensures configuration identity and management. A web based graphical user interface provides preprogrammed query options for viewing, summarizing, graphing, and consolidating data. The database can also be queried for more detailed analyses. The architecture for this network approach to field data acquisition was under the Aberdeen Test Center program Versatile Information System Integrated On-Line (VISION). This paper will describe how the merging of data acquisition systems to network communications and information management tools provides a powerful resource for system engineers, analysts, evaluators and acquisition personnel.

      Eccles, Lee H.; Boeing Commercial Airplanes (International Foundation for Telemetering, 2003-10)
      This paper describes the use of an IEEE p1451.3 Smart Sensor bus as part of a network centric data acquisition system. IEEE p1451.3 provides for synchronized data acquisition from a number of transducers on a bus. The standard provides for Transducer Electronic Data Sheets (TEDS) that the manufacturer can use to describe the function and capabilities of the sensor module. The standard also provides for TEDS where the user can store information relevant to a particular application. The information in these TEDS can be used to generate much of the information that is required to be able to process the data during or after a test. The use of this information to configure and operate a Network Based Data Acquisition is described.

      Brierley, Scott; The Boeing Company (International Foundation for Telemetering, 2003-10)
      Calculating the power spectral density (PSD) at the transducer or data acquisition system offers advantages in a network-based telemetry system. The PSD is provided in real time to the users. The conversion to PSD can either be lossless (allowing a complete reconstruction of the transducer signal) or lossy (providing data compression). Post-processing can convert the PSD back to time histories if desired. A complete reconstruction of the signal is possible, including knowledge of the signal level between the sample periods. Properly implemented, this method of data collection provides a sharp anti-aliasing filter with minimal added cost. Currently no standards exist for generating PSDs on the vehicle. New standards could help telemetry system designers understand the benefits and limitations calculating the power spectral density in a network-based telemetry system.

      Zhang, Zhengxuan; Zhang, Qishan; Beihang University (International Foundation for Telemetering, 2003-10)
      The IMS(In-vehicle Monitoring Subsystem) of VMS(Vehicle Monitoring System) is the multifunctional and complex integrate embedded system, which sends the data of various in-vehicle devices to MC(Monitoring Center) and accepts commands and schedules from there. Using GPRS platform in this system make it possible for real-time and effective data transmission. This paper proposes some new insights on IMS applied to public traffic, including its software and hardware composition, and its realization method.
    • A New TDRSS Compatible Transceiver for Long Duration High Altitude Scientific Balloon Missions

      Stilwell, Bryan D.; Siemon, Marty; New Mexico State University; General Dynamics Decision Systems (International Foundation for Telemetering, 2003-10)
      High altitude scientific balloons have been used for many years to provide scientists with access to space at a fraction of the cost of satellite based experiments. In recent years, these balloons have been successfully used for long duration missions of up to several weeks. Longer missions with durations of up to 100 days (Ultra-Long) are on the drawing board. An enabling technology for the growth of the scientific balloon missions is the use of the NASA Tracking and Data Relay Satellite System (TDRSS) for telemetering the health, status, position and payload science data to mission operations personnel. The TDRSS system provides global coverage by relaying the data through geostationary relay satellites to a single ground station in White Sands New Mexico. Data passes from the White Sands station to the user via commercial telecommunications services including the Internet. A forward command link can also be established to the balloon for real-time command and control. Early TDRSS communications equipment used by the National Scientific Balloon Facility was either unreliable or too expensive. The equipment must be able to endure the rigors of space flight including radiation exposure, high temperature extremes and the shock of landing and recovery. Since a payload may occasionally be lost, the cost of the TDRSS communications gear is a limiting factor in the number of missions that can be supported. Under sponsorship of the NSBF, General Dynamics Decision Systems has developed a new TDRSS compatible transceiver that reduces the size, weight and cost to approximately one half that of the prior generation of hardware. This paper describes the long and ultra-long balloon missions and the role that TDRSS communications plays in mission success. The new transceiver design is described, along with its interfaces, performance characteristics, qualification and production status. The transceiver can also be used in other space, avionics or terrestrial applications.

      Berdugo, Albert; Teletronics Technology Corporation (International Foundation for Telemetering, 2003-10)
      Gigabits and hundreds of megabit communication buses are starting to appear as the avionic buses of choice for new or upgraded airborne systems. This trend presents new challenges for instrumentation engineers in the areas of high speed data multiplexing, data recording, and data transmission of flight safety information. This paper describes the approach currently under development to acquire data from several types of high-speed avionic buses using distributed multiplexer and acquisition units. Additional input data may include PCM, wideband analog data, discrete, real-time video and others. The system is capable of multiplexing and recording all incoming data channels, while at the same time providing data selection down to the parameter level from input channels for transmission of flight safety information. Additionally, an extensive set of data capture trigger/filter/truncation mechanisms are supported.
    • Telemetry Data Encoder with an Embedded GPS Receiver

      Rivera, Alan; Herley Industries (International Foundation for Telemetering, 2003-10)
      This paper outlines the GPS data acquisition of two PCM encoders. The design of the first PCM Encoder uses an embedded GPS Receiver module, the Thales G12- HDMA receiver. The G12 Receiver has been integrated into the electronics of the PCM Encoder to provide a seamless tool for the Telemetry Engineer to acquire GPS position and time data with the sensor data acquired from the PCM Encoder. The second telemetry encoder discussed in this paper adds the GPS Interface Module for the Time Space Position Unit (TSPI) currently under development at Herley Industries. The TSPI Unit will also be integrated with the PCM Encoder tools to create a seamless user interface. The TSPI unit is available in both the “Low Dynamic (JTU-I)” and the “High Dynamic” (JTU-II).

