Sample records for wff flight modem

  1. Telemetry Tracking and Control Through Commercial LEO Satellites

    NASA Technical Reports Server (NTRS)

    Streich, Ronald C.; Morgan, Dwayne R.; Bull, Barton B.; Grant, Charles E.; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF in Virginia have successfully tested commercial LEO communications satellites for sounding rocket, balloon and aircraft flight TT&C. The Flight Modern became a GSFC/WFF Advanced Range Technology Initiative (ARTI) in an effort to streamline TT&C capability to the user community at low cost. Ground tests of the Flight Modem verified duplex communications quality of service and measured transmission latencies. These tests were completed last year and results reported in the John Hopkins University (JHU) Applied Physics Laboratory (APL) 4th International Symposium on Reducing Spacecraft Costs for Ground Systems and Operations. The second phase of the Flight Modem baseline test program was a demonstration of the ruggedized version of the WFF Flight Modem flown on a sounding rocket launched it the Swedish rocket range (Esrangc) near Kiruna, Sweden, with results contained in this paper. Aircraft flight tests have been and continue to be conducted. Flights of opportunity are being actively pursued with other centers, ranges and users at universities. The WFF Flight Modem contains a CPS receiver to provide vehicle position for tracking and vehicle recovery. The system architecture, which integrates antennas, CPS receiver, commercial satellite packet data modem and a single board computer with custom software, is described. Small satellite use of the WFF Flight Modem is also being investigated, The Flight Modem provides an independent vehicle position source for Range Safety applications. The LEO communication system contains a coarse position location system, which is compared to GPS ace acy. This comparison allows users, to determine the need for a CPS receiver in addition to the satellite packet data modem for their application.

  2. TT and C - First TDRSS, Then Commercial GEO and Big LEO and Now through LEO

    NASA Technical Reports Server (NTRS)

    Morgan, Dwayne; Bull, Barton; Grant, Charles; Streich, Ronald; Powers, Edward I. (Technical Monitor)

    2001-01-01

    The advent of low earth orbit (LEO) commercial communications satellites provides an opportunity to dramatically reduce Telemetry Tracking and Control (TT&C) costs of launch vehicles and Unpiloted Aerial Vehicles (UAVs) by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia have successfully used commercial GEO & Big LEO communications satellites for Long Duration Balloon flight TT&C. In addition, TDRSS capability for these balloons has been developed by WFF for the Ultra Long Duration Balloons with the first test flight launch in January 2001 for one global circumnavigation at 120,000 feet altitude launched from Alice Springs. Australia. Numerous other low cost applications can new utilize the commercial LEO satellites for TT&C. The Flight Modern became a GSFC/WFF Advanced Range Technology Initiative (ARTI) in an effort to streamline TT&C capability to the user community at low cost. Phase I ground tests of The Flight Modem verified downlink communications quality of service and measured transmission latencies. These tests were completed last year, Phase II consisting of aircraft flight tests provide much of the data presented in this paper. Phase III of the Flight Modern baseline test program is a demonstration of the ruggedized version of the WFF Flight Modem flown on one sounding rocket launched from Sweden. Flights of opportunity have been and are being actively pursued with other centers, ranges and users at universities. The WFF goal is to reduce TT&C costs by providing a low cost COTS Flight Modem with a User Handbook containing system capability and limitation descriptions. Additionally, since data transmission is by packetized Internet Protocol (IP), data can be received and commands initialed from practically any location with no infrastructure. The WFF, like most ranges, has been using GPS receivers on sounding rockets and long duration balloons for several years, The WFF Flight Modem contains a GPS receiver to provide vehicle position for tracking and vehicle recovery. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem. and a single board computer with custom software is described and a number of technical challenges are discussed along with the plan for their resolution. These include antenna development, high Doppler rates, reliability, environmental ruggedness, hand over between satellites and data security. An aggressive test plan is included which in addition to environmental Testing measures bit error rate latency and antenna patterns. Additional flight tests are planned far the near future on aircraft, long duration balloons and sounding rockets and these results as well as the current status of the project arc reported. Use of the WFF Flight Modem on small satellites is also being pursued. The LEO satellite constellation altitude above 1400 km is not an obstacle because most spacecraft do not require continuous Communications. The challenge is scheduling where store and forward techniques for command are required and downlink when the communications link allows connection (above 60 percent of the time depending on the satellite altitude). Sophisticated scheduling techniques utilizing 2-line orbital element sets available on the NASA/NORAD Internet site could be implemented for rare special cases. The current 9600 baud rate of the LEO communications link may be increased With special techniques that are planned for development in the WFF Flight Modem project.

  3. Telemetry Tracking & Control (TT&C) - First TDRSS, then Commercial GEO & Big LEO and Now Through LEO

    NASA Technical Reports Server (NTRS)

    Morgan, Dwayne R.; Streich, Ron G.; Bull, Barton; Grant, Chuck; Power, Edward I. (Technical Monitor)

    2001-01-01

    The advent of low earth orbit (LEO) commercial communication satellites provides an opportunity to dramatically reduce Telemetry, Tracking and Control (TT&C) costs of launch vehicles, Unpiloted Aerial Vehicles (UAVs), Research Balloons and spacecraft by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center's Wallops Flight Facility (GSFC\\WFF) have successfully used commercial Geostationary Earth Orbit (GEO) and Big LEO communications satellites for Long Duration Balloon Flight TT&C. The Flight Modem is a GSFC\\WFF Advanced Range Technology initiative (ARTI) designed to streamline TT&C capability in the user community of these scientific data gathering platforms at low cost. Making use of existing LEO satellites and adapting and ruggedized commercially available components; two-way, over the horizon communications may be established with these vehicles at great savings due to reduced infrastructure. Initially planned as a means for permitting GPS data for tracking and recovery of sounding rocket and balloon payloads, expectations are that the bandwidth can soon be expanded to allow more comprehensive data transfer. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem and a single board computer with custom software is described and technical challenges are discussed along with the plan for their resolution. A three-phase testing and development plan is outlined and the current results are reported. Results and status of ongoing flight tests on aircraft and sounding rockets are reported. Future applications on these platforms and the potential for satellite support are discussed along with an analysis of cost effectiveness of this method vs. other tracking and data transmission schemes.

  4. Space Based Communications

    NASA Technical Reports Server (NTRS)

    Simpson, James; Denson, Erik; Valencia, Lisa; Birr, Richard

    2003-01-01

    Current space lift launches on the Eastern and Western Range require extensive ground-based real-time tracking, communications and command/control systems. These are expensive to maintain and operate and cover only limited geographical areas. Future spaceports will require new technologies to provide greater launch and landing opportunities, support simultaneous missions, and offer enhanced decision support models and simulation capabilities. These ranges must also have lower costs and reduced complexity while continuing to provide unsurpassed safety to the public, flight crew, personnel, vehicles and facilities. Commercial and government space-based assets for tracking and communications offer many attractive possibilities to help achieve these goals. This paper describes two NASA proof-of-concept projects that seek-to exploit the advantages of a space-based range: Iridium Flight Modem and Space-Based Telemetry and Range Safety (STARS). Iridium Flight Modem uses the commercial satellite system Iridium for extremely low cost, low rate two-way communications and has been successfully tested on four aircraft flights. A sister project at Goddard Space Flight Center's (GSFC) Wallops Flight Facility (WFF) using the Globalstar system has been tested on one rocket. The basic Iridium Flight Modem system consists of a L1 carrier Coarse/Acquisition (C/A)-Code Global Positioning System (GPS) receiver, an on-board computer, and a standard commercial satellite modem and antennas. STARS uses the much higher data rate NASA owned Tracking and Data Relay Satellite System (TDRSS), a C/A-Code GPS receiver, an experimental low-power transceiver, custom built command and data handler processor, and digitized flight termination system (FTS) commands. STARS is scheduled to fly on an F-15 at Dryden Flight Research Center in the spring of 2003, with follow-on tests over the next several years.

  5. Goodard Space Flight Center/Wallops Flight Facility airborne geoscience support capability

    NASA Technical Reports Server (NTRS)

    Navarro, Roger L.

    1991-01-01

    Goddard Space Flight Center's Wallops Facility (GSFC/WFF), operates six aircraft which are used as airborne geoscience platforms. The aircraft complement consists of two UH-1B helicopters, one twin engine Skyvan, one twin jet T-39, and two four engine turboprop aircraft (P-3 and Electra) offering the research community a wide range of payload, altitude, speed, and range capabilities. WFF's support to a principal investigator include mission planning of all supporting elements, installation of equipment on the aircraft, fabrication of brackets, and adapters as required to adapt payloads to the aircraft, and planning of mission profiles to meet science objectives. The flight regime includes local, regional, and global missions. The WFF aircraft serve scientists at GSFC, other NASA centers, other government agencies, and universities. The WFF mode of operation features the walk on method of conducting research projects. The principal investigator requests aircraft support by letter to WFF and after approval is granted, works with the assigned mission manager to plan all phases of project support. The instrumentation is installed in WFF electronics racks, mounted on the aircraft, the missions are flown, and the equipment is removed when the scientific objectives are met. The principal investigator reimburses WFF for each flight hours, any overtime and travel expenses generated by the project, and for other mission-related expenses such as aircraft support services required at deployment bases.

  6. Agreements/subagreements Applicable to Wallops, 12 Nov. 1991

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The status of space science agreements are noted. A general overview of the Wallops Flight Facility (WFF) is given. The geography, history, and mission of the facility are briefly surveyed. Brief accounts are given of NASA earth science activities at the WFF, including atmospheric dynamics, atmospheric optics, ocean physics, microwave altimetry, ocean color research, wind-wave-current interaction, flight support activities, the Sounding Rocket Program, and the NASA Balloon Program. Also discussed are the WFF launch range, the research airport, aircraft airborne science, telemetry, data systems, communications, and command and control.

  7. WFF TOPEX Software Documentation Overview, May 1999. Volume 2

    NASA Technical Reports Server (NTRS)

    Brooks, Ronald L.; Lee, Jeffrey

    2003-01-01

    This document provides an overview'of software development activities and the resulting products and procedures developed by the TOPEX Software Development Team (SWDT) at Wallops Flight Facility, in support of the WFF TOPEX Engineering Assessment and Verification efforts.

  8. Radar data smoothing filter study

    NASA Technical Reports Server (NTRS)

    White, J. V.

    1984-01-01

    The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

  9. IRVE-II Post-Flight Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    O'Keefe, Stephen A.; Bose, David M.

    2010-01-01

    NASA s Inflatable Re-entry Vehicle Experiment (IRVE) II successfully demonstrated an inflatable aerodynamic decelerator after being launched aboard a sounding rocket from Wallops Flight Facility (WFF). Preliminary day of flight data compared well with pre-flight Monte Carlo analysis, and a more complete trajectory reconstruction performed with an Extended Kalman Filter (EKF) approach followed. The reconstructed trajectory and comparisons to an attitude solution provided by NASA Sounding Rocket Operations Contract (NSROC) personnel at WFF are presented. Additional comparisons are made between the reconstructed trajectory and pre and post-flight Monte Carlo trajectory predictions. Alternative observations of the trajectory are summarized which leverage flight accelerometer measurements, the pre-flight aerodynamic database, and on-board flight video. Finally, analysis of the payload separation and aeroshell deployment events are presented. The flight trajectory is reconstructed to fidelity sufficient to assess overall project objectives related to flight dynamics and overall, IRVE-II flight dynamics are in line with expectations

  10. Green Propellant Landing Demonstration at U.S. Range

    NASA Technical Reports Server (NTRS)

    Mulkey, Henry W.; Miller, Joseph T.; Bacha, Caitlin E.

    2016-01-01

    The Green Propellant Loading Demonstration (GPLD) was conducted December 2015 at Wallops Flight Facility (WFF), leveraging work performed over recent years to bring lower toxicity hydrazine replacement green propellants to flight missions. The objective of this collaboration between NASA Goddard Space Flight Center (GSFC), WFF, the Swedish National Space Board (SNSB), and Ecological Advanced Propulsion Systems (ECAPS) was to successfully accept LMP-103S propellant at a U.S. Range, store the propellant, and perform a simulated flight vehicle propellant loading. NASA GSFC Propulsion (Code 597) managed all aspects of the operation, handling logistics, preparing the procedures, and implementing the demonstration. In addition to the partnership described above, Moog Inc. developed an LMP-103S propellant-compatible titanium rolling diaphragm flight development tank and loaned it to GSFC to act as the GPLD flight vessel. The flight development tank offered the GPLD an additional level of flight-like propellant handling process and procedures. Moog Inc. also provided a compatible latching isolation valve for remote propellant expulsion. The GPLD operation, in concert with Moog Inc. executed a flight development tank expulsion efficiency performance test using LMP-103S propellant. As part of the demonstration work, GSFC and WFF documented Range safety analyses and practices including all elements of shipping, storage, handling, operations, decontamination, and disposal. LMP-103S has not been previously handled at a U.S. Launch Range. Requisite for this activity was an LMP-103S Risk Analysis Report and Ground Safety Plan. GSFC and WFF safety offices jointly developed safety documentation for application into the GPLD operation. The GPLD along with the GSFC Propulsion historical hydrazine loading experiences offer direct comparison between handling green propellant versus safety intensive, highly toxic hydrazine propellant. These described motives initiated the GPLD operation in order to investigate the handling and process safety variances in project resources between LMP-103S and typical in-space propellants. The GPLD risk reduction operation proved successful for many reasons including handling the green propellant at a U.S. Range, loading and pressurizing a flight-like tank, expelling the propellant, measuring the tank expulsion efficiency, and most significantly, GSFC propulsion personnel's new insight into the LMP-103S propellant handling details.

  11. Green Propellant Loading Demonstration at U.S. Range

    NASA Technical Reports Server (NTRS)

    Mulkey, Henry W.; Miller, Joseph T.; Bacha, Caitlin E.

    2016-01-01

    The Green Propellant Loading Demonstration (GPLD) was conducted December 2015 at Wallops Flight Facility (WFF), leveraging work performed over recent years to bring lower toxicity hydrazine replacement green propellants to flight missions. The objective of this collaboration between NASA Goddard Space Flight Center (GSFC), WFF, the Swedish National Space Board (SNSB), and Ecological Advanced Propulsion Systems (ECAPS) was to successfully accept LMP-103S propellant at a U.S. Range, store the propellant, and perform a simulated flight vehicle propellant loading. NASA GSFC Propulsion (Code 597) managed all aspects of the operation, handling logistics, preparing the procedures, and implementing the demonstration. In addition to the partnership described above, Moog Inc. developed an LMP-103S propellant-compatible titanium rolling diaphragm flight development tank and loaned it to GSFC to act as the GPLD flight vessel. The flight development tank offered the GPLD an additional level of flight-like propellant handling process and procedures. Moog Inc. also provided a compatible latching isolation valve for remote propellant expulsion. The GPLD operation, in concert with Moog Inc. executed a flight development tank expulsion efficiency performance test using LMP-103S propellant. As part of the demonstration work, GSFC and WFF documented Range safety analyses and practices including all elements of shipping, storage, handling, operations, decontamination, and disposal. LMP-103S has not been previously handled at a U.S. Launch Range. Requisite for this activity was an LMP-103S Risk Analysis Report and Ground Safety Plan. GSFC and WFF safety offices jointly developed safety documentation for application into the GPLD operation. The GPLD along with the GSFC Propulsion historical hydrazine loading experiences offer direct comparison between handling green propellant versus safety intensive, highly toxic hydrazine propellant. These described motives initiated the GPLD operation in order to investigate the handling and process safety variances in project resources between LMP-103S and typical in-space propellants. The GPLD risk reduction operation proved successful for many reasons including handling the green propellant at a U.S. Range, loading and pressurizing a flight-like tank, expelling the propellant, measuring the tank expulsion efficiency, and most significantly, GSFC propulsion personnel's new insight into the LMP-103S propellant handling details.

  12. A Space Based Internet Protocol System for Sub-Orbital Tracking and Control

    NASA Technical Reports Server (NTRS)

    Bull, Barton; Grant, Charles; Morgan, Dwayne; Streich, Ron; Bauer, Frank (Technical Monitor)

    2001-01-01

    Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia are responsible for the overall management of the NASA Sounding Rocket Program. Payloads are generally in support of NASA's Space Science Enterprise's missions and return a variety of scientific data as well as providing a reasonably economical means of conducting engineering tests for instruments and devices used on satellites and other spacecraft. The fifteen types of sounding rockets used by NASA can carry payloads of various weights to altitudes from 50 km to more than 1,300 km. Launch activities are conducted not only from established missile ranges, but also from remote locations worldwide requiring mobile tracking and command equipment to be transported and set up at considerable expense. The advent of low earth orbit (LEO) commercial communications satellites provides an opportunity to dramatically reduce tracking and control costs of launch vehicles and Unpiloted Aerial Vehicles (UAVs) by reducing or eliminating this ground infrastructure. Additionally, since data transmission is by packetized Internet Protocol (IP), data can be received and commands initiated from practically any location. A low cost Commercial Off The Shelf (COTS) system is currently under development for sounding rockets which also has application to UAVs and scientific balloons. Due to relatively low data rate (9600 baud) currently available, the system will first be used to provide GPS data for tracking and vehicle recovery. Range safety requirements for launch vehicles usually stipulate at least two independent tracking sources. Most sounding rockets flown by NASA now carry GPS receivers that output position data via the payload telemetry system to the ground station. The Flight Modem can be configured as a completely separate link thereby eliminating requirement for tracking radar. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem, and a single board computer with custom software is described along with the technical challenges and the plan for their resolution. These include antenna development, high Doppler rates, reliability, environmental ruggedness, hand over between satellites and data security. An aggressive test plan is included which in addition to environmental testing measures bit error rate, latency and antenna patterns. Actual flight tests are planned for the near future on aircraft, long duration balloons and sounding rockets and these results as well as the current status of the project are reported.

  13. A Space Based Internet Protocol System for Launch Vehicle Tracking and Control

    NASA Technical Reports Server (NTRS)

    Bull, Barton; Grant, Charles; Morgan, Dwayne; Streich, Ron; Bauer, Frank (Technical Monitor)

    2001-01-01

    Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia are responsible for the overall management of the NASA Sounding Rocket and Scientific Balloon Programs. Payloads are generally in support of NASA's Space Science Enterprise's missions and return a variety of scientific data as well as providing a reasonably economical means of conducting engineering tests for instruments and devices used on satellites and other spacecraft. Sounding rockets used by NASA can carry payloads of various weights to altitudes from 50 km to more than 1,300 km. Scientific balloons can carry a payload weighing as much as 3,630 Kg to an altitude of 42 km. Launch activities for both are conducted not only from established ranges, but also from remote locations worldwide requiring mobile tracking and command equipment to be transported and set up at considerable expense. The advent of low earth orbit (LEO) commercial communications satellites provides an opportunity to dramatically reduce tracking and control costs of these launch vehicles and Unpiloted Aerial Vehicles (UAVs) by reducing or eliminating this ground infrastructure. Additionally, since data transmission is by packetized Internet Protocol (IP), data can be received and commands initiated from practically any location. A low cost Commercial Off The Shelf (COTS) system is currently under development for sounding rockets that also has application to UAVs and scientific balloons. Due to relatively low data rate (9600 baud) currently available, the system will first be used to provide GPS data for tracking and vehicle recovery. Range safety requirements for launch vehicles usually stipulate at least two independent tracking sources. Most sounding rockets flown by NASA now carry GP receivers that output position data via the payload telemetry system to the ground station. The Flight Modem can be configured as a completely separate link thereby eliminating the requirement for tracking radar. The system architecture that integrates antennas, GPS receiver, commercial satellite packet data modem, and a single board computer with custom software is described along with the technical challenges and the plan for their resolution. These include antenna development, high Doppler rates, reliability, environmental ruggedness, hand over between satellites, and data security. An aggressive test plan is included which, in addition to environmental testing, measures bit error rate, latency and antenna patterns. Actual launches on a sounding rocket and various aircraft flights have taken place. Flight tests are planned for the near future on aircraft, long duration balloons and sounding rockets. These results, as well as the current status of the project, are reported.

  14. Overview of the NASA Wallops Flight Facility Mobile Range Control System

    NASA Technical Reports Server (NTRS)

    Davis, Rodney A.; Semancik, Susan K.; Smith, Donna C.; Stancil, Robert K.

    1999-01-01

    The NASA GSFC's Wallops Flight Facility (WFF) Mobile Range Control System (MRCS) is based on the functionality of the WFF Range Control Center at Wallops Island, Virginia. The MRCS provides real time instantaneous impact predictions, real time flight performance data, and other critical information needed by mission and range safety personnel in support of range operations at remote launch sites. The MRCS integrates a PC telemetry processing system (TELPro), a PC radar processing system (PCDQS), multiple Silicon Graphics display workstations (IRIS), and communication links within a mobile van for worldwide support of orbital, suborbital, and aircraft missions. This paper describes the MRCS configuration; the TELPro's capability to provide single/dual telemetry tracking and vehicle state data processing; the PCDQS' capability to provide real time positional data and instantaneous impact prediction for up to 8 data sources; and the IRIS' user interface for setup/display options. With portability, PC-based data processing, high resolution graphics, and flexible multiple source support, the MRCS system is proving to be responsive to the ever-changing needs of a variety of increasingly complex missions.

  15. Space-Based Range

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Space-Based Range (SBR), previously known as Space-Based Telemetry and Range Safety (STARS), is a multicenter NASA proof-of-concept project to determine if space-based communications using NASA's Tracking and Data Relay Satellite System (TDRSS) can support the Range Safety functions of acquiring tracking data and generating flight termination signals, while also providing broadband Range User data such as voice, video, and vehicle/payload data. There was a successful test of the Range Safety system at Wallops Flight Facility (WFF) on December 20, 2005, on a two-stage Terrier-Orion spin-stabilized sounding rocket. SBR transmitted GPS tracking data and maintained links with two TDRSS satellites simultaneously during the 10-min flight. The payload section deployed a parachute, landed in the Atlantic Ocean about 90 miles downrange from the launch site, and was successfully recovered. During the Terrier-Orion tests flights, more than 99 percent of all forward commands and more than 95 percent of all return frames were successfully received and processed. The time latency necessary for a command to travel from WFF over landlines to White Sands Complex and then to the vehicle via TDRSS, be processed onboard, and then be sent back to WFF was between 1.0 s and 1.1 s. The forward-link margins for TDRS-10 (TDRS East [TDE]) were 11 dB to 12 dB plus or minus 2 dB, and for TDRS-4 (TDRS Spare [TDS]) were 9 dB to 10 dB plus or minus 1.5 dB. The return-link margins for both TDE and TDS were 6 dB to 8 dB plus or minus 3 dB. There were 11 flights on an F-15B at Dryden Flight Research Center (DFRC) between November 2006 and February 2007. The Range User system tested a 184-element TDRSS Ku-band (15 GHz) phased-array antenna with data rates of 5 Mbps and 10 Mbps. This data was a combination of black-and-white cockpit video, Range Safety tracking and transceiver data, and aircraft and antenna controller data streams. IP data formatting was used.

  16. 76 FR 19122 - Record of Decision (ROD) for Authorizing the Use of Outer Continental Shelf (OCS) Sand Resources...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... Aeronautics and Space Administration's Wallops Flight Facility Shoreline Restoration and Infrastructure... authorize the use of OCS sand resources in National Aeronautics and Space Administration's (NASA's) Wallops... infrastructure on the WFF (such as rocket launch pads, runways, and launch control centers) valued at over $1...

  17. The Electronic Flight Bag: A Multi-Function Tool for the Modern Cockpit

    DTIC Science & Technology

    2002-08-01

    56K Modem , Sound Card, Touchscreen USB, PCMCIA, IR, 56K Modem , Sound Card, Touchscreen USB, IrDA, PCMCIA, Wireless LAN, Touchscreen, Integrated...card, internal modem and augmented internal battery. It is designed to complement the PID for use in the classroom at home or on the road.59

  18. 76 FR 12403 - Office of Commercial Space Transportation; Notice of Availability of the Finding of No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... necessary in the FONSI. NASA has posted the 2005 EA on the internet at http://sites.wff.nasa.gov/code250... Aeronautics and Space Administration (NASA) Final Site-Wide Environmental Assessment (EA) for Wallops Flight...). Under the Proposed Action in the 2005 EA, NASA would construct new facilities, demolish old facilities...

  19. Wallops Low Elevation Link Analysis for the Constellation Launch/Ascent Links

    NASA Technical Reports Server (NTRS)

    Cheung, Keith; Ho, C.; Kantak, A.; Lee, C.; Tye, R.; Richards, E.; Sham, C.; Schlesinger, A.; Barritt, B.

    2011-01-01

    To execute the President's Vision for Space Exploration, the Constellation Program (CxP) was formed to build the next generation spacecraft Orion and launch vehicles Ares, to transport human and cargo to International Space Station (ISS), moon, and Mars. This paper focuses on the detailed link analysis for Orion/Ares s launch and ascent links with Wallops 11.3m antenna (1) Orion's Dissimilar Voice link: 10.24 Kbps, 2-way (2) Ares Developmental Flight Instrument link, 20 Mbps, downlink. Three launch trajectories are considered: TD7-E, F (Feb), and G (Aug). In certain launch scenarios, the critical events of main engine cutoff (MECO) and Separation occur during the low elevation regime of WFF s downrange -- less than 5 degree elevation angle. The goal of the study is to access if there is enough link margins for WFF to track the DV and DFI links.

  20. Enabling a Science Support Structure for NASAs Global Hawk UASs

    NASA Technical Reports Server (NTRS)

    Sullivan, Donald V.

    2014-01-01

    In this paper we describe the information technologies developed by NASA for the Winter/Spring 2013/2014, and Fall 2014, NASA Earth Venture Campaigns, Hurricane and Severe Storm Sentinel (HS3) and Airborne Tropical TRopopause EXperiment (ATTREX). These campaigns utilized Global Hawk UAS vehicles equipped at the NASA Armstrong (previously Dryden) Flight Research Facility (AFRC), Edwards Air Force Base, California, and operated from there, the NASA Wallops Flight Facility (WFF), Virginia, and Anderson Air Force Base (AAFB), Guam. Part of this enabling infrastructure utilized a layer 2 encrypted terrestrial Virtual Local Area Network (VLAN) that, at times, spanned greater than ten thousand miles (AAFB <-> AFRC <-> WFF) and was routed over geosynchronous Ku band communication Satellites directly to the aircraft sensor network. This infrastructure enabled seamless hand off between Satellites, and Satellite ground stations in Guam, California and Virginia, so allowing simultaneous Aircraft Command and Control and Science operations from remote locations. Additionally, we will describe the other elements of this infrastructure, from on-board geo-enabled databases, to real time communications directly from the instruments (in some cases, more than twelve were carried, and simultaneously operated, on one aircraft) to the researchers and other interested parties, world wide.

  1. Heavy Lift Vehicle (HLV) Avionics Flight Computing Architecture Study

    NASA Technical Reports Server (NTRS)

    Hodson, Robert F.; Chen, Yuan; Morgan, Dwayne R.; Butler, A. Marc; Sdhuh, Joseph M.; Petelle, Jennifer K.; Gwaltney, David A.; Coe, Lisa D.; Koelbl, Terry G.; Nguyen, Hai D.

    2011-01-01

    A NASA multi-Center study team was assembled from LaRC, MSFC, KSC, JSC and WFF to examine potential flight computing architectures for a Heavy Lift Vehicle (HLV) to better understand avionics drivers. The study examined Design Reference Missions (DRMs) and vehicle requirements that could impact the vehicles avionics. The study considered multiple self-checking and voting architectural variants and examined reliability, fault-tolerance, mass, power, and redundancy management impacts. Furthermore, a goal of the study was to develop the skills and tools needed to rapidly assess additional architectures should requirements or assumptions change.

  2. Airborne water vapor DIAL research: System development and field measurements

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

    1992-01-01

    This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

  3. The Mission Planning Lab: A Visualization and Analysis Tool

    NASA Technical Reports Server (NTRS)

    Daugherty, Sarah C.; Cervantes, Benjamin W.

    2009-01-01

    Simulation and visualization are powerful decision making tools that are time-saving and cost-effective. Space missions pose testing and e valuation challenges that can be overcome through modeling, simulatio n, and visualization of mission parameters. The National Aeronautics and Space Administration?s (NASA) Wallops Flight Facility (WFF) capi talizes on the benefits of modeling, simulation, and visualization to ols through a project initiative called The Mission Planning Lab (MPL ).

  4. GEOSAT Follow-On (GFO) Altimeter Document Series. Volume 5; Version 1; GFO Radar Altimeter Processing at Wallops Flight Facility

    NASA Technical Reports Server (NTRS)

    Lockwood, Dennis W.; Conger, A. M.

    2003-01-01

    This document is a compendium of the WFF GFO Software Development Team's knowledge regarding of GDO CAL/VAL Data. It includes many elements of a requirements document, a software specification document, a software design document, and a user's guide. In the more technical sections, this document assumes the reader is familiar with GFO and its CAL/VAL Data.

  5. Flight Performance of the Inflatable Reentry Vehicle Experiment 3

    NASA Technical Reports Server (NTRS)

    Dillman, Robert; DiNonno, John; Bodkin, Richard; Gsell, Valerie; Miller, Nathanael; Olds, Aaron; Bruce, Walter

    2013-01-01

    The Inflatable Reentry Vehicle Experiment 3 (IRVE-3) launched July 23, 2012, from NASA Wallops Flight Facility (WFF) on a Black Brant XI suborbital sounding rocket and successfully performed its mission, demonstrating the survivability of a hypersonic inflatable aerodynamic decelerator (HIAD) in the reentry heating environment and also illustrating the effect of an offset center of gravity on the HIAD's lift-to-drag ratio. IRVE-3 was a follow-on to 2009's IRVE-II mission, which demonstrated exo-atmospheric inflation, reentry survivability - without significant heating - and the aerodynamic stability of a HIAD down to subsonic flight conditions. NASA Langley Research Center is leading the development of HIAD technology for use on future interplanetary and Earth reentry missions.

  6. Applied Meteorology Unit (AMU) Quarterly Report Fourth Quarter FY-14

    NASA Technical Reports Server (NTRS)

    Bauman, William H.; Crawford, Winifred C.; Watson, Leela R.; Shafer, Jaclyn

    2014-01-01

    Ms. Crawford completed the final report for the dual-Doppler wind field task. Dr. Bauman completed transitioning the 915-MHz and 50-MHz Doppler Radar Wind Profiler (DRWP) splicing algorithm developed at Marshall Space Flight Center (MSFC) into the AMU Upper Winds Tool. Dr. Watson completed work to assimilate data into model configurations for Wallops Flight Facility (WFF) and Kennedy Space Center/Cape Canaveral Air Force Station (KSC/CCAFS). Ms. Shafer began evaluating the a local high-resolution model she had set up previously for its ability to forecast weather elements that affect launches at KSC/CCAFS. Dr. Watson began a task to optimize the data-assimilated model she just developed to run in real time.

  7. A study on rheological characteristics of roller milled fenugreek fractions.

    PubMed

    Sakhare, Suresh D; Inamdar, Aashitosh A; Prabhasankar, P

    2016-01-01

    Fenugreek seeds were fractionated by roller milling to get various fractions. The roller milled fractions and whole fenugreek flour (WFF) were evaluated for the flow behavior and time-dependent flow properties using a rotational viscometer at the temperatures of 10-60 (0)C. The samples subjected to a programmed shear rate increase linearly from 0 to 300 s(-1) in 3 min and successive decrease linearly shear rate from 300 s(-1) to 0 in 3 min. The roller milled fractions and WFF paste exhibited non-Newtonian pseudoplastic behavior. Difference in hysteresis loop area was observed among the roller milled fractions and WFF, being more noticeable at lower temperatures. Power law and Casson models were used to predict flow properties of samples. The power law model described well the flow behavior of the roller milled fractions and WFF at temperatures tested. Except flour (FL) fraction, consistency coefficient, m, increased with the temperature both in the forward and backward measurements. The roller milled fractions and WFF exhibited rheopectic behavior that increased viscosity with increasing the shear speed and the temperature. For all the sample tested, initial shear stress increased with increase in shear rate and temperature.

  8. HaloSat- A CubeSat to Study the Hot Galactic Halo

    NASA Astrophysics Data System (ADS)

    Kaaret, Philip

    We propose to develop, build, and fly HaloSat, a CubeSat capable of measuring the oxygen line emission from the hot Galactic halo. A dedicated CubeSat enables an instrument design and observing strategy to maximize the halo signal while minimizing foregrounds from solar wind charge exchange interactions within the solar system. We will use HaloSat to map the distribution of hot gas in the Milky Way and determine whether it fills an extended, and thus massive halo, or whether the halo is compact, and thus does not contribute significantly to the total mass of the Milky Way. HaloSat can be accomplished at modest cost using a CubeSat, a novel platform for space astrophysics missions. We will use a commercially available CubeSat bus and commercially available X-ray detectors to reduce development risk and minimize overall mission cost. HaloSat builds on the initiatives of GSFC/Wallops Flight Facility (WFF) in the development of CubeSats for low cost access to space and relies on the technical expertise of WFF personnel for spacecraft and mission design and operations. The team, from University of Iowa (UI), GSFC, Johns Hopkins, and CNRS (France), contains experts in X-ray detector development and data analysis and the astrophysics of hot plasmas and Galactic structure. The UI team will include a number of junior researchers (undergraduates, graduate students, and a postdoc) and help train them for future leadership roles on NASA space flight missions.

  9. X-38 Experimental Controls Laws

    NASA Technical Reports Server (NTRS)

    Munday, Steve; Estes, Jay; Bordano, Aldo J.

    2000-01-01

    X-38 Experimental Control Laws X-38 is a NASA JSC/DFRC experimental flight test program developing a series of prototypes for an International Space Station (ISS) Crew Return Vehicle, often called an ISS "lifeboat." X- 38 Vehicle 132 Free Flight 3, currently scheduled for the end of this month, will be the first flight test of a modem FCS architecture called Multi-Application Control-Honeywell (MACH), originally developed by the Honeywell Technology Center. MACH wraps classical P&I outer attitude loops around a modem dynamic inversion attitude rate loop. The dynamic inversion process requires that the flight computer have an onboard aircraft model of expected vehicle dynamics based upon the aerodynamic database. Dynamic inversion is computationally intensive, so some timing modifications were made to implement MACH on the slower flight computers of the subsonic test vehicles. In addition to linear stability margin analyses and high fidelity 6-DOF simulation, hardware-in-the-loop testing is used to verify the implementation of MACH and its robustness to aerodynamic and environmental uncertainties and disturbances.

  10. Impact of Vehicle Flexibility on IRVE-II Flight Dynamics

    NASA Technical Reports Server (NTRS)

    Bose, David M.; Toniolo, Matthew D.; Cheatwood, F. M.; Hughes, Stephen J.; Dillman, Robert A.

    2011-01-01

    The Inflatable Re-entry Vehicle Experiment II (IRVE-II) successfully launched from Wallops Flight Facility (WFF) on August 17, 2009. The primary objectives of this flight test were to demonstrate inflation and re-entry survivability, assess the thermal and drag performance of the reentry vehicle, and to collect flight data for refining pre-flight design and analysis tools. Post-flight analysis including trajectory reconstruction outlined in O Keefe3 demonstrated that the IRVE-II Research Vehicle (RV) met mission objectives but also identified a few anomalies of interest to flight dynamics engineers. Most notable of these anomalies was high normal acceleration during the re-entry pressure pulse. Deflection of the inflatable aeroshell during the pressure pulse was evident in flight video and identified as the likely cause of the anomaly. This paper provides a summary of further post-flight analysis with particular attention to the impact of aeroshell flexibility on flight dynamics and the reconciliation of flight performance with pre-flight models. Independent methods for estimating the magnitude of the deflection of the aeroshell experienced on IRVE-II are discussed. The use of the results to refine models for pre-flight prediction of vehicle performance is then described.

  11. High-Resolution Mesoscale Model Setup for the Eastern Range and Wallops Flight Facility

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.; Zavodsky, Bradley T.

    2015-01-01

    Mesoscale weather conditions can have an adverse effect on space launch, landing, ground processing, and weather advisories, watches, and warnings at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally-driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. These convective processes often last 60 minutes or less and pose a significant challenge to the local forecasters. Surface winds during the transition seasons (spring and fall) pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate mesoscale model forecasts are needed to better forecast a variety of unique weather phenomena. Global and national scale models cannot properly resolve important local-scale weather features at each location due to their horizontal resolutions being much too coarse. Therefore, a properly tuned local data assimilation (DA) and forecast model at a high resolution is needed to provide improved capability. To accomplish this, a number of sensitivity tests were performed using the Weather Research and Forecasting (WRF) model in order to determine the best DA/model configuration for operational use at each of the space launch ranges to best predict winds, precipitation, and temperature. A set of Perl scripts to run the Gridpoint Statistical Interpolation (GSI)/WRF in real-time were provided by NASA's Short-term Prediction Research and Transition Center (SPoRT). The GSI can analyze many types of observational data including satellite, radar, and conventional data. The GSI/WRF scripts use a cycled GSI system similar to the operational North American Mesoscale (NAM) model. The scripts run a 12-hour pre-cycle in which data are assimilated from 12 hours prior up to the model initialization time. A number of different model configurations were tested for both the ER and WFF by varying the horizontal resolution on which the data assimilation was done. Three different grid configurations were run for the ER and two configurations were run for WFF for archive cases from 27 Aug 2013 through 10 Nov 2013. To quantify model performance, standard model output will be compared to the Meteorological Assimilation Data Ingest System (MADIS) data. The MADIS observation data will be compared to the WRF forecasts using the Model Evaluation Tools (MET) verification package. In addition, the National Centers for Environmental Prediction's Stage IV precipitation data will be used to validate the WRF precipitation forecasts. The author will summarize the relative skill of the various WRF configurations and how each configuration behaves relative to the others, as well as determine the best model configuration for each space launch range.

  12. Range-Specific High-resolution Mesoscale Model Setup

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.

    2013-01-01

    This report summarizes the findings from an AMU task to determine the best model configuration for operational use at the ER and WFF to best predict winds, precipitation, and temperature. The AMU ran test cases in the warm and cool seasons at the ER and for the spring and fall seasons at WFF. For both the ER and WFF, the ARW core outperformed the NMM core. Results for the ER indicate that the Lin microphysical scheme and the YSU PBL scheme is the optimal model configuration for the ER. It consistently produced the best surface and upper air forecasts, while performing fairly well for the precipitation forecasts. Both the Ferrier and Lin microphysical schemes in combination with the YSU PBL scheme performed well for WFF in the spring and fall seasons. The AMU has been tasked with a follow-on modeling effort to recommended local DA and numerical forecast model design optimized for both the ER and WFF to support space launch activities. The AMU will determine the best software and type of assimilation to use, as well as determine the best grid resolution for the initialization based on spatial and temporal availability of data and the wall clock run-time of the initialization. The AMU will transition from the WRF EMS to NU-WRF, a NASA-specific version of the WRF that takes advantage of unique NASA software and datasets. 37

  13. GPS Remote Sensing Measurements Using Aerosonde UAV

    NASA Technical Reports Server (NTRS)

    Grant, Michael S.; Katzberg, Stephen J.; Lawrence, R. W.

    2005-01-01

    In February 2004, a NASA-Langley GPS Remote Sensor (GPSRS) unit was flown on an Aerosonde unmanned aerial vehicle (UAV) from the Wallops Flight Facility (WFF) in Virginia. Using direct and surface-reflected 1.575 GHz coarse acquisition (C/A) coded GPS signals, remote sensing measurements were obtained over land and portions of open water. The strength of the surface-reflected GPS signal is proportional to the amount of moisture in the surface, and is also influenced by surface roughness. Amplitude and other characteristics of the reflected signal allow an estimate of wind speed over open water. In this paper we provide a synopsis of the instrument accommodation requirements, installation procedures, and preliminary results from what is likely the first-ever flight of a GPS remote sensing instrument on a UAV. The correct operation of the GPSRS unit on this flight indicates that Aerosonde-like UAV's can serve as platforms for future GPS remote sensing science missions.

  14. The Wallops Flight Facility Rapid Response Range Operations Initiative

    NASA Technical Reports Server (NTRS)

    Underwood, Bruce E.; Kremer, Steven E.

    2004-01-01

    While the dominant focus on short response missions has appropriately centered on the launch vehicle and spacecraft, often overlooked or afterthought phases of these missions have been launch site operations and the activities of launch range organizations. Throughout the history of organized spaceflight, launch ranges have been the bane of flight programs as the source of expense, schedule delays, and seemingly endless requirements. Launch Ranges provide three basic functions: (1) provide an appropriate geographical location to meet orbital other mission trajectory requirements, (2) provide project services such as processing facilities, launch complexes, tracking and data services, and expendable products, and (3) assure safety and property protection to participating personnel and third-parties. The challenge with which launch site authorities continuously struggle, is the inherent conflict arising from projects whose singular concern is execution of their mission, and the range s need to support numerous simultaneous customers. So, while tasks carried out by a launch range committed to a single mission pale in comparison to efforts of a launch vehicle or spacecraft provider and could normally be carried out in a matter of weeks, major launch sites have dozens of active projects separate sponsoring organizations. Accommodating the numerous tasks associated with each mission, when hardware failures, weather, maintenance requirements, and other factors constantly conspire against the range resource schedulers, make the launch range as significant an impediment to responsive missions as launch vehicles and their cargo. The obvious solution to the launch site challenge was implemented years ago when the Department of Defense simply established dedicated infrastructure and personnel to dedicated missions, namely an Inter Continental Ballistic Missile. This however proves to be prohibitively expensive for all but the most urgent of applications. So the challenge becomes how can a launch site provide acceptably responsive mission services to a particular customer without dedicating extensive resources and while continuing to serve other projects? NASA's Wallops Flight Facility (WFF) is pursuing solutions to exactly this challenge. NASA, in partnership with the Virginia Commercial Space Flight Authority, has initiated the Rapid Response Range Operations Initiative (R3Ops). R3Ops is a multi-phased effort to incrementally establish and demonstrate increasingly responsive launch operations, with an ultimate goal of providing ELV-class services in a maximum of 7-10 days from initial notification routinely, and shorter schedules possible with committed resources. This target will be pursued within the reality of simultaneous concurrent programs, and ideally, largely independent of specialized flight system configurations. WFF has recently completed Phase 1 of R3Ops, an in-depth collection (through extensive expert interviews) and software modeling of individual steps by various range disciplines. This modeling is now being used to identify existing inefficiencies in current procedures, to identify bottlenecks, and show interdependencies. Existing practices are being tracked to provide a baseline to benchmark against as new procedures are implemented. This paper will describe in detail the philosophies behind WFF's R3Ops, the data collected and modeled in Phase 1, and strategies for meeting responsive launch requirements in a multi-user range environment planned for subsequent phases of this initiative.

