• 0-Hz-IF FSK/AM Sub-Carrier Demodulator on a 6U-VME-Card

      Weitzman, Jonathan M.; GDP Space Systems (International Foundation for Telemetering, 1996-10)
      Aerospace Report No. TOR-0059(6110-01)-3, section 1.3.3 outlines the design and performance requirements of SGLS (Space Ground Link Subsystem) services. GDP Space Systems has developed a single card slot FSK (Frequency Shift Keying)/AM (Amplitude Modulation) demodulator. An application of this service is the US Air Force Satellite Command and Ranging System. The SGLS signal is tri-tone-FSK, amplitude modulated by a modified triangle wave at half the data rate. First generation FSK/AM demodulators had poor noise performance because the signal tones were filtered and processed at IF frequencies (65, 76 and 95 kHz). Second generation demodulators suffer from "threshold" due to non-linear devices in the signal path before the primary noise filtering. The GDP Space Systems demodulator uses a 0-Hz- IF topology and avoids both of these shortcomings. In this approach, the signal is first noncoherently down converted to baseband by linear devices, then it is filtered and processed. This paper will discuss the GDP 0-Hz-IF FSK/AM (SGLS) demodulator.

      McAVOY, N.; Goddard Space Flight Center (International Foundation for Telemetering, 1972-10)
      10-micrometer band communication systems using CO2 lasers for space to space links are discussed. Particular emphasis is on low earth orbiting earth observation satellites to geosynchronous satellites at high data rate. Four key technology areas are discussed: Wideband mixers for Doppler tracking; tunable laser local oscillators; high data rate modulators; laser transmitters.

      Goodwin, F. E.; Hughes Research Laboratories (International Foundation for Telemetering, 1972-10)
      This paper reports the development of an experimental type 10.6 μm laser communication system consisting of a transmitting terminal and a receiving terminal designed to operate one way over a nominal five mile terrestrial path. The system will provide a 5 Mbit/sec digital data channel utilizing intra-cavity optical frequency modulation, or frequency shift keying modulation format. It uses optical heterodyne detection with a mercury cadmium telluride detector operating at a temperature of 77°K and an i.f. frequency of 30 MHz. Since the system operates from fixed (non-mobile) terminals, acquisition and alignment procedures are simplified. Predicted performance in rain and fog is discussed and compared with a limited amount of actual data.
    • 10.6 Micron Laser Communication Experiment for ATS-F and ATS-G

      McElroy, J. H.; Richards, H. L.; McAvoy, N.; McGunigal, T. E.; Richards, W. E.; Yagelowich, H.; NASA Goddard Space Center (International Foundation for Telemetering, 1969-09)
      A laser communication system weighing 30 pounds and consuming 30 watts is to be flown on the ATS-F satellite for a space-to-ground experiment. An identical system proposed to be flown on ATS-G will complete an experimental intersatellite communication link. A 6-inch aperture optical antenna with a 92 dB antenna gain and a 500 mw carrier provide a minimum 23dB carrier-to-noise ratio for a 5 MHz bandwidth system. This experiment will permit analysis of laser Communication system parameters as a base line for future operational system designs, such as could be employed on a Data Relay Satellite. In addition to the NASA ground station, a station prepared by Bell Telephone Laboratories will perform atmospheric propagation experiments on the beam received from the satellite.

      Goodwin, Francis E.; Nussmeier, Thomas A.; Zavin, Jack E.; Hughes Research Laboratories; U. S. Army Electronics Command (International Foundation for Telemetering, 1973-10)
      This paper reports the development of an experimental type 10.6 μm laser communication system, consisting of a transmitter terminal and a receiver terminal, designed to operate one wav over a nominal five-mile path. The system provides a 5 MB/s digital data channel using a frequency shift keying format and optical heterodyne detection with a mercury cadmium telluride detector operating at a temperature of 77°K. The system is the first CO2 laser heterodyne communication system which is capable of hands-off, uninterrupted operation in a nonlaboratory environment. The achievement of single frequency operation of a laser transmitter and local oscillator in a field system is the result of more than seven years of research and development. Laser frequency purity, stability and control, all questions of primary concern previously, have been proven satisfactory with the development of this system. This paper reports the operation of the system during environmental tests, over a 4.1-mile test range, a 19.5-mile test range at the Hughes facility, and over a three mile test range at Ft. Monmouth, N.J. over a period of several months. During a period of 1320 hours of continuous operation, the system was inoperable for 65 hours due to weather conditions, demonstrating a reliability of 95%.
    • A 100 kHz System with Automatic Operation: The Omega IV Telemetry Processor

      Norton, Thomas R.; Norworth, Joseph I.; Stellarmetrics (International Foundation for Telemetering, 1968-10)
    • A 10W Low Cost OFDM Transceiver (LCOT)