      Chen, Dijin; McCorduck, James A.; Feher, Kamilo; University of California, Davis; MatrixSat, Inc.; DIGCOM, Inc. (International Foundation for Telemetering, 2003-10)
      For simpler implementations of ultra high bit rate systems, combined analog/digital techniques, described here in, provide implementations with the smallest number of component count utilizing minimal “real-estate” and smallest DC power. While digital implementations with tradition Read Only Memory (ROM) and Digital to Analog Converters (DAC’s) have been proven in several commercial, NASA -CCSDS recommended, and U.S. DoD-IRIG standardized Feher’s QPSK (FQPSK) [2,3] products, such implementations can be further simplified, and in particular for ultra high bit rate product applications. Several waveform generating techniques such as linear approximation, analog approximation and mixed analog and linear approximations are investigated using preliminary simulation results.

      Bottenfield, Joe; Moore, Vern; Herley Lancaster (International Foundation for Telemetering, 2003-10)
      This paper describes the implementation of a Feher-Patented Quadrature Phase Shift Keying (FQPSK) waveform variant that reduces overall design complexity, which in turn results in a telemetry transmitter that provides all the benefits of the existing FQPSK-B waveform, in a 3.0 x 2.0 x 1.0 volume. This variant is referred to the as the FQPSK-JR version. This waveform differs from the “near constant” envelop response of the qualified Herley airborne FQPSK-B telemetry transmitter in terms of the time domain wavelet transition functions and the amplitude scaling term associated with those functions. The end result is a “constant envelop” design, which employs simplified antialias filtering and more efficient digital design techniques.

      Law, Eugene; Naval Air System Command (International Foundation for Telemetering, 2003-10)
      This paper will present equations for calculating the minimum recommended frequency separation of two digital telemetry signals. The signals can be filtered continuous phase frequency shift keying (CPFSK), multi-h continuous phase modulation (CPM) [1], shaped offset quadrature phase shift keying-Telemetry Group (SOQPSK-TG, aka SOQPSK-A*) [2], or Feher’s patented quadrature phase shift keying FQPSK-B (or FQPSK-JR [3]). The equations are based on measured data in an adjacent channel interference (ACI) environment for filtered CPFSK (aka PCM/FM), multi-h CPM (or CPM for short), SOQPSK-TG, FQPSK-JR, and FQPSK-B. This paper is an extension of my 2001 and 2002 International Telemetering Conference papers on this topic [4, 5]. The quantity measured was bit error probability (BEP) versus frequency separation at a given signal energy per bit to noise power spectral density ratio (Eb/No). The interferers were CPFSK, CPM, SOQPSK-TG or FQPSK-B (-JR) signals. The results presented in this paper will be for a desired signal bit rate of 1 to 20 Mb/s, one interferer 20 dB larger than the desired signal (a few tests included two interferers), and various center frequency spacings, interfering signals, receivers, and demodulators. The overall ACI test effort has collected data sets at several bit rates and with one and two interferers. The results will be useful to system designers and range operators as they attempt to maximize the number of Mb/s that can be simultaneously transmitted with minimal interference in the telemetry bands.

      Wegener, John A.; Boeing Integrated Defense Systems (International Foundation for Telemetering, 2003-10)
      Due to increasing data rates required for Flight Test telemetry on upcoming programs, and because of increasing competition for spectrum space, Boeing Integrated Defense Systems (IDS) Flight Test in Saint Louis is considering use of the Feher-patented Quadrature Phase Shift Keying (FQPSK) modulation scheme. To determine potential operational issues associated with FQPSK, Boeing IDS Flight Test initiated a laboratory investigation of FQPSK using commercially available equipment including a transmitter from Herley and a demodulator from RF Networks. This paper describes the results of this laboratory investigation, including spectrum occupancy, bit-error rate performance, demodulator acquisition performance, demodulator bit-rate tracking, demodulator pattern sensitivity, and other operational characteristics.

      Rice, Michael; Perrins, Erik; Brigham Young University (International Foundation for Telemetering, 2003-10)
      A linear pulse-amplitude modulation (PAM) receiver for the ARTM Tier II multi-h waveform is presented. The receiver is optimal and can be implemented using maximum likelihood sequence estimation (MLSE). The linear signal model also allows many attractive complexity reductions. The performance of these reduced-complexity receivers is evaluated via computer simulation. One simplified receiver consists of three matched filters and a 32-state Viterbi trellis and is shown to perform with a 1:5 dB degradation relative to the optimal receiver.