  15. Modeling with Livingstone

    NASA Technical Reports Server (NTRS)

    Kurien, J.; Nayak, P.; Williams, B.; Koga, Dennis (Technical Monitor)

    1998-01-01

    MPL is the language with which a modeler describes a system to be diagnosed or controlled by Livingstone. MPL is used to specify what are the components of the system, how they are interconnected, and how they behave both nominally and when failed. Component behavioral models used by Livingstone are described by a set of propositional, well-formed formula (wff). An understanding of well-formed formula, primitive component types specified through defcomponent, and device structure specified by defmodule, is essential to understanding of MPL, This document describes: welI-formed formula (wff): The basis for describing the behavior of a component in a system defvalues: Specifies the domain (legal values) of a variable defcomponent: Defines the modes, behaviors and mode transitions for primitive components deftnodule: Defines composite devices, consisting of interconnected components defrelation: A macro mechanism for expanding a complex wff according to the value of an argument forall: An iteration construct used to expand a wff or relation on a set of arguments defsymbol-expansion: A mechanism for naming a collection of symbols (eg the name of all valves in the system)

  16. Range-Specific High-Resolution Mesoscale Model Setup: Data Assimilation

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.

    2014-01-01

    Mesoscale weather conditions can have an adverse effect on space launch, landing, and ground processing at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. Some of these other boundaries include the Indian River breeze front, Banana River breeze front, outflows from previous convection, horizontal convective rolls, convergence lines from other inland bodies of water such as Lake Okeechobee, the trailing convergence line from convergence of sea breeze fronts due to the shape of Cape Canaveral, frictional convergence lines from the islands in the Bahamas, convergence lines from soil moisture differences, convergence lines from cloud shading, and others. All these subtle weak boundary interactions often make forecasting of operationally important weather very difficult at KSC/CCAFS during the convective season (May-Oct). These convective processes often build quickly, last a short time (60 minutes or less), and occur over small distances, all of which also poses a significant challenge to the local forecasters who are responsible for issuing weather advisories, watches, and warnings. Surface winds during the transition seasons of spring and fall pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate mesoscale model forecasts are needed to aid in their decision making. Both the ER and WFF would benefit greatly from high-resolution mesoscale model output to better forecast a variety of unique weather phenomena. Global and national scale models cannot properly resolve important local-scale weather features at each location due to their horizontal resolutions being much too coarse. Therefore, a properly tuned model at a high resolution is needed to provide improved capability. This task is a multi-year effort in which the Applied Meteorology Unit (AMU) will tune the Weather Research and Forecasting (WRF) model individually for each range. The goal of the first year, the results of which are in this report, was to tune the WRF model based on the best model resolution and run time while using reasonable computing capabilities. To accomplish this, the ER and WFF supported the tasking of the AMU to perform a number of sensitivity tests in order to determine the best model configuration for operational use at each of the ranges to best predict winds, precipitation, and temperature (Watson 2013). This task is a continuation of that work and will provide a recommended local data assimilation (DA) and numerical forecast model design optimized for the ER and WFF to support space launch activities. The model will be optimized for local weather challenges at both ranges.

  17. The NASA Wallops Arc-Second Pointer (WASP) System for Precision Pointing of Scientific Balloon Instruments and Telescopes

    NASA Technical Reports Server (NTRS)

    Stuchlik, David W.; Lanzi, Raymond J.

    2017-01-01

    The National Aeronautics and Space Administrations (NASA) Wallops Flight Facility (WFF), part of the Goddard Space Flight Center (GSFC), has developed a unique pointing control system for instruments aboard scientific balloon gondolas. The ability to point large telescopes and instruments with arc-second accuracy and stability is highly desired by multiple scientific disciplines, such as Planetary, Earth Science, Heliospheric and Astrophysics, and the availability of a standardized system supplied by NASA alleviates the need for the science user to develop and provide their own system. In addition to the pointing control system, a star tracker has been developed with both daytime and nighttime capability to augment the WASP and provide an absolute pointing reference. The WASP Project has successfully completed five test flights and one operational science mission, and is currently supporting an additional test flight in 2017, along with three science missions with flights scheduled between 2018 and 2020. The WASP system has demonstrated precision pointing and high reliability, and is available to support scientific balloon missions.

  18. WFF TOPEX Software Documentation Altimeter Instrument File (AIF) Processing, October 1998. Volume 3

    NASA Technical Reports Server (NTRS)

    Lee, Jeffrey; Lockwood, Dennis

    2003-01-01

    This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Sensor Data Record (SDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

  19. DAQ: Software Architecture for Data Acquisition in Sounding Rockets

    NASA Technical Reports Server (NTRS)

    Ahmad, Mohammad; Tran, Thanh; Nichols, Heidi; Bowles-Martinez, Jessica N.

    2011-01-01

    A multithreaded software application was developed by Jet Propulsion Lab (JPL) to collect a set of correlated imagery, Inertial Measurement Unit (IMU) and GPS data for a Wallops Flight Facility (WFF) sounding rocket flight. The data set will be used to advance Terrain Relative Navigation (TRN) technology algorithms being researched at JPL. This paper describes the software architecture and the tests used to meet the timing and data rate requirements for the software used to collect the dataset. Also discussed are the challenges of using commercial off the shelf (COTS) flight hardware and open source software. This includes multiple Camera Link (C-link) based cameras, a Pentium-M based computer, and Linux Fedora 11 operating system. Additionally, the paper talks about the history of the software architecture's usage in other JPL projects and its applicability for future missions, such as cubesats, UAVs, and research planes/balloons. Also talked about will be the human aspect of project especially JPL's Phaeton program and the results of the launch.

  20. Reengineering legacy software to object-oriented systems

    NASA Technical Reports Server (NTRS)

    Pitman, C.; Braley, D.; Fridge, E.; Plumb, A.; Izygon, M.; Mears, B.

    1994-01-01

    NASA has a legacy of complex software systems that are becoming increasingly expensive to maintain. Reengineering is one approach to modemizing these systems. Object-oriented technology, other modem software engineering principles, and automated tools can be used to reengineer the systems and will help to keep maintenance costs of the modemized systems down. The Software Technology Branch at the NASA/Johnson Space Center has been developing and testing reengineering methods and tools for several years. The Software Technology Branch is currently providing training and consulting support to several large reengineering projects at JSC, including the Reusable Objects Software Environment (ROSE) project, which is reengineering the flight analysis and design system (over 2 million lines of FORTRAN code) into object-oriented C++. Many important lessons have been learned during the past years; one of these is that the design must never be allowed to diverge from the code during maintenance and enhancement. Future work on open, integrated environments to support reengineering is being actively planned.

  1. Overview of the Nasa/science Mission Directorate University Student Instrument Project (usip)

    NASA Astrophysics Data System (ADS)

    Pierce, D. L.

    2016-12-01

    These are incredible times of space and Earth science discovery related to the Earth system, our Sun, the planets, and the universe. The National Aeronautics and Space Administration (NASA) Science Mission Directorate (SMD) provides authentic student-led hands-on flight research projects as a component part of the NASA's science program. The goal of the Undergraduate Student Instrument Project (USIP) is to enable student-led scientific and technology investigations, while also providing crucial hands-on training opportunities for the Nation's future researchers. SMD, working with NASA's Office of Education (OE), the Space Technology Mission Directorate (STMD) and its Centers (GSFC/WFF and AFRC), is actively advancing the vision for student flight research using NASA's suborbital and small spacecraft platforms. Recently proposed and selected USIP projects will open up opportunities for undergraduate researchers in conducting science and developing space technologies. The paper will present an overview of USIP, results of USIP-I, and the status of current USIP-II projects that NASA is sponsoring and expects to fly in the near future.

  2. Flight demonstration of flight termination system and solid rocket motor ignition using semiconductor laser initiated ordnance

    NASA Astrophysics Data System (ADS)

    Schulze, Norman R.; Maxfield, B.; Boucher, C.

    1995-01-01

    Solid State Laser Initiated Ordnance (LIO) offers new technology having potential for enhanced safety, reduced costs, and improved operational efficiency. Concerns over the absence of programmatic applications of the technology, which has prevented acceptance by flight programs, should be abated since LIO has now been operationally implemented by the Laser Initiated Ordnance Sounding Rocket Demonstration (LOSRD) Program. The first launch of solid state laser diode LIO at the NASA Wallops Flight Facility (WFF) occurred on March 15, 1995 with all mission objectives accomplished. This project, Phase 3 of a series of three NASA Headquarters LIO demonstration initiatives, accomplished its objective by the flight of a dedicated, all-LIO sounding rocket mission using a two-stage Nike-Orion launch vehicle. LIO flight hardware, made by The Ensign-Bickford Company under NASA's first Cooperative Agreement with Profit Making Organizations, safely initiated three demanding pyrotechnic sequence events, namely, solid rocket motor ignition from the ground and in flight, and flight termination, i.e., as a Flight Termination System (FTS). A flight LIO system was designed, built, tested, and flown to support the objectives of quickly and inexpensively putting LIO through ground and flight operational paces. The hardware was fully qualified for this mission, including component testing as well as a full-scale system test. The launch accomplished all mission objectives in less than 11 months from proposal receipt. This paper concentrates on accomplishments of the ordnance aspects of the program and on the program's implementation and results. While this program does not generically qualify LIO for all applications, it demonstrated the safety, technical, and operational feasibility of those two most demanding applications, using an all solid state safe and arm system in critical flight applications.

  3. Configurable Multi-Purpose Processor

    NASA Technical Reports Server (NTRS)

    Valencia, J. Emilio; Forney, Chirstopher; Morrison, Robert; Birr, Richard

    2010-01-01

    Advancements in technology have allowed the miniaturization of systems used in aerospace vehicles. This technology is driven by the need for next-generation systems that provide reliable, responsive, and cost-effective range operations while providing increased capabilities such as simultaneous mission support, increased launch trajectories, improved launch, and landing opportunities, etc. Leveraging the newest technologies, the command and telemetry processor (CTP) concept provides for a compact, flexible, and integrated solution for flight command and telemetry systems and range systems. The CTP is a relatively small circuit board that serves as a processing platform for high dynamic, high vibration environments. The CTP can be reconfigured and reprogrammed, allowing it to be adapted for many different applications. The design is centered around a configurable field-programmable gate array (FPGA) device that contains numerous logic cells that can be used to implement traditional integrated circuits. The FPGA contains two PowerPC processors running the Vx-Works real-time operating system and are used to execute software programs specific to each application. The CTP was designed and developed specifically to provide telemetry functions; namely, the command processing, telemetry processing, and GPS metric tracking of a flight vehicle. However, it can be used as a general-purpose processor board to perform numerous functions implemented in either hardware or software using the FPGA s processors and/or logic cells. Functionally, the CTP was designed for range safety applications where it would ultimately become part of a vehicle s flight termination system. Consequently, the major functions of the CTP are to perform the forward link command processing, GPS metric tracking, return link telemetry data processing, error detection and correction, data encryption/ decryption, and initiate flight termination action commands. Also, the CTP had to be designed to survive and operate in a launch environment. Additionally, the CTP was designed to interface with the WFF (Wallops Flight Facility) custom-designed transceiver board which is used in the Low Cost TDRSS Transceiver (LCT2) also developed by WFF. The LCT2 s transceiver board demodulates commands received from the ground via the forward link and sends them to the CTP, where they are processed. The CTP inputs and processes data from the inertial measurement unit (IMU) and the GPS receiver board, generates status data, and then sends the data to the transceiver board where it is modulated and sent to the ground via the return link. Overall, the CTP has combined processing with the ability to interface to a GPS receiver, an IMU, and a pulse code modulation (PCM) communication link, while providing the capability to support common interfaces including Ethernet and serial interfaces boarding a relatively small-sized, lightweight package.

  4. GPS Metric Tracking Unit

    NASA Technical Reports Server (NTRS)

    2008-01-01

    As Global Positioning Satellite (GPS) applications become more prevalent for land- and air-based vehicles, GPS applications for space vehicles will also increase. The Applied Technology Directorate of Kennedy Space Center (KSC) has developed a lightweight, low-cost GPS Metric Tracking Unit (GMTU), the first of two steps in developing a lightweight, low-cost Space-Based Tracking and Command Subsystem (STACS) designed to meet Range Safety's link margin and latency requirements for vehicle command and telemetry data. The goals of STACS are to improve Range Safety operations and expand tracking capabilities for space vehicles. STACS will track the vehicle, receive commands, and send telemetry data through the space-based asset, which will dramatically reduce dependence on ground-based assets. The other step was the Low-Cost Tracking and Data Relay Satellite System (TDRSS) Transceiver (LCT2), developed by the Wallops Flight Facility (WFF), which allows the vehicle to communicate with a geosynchronous relay satellite. Although the GMTU and LCT2 were independently implemented and tested, the design collaboration of KSC and WFF engineers allowed GMTU and LCT2 to be integrated into one enclosure, leading to the final STACS. In operation, GMTU needs only a radio frequency (RF) input from a GPS antenna and outputs position and velocity data to the vehicle through a serial or pulse code modulation (PCM) interface. GMTU includes one commercial GPS receiver board and a custom board, the Command and Telemetry Processor (CTP) developed by KSC. The CTP design is based on a field-programmable gate array (FPGA) with embedded processors to support GPS functions.

  5. The 2014 Annual(MCWG)Annual Metrology and Calibration Working Gr

    NASA Image and Video Library

    2014-05-07

    Annual Metrology and Calibration Working Group Face to Face meeting held at Langley Research Center; Front Row (L to R): Stacy Sigmon – LaRC, Brent Watling – JSC, Ralph Hickman – WFF, Kirk Foster – MSFC, Don Wilson – SSC, Greg Boyd – JSC, Perry King – KSC, Bobby Price – GSFC, Felicia Donnell – GSFC, Perry LaRosa – GRC. Second Row (L to R): Ken Mathews – KSC, Darrell Shoup – WSTF, Gary Kennedy – MSFC, Terry Fleet – GRC, Damon Flansburg – ARC, Salvatore Tomaselli - WFF, Bruce Farner - SSC, David Scott – JPL, Jim Wachter – KSC, Shawn Britton – LaRC.

  6. Development of U.S. Government General Technical Requirements for UAS Flight Safety Systems Utilizing the Iridium Satellite Constellation

    NASA Technical Reports Server (NTRS)

    Murray, Jennifer; Birr, Richard

    2010-01-01

    This slide presentation reviews the development of technical requirements for Unmanned Aircraft Systems (UAS) utilization of the Iridium Satellite Constellation to provide flight safety. The Federal Aviation Authority (FAA) required an over-the-horizon communication standard to guarantee flight safety before permitting widespread UAS flights in the National Air Space (NAS). This is important to ensure reliable control of UASs during loss-link and over-the-horizon scenarios. The core requirement was to utilize a satellite system to send GPS tracking data and other telemetry from a flight vehicle down to the ground. Iridium was chosen as the system because it is one of the only true satellite systems that has world wide coverage, and the service has a highly reliable link margin. The Iridium system, the flight modems, and the test flight are described.

  7. BOREAS RSS-20 POLDER C-130 Measurements of Surface BRDF

    NASA Technical Reports Server (NTRS)

    Leroy, Marc; Hall, Forrest G. (Editor); Nickerson, Jaime (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    This Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-20 data set contains measurements of surface bidirectional reflectance distribution function (BRDF) made by the polarization and Directionality of Earth reflectances (POLDER) instrument over several surface types (pine, spruce, fen) of the BOREAS southern study area (SSA) during the 1994 intensive field campaigns (IFCs). Single-point BRDF values were acquired either from the NASA Ames Research Center (ARC) C-130 aircraft or from a NASA Wallops Flight Facility (WFF) helicopter. A related data set collected from the helicopter platform is available as is POLDER imagery acquired from the C-130. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  8. Performance Evaluation of Data Modems for the Aeronautical Satellite Channel.

    DOT National Transportation Integrated Search

    1975-09-01

    Several modems and satellite subsystems were tested with the aid of an aeronautical channel simulation facility. The modems tested included a high performance DPSK modem, a high performance CPSK modem, two hybird voice/data modems, and a lower perfor...

  9. Compilation and development of K-6 aerospace materials for implementation in NASA spacelink electronic information system

    NASA Technical Reports Server (NTRS)

    Blake, Jean A.

    1987-01-01

    Spacelink is an electronic information service to be operated by the Marshall Space Flight Center. It will provide NASA news and educational resources including software programs that can be accessed by anyone with a computer and modem. Spacelink is currently being installed and will soon begin service. It will provide daily updates of NASA programs, information about NASA educational services, manned space flight, unmanned space flight, aeronautics, NASA itself, lesson plans and activities, and space program spinoffs. Lesson plans and activities were extracted from existing NASA publications on aerospace activities for the elementary school. These materials were arranged into 206 documents which have been entered into the Spacelink program for use in grades K-6.

  10. GPS Sounding Rocket Developments

    NASA Technical Reports Server (NTRS)

    Bull, Barton

    1999-01-01

    Sounding rockets are suborbital launch vehicles capable of carrying scientific payloads several hundred miles in altitude. These missions return a variety of scientific data including; chemical makeup and physical processes taking place In the atmosphere, natural radiation surrounding the Earth, data on the Sun, stars, galaxies and many other phenomena. In addition, sounding rockets provide a reasonably economical means of conducting engineering tests for instruments and devices used on satellites and other spacecraft prior to their use in more expensive activities. The NASA Sounding Rocket Program is managed by personnel from Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia. Typically around thirty of these rockets are launched each year, either from established ranges at Wallops Island, Virginia, Poker Flat Research Range, Alaska; White Sands Missile Range, New Mexico or from Canada, Norway and Sweden. Many times launches are conducted from temporary launch ranges in remote parts of the world requi6ng considerable expense to transport and operate tracking radars. An inverse differential GPS system has been developed for Sounding Rocket. This paper addresses the NASA Wallops Island history of GPS Sounding Rocket experience since 1994 and the development of a high accurate and useful system.

  11. Early Operations Flight Correlation of the Lunar Laser Communications Demonstration (LLCD) on the Lunar Atmosphere and Dust Environment Explorer (LADEE)

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Yang, Kan; Nguyen, Daniel; Cornwell, Donald

    2015-01-01

    The Lunar Atmosphere and Dust Environment Explorer (LADEE) mission launched on September 7, 2013 with a one month cruise before lunar insertion. The LADEE spacecraft is a power limited, octagonal, composite bus structure with solar panels on all eight sides with four vertical segments per side and 2 panels dedicated to instruments. One of these panels has the Lunar Laser Communications Demonstration (LLCD), which represents a furthering of the laser communications technology demonstration proved out by the Lunar Reconnaissance Orbiter (LRO). LLCD increases the bandwidth of communication to and from the moon with less mass and power than LROs technology demonstrator. The LLCD Modem and Controller boxes are mounted to an internal cruciform composite panel and have no dedicated radiator. The thermal design relies on power cycling of the boxes and radiation of waste heat to the inside of the panels, which then reject the heat when facing cold space. The LADEE mission includes a slow roll and numerous attitudes to accommodate the challenging thermal requirements for all the instruments on board. During the cruise phase, the internal Modem and Controller avionics for LLCD were warmer than predicted by more than modeling uncertainty would suggest. This caused concern that if the boxes were considerably warmer than expected while off, they would also be warmer when operating and could limit the operational time when in lunar orbit. The thermal group at Goddard Space Flight Center evaluated the models and design for these critical avionics for LLCD. Upon receipt of the spacecraft models and audit was performed and data was collected from the flight telemetry to perform a sanity check of the models and to correlate to flight where possible. This paper describes the efforts to correlate the model to flight data and to predict the thermal performance when in lunar orbit and presents some lessons learned.

  12. SU-G-TeP1-03: Beam Quality Correction Factors for Linear Accelerator with and Without Flattening Filter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Czarnecki, D; Voigts-Rhetz, P von; Zink, K

    2016-06-15

    Purpose: The impact of removing the flattening filter on absolute dosimetry based on IAEA’s TPR-398 and AAPM’s TG-51 was investigated in this study using Monte Carlo simulations. Methods: The EGSnrc software package was used for all Monte Carlo simulations performed in this work. Five different ionization chambers and nine linear accelerator heads have been modeled according to technical drawings. To generate a flattening filter free radiation field the flattening filter was replaced by a 2 mm thick aluminum layer. Dose calculation in a water phantom were performed to calculate the beam quality correction factor k{sub Q} as a function ofmore » the beam quality specifiers %dd(10){sub x}, TPR{sub 20,10} and mean photon and electron energies at the point of measurement in photon fields with (WFF) and without flattening filter (FFF). Results: The beam quality correction factor as a function of %dd(10){sub x} differs systematically between FFF and WFF beams for all investigated ionization chambers. The largest difference of 1.8% was observed for the largest investigated Farmer-type ionization chamber with a sensitive volume of 0.69 cm{sup 3}. For ionization chambers with a smaller nominal sensitive volume (0.015 – 0.3 cm{sup 3}) the deviation was less than 0.4% between WFF and FFF beams for %dd(10){sub x} > 62%. The specifier TPR{sub 20,10} revealed only a good correlation between WFF and FFF beams (< 0.3%) for low energies. Conclusion: The results confirm that %dd(10){sub x} is a suitable beam quality specifier for FFF beams with an acceptable bias. The deviation depends on the volume of the ionization chamber. Using %dd(10){sub x} to predict k{sub Q} for a large volume chamber in a FFF photon field may lead to not acceptable errors according to the results of this study. This bias may be caused by the volume effect due to the inhomogeneous photon fields of FFF linear accelerators.« less

  13. An integrated user-oriented laboratory for verification of digital flight control systems: Features and capabilities

    NASA Technical Reports Server (NTRS)

    Defeo, P.; Doane, D.; Saito, J.

    1982-01-01

    A Digital Flight Control Systems Verification Laboratory (DFCSVL) has been established at NASA Ames Research Center. This report describes the major elements of the laboratory, the research activities that can be supported in the area of verification and validation of digital flight control systems (DFCS), and the operating scenarios within which these activities can be carried out. The DFCSVL consists of a palletized dual-dual flight-control system linked to a dedicated PDP-11/60 processor. Major software support programs are hosted in a remotely located UNIVAC 1100 accessible from the PDP-11/60 through a modem link. Important features of the DFCSVL include extensive hardware and software fault insertion capabilities, a real-time closed loop environment to exercise the DFCS, an integrated set of software verification tools, and a user-oriented interface to all the resources and capabilities.

  14. NASA Langley's AirSTAR Testbed: A Subscale Flight Test Capability for Flight Dynamics and Control System Experiments

    NASA Technical Reports Server (NTRS)

    Jordan, Thomas L.; Bailey, Roger M.

    2008-01-01

    As part of the Airborne Subscale Transport Aircraft Research (AirSTAR) project, NASA Langley Research Center (LaRC) has developed a subscaled flying testbed in order to conduct research experiments in support of the goals of NASA s Aviation Safety Program. This research capability consists of three distinct components. The first of these is the research aircraft, of which there are several in the AirSTAR stable. These aircraft range from a dynamically-scaled, twin turbine vehicle to a propeller driven, off-the-shelf airframe. Each of these airframes carves out its own niche in the research test program. All of the airplanes have sophisticated on-board data acquisition and actuation systems, recording, telemetering, processing, and/or receiving data from research control systems. The second piece of the testbed is the ground facilities, which encompass the hardware and software infrastructure necessary to provide comprehensive support services for conducting flight research using the subscale aircraft, including: subsystem development, integrated testing, remote piloting of the subscale aircraft, telemetry processing, experimental flight control law implementation and evaluation, flight simulation, data recording/archiving, and communications. The ground facilities are comprised of two major components: (1) The Base Research Station (BRS), a LaRC laboratory facility for system development, testing and data analysis, and (2) The Mobile Operations Station (MOS), a self-contained, motorized vehicle serving as a mobile research command/operations center, functionally equivalent to the BRS, capable of deployment to remote sites for supporting flight tests. The third piece of the testbed is the test facility itself. Research flights carried out by the AirSTAR team are conducted at NASA Wallops Flight Facility (WFF) on the Eastern Shore of Virginia. The UAV Island runway is a 50 x 1500 paved runway that lies within restricted airspace at Wallops Flight Facility. The facility provides all the necessary infrastructure to conduct the research flights in a safe and efficient manner. This paper gives a comprehensive overview of the development of the AirSTAR testbed.

  15. Three-Centimeter Doppler Radar Observations of Wingtip-Generated Wake Vortices in Clear Air

    NASA Technical Reports Server (NTRS)

    Marshall, Robert E.; Mudukutore, Ashok; Wissel, Vicki L. H.; Myers, Theodore

    1997-01-01

    This report documents a high risk, high pay-off experiment with the objective of detecting, for the first time, the presence of aircraft wake vortices in clear air using X-band Doppler radar. Field experiments were conducted in January 1995 at the Wallops Flight Facility (WFF) to demonstrate the capability of the 9.33 GHz (I=3 cm) radar, which was assembled using an existing nine-meter parabolic antenna reflector at VVTT and the receiver/transmitter from the NASA Airborne Windshear Radar-Program. A C-130-aircraft, equipped with wingtip smoke generators, created visually marked wake vortices, which were recorded by video cameras. A C-band radar also observed the wake vortices during detection attempts with the X-band radar. Rawinsonde data was used to calculate vertical soundings of wake vortex decay time, cross aircraft bearing wind speed, and water vapor mixing ratio for aircraft passes over the radar measurement range. This experiment was a pathfinder in predicting, in real time, the location and persistence of C-130 vortices, and in setting the flight path of the aircraft to optimize X-band radar measurement of the wake vortex core in real time. This experiment was conducted in support of the NASA Aircraft Vortex Spacing System (AVOSS).

  16. Airborne Laser Altimetric Monitoring of the Rapid Evolution of Topography in the Long Valley, CA, Caldera

    NASA Technical Reports Server (NTRS)

    Rundle, John

    1998-01-01

    A consortium of investigators from several universities and Government agencies have conducted a series of aircraft topographic surveys over the Long Valley caldera, California. The region has a geologic history of extensive volcanism, and its central dome has recently been undergoing resurgent uplift episodes of up to 4 cm per year, a deformation rate that is still continuing. These surveys were conducted from the NASA WFF T39 jet aircraft, outfitted with a nadir-profiling altimetric laser (ATLAS), a GPS guidance system for in-flight precision navigation, two P-code GPS receivers, a Litton LTN92 inertial unit for attitude determination, and both video and still-frame aerial cameras. In addition, two base-station GPS receivers were deployed for post-flight differential navigation, complementing the permanent GPS station operated on the resurgent dome by JPL, and a kinematic automobile survey of roads crossing the area was conducted, thereby complementing the JPL kinematic GPS surveys of some of the same roads. Precision flying yielded multiple profiles along nearly identical paths, including crossing profiles over selected locations within the caidera and calibration flights over Mono Lake, and Lake Crowley. Data from the most recent survey in 1995 are at this time still being reduced, but the standard error of the mean is very low (< 3 mm), due to the high number of crossover points. We thus intend to evaluate the technique for measuring systematic changes in the dome height over time.

  17. Results of AEROSAT channel simulation tests Q-M/PSK voice/data modem, TSC ranging modem

    DOT National Transportation Integrated Search

    1976-07-01

    Two modems which are candidates for the Aeronautical Satellite (AEROSAT : Test and Evaluation Program have been tested by the Transportation : Systems Center channel simulation facility. One was a hybrid modem : which can simultaneously transmit and ...

  18. Refining, revising, augmenting, compiling and developing computer assisted instruction K-12 aerospace materials for implementation in NASA spacelink electronic information system

    NASA Technical Reports Server (NTRS)

    Blake, Jean A.

    1988-01-01

    The NASA Spacelink is an electronic information service operated by the Marshall Space Flight Center. The Spacelink contains extensive NASA news and educational resources that can be accessed by a computer and modem. Updates and information are provided on: current NASA news; aeronautics; space exploration: before the Shuttle; space exploration: the Shuttle and beyond; NASA installations; NASA educational services; materials for classroom use; and space program spinoffs.

  19. Electronics design of a multi-rate DPSK modem for free-space optical communications

    NASA Astrophysics Data System (ADS)

    Rao, H. G.; Browne, C. A.; Caplan, D. O.; Carney, J. J.; Chavez, M. L.; Fletcher, A. S.; Fitzgerald, J. J.; Kaminsky, R. D.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Mikulina, O. V.; Murphy, R. J.; Seaver, M. M.; Scheinbart, M. S.; Spellmeyer, N. W.; Wang, J. P.

    2014-03-01

    We have designed and experimentally demonstrated a radiation-hardened modem suitable for NASA's Laser Communications Relay Demonstration. The modem supports free-space DPSK communication over a wide range of channel rates, from 72 Mb/s up to 2.88 Gb/s. The modem transmitter electronics generate a bursty DPSK waveform, such that only one optical modulator is required. The receiver clock recovery is capable of operating over all channel rates at average optical signal levels below -70 dBm. The modem incorporates a radiation-hardened Xilinx Virtex 5 FPGA and a radiation-hardened Aeroflex UT699 CPU. The design leverages unique capabilities of each device, such as the FPGA's multi-gigabit transceivers. The modem scrubs itself against radiation events, but does not require pervasive triple-mode redundant logic. The modem electronics include automatic stabilization functions for its optical components, and software to control its initialization and operation. The design allows the modem to be put into a low-power standby mode.

  20. Aeroservoelastic Modeling and Validation of a Thrust-Vectoring F/A-18 Aircraft

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.

    1996-01-01

    An F/A-18 aircraft was modified to perform flight research at high angles of attack (AOA) using thrust vectoring and advanced control law concepts for agility and performance enhancement and to provide a testbed for the computational fluid dynamics community. Aeroservoelastic (ASE) characteristics had changed considerably from the baseline F/A-18 aircraft because of structural and flight control system amendments, so analyses and flight tests were performed to verify structural stability at high AOA. Detailed actuator models that consider the physical, electrical, and mechanical elements of actuation and its installation on the airframe were employed in the analysis to accurately model the coupled dynamics of the airframe, actuators, and control surfaces. This report describes the ASE modeling procedure, ground test validation, flight test clearance, and test data analysis for the reconfigured F/A-18 aircraft. Multivariable ASE stability margins are calculated from flight data and compared to analytical margins. Because this thrust-vectoring configuration uses exhaust vanes to vector the thrust, the modeling issues are nearly identical for modem multi-axis nozzle configurations. This report correlates analysis results with flight test data and makes observations concerning the application of the linear predictions to thrust-vectoring and high-AOA flight.

  1. Distributed Sensor Networks

    DTIC Science & Technology

    1980-09-30

    the main Laboratory is provided by 9600-baud short-haul modems with unloaded lines. A new version of the real-time kernel (DAK) has been developed. It...and control computer have been in- vestigated, modems have been procured, and an initial 4-wire line with 9.6 kbits modem has been installed between the...telephone system or leased (unloaded) 4-wire private-line metallic circuits. To this end, two pairs of short-haul modems and a pair of long-haul modems have

  2. Materiel Readiness Support Activity Automation Plan

    DTIC Science & Technology

    1986-09-01

    Hardwire leased lines Sytek RF broadband cable modems Digital phone switched service Medium Speed - up to 56k baud RF modems Digital phone service High...dialing 121 I iI Medium Speed - up to 56k baud RF modems - up to 56k baud sync modem $2070 plus installation - $25 per month maintenance - $1200 per...security is to disconnect net- work, modem , and hardwire access (that is, all external access to the machine) after 5 p.m. (normal business hours

  3. Flight Control Development for the ARH-70 Armed Reconnaissance Helicopter Program

    NASA Technical Reports Server (NTRS)

    Christensen, Kevin T.; Campbell, Kip G.; Griffith, Carl D.; Ivler, Christina M.; Tischler, Mark B.; Harding, Jeffrey W.

    2008-01-01

    In July 2005, Bell Helicopter won the U.S. Army's Armed Reconnaissance Helicopter competition to produce a replacement for the OH-58 Kiowa Warrior capable of performing the armed reconnaissance mission. To meet the U.S. Army requirement that the ARH-70A have Level 1 handling qualities for the scout rotorcraft mission task elements defined by ADS-33E-PRF, Bell equipped the aircraft with their generic automatic flight control system (AFCS). Under the constraints of the tight ARH-70A schedule, the development team used modem parameter identification and control law optimization techniques to optimize the AFCS gains to simultaneously meet multiple handling qualities design criteria. This paper will show how linear modeling, control law optimization, and simulation have been used to produce a Level 1 scout rotorcraft for the U.S. Army, while minimizing the amount of flight testing required for AFCS development and handling qualities evaluation of the ARH-70A.

  4. Workstation-Based Simulation for Rapid Prototyping and Piloted Evaluation of Control System Designs

    NASA Technical Reports Server (NTRS)

    Mansur, M. Hossein; Colbourne, Jason D.; Chang, Yu-Kuang; Aiken, Edwin W. (Technical Monitor)

    1998-01-01

    The development and optimization of flight control systems for modem fixed- and rotary-. wing aircraft consume a significant portion of the overall time and cost of aircraft development. Substantial savings can be achieved if the time required to develop and flight test the control system, and the cost, is reduced. To bring about such reductions, software tools such as Matlab/Simulink are being used to readily implement block diagrams and rapidly evaluate the expected responses of the completed system. Moreover, tools such as CONDUIT (CONtrol Designer's Unified InTerface) have been developed that enable the controls engineers to optimize their control laws and ensure that all the relevant quantitative criteria are satisfied, all within a fully interactive, user friendly, unified software environment.

  5. Remote Synchronization Experiments for Future Quasi-Zenith Satellite System Using Current Geostationary Satellites

    DTIC Science & Technology

    2008-12-01

    Timekeeping,” Application Note 1289 (Hewlett-Packard), p. 60. [5] F. Tappero, A. Dempster, T . Iwata, M. Imae, T . Ikegami , Y. Fukuyama, K. Hagimoto, and A...the timing controller are also received. Modem ( T ): The Modem ( T ) is one of the three TWSTFT modems used in the experiments (“ T ” stands for...PN signal. In the experiments, the modem ( T ) was referenced to the time signal of the TTA and the RESSOX control signal was transmitted to the modem

  6. Experimentation and Evaluation of Advanced Integrated System Concepts.

    DTIC Science & Technology

    1980-09-26

    ART). (b) Selects one of four trunk circuits from each trunk (m) Dual Modem and Loop Interface (DMLI) card. circuit card. (n) Dictation and paging...Arbitrator L Bus - Modems ET _Modems Modems Figure 4-1 Certain Telenet Processor models (see Section 4.3 for details) can be equipped with redundancy to...JMemory Bank B Memory Bank A ArbittrAto Arbitrator A t a i Interface U a Modems $ Figure 4-2 In a system with common logic redundancy all centrally

  7. Digital 8-DPSK Modem For Trellis-Coded Communication

    NASA Technical Reports Server (NTRS)

    Jedrey, T. C.; Lay, N. E.; Rafferty, W.

    1989-01-01

    Digital real-time modem processes octuple differential-phase-shift-keyed trellis-coded modulation. Intended for use in communicating data at rate up to 4.8 kb/s in land-mobile satellite channel (Rician fading) of 5-kHz bandwidth at carrier frequency of 1 to 2 GHz. Modulator and demodulator contain digital signal processors performing modem functions. Design flexible in that functions altered via software. Modem successfully tested and evaluated in both laboratory and field experiments, including recent full-scale satellite experiment. In all cases, modem performed within 1 dB of theory. Other communication systems benefitting from this type of modem include land mobile (without satellites), paging, digitized voice, and frequency-modulation subcarrier data broadcasting.

  8. Modems for emerging digital cellular-mobile radio system

    NASA Technical Reports Server (NTRS)

    Feher, Kamilo

    1991-01-01

    Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

  9. Applied Meteorology Unit (AMU) Quarterly Report Fourth Quarter FY-13

    NASA Technical Reports Server (NTRS)

    Bauman, William; Crawford, Winifred; Watson, Leela; Shafer, Jaclyn; Huddleston, Lisa

    2013-01-01

    Ms. Shafer completed the task to determine relationships between pressure gradients and peak winds at Vandenberg Air Force Base (VAFB), and began developing a climatology for the VAFB wind towers; Dr. Huddleston completed the task to develop a tool to help forecast the time of the first lightning strike of the day in the Kennedy Space Center (KSC)/Cape Canaveral Air Force Station (CCAFS) area; Dr. Bauman completed work on a severe weather forecast tool focused on the Eastern Range (ER), and also developed upper-winds analysis tools for VAFB and Wallops Fl ight Facility (WFF); Ms. Crawford processed and displayed radar data in the software she will use to create a dual-Doppler analysis over the east-central Florida and KSC/CCAFS areas; Mr. Decker completed developing a wind pairs database for the Launch Services Program to use when evaluating upper-level winds for launch vehicles; Dr. Watson continued work to assimilate observational data into the high-resolution model configurations she created for WFF and the ER.

  10. Analog Building Blocks for Communications Modems.

    DTIC Science & Technology

    1977-01-01

    x*—*- A0-A039 82b ELECTRONIC COMMUNICATIONS INC ST PETERSBURG FLA F/6 9/5 ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS .(U) JAN 77 B BLACK...F33615-7<t-C-1120 UNCLASSIFIED AFAL-TR-76-29 NL ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS ELECTRONIC COMMUNICATIONS INC. A SUBSIDIARY OF...Idantltr Or Mac* numb*,; Avionics Building-Block modules Frequency Synthesize* Costas Demodulator Amplifier Modem Frequency Multiplier ’ -^ « TRACT

  11. System Design Plan for a DCS (Defense Communications System) Data Transmission Network.

    DTIC Science & Technology

    1981-07-01

    modems , FDO group modems , and Voice Frequency Carrier Telegraph (VFCT) networks. The DTN will be a synchronous network and its implementation must coincide...Frequency (VF) modems and Voice Frequency Carrier Telegraph (VFCT) networks. Further, data circuits can be extended over present analog FDM facilities using...VF or group data modems . In addition to the availability of terrestrial and satellite digital transmission facilities, the implementation of the DTN

  12. Cable Modems' Transmitted RF: A Study of SNR, Error Rates, Transmit Levels, and Trouble Call Metrics

    ERIC Educational Resources Information Center

    Tebbetts, Jo A.

    2013-01-01

    Hypotheses were developed and tested to measure the cable modems operational metrics response to a reconfiguration of the cable modems' transmitted RF applied to the CMTS. The purpose of this experiment was to compare two groups on the use of non-federal RF spectrum to determine if configuring the cable modems' transmitted RF from 25.2…

  13. Defense Healthcare Information Assurance Program

    DTIC Science & Technology

    1999-11-01

    56k Modem • Cisco 1OS 12.0 operation at the MTFs, the Team • Cisco 3640 Router Configuration Fileo 24- 56k Modems recommended the Cisco 3600 series...temporarily substituted by the vendor pending availability of ordered components (e.g., the modem circuit board for the router). " Each site created a...control for software / hardware modifications and upgrades? 3.5 Is there a process for introducing new equipment (such as hosts, printers, or modems

  14. Performance of Trellis Coded 256 QAM super-multicarrier modem VLSI's for SDH interface outage-free digital microwave radio

    NASA Astrophysics Data System (ADS)

    Aikawa, Satoru; Nakamura, Yasuhisa; Takanashi, Hitoshi

    1994-02-01

    This paper describes the performance of an outage free SXH (Synchronous Digital Hierarchy) interface 256 QAM modem. An outage free DMR (Digital Microwave Radio) is achieved by a high coding gain trellis coded SPORT QAM and Super Multicarrier modem. A new frame format and its associated circuits connect the outage free modem to the SDH interface. The newly designed VLSI's are key devices for developing the modem. As an overall modem performance, BER (bit error rate) characteristics and equipment signatures are presented. A coding gain of 4.7 dB (at a BER of 10(exp -4)) is obtained using SPORT 256 QAM and Viterbi decoding. This coding gain is realized by trellis coding as well as by increasing of transmission rate. Roll-off factor is decreased to maintain the same frequency occupation and modulation level as ordinary SDH 256 QAM modern.

  15. FEC combined burst-modem for business satellite communications use

    NASA Astrophysics Data System (ADS)

    Murakami, K.; Miyake, M.; Fuji, T.; Moritani, Y.; Fujino, T.

    The authors recently developed two types of FEC (forward error correction) combined modems both applicable to low-data-rate and intermediate-data-rate TDMA international satellite communications. Each FEC combined modem consists of a QPSK (quadrature phase-shift keyed) modem, a convolutional encoder, and a Viterbi decoder. Both modems are designed taking into consideration the fast acquisition of the carrier and bit timing and the low cycle slipping rate in the low-carrier-to-noise-ratio environment. Attention is paid to designing the Viterbi decoder to be operated in a situation in which successive bursts may have different coding rates according to the punctured coding scheme. The overall scheme of the FEC combined modems are presented, and some of the key technologies applied in developing them are outlined. The hardware implementation and experimentation are also discussed. The measured data are compared with results of theoretical analysis, and relatively good performances are obtained.

  16. ERDC-CERL LD-870 Download Program Developed for Aberdeen Test Center: User’s Manual

    DTIC Science & Technology

    2007-05-01

    Conexant 56k internal modem , supplied by Dell, different Rockwell chipset The current modem string is: AT&F X4 E0 Q0 V1 T M0 W2 S0=5 S12=0 &D2 &W...noise monitors. It provides a trouble- shooting guide for resolving known issues with the monitoring system and contains information regarding modem ...20 Unit is dialed, modem responds with “No Carrier

  17. Analysis of Government Facsimile Equipment and Networks

    DTIC Science & Technology

    1991-05-01

    between a STANAG compliant Crt equipment and a Group 3 compliant equipment. Both the modems and the protocols are different. The one-dimensional portion...because Group 3 is neither purely digital nor purely analog. Group 3 uses both: on the PSTN an analog modem provides the carrier for the digital...messages. To use a Group 3 equipment on a digital link at least two approaches can be taken: first, the modem can be bypassed, or second, a second modem

  18. Performance Results of Some Candidate French Modems for the Aeronautical Satellite Communication Channel

    DOT National Transportation Integrated Search

    1978-05-01

    Five candidate data, voice, and ranging modems were evaluated by the AEROSAT channel simulation facility to determine applicability for use in the aeronautical satellite communication channel for air traffic control. The modems were supplied by Telec...