      Sandhiya, Pallavi; Zaki, Nazrul; Satterfield, Rickey; Bundick, Steve; Thompson, Keith; Grant, Charles; NASA/GSFC Wallops Flight Facility (International Foundation for Telemetering, 2012-10)
      This paper details design, development and test of the Low Cost OFDM Transceiver (LCOT) LCT2-040-2200 module at S band. The goal of the project is to provide a low cost transmit and receive unit for demonstrating OFDM communication on a flight platform. The LCOT module is built to transmit and receive OFDM signals. It transmits OFDM signals at 10W power out through a custom built high power amplifier and conforms to the IEEE 802.11.g spectral emissions mask.
    • 117.6 Kilobit Telemetry from Mercury-A Major Deep Space Telecommunication Advance

      Clarke, Victor C.; California Institute of Technology (International Foundation for Telemetering, 1974-10)
      For nearly eight hours on March 29, 1974, Mariner 10 transmitted imaging telemetry in real time at 117.6 Kbps from Mercury. During this time, 562 very high quality frames were received, even though the bit error rate was only about 1 in 40. The transmission of 117.6 Kbps from Mercury is a magnificent telecommunications achievement, which permitted an order of magnitude increase in imaging science data return. The Mariner 10 imaging scientists' requirements, simply stated, were to obtain maximum area coverage at highest spatial resolution. More precisely, they desired photomosaics which were equivalent to the best earth-based pictures on the Moon, i.e., about 1 km resolution. The purpose of this paper is principally to relate the methods by which these "desirements" were translated into measurable telecommunication system requirements and some of the attendant tradeoffs. Additionally, same of the steps taken to achieve their goal are recited.
    • 117.6-Kilobit Telemetry from Mercury In-Flight System Analysis

      Evanchuk, V. L.; California Institute of Technology (International Foundation for Telemetering, 1974-10)
      This paper discusses very specifically the mode of the Mariner Venus/ Mercury 1973 (MVM'73) telecommunications system in the interplexed dual channel 117.6 kilobits per second (kbps) and 2.45 kbps telemetry. This mode, originally designed for only Venus encounter, was also used at Mercury despite significantly less performance margin. Detailed analysis and careful measurement of system performance before and during flight operations allowed critical operational decisions, which made maximum use of the system capabilities.
    • A 12-Year, Post-Wildfire Geomorphologic Evaluation of Ellison Creek, Central Arizona

      Medina, Alvin L.; Royalty, Rebecca K.; Rocky Mountain Research Station (Arizona-Nevada Academy of Science, 2002-04-06)
    • 120 Mb/s and 240 Mb/s Bit Synchronizer-Signal Conditioners for NASA High Data Rate Applications

      Gray, J. S.; Harris Electronic Systems Division (International Foundation for Telemetering, 1976-09)
      Two bit synchronizer-signal conditioners (BSSC) developed for NASA high data rate applications such as earth resources monitoring are described. One BSSC is centered at 120 Mb/s and the other at 240 Mb/s. These subsystems are featured out of the total hardware developed* because the BSSC is such a key subsystem in determining overall system statistical performance. These units represent an evolution of high data rate technology toward the versatile any data rate BSSC's available at low data rates. Numerous inputs/outputs, control functions, indicators, plus the ability to minimize the effects of various signal perturbations are provided. Examples of allowed perturbations are input level variations, bit rate variance static and dynamic, baseline, transition density, bandlimiting, etc., as well as noise. Emphasis in the past has been primarily concerned only with noise.
    • 136 MHz Interferometer Error Due to Galactic Nucleus

      Kyriakopoulos, N.; Taylor, R. E.; Reich, R. (International Foundation for Telemetering, 1971-09)
      Spacecraft orbits are determined by means of direction cosines generated from electrical phase data provided by the 136 MHz Minitrack radio-interferometer system. The phase data thus determine the direction cosines of the position vector as the spacecraft passes across Minitrack's fan-shaped antenna beam. Uncertainties introduced into the output electrical phase due to undesirable interfering sources limit the basic accuracy of the Minitrack system. Although a knowledge of the spacecraft orbital dynamics may be used to improve the accuracy of the system, nevertheless there remains a fundamental error due to interference caused by the passage of the galactic nucleus. This paper determines the error due to a distributed noise source. Furthermore, it develops an expression for the lower bound of the phase error when the noise source is not uniformly distributed across a zenith-pointed fan beam. In addition, it determines the threshold of the Minitrack input power levels below which the electrical phase is no longer determined unambiguously. The effect of the passage of the galactic nucleus coincident with the presence of a space craft has been analyzed, and the corresponding phase error determined.
    • 1553 Data BUS/PCM Multiplexer System

      Breedlove, Phil; Malone, Earl; Loral/Conic; Boeing Aerospace (International Foundation for Telemetering, 1989-11)
      A Telemetry system which integrates 1553 Bus data, DualSimplex bus data, vehicle performance data, and environmental sensor data multiplexing encompasses many interfacing constraints. The Engineering design considerations and hardware constraints required to implement this system are presented in this paper.

