Jones, Charles H.; Gardner, Lee S.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      “The radio frequency spectrum is a limited natural resource; therefore, efficient use of available spectrum is mandatory.” IRIG Standard 106-96 [4] As the availability of the frequency spectrum decreases and demands for bandwidth from users increases, the telemetry community will have to find ways to use spectrum efficiently. This paper is an overview of the major areas of research that promise potential increases in the efficient use of the telemetry spectrum. The discussion is summarized in a matrix that compares potential gains with overall costs for each research area using relative values of high, medium, and low.

      Wei, Zeng; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1998-10)
      In this paper, it is introduced that a C-Band mobile telemetry system designed for the satellite telemetry task. It can provide a wide range of bit rate and different code type and frame format which is completely set up by user in advance, to meet the requirements needs in different satellites. The PCM-PSK-PM signal and the PPM-MFSK-PM signal can be received and demodulated at the same time. Single channel monopulse technique is employed for automatic tracking. Angle calibration and angle tracking are performed in this system. Real-time data processing, displaying, testing of bit error rate and post-flight analyses is performed by PC type computer. All key components of the system may be programmed.
    • Calendars and Current Calendar Issues: Year 2000 and GPS 1999 Week Number Roll Over

      Claflin, Ray, III; Claflin Associates (International Foundation for Telemetering, 1998-10)
      This paper will present a selected overview of calendars and calendar development from antiquity to the current Gregorian calendar. The current hot topics of the GPS 1999 Rollover and the Year 2000 Millennium Rollover will be explained.

      Fantini, Jay A.; Woodside Summit Group Incorporated (International Foundation for Telemetering, 1998-10)
      Dryden real-time flight simulators encompass the simulation of pulse code modulation (PCM) telemetry signals. This paper presents a new method whereby the calibration polynomial (from first to sixth order), representing the conversion from counts to engineering units (EU), is numerically inverted in real time. The result is less than onecount error for valid EU inputs. The Newton-Raphson method is used to numerically invert the polynomial. A reverse linear interpolation between the EU limits is used to obtain an initial value for the desired telemetry count. The method presented here is not new. What is new is how classical numerical techniques are optimized to take advantage of modern computer power to perform the desired calculations in real time. This technique makes the method simple to understand and implement. There are no interpolation tables to store in memory as in traditional methods. The NASA F-15 simulation converts and transmits over 1000 parameters at 80 times/sec. This paper presents algorithm development, FORTRAN code, and performance results.

      Crockett, Donald E.; Arnold, David V.; Jensen, Michael A.; Brigham Young University (International Foundation for Telemetering, 1998-10)
      To help students learn the principles of microwave engineering and electromagnetic theory, labs were developed in which the students built a rail-synthetic aperture radar(SAR) and a Doppler radar. These labs gave the students practical experience in the paper design, simulation, construction, testing, and debugging of RF circuits. This paper includes a description of the design, physical construction, the basic operation, and the results from these projects.

      O’Cull, Douglas C.; Microdyne Communications Technologies, Inc. (International Foundation for Telemetering, 1998-10)
      This paper will discuss the design and performance of a multi-mode receiver. The receiver is designed to operate in standard VME and PC environments and will support data rates up to 20 Mbps. The paper will discuss new digital demodulation techniques that support PCM-FM, PCM-PM, FM, PM, BPSK, QPSK and O-QPSK modulation. This new demodulator also includes a built in bit sync with soft decision outputs. This paper will provide an overview on digital filtering used in the second IF filter which provides dynamic changing of the IF bandwidth.

      O’Cull, Douglas C.; Microdyne Corporation (International Foundation for Telemetering, 1998-10)
      Today’s increased satellite usage has placed an increased demand for high performance low cost satellite TT&C receiver systems. Many of the receiver systems being installed are using VME or PC platforms to provide streamlined computer based installations. This paper will describe the design and performance of a VME/PC based satellite TT&C receiver. The paper will provide a block level description of a 70 MHz receiver which uses a PM/FM digital demodulator. The paper will also provide performance data for a PM/BPSK sub-carrier satellite application.

      Weis, R. Stephen; Bachim, Brent L.; Texas Christian University (International Foundation for Telemetering, 1998-10)
      The design and testing of an optical fiber telemetry link for use in rugged environments is described. Several potential applications for this cost effective telemetry link built from readily available components are given. The results of testing the simple telemetry link for vibrations up to 20g and temperatures up to 150° C are reported.