  19. Development and Evaluation of Fault-Tolerant Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Song, Yong D.; Gupta, Kajal (Technical Monitor)

    2004-01-01

    The research is concerned with developing a new approach to enhancing fault tolerance of flight control systems. The original motivation for fault-tolerant control comes from the need for safe operation of control elements (e.g. actuators) in the event of hardware failures in high reliability systems. One such example is modem space vehicle subjected to actuator/sensor impairments. A major task in flight control is to revise the control policy to balance impairment detectability and to achieve sufficient robustness. This involves careful selection of types and parameters of the controllers and the impairment detecting filters used. It also involves a decision, upon the identification of some failures, on whether and how a control reconfiguration should take place in order to maintain a certain system performance level. In this project new flight dynamic model under uncertain flight conditions is considered, in which the effects of both ramp and jump faults are reflected. Stabilization algorithms based on neural network and adaptive method are derived. The control algorithms are shown to be effective in dealing with uncertain dynamics due to external disturbances and unpredictable faults. The overall strategy is easy to set up and the computation involved is much less as compared with other strategies. Computer simulation software is developed. A serious of simulation studies have been conducted with varying flight conditions.

  20. REMOTE: Modem Communicator Program for the IBM personal computer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McGirt, F.

    1984-06-01

    REMOTE, a Modem Communicator Program, was developed to provide full duplex serial communication with arbitrary remote computers via either dial-up telephone modems or direct lines. The latest version of REMOTE (documented in this report) was developed for the IBM Personal Computer.

  1. Development of a System to Validate Group 3 Facsimile Equipment. Phase I.

    DTIC Science & Technology

    1981-07-01

    such as modem , equalizer, line connection etc.) in hardware is. unavoidable. 3. Unless computer and test equipment are co-resident, hardware will be...network simulator. Most of this hardware/firmware has been developed for data transmission in general (v.27 ter/V.29 modems )or specifically for Group 3...system with the facsimile unit under test. 2. V.27 ter/V.29 modems - to handle facsimile data at the various data rate. 3. Modem control and switching

  2. Analysis of United States’ Broadband Policy

    DTIC Science & Technology

    2007-03-01

    compared with the minimum speed the FCC uses in its definition of broadband access. For example, using a 56K modem connection to download a 10...transmission rates multiple times faster than a 56K modem , users can view video or download software and other data-intensive files in a matter of seconds...boast download speeds from 144Kbps (roughly three times faster than a 56K dial-up modem connection) to 2.4Mbps (close to cable- modem speed). Although

  3. Work-Family Balance and Energy: A Day-Level Study on Recovery Conditions

    ERIC Educational Resources Information Center

    Sanz-Vergel, Ana Isabel; Demerouti, Evangelia; Moreno-Jimenez, Bernardo; Mayo, Margarita

    2010-01-01

    The present study examines whether daily recovery inhibiting and enhancing conditions predict day-levels of work-family conflict (WFC), work-family facilitation (WFF), exhaustion and vigor. Forty-nine individuals from various professional backgrounds in Spain provided questionnaire and daily survey measures over a period of five working days.…

  4. TOPEX SDR Processing, October 1998. Volume 4

    NASA Technical Reports Server (NTRS)

    Lee, Jeffrey E.; Lockwood, Dennis W.

    2003-01-01

    This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Sensor Data Record (SDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

  5. Command Flight Path Display. Phase I and II.

    DTIC Science & Technology

    1983-09-01

    transmissions over the standard 56K baud interface. The PS-300 was a commercial unit and required some modifications to ensure its reliability in an...1 H7750-AA Battery Backup NADC 5 Oct E2 9 1 LA-12D Decwriter SAI/RtS 4 11ov 82 10 1 BC03M-25 Null Modem Cable SAI/RM0S 4 Nov 82 35 2 ~%*~’ .5°’ 11 1...of about 1200 baud. (The interface hardware is capable of 56K baud transmission, but the standard PS-300 firmware is only able to process input

  6. Impact of Satellite Aeronautical Channel on Modem Specifications : Phase II. Oceanic Multipath Measurements and Modem Concepts

    DOT National Transportation Integrated Search

    1975-01-01

    The report completes the analysis initiated in the Phase I report of the effects of oceanic multipath on ranging and data modems for satellite air traffic control systems. The interaction between multipath antenna and apparent measured multipath is d...

  7. Impact of Satellite Aeronautical Channel on Modem Specifications : Phase II. Oceanic Multipath Measurements and Modem Concepts

    DOT National Transportation Integrated Search

    1975-01-01

    This report completes the analysis inititaed in the Phase I report of the effects of oceanic multipath on ranging and data modems for satellite air traffic control systems. The interaction between multipath antenna and apparent measured multipath is ...

  8. Air Traffic Control Experimentation and Evaluation with the NASA ATS-6 Satellite : Volume 6. Modem Evaluation Test

    DOT National Transportation Integrated Search

    1976-09-01

    Results of performance evaluation of voice, digital data and ranging modems in the aeronautical satellite environment are given. Approximately 80 hours of modem performance data were acquired on board an FAA KC-135 jet aircraft operating over the Nor...

  9. Recommended Practice for Securing Control System Modems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    James R. Davidson; Jason L. Wright

    2008-01-01

    This paper addresses an often overlooked “backdoor” into critical infrastructure control systems created by modem connections. A modem’s connection to the public telephone system is similar to a corporate network connection to the Internet. By tracing typical attack paths into the system, this paper provides the reader with an analysis of the problem and then guides the reader through methods to evaluate existing modem security. Following the analysis, a series of methods for securing modems is provided. These methods are correlated to well-known networking security methods.

  10. Advanced On-the-Job Training System: Transition Plan

    DTIC Science & Technology

    1990-05-01

    992NP. The 992NP is connected to the UDS CSU/DSU 56K modem with standard telephone wire (four wire). The 56K modem is connected to the 56K communications...UDS CSU/DSU 56K modems . One 56K line from Brooks is connected to Building 428 and the other line is connected to Building 1101. Building 1101 acts as...the central communications node at Bergstrom AFB as illustrated in Figure A- 4. The 56K lines from Brooks are connected to the 56K modems which are in

  11. Two way time transfer results at NRL and USNO

    NASA Technical Reports Server (NTRS)

    Galysh, Ivan J.; Landis, G. Paul

    1993-01-01

    The Naval Research Laboratory (NRL) has developed a two way time transfer modem system for the United States Naval Observatory (USNO). Two modems in conjunction with a pair of Very Small Aperture Terminal (VSAT) and a communication satellite can achieve sub nanosecond time transfer. This performance is demonstrated by the results of testing at and between NRL and USNO. The modems use Code Division Multiple Access (CDMA) methods to separate their signals through a single path in the satellite. Each modem transmitted a different Pseudo Random Noise (PRN) code and received the others PRN code. High precision time transfer is possible with two way methods because of reciprocity of many of the terms of the path and hardware delay between the two modems. The hardware description was given in a previous paper.

  12. A multi-rate DPSK modem for free-space laser communications

    NASA Astrophysics Data System (ADS)

    Spellmeyer, N. W.; Browne, C. A.; Caplan, D. O.; Carney, J. J.; Chavez, M. L.; Fletcher, A. S.; Fitzgerald, J. J.; Kaminsky, R. D.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Mikulina, O. V.; Murphy, R. J.; Rao, H. G.; Scheinbart, M. S.; Seaver, M. M.; Wang, J. P.

    2014-03-01

    The multi-rate DPSK format, which enables efficient free-space laser communications over a wide range of data rates, is finding applications in NASA's Laser Communications Relay Demonstration. We discuss the design and testing of an efficient and robust multi-rate DPSK modem, including aspects of the electrical, mechanical, thermal, and optical design. The modem includes an optically preamplified receiver, an 0.5-W average power transmitter, a LEON3 rad-hard microcontroller that provides the command and telemetry interface and supervisory control, and a Xilinx Virtex-5 radhard reprogrammable FPGA that both supports the high-speed data flow to and from the modem and controls the modem's analog and digital subsystems. For additional flexibility, the transmitter and receiver can be configured to support operation with multi-rate PPM waveforms.

  13. An Overview of the NASA P-3B Airborne Laboratory

    NASA Technical Reports Server (NTRS)

    Guillory, Anthony R.; Postell, George W.

    2009-01-01

    The National Aeronautics and Space Administration (NASA) Wallops Flight Facility (WFF) P-3B Orion is a medium-lift, four engine turbo-prop aircraft that has been reconfigured from a military aircraft to an Earth Science research platform. The aircraft has a long history of supporting science missions, flying on average over 200 hours per year. Examples of research missions that have been flown aboard the aircraft are remote sensing flights to study geophysical parameters including ice-sheet topography and periodic change, soil moisture content, atmospheric aerosol constituents, and beach erosion. Missions are conducted for the purposes of calibration/validation of various NASA and international satellites that monitor climate change as well as process studies and the test of new prototype remote sensing instruments. In recent y ears the focus has been on ice surveys of the Arctic and Antarctic, soil moisture research, and measurements of atmospheric chemistry and radiation sciences. The aircraft has been conducting ice surveys of Greenland since 1993 for the purposes of topographic mapping of both the surface and basal topography. Another application of the aircraft has been for soil moisture research. Research has also been conducted using microwave radiometers and radars over various agricultural and forest lands. Recently, a mission was flown in the spring over the High-Arctic to collect air samples of haze and boreal forest fires in an effort to determine anthropogenic amounts and sources of pollution. This pa per will provide an overview of the P-3B platform and highlight recent science missions.

  14. 76 FR 36154 - In the Matter of Certain Equipment for Communications Networks, Including Switches, Routers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ... Communications Networks, Including Switches, Routers, Gateways, Bridges, Wireless Access Points, Cable Modems, IP... networks, including switches, routers, gateways, bridges, wireless access points, cable modems, IP phones... points, cable modems, IP phones, and products containing same that infringe one or more of claims 1, 5, 9...

  15. Textural and Carbon Isotopic Analyses of Modern Carbonate Microbialites: Possible Ancient and Martian Analogs

    NASA Technical Reports Server (NTRS)

    Thompson, Joel B.

    1998-01-01

    Many modem and ancient carbonate deposits around the world have been recognized as microbial buildups or microbialites. Ancient microbialite structures have been divided into two basic categories based on their internal fabric or texture. They include stromatolites which have a predominantly laminated internal fabric and thrombolites which have an open-porous clotted fabric, that lacks laminae. The origin of these two basic microbial fabrics is still being debated in the literature. Understanding the origin and the various microorganisms involved in forming these modem fabrics is the key to the interpretation of similar fabrics in ancient and possibly Martian rocks. Therefore, detailed studies are needed on the microbiological makeup and origin of the fabrics in modem microbialites. Such studies may serve as analogs for ancient and Martian microbialites in the future. The purpose of this study is to examine the textures and carbon isotopic signatures of the following modem microbialites from the Bahamas: 1) a modem subtidal microbialite from Iguana Cay, Bahamas and 2) a modem microbial mat (stromatolite) from a hypersaline pond on Lee Stocking Island, Bahamas.

  16. Dolphin Sounds-Inspired Covert Underwater Acoustic Communication and Micro-Modem

    PubMed Central

    Qiao, Gang; Liu, Songzuo; Bilal, Muhammad

    2017-01-01

    A novel portable underwater acoustic modem is proposed in this paper for covert communication between divers or underwater unmanned vehicles (UUVs) and divers at a short distance. For the first time, real dolphin calls are used in the modem to realize biologically inspired Covert Underwater Acoustic Communication (CUAC). A variety of dolphin whistles and clicks stored in an SD card inside the modem helps to realize different biomimetic CUAC algorithms based on the specified covert scenario. In this paper, the information is conveyed during the time interval between dolphin clicks. TMS320C6748 and TLV320AIC3106 are the core processors used in our unique modem for fast digital processing and interconnection with other terminals or sensors. Simulation results show that the bit error rate (BER) of the CUAC algorithm is less than 10−5 when the signal to noise ratio is over ‒5 dB. The modem was tested in an underwater pool, and a data rate of 27.1 bits per second at a distance of 10 m was achieved. PMID:29068363

  17. TOPEX Software Document Series. Volume 5; Rev. 1; TOPEX GDR Processing

    NASA Technical Reports Server (NTRS)

    Lee, Jeffrey; Lockwood, Dennis; Hancock, David W., III

    2003-01-01

    This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Geophysical Data Record (GDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

  18. Performances of a date dissemination code on telephone lines using commercial modems

    NASA Technical Reports Server (NTRS)

    Cordara, F.; Pettiti, V.; Quasso, R.; Rubiola, E.

    1993-01-01

    A coded time/date information dissemination system (CTD), based on telephone lines and commercial modems, is now in its experimental phase in Italy at IEN. This service, born from a cooperation with other metrological laboratories (TUG, Austria, SNT, Sweden, VSL, The Netherlands), represents an attempt towards an European standardization. Some results of an experimental analysis in which a few modems were tested, both in laboratory conditions and connected to the telephone network, in order to evaluate the timing capability of the system are given. When the system is used in a one-way mode, in many practical cases the modems delay turns out to be the main factor which limits the accuracy, even more than the telephone line delays. If the two-way mode is used, the modems asymmetry, i.e., the delay difference between transmission and reception, is almost always the most important source of uncertainty, provided the link is not including a space segment. Comparing the widely used V.22 modems to the old V.21 ones, the latters turn out to be better both in delay time (30-100 ms V.22, and 7-15 ms V.21) and asymmetry (10-50 micro-s V.22, and 10 ms V.22). Time transfer accuracies of 10 micron-s (same turn) to 100 micro-s (long distance calls) were obtained in two-way mode with commercial V.21 modems.

  19. Model verifies design of mobile data modem

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Sumida, J.

    1986-01-01

    It has been proposed to use differential minimum shift keying (DMSK) modems in spacecraft-based mobile communications systems. For an employment of these modems, it is necessary that the transmitted carrier frequency be known prior to signal detection. In addition, the time needed by the receiver to lock onto the carrier frequency must be minimized. The present article is concerned with a DMSK modem developed for the Mobile Satellite Service. This device demonstrated fast acquisition time and good performance in the presence of fading. However, certain problems arose in initial attempts to study the acquisition behavior of the AFC loop through breadboard techniques. The development of a software model of the AFC loop is discussed, taking into account two cases which were plotted using the model. Attention is given to a demonstration of the viability of the modem by an approach involving modeling and analysis of the frequency synchronizer.

  20. Bandwidth Efficient Wireless Digital Modem Developed

    NASA Technical Reports Server (NTRS)

    Kifle, Muli

    1999-01-01

    NASA Lewis Research Center has developed a digital approach for broadcasting highfidelity audio (nearly compact disk (CD) quality sound) in the commercial frequencymodulated (FM) broadcast band. This digital approach provides a means of achieving high data transmission rates with low hardware complexity--including low mass, size, and power consumption. Lewis has completed the design and prototype development of a bandwidth-efficient digital modem (modulator and demodulator) that uses a spectrally efficient modulation scheme: 16-ary rectangular quadrature amplitude modulation, or 16- ary QAM. The digital implementation is based strictly on inexpensive, commercial off-theshelf digital signal processing (DSP) hardware to perform up and down conversions and pulse shaping. The digital modem transmits data at rates up to 76 kilobits per second (kbps), which is almost 3 times faster than standard 28.8-kbps telephone modems. In addition, the modem offers improved power and spectral performance, flexible operation, and low-cost implementation.

  1. Comparison of Online Costs Using 1200-BPS and 2400-BPS Modems.

    ERIC Educational Resources Information Center

    MacMillan, Donald

    1992-01-01

    Compares search time and costs of four online searches, identically replicated except for the speed of the modem used to retrieve and download data. Results are presented for 1200-BPS (bits per second) and 2400-BPS modems which demonstrate that searching at 2400-BPS is more efficient and economical. Issues to be resolved before 9600-BPS modems…

  2. Audio-Visual Situational Awareness for General Aviation Pilots

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    Weather is one of the major causes of general aviation accidents. Researchers are addressing this problem from various perspectives including improving meteorological forecasting techniques, collecting additional weather data automatically via on-board sensors and "flight" modems, and improving weather data dissemination and presentation. We approach the problem from the improved presentation perspective and propose weather visualization and interaction methods tailored for general aviation pilots. Our system, Aviation Weather Data Visualization Environment (AWE), utilizes information visualization techniques, a direct manipulation graphical interface, and a speech-based interface to improve a pilot's situational awareness of relevant weather data. The system design is based on a user study and feedback from pilots.

  3. Baseband processor development for the Advanced Communications Satellite Program

    NASA Technical Reports Server (NTRS)

    Moat, D.; Sabourin, D.; Stilwell, J.; Mccallister, R.; Borota, M.

    1982-01-01

    An onboard-baseband-processor concept for a satellite-switched time-division-multiple-access (SS-TDMA) communication system was developed for NASA Lewis Research Center. The baseband processor routes and controls traffic on an individual message basis while providing significant advantages in improved link margins and system flexibility. Key technology developments required to prove the flight readiness of the baseband-processor design are being verified in a baseband-processor proof-of-concept model. These technology developments include serial MSK modems, Clos-type baseband routing switch, a single-chip CMOS maximum-likelihood convolutional decoder, and custom LSL implementation of high-speed, low-power ECL building blocks.

  4. Two Nights on a Flying Observatory: A KAO Journal

    NASA Technical Reports Server (NTRS)

    Stryker, Pam; Willis, Marsha

    1994-01-01

    We are the first participants in the "Science in the Stratosphere" program, sponsored by NASA and the University of Texas at Austin. The purpose of the program is to bring the techniques and excitement of modem astronomy into the classroom. Our job is to become familiar with the normal KAO operations, and learn from the staff and scientists during an actual observing flight. We are going to fly on missions to observe galactic and extragalactic star-forming regions in the far infrared region of the spectrum. All of our expectations spring from this simple working description. Little do we know, however, what really lies ahead for us!

  5. Design and implementation of an omni-directional underwater acoustic micro-modem based on a low-power micro-controller unit.

    PubMed

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication.

  6. 76 FR 43616 - Procedures for Implementing the National Environmental Policy Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... Studies. 4. NASA HQ 09/23/2009 ARRA Implementation of Venture-Class Mission, HQ ID-1095. 5. LaRC, VA 11/20.../2009 Develop Air Traffic Management Concepts. 5. NASA HQ 12/23/2009 ARRA-Funded Activities (HQ ID-1119... Composition, Cloud, Climate Coupling (TC-4). 3. WFF, VA 03/28/2008 ARCTAS Mission. The third proposed CatEx...

  7. Combination of oriented partial differential equation and shearlet transform for denoising in electronic speckle pattern interferometry fringe patterns.

    PubMed

    Xu, Wenjun; Tang, Chen; Gu, Fan; Cheng, Jiajia

    2017-04-01

    It is a key step to remove the massive speckle noise in electronic speckle pattern interferometry (ESPI) fringe patterns. In the spatial-domain filtering methods, oriented partial differential equations have been demonstrated to be a powerful tool. In the transform-domain filtering methods, the shearlet transform is a state-of-the-art method. In this paper, we propose a filtering method for ESPI fringe patterns denoising, which is a combination of second-order oriented partial differential equation (SOOPDE) and the shearlet transform, named SOOPDE-Shearlet. Here, the shearlet transform is introduced into the ESPI fringe patterns denoising for the first time. This combination takes advantage of the fact that the spatial-domain filtering method SOOPDE and the transform-domain filtering method shearlet transform benefit from each other. We test the proposed SOOPDE-Shearlet on five experimentally obtained ESPI fringe patterns with poor quality and compare our method with SOOPDE, shearlet transform, windowed Fourier filtering (WFF), and coherence-enhancing diffusion (CEDPDE). Among them, WFF and CEDPDE are the state-of-the-art methods for ESPI fringe patterns denoising in transform domain and spatial domain, respectively. The experimental results have demonstrated the good performance of the proposed SOOPDE-Shearlet.

  8. Using Modern Design Tools for Digital Avionics Development

    NASA Technical Reports Server (NTRS)

    Hyde, David W.; Lakin, David R., II; Asquith, Thomas E.

    2000-01-01

    Using Modem Design Tools for Digital Avionics Development Shrinking development time and increased complexity of new avionics forces the designer to use modem tools and methods during hardware development. Engineers at the Marshall Space Flight Center have successfully upgraded their design flow and used it to develop a Mongoose V based radiation tolerant processor board for the International Space Station's Water Recovery System. The design flow, based on hardware description languages, simulation, synthesis, hardware models, and full functional software model libraries, allowed designers to fully simulate the processor board from reset, through initialization before any boards were built. The fidelity of a digital simulation is limited to the accuracy of the models used and how realistically the designer drives the circuit's inputs during simulation. By using the actual silicon during simulation, device modeling errors are reduced. Numerous design flaws were discovered early in the design phase when they could be easily fixed. The use of hardware models and actual MIPS software loaded into full functional memory models also provided checkout of the software development environment. This paper will describe the design flow used to develop the processor board and give examples of errors that were found using the tools. An overview of the processor board firmware will also be covered.

  9. A spread-spectrum modem using constant envelope BPSK for a mobile satellite communications terminal

    NASA Technical Reports Server (NTRS)

    Iizuka, N.; Yamashita, A.; Takenaka, S.; Morikawa, E.; Ikegami, T.

    1990-01-01

    This paper describes a 5-kilobit/s spread spectrum modem with a 1.275 mega-Hz chip rate for mobile satellite communications. We used a Viterbi decoder with a coding gain of 7.8 dB at a BER of 10(exp -5) to decrease the required receiver power. This reduces the cost of communication services. The spread spectrum technique makes the modem immune to terrestrial radio signals and keeps it from causing interference in terrestrial radio systems. A class C power amplifier reduces the modem's power consumption. To avoid nonlinear distortion caused by the amplifier, the envelope of the input signal is kept constant by adding quadrature channel signal to the BPSK signal. To simulate the worst case, we measured the modem's output spectrum using a limiting amplifier instead of the class C amplifier, and found that 99 percent of the spectral power was confined to the specified 2.55 mega-Hz bandwidth.

  10. High Speed Network Access to the Last-Mile Using Fixed Broadband Wireless

    DTIC Science & Technology

    2004-03-01

    could download the 3¼-hour movie Titanic in 7 minutes and 23 seconds while a 56K modem on the other hand would need almost 22 hours”. The MMDS band...9 a. Twisted Copper Pair (xDSL).....................................................9 b. Cable Modem ...of dial-up modems over twisted copper pair1. Copper wire provided the link in the local loop between the telephone subscriber and the local

  11. M/A-COM Linkabit Eastern Operations

    DTIC Science & Technology

    1983-03-31

    Lincoln Laboratories speech codec for use in multimedia system development. Communication equipment included 1200-bps dial-up modems and a set of...connected to the DCN for use in[7, Page 4 general word-processing and network-testing applications.Additional modems and video terminals have also been...line 0) can be connected to a second terminal, a printer, or a modem . The standard configuration assumes this line is connected to a terminal or

  12. Modem design for a MOBILESAT terminal

    NASA Technical Reports Server (NTRS)

    Rice, M.; Miller, M. J.; Cowley, W. G.; Rowe, D.

    1990-01-01

    The implementation is described of a programmable digital signal processor based system, designed for use as a test bed in the development of a digital modem, codec, and channel simulator. Code was written to configure the system as a 5600 bps or 6600 bps QPSK modem. The test bed is currently being used in an experiment to evaluate the performance of digital speech over shadowed channels in the Australian mobile satellite (MOBILESAT) project.

  13. Recent Developments in Balloon Support Instrumentation at TIFR Balloon Facility, Hyderabad.

    NASA Astrophysics Data System (ADS)

    Vasudevan, Rajagopalan

    2012-07-01

    The Balloon Facility of Tata Institute of Fundamental Research has been conducting stratospheric balloon flights regularly for various experiments in Space Astronomy and Atmospheric Sciences. A continuous improvement in Balloon flight Support instrumentation by the Control Instrumentation Group to keep in space with the growing complexities of the scientific payloads have contributed to the total success of balloon flights conducted recently. Recent improvements in display of Balloon position during balloon flight by showing on real time the balloon GPS position against Google TM maps is of immense help in selecting the right spot for payload landing and safe recovery . For further speeding up the payload recovery process, a new GPS-GSM payload system has been developed which gives SMS of the payload position information to the recovery team on their cell phones. On parallel footing, a new GPS- VHF system has been developed using GPS and Radio Modems for Balloon Tracking and also for obtaining the payload impact point. On the Telecommand side, a single board Telecommand/ Timer weighing less than 2 Kg has been specially developed for use in the mesosphere balloon test flight. The interference on the existing Short Range Telemetry System has been eliminated by introducing a Band Pass Filter and LNA in the Receiving system of the modules, thereby enhancing its reliability. In this paper , we present the details of the above mentioned developments.

  14. Resource Allocation Games: A Priming Game for a Series of Instructional Games (The POE Game).

    ERIC Educational Resources Information Center

    Allen, Layman E.

    This paper describes in detail the paper-and-pencil POE (Pelham Odd 'R Even) game, in which units of space are the allocated resources. The game is designed to provide an introduction to the rule structure common to the games of EQUATIONS, WFF 'N PROOF, and ON-SENTS & NON-SENTS. Techniques of playing POE, including goals, solutions, moves, scoring…

  15. DDN (Defense Data Network) Protocol Implementations and Vendors Guide

    DTIC Science & Technology

    1987-08-01

    length. Lower rates can be selected or determined by attached modem types 303, 209, V.35, or 188-114. Units are in pairs, one at each end of the...ECUs communicate with the IMP via direct cable or modems . DOCUMENTATION: Fully documented vendor product; descriptive literature available...terminals, PCs and modems to an Ethernet. The device can support up to 80 lines and 2 parallel printers. Full domain naming is supported as well as

  16. Advanced Military Pay System Concepts. Evaluation of Opportunities through Information Technology.

    DTIC Science & Technology

    1980-07-01

    trans- mdtter (UART) to interface with a modem . The main processor was then responsible for input and output between main memory and the UART...digital, "run-length" encoding scheme which is very effective in reducing the amount of data to be transmitted. Machines of this type include a modem ...Output control as well as data compression will be combined with appropriate modems or interfaces to digital transmission channels and microprocessor

  17. Satellite Data Transmission (SDT) requirement

    NASA Technical Reports Server (NTRS)

    Chie, C. M.; White, M.; Lindsey, W. C.

    1984-01-01

    An 85 Mb/s modem/codec to operate in a 34 MHz C-band domestic satellite transponder at a system carrier to noise power ratio of 19.5 dB is discussed. Characteristics of a satellite channel and the approach adopted for the satellite data transmission modem/codec selection are discussed. Measured data and simulation results of the existing 50 Mbps link are compared and used to verify the simulation techniques. Various modulation schemes that were screened for the SDT are discussed and the simulated performance of two prime candidates, the 8 PSK and the SMSK/2 are given. The selection process that leads to the candidate codec techniques are documented and the technology of the modem/codec candidates is assessed. Costs of the modems and codecs are estimated.

  18. An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

    PubMed Central

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

  19. An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

    PubMed

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

  20. The Cognitive Consequences of Patterns of Information Flow

    NASA Technical Reports Server (NTRS)

    Hutchins, Edwin

    1999-01-01

    The flight deck of a moderm commercial airliner is a complex system consisting of two or more crew and a suite of technological devices. When everything goes right, all modem flight decks are easy to use. When things go sour, however, automated flight decks provide opportunities for new kinds of problems. A recent article in Aviation Week cited industry concern over the problem of verifying the safety of complex systems on automated, digital aircraft, stating that the industry must "guard against the kind of incident in which people and the automation seem to mismanage a minor occurrence or non-routine situation into larger trouble." The design of automated flight deck systems that flight crews find easy to use safely is a challenge in part because this design activity requires a theoretical perspective which can simultaneously cover the interactions of people with each other and with technology. In this paper, I will introduce some concepts that can be used to understand the flight deck as a system that is composed of two or more pilots and a complex suite of automated devices. As I will try to show, without a theory, we can repeat what seems to work, but we may not know why it worked or how to make it work in novel circumstances. Theory allows us to rise above the particulars of specific situations and makes the application of the roots of success in one setting applicable to other settings.

  1. Modem Signature Analysis.

    DTIC Science & Technology

    1982-10-01

    AD-A127 993 MODEM SIGNATURE ANALISIS (U) PAR TECHNOLOGY CORP NEW / HARTFORD NY V EDWARDS ET AL. OCT 82 RADC-TR-82-269 F30602-80-C-0264 NCLASSIFIED F/G...as an indication of the class clustering and separation between different classes in the modem data base. It is apparent from the projection that the...that as the clusters disperse, the likelihood of a sample crossing the boundary into an adjacent region and causing a symbol decision error increases. As

  2. Analysis of Delays in Transmitting Time Code Using an Automated Computer Time Distribution System

    DTIC Science & Technology

    1999-12-01

    jlevine@clock. bldrdoc.gov Abstract An automated computer time distribution system broadcasts standard tune to users using computers and modems via...contributed to &lays - sofhareplatform (50% of the delay), transmission speed of time- codes (25OA), telephone network (lS%), modem and others (10’4). The... modems , and telephone lines. Users dial the ACTS server to receive time traceable to the national time scale of Singapore, UTC(PSB). The users can in

  3. WES (Waterways Experiment Station) Communications Plan for Voice and Data

    DTIC Science & Technology

    1989-01-01

    modem on a leased line, and two wideband HDLC 56K connections not used on the Honeywell. 30. Honeywell DPS-8 configuration, as of October 1987, is as...based voice system to support additional asynchronous dial-up modem traffic. In June 1987, Dr. N. Radhakhrishnan of the WES Information Technology...voice system (PBX) and very low-speed data communications by the laboratories using 1,200/2,400-baud asynchronous modems over analog phone lines, and

  4. DDN (Defense Data Network) Protocol Implementations and Vendors Guide,

    DTIC Science & Technology

    1986-08-01

    3000 feet) in length. Lower rates can be selected or determined by attached modem types 303, 209, V.35, or 188-114. Units are in pairs, one at each...each direction. ECUs communicate with the IMP via direct cable or modems . DOCUMENTATION: Fully documented vendor product; descriptive literature...application is the attachment of terminals, PCs and modems to an Ethernet. The device can support up to 80 lines and 2 parallel printers. Full domain naming

  5. Coding and Modulation for LMDS and Analysis of the LMDS Channel

    PubMed Central

    Håkegård, Jan Erik

    2000-01-01

    Local Multipoint Distribution Service (LMDS) has the potential to become a viable alternative to coaxial cable, fiber and other wired and wireless technologies providing “last mile” communication services. A major obstacle, however, is the high equipment cost. While for example cable modems supporting two-way services are available for $200 to $300, LMDS modem providing similar services will cost over $1000. The major cost driver of LMDS equipment is the radio frequency (RF) unit, as Ka-band technology still is quite expensive. The modem design must minimize the overall architecture cost, and low-cost modems requiring an expensive architecture should not be used. The channel characteristics of LMDS systems are very different from those of fiber, coaxial cable, and lower frequency wireless links, major channel impairments being non-linear high power amplifier (HPA), high phase noise and high co-channel interference. Modems should therefore be developed specifically for LMDS systems. This report deals with the choice of coding and modulation schemes, the LMDS channel, and how the channel impairments should be overcome by digital signal processing algorithms. PMID:27551634

  6. Conversion from Engineering Units to Telemetry Counts on Dryden Flight Simulators

    NASA Technical Reports Server (NTRS)

    Fantini, Jay A.

    1998-01-01

    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 one-count 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 modem 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.

  7. Apparatus and Method for Communication over Power Lines

    NASA Technical Reports Server (NTRS)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor); Greer, III, Lawrence C. (Inventor); Nappier, Jennifer M. (Inventor)

    2017-01-01

    An apparatus and method are provided for communicating over power lines. The apparatus includes a coupling modem that is situated between a power line and a device. The coupling modem is configured to demodulate a signal received from the power line into a sine signal and a cosine signal. The coupling modem is also configured to modulate a communicated bit stream received from the device into a transmitted signal in order to impose the transmitted signal onto the power line.

  8. An Impact Assessment Model for Distributed Adaptive Security Situation Assessment

    DTIC Science & Technology

    2005-01-01

    the cargo manifest can be either a 56K modem-based TCP/IP connection (the oval labeled internet) or a 40K wireless modem connection ( cell phone ) that...via a UDP connection on the 40K wireless modem ( cell phone ). For each resource, either alternative may be used to achieve the same goal, but some...Manifests Comm-in Comp- power Comm- out JTF Internet (TCP-IP) Cell phone (TCP-IP) Internet (UDP) Cell phone (UDP) Manual Computer 4

  9. Enhancing Network Communication in NPSNET-V Virtual Environments Using XML-Described Dynamic Behavior (DBP) Protocols

    DTIC Science & Technology

    2001-09-01

    testing is performed between two machines connected by either a 100 Mbps Ethernet connection or a 56K modem connection. This testing is performed...and defined as follows: • The available bandwidth is set at two different levels (Ethernet 100 Mbps and 56K modem ). 32 • The packet size is set... modem connection. These two connections represent the target 100 Mbps high end and 56k bps low end of anticipated client connections in web-based

  10. Computer Algorithms and Architectures for Three-Dimensional Eddy-Current Nondestructive Evaluation. Volume 3. Chapters 6-11

    DTIC Science & Technology

    1989-01-20

    addressable memory can be loaded or off- loaded as the number crunching continues. Modem VLSI processors can often process data faster than today’s...Available DSP Chips Texas Instruments was one of the first serious manufacturers of DSP chips. With the Texas Instruments TMS310 DSP chip, modem , voice...Can handle double presicion data types. Texas Instruments TMS32010 T’s first-generation DSP design: a fixed-point DSP that has found its way into modem

  11. Overview of Research Activities on Time and Frequency at the National Institute of Information and Communications Technology

    DTIC Science & Technology

    2004-12-01

    FREQUENCY TRANSFER ( TWSTFT ) TWSTFT network in the Asia-Pacific region has developed by the collaboration of NICT and major T&F institutes in the...region [7]. A multi-channel TWSTFT modem has been developed by NICT. The performance evaluation shows that it is capable of sub-nanosecond time...intercomparison of NICT modem TWSTFT , ATLANTIS modem TWSTFT , and GPS common view (CV) in the case of the NICT-TL link is shown in Figure 4, and the stability

  12. Apparatus and Method for Communication over Power Lines

    NASA Technical Reports Server (NTRS)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor); Greer, Lawrence C., III (Inventor); Nappier, Jennifer M. (Inventor)

    2015-01-01

    An apparatus and method are provided for communicating over power lines. The apparatus includes a coupling modem that is situated between a power line and a device. The coupling modem is configured to demodulate a signal received from the power line into a sine signal and a cosine signal. The coupling modem is also configured to modulate a communicated bit stream received from the device into a transmitted signal in order to impose the transmitted signal onto the power line.

  13. Digital Tone Ranging Modem.

    DOT National Transportation Integrated Search

    1976-05-01

    This report describes a digital ranging modem implementation based on side-tone ranging concepts. The ranging technique implemented and tested in the DOT/TSC avionics laboratory has direct application to the AEROSAT surveillance system. The performan...

  14. Detection probability of EBPSK-MODEM system

    NASA Astrophysics Data System (ADS)

    Yao, Yu; Wu, Lenan

    2016-07-01

    Since the impacting filter-based receiver is able to transform phase modulation into amplitude peak, a simple threshold decision can detect the Extend-Binary Phase Shift Keying (EBPSK) modulated ranging signal in noise environment. In this paper, an analysis of the EBPSK-MODEM system output gives the probability density function for EBPSK modulated signals plus noise. The equation of detection probability (pd) for fluctuating and non-fluctuating targets has been deduced. Also, a comparison of the pd for the EBPSK-MODEM system and pulse radar receiver is made, and some results are plotted. Moreover, the probability curves of such system with several modulation parameters are analysed. When modulation parameter is not smaller than 6, the detection performance of EBPSK-MODEM system is more excellent than traditional radar system. In addition to theoretical considerations, computer simulations are provided for illustrating the performance.

  15. Testing and performance analysis of a 650 Mbps QPPM modem for free-space laser communications

    NASA Astrophysics Data System (ADS)

    Mortensen, Dale J.

    1994-08-01

    The testing and performance of a prototype modem developed at NASA Lewis Research Center for high-speed free-space direct detection optical communications is described. The testing was performed under laboratory conditions using computer control with specially developed test equipment that simulates free-space link conditions. The modem employs quaternary pulse position modulation (QPPM) at 325 Megabits per second (Mbps) on two optical channels, which are multiplexed to transmit a single 650 Mbps data stream. The measured results indicate that the receiver's automatic gain control (AGC), phased-locked-loop slot clock recovery, digital symbol clock recovery, matched filtering, and maximum likelihood data recovery circuits were found to have only 1.5 dB combined implementation loss during bit-error-rate (BER) performance measurements. Pseudo random bit sequences and real-time high quality video sources were used to supply 650 Mbps and 325 Mbps data streams to the modem. Additional testing revealed that Doppler frequency shifting can be easily tracked by the receiver, that simulated pointing errors are readily compensated for by the AGC circuits, and that channel timing skew affects the BER performance in an expected manner. Overall, the needed technologies for a high-speed laser communications modem were demonstrated.

  16. QM/PSK Voice/Data Modem

    DOT National Transportation Integrated Search

    1976-03-01

    Two Quadrature Modulation/Phase Shift Keyed (QM/PSK) Voice/Data Modem systems have been developed as part of the satellite communications hardware for advanced air traffic control systems. These systems consist of a modulator and demodulator unti whi...

  17. Signal Analysis for Aerosat.

    DOT National Transportation Integrated Search

    1972-08-01

    The report addresses signal design for the AEROSAT system. Candidate data and surveillance modems are analyzed for L-Band avionics. Detailed theoretical analyses are presented of the effects of the oceanic satellite-aircraft channel on data modem per...

  18. Local Area Networking Handbook

    DTIC Science & Technology

    1990-06-01

    Number of dcvices IO’s-lOOO’s 10’s. I00Ys W0"s-10O’s supported Attachment cost S500-S50U) S40k-$ 56k S250-SIOOU C. LOCAL AREA NETWORKS Due to the...broadband cable by substituting RF modems for the conventional modems or line drivers. Then control may be imposed through conventional communications link...Ref. 11:p. 33] In a typical broadband bus configuration using FDM, channels are allocated dynamically, using frequency agile RF modems , rather than

  19. Baseband pulse shaping techniques for nonlinearly amplified pi/4-QPSK and QAM systems

    NASA Technical Reports Server (NTRS)

    Feher, Kamilo

    1991-01-01

    A new generation of multi-stage pi/4-shifted QPSK and of superposed quadrature-amplitude-modulated (SQAM) modulators-coherent demodulators (modems) and of continuous phase modulated (CPM)-gaussian premodulation filtered minimum-shift-keying (MGMSK) systems is proposed and studied. These modems will lead to bandwidth and power efficient satellite communications systems designs. As an illustrative application, a baseband processing technique pi/4-controlled transition PSK (pi/4-CTPSK) is described. To develop a cost and power efficient design strategy, we assume that nonlinear, fully saturated high power amplifiers (HPA) are utilized in the satellite earth station transmitter and in the satellite transponder. Modem structures which could lead to application specific integrated circuit (ASIC) satellite on-board processing universal modem applications are also considered. Multistate GMSK (i.e., MGMSK) signal generation methods by means of two or more RF combined nonlinearly amplified SQAM modems and by one multistate (in-phase and quadrature-baseband premodulation filtered-superposed) SQAM architecture and one RF nonlinear amplifier are studied. During the SQAM modem development phase we investigate the potential system advantages of the pi/4-shifted logic. The bandwidth efficiency of the proposed multistate GMSK and baseband filtered PAM-FM modulator (a new class in the CPM family) will be significantly higher than that of conventional G-MSK systems. To optimize the practical P(sub e) = f((E sub b)/(N sub o)) performance we consider improved coherent demodulation MGMSK structures such as deviated-frequency locking coherent demodulators. For relative low bit rate SATCOM applications, e.g., bit rates less than 300 kb/s, phase noise tracking cancellation (for fixed site earth station) and phase noise cancellation as well as Doppler compensation (for satellite to mobile earth station) applications may be required. We study digital channel sounding methods which could cancel the phase noise-caused degradations of CPM and GMSK modems.

  20. Two-Way Radio Modem Data Transfer for Newborn Hearing Screening Devices.

    PubMed

    Matulat, Peter; Lepper, Ingo; Böttcher, Peter; Parfitt, Ross; Oswald, Hans; Am Zehnhoff-Dinnesen, Antoinette; Deuster, Dirk

    2017-01-01

    The success of a newborn hearing screening program depends on successful tracking and follow-up to ensure that children who have had positive screening results in the first few days of life receive appropriate and timely diagnostic and intervention services. The easy availability, through a suitable infrastructure, of the data necessary for the tracking, diagnosis, and care of children concerned is a major key to enhancing the quality and efficiency of newborn hearing screening programs. Two systems for the automated two-way transmission of newborn hearing screening and configuration data, based on mobile communication technology, for the screening devices MADSEN AccuScreen ® and Natus Echo-Screen ® were developed and tested in a field study. Radio modem connections were compared with conventional analogue modem transmissions from Natus Echo-Screen devices for duration, transmission rate, number of lost connections, and frequency of use. The average session duration was significantly lower with the MADSEN AccuScreen (12 s) and Natus Echo-Screen both with radio modem (15 s) than the Natus Echo-Screen with analogue modem (108 s). The transmission rate was significantly higher (898 and 1,758 vs. 181 bytes/s) for the devices with radio modems. Both radio modem devices had significantly lower rates of broken connections after initial connection (2.1 and 0.9 vs. 5.5%). An increase in the frequency of data transmission from the clinics with mobile radio devices was found. The use of mobile communication technology in newborn hearing screening devices offers improvements in the average session duration, transmission rate, and reliability of the connection over analogue solutions. We observed a behavioral change in clinical staff using the new technology: the data exchange with the tracking center is more often used. The requirements for on-site support were reduced. These savings outweigh the small increase in costs for the Internet service provider.