      Grace, Thomas; Roach, John; Naval Air Systems Command; Teletronics Technology Corporation (International Foundation for Telemetering, 2006-10)
      CTEIP has launched the integrated Network Enhanced Telemetry (iNET) project to foster advances in networking and telemetry technology to meet emerging needs of major test programs as well as within the Major Range and Test Facility Base’s. This paper describes one objective of the vNET concept demonstration to provide a test vehicle instrumentation network architecture that can support additional capabilities for data access to the test vehicle. Specifically, this paper addresses the expansion of the current concept demonstration with the incorporation of the IEEE- 1588 standard as the basis for a network time distribution mechanism. Near-term network-based data acquisition systems will likely consist of a mix of standard IRIG 106 timekeeping and IEEE- 1588 timekeeping; in this paper we will examine the ramifications of using the two approaches with the same test vehicle instrumentation system.

      Huang, Thomas K.; Rhodes, Richard A.; Mehta, Jayanti; Hughes Aircraft Co. (International Foundation for Telemetering, 1981-10)
      An experimental power amplifier using GaAs FETs was built and tested. This power amplifier delivered 16 watts of RF output power in mid Ku-Band. It employed 88 GaAs FET devices and demonstrated 40 dB of gain with 12% DC to RF efficiency. The design considerations of power output, efficiency, bandwidth, size and thermal description are discussed from the viewpoint of potential space application. Also discussed are combining philosophy and package layout. Actual experimental results are presented.
    • A 17:1 Dual Band Circularly Polarized Focused Two-Channel Monopulse Tracking System

      Lantz, Paul A.; Chadwick, George G.; Hurlburt, Roderic W.; Yaminy, Roger R.; NASA Goddard Space Center; Radiation Systems, Incorporated (International Foundation for Telemetering, 1969-09)
      This paper describes a dual circularly polarized feed system for operation In incremental bands over the frequency range from 136 to 2300 MHz. The characteristics of a 60-foot parabola excited by the feed system are discussed. Tracking data for this system have also been obtained using a helicopter, the Apollo VIII vehicle, and Cassiopeia A. It will be shown that the two-channel monopulse technique allows the use of antenna feeds which, in turn, provide sidelobes of greater than -20 db relative to the main lobe peak for all frequencies. This sidelobe performance reflects the fact that the feed is approximately focused at all frequencies, unlike its earlier log periodic type predecessors. The characteristics of a similar feed used in the Apollo Range Instrumented Aircraft (A/RIA) will also be described in this paper.
    • 19mm Rotary Digital Data and Instrumentation Recording

      DeFrancesco, Richard E.; Honeywell (International Foundation for Telemetering, 1988-10)
      A new family of recording devices has emerged which are user-friendly, 19mm cartridgebased use a MIL-STD format, and are capable of high transfer rates for diverse applications.
    • A 2-kw S-Band Re-Entry Telemetry System

      Trapp, D. L.; Williams, P. K.; Sandia Laboratories (International Foundation for Telemetering, 1971-09)
      Instrumentation of high-velocity re-entry rocket systems at Sandia Laboratories has been complicated because of dependence on onboard magnetic tape recorders to store data until the carrier emerges from the radiofrequency blackout. This paper describes an approach designed to minimize the effect of the RF blackout by means of employing a sampled data system the output of which consists of 1-μsec pulses of 2-kw RF power level. The effort was initiated in the spring of 1970 for the purpose of obtaining real-time data during the re-entry blackout phase of a Sandia re-entry flight test. Re-entry velocities in the vicinity of 25,000 fps are expected.
    • 20 GHz Active Aperture for Communication Satellites

      Jones, Donald E.; Motorola, Inc. (International Foundation for Telemetering, 1980-10)
      The trend to higher frequencies for satellite to earth communications, together with requirements for increased reliability and graceful degradation, has resulted in the need for a 20 GHz active aperture transmitting array. In this paper the preliminary design of such an array is discussed. The array is designed for 35 dB of gain and -30 dB sidelobes. Quantized amplitude tapering, gain distribution, phase shifter quantization, prime power requirements, array and element trade-offs are discussed. The impact of multiple beam operation for frequency reuse is addressed.

      Sokolov, V.; Saunier, P.; Bennett, R.C.; Lehmann, R.E.; Texas Instruments Incorporated Central Research Laboratories (International Foundation for Telemetering, 1981-10)
      A GaAs FET power amplifier module operating in K-band is described. The module has integral input and output WR-51 waveguide ports and incorporates a pair of low-loss waveguide to microstrip transitions. Single-stage and multi-stage microstrip FET amplifiers are fabricated on individual copper carrier blocks incorporating in-package impedance matching. Six packaged amplifiers are cascaded to achieve a 0.5 W, 30 dB gain amplifier module operating over the 17.7-20.2 GHz band.