      Lennox, William M.; Microdyne Corporation (International Foundation for Telemetering, 1998-10)
      The new NASA LEO-T (Low-Earth Orbite Ground Systems) satellite systems requires a wide range of data rates including extra wide-band requirements with near theoretical performance standards. This paper describes new design implementations incorporated into a COTS (Commercial Off-The-Shelf) Telemetry Receiver and Combiner System redesigned to meet the new wide band data requirements for NASA’s LEO-T satellite down link telemetry data requirement. The paper will also provide performance data showing system performance for the high data rates.

      DiLemmo, Marc C.; Aydin Telemetry (International Foundation for Telemetering, 1998-10)
      This paper illustrates a device driver implementation used to support a PC compatible telemetry device. Device requirements included operation on Windows NT 4.0, Windows 95, Windows NT 5.0 and Windows 98 platforms. A single device driver was not possible due to the differences between driver requirements on the various operating systems. The Windows Driver Model (WDM) was considered for NT 5.0 and Win98, however, NT 4.0 and Win95 does not support the WDM. To minimize software development and support efforts, it was clear that an architecture compatible to both WDM, NT 4.0 and Windows 95 needed to be developed. The resulting layered device driver architecture provides a common upper interface and uses a register based model to describe the hardware at the lower interface. The common upper interface is compatible with all of the target operating systems and presents a consistent Applications Programming Interface (API) for the telemetry application developer. The lower interface is specific for each platform but contains minimal device specific functionality. A simple register I/O driver is easily implemented using all of the target operating systems. The layered architecture and register based interface to the hardware results in a multiple operating system code set which differs only at the lowest layer.

      De Leon, Phillip L.; Scaife, Bradley J.; New Mexico State University (International Foundation for Telemetering, 1998-10)
      In any satellite communication, the Doppler shift associated with the satellite’s position and velocity must be calculated in order to determine the carrier frequency. If the satellite state vector is unknown then some estimate must be formed of the Doppler-shifted carrier frequency. One elementary technique is to examine the signal spectrum and base the estimate on the dominant spectral component. If, however, the carrier is spread (as in most satellite communications) this technique may fail unless the chip rate-to-data rate ratio (processing gain) associated with the carrier is small. In this case, there may be enough spectral energy to allow peak detection against a noise background. In this paper, we present a method to estimate the frequency (without knowledge of the Doppler shift) of a spread-spectrum carrier assuming a small processing gain and binary-phase shift keying (BPSK) modulation. Our method relies on a simple, averaged discrete Fourier transform along with peak detection. We provide simulation results indicating the accuracy of this method. In addition, we will describe an all-digital hardware design based around a Motorola DSP56303 and high-speed A/D which implements this technique in real-time. The hardware design is to be used in NMSU’s implementation of NASA’s demand assignment, multiple access (DAMA) service.

      Jones, Charles H.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Data cycle maps (DCM) describe the cyclic mapping of telemetered data. The efficiency of a DCM thus directly effects the efficiency of the use of the telemetry spectrum. The availability of this spectrum is decreasing while the demand is increasing. Certainly one of the first things to be done in trying to alleviate this bandwidth crunch is to make sure that all bits in a telemetry stream are useful and required. This paper provides results of a study on what types of bits there are in a DCM and how the bits were allocated in DCMs actually used at Edwards AFB, California.

      Herold, F. W.; Kaiser, J. A.; Fredrick Herold & Associates, Inc. (International Foundation for Telemetering, 1998-10)
      Conventional phased arrays nominally sum the signals received by the elements prior to detection. By multiplying rather than summing signals received from pairs of elements, i.e., interferometer pairs, a set of Spatial Frequencies (SFs) is obtained. Obtaining the SFs requires employment of a multiple local oscillator technique. When summed, these spatial frequencies produce a single lobed (voltage) radiation pattern which, when passed through a biased detector, removes all sidelobes from the response at a small loss of desired signal power.

      Eslinger, Brian; Garza, Reynaldo; TYBRIN Corp.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Communications support for the X-33 requires addressing several unique challenges to meet program and range safety requirements. As an avenue to minimize costs, the program has reduced requirements to the communications system, which lowered the cost of networking the extended range. Cost trade-offs showed that by lowering the telemetry data rate from 2 Megabits per second to 1.440 Megabits per second that significant cost avoidance could be realized. Also, by adopting standard telecommunications data rate for the uplink data stream, an efficient and integrated solution for the extended range communications could be supported. Meeting the program requirements as well as range safety requirements for this effort are critical to the success of the program. This paper describes some of the important requirements driving the design of the extended range communications support and the design of the system to meet those requirements.