  1. Analog Ranging Modem Code Processor and Generator

    DOT National Transportation Integrated Search

    1974-05-01

    The report details technical development efforts to implement an analog ranging modem using recently developed linear integrated circuits where possible. The breadboard hardware is capable of acquiring frequency and phase of a weak signal in a high n...

  2. Burst Mode ASIC-Based Modem

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The NASA Lewis Research Center is sponsoring the Advanced Communication Technology Insertion (ACTION) for Commercial Space Applications program. The goal of the program is to expedite the development of new technology with a clear path towards productization and enhancing the competitiveness of U.S. manufacturers. The industry has made significant investment in developing ASIC-based modem technology for continuous-mode applications and has made investigations into East, reliable acquisition of burst-mode digital communication signals. With rapid advances in analog and digital communications ICs, it is expected that more functions will be integrated onto these parts in the near future. In addition custom ASIC's can also be developed to address the areas not covered by the other IC's. Using the commercial chips and custom ASIC's, lower-cost, compact, reliable, and high-performance modems can be built for demanding satellite communication application. This report outlines a frequency-hop burst modem design based on commercially available chips.

  3. Nads FSK Modem, LEA 74-2248

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, K.R.

    1976-01-12

    The Nads FSK Modem is a compact unit designed to operate in conjunction with EIA standard interfacing and the data terminal equipment of the 1200 Baud digital communications network of the Nevada Automated Diagnostics System (NADS). The modem is constructed in a Nuclear Instrumentation Module System (NIMS) module for compatability with the NADS system. The modulator section of the modem accepts serial, digital signals at 1200 Baud which may be either standard TTL levels or bipolar signals meeting either the EIA RS-232C or RS-232B standards. The output of the modulator is a Frequency-Shift Keyed (FSK) signal having frequencies of 2.2more » kHz for Mark and 1.2 kHz for Space. The demodulator section accepts the above FSK signal as input, and outputs serial, digital signals at 1200 Baud at either TTL or EIA RS-232C levels. Specifications and operation and calibration instructions are given. (WHK)« less

  4. Investigating mode errors on automated flight decks: illustrating the problem-driven, cumulative, and interdisciplinary nature of human factors research.

    PubMed

    Sarter, Nadine

    2008-06-01

    The goal of this article is to illustrate the problem-driven, cumulative, and highly interdisciplinary nature of human factors research by providing a brief overview of the work on mode errors on modern flight decks over the past two decades. Mode errors on modem flight decks were first reported in the late 1980s. Poor feedback, inadequate mental models of the automation, and the high degree of coupling and complexity of flight deck systems were identified as main contributors to these breakdowns in human-automation interaction. Various improvements of design, training, and procedures were proposed to address these issues. The author describes when and why the problem of mode errors surfaced, summarizes complementary research activities that helped identify and understand the contributing factors to mode errors, and describes some countermeasures that have been developed in recent years. This brief review illustrates how one particular human factors problem in the aviation domain enabled various disciplines and methodological approaches to contribute to a better understanding of, as well as provide better support for, effective human-automation coordination. Converging operations and interdisciplinary collaboration over an extended period of time are hallmarks of successful human factors research. The reported body of research can serve as a model for future research and as a teaching tool for students in this field of work.

  5. Snails, stable iostopes, and southwestern desert paleoclimates

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharpe, S.E.; Whelan, J.F.; Forester, R.M.

    1995-09-01

    Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearingmore » air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.« less

  6. 76 FR 30196 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ... Access Points, Cable Modems, IP Phones, and Products Containing Same, DN 2807; the Commission is..., wireless, access points, cable modems, IP phones, and products containing same. The complaint names as...

  7. The Extended Duration Sounding Rocket (EDSR): Low Cost Science and Technology Missions

    NASA Astrophysics Data System (ADS)

    Cruddace, R. G.; Chakrabarti, S.; Cash, W.; Eberspeaker, P.; Figer, D.; Figueroa, O.; Harris, W.; Kowalski, M.; Maddox, R.; Martin, C.; McCammon, D.; Nordsieck, K.; Polidan, R.; Sanders, W.; Wilkinson, E.; Asrat

    2011-12-01

    The 50-year old NASA sounding rocket (SR) program has been successful in launching scientific payloads into space frequently and at low cost with a 85% success rate. In 2008 the NASA Astrophysics Sounding Rocket Assessment Team (ASRAT), set up to review the future course of the SR program, made four major recommendations, one of which now called Extended Duration Sounding Rocket (EDSR). ASRAT recommended a system capable of launching science payloads (up to 420 kg) into low Earth orbit frequently (1/yr) at low cost, with a mission duration of approximately 30 days. Payload selection would be based on meritorious high-value science that can be performed by migrating sub-orbital payloads to orbit. Establishment of this capability is a essential for NASA as it strives to advance technical readiness and lower costs for risk averse Explorers and flagship missions in its pursuit of a balanced and sustainable program and achieve big science goals within a limited fiscal environment. The development of a new generation of small, low-cost launch vehicles (SLV), primarily the SpaceX Falcon 1 and the Orbital Sciences Minotaur I has made this concept conceivable. The NASA Wallops Flight Facility (WFF)conducted a detailed engineering concept study, aimed at defining the technical characteristics of all phases of a mission, from design, procurement, assembly, test, integration and mission operations. The work was led by Dr. Raymond Cruddace, a veteran of the SR program and the prime mover of the EDSR concept. The team investigated details such as, the "FAA licensed contract" for launch service procurement, with WFF and NASA SMD being responsible for mission assurance which results in a factor of two cost savings over the current approach. These and other creative solutions resulted in a proof-of-concept Class D mission design that could have a sustained launch rate of at least 1/yr, a mission duration of up to about 3 months, and a total cost of $25-30 million for each mission. The payload includes a pointing system with arc second precision, a command and data system which can be configured to meet the unique requirements of a particular mission, and a solar cell-battery power system. Anticipating the tremendous need of access to space, Cruddace and his team included a capability of inclusion of a number of smaller secondary instruments, ranging in size from CubeSats to instruments weighing up to 100 lb. These secondary payloads could be ejected as needed by P-PODs. In this talk, we will summarize EDSR, a legacy of Ray Cruddace.

  8. The Internet: How Fast Can You Download?

    ERIC Educational Resources Information Center

    Shearer, Ron

    1997-01-01

    Discusses faster modems for downloading information from the Internet that may become available through cable or telephone industries. Topics include ADSL (Asymmetric Digital Subscriber Line) modems; Direct PC--downloading satellite transmissions; Land Multichannel Distribution System (LMDS)--a wireless communication device; and Internet…

  9. Testing and performance analysis of a 650-Mbps quaternary pulse position modulation (QPPM) modem for free-space laser communications

    NASA Astrophysics Data System (ADS)

    Mortensen, Dale J.

    1995-04-01

    The testing and performance of a prototype modem developed at NASA Lewis Research Center for high-speed free-space direct detection optical communications is described. The testing was performed under laboratory conditions using computer control with specially developed test equipment that simulates free-space link conditions. The modem employs quaternary pulse position modulation at 325 Megabits per second (Mbps) on two optical channels, which are multiplexed to transmit a single 650 Mbps data stream. The measured results indicate that the receiver's automatic gain control (AGC), phased-locked-loop slot clock recovery, digital symbol clock recovery, matched filtering, and maximum likelihood data recovery circuits were found to have only 1.5 dB combined implementation loss during bit-error-rate (BER) performance measurements. Pseudo random bit sequences and real-time high quality video sources were used to supply 650 Mbps and 325 Mbps data streams to the modem. Additional testing revealed that Doppler frequency shifting can be easily tracked by the receiver, that simulated pointing errors are readily compensated for by the AGC circuits, and that channel timing skew affects the BER performance in an expected manner. Overall, the needed technologies for a high-speed laser communications modem were demonstrated.

  10. Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

    NASA Astrophysics Data System (ADS)

    Koblents, B.; Belanger, M.; Woods, D.; McLane, P. J.

    While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

  11. Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

    NASA Technical Reports Server (NTRS)

    Koblents, B.; Belanger, M.; Woods, D.; Mclane, P. J.

    1993-01-01

    While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

  12. Quantitative analysis of Ostracoda and water masses around Japan: Application to Pliocene and Pleistocene paleoceanography

    USGS Publications Warehouse

    Ikeya, Noriyuki; Cronin, Thomas M.

    1993-01-01

    An ostracode data base consisting of 273 samples from coretops and comprising 226 species was developed for the seas around the Japanese Islands to determine zoogeographic patterns and for application to Pliocene and Pleistocene paleoceanography in the area. Quantitative analyses of the 59 most common taxa between 0 and 300m water depth indicate that ostracode associations are controlled by the main oceanic water masses around Japan and that bottom water temperature is a key factor influencing species distributions. Ostracodes from the following water masses were studied: warm Kuroshio Current, Tsushima Current (Tsugaru Current and Soya Current), Japan Sea intermediate water, Japan Sea proper water and cold Oyashio Current. In order to apply the modem coretop data base to fossil ostracode assemblages, the modem analog technique (MAT) using a squared chord distance (SCD) measure of dissimilarity was tested as a means of comparing fossil and modem assemblages. SCD values of 0.25 or less adequately identify modem analogs from the coretop data set at the local ecological level (i.e. within the same modern bay), while values of 0.25-0.5 identify modem analogs at the level of the zoogeographic province. The MAT method was tested against 3 Pliocene and 11 Pleistocene formations in Japan to examine the use of the MAT in paleoceanographic reconstruction.

  13. The Installation of Satellite Modems on SEIS-UK Supported Remote Seismic Deployments

    NASA Astrophysics Data System (ADS)

    Horleston, A. C.; Brisbourne, A.; Hawthorn, D.

    2006-12-01

    SEIS-UK, as the UK's NERC funded national seismic equipment facility, is frequently involved in large, often remote, temporary seismic networks (running for up to 2 years). Up till now all these deployments have been managed solely by on-site maintenance but now SEIS-UK is investing in a number of satellite modems. The Michrosat 2400 OEM Modems, provided by Wireless Innovations Ltd, will be integrated within Guralp DCM data-logger units and will be used to provide regular state-of-health reports from remote networks. They will also provide the user the facility to communicate with the deployed systems, apply configuration changes and request system re-boots. This should lead to less instrument down-time and allow for more focussed site visits and thus, hopefully, reduce the cost (and servicing time) of remote installations. The Michrosat Modems are relatively low-powered and draw a maximum current of 2.5A (at 4.4v) for a few microseconds when initialising a call, dropping to bursts of approximately 1A when transmitting. This makes them ideally suited to temporary deployments relying on solar charged battery power. We will present examples of the configuration and typical deployment of the modems and the types of data transmitted.

  14. A Comparison of Aircraft Maintenance Organizational Structures

    DTIC Science & Technology

    1992-09-01

    Outputs ... ...................... 85 Appendix E : Double Cross-Validation ........... 117 Appendix F: Exchange of Independent Variables...splits into three major production branches (6). See Figure 8. 26 Aircraf t Interm ia•’ e Maintenance Off icerzI A ssistantAIKO I 1|A/ant a A Traiing...responsible for all aircraft maintenance activities, see Figure 9 (4:3). rdor ! E •; e Techn•1i Se~rvices Wff oE r I f .1 Bass Airaraf t Iaintenanoc E

  15. 77 FR 21996 - Certain Equipment for Communications Networks, Including Switches, Routers, Gateways, Bridges...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-778] Certain Equipment for Communications Networks, Including Switches, Routers, Gateways, Bridges, Wireless Access Points, Cable Modems, IP Phones... networks, including switches, routers, gateways, bridges, wireless access points, cable modems, IP phones...

  16. Impact of satellite aeronautical channel on modem specifications

    DOT National Transportation Integrated Search

    1974-03-01

    The report analyzes the effects of surface-scattered multipath on the performance of ranging and data modems such as might be used on the aircraft-satellite channel of an air-traffic control system. An exact analysis is carried out on the effects of ...

  17. Tracking and data system support for the Mariner Mars 1971 mission. Prelaunch phase through first trajectory correction maneuver, volume 1

    NASA Technical Reports Server (NTRS)

    Laeser, R. P.; Textor, G. P.; Kelly, L. B.; Kelly, M.

    1972-01-01

    The DSN command system provided the capability to enter commands in a computer at the deep space stations for transmission to the spacecraft. The high-rate telemetry system operated at 16,200 bits/sec. This system will permit return to DSS 14 of full-resolution television pictures from the spacecraft tape recorder, plus the other science experiment data, during the two playback periods of each Goldstone pass planned for each corresponding orbit. Other features included 4800 bits/sec modem high-speed data lines from all deep space stations to Space Flight Operations Facility (SFOF) and the Goddard Space Flight Center, as well as 50,000 bits/sec wideband data lines from DSS 14 to the SFOF, thus providing the capability for data flow of two 16,200 bits/sec high-rate telemetry data streams in real time. The TDS performed prelaunch training and testing and provided support for the Mariner Mars 1971/Mission Operations System training and testing. The facilities of the ETR, DSS 71, and stations of the MSFN provided flight support coverage at launch and during the near-earth phase. The DSSs 12, 14, 41, and 51 of the DSN provided the deep space phase support from 30 May 1971 through 4 June 1971.

  18. Programmable rate modem utilizing digital signal processing techniques

    NASA Technical Reports Server (NTRS)

    Bunya, George K.; Wallace, Robert L.

    1989-01-01

    The engineering development study to follow was written to address the need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) modulation. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. Here design tradeoffs in each portion of the modulator and demodulator subsystem are outlined, and viable circuit approaches which are easily repeatable, have low implementation losses and have low production costs are identified. The research involved for this study was divided into nine technical papers, each addressing a significant region of concern in a variable rate modem design. Trivial portions and basic support logic designs surrounding the nine major modem blocks were omitted. In brief, the nine topic areas were: (1) Transmit Data Filtering; (2) Transmit Clock Generation; (3) Carrier Synthesizer; (4) Receive AGC; (5) Receive Data Filtering; (6) RF Oscillator Phase Noise; (7) Receive Carrier Selectivity; (8) Carrier Recovery; and (9) Timing Recovery.

  19. xDSL connection monitor

    DOEpatents

    Horton, John J.

    2006-04-11

    A system and method of maintaining communication between a computer and a server, the server being in communication with the computer via xDSL service or dial-up modem service, with xDSL service being the default mode of communication, the method including sending a request to the server via xDSL service to which the server should respond and determining if a response has been received. If no response has been received, displaying on the computer a message (i) indicating that xDSL service has failed and (ii) offering to establish communication between the computer and the server via the dial-up modem, and thereafter changing the default mode of communication between the computer and the server to dial-up modem service. In a preferred embodiment, an xDSL service provider monitors dial-up modem communications and determines if the computer dialing in normally establishes communication with the server via xDSL service. The xDSL service provider can thus quickly and easily detect xDSL failures.

  20. Effects of electromagnetic waves emitted from 3G+wi-fi modems on human semen analysis.

    PubMed

    Kamali, Koosha; Atarod, Mohammadmehdi; Sarhadi, Saeedeh; Nikbakht, Javad; Emami, Maryam; Maghsoudi, Robab; Salimi, Hormoz; Fallahpour, Bita; Kamali, Negar; Momtazan, Abdolreza; Ameli, Mojtaba

    2017-10-25

    The purpose of this study was to evaluate the effects of 3G+wifi modems on human sperm quality.A total of 40 semen specimens were gathered between March and September 2015, from healthy adult men. The sperm samples were divided into two groups - 3G+wi-fi exposed and unexposed groups. In the unexposed group, the specimens were shielded by aluminum foil in three layers and put into an incubator at a temperature of 37°C for 50 minutes. The exposed group was positioned in another room in an incubator at a temperature of 37°C for 50 minutes. A 3G+wi-fi modem was put into the same incubator and a laptop computer was connected to the modem and was downloading for the entire 50 minutes.Semen analysis was done for each specimen and comparisons between parameters of the two groups were done by using Kolmogorov-Smirnov study and a paired t-test. Mean percentage of sperm with class A and B motility were not significantly different in two groups (p = 0.22 and 0.54, respectively). In class C, it was significantly lower in the exposed group (p = 0.046), while in class D it was significantly higher (p = 0.022).Velocity curvilinear, velocity straight line, velocity average path, mean angular displacement, lateral displacement and beat cross frequency were significantly higher in the unexposed group. The limitation was the in vitro design. Electromagnetic waves (EMWs) emitted from 3G+wi-fi modems cause a significant decrease in sperm motility and velocity, especially in non-progressive motile sperms. Other parameters of semen analysis did not change significantly.EMWs, which are used in communications worldwide, are a suspected cause of male infertility. Many studies evaluated the effects of cell phones and wi-fi on fertility. To our knowledge, no study has yet been done to show the effects of EMWs emitted from 3G+wi-fi modems on fertility.Our study revealed a significant decrease in the quality of human semen after exposure to EMWs emitted from 3G+wi-fi modems.

  1. The changing nature of spacecraft operations: From the Vikings of the 1970's to the great observatories of the 1990's and beyond

    NASA Technical Reports Server (NTRS)

    Ledbetter, Kenneth W.

    1992-01-01

    Four trends in spacecraft flight operations are discussed which will reduce overall program costs. These trends are the use of high-speed, highly reliable data communications systems for distributing operations functions to more convenient and cost-effective sites; the improved capability for remote operation of sensors; a continued rapid increase in memory and processing speed of flight qualified computer chips; and increasingly capable ground-based hardware and software systems, notably those augmented by artificial intelligence functions. Changes reflected by these trends are reviewed starting from the NASA Viking missions of the early 70s, when mission control was conducted at one location using expensive and cumbersome mainframe computers and communications equipment. In the 1980s, powerful desktop computers and modems enabled the Magellan project team to operate the spacecraft remotely. In the 1990s, the Hubble Space Telescope project uses multiple color screens and automated sequencing software on small computers. Given a projection of current capabilities, future control centers will be even more cost-effective.

  2. [Japanese who affected modern medicine in Taiwan: obstetrics and gynecology].

    PubMed

    Wang, Ming-Tung

    2009-12-01

    This text describes the leaders who established the modem obstetrics and gynecology for Taiwan. during the Japan-colonizing period (1895-1945). These leaders are Mr. Kawasoye, M., Mr. Mukae K., and Mr. Magara M. The lives of these leaders were different, but they all strongly contributed to the development of modem obstetrics and gynecology in Taiwan. With regard to the passage of time, Mr. Kawasoye contributed the initial efforts, Mr. Mukae worked during the flourishing period of the clinic; and Mr. Magara worked during the mature period, emphasizing research. These three periods are closely correlated with the course of the development of modem obstetrics and gynecology in Taiwan.

  3. Real-time sensing of lint quality

    USDA-ARS?s Scientific Manuscript database

    Modem cotton gins have the purpose of extracting lint (the cotton) from trash and seeds- usually the sticks, leaves and burrs that are entrained with the cotton. These modem gins include many individual machine components that are operated sequentially to form the gin processing line. Recent on-line...

  4. The effect of three culture methods on intensive culture system of pacific white shrimp ( Litopenaeus vannamei)

    NASA Astrophysics Data System (ADS)

    Ma, Zhen; Wan, Rong; Song, Xiefa; Gao, Lei

    2013-09-01

    Different culture methods may affect the intensive culture system of Pacific white shrimp ( Litopenaeus vannamei) regarding water quality and growth and economic performance. This study evaluated the potential effects of three culture methods through cultivation of juvenile shrimps under consistent tank management conditions for 84 d. The three methods involved shrimp cultivation in different tanks, i.e., outdoor tanks with cement bottom (mode-C), greenhouse tanks with cement bottom (mode-G) and outdoor tanks with mud-substrate (mode-M). Results showed that water temperature was significantly higher in mode-G than that in mode-C ( P < 0.05). In contrast to the other two treatments, mode-M had stable pH after 50 d cultivation of shrimps. In the mid-late period, the average concentrations of TAN, NO2-N, DIP and COD were significantly lower in mode-M and mode-G compared with those in mode-C ( P < 0.05). Despite lack of differences in the final shrimp weight among different treatments ( P > 0.05), mode-M had significantly higher shrimp yield, survival rate and feed conversion rate ( P < 0.05) than other modes. There were significant differences in revenue and net return among different treatments ( P < 0.05). These demonstrated that the treatments of mode-G and mode-M were conductive to the intensive culture system of L. vannamei.

  5. ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) Payload

    NASA Technical Reports Server (NTRS)

    Seas, Antonios; Gonnsen, Zachary; Yarnall, Timothy

    2018-01-01

    Presentation on ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) Payload at the Japanese Experiment Module (JEM) External Payload Interface Coordination Meeting on May 9, 2018 at the Japan Aerospace Exploration Agency (JAXA) in Tsukuba, Japan. Meeting to discuss details of installing payload on JEM.

  6. A Study of Computer-Modem Students: A Call for Action.

    ERIC Educational Resources Information Center

    Richards, Irving; And Others

    Offering participation in courses via modem can benefit both colleges, which are often coping with downsizing or insufficient classroom space, and students, who may face prohibitive work schedules, a need to remain at home, physical handicaps, or incarceration. This study assembles demographic information on higher education students who…

  7. Office Automation and the Navy Finance Center.

    DTIC Science & Technology

    1984-09-01

    inexpensive premise-distribution cable. - r wide range o protocols and transmission speeds. - Modem -pooling. Modems can be accessed on an as-needeo...the IBM System Nerworr Architecture (SNA and is composed of four 56K baud ii ne [Ref. IT]. 4. Protocop L ers NFC has Kodak and Royal copiers

  8. Simple Refractometers for Index Measurements by Minimum Deviation Method from Far-ultraviolet to Near Infrared

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.; Madison, Timothy J.; Petrone, Peter

    1998-01-01

    The focal shift of an optical filter used in non-collimated light depends directly on substrate thickness and index of refraction. The HST Advanced Camera for Surveys (ACS) requires a set of filters whose focal shifts are tightly matched. Knowing the index of refraction for substrate glasses allows precise substrate thicknesses to be specified. Two refractometers have been developed at the Goddard Space Flight Center (GSFC) to determine the indices of refraction of materials from which ACS filters are made. Modem imaging detectors for the near infrared, visible, and far ultraviolet spectral regions make these simple yet sophisticated refractometers possible. A new technology, high accuracy, angular encoder also developed at GSFC makes high precision index measurement possible in the vacuum ultraviolet.

  9. Iridium: Global OTH data communications for high altitude scientific ballooning

    NASA Astrophysics Data System (ADS)

    Denney, A.

    While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

  10. Performance of a Q-M/PSK Data Modem Operating in a Voice and Data Mode Through the ATS-6 Satellite

    DOT National Transportation Integrated Search

    1979-02-01

    Experiments were conducted in cooperation with the Communications Research Center (CRC) of Canada to gather additional performance data on the error statistics of the digital data channel of the Q-M/PSK Voice and Data Modem, while operating in the hy...

  11. Flight Crew Sleep in Long-Haul Aircraft Bunk Facilities: Survey Results

    NASA Technical Reports Server (NTRS)

    Rosekind, Mark R.; Miller, Donna L.; Gregory, Kevin B.; Dinges, David F.; Shafto, Michael G. (Technical Monitor)

    1995-01-01

    Modem long-haul aircraft can fly up to 16 continuous hours and provide a 24-hour, global capability. Extra (augmented) flight crew are available on long flights to allow planned rest periods, on a rotating basis, away from the flight deck in onboard crew rest facilities (2 bunks). A NASA/FAA study is under-way to examine the quantity and quality of sleep obtained in long-haul aircraft bunks and the factors that promote or interfere with that sleep. The first phase of the study involved a retrospective survey, followed by a second phase field study to collect standard polysomnographic data during inflight bunk sleep periods. A summary of the Phase I survey results are reported here. A multi-part 54-question retrospective survey was completed by 1,404 flight crew (37% return rate) at three different major US air carriers flying B747-100, 200, 400, and MD- 11 long-haul aircraft. The questions examined demographics, quantity and quality of sleep at home and in onboard bunks, factors that promote or interfere with sleep, and effects on subsequent performance and alertness. Flight crew reported a mean bunk sleep latency of 39.4 mins (SD=28.3 mins) (n=1,276) and a mean total sleep time of 2.2 hrs (SD=1.3 hrs) (n=603). (Different flight lengths could affect overall time available for sleep.) Crew rated 25 factors for their interference or promotion of bunk sleep. Figure I portrays the average ratings for each factor across all three carriers. A principal components analysis of the 25 factors revealed three areas that promoted bunk sleep: physiological (e.g., readiness for sleep), physical environment (e.g., bunk size, privacy), and personal comfort (e.g., blankets, pillows). Five areas were identified that interfered with sleep: environmental disturbance (e.g., background noise, turbulence), luminosity (e.g., lighting), personal disturbances (e.g., bathroom trips, random thoughts), environmental discomfort (e.g., low humidity, cold), and interpersonal disturbances (e.g., bunk partner).

  12. Development of High Data Rate Acoustic Multiple-Input/Multiple-Output Modems

    DTIC Science & Technology

    2015-09-30

    communication capabilities of underwater platforms and facilitate real-time adaptive operations in the ocean. OBJECTIVES The ...signaling at the transmitter and low-complexity time reversal processing at the receiver. APPROACH Underwater acoustic (UWA) communication is useful...digital communications in shallow water environments. The advancement has direct impacts on defense appliations since underwater acoustic modems

  13. An OKQPSK modem incorporating numerically controlled carrier synthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Oetken, R.E.

    1988-04-04

    The feasibility of incorporating numerically controlled oscillators (NCO) in communication related applications is evaluated. NCO generation of sinusoids may prove useful in systems requiring precise frequency control, tuning linearity, and orthogonality versus frequency. An OKQPSK modem operating at a data rate of 200 kb/s was fabricated. The modem operates in a back to back hardwired channel and thus does not incorporate carrier or symbol timing recovery. Spectra of the NCO generated sinusoids are presented along with waveforms from the modulation and demodulation process. Generation of sinusoids in the digital domain is a viable alternative to analog oscillators. Implementation of anmore » NCO should be considered when frequency allocation, tuning bandwidth, or frequency hopped transmission requires precise frequency synthesis. 24 figs.« less

  14. Multicriteria Gain Tuning for Rotorcraft Flight Controls (also entitled The Development of the Conduit Advanced Control System Design and Evaluation Interface with a Case Study Application Fly by Wire Helicopter Design)

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel

    1997-01-01

    Handling qualities analysis and control law design would seem to be naturally complimenting components of aircraft flight control system design, however these two closely coupled disciplines are often not well integrated in practice. Handling qualities engineers and control system engineers may work in separate groups within an aircraft company. Flight control system engineers and handling quality specialists may come from different backgrounds and schooling and are often not aware of the other group's research. Thus while the handling qualities specifications represent desired aircraft response characteristics, these are rarely incorporated directly in the control system design process. Instead modem control system design techniques are based on servo-loop robustness specifications, and simple representations of the desired control response. Comprehensive handling qualities analysis is often left until the end of the design cycle and performed as a check of the completed design for satisfactory performance. This can lead to costly redesign or less than satisfactory aircraft handling qualities when the flight testing phase is reached. The desire to integrate the fields of handling qualities and flight,control systems led to the development of the CONDUIT system. This tool facilitates control system designs that achieve desired handling quality requirements and servo-loop specifications in a single design process. With CONDUIT, the control system engineer is now able to directly design and control systems to meet the complete handling specifications. CONDUIT allows the designer to retain a preferred control law structure, but then tunes the system parameters to meet the handling quality requirements.

  15. Sounding of the Ion Energization Region: Resolving Ambiguities

    NASA Technical Reports Server (NTRS)

    LaBelle, James

    2003-01-01

    Dartmouth College provided a single-channel high-frequency wave receiver to the Sounding of the Ion Energization Region: Resolving Ambiguities (SIERRA) rocket experiment launched from Poker Flat, Alaska, in January 2002. The receiver used signals from booms, probes, preamplifiers, and differential amplifiers provided by Cornell University coinvestigators. Output was to a dedicated 5 MHz telemetry link provided by WFF, with a small amount of additional Pulse Code Modulation (PCM) telemetry required for the receiver gain information. We also performed preliminary analysis of the data. The work completed is outlined below, in chronological order.

  16. Modem Characterization Through a Wideband, Hard-Limited Ka-Band Satellite Channel

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.; Ivancic, William; Tanger, Tom; Cronon, Chris; Lee, Donald; Kifer, David R.

    1999-01-01

    NASA is using a commercial customized TDMA/FDMA bandwidth on demand modem for use with the Advanced Communications Technology Satellite (ACTS) to highlight the numerous services and experiments that can be performed using small Ka-Band terminals. Characterizing the modems proved challenging due to the characteristics of the satellite transponder. The ACTS channel is hard-limited and up to 900 MHz wide. The channel has some unusual dynamic properties due to the satellite and antenna system, which make modem testing through the satellite challenging and the test requirements stringent. The satellite Multi-Beam Antenna (MBA) has a 1 hertz oscillation induced by the momentum wheel, which causes the transmit antenna pattern to move slightly. This results in a 1 hertz oscillation in the ground station receive power, with amplitude changes up to 1 dB depending on terminal location within a spot beam and associated gain slope. In addition, ACTS experiences a solar induced "thermal event" each day. This "thermal event" occurs when the sun heats the antenna support structure causing the transmit and receive reflectors to mispoint. This results in a slowly decreasing or increasing power density at the ground station receiver as the antenna pattern moves off bore-site. This paper describes the method used to fully characterize the TDMA/FDMA modem through the ACTS wideband, hard-limited transponder. In particular, techniques are discussed for conducting RF measurements on such a channel, the affect that the thermal characteristics and 1 hertz variations have on the accuracy of the results, and suggested means to minimize the error and provide useful and valuable data.

  17. Digital Troposcatter Performance Model. Users Manual.

    DTIC Science & Technology

    1983-11-01

    and Information Systems - .,- - - UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) S REPORT DOCUIAENTATION PAGE READ...Diffraction Multipath Prediction MD-918 Modem Error Rate Prediction AN/TRC-170 Link Analysis 20. ABSTRACT (Continue en reverse esie If neceseay end...configurations used in the Defense Communications System (DCS), and prediction of the performance of both the MD-918 and AN/TRC-170 digital troposcatter modems

  18. [Modern concepts of trauma care and multiple trauma management in oral and maxillofacial region].

    PubMed

    Tan, Yinghui

    2015-06-01

    Multiple trauma management requires the application of modem trauma care theories. Optimal treatment results can be achieved by reinforcing cooperation and stipulating a treatment plan together with other disciplines. Based on modem theories in trauma care and our understanding of the theoretical points, this paper analyzes the injury assessment strategies and methods in oral and maxillofacial multiple trauma management. Moreover, this paper discusses operating time and other influencing factors as well as proposed definitive surgical timing and indications in comprehensive management of oral and maxillofacial multiple trauma patients associated with injuries in other body parts. We hope that this paper can help stomatological physicians deepen their understanding of modem trauma care theories and improve their capacity and results in the treatment of oral and maxillofacial multiple trauma.

  19. Design of an anti-Rician-fading modem for mobile satellite communication systems

    NASA Technical Reports Server (NTRS)

    Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

    1995-01-01

    To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

  20. High data rate modem simulation for the space station multiple-access communications system

    NASA Technical Reports Server (NTRS)

    Horan, Stephen

    1987-01-01

    The communications system for the space station will require a space based multiple access component to provide communications between the space based program elements and the station. A study was undertaken to investigate two of the concerns of this multiple access system, namely, the issues related to the frequency spectrum utilization and the possibilities for higher order (than QPSK) modulation schemes for use in possible modulators and demodulators (modems). As a result of the investigation, many key questions about the frequency spectrum utilization were raised. At this point, frequency spectrum utilization is seen as an area requiring further work. Simulations were conducted using a computer aided communications system design package to provide a straw man modem structure to be used for both QPSK and 8-PSK channels.

  1. Optimal Power Allocation for Downstream xDSL With Per-Modem Total Power Constraints: Broadcast Channel Optimal Spectrum Balancing (BC-OSB)

    NASA Astrophysics Data System (ADS)

    Le Nir, Vincent; Moonen, Marc; Verlinden, Jan; Guenach, Mamoun

    2009-02-01

    Recently, the duality between Multiple Input Multiple Output (MIMO) Multiple Access Channels (MAC) and MIMO Broadcast Channels (BC) has been established under a total power constraint. The same set of rates for MAC can be achieved in BC exploiting the MAC-BC duality formulas while preserving the total power constraint. In this paper, we describe the BC optimal power allo- cation applying this duality in a downstream x-Digital Subscriber Lines (xDSL) context under a total power constraint for all modems over all tones. Then, a new algorithm called BC-Optimal Spectrum Balancing (BC-OSB) is devised for a more realistic power allocation under per-modem total power constraints. The capacity region of the primal BC problem under per-modem total power constraints is found by the dual optimization problem for the BC under per-modem total power constraints which can be rewritten as a dual optimization problem in the MAC by means of a precoder matrix based on the Lagrange multipliers. We show that the duality gap between the two problems is zero. The multi-user power allocation problem has been solved for interference channels and MAC using the OSB algorithm. In this paper we solve the problem of multi-user power allocation for the BC case using the OSB algorithm as well and we derive a computational efficient algorithm that will be referred to as BC-OSB. Simulation results are provided for two VDSL2 scenarios: the first one with Differential-Mode (DM) transmission only and the second one with both DM and Phantom- Mode (PM) transmissions.

  2. PV-Diesel Hybrid SCADA Experiment Network Design

    NASA Technical Reports Server (NTRS)

    Kalu, Alex; Durand, S.; Emrich, Carol; Ventre, G.; Wilson, W.; Acosta, R.

    1999-01-01

    The essential features of an experimental network for renewable power system satellite based supervisory, control and data acquisition (SCADA) are communication links, controllers, diagnostic equipment and a hybrid power system. Required components for implementing the network consist of two satellite ground stations, to satellite modems, two 486 PCs, two telephone receivers, two telephone modems, two analog telephone lines, one digital telephone line, a hybrid-power system equipped with controller and a satellite spacecraft. In the technology verification experiment (TVE) conducted by Savannah State University and Florida Solar Energy Center, the renewable energy hybrid system is the Apex-1000 Mini-Hybrid which is equipped with NGC3188 for user interface and remote control and the NGC2010 for monitoring and basic control tasks. This power system is connected to a satellite modem via a smart interface, RS232. Commands are sent to the power system control unit through a control PC designed as PC1. PC1 is thus connected to a satellite model through RS232. A second PC, designated PC2, the diagnostic PC is connected to both satellite modems via separate analog telephone lines for checking modems'health. PC2 is also connected to PC1 via a telephone line. Due to the unavailability of a second ground station for the ACTS, one ground station is used to serve both the sending and receiving functions in this experiment. Signal is sent from the control PC to the Hybrid system at a frequency f(sub 1), different from f(sub 2), the signal from the hybrid system to the control PC. f(sub l) and f(sub 2) are sufficiently separated to avoid interference.

  3. [Analysis of supplying situation in pharmacies. I. Supply with medicaments and health appliances from the viewpoint of pharmacies and distributors].

    PubMed

    Macesková, B; Vyhnalíková, J

    2007-01-01

    The paper describes the contemporary methods of ordering, their demands for time, and positive and negative aspects. The results of the analysis of the data from pharmacies were compared with the data found by analyzing the data provided by the distributor. The methodology of the paper includes: a questionnaire survey, the method of the autopicture, and an analysis of archival data from pharmacies and distributors. The most frequent response to the question concerning the number of supplying wholesale distributors is two (38.1% of pharmacies) and three (33.3 % of pharmacies); pharmacies receive supplies from them most frequently three times a day (28.1% of pharmacies). 61.9 % of pharmacies compile the orders intuitively, 38.1% of them use the possibilities of the automatic proposal of the order using a PC system. 66.6% of pharmacies utilize modem ordering whose advantages are rapidity (493%), time availability (41.2%), a list of confirmed preparations (28.5 %), and financial advantageousness (23.8 %). The average time of ordering amounts to 21 min a day for telephone orders and 4 min a day for modem orders, the average proportion in the use of the individual methods of ordering is 59.1% to 40.9% of items to the benefit of modem orders. A concrete pharmacy was selected to demonstrate the effect of changes resulting from the transition from exclusively telephonic ordering to prevalently modem ordering; saved time period amounted to 62.5 % (from 14.4 s to 5.4 s per 1 ordered item). The analysis of distributors' data reveals an increase in the share of the items and packages ordered via modem (from 22.2%, and 20.6%, respectively, in the year 2000, to 54.5% and 49.8%, respectively, in the year 2004).

  4. NASA. Lewis Research Center Advanced Modulation and Coding Project: Introduction and overview

    NASA Technical Reports Server (NTRS)

    Budinger, James M.

    1992-01-01

    The Advanced Modulation and Coding Project at LeRC is sponsored by the Office of Space Science and Applications, Communications Division, Code EC, at NASA Headquarters and conducted by the Digital Systems Technology Branch of the Space Electronics Division. Advanced Modulation and Coding is one of three focused technology development projects within the branch's overall Processing and Switching Program. The program consists of industry contracts for developing proof-of-concept (POC) and demonstration model hardware, university grants for analyzing advanced techniques, and in-house integration and testing of performance verification and systems evaluation. The Advanced Modulation and Coding Project is broken into five elements: (1) bandwidth- and power-efficient modems; (2) high-speed codecs; (3) digital modems; (4) multichannel demodulators; and (5) very high-data-rate modems. At least one contract and one grant were awarded for each element.

  5. Low-Power Direct-Sequence Spread-Spectrum Modem Architecture for Distributed Wireless Sensor Networks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chien, C; Elgorriaga, I; McConaghy, C

    2001-07-03

    Emerging CMOS and MEMS technologies enable the implementation of a large number of wireless distributed microsensors that can be easily and rapidly deployed to form highly redundant, self-configuring, and ad hoc sensor networks. To facilitate ease of deployment, these sensors should operate on battery for extended periods of time. A particular challenge in maintaining extended battery lifetime lies in achieving communications with low power. This paper presents a direct-sequence spread-spectrum modem architecture that provides robust communications for wireless sensor networks while dissipating very low power. The modem architecture has been verified in an FPGA implementation that dissipates only 33 mWmore » for both transmission and reception. The implementation can be easily mapped to an ASIC technology, with an estimated power performance of less than 1 mW.« less

  6. The United States Army 1995 Modernization Plan. Force 21

    DTIC Science & Technology

    1995-04-06

    being modified to support the requirements and new dangers of our changing times. It is often said that we study history so as not to repeat thu...intuitive sense of battle gained from study and expertise. Training remains the key to modem, combat-ready Light Forces. Effective modemization and...Devices, Simulators and Simulations (TADSS) Light Forces training is supported by the Combined Arms Training Strategy (CATS). CATS is a descriptive

  7. Programmable rate modem utilizing digital signal processing techniques

    NASA Technical Reports Server (NTRS)

    Naveh, Arad

    1992-01-01

    The need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK) modulation is discussed. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. The design trade-offs in each portion of the modulator and demodulator subsystem are outlined.

  8. Automated Air Information Production System - Phase II.

    DTIC Science & Technology

    1980-10-01

    Alphanumeric CRT terminals, 2 Gandalf Data Inc. Model LDS 250/3 56 Kbps synchronous short haul modems , 2 General Data Comm Industries TDM-1205 time...supplied encrypt/decrypt devices which would interface to the communications multiplexers supplied by Synectics. Synectics also supplied short haul modems ...During the development effort and throughput of the T&E period the high speed ( 56K bps) link would intermittently go out of synchronization. The problem

  9. Demonstration of Multi-Gbps Data Rates at Ka-Band Using Software-Defined Modem and Broadband High Power Amplifier for Space Communications

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.; Landon, David G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen; McIntire, William K.; Metz, John L.; Smith, Francis J.

    2011-01-01

    The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 W and efficiency greater than 60 percent. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10(exp -9). The presented results include a plot of the received waveform constellation, BER vs. E(sub b)/N(sub 0) and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA s payload data rate can be increased by at least an order of magnitude (greater than 10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.

  10. Balloon Program Wraps up in Antarctica, Heading to New Zealand

    NASA Image and Video Library

    2015-02-02

    Caption: A NASA Super Pressure Balloon with the COSI payload is ready for launch from McMurdo, Antarctica. Credit: NASA More info: NASA’s globetrotting Balloon Program Office is wrapping up its 2014-2015 Antarctic campaign while prepping for an around-the-world flight launching out of Wanaka, New Zealand, in March. After 16 days, 12 hours, and 56 minutes of flight, operators successfully conducted a planned flight termination of the Suborbital Polarimeter for Inflation Dust and the Epoch of Reionization (SPIDER) mission Saturday, Jan. 18, the final mission of the campaign. Other flights in the 2014-2015 Antarctic campaign included the Antarctic Impulsive Transient Antenna (ANITA-III) mission as well as the Compton Spectrometer and Imager (COSI) payload flown on the developmental Super Pressure Balloon (SPB). ANITA-III successfully wrapped up Jan. 9 after 22 days, 9 hours, and 14 minutes of flight. Flight controllers terminated the COSI flight 43 hours into the mission after detecting a small gas leak in the balloon. Crews are now working to recover all three instruments from different locations across the continent. The 6,480-pound SPIDER payload is stationary at a position about 290 miles from the United Kingdom’s Sky Blu Logistics Facility in Antarctica. The 4,601 pound ANITA-III payload, located about 100 miles from Australia’s Davis Station, and the 2,866 pound COSI payload, located about 340 miles from the United States McMurdo Station both had numerous key components recovered in the past few days. Beginning in late January, the Balloon Program Office will deploy a team to Wanaka, New Zealand, to begin preparations for an SPB flight, scheduled to launch in March. The Program Office seeks to fly the SPB more than 100 days, which would shatter the current flight duration record of 55 days, 1 hour, and 34 minutes for a large scientific balloon. “We’re looking forward to the New Zealand campaign and hopefully a history-making flight with the Super Pressure Balloon,” said Debbie Fairbrother, NASA’s Balloon Program Office Chief. Most scientific balloons see altitude variances based on temperature changes in the atmosphere at night and during the day. The SPB is capable of missions on the order of 100 days or more at constant float altitudes due to the pressurization of the balloon. “Stable, long-duration flights at near-space altitudes above more than 99 percent of the atmosphere are highly desirable in the science community, and we’re ready to deliver,” said Fairbrother. In addition to the SPB flight in March, the Balloon Program Office has 10 more balloon missions planned through September 2015 to include scheduled test flights of the Low-Density Supersonic Decelerator, which is testing new technologies for landing larger, heavier payloads on Mars. NASA’s Wallops Flight Facility manages the agency’s Scientific Balloon Program with 10 to 15 flights each year from launch sites worldwide. The balloons are massive in volume; the average-sized balloon could hold the volume of nearly 200 blimps. Previous work on balloons have contributed to confirming the Big Bang Theory. For more information on NASA’s Scientific Balloon Program, see: sites.wff.nasa.gov/code820/index.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  11. Application of smart materials for improved flight performance of military aircraft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kudva, J.; Appa, K.; Martin, C.

    1995-12-31

    This paper discusses on-going work under an ARPA/WL contract to Northrop Grumman entitled {open_quotes}Smart Structures and Materials Development - Smart Wing.{close_quotes} The contract addresses the application of smart materials and smart Structures concepts to enhance the aerodynamic and maneuver performance of military aircraft. Various concepts for adaptive wing and control surfaces are being studied. Specifically, (a) wing span-wise twist control using built-in shape- memory alloy torquing mechanism and (b) cambered leading edge and trailing edge control surfaces using hybrid piezoelectric and SMA actuation, are being evaluated for a 20% model of a modem day fighter aircraft. The potential benefits ofmore » the designs include increased lift for short take-offs, improved high-speed maneuverability, and enhanced control surface effectiveness. These benefits will be quantified by testing the sub-scale model in a transonic wind tunnel next year.« less

  12. DISCOVER AQ Research Plane Arrives

    NASA Image and Video Library

    2011-06-28

    WFF Pilots Mike Singer, left, and Shane Dover stand in front of the 117-foot P-3B NASA research aircraft on the tarmac at Baltimore/Washington International Thurgood Marshall Airport, Tuesday, June 28, 2011, in Baltimore, Md. The aircraft is part of a month-long field campaign designed to improve satellite measurements of air pollution. The name of the experiment -- Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER -- AQ) -- is a mouthful, but its purpose is simple. Come July, the aircraft will be flying spirals over six ground stations in Maryland. Photo Credit: (NASA/Paul E. Alers)

  13. Low Resolution Picture Transmission (LRPT) Demonstration System

    NASA Technical Reports Server (NTRS)

    Fong, Wai; Yeh, Pen-Shu; Sank, Victor; Nyugen, Xuan; Xia, Wei; Duran, Steve; Day, John H. (Technical Monitor)

    2002-01-01

    Low-Resolution Picture Transmission (LRPT) is a proposed standard for direct broadcast transmission of satellite weather images. This standard is a joint effort by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and the National Oceanic Atmospheric Administration (NOAA). As a digital transmission scheme, its purpose is to replace the current analog Automatic Picture Transmission (APT) system for use in the Meteorological Operational (METOP) satellites. Goddard Space Flight Center has been tasked to build an LRPT Demonstration System (LDS). It's main objective is to develop or demonstrate the feasibility of a low-cost receiver utilizing a Personal Computer (PC) as the primary processing component and determine the performance of the protocol in the simulated Radio Frequency (RF) environment. The approach would consist of two phases. In the phase 1, a Commercial-off-the-Shelf (COTS) Modulator-Demodulator (MODEM) board that would perform RF demodulation would be purchased allowing the Central Processing Unit (CPU) to perform the Consultative Committee for Space Data Systems (CCSDS) protocol processing. Also since the weather images are compressed the PC would perform the decompression. Phase 1 was successfully demonstrated on December 1997. Phase 2 consists of developing a high-fidelity receiver, transmitter and environment simulator. Its goal is to find out how the METOP Specification performs in a simulated noise environment in a cost-effective receiver. The approach would be to produce a receiver using as much software as possible to perform front-end processing to take advantage of the latest high-speed PCs. Thus the COTS MODEM used in Phase 1 is performing RF demodulation along with data acquisition providing data to the receiving software. Also, environment simulator is produced using the noise patterns generated by Institute for Telecommunications Sciences (ITS) from their noise environment study.

  14. Blue Flag Distributed Wargaming System

    DTIC Science & Technology

    1992-07-01

    combat simulation , and multi- site video teleconferencing (VTC). The Warrior Flag 90 feasibility demonstration was sponsored by the 4441st Tactical...provide RS-422 cross patching, loop -back and test points. At the hub six CSUs and two fiber optic modems were cabled in the normal-thru configuration...spare crypto or the fiber optic modem may be placed on-line via a patch. Loop plugs were provided for testing. Clock switches were provided to switch

  15. Coherent Path Beamformer Front End for High Performance Acoustic Modems

    DTIC Science & Technology

    1999-09-30

    transmission underwater. This knowledge will be used to develop a test model for evaluating under water acoustic modem and other shallow water sonar ...rates can be achieved, as shown in the following two sections. WORK COMPLETED Two systems have been developed in the Sonar Laboratory of Ocean...2) More performant variable gain preamplifiers have been installed and the software updated for a better control of the dynamic range. 3) An

  16. DDN (Defense Data Network) Protocol Implementations and Vendors Guide,

    DTIC Science & Technology

    1988-02-01

    TELNET) TCP/IP on an ethernet network. The program simulates a Hayes modem through the serial port. BWFTP is a thorough implementation of the FTP...25 IMP interface at VV from 19.2 Kbps to 56K bps. The IP, ICMP, TCP, Telnet. FFP and SMTP protocols are implemented along with R-Utxities...WANs. microcomputers, dataswitches. minicomputers. "black boxes" and modems . DOCUMENTATION: Software System Overview, Generic X.25 Porting Guide

  17. Distributed Sensor Systems and Electromechanical Analog Facility

    DTIC Science & Technology

    1980-01-01

    interfaces (parallel I/O, modems , etc.) real time operating systems (perhaps a short survey of what is available in the industry today), data...consists of a LSI-11 microprocessor, 56K bytes of memory, and serial and parallel I/O boards. 2.1.7 Disk controller The standard disk controller...with MTS via the modems connected to the LSI-lls. This pseudodevice cannot be reassigned. OSWIT I/O AND INTERRUPT STRUCTURE 137 OSWIT

  18. Performance evaluation of a mobile satellite system modem using an ALE method

    NASA Technical Reports Server (NTRS)

    Ohsawa, Tomoki; Iwasaki, Motoya

    1990-01-01

    Experimental performance of a newly designed demodulation concept is presented. This concept applies an Adaptive Line Enhancer (ALE) to a carrier recovery circuit, which makes pull-in time significantly shorter in noisy and large carrier offset conditions. This new demodulation concept was actually developed as an INMARSAT standard-C modem, and was evaluated. On a performance evaluation, 50 symbol pull-in time is confirmed under 4 dB Eb/No condition.

  19. Age of ground water in basalt aquifers near Spring Creek National Fish Hatchery, Skamania County, Washington

    USGS Publications Warehouse

    Hinkle, Stephen R.

    1996-01-01

    A comparison of CFC data with both adjusted and unadjusted 14C data suggests that water discharging at the hatchery springs contains a mixture of modem and old water, where old water is defined as water recharged prior to 1944. The CFC data support a component of modem water, whereas the 14C data suggest a component of old water. Similar results were obtained from a comparison of CFC data with adjusted and unadjusted 14C data for water collected from Well 3. Well 3 is north of the hatchery springs, on a flow path that appears to be parallel to and similar in length to the flow path leading to the hatchery springs. Water from the Hatchery Well, however, may be devoid of modem water and appears to have an overall age on the order of thousands of years.

  20. A Powerful Antidote, a Strange Camel and Turkish Pepper: Iberian Science, the Discovery of the New World and the Early Modem Czech Lands.

    PubMed

    Cerna, Jana

    2016-08-01

    This article analyses the reception of knowledge about new world nature, and, more specifically, the reception of Iberian scientific knowledge of nature in the Americas, in the early modem Czech lands. It shows how the process of the reception of information about nature in the new world differed among the urban classes, intellectuals and the nobility; particular attention is paid to herbals, cosmographical works and travel reports. On the one hand, the study reveals that the efforts of Central European intellectuals to interpret new world nature were limited by the lack of necessary data and experience, which led to some misinterpretations and simplifications. On the other hand, it shows these Central European scholars to be fully-fledged members of an information network, whose works share many of the same characteristics as Iberian and, in general, early modem European science.

  1. Apparatus for fixing latency

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, David R; Bartholomew, David B; Moon, Justin

    2009-09-08

    An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region,more » the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.« less

  2. An Overview of the Guided Parafoil System Derived from X-38 Experience

    NASA Technical Reports Server (NTRS)

    Stein, Jenny M.; Madsen, Chris M.; Strahan, Alan L.

    2005-01-01

    The NASA Johnson Space Center built a 4200 sq ft parafoil for the U.S. Army Natick Soldier Center to demonstrate autonomous flight using a guided parafoil system to deliver 10,000 lbs of useable payload. The parafoil's design was based upon that developed during the X-38 program. The drop test payload consisted of a standard 20-foot Type V airdrop platform, a standard 12-foot weight tub, a 60 ft drogue parachute, a 4200 ft2 parafoil, an instrumentation system, and a Guidance, Navigation, and Control (GN&C) system. Instrumentation installed on the load was used to gather data to validate simulation models and preflight loads predictions and to perform post flight trajectory and performance reconstructions. The GN&C system, developed during NASA's X-38 program, consisted of a flight computer, modems for uplink commands and downlink data, a compass, laser altimeter, and two winches. The winches were used to steer the parafoil and to perform the dynamic flare maneuver for a soft landing. The laser was used to initiate the flare. The GN&C software was originally provided to NASA by the European Space Agency. NASA incorporated further software refinements based upon the X-38 flight test results. Three full-scale drop tests were conducted, with the third being performed during the Precision Airdrop Technology Conference and Demonstration (PATCAD) Conference at the U.S. Army Yuma Proving Ground (YPG) in November of 2003. For the PATCAD demonstration, the parafoil and GN&C software and hardware performed well, concluding with a good flare and the smallest miss distance ever experienced in NASA's parafoil drop test program. This paper describes the 4200 sq ft parafoil system, simulation results, and the results of the drop tests.

  3. NORDA’s Pattern Analysis Laboratory: Current Contributions to Naval Mapping, Charting, and Geodesy

    DTIC Science & Technology

    1989-04-01

    magnetic observatories (McLeod, 1988). Using system integrates a suite of sensors and control devices the PAL’s VAX 11/780, spherical harmonic models to...DJAO:[FPS]*.OLB 5. Miscellaneous Utilities CALENDAR (NORDA events) 780 $ CALENDAR (menu-driven) DIALER modem controller 780 $ R AUTO DIAL:DIALER DTC...Utilities CALENDAR (NORDA events) 780 CALENDAR (menu-driven) DIALER modem controller 780 $ R AUTO DIAL:DIALER DTC Desk Top Calendar 780 $ DTC (menu-driven

  4. FIR Filter of DS-CDMA UWB Modem Transmitter

    NASA Astrophysics Data System (ADS)

    Kang, Kyu-Min; Cho, Sang-In; Won, Hui-Chul; Choi, Sang-Sung

    This letter presents low-complexity digital pulse shaping filter structures of a direct sequence code division multiple access (DS-CDMA) ultra wide-band (UWB) modem transmitter with a ternary spreading code. The proposed finite impulse response (FIR) filter structures using a look-up table (LUT) have the effect of saving the amount of memory by about 50% to 80% in comparison to the conventional FIR filter structures, and consequently are suitable for a high-speed parallel data process.

  5. Technical Issues in Evolving to Integrated Services Digital Network (ISDN)

    DTIC Science & Technology

    1991-06-01

    channel through some Page 13 Technical Issues in Evolving to ISDN Final Report separate interface (such as the AT command set of the Hayes modems or the...errors experienced over standard modem provided connectivity. But, in this project connectivity has been established only over a single CO. Those...examined to some extent and are discussed below. Existing equipment was of two types: that which treats ISDN as just another leased line providing 56k or

  6. Superficial view of fiber to the home (FTTH)

    NASA Astrophysics Data System (ADS)

    Li, Xiaolin

    2004-04-01

    For the past few years, telecom companies have been working diligently to provide us with pseudo-broadband Internet connections over copper (DSL) and cable (cable modem). I use the term "pseudo-broadband" because the existing telecom infrastructure can only provide speeds of up to 1.5 megabits per second. (In theory, cable modem can provide up to 2.5 megabits per second, but in reality nobody obtains these speeds because the shared aspects of cable modem results in lower speeds.) No doubt improvements will be made over the next few years to squeeze more out of copper and cable, but it doesn't matter, because fiber to the home is coming, and it will be here faster than most people predict. In case you're wondering, FTTH provides download speeds of up to 155 megabits per second -- that's 100 times faster than the pseudo-broadband DSL and cable modem connections. Can you say instantaneous data transfer? Can you say, video on demand? SBC and Bellsouth are two of the telecom giants pioneering FTTH. The initial markets are new residential construction, because you don't have to dig up streets in an existing neighborhood to lay the fiber optic cable. SBC plans to wire 6,000 homes in a community in San Francisco by late next year. Initial net connections will only be about 5 MB/second -- far from the theoretical maximum of 155 MB/second, but still blazingly fast compared to DSL and cable modem. BellSouth is also pioneering FTTH with a trial project involving more than 400 people in the Atlanta suburb of Dunwoody. These individuals have Internet connections of about 10 MB/second! No doubt there will be stumbles along the way to providing FTTH. No doubt there are challenges to making FTTH cost effective. No doubt it will take years before most residences in the world have true broadband Internet access.

  7. Thermospheric neutral wind profile in moonlit midnight by Lithium release experiments in Japan

    NASA Astrophysics Data System (ADS)

    Yamamoto, M. Y.; Watanabe, S.; Abe, T.; Kakinami, Y.; Habu, H.; Yamamoto, M.

    2015-12-01

    Neutral wind profiles were observed in lower thermosphere at about between 90 km and 130 km altitude by using resonance scattering light of moonlit Lithium (Li) vapor released from sounding rockets in midnight (with almost full-moon condition) in 2013 in Japan. As a target of the Daytime Dynamo campaign, Li release experiment was operated at Wallops Flight Facility (WFF) of NASA, U.S.A. in July, 2013 (Pfaff et al., 2015, this meeting), while the same kind of rocket-ground observation campaign in midnight was carried out by using S-520-27/S-310-42 sounding rockets in Uchinoura Space Center (USC) of JAXA, Kagoshima, Japan, also in July 2013.Since imaging signal-to-noise (S/N) condition of the experiment was so severe, we conducted to apply airborne observation for imaging the faint moonlit Li tracers so as to reduce the illuminating intensity of the background skies as an order of magnitude. Two independent methods for calculating the wind profile were applied to the Lithium emission image sequences successfully obtained by the airborne imaging by special Li imagers aboard the airplanes in order to derive precise information of Li tracers motion under the condition of single observation site on a moving aircraft along its flight path at about 12 km altitude in lower stratosphere. Slight attitude-feedback motion of the aircraft's 3-axes attitude changes (rolling, yawing and pitching) was considered for obtaining precise coordinates on each snapshot. Another approach is giving a simple mathematic function for wind profile to resolve the shape displacement of the imaged Li tracers. As a result, a wind profile in moonlit thermosphere was calculated in a range up to about 150 m/s with some fluctuated parts possibly disturbed by wind shears. In the same experiment, another sounding rocket S-310-42 with a TMA canister was also launched from USC/JAXA at about 1 hour before the rocket with carrying the Lithium canisters, thus, we can derive the other 2 profiles determined by the TMA chemical releases in up-leg and down-leg of the flight for the comparison. In this paper, we will report the obtained results of the moonlit Lithium emission intensities as well as method of wind profile calculations and final result of the comparison between the TMA and moonlit Lithium chemical releases in midnight lower thermosphere.

  8. Bi-directional communication interface for microprocessor-to-system/370

    NASA Technical Reports Server (NTRS)

    Fischer, J. P.

    1981-01-01

    The design and operation of a bi-directional communication interface between a microcomputer and the IBM System/370 is documented. The hardware unit interconnects a modem to interface to the S/370, the microcomputer with an EIA I/O port, and a terminal for sending and receiving data from either the microcomputer or the S/370. Also described is the software necessary for the two-way interface. This interface is designed so that no modifications need to be made to the terminal, modem, or microcomputer.

  9. An Automated Tool to Enable the Distributed Operations of Air Force Satellites

    DTIC Science & Technology

    2002-01-01

    workstations, home PCs, PDAs, pagers) over connections with various bandwidths (e.g., dial-up 56k , wireless 9.6k), SERS has different USis to support the...demonstration and evaluation activities, and (3) CERES employs more modem and open ground systems than are currently deployed in the space operations...COTS or custom tools. • Yes, we demonstrated that our software can interface with a modem Air Force ground system (CERES’ COBRA). • We identified new

  10. Study of Potential Standardization of Digital Freeze Frame Video Codecs.

    DTIC Science & Technology

    1984-01-01

    and MAR track an input clock over a very wide range. These are dependent on the modem used in any specific application. Interface connectors are those...terminals, 56K bit digital transmission sets). We have a limited custan capability and are not in the custom unit business. 1.,o .2e e.. , , 4g..2. . j...will) are designed for narrowband operation. We build our own modems which send .’e- pixels at a rate of 1969 pixels/second. Grey scale information is

  11. TWSTFT Network Status in the Pacific Rim Region and Development of a New Time Transfer Modem for TWSTFT

    DTIC Science & Technology

    2000-01-01

    32nd Annual Precise T ime and Time Interval ( P T T I ) Meeting TWSTFT NETWORK STATUS IN THE PACIFIC RIM REGION AND DEVELOPMENT OF A NEW TIME...TRANSFER MODEM FOR TWSTFT M. Imael, M. Hosokawal, Y . Hanadol, 2. Li2, P. Fisk3, Y . Nakadan4, and C. S. Liao5 ’Communications Research Laboratory...Metrology (NRLM), Japan 5Telecommunication Laboratories (TL) , Taipei, Taiwan Abstract Iko-Way Satellite Time and Frequency Transfer ( TWSTFT ) is one

  12. Results of an Internet survey determining the most frequently used ankle scores by AOFAS members.

    PubMed

    Lau, Johnny T C; Mahomed, Nizar M; Schon, Lew C

    2005-06-01

    With technological advances in ankle arthroplasty, there has been parallel development in the outcome instruments used to assess the results of surgery. The literature recommends the use of valid, reliable, and responsive ankle scores, but the ankle scores commonly used in clinical practice remain undefined. An internet survey of members of the American Orthopaedic Foot and Ankle Society (AOFAS) was conducted to determine which three ankle scores they perceived as most commonly used in the literature, which ones they believe are validated, which ones they prefer, and which they use in practice. According to respondents, the three most commonly used scores were the AOFAS Ankle score, the Foot Function Index (FFI), and the Musculoskeletal Outcomes Data Evaluation and Management System (MODEMS). The respondents believed that the AOFAS Ankle score, FFI, and MODEMS were validated. The FFI and MODEMS are validated, but the AOFAS ankle score is not validated. Most respondents preferred using the AOFAS Ankle score. The use of the empirical AOFAS Ankle score continues among AOFAS members.

  13. Development and characterisation of FPGA modems using forward error correction for FSOC

    NASA Astrophysics Data System (ADS)

    Mudge, Kerry A.; Grant, Kenneth J.; Clare, Bradley A.; Biggs, Colin L.; Cowley, William G.; Manning, Sean; Lechner, Gottfried

    2016-05-01

    In this paper we report on the performance of a free-space optical communications (FSOC) modem implemented in FPGA, with data rate variable up to 60 Mbps. To combat the effects of atmospheric scintillation, a 7/8 rate low density parity check (LDPC) forward error correction is implemented along with custom bit and frame synchronisation and a variable length interleaver. We report on the systematic performance evaluation of an optical communications link employing the FPGA modems using a laboratory test-bed to simulate the effects of atmospheric turbulence. Log-normal fading is imposed onto the transmitted free-space beam using a custom LabVIEW program and an acoustic-optic modulator. The scintillation index, transmitted optical power and the scintillation bandwidth can all be independently varied allowing testing over a wide range of optical channel conditions. In particular, bit-error-ratio (BER) performance for different interleaver lengths is investigated as a function of the scintillation bandwidth. The laboratory results are compared to field measurements over 1.5km.

  14. Timing and frequency considerations in the worldwide testing of a spread spectrum communication system

    NASA Technical Reports Server (NTRS)

    Woodring, D. G.; Nichols, S. A.; Swanson, R.

    1979-01-01

    During 1978 and 1979, an Air Force C-135 test aircraft was flown to various locations in the North and South Atlantic and Pacific Oceans for satellite communications experiments. A part of the equipment tested on the aircraft was the SEACOM spread spectrum modem. The SEACOM modem operated at X band frequency from the aircraft via the DSCS II satellite to a ground station. For data to be phased successfully, it was necessary to maintain independent time and frequency accuracy over relatively long periods of time (up to two weeks) on the aircraft and at the ground station. To achieve this goal, two Efratom atomic frequency standards were used. The performance of these frequency standards as used in the spread spectrum modem is discussed, including the effects of high relative velocity, synchronization and the effects of the frequency standards on data performance is discussed. The aircraft environment, which includes extremes of temperature, as well as long periods of shutdown followed by rapid warmup requirements, is also discussed.

  15. Molecular and isotopic composition of lipids in modern and fossil bivalve shells: Records of paleoenvironmental change?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    CoBabe, E.A.

    1995-12-31

    Suites of lipids residing in situ in modern and fossil bivalve shells offer new possibilities for the study of paleoecology and paleoclimatology. Distributions of carbon isotopic compositions of modem shell lipids suggests that many of these compounds, including alkanes, sterols, fatty acids, ketones and phytadienes, are derived from the bivalves and not directly from the surrounding environment. The occurrence of fatty acids in modem and fossil shell material opens up the possibility that saturation levels of these compounds may be used as paleothermometers. To date, the utility of fatty acids in paleoclimate studies has been limited because of the swiftmore » breakdown of these compounds in sediment. However, initial results indicate that fatty acids in bivalve shells retain their original structure for at least several million years. Comparison of modem bivalve shell fatty acids from tropical, temperate and polar nearshore marine systems will be presented, along with analogous fossil data.« less

  16. Soviet Navy Data Base: 1982-83,

    DTIC Science & Technology

    1983-04-01

    39) - Kilden DD w SSM 3 3 4 3 3 -Kashin w SSM 6 6 6 |19 6 - Kashin 13 13 13 13 - Kanin 8 8 8 8 8 - Kilden 1 1 - 1 1 - Kotlin 8 8 8 8 8 FFG (Krivak) 32...DD - (all) - - - 30-/ (27) - Kotlin 18 16 15 - 16 - Skory 7 13 12 - 11 FF/FFL - all - - - 140 (142) - Koni 1 1 1 - 1 - Riga 37 37 37 - 37 - Petya...CG/CL - Sverdlov - 1 3 - - DD - Skory 13 12 12 - 12/ - Kotlin - 2 - -G=1 FF - Riga 11 10 10 - 10 MSF - T-43 - 16 20 - 18 KGB Fcrces .- (114)iNi WFF

  17. Exacerbation of demyelinating syndrome after exposure to wireless modem with public hotspot.

    PubMed

    Johansson, Olle; Redmayne, Mary

    2016-01-01

    In August 2003, 48-year-old JS of Colorado, USA, a fitness therapist and sports nutritionist, contracted neuroinvasive West Nile virus which left her with disabilities due to spinal axonal damage.In August 2014, she suddenly developed symptoms very much like her acute West Nile infection 11 years ago, including focal seizures, ataxia, vertigo and headaches. Her blood count looked normal so there was no obvious infection. What struck her as odd was that when she left her apartment for any length of time, the symptoms stopped. She found out that a new type of wireless modem, enabled for both personal use and functioning as a public hotspot designed to reach up to 100 m, had been installed in the flat under hers.Her neighbor replaced the modem with a router without the hotspot feature. After that, the seizures stopped immediately, and the other symptoms faded gradually, after which she was fine and again could sleep well. Later, when another activated hotspot was installed in an adjacent flat, JS once again noticed symptoms.A possible association between electrohypersensitivity, myelin integrity and exposure to low-intensity radiofrequency electromagnetic fields (RF-EMF) typical in the modern world has recently been proposed. Since the West Nile virus attacks both the nerve cells and the glial ones, one explanation to the above observed case effects is that the initial virus attack and the wireless modem's RF-EMF affect the nervous system through the very same, or similar, avenues, and maybe both via the oligodendrocytes.

  18. MODEM: A comprehensive approach to modelling outcome and costs impacts of interventions for dementia. Protocol paper.

    PubMed

    Comas-Herrera, Adelina; Knapp, Martin; Wittenberg, Raphael; Banerjee, Sube; Bowling, Ann; Grundy, Emily; Jagger, Carol; Farina, Nicolas; Lombard, Daniel; Lorenz, Klara; McDaid, David

    2017-01-11

    The MODEM project (A comprehensive approach to MODelling outcome and costs impacts of interventions for DEMentia) explores how changes in arrangements for the future treatment and care of people living with dementia, and support for family and other unpaid carers, could result in better outcomes and more efficient use of resources. MODEM starts with a systematic mapping of the literature on effective and (potentially) cost-effective interventions in dementia care. Those findings, as well as data from a cohort, will then be used to model the quality of life and cost impacts of making these evidence-based interventions more widely available in England over the period from now to 2040. Modelling will use a suite of models, combining microsimulation and macrosimulation methods, modelling the costs and outcomes of care, both for an individual over the life-course from the point of dementia diagnosis, and for individuals and England as a whole in a particular year. Project outputs will include an online Dementia Evidence Toolkit, making evidence summaries and a literature database available free to anyone, papers in academic journals and other written outputs, and a MODEM Legacy Model, which will enable local commissioners of services to apply the model to their own populations. Modelling the effects of evidence-based cost-effective interventions and making this information widely available has the potential to improve the health and quality of life both of people with dementia and their carers, while ensuring that resources are used efficiently.

  19. Parachute Testing for the NASA X-38 Crew Return Vehicle

    NASA Technical Reports Server (NTRS)

    Stein, Jenny M.

    2005-01-01

    NASA's X-38 program was an in-house technology demonstration program to develop a Crew Return Vehicle (CRV) for the International Space Station capable of returning seven crewmembers to Earth when the Space Shuttle was not present at the station. The program, managed out of NASA's Johnson Space Center, was started in 1995 and was cancelled in 2003. Eight flights with a prototype atmospheric vehicle were successfully flown at Edwards Air Force Base, demonstrating the feasibility of a parachute landing system for spacecraft. The intensive testing conducted by the program included testing of large ram-air parafoils. The flight test techniques, instrumentation, and simulation models developed during the parachute test program culminated in the successful demonstration of a guided parafoil system to land a 25,000 Ib spacecraft. The test program utilized parafoils of sizes ranging from 750 to 7500 p. The guidance, navigation, and control system (GN&C) consisted of winches, laser or radar altimeter, global positioning system (GPS), magnetic compass, barometric altimeter, flight computer, and modems for uplink commands and downlink data. The winches were used to steer the parafoil and to perform the dynamic flare maneuver for a soft landing. The laser or radar altimeter was used to initiate the flare. In the event of a GPS failure, the software navigated by dead reckoning using the compass and barometric altimeter data. The GN&C test beds included platforms dropped from cargo aircraft, atmospheric vehicles released from a 8-52, and a Buckeye powered parachute. This paper will describe the test program and significant results.

  20. Real-time Kinematics Base Station and Survey Unit Setup Method for the Synchronous Impulse Reconstruction (SIRE) Radar

    DTIC Science & Technology

    2012-12-01

    GPS receiver, the Ashtech ProMark 500; a 3.4-GHz radio modem, the FreeWave 3400-SMR; a display unit, the Magellan MobileMapper CX; a 12-V battery pack...Figure 8. Bottom view of the ProMark 500. 3.1 Survey Unit RTK GPS Setup The following are the procedures for setting up...the RTK GPS Survey Unit: 1. Connect the radio modem to the ProMark 500 with serial cable #7 and #8. Display Screen Scroll Button Power LED Log

  1. The Operational Use of an Automated High Frequency Radio System Incorporating Automatic Link Establishment and Single-Tone Serial Modem Technology for U.S. Navy Ship-Shore Communications

    DTIC Science & Technology

    1993-10-01

    between the link chronologically in the following sections. quality analysis ( LQA ) score measured by ALE and single- tone serial modem performance. A...receiving ends in turn and (propagation permitting), pass traffic and terminate the are used to calculate a combined link quality analysis ( LQA ...score. The LQA score is displayed to the operator NCCOSC RDTE DIV installation team accomplished the as a number on an arbitrary scale of 0 to 120, with a

  2. Simulation study of communication link for Pioneer Saturn/Uranus atmospheric entry probe. [signal acquisition by candidate modem for radio link

    NASA Technical Reports Server (NTRS)

    Hinrichs, C. A.

    1974-01-01

    A digital simulation is presented for a candidate modem in a modeled atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the radio link conditions for an outer planets atmospheric entry probe. The results indicate that the signal acquisition characteristics and the channel error rate are acceptable for the system requirements of the radio link. The simulation also outputs data for calculating other error statistics and a quantized symbol stream from which error correction decoding can be analyzed.

  3. PILOT: A Precision Intercoastal Loran Translocator. Volume 3. Software.

    DTIC Science & Technology

    1982-03-01

    includes a second loran receiver (for cross chain operation), an interface or modem for remotely entering TD bias values, and a printer. b. The nucleus...developing an interface board to connect to the ship’s gyro, and a TD bias modem or box, replacing the large general purpose keyboard with a small predefined...The PILOT program has divided this memory into 8K of RAM and 56K of EPROM. Of the 56K bytes of EPROM, 40K are HP code and 16K are PILOT code (see Fig. 3

  4. National Program for Inspection of Non-Federal Dams. Prym Manufacturing Co. Dam (CT 00169), Thames River Basin, Killingly, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1979-06-01

    Service (DDS), which offers speeds of 19.2K bps and 56K bps. Instead of modems , DDS service requires a Channel Service Unit (CSU), to terminate each...Bell 103 modem that automatically calls for help if the DDS link goes down. DDS users can also use their own schemes to protect their transmissions...Switched 56 service provides 700 numbers for 56K transmission in some 60 odd cities, including areas such as Orlando, San Diego, and the Washington

  5. Real-Time Acquisition and Processing System (RTAPS) Version 1.1 Installation and User’s Manual.

    DTIC Science & Technology

    1986-08-01

    The language is incrementally compiled and procedure-oriented. It is run on an 8088 processor with 56K of available user RAM. The master board features...RTAPS/PC computers. The wiring configuration is shown in figure 10. Switch Modem Port MAC P5 or P6* 2, B4 3 B8 1%7 1 B10 *P6 recommended Figure 10. $MAC...activated switch. The AXAC output port is physically connected to the modem input on the switch. The subchannels are the labeled terminal connections

  6. Development of a Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    NASA Technical Reports Server (NTRS)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and. control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for inter-spacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of medium, moving platforms, and radiated power. The Path Emulator for RF Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  7. Characterization of a Prototype Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    NASA Technical Reports Server (NTRS)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for interspacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of the medium, moving platforms, and radiated power. The Path Emulator for Radio Frequency Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  8. A new modem for microwave time synchronisation via geosynchronous telecommunication satellites

    NASA Astrophysics Data System (ADS)

    Dienert, Michael

    1992-06-01

    A study illustrating the two way time transfer technique and describing the use of this technique with the MITREX (Microwave Time and Range Experiment) SATRE (Satellite Time and Range Experiment) modems is presented. The two way time transfer technique via geosynchronous telecom satellites is one of the most accurate methods for synchronization and comparison of remote clocks. Most of the unknown propagation delays can be eliminated by the two way principle. The use of a coherent spread spectrum technique with a truncated pseudonoise code offers a resolution better than 30 ps of the measured time interval. The receiver is built around a Delay Locked Loop (DLL), which correlates the received signal with the known PN sequence to derive the control signal of the loop. In the locked state both PN sequences are synchronous and tracking errors of less than 30 ps are possible. Results showing the accuracy of the modem depending on signal to noise ratio and variation of total input power levels are presented and show that the expected improvement of the jitter of the internal delay by an increase of the chip rate is possible.

  9. The Nano-Sat Exo-Brake Experiment: Status of the First Controlled De-Orbit (and Subsequent Experiments)

    NASA Technical Reports Server (NTRS)

    Murbach, M.; Guarneros Luna, A.; Alena, R.; Papadopoulos, P.; Stone, T.; Tanner, A.; Wheless, J.; Priscal, C.; Dono Perez, A.; Cianciolo, A; hide

    2017-01-01

    The design and operational experience with the first controlled Exo-Brake system flown during March, 2017, as conducted by the NASA Ames Research Center, is described. The Exo-Brake is an exo atmospheric braking and de-orbit device which had successfully flown twice before in a fixed-drag configuration on the nano-sat orbital platforms TechEdSat-3,4. The TechEdSat-5 flight, was the first to permit a commanded shape change which affected the drag (thus, ballistic coefficient), and thus allowed improved targeting. The use of the Iridium constellation and on-board Short Burst Data (SBD) modems, as well as Global Positioning Systems (GPS), permitted daily updates to be performed. This allowed compensation for the Thermosphere density variations captured in the F10.7 variable.Current and highly detailed analysis based on Monte-Carlo techniques suggest that approx. 7 modulations can achieve a relatively small <200km target ellipse at the Von Karman altitude. Drag data and over-all performance of the system is provided, as well as the description of the proposed subsequent experimental flights. There are noted advantaged for this type of de-orbit procedure as compared to a more traditional propulsion based de-orbit system.Also, the comparison with solar-sail type systems is shown to be favorable. The rapid flight series, of which this is a part, is conducted as a hands-on training environment for young professionals and university partners. In the future, such Exo-Brake systems may be used for more accurate nano-sat or small-sat disposal - or the development of technologies to permit on-demand sample return from Low Earth Orbit (LEO) scientific/manufacturing platforms.

  10. Colorectal Cancer Screening in the Elderly Population: Disparities by Dual Medicare–Medicaid Enrollment Status

    PubMed Central

    Koroukian, Siran M; Xu, Fang; Dor, Avi; Cooper, Gregory S

    2006-01-01

    Objectives To assess the disparities in colorectal cancer (CRC) screening between elderly dual Medicare–Medicaid enrollees (or duals), the most vulnerable subgroup of the Medicare population, and nonduals. Data Sources/Study Setting The 1999 Medicare Denominator File, the Medicare Outpatient Standard Analytic Files, and Physician Supplier Part B files. In addition, the 1998 Area Resource File was used as a source for county-level attributes. Data Collection/Extraction Methods CRC screening procedures for 1999—fecal occult blood test (FOBT), flexible sigmoidoscopy (FLEX), colonoscopy with FOBT and/or FLEX (COL-WFF), and colonoscopy only (COL-ONLY)—were extracted from claim records, using diagnostic and procedure codes. Duals (n =2.5 million) and nonduals (n =20.2 million) receiving their care through the fee-for-service system were identified from the Denominator file. Hierarchical logistic regression analysis was conducted to adjust for individual- and county-level characteristics. Principal Findings Compared with nonduals, duals were disproportionately represented by female, older-old, and minority individuals (respectively 74.4 versus 58.5 percent; 19.3 versus 10.8 percent; 35.7 versus 8.0 percent), and CRC screening was significantly lower in duals than in nonduals (5.1 versus 12.2 percent for FOBT adjusted odds ratio [AOR]: 0.48, 95 percent confidence interval [CI]: 0.45–0.51); 0.7 versus 1.9 percent for FLEX, (AOR: 0.55, 95 percent CI: 0.49–0.61); 0.4 versus 0.8 percent for COL-WFF (AOR: 0.60, 95 percent CI: 0.54–0.67); and 1.8 versus 2.5 percent for COL-ONLY (AOR: 0.85, 95 percent CI: 0.80–0.89); p<.001 for all comparisons. Conclusions Duals are significantly less likely than nonduals to undergo CRC screening, even after adjusting for individual- and county-level covariates. Future studies should evaluate the contribution of comorbidity and low socioeconomic status to these disparities. PMID:17116113

  11. High-sensitivity DPSK receiver for high-bandwidth free-space optical communication links.

    PubMed

    Juarez, Juan C; Young, David W; Sluz, Joseph E; Stotts, Larry B

    2011-05-23

    A high-sensitivity modem and high-dynamic range optical automatic gain controller (OAGC) have been developed to provide maximum link margin and to overcome the dynamic nature of free-space optical links. A sensitivity of -48.9 dBm (10 photons per bit) at 10 Gbps was achieved employing a return-to-zero differential phase shift keying based modem and a commercial Reed-Solomon forward error correction system. Low-noise optical gain was provided by an OAGC with a noise figure of 4.1 dB (including system required input loses) and a dynamic range of greater than 60 dB.

  12. Estimation of frequency offset in mobile satellite modems

    NASA Technical Reports Server (NTRS)

    Cowley, W. G.; Rice, M.; Mclean, A. N.

    1993-01-01

    In mobilesat applications, frequency offset on the received signal must be estimated and removed prior to further modem processing. A straightforward method of estimating the carrier frequency offset is to raise the received MPSK signal to the M-th power, and then estimate the location of the peak spectral component. An analysis of the lower signal to noise threshold of this method is carried out for BPSK signals. Predicted thresholds are compared to simulation results. It is shown how the method can be extended to pi/M MPSK signals. A real-time implementation of frequency offset estimation for the Australian mobile satellite system is described.

  13. A novel scheme to aid coherent detection of GMSK signals in fast Rayleigh fading channels

    NASA Technical Reports Server (NTRS)

    Leung, Patrick S. K.; Feher, Kamilo

    1990-01-01

    A novel scheme to insert carrier pilot to Gaussian Minimum Shift Keying (GMSK) signal using Binary Block Code (BBC) and a highpass filter in baseband is proposed. This allows the signal to be coherently demodulated even in a fast Rayleigh fading environment. As an illustrative example, the scheme is applied to a 16 kb/s GMSK signal, and its performance over a fast Rayleigh fading channel is investigated using computer simulation. This modem's 'irreducible error rate' is found to be Pe = 5.5 x 10(exp -5) which is more than that of differential detection. The modem's performance in Rician fading channel is currently under investigation.

  14. A wideband software reconfigurable modem

    NASA Astrophysics Data System (ADS)

    Turner, J. H., Jr.; Vickers, H.

    A wideband modem is described which provides signal processing capability for four Lx-band signals employing QPSK, MSK and PPM waveforms and employs a software reconfigurable architecture for maximum system flexibility and graceful degradation. The current processor uses a 2901 and two 8086 microprocessors per channel and performs acquisition, tracking, and data demodulation for JITDS, GPS, IFF and TACAN systems. The next generation processor will be implemented using a VHSIC chip set employing a programmable complex array vector processor module, a GP computer module, customized gate array modules, and a digital array correlator. This integrated processor has application to a wide number of diverse system waveforms, and will bring the benefits of VHSIC technology insertion into avionic antijam communications systems.

  15. Design Memorandum with Environmental Assessment for Raccoon River and Walnut Creek, West Des Moines and Des Moines, Iowa Local Flood Protection Project. Revision

    DTIC Science & Technology

    1991-06-01

    pervious 15’ Levee - Walnut Creek (f) substratum (sand) 4A 197 thru fill, 5’ into 15’ Levee - Walnut Creek ( 56k ) sand 4B 195 thru fill, 5’ into 15...expand ram memory to 2 megabyte plus nemory chips. 4.5.2.4 Two (2) external 2400 bps phone modems (Hayes). 4.5.2.5 Four port serial multiplexer. 4.5.2.6...Two (2) external 2400 bps phone modems (Hayes). 5.1.1.2.5 Four port serial multiplexer. 5.1.1.2.6 One (1) Okidata 393C 120/450 printer and 2 color

  16. Modem transmission of data for 3D fracture modeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chaudhary, S.A.; Rodgerson, J.L.; Martinez, A.D.

    1996-06-01

    Hydraulic fracturing treatments require measurement of numerous parameters, including surface rates and pressures, to quantify fluids, proppant, and additives. Computers are used to acquire data for the purpose of calculating bottomhole pressure (BHP), compiling quality-control data, generating diagnostic plots, and, often, for modeling fracture geometry in real time. In the recent past, modems have been routinely used in conjunction with cellular phone systems to transmit field-monitored data to a remote office. More recently, these data have been used at the remote site to perform 3D fracture modeling for design verification and adjustment. This paper describes data-transmission technology and discusses themore » related cost and reliability.« less

  17. BaR-SPOrt: the instrument to be accommodated at Dome C

    NASA Astrophysics Data System (ADS)

    Zannoni, M.; Carretti, E.; Cortiglioni, S.; Macculi, C.; Ramponi, M.; Sbarra, C.; Ventura, G.; Monari, J.; Poloni, M.; Poppi, S.; Natale, V.; Nesti, R.; Baralis, M.; Peverini, O.; Tascone, R.; Virone, G.; Boscaleri, A.; Boella, G.; Sironi, G.; Gervasi, M.; de Bernardis, P.; Masi, S.; de Petris, M.

    The BaR-SPOrt (Balloon-Borne Radiometers for Sky Polarization Observations) experiment, a program of the Agenzia Spaziale Italiana (ASI) co-funded by PNRA (Progetto Nazionale di Ricerca in Antartide) was originally designed as a payload for long duration balloons flights. The changing scenario, both scientific and strategic, has led us to propose it for the starting winter campaign of at the Concordia Base. Here the instrument and the features making it suitable to operate at Dome-C are described. After the initial setup, BaR-SPOrt should not require any kind of routine intervention by a dedicated base staff. The experiment will just need electrical power (less than 2 kW) and a suitable accommodation on the field. It can be fully monitored and controlled, including the data acquisition, through its own telemetry/telecommand link using IRIDIUM modems. Both the receiver and the critical electronics are housed inside a temperature-controlled vacuum chamber, providing the properly stabilized environment. The cold part of the radiometer employs a closed loop mechanical cryo-cooler that provides temperatures <70 ±0.1 K with low power consumption (<200 W).