      DeBenedetto, Louis J.; Myriad Logic, Inc. (International Foundation for Telemetering, 1998-10)
      Since becoming an ANSI standard in 1994, Fibre Channel has matured into a high-speed reliable data communication solution. Fibre Channel uses point-to-point, arbitrated loop, or switched topologies, to provide a wide range of options for data storage and highspeed data transfer applications. Unlike Gigabit Ethernet, Fibre Channel supports protocols such as HIPPI-FP, SCSI and IPI, allowing for greater flexibility when designing systems. However, the wide range of options supported in the Fibre Channel standard can be the source of misunderstanding and incompatibility. This paper intends to clear up some of the misconceptions about Fibre Channel by presenting the current standard and discussing how Fibre Channel can be used in data acquisition systems. Since these systems often require extremely high throughput for routing data, as well as high speed data storage to long term media, solutions are not often cut and dry. This paper will give examples of how using different layers of the Fibre Channel protocol will meet the needs of today’s data acquisition requirements. It provides a brief overview of Fibre Channel technology and identifies the different types of Fibre Channel products available. It provides examples of how commercial-off-the-shelf (COTS) products can be used to build data acquisition and storage systems requiring throughputs of up to 90 Mbytes per second on a single fiber. Additionally, it shows how multiple fibers can be used to achieve much higher data rates.
    • FQPSK Doubles Spectral Efficiency of Telemetry: Advances and Initial Air to Ground Flight Tests

      Feher, Kamilo; Digcom, Inc.; University of California (International Foundation for Telemetering, 1998-10)
      FQPSK is the abbreviation for Feher Quadrature Phase Shift Keying (FQPSK) patented systems [1]. Digcom, Inc. licensed FQPSK products demonstrated significant spectral saving and RF power efficient robust BER performance advantages. These bit rate agile modems and Non Linearly Amplified (NLA) transceivers, DSP and hardware implementations, and in some instances “software-radios” (20kb/s to more than 100Mb/s) and RF frequency agile (from 150MHz to more than 40GHz) developments and systems have recently been demonstrated and deployed. The spectral efficiency, i.e., data throughput capability of the 1st generation of FQPSK, as demonstrated in initial Advanced Range Telemetry (ARTM) flight tests, approximately doubles while 2nd generation “FQPSK-2” systems have the potential to quadruple the spectral efficiency of operational PCM/FM telemetry systems and be backward compatible with the 1st generation of FQPSK technologies. It is also demonstrated that the spectral efficiency advantage of FQPSK over that of NLA power efficient GMSK, OQPSK and QPSK modulated transceivers is in the 50% to 300% range and that the potential spectral efficiency advantage of FQPSK-2 over GMSK [1] is in the 200% to 500% range. Based on extensive multi-year studies of alternative solutions for spectral and RF power efficient, robust BER performance systems, several commercial US and international organizations, AIAA, CCSDS, NASA, ESA, CCSDS and various programs of the US Department of Defense (DoD) concluded that FQPSK offers the most spectrally efficient high performance-high speed proven technology solutions and recommended FQPSK standardization for several data links. Initial DoD-ARTM Program Office Air-to-Ground L-band and S-band jet airborne telemetry Test and Evaluation (T&E) data, obtained during the summer of 1998 are briefly highlighted. These include simultaneosly tested FQPSK and PCM/FM. In these tests the following ARTM objectives have been demonstrated: (a) FQPSK approximately doubles the spectral efficiency of currently operational PCM/FM; (b) The Data Link Performance of these two systems is comparable. The American Institute of Aeronautics and Astronautics (AIAA) draft modulation standard recommended to the DoD, NASA and CCSDS, was approved by the AIAA [23]. The AIAA standard recommends “that FQPSK modulation be immediately adopted as the interim increment–1 standard.”
    • FQPSK-L: An Improved Constant Envelope Modulation Scheme for QPSK

      Lee, Tong-Fu; Wang, Shih-Ho; Liu, Chia-Liang; Bao, Liu; University of California Davis; Industrial Technology Research Institute; Tianjin University (International Foundation for Telemetering, 1998-10)
      A new constant envelope modulation scheme and architecture for QPSK by cubic spline interpolation methods which increase spectral efficiency and power efficiency, named FQPSK-L, is presented. This modulation technique is an extension of the Feher Quadrature Shift Keying (FQPSK) patented technologies, see Ref [1]. Being a constant envelope modulation, FQPSK-L can operate with class C power amplifier without spectrum regrowth. We achieve a more compact spectrum with comparable bit error rate performance. For example, FQPSK-L is about 20% more spectral efficient than GMSK BTb=0.3 from 40 to 70 dB attenuation point. Moreover, FQPSK-L intrinsically has spikes at fc ± 0.5fb, fc ± 1.0fb, fc ± 1.5fb, ... which are useful for carrier recovery, symbol time recovery and fading compensation. In Rayleigh fading channel, FQPSK-L outperform GMSK BTb=0.3 by 0.8 dB. FQPSK-L is an excellent scheme for wireless and satellite communications which require high spectral and power efficiency.
    • FQPSK-O: An Improved Performance Constant Envelope Modulation Scheme for OQPSK