  18. The Advanced Communication Technology Satellite and ISDN

    NASA Technical Reports Server (NTRS)

    Lowry, Peter A.

    1996-01-01

    This paper depicts the Advanced Communication Technology Satellite (ACTS) system as a global central office switch. The ground portion of the system is the collection of earth stations or T1-VSAT's (T1 very small aperture terminals). The control software for the T1-VSAT's resides in a single CPU. The software consists of two modules, the modem manager and the call manager. The modem manager (MM) controls the RF modem portion of the T1-VSAT. It processes the orderwires from the satellite or from signaling generated by the call manager (CM). The CM controls the Recom Laboratories MSPs by receiving signaling messages from the stacked MSP shelves ro units and sending appropriate setup commands to them. There are two methods used to setup and process calls in the CM; first by dialing up a circuit using a standard telephone handset or, secondly by using an external processor connected to the CPU's second COM port, by sending and receiving signaling orderwires. It is the use of the external processor which permits the ISDN (Integrated Services Digital Network) Signaling Processor to implement ISDN calls. In August 1993, the initial testing of the ISDN Signaling Processor was carried out at ACTS System Test at Lockheed Marietta, Princeton, NJ using the spacecraft in its test configuration on the ground.

  19. Effects of ocean thermocline variability on noncoherent underwater acoustic communications.

    PubMed

    Siderius, Martin; Porter, Michael B; Hursky, Paul; McDonald, Vincent

    2007-04-01

    The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been conducting experiments to study these environmental effects on various modulation schemes. Here the focus is on the role of the thermocline on a widely used modulation scheme (frequency-shift keying). Using data from a recent experiment conducted in 100-m-deep water off the coast of Kauai, HI, frequency-shift-key modulation performance is shown to be strongly affected by diurnal cycles in the thermocline. There is dramatic variation in performance (measured by bit error rates) between receivers in the surface duct and receivers in the thermocline. To interpret the performance variations in a quantitative way, a precise metric is introduced based on a signal-to-interference-noise ratio that encompasses both the ambient noise and intersymbol interference. Further, it will be shown that differences in the fading statistics for receivers in and out of the thermocline explain the differences in modem performance.

  20. A measurement-driven approach to assess power line telecommunication (PLT) network quality of service (QoS) performance parameters

    NASA Astrophysics Data System (ADS)

    Betta, G.; Capriglione, D.; Ferrigno, L.; Laracca, M.

    2009-10-01

    Power line telecommunication (PLT) technology offers cheap and fast ways for providing in-home broadband services and local area networking. Its main advantage is due to the possibility of using the pre-existing electrical grid as a communication channel. Nevertheless, technical challenges arise from the difficulty of operating on a hostile medium, not designed for communication purposes, characterized by complex channel modeling and by varying time response. These aspects put practical problems for designers and testers in the assessment of network quality of service performance parameters such as the throughput, the latency, the jitter, and the reliability. The measurement of these parameters has not yet been standardized so that there do not exist reference test set-ups and measurement methodologies (i.e. the type of isolation from the ac main, the observation time and the number of experiments, the measurement uncertainty and so on). Consequently, experiments executed by adopting different methods may lead to incompatible measurement results, thus making it also impossible to have reliable comparisons of different PLT modems. Really, the development of standard procedures is a very difficult task because the scenarios in which the PLT modems can work are very wide and then the application of an exhaustive approach (in which all the parameters influencing the PLT performance should be considered) would be very complex and time consuming, thus making the modem characterization very expensive. In this paper, the authors propose a methodological approach to develop an efficient measurement procedure able to reliably assess the performance of PLT modems (in terms of network quality of service parameters) with a minimum number of experiments. It is based on both creating a reconfigurable grid to which real disturbing loads are connected and implementing an original design of the experiment technique based on the effects of the uncertainty of the measurement results. Methods are also provided to analyze measurement results and to estimate the measurement uncertainty.

  1. Gondola development for CNES stratospheric balloons

    NASA Astrophysics Data System (ADS)

    Vargas, A.; Audoubert, J.; Cau, M.; Evrard, J.; Verdier, N.

    The CNES has been supporting scientific ballooning since its establishment in 1962. The two main parts of the balloon system or aerostat are the balloon itself and the flight train, comprising the house-keeping gondola, for the control of balloon flight (localization and operational telemetry & telecommand - TM/TC), and the scientific gondola with its dedicated telecommunication system. For zero pressure balloon, the development of new TM/TC system for the housekeeping and science data transmission are going on from 1999. The main concepts are : - for balloon house-keeping and low rate scientific telemetry, the ELITE system, which is based on single I2C bus standardizing communication between the different components of the system : trajectography, balloon control, power supply, scientific TM/TC, .... In this concept, Radio Frequency links are developed between the house keeping gondola and the components of the aerostat (balloon valve, ballast machine, balloon gas temperature measurements, ...). The main objectives are to simplify the flight train preparation in term of gondola testing before flight, and also by reducing the number of long electrical cables integrated in the balloon and the flight train; - for high rate scientific telemetry, the use of functional interconnection Internet Protocol (IP) in interface with the Radio Frequency link. The main idea is to use off-the-shelf IP hardware products (routers, industrial PC, ...) and IP software (Telnet, FTP, Web-HTTP, ...) to reduce the development costs; - for safety increase, the adding, in the flight train, of a totally independent house keeping gondola based on the satellite Inmarsat M and Iridium telecommunication systems, which permits to get real time communications between the on-board data mobile and the ground station, reduced to a PC computer with modem connected to the phone network. These GEO and LEO telecommunication systems give also the capability to operate balloon flights over longer distance (over the line of sight) than with dedicated RF system, which requires balloon visibility from the ground station. For long duration flights (3 months) of Infra Red Montgolfieres, a house keeping gondola has been developed, using the Inmarsat C standard to have communication all around the world (up to N or S 80 ° latitude) with an automatic switching between the 4 geostationnary Inmarsat satellites. After validation flights performed from Bauru / Brazil. (2000 & 2001) and Kiruna/Sweden (2002), the first operational flights took place from Bauru in February 2003 during ENVISAT validation campaign. The next flights will be realized in the framework of the Hibiscus campaign planned in February 2004 in Bauru.. The Balloon Division was involved in the Franco / Japanese HSFD II project which consists to drop a mock-up of the Japanese HOPE-X space shuttle from a stratospheric balloon to validate its flight from the altitude of 30 km. We developed a specific gondola as a service module for the HOPE-X shuttle, providing power and GPS radio-frequency signal during the balloon flight phase, telemetry end remote control radio frequency links and separation system with pyrotechnic cutters for the drop of the shuttle. A successful flight was performed at Kiruna in July 2003. Concerning gondola with pointing system, the study of a big g-ray telescope (8 m of focal length), started by the end of 2002. For this 1 ton gondola, the telescope stabilization system will be based on control moment gyro (CMG). The CMG system has been designed and will be manufactured and validated during 2004. The first flight of this g-ray gondola is planned for 2006. The progress, status and future plans concerning these gondola developments will be presented.

  2. Icecube: Spaceflight Validation of an 874-GHz Submillimeter Wave Radiometer for Ice Cloud Remote Sensing

    NASA Astrophysics Data System (ADS)

    Wu, D. L.; Esper, J.; Ehsan, N.; Piepmeier, J. R.; Racette, P.

    2014-12-01

    Ice clouds play a key role in the Earth's radiation budget, mostly through their strong regulation of infrared radiation exchange. Submillimeter wave remote sensing offers a unique capability to improve cloud ice measurements from space. At 874 GHz cloud scattering produces a larger brightness temperature depression from cirrus than lower frequencies, which can be used to retrieve vertically-integrated cloud ice water path (IWP) and ice particle size. The objective of the IceCube project is to retire risks of 874-GHz receiver technology by raising its TRL from 5 to 7. The project will demonstrate, on a 3-U CubeSat in a low Earth orbit (LEO) environment, the 874-GHz receiver system with noise equivalent differential temperature (NEDT) of ~0.2 K for 1-second integration and calibration error of 2.0 K or less as measured from deep-space observations. The Goddard Space Flight Center (GSFC) is partnering with Virginia Diodes, Inc (VDI) to qualify commercially available 874-GHz receiver technology for spaceflight, and demonstrate the radiometer performance. The instrument (submm-wave cloud radiometer, or SCR), along with the CubeSat system developed and integrated by GSFC, will be ready for launch in two years. The instrument subsystem includes a reflector antenna, sub-millimeter wave mixer, frequency multipliers and stable local oscillator, an intermediate frequency (IF) circuit with noise injection, and data-power boards. The mixer and frequency multipliers are procured from VDI with GSFC insight into fabrication and testing processes to ensure scalability to spaceflight beyond TRL 7. The remaining components are a combination of GSFC-designed and commercial off-the-shelf (COTS) at TRLs of 5 or higher. The spacecraft system is specified by GSFC and comprises COTS components including three-axis stabilizer and sun sensor, GPS receiver, deployable solar arrays, UHF radio, and 2 GB of on-board storage. The spacecraft and instrument are integrated and flight qualified through environmental testing at GSFC. The concept of operations is to fly the GSFC designed instrument/spacecraft in a LEO orbit and collect the 874-GHz radiance data for a period of at least 28+ days. Communication will be through the WFF's UHF ground station. Mission Operations and data processing and validation will be conducted at GSFC.

  3. Microfossils of Cyanobacteria in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    2007-01-01

    During the past decade, Environmental and Field Emission Scanning Electron Microscopes have been used at the NASA/Marshall Space Flight Center to investigate freshly fractured interior surfaces of a large number of different types of meteorites. Large, complex, microfossils with clearly recognizable biological affinities have been found embedded in several carbonaceous meteorites. Similar forms were notably absent in all stony and nickel-iron meteorites investigated. The forms encountered are consistent in size and morphology with morphotypes of known genera of Cyanobacteria and microorganisms that are typically encountered in associated benthic prokaryotic mats. Even though many coccoidal and isodiametric filamentous cyanobacteria have a strong morphological convergence with some other spherical and filamentous bacteria and algae, many genera of heteropolar cyanobacteria have distinctive apical and basal regions and cellular differentiation that makes it possible to unambiguously recognize the forms based entirely upon cellular dimensions, filament size and distinctive morphological characteristics. For almost two centuries, these morphological characteristics have historically provided the basis for the systematics and taxonomy of cyanobacteria. This paper presents ESEM and FESEM images of embedded filaments and thick mats found in-situ in the Murchison CM2 and Orgueil cn carbonaceous meteorites. Comparative images are also provided for known genera and species of cyanobacteria and other microbial extremophiles. Energy Dispersive X-ray Spectroscopy (EDS) studies indicate that the meteorite filaments typically exhibit dramatic chemical differentiation with distinctive difference between the possible microfossil and the meteorite matrix in the immediate proximity. Chemical differentiation is also observed within these microstructures with many of the permineralized filaments enveloped within electron transparent carbonaceous sheaths. Elemental distributions of these embedded filaments are not consistent with recent cyanobacteria or other living or preserved microbial extremophiles that have been investigated during this research. The meteorite filaments often have nitrogen content below the sensitivity level of the EDS detector. Carbon, Sulphur, Iron or Silicon are often highly enriched and hence anomalous C/N and CIS ratios when compared with modem cyanobacteria. The meteorite forms that are unambiguously recognizable as biological filaments are interpreted as indigenous microfossils analogous to several known genera of modem cyanobacteria and associated trichomic filamentous prokaryotes.

  4. Infrared transmission of electronic information via LAN in the operating room.

    PubMed

    Hagihira, S; Takashina, M; Mori, T; Taenaka, N; Mashimo, T; Yoshiya, I

    2000-01-01

    Recent advances in technology have brought many kinds of monitoring devices into the operating room (OR). The information gathered by monitors can be channeled to the operating ward information system via a local area network (LAN). Connecting patients to monitors and monitors to the LAN, however, requires a large number of cables. This wiring is generally inconvenient and particularly troublesome if the layout of the OR is rearranged. From this point of view, wireless transmission seems ideally suited to clinical settings. Currently, two modes of wireless connectivity are available: radio-frequency (RF) waves or infrared (IR) waves. Some reports suggest that RF transmission is likely to cause electromagnetic interference (EMI) in medical devices such as cardiac pacemakers or infusion pumps. The risk of malfunctioning life-sustaining devices and the catastrophic consequences this would have on seriously ill patients rules out the use of RF. Here, we report an IR system using IR modems for LAN connectivity in the OR. In this study, we focused on the possible detrimental effects of EMI during wireless connectivity. In our trial, we found no evidence of EMI of IR modems with any of the medical devices we tested. Furthermore, IR modems showed similar performance to a wired system even in an electrically noisy environment. We conclude that IR wireless connectivity can be safely and effectively used in ORs.

  5. En route Spacing Tool: Efficient Conflict-free Spacing to Flow-Restricted Airspace

    NASA Technical Reports Server (NTRS)

    Green, S.

    1999-01-01

    This paper describes the Air Traffic Management (ATM) problem within the U.S. of flow-restricted en route airspace, an assessment of its impact on airspace users, and a set of near-term tools and procedures to resolve the problem. The FAA is committed, over the next few years, to deploy the first generation of modem ATM decision support tool (DST) technology under the Free-Flight Phase-1 (FFp1) program. The associated en route tools include the User Request Evaluation Tool (URET) and the Traffic Management Advisor (TMA). URET is an initial conflict probe (ICP) capability that assists controllers with the detection and resolution of conflicts in en route airspace. TMA orchestrates arrivals transitioning into high-density terminal airspace by providing controllers with scheduled times of arrival (STA) and delay feedback advisories to assist with STA conformance. However, these FFPl capabilities do not mitigate the en route Miles-In-Trail (MIT) restrictions that are dynamically applied to mitigate airspace congestion. National statistics indicate that en route facilities (Centers) apply Miles-In-Trail (MIT) restrictions for approximately 5000 hours per month. Based on results from this study, an estimated 45,000 flights are impacted by these restrictions each month. Current-day practices for implementing these restrictions result in additional controller workload and an economic impact of which the fuel penalty alone may approach several hundred dollars per flight. To mitigate much of the impact of these restrictions on users and controller workload, a DST and procedures are presented. The DST is based on a simple derivative of FFP1 technology that is designed to introduce a set of simple tools for flow-rate (spacing) conformance and integrate them with conflict-probe capabilities. The tool and associated algorithms are described based on a concept prototype implemented within the CTAS baseline in 1995. A traffic scenario is used to illustrate the controller's use of the tool, and potential display options are presented for future controller evaluation.

  6. The Use of a Satellite Communications System for Command and Control of the National Aeronautics and Space Administration Surrogate Unmanned Aerial System Research Aircraft

    NASA Technical Reports Server (NTRS)

    Howell, Charles T.; Jones, Frank; Hutchinson, Brian; Joyce, Claude; Nelson, Skip; Melum, Mike

    2017-01-01

    The NASA Langley Research Center has transformed a Cirrus Design SR22 general aviation (GA) aircraft into an Unmanned Aerial Systems (UAS) Surrogate research aircraft which has served for several years as a platform for unmanned systems research and development. The aircraft is manned with a Safety Pilot and a Research Systems Operator (RSO) that allows for flight operations almost any-where in the national airspace system (NAS) without the need for a Federal Aviation Administration (FAA) Certificate of Authorization (COA). The UAS Surrogate can be remotely controlled from a modular, transportable ground control station (GCS) like a true UAS. Ground control of the aircraft is accomplished by the use of data links that allow the two-way passage of the required data to control the aircraft and provide the GCS with situational awareness. The original UAS Surrogate data-link system was composed of redundant very high frequency (VHF) data radio modems with a maximum range of approximately 40 nautical miles. A new requirement was developed to extend this range beyond visual range (BVR). This new requirement led to the development of a satellite communications system that provided the means to command and control the UAS Surrogate at ranges beyond the limits of the VHF data links. The system makes use of the Globalstar low earth orbit (LEO) satellite communications system. This paper will provide details of the development, implementation, and flight testing of the satellite data communications system on the UAS Surrogate research aircraft.

  7. Design of anti-theft/cable cut real time alert system for copper cable using microcontroller and GSM technology

    NASA Astrophysics Data System (ADS)

    Lim, E. K.; Norizan, M. N.; Mohamad, I. S.; Yasin, M. N. M.; Murad, S. A. Z.; Baharum, N. A.; Jamalullail, N.

    2017-09-01

    This paper presents the design of anti-theft/cable cut real time alert system using microcontroller and GSM technology. The detection part is using the electrical circuit wire connection in detecting the voltage drop of the cable inside the microcontroller digital input port. The GSM wireless modem is used to send the location of cable cut directly to the authority mobile phone. Microcontroller SK40C with Microchip PIC16F887 is used as a controller to control the wireless modem and also the detection device. The device is able to detect and display the location of the cable cut on the LCD display besides of and sending out the location of the cable break to the authority mobile phone wirelessly via SMS.

  8. Development of a PLC modem for data transmission over a PWM power supply

    NASA Astrophysics Data System (ADS)

    Batard, Christophe; Ginot, Nicolas; Mannah, Marc Anthony; Millet, Christophe; Poitiers, Frédéric

    2014-04-01

    In variable-speed electrical drive and online conditioning monitoring, a feedback loop is required in order to transmit the sensor information from the motor to the controller close to the inverter. Additional cabling is used for signalling. This extra cabling has a significant cost and data transmission may not be reliable. Thus, the use of power line communication (PLC) technology to transmit data in motor drive application is quite interesting. The use of a PLC modem dedicated to the home network in a three-phase inverter-fed motor power cable does not work. Therefore, specific coupling interfaces are developed to transmit data through a pulse-width modulated power supply. Laboratory tests have shown that the couplers are operating properly. They ensure reliable data transmission in a motor drive application.

  9. Visiting Old Libraries: Scientific Books in the Religious Institutions of Early Modem Portugal.

    PubMed

    Giurgevich, Luana

    2016-08-01

    Knowledge of libraries and book collecting is a preliminary task for the characterisation of scientific culture and practice. In the case of Iberia, and especially Portugal, this is still a desideratum. This paper provides a first global look at this issue. In early modem Portugal religious institutions organised impressive collections of books, by far the largest in the country These libraries not only served the religious institutions themselves, but also supplied books to lesser libraries, such as the University Library of Coimbra and the Royal Library. The Portuguese book market mirrored the purchase and selection of books made by religious congregations. This was also true for the circulation of scientific books, which depended above all on the interests, choices and cultural relations of these most peculiar book collectors.

  10. Autonomous Mobile Platform for Research in Cooperative Robotics

    NASA Technical Reports Server (NTRS)

    Daemi, Ali; Pena, Edward; Ferguson, Paul

    1998-01-01

    This paper describes the design and development of a platform for research in cooperative mobile robotics. The structure and mechanics of the vehicles are based on R/C cars. The vehicle is rendered mobile by a DC motor and servo motor. The perception of the robot's environment is achieved using IR sensors and a central vision system. A laptop computer processes images from a CCD camera located above the testing area to determine the position of objects in sight. This information is sent to each robot via RF modem. Each robot is operated by a Motorola 68HC11E micro-controller, and all actions of the robots are realized through the connections of IR sensors, modem, and motors. The intelligent behavior of each robot is based on a hierarchical fuzzy-rule based approach.

  11. A novel high-speed PLC communication modem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abraham, K.C.; Roy, S.

    1992-10-01

    In this paper an innovative design for power line carrier (PLC) communication using digitally modulated signals is presented. The major contribution consists of a new signal coupler to the power line that achieves a stable transmission bandwidth of 4 KHz on distribution lines over long distances. Preliminary field tests achieved half-duplex operation at 1.2 Kbaud over a distribution power line to the 120V network and back with a symbol error rate of about 2% using less than about 10 W of average transmitted power, which is considerably superior to the present state-of-the-art PLC modems. Full-duplex operation over 120/240V intra-building wiringmore » has also been field tested at 9.6 Kbaud over distances of 3000 ft. using 1W of average transmitted power.« less

  12. Performance of convolutionally encoded noncoherent MFSK modem in fading channels

    NASA Technical Reports Server (NTRS)

    Modestino, J. W.; Mui, S. Y.

    1976-01-01

    The performance of a convolutionally encoded noncoherent multiple-frequency shift-keyed (MFSK) modem utilizing Viterbi maximum-likelihood decoding and operating on a fading channel is described. Both the lognormal and classical Rician fading channels are considered for both slow and time-varying channel conditions. Primary interest is in the resulting bit error rate as a function of the ratio between the energy per transmitted information bit and noise spectral density, parameterized by both the fading channel and code parameters. Fairly general upper bounds on bit error probability are provided and compared with simulation results in the two extremes of zero and infinite channel memory. The efficacy of simple block interleaving in combatting channel memory effects are thoroughly explored. Both quantized and unquantized receiver outputs are considered.

  13. Wind-Driven Montgolfiere Balloons for Mars

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Fairbrother, Debora; Lemieux, Aimee; Lachenmeier, Tim; Zubrin, Robert

    2005-01-01

    Solar Montgolfiere balloons, or solar-heated hot air balloons have been evaluated by use on Mars for about 5 years. In the past, JPL has developed thermal models that have been confirmed, as well as developed altitude control systems to allow the balloons to float over the landscape or carry ground sampling instrumentation. Pioneer Astronautics has developed and tested a landing system for Montgolfieres. JPL, together with GSSL. have successfully deployed small Montgolfieres (<15-m diameter) in the earth's stratosphere, where conditions are similar to a Mars deployment. Two larger Montgolfieres failed, however, and a series of larger scale Montgolfieres is now planned using stronger, more uniform polyethylene bilaminate, combined with stress-reducing ripstitch and reduced parachute deceleration velocities. This program, which is presently under way, is a joint effort between JPL, WFF, and GSSL, and is planned for completion in three years.

  14. Code Optimization Techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    MAGEE,GLEN I.

    Computers transfer data in a number of different ways. Whether through a serial port, a parallel port, over a modem, over an ethernet cable, or internally from a hard disk to memory, some data will be lost. To compensate for that loss, numerous error detection and correction algorithms have been developed. One of the most common error correction codes is the Reed-Solomon code, which is a special subset of BCH (Bose-Chaudhuri-Hocquenghem) linear cyclic block codes. In the AURA project, an unmanned aircraft sends the data it collects back to earth so it can be analyzed during flight and possible flightmore » modifications made. To counter possible data corruption during transmission, the data is encoded using a multi-block Reed-Solomon implementation with a possibly shortened final block. In order to maximize the amount of data transmitted, it was necessary to reduce the computation time of a Reed-Solomon encoding to three percent of the processor's time. To achieve such a reduction, many code optimization techniques were employed. This paper outlines the steps taken to reduce the processing time of a Reed-Solomon encoding and the insight into modern optimization techniques gained from the experience.« less

  15. The Road to the Global Village.

    ERIC Educational Resources Information Center

    Wright, Karen

    1990-01-01

    Discussed is the growth and development of electronic communications and computer technology. Modems, the "Whole Person Paradigm," artificial intelligence, multimedia, virtual reality, and communications technologies are described. Implications for world economies are suggested. (CW)

  16. 36Cl: A tracer in groundwater in the aquia formation of Southern Maryland

    USGS Publications Warehouse

    Purdy, C.B.; Mignerey, A.C.; Helz, G.R.; Drummond, D.D.; Kubik, P.W.; Elmore, D.; Hemmick, T.

    1987-01-01

    The Aquia Formation (Paleocene) of Southern Maryland, a marine unit consisting predominantly of quartz sands, but containing 20-40% glauconite, represents one of the many productive, heavily pumped aquifers of the Southeastern Coastal Plain. An unusually high 36Cl activity ( ~ 15 ?? modem water) measured in an outcrop sample is interpreted as a result of the bomb pulse input. About 25 km downdip from the recharge area, a minimum in total chloride concentration occurs. This minimum is thought to correlate with the latest low-stand of sea-level, and thus to provide time information which is in general agreement with ages calculated from hydrodynamic data. However, significant increases in the 36Cl concentrations are observed along the flow path which may be due to ion filtration or to leakage of modem, bomb-contaminated water into the Aquia aquifer. ?? 1987.

  17. Comparison of Model Prediction with Measurements of Galactic Background Noise at L-Band

    NASA Technical Reports Server (NTRS)

    LeVine, David M.; Abraham, Saji; Kerr, Yann H.; Wilson, Willam J.; Skou, Niels; Sobjaerg, S.

    2004-01-01

    The spectral window at L-band (1.413 GHz) is important for passive remote sensing of surface parameters such as soil moisture and sea surface salinity that are needed to understand the hydrological cycle and ocean circulation. Radiation from celestial (mostly galactic) sources is strong in this window and an accurate accounting for this background radiation is often needed for calibration. Modem radio astronomy measurements in this spectral window have been converted into a brightness temperature map of the celestial sky at L-band suitable for use in correcting passive measurements. This paper presents a comparison of the background radiation predicted by this map with measurements made with several modem L-band remote sensing radiometers. The agreement validates the map and the procedure for locating the source of down-welling radiation.

  18. Pilot symbol-assisted beamforming algorithms in the WCDMA reverse link

    NASA Astrophysics Data System (ADS)

    Kong, Dongkeon; Lee, Jong H.; Chun, Joohwan; Woo, Yeon Sik; Soh, Ju Won

    2001-08-01

    We present a pilot symbol-assisted beamforming algorithm and a simulation tool of smart antennas for Wideband Code Division Multiple Access (WCDMA) in reverse link. In the 3GPP WCDMA system smart antenna technology has more room to play with than in the second generation wireless mobile systems such as IS-95 because the pilot symbol in Dedicated Physical Control Channel (DPCCH) can be utilized. First we show a smart antenna structure and adaptation algorithms, and then we explain a low-level smart antenna implementation using Simulink and MATLAB. In the design of our smart antenna system we pay special attention for the easiness of the interface to the baseband modem; Our ultimate goal is to implement a baseband smart antenna chip sets that can easily be added to to-be-existed baseband WCDMA modem units.

  19. Component Technology for High-Performance Scientific Simulation Software

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Epperly, T; Kohn, S; Kumfert, G

    2000-11-09

    We are developing scientific software component technology to manage the complexity of modem, parallel simulation software and increase the interoperability and re-use of scientific software packages. In this paper, we describe a language interoperability tool named Babel that enables the creation and distribution of language-independent software libraries using interface definition language (IDL) techniques. We have created a scientific IDL that focuses on the unique interface description needs of scientific codes, such as complex numbers, dense multidimensional arrays, complicated data types, and parallelism. Preliminary results indicate that in addition to language interoperability, this approach provides useful tools for thinking about themore » design of modem object-oriented scientific software libraries. Finally, we also describe a web-based component repository called Alexandria that facilitates the distribution, documentation, and re-use of scientific components and libraries.« less

  20. Distributed On-line Monitoring System Based on Modem and Public Phone Net

    NASA Astrophysics Data System (ADS)

    Chen, Dandan; Zhang, Qiushi; Li, Guiru

    In order to solve the monitoring problem of urban sewage disposal, a distributed on-line monitoring system is proposed. By introducing dial-up communication technology based on Modem, the serial communication program can rationally solve the information transmission problem between master station and slave station. The realization of serial communication program is based on the MSComm control of C++ Builder 6.0.The software includes real-time data operation part and history data handling part, which using Microsoft SQL Server 2000 for database, and C++ Builder6.0 for user interface. The monitoring center displays a user interface with alarm information of over-standard data and real-time curve. Practical application shows that the system has successfully accomplished the real-time data acquisition from data gather station, and stored them in the terminal database.

  1. Mod3DMT and EMTF: Free Software for MT Data Processing and Inversion

    NASA Astrophysics Data System (ADS)

    Egbert, G. D.; Kelbert, A.; Meqbel, N. M.

    2017-12-01

    "ModEM" was developed at Oregon State University as a modular system for inversion of electromagnetic (EM) geophysical data (Egbert and Kelbert, 2012; Kelbert et al., 2014). Although designed for more general (frequency domain) EM applications, and originally intended as a testbed for exploring inversion search and regularization strategies, our own initial uses of ModEM were for 3-D imaging of the deep crust and upper mantle at large scales. Since 2013 we have offered a version of the source code suitable for 3D magnetotelluric (MT) inversion on an "as is, user beware" basis for free for non-commercial applications. This version, which we refer to as Mod3DMT, has since been widely used by the international MT community. Over 250 users have registered to download the source code, and at least 50 MT studies in the refereed literature, covering locations around the globe at a range of spatial scales, cite use of ModEM for 3D inversion. For over 30 years I have also made MT processing software available for free use. In this presentation, I will discuss my experience with these freely available (but perhaps not truly open-source) computer codes. Although users are allowed to make modifications to the codes (on conditions that they provide a copy of the modified version) only a handful of users have tried to make any modification, and only rarely are modifications even reported, much less provided back to the developers.

  2. Peak Satellite-to-Earth Data Rates Derived From Measurements of a 20 Gbps Bread-Board Modem

    NASA Technical Reports Server (NTRS)

    Landon, David G.; Simons, Rainee N.; Wintucky, Edwin G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen A.; McIntire, William K.; Metz, John L.; Smith, Francis J.

    2011-01-01

    A prototype data link using a Ka-band space qualified, high efficiency 200 W TWT amplifier and a bread-board modem emulator were created to explore the feasibility of very high speed communications in satellite-to-earth applications. Experiments were conducted using a DVB-S2-like waveform with modifications to support up to 20 Gbps through the addition of 128-Quadrature Amplitude Modulation (QAM). Limited by the bandwidth of the amplifier, a constant peak symbol rate of 3.2 Giga-symbols/sec was selected and the modulation order was varied to explore what peak data rate might be supported by an RF link through this amplifier. Using 128-QAM, an implementation loss of 3 dB was observed at 20 Gbps, and the loss decreased as data rate or bandwidth were reduced. Building on this measured data, realistic link budget calculations were completed. Low-Earth orbit (LEO) missions based on this TWTA with reasonable hardware assumptions and antenna sizing are found to be bandwidth-limited, rather than power-limited, making the spectral efficiency of 9/10-rate encoded 128-QAM very attractive. Assuming a bandwidth allocation of 1 GHz, these computations indicate that low-Earth orbit vehicles could achieve data rates up to 5 Gbps-an order of magnitude beyond the current state-of-practice, yet still within the processing power of a current FPGA-based software-defined modem. The measured performance results and a description of the experimental setup are presented to support these conclusions.

  3. Benthic microbial fuel cell as direct power source for an acoustic modem and seawater oxygen/temperature sensor system.

    PubMed

    Gong, Yanming; Radachowsky, Sage E; Wolf, Michael; Nielsen, Mark E; Girguis, Peter R; Reimers, Clare E

    2011-06-01

    Supported by the natural potential difference between anoxic sediment and oxic seawater, benthic microbial fuel cells (BMFCs) promise to be ideal power sources for certain low-power marine sensors and communication devices. In this study a chambered BMFC with a 0.25 m(2) footprint was used to power an acoustic modem interfaced with an oceanographic sensor that measures dissolved oxygen and temperature. The experiment was conducted in Yaquina Bay, Oregon over 50 days. Several improvements were made in the BMFC design and power management system based on lessons learned from earlier prototypes. The energy was harvested by a dynamic gain charge pump circuit that maintains a desired point on the BMFC's power curve and stores the energy in a 200 F supercapacitor. The system also used an ultralow power microcontroller and quartz clock to read the oxygen/temperature sensor hourly, store data with a time stamp, and perform daily polarizations. Data records were transmitted to the surface by the acoustic modem every 1-5 days after receiving an acoustic prompt from a surface hydrophone. After jump-starting energy production with supplemental macroalgae placed in the BMFC's anode chamber, the average power density of the BMFC adjusted to 44 mW/m(2) of seafloor area which is better than past demonstrations at this site. The highest power density was 158 mW/m(2), and the useful energy produced and stored was ≥ 1.7 times the energy required to operate the system.

  4. 15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... forensics (v) Cryptographic accelerator (vi) Data backup and recovery (vii) Database (viii) Disk/drive... (MAN) (xxii) Modem (xxiii) Network convergence or infrastructure n.e.s. (xxiv) Network forensics (xxv...

  5. 15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... forensics (v) Cryptographic accelerator (vi) Data backup and recovery (vii) Database (viii) Disk/drive... (MAN) (xxii) Modem (xxiii) Network convergence or infrastructure n.e.s. (xxiv) Network forensics (xxv...

  6. 15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... forensics (v) Cryptographic accelerator (vi) Data backup and recovery (vii) Database (viii) Disk/drive... (MAN) (xxii) Modem (xxiii) Network convergence or infrastructure n.e.s. (xxiv) Network forensics (xxv...

  7. 15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... forensics (v) Cryptographic accelerator (vi) Data backup and recovery (vii) Database (viii) Disk/drive... (MAN) (xxii) Modem (xxiii) Network convergence or infrastructure n.e.s. (xxiv) Network forensics (xxv...

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Busbey, A.B.

    A number of methods and products, both hardware and software, to allow data exchange between Apple Macintosh computers and MS-DOS based systems. These included serial null modem connections, MS-DOS hardware and/or software emulation, MS-DOS disk-reading hardware and networking.

  9. Modems and More: The Computer Branches Out.

    ERIC Educational Resources Information Center

    Dyrli, Odvard Egil

    1986-01-01

    Surveys new "peripherals," electronic devices that attach to computers. Devices such as videodisc players, desktop laser printers, large screen projectors, and input mechanisms that circumvent the keyboard dramatically expand the computer's instructional uses. (Author/LHW)

  10. 17 CFR 250.21 - Filing of documents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20549. Except as otherwise provided by the rules, such documents shall be deemed to have been filed with... direct transmission, via dial-up modem or Internet. (2) The date of filing of documents shall be...

  11. 17 CFR 250.21 - Filing of documents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20549. Except as otherwise provided by the rules, such documents shall be deemed to have been filed with... direct transmission, via dial-up modem or Internet. (2) The date of filing of documents shall be...

  12. Network Solutions.

    ERIC Educational Resources Information Center

    Vietzke, Robert; And Others

    1996-01-01

    This special section explains the latest developments in networking technologies, profiles school districts benefiting from successful implementations, and reviews new products for building networks. Highlights include ATM (asynchronous transfer mode), cable modems, networking switches, Internet screening software, file servers, network management…

  13. Building vibrations induced by noise from rotorcraft and propeller aircraft flyovers

    NASA Technical Reports Server (NTRS)

    Shepherd, Kevin P.; Hubbard, Harvey H.

    1992-01-01

    Noise and building vibrations were measured for a series of helicopter and propeller-driven aircraft flyovers at WFF during May 1978. The building response data are compared with similar data acquired earlier at sites near Dulles and Kennedy Airports for operation of commercial jet transports, including the Concorde supersonic transport. Results show that noise-induced vibration levels in windows and walls are directly proportional to sound pressure level and that for a given noise level, the acceleration levels induced by a helicopter or a propeller-driven aircraft flyover cannot be distinguished from the acceleration levels induced by a commercial jet transport flyover. Noise-induced building acceleration levels were found to be lower than those levels which might be expected to cause structural damage and were also lower than some acceleration levels induced by such common domestic events as closing windows and doors.

  14. Carrier recovery methods for a dual-mode modem: A design approach

    NASA Technical Reports Server (NTRS)

    Richards, C. W.; Wilson, S. G.

    1984-01-01

    A dual mode model with selectable QPSK or 16-QASK modulation schemes is discussed. The theoretical reasoning as well as the practical trade-offs made during the development of a modem are presented, with attention given to the carrier recovery method used for coherent demodulation. Particular attention is given to carrier recovery methods that can provide little degradation due to phase error for both QPSK and 16-QASK, while being insensitive to the amplitude characteristic of a 16-QASK modulation scheme. A computer analysis of the degradation is symbol error rate (SER) for QPSK and 16-QASK due to phase error is prresented. Results find that an energy increase of roughly 4 dB is needed to maintain a SER of 1X10(-5) for QPSK with 20 deg of phase error and 16-QASK with 7 deg phase error.

  15. The work of Galileo and conformation of the experiment in physics

    NASA Astrophysics Data System (ADS)

    Alvarez, J. L.; Posadas, Y.

    2003-02-01

    It is very frequent to find comments and references to Galileo's work suggesting that he based his affirmations on a logic thought and not on observations. In this paper we present an analysis of some experiments that he realized and were unknown in the XVI and XVII centuries; in they we find a clear description of the methodology that Galileo follows in order to reach the results that he presents in his formal work, particularly in Discorsi. In contrast with the Aristotelian philosophy, in these manuscripts Galileo adopt a methodology with which he obtain great contributions for the modem conformation of the experimental method, founding so a methodology for the study of the movement. We use this analysis as an example of the difficulties that are present in the conformation of the modem experimentation and we point out the necessity to stress the importance of the scientific methodology in the teaching of physics.

  16. ANSYS Modeling of Hydrostatic Stress Effects

    NASA Technical Reports Server (NTRS)

    Allen, Phillip A.

    1999-01-01

    Classical metal plasticity theory assumes that hydrostatic pressure has no effect on the yield and postyield behavior of metals. Plasticity textbooks, from the earliest to the most modem, infer that there is no hydrostatic effect on the yielding of metals, and even modem finite element programs direct the user to assume the same. The object of this study is to use the von Mises and Drucker-Prager failure theory constitutive models in the finite element program ANSYS to see how well they model conditions of varying hydrostatic pressure. Data is presented for notched round bar (NRB) and "L" shaped tensile specimens. Similar results from finite element models in ABAQUS are shown for comparison. It is shown that when dealing with geometries having a high hydrostatic stress influence, constitutive models that have a functional dependence on hydrostatic stress are more accurate in predicting material behavior than those that are independent of hydrostatic stress.

  17. A mixed-modem approach to data isolation on a broadband local area network

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Crutcher, R.I.; Ewing, P.D.

    1988-01-01

    Data isolation is required to broadband networks to prevent unauthorized access to the sensitive data of other users. Isolation can be obtained by using equipment from more than one manufacturer to introduce incompatibility between nonassociated users. This paper develops the basis for isolation and postulates that four layers of isolation will exist when the proper equipment is chosen. An experimental broadband local area network (LAN) was constructed to verify isolation. This independent network allowed variations in operating conditions without causing interference in normal broadband operations. The measured results indicate that a broadband LAN can transmit data of varying sensitivity levelsmore » without compromising data security. When combined with certain administrative restrictions, the mixed-modem technique provides a cost-effective method of sharing a broadband network while maintaining isolation of data having different sensitivities. 5 refs., 2 figs.« less

  18. A mixed-modem solution for sensitive data segregation on a broadband network

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Crutcher, R.I.; Ewing, P.D.

    1988-01-01

    Data isolation is required in broadband networks to prevent unauthorized access to the sensitive data of other users. Isolation can be obtained by using equipment from different manufacturers to introduce incompatibility between nonassociated users. This paper develops the basis for isolation and postulates that four layers of ioslation will exist when the proper equipment is chosen. An experimental broadband local area network (LAN) was constructed to verify isolation. This independent test system allowed variations to network operating conditions without causing interference to normal broadband operations. The measured results indicate that a broadband LAN can transmit data of varying sensitivity levelsmore » without compromising data security. When combined with the proper administrative restrictions, the mixed-modem technique provides a cost-effective method of sharing a broadband network while maintaining isolation of data having different sensitivities. 6 refs., 3 figs.« less

  19. REMOTE SENSING AND MOUNTAINTOP MINING

    EPA Science Inventory

    Coal mining is Appalachia has undergone dramatic changes in the past decade. Modem mining practices know as Mountaintop Mining (MTM) and Valley Fills (VF) are at the center of an environmental and legal controversy that has spawned lawsuits and major environmental investigations....

  20. Faster, Better, Cheaper: A Decade of PC Progress.

    ERIC Educational Resources Information Center

    Crawford, Walt

    1997-01-01

    Reviews the development of personal computers and how computer components have changed in price and value. Highlights include disk drives; keyboards; displays; memory; color graphics; modems; CPU (central processing unit); storage; direct mail vendors; and future possibilities. (LRW)

  1. Search Hardware: Latest and Greatest.

    ERIC Educational Resources Information Center

    Alberico, Ralph

    1988-01-01

    Uses the different search environments of information brokers and institutional searchers to illustrate the factors that should be considered when selecting microcomputers for search operations. The factors discussed include speed, storage capabilities, displays, modems, printing technologies, facsimile transmission, and portability. A directory…

  2. A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

    NASA Astrophysics Data System (ADS)

    Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

    2014-12-01

    High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

  3. POTS to broadband ... cable modems.

    PubMed

    Kabachinski, Jeff

    2003-01-01

    There have been 3 columns talking about broadband communications and now at the very end when it's time to compare using a telco or cableco, I'm asking does it really matter? So what if I can actually get the whole 30 Mbps with a cable network when the website I'm connecting to is running on an ISDN line at 128 Kbps? Broadband offers a lot more bandwidth than the connections many Internet servers have today. Except for the biggest websites, many servers connect to the Internet with a switched 56-Kbps, ISDN, or fractional T1 line. Even with the big websites, my home network only runs a 10 Mbps Ethernet connection to my cable modem. Maybe it doesn't matter that the cable lines are shared or that I can only get 8 Mbps from an ADSL line. Maybe the ISP that I use has a T1 line connection to the Internet so my new ADSL modem has a fatter pipe than my provider! (See table 1). It all makes me wonder what's in store for us in the future. PC technology has increased exponentially in the last 10 years with super fast processor speeds, hard disks of hundreds of gigabytes, and amazing video and audio. Internet connection speeds have failed to keep the same pace. Instead of hundreds of times better or faster--modem speeds are barely 10 times faster. Broadband connections offer some additional speed but still not comparable growth as broadband connections are still in their infancy. Rather than trying to make use of existing communication paths, maybe we need a massive infrastructure makeover of something new. How about national wireless access points so we can connect anywhere, anytime? To use the latest and fastest wireless technology you will simply need to buy another $9.95 WLAN card or download the latest super slick WLAN compression/encryption software. Perhaps it is time for a massive infra-restructuring. Consider the past massive infrastructure efforts. The telcos needed to put in their wiring infrastructure starting in the 1870s before telephones were useful to the masses. CATV was a minor player in the TV broadcast business before they installed their cabling infrastructure and went national. Even automobiles were fairly useless until roads were paved and the highway infrastructure was built!

  4. Taiwan’s Transition to Democracy

    DTIC Science & Technology

    1997-03-01

    hard authoritarianism established by Chiang-Kai Shek’s regime allowed the institutions of private property and free enterprise to promote economic ... stability . Rapid growth followed and Taiwan transitioned from an agrarian based economy to a modem industrialized nation. The pressures from economic

  5. Global Networking.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    1997-01-01

    Discusses the state of the Internet. Highlights include the magnitude of the infrastructure, costs, its increasing pace, constraints in international links, provision of network capacity to homes and small businesses, cable television modems, political and cultural problems, the digital library concept, search engines, the failure of personal…

  6. Computer Networks and Networking: A Primer.

    ERIC Educational Resources Information Center

    Collins, Mauri P.

    1993-01-01

    Provides a basic introduction to computer networks and networking terminology. Topics addressed include modems; the Internet; TCP/IP (Transmission Control Protocol/Internet Protocol); transmission lines; Internet Protocol numbers; network traffic; Fidonet; file transfer protocol (FTP); TELNET; electronic mail; discussion groups; LISTSERV; USENET;…

  7. Jargon that Computes: Today's PC Terminology.

    ERIC Educational Resources Information Center

    Crawford, Walt

    1997-01-01

    Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus…

  8. Glossary of Internet Terms.

    ERIC Educational Resources Information Center

    Microcomputers for Information Management, 1995

    1995-01-01

    Provides definitions for 71 terms related to the Internet, including Archie, bulletin board system, cyberspace, e-mail (electronic mail), file transfer protocol, gopher, hypertext, integrated services digital network, local area network, listserv, modem, packet switching, server, telnet, UNIX, WAIS (wide area information servers), and World Wide…

  9. NAS (Host/ARTS) IIIA to VME Modem Interface ATC Interface Hardware Manual

    DOT National Transportation Integrated Search

    1990-10-01

    This document is reference material for personnel using the National Airspace : System (NAS) (HOST or ARTS IIIA) Air Traffic Control (ATC) Interface Subsystem. : It was originally developed to be part of the Data Link Test and Analysis System : (DATA...

  10. Instrumentation to Improve Chemistry and Environmental Science Laboratory Curricula

    DTIC Science & Technology

    1999-09-01

    Introduction of modem chemical instrumentation in the chemistry, biology, and environmental science curricula provides a valuable experience for students and...stimulation for the faculty. The major concern now facing the chemistry, biology, and environmental science faculty at PCUPR is the inability to

  11. The Use of a Microcomputer as an EKG Monitor.

    ERIC Educational Resources Information Center

    Walters, R. A.; Reynolds, R. F.

    1983-01-01

    Discusses the design and operation of a microcomputer system which obtains and displays an individual's electrocardiogram (EKG). The EKG information, in digital form, can be stored on a floppy disk and transmitted over telephone lines by use of a modem. (JN)

  12. Upper Grades Ideas.

    ERIC Educational Resources Information Center

    Thornburg, David; Beane, Pam

    1983-01-01

    Presents programs for creating animated characters (Atari), random sentences (Logo), and making a triangle (TRS-80 Level III Basic), and suggestions for creative writing and comparison shopping for computers/software. Also includes "Modems for Micros: Your Computer Can Talk on the Phone" (Bill Chalgren) on telecommunications capabilities of…

  13. 77 FR 24178 - Information Systems Technical Advisory Committee; Notice of Partially Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... and Introductions 2. Working Group Reports 3. Industry Presentation: E-beam Lithography 4. Industry Presentation: ENC Threshold for Satellite Modem 5. Industry Presentation: Semiconductor Manufacturing Equipment... DEPARTMENT OF COMMERCE Bureau of Industry and Security Information Systems Technical Advisory...

  14. Alternative treatment technology information center computer database system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sullivan, D.

    1995-10-01

    The Alternative Treatment Technology Information Center (ATTIC) computer database system was developed pursuant to the 1986 Superfund law amendments. It provides up-to-date information on innovative treatment technologies to clean up hazardous waste sites. ATTIC v2.0 provides access to several independent databases as well as a mechanism for retrieving full-text documents of key literature. It can be accessed with a personal computer and modem 24 hours a day, and there are no user fees. ATTIC provides {open_quotes}one-stop shopping{close_quotes} for information on alternative treatment options by accessing several databases: (1) treatment technology database; this contains abstracts from the literature on all typesmore » of treatment technologies, including biological, chemical, physical, and thermal methods. The best literature as viewed by experts is highlighted. (2) treatability study database; this provides performance information on technologies to remove contaminants from wastewaters and soils. It is derived from treatability studies. This database is available through ATTIC or separately as a disk that can be mailed to you. (3) underground storage tank database; this presents information on underground storage tank corrective actions, surface spills, emergency response, and remedial actions. (4) oil/chemical spill database; this provides abstracts on treatment and disposal of spilled oil and chemicals. In addition to these separate databases, ATTIC allows immediate access to other disk-based systems such as the Vendor Information System for Innovative Treatment Technologies (VISITT) and the Bioremediation in the Field Search System (BFSS). The user may download these programs to their own PC via a high-speed modem. Also via modem, users are able to download entire documents through the ATTIC system. Currently, about fifty publications are available, including Superfund Innovative Technology Evaluation (SITE) program documents.« less

  15. Evolution of the Water Balance of an Urban Catchment (Extended Abst)

    EPA Science Inventory

    The 20th century marked the emergence of the modem American City and its complex extensive infrastructure for supplying drinking water, treating wastewater and managing storm water. During this period of intense urban development, unintentional mismanagement of the urban water ba...

  16. Telecommunications: Working To Enhance Global Understanding and Peace Education.

    ERIC Educational Resources Information Center

    Schrum, Lynne M.

    This paper describes educational activities that make use of microcomputers and information networks to link elementary and secondary students electronically using telecommunications, i.e., communication across distances using personal computers, modems, telephone lines, and computer networks. Efforts to promote global understanding and awareness…

  17. Telecommunication for the Physically Handicapped.

    ERIC Educational Resources Information Center

    Cunningham, Pat; Gose, Joan

    The paper examines the uses of telecommunication for physically handicapped students. Basic equipment, including a modem and keyboard interface, are described. The types and uses of computer bulletin boards are also described. Among benefits of telecommunications for physically handicapped students noted in the paper are social prestige,…

  18. 76 FR 5824 - In the Matter of Certain Mobile Telephones and Modems; Notice of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ... Act of 1930, as amended, 19 U.S.C. 1337, on behalf of Sony Corporation of Japan. The complaint alleges... shall be served: (a) The complainant is: Sony Corporation, 1-7-1 Konan, Minato-ku, Tokyo, 108-0075...

  19. Mechanistic Indicators of Childhood Asthma (MICA): piloting an integrative design for evaluating environmental health

    EPA Science Inventory

    Background: Modem methods in molecular biology and advanced computational tools show promise in elucidating complex interactions that occur between genes and environmental factors in diseases such as asthma; however appropriately designed studies are critical for these methods to...

  20. Digital synchronization and communication techniques

    NASA Technical Reports Server (NTRS)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  1. Army Medical Imaging System - ARMIS

    DTIC Science & Technology

    1992-08-08

    modems , scanners, hard disk drives, dot matrix printers, erasable-optical disc drives, CD-ROM drives, WORM disc drives and tape drives are fully...can use 56K leased lines, TI links, digital data circuits, or public telephone lines. 3. ISDN The Integrated Services Digital Network, ISDN, is a

  2. The Remote Analysis Station (RAS) as an instructional system

    NASA Technical Reports Server (NTRS)

    Rogers, R. H.; Wilson, C. L.; Dye, R. H.; Jaworski, E.

    1981-01-01

    "Hands-on" training in LANDSAT data analysis techniques can be obtained using a desk-top, interactive remote analysis station (RAS) which consists of a color CRT imagery display, with alphanumeric overwrite and keyboard, as well as a cursor controller and modem. This portable station can communicate via modem and dial-up telephone with a host computer at 1200 baud or it can be hardwired to a host computer at 9600 baud. A Z80 microcomputer controls the display refresh memory and remote station processing. LANDSAT data is displayed as three-band false-color imagery, one-band color-sliced imagery, or color-coded processed imagery. Although the display memory routinely operates at 256 x 256 picture elements, a display resolution of 128 x 128 can be selected to fill the display faster. In the false color mode the computer packs the data into one 8-bit character. When the host is not sending pictorial information the characters sent are in ordinary ASCII code. System capabilities are described.

  3. New directions in the history of modern science in China: global science and comparative history.

    PubMed

    Elman, Benjamin A

    2007-09-01

    These essays collectively present new perspectives on the history of modem science in China since 1900. Fa-ti Fan describes how science under the Republic of China after 1911 exhibited a complex local and international character that straddled both imperialism and colonialism. Danian Hu focuses on the fate of relativity in the physics community in China after 1917. Zuoyue Wang hopes that a less nationalist political atmosphere in China will stimulate more transnational studies of modern science, which will in turn reveal the underlying commonalities in different national contexts. Sigrid Schmalzer compares the socialist and the capitalist contexts for science in China and reopens the sensitive question of the "mass line" during the Cultural Revolution. Grace Shen describes the tensions early Chinese scientists felt when choosing between foreign models for modem geology and their own professional identities in China. Taken together, these accounts present us with a comparative history of modern science in China that is both globally and locally informed.

  4. HSDPA (3.5G)-based ubiquitous integrated biotelemetry system for emergency care.

    PubMed

    Kang, Jaemin; Shin, Il Hyung; Koo, Yoonseo; Jung, Min Yang; Suh, Gil Joon; Kim, Hee Chan

    2007-01-01

    We have developed the second prototype system of Ubiquitous Integrated Biotelemetry System for Emergency Care(UIBSEC) using a HSDPA(High Speed Downlink Packet Access) modem to be used by emergency rescuers to get directions from medical doctors in providing emergency medical services for patients in ambulance. Five vital bio-signal instrumentation modules have been implemented, which include noninvasive arterial blood pressure (NIBP), arterial oxygen saturation (SaO2), 6-channel electro-cardiogram(ECG), blood glucose level, and body temperature and real-time motion picture of the patient and GPS information are also taken. Measured patient data, captured motion picture and GPS information are then transferred to a doctor's PC through the HSDPA and TCP/IP networks using stand-alone HSDPA modem. Most prominent feature of the developed system is that it is based on the HSDPA backbone networks available in Korea now, through which we will be able to establish a ubiquitous emergency healthcare service system.

  5. Telemetric system for hydrology and water quality monitoring in watersheds of northern New Mexico, USA.

    PubMed

    Meyer, Michael L; Huey, Greg M

    2006-05-01

    This study utilized telemetric systems to sample microbes and pathogens in forest, burned forest, rangeland, and urban watersheds to assess surface water quality in northern New Mexico. Four sites included remote mountainous watersheds, prairie rangelands, and a small urban area. The telemetric system was linked to dataloggers with automated event monitoring equipment to monitor discharge, turbidity, electrical conductivity, water temperature, and rainfall during base flow and storm events. Site data stored in dataloggers was uploaded to one of three types of telemetry: 1) radio in rangeland and urban settings; 2) a conventional phone/modem system with a modem positioned at the urban/forest interface; and 3) a satellite system used in a remote mountainous burned forest watershed. The major variables affecting selection of each system were site access, distance, technology, and cost. The systems were compared based on operation and cost. Utilization of telecommunications systems in this varied geographic area facilitated the gathering of hydrologic and water quality data on a timely basis.

  6. Adaptive and reliably acknowledged FSO communications

    NASA Astrophysics Data System (ADS)

    Fitz, Michael P.; Halford, Thomas R.; Kose, Cenk; Cromwell, Jonathan; Gordon, Steven

    2015-05-01

    Atmospheric turbulence causes the receive signal intensity on free space optical (FSO) communication links to vary over time. Scintillation fades can stymie connectivity for milliseconds at a time. To approach the information-theoretic limits of communication in such time-varying channels, it necessary to either code across extremely long blocks of data - thereby inducing unacceptable delays - or to vary the code rate according to the instantaneous channel conditions. We describe the design, laboratory testing, and over-the-air testing of an FSO modem that employs a protocol with adaptive coded modulation (ACM) and hybrid automatic repeat request. For links with fixed throughput, this protocol provides a 10dB reduction in the required received signal-to-noise ratio (SNR); for links with fixed range, this protocol provides the greater than a 3x increase in throughput. Independent U.S. Government tests demonstrate that our protocol effectively adapts the code rate to match the instantaneous channel conditions. The modem is able to provide throughputs in excess of 850 Mbps on links with ranges greater than 15 kilometers.

  7. Tides and Modern Geodesy

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

    2002-01-01

    In modem high-precision geodesy, and especially in modem space geodesy, every measurement that one makes contains tidal signals. Generally these signals are considered noise and must somehow be eliminated. The stringent requirements of the latest space geodetic missions place severe demands on tidal models. On the other hand, these missions provide the strongest data for improving tidal models. In particular, TOPEX/POSEIDON altimetry and LAGEOS laser ranging have improved models to such an extent that new geophysical information about the ocean and the solid Earth are coming to light. Presumably GRACE intersatellite ranging data will also add to this information. This paper discusses several of these new geophysical results, with special emphasis given to the dissipation of tidal energy. Strong constraints have recently been placed on the partitioning of energy dissipation among the ocean, atmosphere, and solid earth and between the deep and shallow ocean. The dissipation in deep water is associated with internal tides and has potentially important implications for understanding the ocean's thermohaline circulation.

  8. ITC/USA/'82; Proceedings of the International Telemetering Conference, San Diego, CA, September 28-30, 1982

    NASA Astrophysics Data System (ADS)

    The topics studied are related to customer-designed integrated circuits and silicon foundries, systems applications, recent developments in airborne telemetry hardware, optical communications, theoretical applications, stored data systems, digital communications-satellites and other systems, antenna systems and technology, the AF satellite control network, modems, telemetry standards, NASA Deep Space Network operations, and modems applicable to range telemetry and range data relay. Aspects of communication interoperability and transmission standards are considered along with subjects of magnetic tape rec/rep theory and technology, a satellite command and control panel, a computer automated ground station, STS communications, cryptography, RF systems, sensor unique data recovery techniques, software applications, multiplexer-demuliplexer, microprocessor applications, and communication relays. Attention is given to the U.S. Federal data encryption standard (DES), the impact of channel errors on data compression, the effect of premodulation filters on bit error rate performance, and power efficient optical communications for space applications. For individual items see A84-32402 to A84-32456

  9. Modeling And Simulation Of Electrical Prevenion System Using Arduino Uno,Gsm Modem, And Acs712 Current Sensor

    NASA Astrophysics Data System (ADS)

    Khair, Ummul; Jabbar Lubis, Abdul; Agustha, Indra; Dharmawati; Zulfin, M.

    2017-12-01

    The current electricity needs is very primary, all objects including electronics require power, it encourages people not to be able to save electricity so the theft of electric power would be done. The use of ACS712 current sensor as the sensor with arduino uno would find out the power consumption continuously and prevent the theft of electricity because of the use of electricity which has been determined by PLN and the people fetl that it is not enough for every house, so the author made a tool for prevention of theft of electric power by using the arduino uno, buzzer, ACS712 current sensor, lcd, and relay then the power usage can be controlled according to the use to prevent the occurrence of theft of electricity so the use can be seen directly on the lcd 16x2and GSM modem to give information to employees of PLN so that it can reduceelectrical theft by the public.

  10. Remote monitoring of sub ppb levels of vinyl chloride, dichloroethylene and trichloroethylene via modem operated automated GC

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Linenberg, A.; Lander, N.J.

    1994-12-31

    The need for remote monitoring of certain compounds in a sparsely populated area with limited user assistance led to the development and manufacture of a self contained, portable gas chromatography with the appropriate software. Part per billion levels of vinyl chloride, cis 1,2 dichloroethylene and trichloroethylene were detected in air using a trap for preconcentration of the compounds. The units were continuously calibrated with certified standards from Scott Specialty Gases, which in one case was 1 part per billion of the aforementioned compounds. The entire operation of the units, including monitoring instrument responses, changing operating parameters, data transfer, data reviewmore » and data reporting was done entirely on a remote basis from approximately 600 miles away using a remote computer with a modem and remote operating software. The entire system concept promises the availability of highly sensitive remote monitoring in sparsely populated areas for long periods of time.« less

  11. A Software Upgrade of the NASA Aeroheating Code "MINIVER"

    NASA Technical Reports Server (NTRS)

    Louderback, Pierce Mathew

    2013-01-01

    Computational Fluid Dynamics (CFD) is a powerful and versatile tool simulating fluid and thermal environments of launch and re-entry vehicles alike. Where it excels in power and accuracy, however, it lacks in speed. An alternative tool for this purpose is known as MINIVER, an aeroheating code widely used by NASA and within the aerospace industry. Capable of providing swift, reasonably accurate approximations of the fluid and thermal environment of launch vehicles, MINIVER is used where time is of the essence and accuracy need not be exact. However, MINIVER is an old, aging tool: running on a user-unfriendly, legacy command-line interface, it is difficult for it to keep pace with more modem software tools. Florida Institute of Technology was tasked with the construction of a new Graphical User Interface (GUI) that implemented the legacy version's capabilities and enhanced them with new tools and utilities. This thesis provides background to the legacy version of the program, the progression and final version of a modem user interface, and benchmarks to demonstrate its usefulness.

  12. Parallel digital modem using multirate digital filter banks

    NASA Technical Reports Server (NTRS)

    Sadr, Ramin; Vaidyanathan, P. P.; Raphaeli, Dan; Hinedi, Sami

    1994-01-01

    A new class of architectures for an all-digital modem is presented in this report. This architecture, referred to as the parallel receiver (PRX), is based on employing multirate digital filter banks (DFB's) to demodulate, track, and detect the received symbol stream. The resulting architecture is derived, and specifications are outlined for designing the DFB for the PRX. The key feature of this approach is a lower processing rate then either the Nyquist rate or the symbol rate, without any degradation in the symbol error rate. Due to the freedom in choosing the processing rate, the designer is able to arbitrarily select and use digital components, independent of the speed of the integrated circuit technology. PRX architecture is particularly suited for high data rate applications, and due to the modular structure of the parallel signal path, expansion to even higher data rates is accommodated with each. Applications of the PRX would include gigabit satellite channels, multiple spacecraft, optical links, interactive cable-TV, telemedicine, code division multiple access (CDMA) communications, and others.

  13. A TMS320-based modem for the aeronautical-satellite core data service

    NASA Astrophysics Data System (ADS)

    Moher, Michael L.; Lodge, John H.

    The International Civil Aviation Organization (ICAO) Future Air Navigation Systems (FANS) committee, the Airlines Electronics Engineering Committee (AEEC), and Inmarsat have been developing standards for an aeronautical satellite communications service. These standards encompass a satellite communications system architecture to provide comprehensive aeronautical communications services. Incorporated into the architecture is a core service capability, providing only low rate data communications, which all service providers and all aircraft earth terminals are required to support. In this paper an implementation of the physical layer of this standard for the low data rate core service is described. This is a completely digital modem (up to a low intermediate frequency). The implementation uses a single TMS320C25 chip for the transmit baseband functions of scrambling, encoding, interleaving, block formatting and modulation. The receiver baseband unit uses a dual processor configuration to implement the functions of demodulation, synchronization, de-interleaving, decoding and de-scrambling. The hardware requirements, the software structure and the algorithms of this implementation are described.

  14. FIREDOC users manual, 3rd edition

    NASA Astrophysics Data System (ADS)

    Jason, Nora H.

    1993-12-01

    FIREDOC is the on-line bibliographic database which reflects the holdings (published reports, journal articles, conference proceedings, books, and audiovisual items) of the Fire Research Information Services (FRIS) at the Building and Fire Research Laboratory (BFRL), National Institute of Standards and Technology (NIST). This manual provides step-by-step procedures for entering and exiting the database via telecommunication lines, as well as a number of techniques for searching the database and processing the results of the searches. This Third Edition is necessitated by the change to a UNIX platform. The new computer allows for faster response time if searching via a modem and, in addition, offers internet accessibility. FIREDOC may be used with personal computers, using DOS or Windows, or with Macintosh computers and workstations. A new section on how to access Internet is included, and one on how to obtain the references of interest to you. Appendix F: Quick Guide to Getting Started will be useful to both modem and Internet users.

  15. Software Reviews: Programs Worth a Second Look.

    ERIC Educational Resources Information Center

    Olds, Henry F., Jr.; And Others

    1988-01-01

    Examines four software packages: (1) "Wordbench"--writing and word processing, grades 9-12 (IBM and Apple); (2) "Muppet Slate"--language arts, grades K-2 (Apple); (3) "Accu-Weather Forecaster"--weather analysis and forecasting, grades 3-12 (modem with IBM or Mac); and (4) "The Ripple That Changed American…

  16. Hypoxia Hotspots in the Mississippi Bight

    DTIC Science & Technology

    2006-04-01

    settings (see Sen Gupta and Machain- Pyrite framboid size and size distribution have been used Castillo , 1993, and references therein; Grantham and as...today/lASNFS-gom.html#msb. (eds.), Modem and Ancient Continental Shelf Anoxia: Geological NELSEN, T. A., BLACKWELDER, P., HOOD, T., MCKEE, B., ROMER , N

  17. Air Traffic Control Experimentation and Evaluation with the NASA ATS-6 Satellite : Volume 4. Data Reduction and Analysis Software.

    DOT National Transportation Integrated Search

    1976-09-01

    Software used for the reduction and analysis of the multipath prober, modem evaluation (voice, digital data, and ranging), and antenna evaluation data acquired during the ATS-6 field test program is described. Multipath algorithms include reformattin...

  18. The 10 Hottest Technologies in Telecom.

    ERIC Educational Resources Information Center

    Flanagan, Patrick

    1996-01-01

    Synthesizes opinions of experts regarding technologies deemed most likely to enter the telecommunications mainstream by 1998, including: (1) the Java programming language; (2) voice- over frame relay; (3) virtual local area networks (LANs); (4) cable modems; (5) gigabit LANs; (6) Internet appliances; (7) personal satellite phones; (8) intranets;…

  19. The Salmonella Mutagenicity Assay: The Stethoscope of Genetic Toxicology for the 21 st Century

    EPA Science Inventory

    OBJECTIVES: According to the 2007 National Research Council report Toxicology for the Twenty-first Century, modem methods ("omics," in vitro assays, high-throughput testing, computational methods, etc.) will lead to the emergence of a new approach to toxicology. The Salmonella ma...

  20. Join This Cool Club!

    ERIC Educational Resources Information Center

    Novelli, Joan

    1995-01-01

    Students can study the Arctic by creating Arctic clubs, using modems to communicate with students nationwide who are following International Arctic Project (IAP) explorers. The article describes the IAP, explains how to form a club, and discusses issues that clubs can tackle, for example, pollution, Arctic animals, natural resources, and the…

  1. Potential capabilities of lunar laser ranging for geodesy and relativity

    NASA Technical Reports Server (NTRS)

    Muller, Jurgen; Williams, James G.; Turshev, Slava G.; Shelus, Peter J.

    2005-01-01

    Here, we review the LLR technique focusing on its impact on Geodesy and Relativity. We discuss the modem observational accuracy and the level of existing LLR modeling. We present the near-term objectives and emphasize improvements needed to fully utilize the scientific potential of LLR.

  2. 7 CFR 1755.405 - Voiceband data transmission measurements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Voiceband data transmission measurements. 1755.405..., AND STANDARD CONTRACT FORMS § 1755.405 Voiceband data transmission measurements. (a) The data... nonloaded subscriber loop circuits for data modem transmission. (b) Signal-to-C notched noise (S/CNN...

  3. Air Force SBIR/STTR Advantage. 2nd Quarter, 2011

    DTIC Science & Technology

    2011-01-01

    modem military aircraft. One structure of particular concern is the vertical stabilizer of the F-15 aircraft, with the bonding between the boron/ epoxy ...fiber brushes are currently deployed in the U.S. Navy submarine fleet in critical nuclear propulsion plant components on three separate submarine

  4. Presenting the Rain-Sea Interaction Facility

    NASA Technical Reports Server (NTRS)

    Bliven, Larry F.; Elfouhaily, Tonas M.

    1993-01-01

    The new Rain-Sea Interaction Facility (RSIF) was established at GSFC/WFF and the first finds are presented. The unique feature of this laboratory is the ability to systematically study microwave scattering from a water surface roughened by artificial rain, for which the droplets are at terminal velocity. The fundamental instruments and systems (e.g., the rain simulator, scatterometers, and surface elevation probes) were installed and evaluated during these first experiments - so the majority of the data were obtained with the rain simulator at 1 m above the water tank. From these initial experiments, three new models were proposed: the square-root function for NCS vs. R, the log Gaussian model for ring-wave elevation frequency spectrum, and the Erland probability density distribution for back scattered power. Rain rate is the main input for these models, although the coefficients may be dependent upon other factors (drop-size distribution, fall velocity, radar configuration, etc.). The facility is functional and we foresee collaborative studies with investigators who are engaged in measuring and modeling rain-sea interaction processes.

  5. Prime Contractors with Awards Over $25,000 by Name, Location, and Contract Number, Fiscal Year 87. Part 6. HI Desert Eagle Corporation-Kingsley Machine Company, Incorporated.

    DTIC Science & Technology

    1987-01-01

    a a . c - 4 ) ) x’ m~ a4 a. a a J~C 0. ~a.L a. a m ac zz acca > a0 0 a0 a 0o~ a a 7- .CLa - cF 4 0 - HH u H auH. z~ -a a A wa a a~~~ a w .Laa.4 w...FF cc>C ~ ~ ~ ~ F o F ,.FF X1 F F -C F) F F -IC 0~~ 3 F F F3 Lo3F< 4 FF 4 0 F F . F 0 F 4 F * 0 0 OFUF 0 C 0 1 F CZFCi F7 Zl F C ,O D O C F - F F F...8217. ZU)to -At-4 - ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ k OD.-.-- - - - - - -.. -. . .~- - - r ~rwr y vva v- - - .3l f3 . ~ r.- (SOc Cr J m- OD( N t--C m m

  6. Plus Ca Change: Minitel and Teletel, Electronic Marvels with Language Teaching Potential.

    ERIC Educational Resources Information Center

    Carney, William J.

    The impact and cultural implications of the French Minitel and Teletel system are discussed, and second language clasroom applications are examined. These electronic instruments were developed for nationwide transmission of computerized data using small television-like terminals connected by modem to existing telephone circuits. Wise marketing…

  7. Teacher Education--Online.

    ERIC Educational Resources Information Center

    Leach, Jenny

    1996-01-01

    The Open University of United Kingdom's Postgraduate Certificate of Education program is an 18-month, part-time course that annually trains over 1000 graduate teachers via electronic conferencing and open learning methods. The program provides every student and tutor with a Macintosh computer, printer, and modem and builds on face-to-face contacts…

  8. MECHANISTIC INDICATORS OF CHILDHOOD ASTHMA (MICA): A SYSTEMS BIOLOGY APPROACH FOR THE INTEGRATION OF MULTIFACTORIAL EXPOSURE AND ENVIRONMENTAL HEALTH DATA

    EPA Science Inventory

    Modem methods in molecular biology and advanced computational tools show promise in elucidating complex interactions that occur between genes and environmental factors in diseases such as asthma. However, appropriately designed studies are critical for these methods to reach the...

  9. Waves and the Equilibrium Range at Ocean Weather Station P

    DTIC Science & Technology

    2013-11-08

    spectral moments are computed onboard. The spectra are transmitted via Iridium satellite modem to the Coastal Data Information Program ( CDIP ) at the...Julie Thomas and Grant Cameron ( CDIP -SIO) provided the waverider data telemetry and data archiving. Wind data were provided by the PMEL-NOAA Ocean

  10. AUV-12 Sonar Integration and Evaluation

    DTIC Science & Technology

    2010-02-26

    ActiveX control allow the real-time ES MKII data (with embedded navigation data) to be logged to the SBC disk in the ES MKII native XTF format. We...begin transmission to the AUV via the acoustic micro-modem message type 28 that contains the target vessel position, true heading, course over

  11. COSMOS (County of San Mateo Online System). A Searcher's Manual.

    ERIC Educational Resources Information Center

    San Mateo County Superintendent of Schools, Redwood City, CA. Educational Resources Center.

    Operating procedures are explained for COSMOS (County of San Mateo Online System), a computerized information retrieval system designed for the San Mateo Educational Resources Center (SMERC), which provides interactive access to both ERIC and a local file of fugitive documents. COSMOS hardware and modem compatibility requirements are reviewed,…

  12. The Electronic Diary: The Technologization of the Personal.

    ERIC Educational Resources Information Center

    Desser, Daphne

    With each technological advancement--telephone, automobile, television, and modem--people gain convenience, efficiency, and speed; they lose immediacy, real as opposed to virtual community, and physicality. At a writer's computer conference, journal writers who have used a diary with a lock and key to keep writings private wonder how to reconcile…

  13. Aerial Networking for the Implementation of Cooperative Control on Small Unmanned Aerial Systems

    DTIC Science & Technology

    2013-03-01

    the relay aircraft to an optimal location. Secondly, a mesh network was configured and tested. This configuration successfully relayed aircraft...functionality, such as updating navigation waypoints to each aircraft. The results suggest the system be updated with more capable modems in a mesh ...

  14. 17 CFR 232.12 - Business hours of the Commission.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Business hours of the Commission. 232.12 Section 232.12 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... documents may be submitted by direct transmission, via dial-up modem or Internet, to the Commission each day...

  15. 17 CFR 232.12 - Business hours of the Commission.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Business hours of the Commission. 232.12 Section 232.12 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... documents may be submitted by direct transmission, via dial-up modem or Internet, to the Commission each day...

  16. Pre-Employment Testing on the Internet: Put Candidates a Click Away and Hire at Modem Speed.

    ERIC Educational Resources Information Center

    Mooney, John

    2002-01-01

    The experience of a county government illustrates factors to consider in implementing online employment testing for job candidates: (1) selection of the appropriate Internet-based test; (2) passwords, timing, security, and technical difficulties; and (3) provisions for applicants who lack Internet access. (SK)

  17. The Electronic Classroom.

    ERIC Educational Resources Information Center

    Mizell, Al P.; Centini, Barry M.

    The role of telecommunications in establishing the electronic classroom in distance education is illustrated. Using a computer-based doctoral program and the UNIX operating system as an example, how a personal computer and modem may be combined with a telephone line for instructional delivery is described. A number of issues must be addressed in…

  18. Tethered acoustic doppler current profiler platforms for measuring streamflow

    USGS Publications Warehouse

    Rehmel, Michael S.; Stewart, James A.; Morlock, Scott E.

    2003-01-01

    A tethered-platform design with a trimaran hull and 900-megahertz radio modems is now commercially available. Continued field use has resulted in U.S. Geological Survey procedures for making tethered-platform discharge measurements, including methods for tethered-boat deployment, moving-bed tests, and measurement of edge distances.

  19. Add-Ons: The Ultimate Guide to Peripherals for the Blind Computer User.

    ERIC Educational Resources Information Center

    Croft, Diane L., Ed.

    Detailed product information on peripherals for the blind computer user is provided and applications, availability, reliability, price, and selection considerations are described. Chapters address the following topics and product categories: (1) scanners (optical character readers, Kurzweil Reading Machine); (2) a buyer's guide to modems; (3)…

  20. Guaranteed Access to Campus Network Resources: Policies and Issues.

    ERIC Educational Resources Information Center

    Hassler, Ardoth A.

    1998-01-01

    Reports on a options and issues discussion at a December 1997 Orlando (Florida) meeting of CAUSE97 on providing access to campus technology resources. Options discussed included departmentally and/or university-owned modems, third-party provider contracts, and using wireless access. Issues included providing authentication, assuring network…

  1. [Psychopathology and clinical features of oneiroid-catatonic conditions during endogenous diseases].

    PubMed

    Alekseeva, A G

    2011-01-01

    Psychopathology and clinical features of oneiroid-catatonic conditions during endogenous diseases remain a topical problem in modem psychiatry. The author describes psychopathologcal features of oneiroid depending on the form of the affect and presents new data on its relation to peculiarities of the development of attacks.

  2. Top pruning

    Treesearch

    Thomas D. Landis

    2005-01-01

    Controlling plant height is always a challenge because shoot growth is stimulated in modem nursery environments (Figure 1). To further aggravate the problem, economics forces nurseries to grow their stock at high densities and so plants want to outgrow their neighbors. Inducing mild stresses helps to slow height growth but this has only limited application. Chemical...

  3. Society of Toxicologic Pathologists (STP) Annual Symposium General Session II: Modem Pathology Methods for Neural Investigations

    EPA Science Inventory

    This half-day session at the 20I0 Joint Symposium of the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP) explored many deceptively simple questions related to toxicologic neuropathology. What is the best met...

  4. Two-Way Time Transfer to Airborne Platforms Using Commercial Satellite Modems

    DTIC Science & Technology

    2002-12-01

    on Relativistic Time Transfer . 34th Annual Precise Time and Time Interval (PTTI) Meeting 366 QUESTIONS AND ANSWERS DAVE HOWE (National...Symposium on Frequency Control, 31 May-2 June 1989, Denver, Colorado, USA (IEEE Publication 89CH2690-6), pp. 174-178. [5] R. A. Nelson, 2002, Handbook

  5. How Do Local School Districts Formulate Educational Technology Policy?

    ERIC Educational Resources Information Center

    Hunt, Jeffrey L.; Lockard, James

    This study reports on the formulation of educational technology policy in three Illinois K-12 school districts (n=36). Major findings included: (1) educational policy formulation in the districts focused on collecting the objects of technology, such as computers, modems, networks, rather than viewing educational technology as a systematic process…

  6. Aircraft L-Band Balloon - Simulated Satellite Experiments Volume I: Experiment Description and Voice and Data Modem Test Results

    DOT National Transportation Integrated Search

    1975-10-01

    This report details the result of an experiment performed by the Transportation Systems Center of the Department of Transportation to evaluate candidate voice and data modulation systems for use in an L-Band Air Traffic Control System. The experiment...

  7. The IBM PC as an Online Search Machine--Part 2: Physiology for Searchers.

    ERIC Educational Resources Information Center

    Kolner, Stuart J.

    1985-01-01

    Enumerates "hardware problems" associated with use of the IBM personal computer as an online search machine: purchase of machinery, unpacking of parts, and assembly into a properly functioning computer. Components that allow transformations of computer into a search machine (combination boards, printer, modem) and diagnostics software…

  8. Gyro and Accelerometer Based Navigation System for a Mobile Autonomous Robot.

    DTIC Science & Technology

    1985-12-02

    special thanks goes to our thesis advisor Dr. Matthew Kabrisky for having the confidence to turn us loose on this project. Additionally, we would...Wordmaster Word Processor 1 Wordstar Word Processor 1 Virtual Devices Robo A 6802 Cross Assembler 1 Modem 720 Communication Program 1 CP/M Operating

  9. Wireless sensor network for monitoring soil moisture and weather conditions

    USDA-ARS?s Scientific Manuscript database

    A wireless sensor network (WSN) was developed and deployed in three fields to monitor soil water status and collect weather data for irrigation scheduling. The WSN consists of soil-water sensors, weather sensors, wireless data loggers, and a wireless modem. Soil-water sensors were installed at three...

  10. Network Computing for Distributed Underwater Acoustic Sensors

    DTIC Science & Technology

    2014-03-31

    underwater sensor network with mobility. In preparation. [3] EvoLogics (2013), Underwater Acoustic Modems, (Product Information Guide... Wireless Communications, 9(9), 2934–2944. [21] Pompili, D. and Akyildiz, I. (2010), A multimedia cross-layer protocol for underwater acoustic sensor networks ... Network Computing for Distributed Underwater Acoustic Sensors M. Barbeau E. Kranakis

  11. Networking the Light Fantastic--CD-ROMs on LANs.

    ERIC Educational Resources Information Center

    Kittle, Paul W.

    1992-01-01

    Describes the development of a local area network (LAN) at Loma Linda University that allows remote access for both IBM and Macintosh microcomputers to CD-ROMs. Topics discussed include types of networks; fiber optic technology; networking CD-ROM drives; remote access; modems; CD-ROM databases; memory management; interface software; and future…

  12. The Reality, Direction, and Future of Computerized Publications.

    ERIC Educational Resources Information Center

    Levenstein, Nicholas

    1994-01-01

    Considers potential of personal computers, comparing development of computer today to that of cars in the 1920s. Examines recent changes in communications, university publications, and cultural habits. Explores technological issues, looking at modems and fiber optic cables, better screens, and CD-ROM and optical magnetic drives. (NB)

  13. The Rocket Investigation of Current Closure in the Ionosphere (RICCI) mission: A novel application of CubeSats from a sounding rocket platform

    NASA Astrophysics Data System (ADS)

    Cohen, I. J.; Anderson, B. J.; Lessard, M.; Bonnell, J. W.; Bounds, S. R.; Lysak, R. L.; Erlandson, R. E.

    2017-12-01

    The transfer of energy and momentum between the terrestrial magnetosphere and ionosphere is substantially mediated by large-scale field-aligned currents (FACs), driven by magnetopause dynamics and magnetospheric pressures and closing through the ionosphere where the dissipation and drag are governed. While significant insight into ionospheric electrodynamics and the nature of magnetosphere-ionosphere (M-I) coupling have been gained by rocket and satellite measurements, in situ measurement of these ionospheric closure currents remains challenging. To date the best estimates of ionospheric current densities are inferred from ground-based radar observations combining electric fields calculated from drifts with conductivities derived from densities. RICCI aims to observe the structure of the ionospheric currents in situ to determine how the altitude structure of these currents is related to precipitation and density cavities, electromagnetic dynamics, and governs energy dissipation in the ionosphere. In situ measurement of the current density using multi-point measurements of the magnetic field requires precise attitude knowledge for which the only demonstrated technique is the use of star camera systems. The low vehicle rotation rates required for miniature commercial off-the-shelf (COTS) star cameras prohibit the use of available rocket sub-payload technologies at Wallops Flight Facility (WFF) which use high rates of spin to stabilize attitude. However, CubeSat attitude systems are already designed to achieve low vehicle rotation rates, so RICCI will use a set of three CubeSat sub-payloads deployed from a main low altitude payload with apogee of 160 km to provide precise current density measurement through the ionospheric closure altitude regime, together with a second rocket with apogee near 320 km to measure the incident input energy flux and convection electric field. The two rocket payloads and CubeSate sub-payloads are all instrumented with star cameras and science-grade magnetometers. We discuss the mission design, payload complement, and science closure of this sub-orbital mission to obtain the first direct measurement of ionospheric currents associated with an auroral arc.

  14. Data Acquisition (DAQ) system dedicated for remote sensing applications on Unmanned Aerial Vehicles (UAV)

    NASA Astrophysics Data System (ADS)

    Keleshis, C.; Ioannou, S.; Vrekoussis, M.; Levin, Z.; Lange, M. A.

    2014-08-01

    Continuous advances in unmanned aerial vehicles (UAV) and the increased complexity of their applications raise the demand for improved data acquisition systems (DAQ). These improvements may comprise low power consumption, low volume and weight, robustness, modularity and capability to interface with various sensors and peripherals while maintaining the high sampling rates and processing speeds. Such a system has been designed and developed and is currently integrated on the Autonomous Flying Platforms for Atmospheric and Earth Surface Observations (APAESO/NEA-YΠOΔOMH/NEKΠ/0308/09) however, it can be easily adapted to any UAV or any other mobile vehicle. The system consists of a single-board computer with a dual-core processor, rugged surface-mount memory and storage device, analog and digital input-output ports and many other peripherals that enhance its connectivity with various sensors, imagers and on-board devices. The system is powered by a high efficiency power supply board. Additional boards such as frame-grabbers, differential global positioning system (DGPS) satellite receivers, general packet radio service (3G-4G-GPRS) modems for communication redundancy have been interfaced to the core system and are used whenever there is a mission need. The onboard DAQ system can be preprogrammed for automatic data acquisition or it can be remotely operated during the flight from the ground control station (GCS) using a graphical user interface (GUI) which has been developed and will also be presented in this paper. The unique design of the GUI and the DAQ system enables the synchronized acquisition of a variety of scientific and UAV flight data in a single core location. The new DAQ system and the GUI have been successfully utilized in several scientific UAV missions. In conclusion, the novel DAQ system provides the UAV and the remote-sensing community with a new tool capable of reliably acquiring, processing, storing and transmitting data from any sensor integrated on an UAV.

  15. Advanced Telecommunications Technologies in Rural Communities: Factors Affecting Use.

    ERIC Educational Resources Information Center

    Leistritz, F. Larry; Allen, John C.; Johnson, Bruce B.; Olsen, Duane; Sell, Randy

    1997-01-01

    A survey of 2,000 rural residents in 6 states (36% response) found that 56% used answering machines, 48% fax machines, 46% personal computers, 27% cell phones, and 25% modems. Higher use was associated with higher income and education. Distance from the nearest metropolitan statistical area increased use. A large majority believed…

  16. Innovations in e-Business: Can Government Contracting be Adapted to Use Crowdsourcing and Open Innovation?

    DTIC Science & Technology

    2010-09-01

    cards and software in almost any computer can communicate with each other seamlessly. The cable modem protocol is another example of competing...streaming: it means that special client software applications known as podcatchers (such as Apple Inc.’s iTunes or Nullsoft’s Winamp) can automatically

  17. Graphical Internet Access on a Budget: Making a Pseudo-SLIP Connection.

    ERIC Educational Resources Information Center

    McCulley, P. Michael

    1995-01-01

    Examines The Internet Adapter (TIA), an Internet protocol that allows computers to be directly on the Internet and access graphics over standard telephone lines using high-speed modems. Compares TIA's system requirements, performance, and costs to other Internet connections. Sidebars describe connections other than TIA and how to find information…

  18. 41 CFR 101-42.202 - Identification of hazardous materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...'s Federal Supply Service (4FQ) maintains an automated data base, accessible via modem and computer... on the terminal screen, the system allows for the addition of the MSDS to the user's local data base... personnel who handle, store, ship, use or dispose of hazardous materials. Each record in the data base is...

  19. 41 CFR 101-42.202 - Identification of hazardous materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...'s Federal Supply Service (4FQ) maintains an automated data base, accessible via modem and computer... on the terminal screen, the system allows for the addition of the MSDS to the user's local data base... personnel who handle, store, ship, use or dispose of hazardous materials. Each record in the data base is...