      Lee, Tong-Fu; Wang, Shih-Ho; Liu, Chia-Liang; University of California; Industrial Technology Research Institute (International Foundation for Telemetering, 1998-10)
      A new constant envelope modulation scheme for OQPSK, called FQPSK-O, is presented. This modulation technique is an extension of the Feher Quadrature Shift Keying (FQPSK) patented technologies, see Ref[l]. This scheme uses cubic spline interpolation to generate very smooth baseband waveforms in order to increase the spectral and power efficiency. Being a constant envelope modulation, FQPSK-O can operate with class C power amplifier without spectrum regrowth. We achieve a more compact spectrum with comparable bit error rate performance. For example, the spectrum of FQPSK-O is 25% narrower than that of GMSK with BT(b)=0.3 and FQPSK-1 with hardlimiter [2] at -40 dB attenuation point. For coherent demodulation under AWGN channel, FQPSK-O has almost the same BER performance as FQPSK-1 with hardlimiter. Both of them are better than GMSK with BT(b)=0.3 for BER < 10^-4. In Rayleigh fading channel, FQPSK-O outperforms GMSK with BT(b)=0.3 by 2 dB. FQPSK-O is an excellent scheme for wireless and satellite communications which require high spectral and power efficiency.

      Wexler, Marty; L-3 Communications (International Foundation for Telemetering, 1998-10)
      The necessity to acquire and analyze data dates back to the beginning of science itself. Long ago, a scientist may have run experiments and noted the results on a piece of paper. These notes became the data. The method was crude, but effective. As experiments got more complex, the need for better methodologies arose. Scientists began using computers to gather, analyze, and store the data. This method worked well for most types of data acquisition. As the amount of data being collected increased, larger computers, faster processors, and faster storage devices were used in order to keep up with the demand. This method was more refined, but still did not meet the needs of the scientific community. Requirements began to change in the data acquisition arena. More people wanted access to the data in real time. Companies producing large data acquisition systems began to move toward a network-based solution. This architecture featured a specialized computer called the server, which contained all of the data acquisition hardware. The server handled requests from multiple clients and handled the data flow to the network, data displays, and the archive medium. While this solution worked well to satisfy most requirements, it fell short in meeting others. The ability to have multiple computers working together across a local or wide area network (LAN or WAN) was not addressed. In addition, this architecture inherently had a single point of failure. If the server machine went down, all data from all sources was lost. Today, we see that the requirements for data acquisition systems include features only dreamed of five years ago. These new systems are linked around the world by wide area networks. They may include code to command satellites or handle 250 Mbps download rates. They must produce data for dozens of users at once, be customizable by the end user, and they must run on personal computers (PCs)! Systems like these cannot work using the traditional client/server model of the past. The data acquisition industry demands systems with far more features than were traditionally available. These systems must provide more reliability and interoperability, and be available at a fraction of the cost. To this end, we must use commercial-off-the-shelf (COTS) computers that operate faster than the mainframe computers of only a decade ago. These computers must run software that is smart, reliable, scalable, and easy to use. All of these requirements can be met by a network of PCs running the Windows NT operating system.
    • High Explosive Radio Telemetry System

      Crawford, Ted; Bracht, Roger; Johnson, Richard; Mclaughlin, Barry; Los Alamos National Laboratories; AlliedSignal Federal Manufacturing & Technologies (International Foundation for Telemetering, 1998-10)
      This paper overviews the High Explosive Radio Telemetry (HERT) system, under co-development by Los Alamos National Laboratories and AlliedSignal Federal Manufacturing & Technologies. This telemetry system is designed to measure the initial performance of an explosive package under flight environment conditions, transmitting data from up to 64 sensors. It features high speed, accurate time resolution (10 ns) and has the ability to complete transmission of data before the system is destroyed by the explosion. In order to affect the resources and performance of a flight delivery vehicle as little as possible, the system is designed such that physical size, power requirements, and antenna demands are as small as possible.