  20. 41 CFR 101-42.202 - Identification of hazardous materials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...'s Federal Supply Service (4FQ) maintains an automated data base, accessible via modem and computer... on the terminal screen, the system allows for the addition of the MSDS to the user's local data base... personnel who handle, store, ship, use or dispose of hazardous materials. Each record in the data base is...

  1. 41 CFR 101-42.202 - Identification of hazardous materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...'s Federal Supply Service (4FQ) maintains an automated data base, accessible via modem and computer... on the terminal screen, the system allows for the addition of the MSDS to the user's local data base... personnel who handle, store, ship, use or dispose of hazardous materials. Each record in the data base is...

  2. 41 CFR 101-42.202 - Identification of hazardous materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...'s Federal Supply Service (4FQ) maintains an automated data base, accessible via modem and computer... on the terminal screen, the system allows for the addition of the MSDS to the user's local data base... personnel who handle, store, ship, use or dispose of hazardous materials. Each record in the data base is...

  3. 76 FR 60765 - Mail or Telephone Order Merchandise Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... access, not telephone dial-up. \\19\\ U.S. Census Bureau, E-Stats, 2007 E-Commerce Multi-Sector Report, May... Shopping and Mail-Order Houses--Total and E-Commerce Sales by Merchandise Line: 2006-2007. Second, consumer... buyers access the Internet (e.g., dial-up telephone modem, cable, or wireless); (2) allow sellers to...

  4. A Mobile Online/CD-ROM Workstation for Demos and Instruction.

    ERIC Educational Resources Information Center

    Wright, Carol; Friend, Linda

    1991-01-01

    Describes a mobile workstation that was developed at Penn State University to provide library instruction and demonstrations of online and CD-ROM searching. Use of the workstation for classroom instruction and staff training is discussed; and designing the workstation to include a computer, overhead projector, modem, CD-ROM drive, and printer is…

  5. Information Dissemination for Pollution Prevention

    DTIC Science & Technology

    2000-04-01

    which may be traced in modem times to the building of the early fully electronic computers after World War II, e.g., the ENIAC in 1946. It is the...PREVENTION May 5-7, 1999 Dr. Alfred Brenner Institute for Defense Analyses Alexandria, Virginia 90414ABS1- 1 THE INFORMATION AGE MILESTONES "• ENIAC 1946

  6. [The training of administration personnel for private medical organizations].

    PubMed

    2012-01-01

    The training of administration personnel for medical institutions is an integral part of the restructuring of health care. The authors proposed a system approach during the development of business-competences needed for modem medicine to provide the corresponding level of activity in the conditions of market economy and modernization of health care system.

  7. WIRELESS Computing in Schools: Reach Out and Touch the World.

    ERIC Educational Resources Information Center

    Null, Linda; Teschner, Randy

    Many elementary and secondary schools tie with local colleges and universities and use modems to access the computing power available at these higher education facilities. To help alleviate the financial burden of long-distance phone charges, work had begun to use the airways instead of phone lines for computer communication. An interest in…

  8. Education on the Electronic Frontier: Teleapprentices in Globally Distributed Educational Contexts. Interactive Technology Laboratory Report #14.

    ERIC Educational Resources Information Center

    Levin, James A.; And Others

    1987-01-01

    The instructional media created by microcomputers interconnected by modems to form long-distance networks present some powerful new opportunities for education. While other uses of computers in education have been built on conventional instructional models of classroom interaction, instructional electronic networks facilitate a wider use of…

  9. Proceedings Second International Conference on Composite Science and Technology 9 - 11 June 1998 Durban South Africa

    DTIC Science & Technology

    1998-06-01

    Adali, and V.E. Verijenko ............................................... 17 Modem conceptions of plate theory V. V. Vasiliev ... higher order theory D . H uang and B . Sun...793, 1997. 29 30 MODERN CONCEPTIONS OF PLATE THEORY V. V. VASILIEV Department of Mechanics and Optimization of Processes and Structures Moscow State

  10. A Survey of Recent Advances in Optical and Multimedia Information Technologies.

    ERIC Educational Resources Information Center

    Jessop, Deborah

    1997-01-01

    Examines developments in multimedia technologies and in the World Wide Web. Discusses CD-recordable, CD-rewritable, cable modems, personal digital assistants, digital video discs, interactivity and virtual worlds, advertising on the Web, and Intranets and CD-ROM networks. Eight tables and figures show costs, download time, estimated sales, storage…

  11. Scholarly Publishing in the Electronic Age: A Graduate Student's Perspective.

    ERIC Educational Resources Information Center

    Thompsen, Philip A.

    The issue of whether the nature of scholarship is being changed by electronic publishing was made clear to a graduate student when his telecommunication link to the world (his modem) failed. While the newer forms of academic communication offer impressive advantages over traditional publishing, scholars still feel compelled to retain somehow the…

  12. Targeted enrichment strategies for next-generation plant biology

    Treesearch

    Richard Cronn; Brian J. Knaus; Aaron Liston; Peter J. Maughan; Matthew Parks; John V. Syring; Joshua Udall

    2012-01-01

    The dramatic advances offered by modem DNA sequencers continue to redefine the limits of what can be accomplished in comparative plant biology. Even with recent achievements, however, plant genomes present obstacles that can make it difficult to execute large-scale population and phylogenetic studies on next-generation sequencing platforms. Factors like large genome...

  13. How to Get from Cupertino to Boca Raton.

    ERIC Educational Resources Information Center

    Troxel, Duane K.; Chiavacci, Jim

    1985-01-01

    Describes seven methods to transfer data from Apple computer disks to IBM computer disks and vice versa: print out data and retype; use a commercial software package, optical-character reader, homemade cable, or modem to pass or transfer data directly; pay commercial data-transfer service; or store files on mainframe and download. (MBR)

  14. Sharing Writing on an Electronic Network.

    ERIC Educational Resources Information Center

    Schwartz, Jeffrey

    A writing exchange project at Bread Loaf School of English at Middlebury College in Vermont, funded by Apple Education Foundation and McDonnell Douglas, examined what happened when high school students use word processors and a modem to write to distant audiences. In the first exchange, students interviewed each other in pairs and wrote short…

  15. Future Integrated Architecture (FIA): A Proposed Space Internetworking Architecture for Future Operations

    DTIC Science & Technology

    2008-09-01

    WiMax “as a ‘last mile’ broadband wireless access (BWA) alternative to cable modem service, telephone company Digital Subscriber Line (DSL) or T1/E1...MUOS at 56k , shows results similar to another simulation with different circuit configurations. Analysis presented in this thesis shows adequate

  16. Distributed Name Servers: Naming and Caching in Large Distributed Computing Environments

    DTIC Science & Technology

    1985-12-01

    transmission rate of the communication medium1, transmission over a 56K bps line costs approx- imately 54r, and similarly, communication over a 9.6K...memories for modem computer systems attempt to maximize the hit ratio for a fixed-size cache by utilizing intelligent cache replacement algorithms

  17. Using AUVs and Sources of Opportunity to Evaluate Acoustic Propagation

    DTIC Science & Technology

    1999-09-30

    pattern simulated that of a typical minefield survey. The AUV followed a lawn mower pattern with a constant 3-knot speed inside a 500-m square grid box...same lawn mower pattern as used in the previous experiment, except it only surfaced at the east turns. Thirdly, the MFSK modem signal was only

  18. Modern Amphibious Operations: Why the United States Must Maintain a Joint Amphibious Forcible Entry Capability

    DTIC Science & Technology

    2012-03-23

    be reminded that the aforementioned movies depicted events that happened nearly 70 years ago.48 These films neither represent modem amphibious...contemporary sources. Few are more contemporary than those in this genre . Nothing can substitute a simple Google web search to get ideas about where

  19. A Technology Enabled Journey

    ERIC Educational Resources Information Center

    Devine, Pamela Albert

    2012-01-01

    This article features Point Road School, a pre-K-4 school in New Jersey that enhances student learning by integrating new and emerging technologies into the curriculum. Point Road School's technology story began in 1996 with a grant for a classroom modem so students could email their university literacy buddies. The New Jersey school has moved…

  20. The Minimalist Syntax of Control in Greek

    ERIC Educational Resources Information Center

    Kapetangianni, Konstantia

    2010-01-01

    This dissertation investigates Control phenomena in three distinct domains of the grammar of Modem Greek (subjunctive complements, "V-ondas" adjuncts and ke-complements) and proposes a unifying syntactic account of Control by appealing to the tense properties of these domains. I argue that Control in Greek is best analyzed as an instance of…

  1. The Kobe Earthquake: Telecommunications Survives at Kobe University.

    ERIC Educational Resources Information Center

    Garland, Virginia E.; Morimoto, Mayumi

    1996-01-01

    Describes the use of telecommunications in the aftermath of the Kobe earthquake. Topics include the use of e-mail for communication as well as for disaster relief efforts, use of the Internet and World Wide Web home pages, and the usefulness of portable computers with built-in modems for fax capabilities. (LRW)

  2. General Aviation Light Aircraft Propulsion: From the 1940's to the Next Century

    NASA Technical Reports Server (NTRS)

    Burkardt, Leo A.

    1998-01-01

    Current general aviation light aircraft are powered by engines that were originally designed in the 1940's. This paper gives a brief history of light aircraft engine development, explaining why the air-cooled, horizontally opposed piston engine became the dominant engine for this class of aircraft. Current engines are fairly efficient, and their designs have been updated through the years, but their basic design and operational characteristics are archaic in comparison to modem engine designs, such as those used in the automotive industry. There have been some innovative engine developments, but in general they have not been commercially successful. This paper gives some insight into the reasons for this lack of success. There is now renewed interest in developing modem propulsion systems for light aircraft, in the fore-front of which is NASA's General Aviation Propulsion (GAP) program. This paper gives an overview of the engines being developed in the GAP program, what they will mean to the general aviation community, and why NASA and its industry partners believe that these new engine developments will bring about a new era in general aviation light aircraft.

  3. 802.16e System Profile for NASA Extra-Vehicular Activities

    NASA Technical Reports Server (NTRS)

    Foore, Lawrence R.; Chelmins, David T.; Nguyen, Hung D.; Downey, Joseph A.; Finn, Gregory G.; Cagley, Richard E.; Bakula, Casey J.

    2009-01-01

    This report identifies an 802.16e system profile that is applicable to a lunar surface wireless network, and specifically for meeting extra-vehicular activity (EVA) data flow requirements. EVA suit communication needs are addressed. Design-driving operational scenarios are considered. These scenarios are then used to identify a configuration of the 802.16e system (system profile) that meets EVA requirements, but also aim to make the radio realizable within EVA constraints. Limitations of this system configuration are highlighted. An overview and development status is presented by Toyon Research Corporation concerning the development of an 802.16e compatible modem under NASA s Small Business Innovative Research (SBIR) Program. This modem is based on the recommended system profile developed as part of this report. Last, a path forward is outlined that presents an evolvable solution for the EVA radio system and lunar surface radio networks. This solution is based on a custom link layer, and 802.16e compliant physical layer compliant to the identified system profile, and a later progression to a fully interoperable 802.16e system.

  4. IP-Based Video Modem Extender Requirements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pierson, L G; Boorman, T M; Howe, R E

    2003-12-16

    Visualization is one of the keys to understanding large complex data sets such as those generated by the large computing resources purchased and developed by the Advanced Simulation and Computing program (aka ASCI). In order to be convenient to researchers, visualization data must be distributed to offices and large complex visualization theaters. Currently, local distribution of the visual data is accomplished by distance limited modems and RGB switches that simply do not scale to hundreds of users across the local, metropolitan, and WAN distances without incurring large costs in fiber plant installation and maintenance. Wide Area application over the DOEmore » Complex is infeasible using these limited distance RGB extenders. On the other hand, Internet Protocols (IP) over Ethernet is a scalable well-proven technology that can distribute large volumes of data over these distances. Visual data has been distributed at lower resolutions over IP in industrial applications. This document describes requirements of the ASCI program in visual signal distribution for the purpose of identifying industrial partners willing to develop products to meet ASCI's needs.« less

  5. Development of a light-weight, wind-turbine-rotor-based data acquisition system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berg, D.E.; Rumsey, M.; Robertson, P.

    1997-12-01

    Wind-energy researchers at Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) are developing a new, light-weight, modular system capable of acquiring long-term, continuous time-series data from current-generation small or large, dynamic wind-turbine rotors. Meetings with wind-turbine research personnel at NREL and SNL resulted in a list of the major requirements that the system must meet. Initial attempts to locate a commercial system that could meet all of these requirements were not successful, but some commercially available data acquisition and radio/modem subsystems that met many of the requirements were identified. A time synchronization subsystem and a programmable logicmore » device subsystem to integrate the functions of the data acquisition, the radio/modem, and the time synchronization subsystems and to communicate with the user have been developed at SNL. This paper presents the data system requirements, describes the four major subsystems comprising the system, summarizes the current status of the system, and presents the current plans for near-term development of hardware and software.« less

  6. A Model-based Framework for Risk Assessment in Human-Computer Controlled Systems

    NASA Technical Reports Server (NTRS)

    Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems. This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions. Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  7. [The place and the role of topographic and clinical anatomy in the modern system of higher medical education].

    PubMed

    Bol'shakov, O P

    2008-01-01

    Modern data on studying and teaching topographic and clinical anatomy in Russia and in the foreign countries at the boundary between the XX and the XXI centuries are analyzed. Definitions of some concepts are given; methodological and organizational bases of studying topographic and clinical anatomy are examined in historical aspect. Various approaches to the teaching and studying of these disciplines in different countries, are demonstrated. Special attention is given to the use of new technologies in teaching; the experience of virtual mode of studying of applied anatomy and surgical techniques is critically evaluated. Article presents author's own opinion and analyzes the conceptions of the foreign authors on the necessity of rational combination of computer and other modem technologies with traditional methods of work using biological materials and experiments on laboratory animals. The longstanding experience of the departments of operative surgery and clinical anatomy is summarized and the benefits of the national system of teaching of applied (topographic and clinical) anatomy are shown. Modem tendencies and priorities in the development of topographic and clinical anatomy are demonstrated.

  8. Development of Open source-based automatic shooting and processing UAV imagery for Orthoimage Using Smart Camera UAV

    NASA Astrophysics Data System (ADS)

    Park, J. W.; Jeong, H. H.; Kim, J. S.; Choi, C. U.

    2016-06-01

    Recently, aerial photography with unmanned aerial vehicle (UAV) system uses UAV and remote controls through connections of ground control system using bandwidth of about 430 MHz radio Frequency (RF) modem. However, as mentioned earlier, existing method of using RF modem has limitations in long distance communication. The Smart Camera equipments's LTE (long-term evolution), Bluetooth, and Wi-Fi to implement UAV that uses developed UAV communication module system carried out the close aerial photogrammetry with the automatic shooting. Automatic shooting system is an image capturing device for the drones in the area's that needs image capturing and software for loading a smart camera and managing it. This system is composed of automatic shooting using the sensor of smart camera and shooting catalog management which manages filmed images and information. Processing UAV imagery module used Open Drone Map. This study examined the feasibility of using the Smart Camera as the payload for a photogrammetric UAV system. The open soure tools used for generating Android, OpenCV (Open Computer Vision), RTKLIB, Open Drone Map.

  9. Safety Metrics for Human-Computer Controlled Systems

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy G; Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems.This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  10. The Pilot Land Data System (PLDS) at the Ames Research Center manages aircraft data in collaboration with an ecosystem research project

    NASA Technical Reports Server (NTRS)

    Angelici, Gary; Popovici, Lidia; Skiles, Jay

    1991-01-01

    The Pilot Land Data System (PLDS) is a data and information system serving NASA-supported investigators in the land science community. The three nodes of the PLDS, one each at the Ames Research Center (ARC), the Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL), cooperate in providing consistent information describing the various data holding in the hardware and software (accessible via network and modem) that provide information about and access to PLDS-held data, which is available for distribution. A major new activity of the PLDS node at the Ames Research Center involves the interaction of the PLDS with an active NASA ecosystem science project, the Oregon Transect Ecosystems Research involves the management of, access to, and distribution of the large volume of widely-varying aircraft data collected by OTTER. The OTTER project, is managed by researchers at the Ames Research Center and Oregon State University. Its principal objective is to estimate major fluxes of carbon, nitrogen, and water of forest ecosystems using an ecosystem process model driven by remote sensing data. Ten researchers at NASA centers and universities are analyzing data for six sites along a temperature-moisture gradient across the western half of central Oregon (called the Oregon Transect). Sensors mounted on six different aircraft have acquired data over the Oregon Transect in support of the OTTER project.

  11. An Assessment of Technical and Production Risks of Candidate Low-Cost Attitude/Heading Reference Systems(AHRS)

    NASA Technical Reports Server (NTRS)

    Yuchnovicz, Daniel; Burgess, Malcolm; Hammers, William

    1999-01-01

    This report provides an assessment of technical and production risks of candidate low-cost attitude/heading reference systems (AHRS) for use in the Advanced General Aviation Transport Experiments (AGATE) airplanes. A low-cost AHRS is a key component of modem "glass cockpit" flight displays for General Aviation (GA) aircraft. The technical capabilities of several candidate low-cost AHRS were examined and described along with the technical issues involved with using all solid-state components for attitude measurement. An economic model was developed which describes the expected profit, rate of return, and volume requirements for the manufacture of low-cost AHRS for GA aircraft in the 2000 to 2020 time frame. The model is the result of interviews with GA airframe manufacturers, avionics manufacturers and historical analysis of avionics of similar complexity. The model shows that a manufacturer will break even after three years of AHRS production, realizing an 18 percent rate of return (23 percent profit) on an investment of $3.5M over the 20 year period. A start-up production estimate showed costs of $6-12M for a new company to build and certify an AHRS from scratch, considered to be a high-risk proposition, versus $0.25-0.75M for an experienced avionics manufacturer to manufacture a design under license, a low-risk proposition.

  12. Digital tracking loops for a programmable digital modem

    NASA Technical Reports Server (NTRS)

    Poklemba, John J.

    1992-01-01

    In this paper, an analysis and hardware emulation of the tracking loops for a very flexible programmable digital modem (PDM) will be presented. The modem is capable of being programmed for 2, 4, 8, 16-PSK, 16-QAM, MSK, and Offset-QPSK modulation schemes over a range of data rates from 2.34 to 300 Mbps with programmable spectral occupancy from 1.2 to 1.8 times the symbol rate; these operational parameters are executable in burst or continuous mode. All of the critical processing in both the modulator and demodulator is done at baseband with very high-speed digital hardware and memory. Quadrature analog front-ends are used for translation between baseband and the IF center frequency. The modulator is based on a table lookup approach, where precomputed samples are stored in memory and clocked out according to the incoming data pattern. The sample values are predistorted to counteract the effects of the other filtering functions in the link as well as any transmission impairments. The demodulator architecture was adapted from a joint estimator-detector (JED) mathematical analysis. Its structure is applicable to most signalling formats that can be represented in a two-dimensional space. The JED realization uses interdependent, mutually aiding tracking loops with post-detection data feedback. To expedite and provide for more reliable synchronization, initial estimates for these loops are computed in a parallel acquisition processor. The cornerstone of the demodulator realization is the pre-averager received data filter which allows operation over a broad range of data rates without any hardware changes and greatly simplifies the implementation complexity. The emulation results confirmed tracking loop operation over the entire range of operational parameters listed above, as well as the capability of achieving and maintaining synchronization at BER's in excess of 10(exp -1). The emulation results also showed very close agreement with the tracking loop analysis, and validated the resolution apportionment of the various hardware elements in the tracking loops.

  13. Plate Boundary Observatory GPS Network Status in California

    NASA Astrophysics Data System (ADS)

    Walls, C. P.; Austin, K. E.; Dittman, T.; Mann, D.; Basset, A.; Turner, R.; Lawrence, S.; Woolace, A. C.; Kasmer, D.; Hodgkinson, K. M.; Feaux, K.; Mattioli, G. S.

    2015-12-01

    The EarthScope PBO GPS network, funded by the NSF and operated by UNAVCO, is comprised of 599 permanent GPS stations spanning three principal tectonic regimes and is administered by separate management regions (Subduction - Pacific Northwest [91 sites], Extension - East [41 sites], Transform - Southwest [467 sites]). Since the close of construction in September 2008 various enhancements have been implemented through additional funding by the NSF, NOAA, and NASA and in collaboration with stakeholders such as Caltrans, Scripps, and the USGS. Initially, the majority of stations used first generation IP based cellular modems and radios capable of ~10KB/s data rates. The bandwidth limitation was a challenge for regional high-rate data downloads for GPS-seismology and airborne LiDAR surveys, and real-time data flow. Today, only 13 of the original cell modems remain with 297 upgraded cell modems providing 3G/4G/LTE data communications with transfer rates ranging from 80-400 KB/s. Ongoing radio network expansion and upgrades continue to harden communications. 32 VSAT and one manual download site remain. In CA, the network capabilities for 1Hz and 5Hz downloads or real-time streaming are ~95%, ~80% and ~65%, respectively. During the past year, uptime ranged from 94-99% with data return for 15 s data exceeding 99%. Real-time (1 Hz) data from 204 sites are distributed in BINEX and RTCM 2.3/3.1 formats with an average latency of 0.5 s and completion of 86%. A variety of geophysical sensors are co-located with the GPS stations and include: 21 MEMS accelerometers, 31 strong motion and broadband seismometers, 9 borehole strainmeters and 1 long baseline strainmeter. Vaisala meteorological instruments are located at 60 sites of which 38 stream GPS/Met data. In an effort to modernize the network, Trimble NetRS receivers are gradually being replaced with GNSS-capable/enabled receivers and antennas. Today, 11 stations are GLONASS enabled and 84 are GNSS capable.

  14. Advanced technology satellite demodulator development

    NASA Technical Reports Server (NTRS)

    Ames, Stephen A.

    1989-01-01

    Ford Aerospace has developed a proof-of-concept satellite 8 phase shift keying (PSK) modulation and coding system operating in the Time Division Multiple Access (TDMA) mode at a data range of 200 Mbps using rate 5/6 forward error correction coding. The 80 Msps 8 PSK modem was developed in a mostly digital form and is amenable to an ASIC realization in the next phase of development. The codec was developed as a paper design only. The power efficiency goal was to be within 2 dB of theoretical at a bit error rate (BER) of 5x10(exp 7) while the measured implementation loss was 4.5 dB. The bandwidth efficiency goal was 2 bits/sec/Hz while the realized bandwidth efficiency was 1.8 bits/sec/Hz. The burst format used a preamble of only 40 8 PSK symbol times including 32 symbols of all zeros and an eight symbol unique word. The modem and associated special test equipment (STE) were fabricated mostly on a specially designed stitch-weld board although a few of the highest rate circuits were built on printed circuit cards. All the digital circuits were ECL to support the clock rates of from 80 MHz to 360 MHz. The transmitter and receiver matched filters were square-root Nyquist bandpass filters realized at the 3.37 GHz i.f. The modem operated as a coherent system although no analog phase locked (PLL) loop was employed. Within the budgetary constraints of the program, the approach to the demodulator has been proven and is eligible to proceed to the next phase of development of a satellite demodulator engineering model. This would entail the development of an ASIC version of the digital portion of the demodulator, and MMIC version of the quadrature detector, and SAW Nyquist filters to realize the bandwidth efficiency.

  15. [The domestic aviation and space medicine reflected in phaleristics].

    PubMed

    Zhdan'ko, I M; Ryzhenko, S P; Khomenko, M N; Golosov, S Iu; Sobolenko, D A

    2013-04-01

    The article is devoted to the connection between the badges of medical institutions that are material evidence of formation and development of domestic aviation and space medicine and the history of Armed forces. The authors describe development of aviation and space medicine phaleristics, which is an important factor for patriotic education of modem scientific and military medical personnel.

  16. CVN’s, is Eleven Too Many or Too Few?

    DTIC Science & Technology

    2011-03-10

    allows for transit and work ups for deployment. The complete cycle has one ship on post, one corning off post and one preparing to take post in each of...developed the Silk Missile, an. anti -ship missile that can sink a smaller vessel with one burst. Many of the defenses used in the modem carrier

  17. Taking It to the Streets: Mobile CD-ROM Workshops on Campus.

    ERIC Educational Resources Information Center

    Parker-Gibson, Necia

    1994-01-01

    Librarians at the University of Arkansas (Fayetteville) offer CD-ROM database and online catalog training using a portable unit composed of a laptop computer, modem, LCD panel, and overhead projector. This unit allows librarians to make presentations to large groups and to demonstrate to faculty and students the relevancy of library technology.…

  18. Translocalisation over the Net: Digitalisation, Information Technology and Local Cultures in Melanesia

    ERIC Educational Resources Information Center

    Kupiainen, Jari

    2006-01-01

    In the Western Pacific, the People First Network project has since 2001 been building a growing network of rural email stations across the conflict-ridden Solomon Islands. These stations are based on robust technology and consist of solar panels, short-wave radios and compatible modems, laptop computers and printers to provide email communication…

  19. Improving the U.S. Navy’s Execution of Technical Authority through a Common Risk Management and Technical Assessment Process

    DTIC Science & Technology

    2008-09-01

    ITP . Assessment Indicators: • Has the risk management team (RMT) provided a risk management plan (RMP)? − Does the RMP provide an organized...processes. Diskettes, which contain the necessary programs for accessing BMP◊NET from IBM -compatible or Macintosh computers with a modem, and answers to

  20. Jamming the Phone Lines: Pencils, Notebooks, and Modems (Computers in the Classroom).

    ERIC Educational Resources Information Center

    Holvig, Kenneth C.

    1989-01-01

    Describes how BreadNet (a national computer network of English teachers) has come to dominate the routine of a high school class. Notes that BreadNet gives students new motivation to write, inquire, and learn. Describes classroom electronic writing exchanges and an electronic writers' workshop which posted essays on BreadNet. (RS)

  1. 76 FR 28251 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... establish pricing for customers who are not co-located in the Exchange's data center, but require shared cabinet space and power for optional routers, switches, or modems to support their direct circuit...'' space and a maximum power of 125 Watts per U space. Currently, non co-located customers are assessed...

  2. Exploring the Aesthetics of Rape in the Work of Juan de Moncayo y Gurrea

    ERIC Educational Resources Information Center

    McVay, Ted E., Jr.

    2009-01-01

    Interpreting the occurrence of sexual violation in seventeenth-century Spanish literary works necessitates for modem scholars the difficult task of understanding prevailing contemporary attitudes toward rape. Studies by Higgins and Silver, Casas, and Welles discuss how literary texts with rape scenes as narrative material often use the act or its…

  3. USSR Report, Cybernetics, Computers and Automation Technology

    DTIC Science & Technology

    1985-08-28

    alphanumerical dis- plays SM 7206 and SM 7401, graphics displays SM 7300 and SM 7301, modems SM 8105, SM 8107 and SM 8108, and so on. Today it is...3 are written in assembler and PL-1. They require 56k to 200 k memory for operation. S0RT-7/SM sorting subsystem was developed in conjunction with

  4. Cultivating Innovation to Ignite Organizational Transformation

    DTIC Science & Technology

    2004-03-01

    over a modem . Need to have a section entitled "incoming students" The current site and design sitemap make and incoming student hunt through the...Download Times: Estimated download times (seconds) Object type Number Size (bytes) 14.4 28.8 33.6 56K 128K T1 HTML 1 8600 6.27 3.44 2.87 2.46

  5. Digital Troposcatter Performance Model

    DTIC Science & Technology

    1983-12-01

    Dist Speia DIIBUTON STATEMR AO Approved tot public relemg ** - DistributionUnlimited __________ Communications. Control and Information Systems ...for digital troposcatter communication system design is described. Propagation and modem performance *are modeled. These include Path Loss and RSL...designing digital troposcatter systems . A User’s Manual Report discusses the use of the computer program TROPO. The description of the structure and logical

  6. A Nationwide Communication System for the Hearing Impaired: Strategies Toward Commercial Implementation. Final Report.

    ERIC Educational Resources Information Center

    Allan, Daniel S.; And Others

    The purpose of this report is to assess the viability of developing commercial computer communications networks to provide communications services to the deaf community on a nationwide basis. Access to this network is considered for existing Baudot/Weitbrecht Telecommunications Devices for the Deaf (TDDs) and ASCII terminals with Bell modems. The…

  7. Leveraging the NPS Femto Satellite for Alternative Satellite Communication Networks

    DTIC Science & Technology

    2017-09-01

    the next-generation NPSFS. 14. SUBJECT TERMS space , Femto satellite, NPSFS, network, communication , Arduino, RockBlock, Iridium Modem 15. NUMBER...provides a proof of concept for using Naval Postgraduate School Femto Satellites (NPSFS) as an alternative communication space -based network. The...We need several physical and procedural elements to conduct communication through space and using the electromagnetic spectrum. 1. Power Any

  8. Parcelization and affluence: Implications for nonindustrial private forests

    Treesearch

    Donald. F. Dennis

    1992-01-01

    The quality of life we cherish is in many ways dependent on the health and accessibility of our forests. Forests provide recreational and aesthetic relief from the pressures of modem society, as well as the raw material for a multitude of wood products. Many rural communities rely heavily on economic benefits provided by timber, tounsm, and other forest-related rec-...

  9. Introductory Talk: Whole Frog Project

    Science.gov Websites

    geometric primitives (points, lines, polygons, etc.) that accurately represent the shape of the surface constant value (color). This operation effectively defines the boundary between areas of different color about 10 seconds on a 56K baud modem. The controls can be set to send compressed images of 3 different

  10. Are On-Line Data Bases in Your Library's Future?

    ERIC Educational Resources Information Center

    Deacon, Jim

    1983-01-01

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: Today there are over 900 on-line data banks available for public access. Most microcomputers can use them through the aid of a modem and communication program. Major public information utilities that offer access to these on-line data bases are growing and expanding. The Source, a data base utility…

  11. Islam and Science

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    The following sections are included: * The Holy Quran and Science * Modem Science, A Greco- Islamic Legacy * The Decline of Sciences in Islam * The Limitations of Science * Faith and Science * The Present Picture of Sciences in the Islamic Countries * Renaissance of Sciences in Islam * Steps Needed for Building up Sciences in the Islamic Countries * Science Education * Science Foundations in Islam * Technology in Our Countries * Concluding Remarks * REFERENCES

  12. Using an Electronic Network To Create a Read Context for High School Writing.

    ERIC Educational Resources Information Center

    Schwartz, Jeffrey

    In an effort to broaden the context for classroom writing by providing an audience other than the teacher and classmates, a study used microcomputers, a modem and an electronic mail service to set up communications with classes in other communities. Two classes (27 students) at Sewickley Academy in Pennsylvania communicated for a semester with two…

  13. Mentoring by Modem. Connect for Kids: Guidance for Grown-Ups.

    ERIC Educational Resources Information Center

    Newberger, Julee

    This article describes the use of an eMentoring program by the Orphan Foundation of America, a nonprofit organization dedicated to helping young people move out of foster care and into adult life. The eMentoring program, which allows youth and their mentors to communicate via e-mail, helps foster youth prepare for work life by matching them with…

  14. The Design of an Interactive Computer Based System for the Training of Signal Corps Officers in Communications Network Management

    DTIC Science & Technology

    1985-08-01

    from the mainframe to the terminals is approximately 56k bits per second (21:3). Score: 8. Expandability. The number of terminals available to the 0...the systems controllers may access any files. For modem link up, a callback system is to be implemented to prevent unauthorized off post access (10:2

  15. GNAS Maintenance Control Center (GMCC) Design Qualification Test and Evaluation (DQT&E) Test Procedures

    DTIC Science & Technology

    1992-06-01

    connected to one MPS via BROUTERS and modems ). b. MPS - RMMS interface to the GMCC. The IMCS software running on the MPS will.be used to monitor the...Start Date: TODAYS DATE REGION: SO Sector: 56K 69. GPWS: Press FI0 (PRODUCE REPORT) to generate the report. 70. GPWS: Press F12 (REPORT STATUS) to

  16. The DISAM Journal of International Security Assistance Management. Volume 24, Number 2, Winter 2001-2002

    DTIC Science & Technology

    2002-01-01

    speeds that are sufficient to download and play the audio/video content in near real-time. Most users at home are connected via analog modems , which are...significantly slower (28.8K, 56K ). Audio files can take several minutes to load, and the user may experience pauses and buffering. While not ideal

  17. Effects of Policy and Technological Change on Land Use

    Treesearch

    Ralph J. Alig; Mary Clare Ahearn

    2004-01-01

    Land use in the United States is dynamic, as discussed in Chapter 2, with millions of acres of Land shifting uses each year. Many of these land-use changes are the result of market forces in an economy affected by modem technology and policy choices. Changes in land use are the result of choices inade by individuals, corporations, nongovernmental organizations, and...

  18. Coherent acoustic communication in a tidal estuary with busy shipping traffic.

    PubMed

    van Walree, Paul A; Neasham, Jeffrey A; Schrijver, Marco C

    2007-12-01

    High-rate acoustic communication experiments were conducted in a dynamic estuarine environment. Two current profilers deployed in a shipping lane were interfaced with acoustic modems, which modulated and transmitted the sensor readings every 200 s over a period of four days. QPSK modulation was employed at a raw data rate of 8 kbits on a 12-kHz carrier. Two 16-element hydrophone arrays, one horizontal and one vertical, were deployed near the shore. A multichannel decision-feedback equalizer was used to demodulate the modem signals received on both arrays. Long-term statistical analysis reveals the effects of the tidal cycle, subsea unit location, attenuation by the wake of passing vessels, and high levels of ship-generated noise on the fidelity of the communication links. The use of receiver arrays enables vast improvement in the overall reliability of data delivery compared with a single-receiver system, with performance depending strongly on array orientation. The vertical array offers the best performance overall, although the horizontal array proves more robust against shipping noise. Spatial coherence estimates, variation of array aperture, and inspection of array angular responses point to adaptive beamforming and coherent combining as the chief mechanisms of array gain.

  19. Image sequence analysis workstation for multipoint motion analysis

    NASA Astrophysics Data System (ADS)

    Mostafavi, Hassan

    1990-08-01

    This paper describes an application-specific engineering workstation designed and developed to analyze motion of objects from video sequences. The system combines the software and hardware environment of a modem graphic-oriented workstation with the digital image acquisition, processing and display techniques. In addition to automation and Increase In throughput of data reduction tasks, the objective of the system Is to provide less invasive methods of measurement by offering the ability to track objects that are more complex than reflective markers. Grey level Image processing and spatial/temporal adaptation of the processing parameters is used for location and tracking of more complex features of objects under uncontrolled lighting and background conditions. The applications of such an automated and noninvasive measurement tool include analysis of the trajectory and attitude of rigid bodies such as human limbs, robots, aircraft in flight, etc. The system's key features are: 1) Acquisition and storage of Image sequences by digitizing and storing real-time video; 2) computer-controlled movie loop playback, freeze frame display, and digital Image enhancement; 3) multiple leading edge tracking in addition to object centroids at up to 60 fields per second from both live input video or a stored Image sequence; 4) model-based estimation and tracking of the six degrees of freedom of a rigid body: 5) field-of-view and spatial calibration: 6) Image sequence and measurement data base management; and 7) offline analysis software for trajectory plotting and statistical analysis.

  20. Implementation and Testing of the JANUS Standard with SSC Pacific’s Software-Defined Acoustic Modem

    DTIC Science & Technology

    2017-12-01

    Communications Outpost (FDECO) Innovative Naval Prototype (INP) Program by the Advanced Photonic Technologies Branch (Code 55360), Space and Naval Warfare... Communications and Networks Division iii EXECUTIVE SUMMARY This report presents Space and Naval Warfare (SPAWAR) Systems Center Pacific’s (SSC... Frequency -Hopped Binary Frequency Shift Keying Office of Naval Research Innovative Naval Prototype Forward Deployed Energy and Communications Outpost

  1. Assessing soil quality: practicable standards for sustainable forest productivity in the United States

    Treesearch

    Robert F. Powers; Allan E. Tiarks; James R. Boyle

    1998-01-01

    Productive soils form the foundation for productive forests. But unfortunately, the significance of soil seems lost to modem society. Most of us are too far removed from the natural factors of production to appreciate the multiple roles of soil. Nor is its worth recognized well by many forest managers who too often see soil only in its capacity for logging roads and...

  2. Examination of the Lateral Attenuation of Aircraft Noise

    NASA Technical Reports Server (NTRS)

    Plotkin, Kenneth J.; Hobbs, Christopher M.; Bradley, Kevin A.; Shepherd, Kevin P. (Technical Monitor)

    2000-01-01

    Measurements of the lateral attenuation of noise from aircraft operations at Denver International Airport were made at distances up to 2000 feet and elevation angles up to 27 degrees. Attenuation Calculated from modem ground impedance theory agrees well with average measured attenuation. The large variability between measured and predicted levels observed at small elevation angles is demonstrated to be due to refraction by wind and temperature gradients.

  3. Quality in the Operational Air Force: A Case of Misplaced Emphasis

    DTIC Science & Technology

    1994-05-01

    other quality advocates of the era. These men included Joseph Juran, Armand Feigenbaum, Kaoru Ishikawa , and Genichi Taguchi. Juran contributed disciplined...planning theories, while Feigenbaum felt that producing quality could actually reduce production costs. In addition, Ishikawa and Taguchi lent...statistically based problem solving techniques, but the more modem approaches of Ishikawa , Taguchi and others. The operative concept of TQM is ’continuous

  4. Toward information management in corporations (7)

    NASA Astrophysics Data System (ADS)

    Yasuda, Naoyoshi

    Personal computers and workstations have come into wide use. The high performance modems will be available at cheaper prices so that the bulletin-board system and electronic mail have been used by many people. This paper discusses the network system, and describes the electronic mail covering wider regions and BBS for research and development. It also describes how to handle document images by use of these measures.

  5. Financing Terror: Analysis and Simulation to Affect Terrorist Organizations’ Financial Infrastructures

    DTIC Science & Technology

    2004-09-15

    research on terrorism existed; David Rapoport, professor emeritus of political science at University of California-Los Angeles, lamented on that relative...contains all books published since 1979. 10 research interests-historical, cultural, religious, political , economic, psychological and organizational factors...perspective, tracing the development of non-state political violence in general and how terrorism has become a primary component of modem political

  6. All Aboard the Internet. E to Go: The Internet in Your Pocket

    ERIC Educational Resources Information Center

    Descy, Don E.

    2006-01-01

    Some remember when they accessed the Internet through the telephone on a 300-baud modem. It was slow and it was not easy, but it gave them a view of the world. Now there is the web, idiot-proof email, and practically unlimited wireless connectivity. Having gone from desktop computers to laptops, now a major push is moving connectivity into the…

  7. Time and Frequency Activities at SP in Sweden

    DTIC Science & Technology

    2009-11-01

    in Sweden and is traceable to UTC via BIPM and time transfer using the GPS and TWSTFT techniques. This paper describes the generation and...is interfaced using IP networking. Long-haul measurement time transfer instrumentation at SP consists of: • a TimeTech Satre TWSTFT ground...time transfer equipment. The clock room contains also sensible measurement equipment such as a femtosecond phase comparator, the TWSTFT modem, the

  8. Integration of an Acoustic Modem onto a Wave Glider Unmanned Surface Vehicle

    DTIC Science & Technology

    2012-06-01

    of the wave and ωτ represents the phase of the wave. After some amount of math and taking the limit as ω →∞ , we arrive at a form of the eikonal ...the phase front. (5.5) 22 0A Aτ τ∇ ⋅∇ + ∇ = The transport equation and the eikonal equation can be solved by using multiple methods to give

  9. TMS communications hardware. Volume 2: Bus interface unit

    NASA Technical Reports Server (NTRS)

    Brown, J. S.; Hopkins, G. T.

    1979-01-01

    A prototype coaxial cable bus communication system used in the Trend Monitoring System to interconnect intelligent graphics terminals to a host minicomputer is described. The terminals and host are connected to the bus through a microprocessor-based RF modem termed a Bus Interface Unit (BIU). The BIU hardware and the Carrier Sense Multiple Access Listen-While-Talk protocol used on the network are described.

  10. A Robotic Communications Gateway for Ocean Observations

    NASA Astrophysics Data System (ADS)

    Orcutt, J. A.; Berger, J.; Laske, G.; Babcock, J.

    2015-12-01

    We describe a new technology that can provide real-time telemetry of sensor data from the ocean bottom. The breakthrough technology that makes this system possible is an autonomous surface vehicle called the Wave Glider developed by Liquid Robotics, Inc. of Sunnyvale, CA., which harvests wave and solar energy for motive and electrical power. The free-floating surface communications gateway uses a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The topside acoustics communications package is mounted in a shallow tow body, which uses a WHOI micro modem and a Benthos low frequency, directional transducer. A matching bottom side modem and transducer are mounted on the ocean bottom package. Tests of the surface gateway in 4000 m of water demonstrated an acoustic efficiency of approximately 256 bits/J. For example, it has the ability to send four channels of compressed, one sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.36 W and a latency of about three minutes. This gateway is used to send near-real-time data from a broadband ocean bottom seismic observatory; we are presently designing and constructing a seafloor package with a two-year operational life. We have found that for frequencies f where f<10mHz, 35mHz < f < 120mHz and f>~3Hz, the vertical component, seafloor system noise characteristics are generally superior to similar observatories on land. Increasing the density of these stations over the majority of the surface of Earth; that is, the oceans will greatly enhance the resolution of deep Earth structure and serve civil needs including tsunami warning. The robotic technology is readily applicable for other ocean observations.

  11. ADDOSS: Autonomously Deployed Deep-ocean Seismic System - Communications Gateway for Ocean Observatories

    NASA Astrophysics Data System (ADS)

    Laske, Gabi; Berger, Jon; Orcutt, John; Babcock, Jeff

    2014-05-01

    We describe an autonomously deployable, communications gateway designed to provide long-term and near real-time data from ocean observatories. The key features of this new system are its abilities to telemeter sensor data from the seafloor to shore without cables or moorings, and to be deployed without a ship, thereby greatly reducing life-cycle costs. The free-floating surface communications gateway utilizes a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The acoustics communications package is mounted in a shallow tow body which utilizes a WHOI micro modem and a Benthos low frequency, directional transducer. A matching modem and transducer is mounted on the ocean bottom package. Tests of the surface gateway in 4350 m of water demonstrated an acoustic efficiency of approximately 396 bits/J. For example, it has the ability to send 4 channels of compressed, 1 sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.15 W and a latency of less than 3 minutes. This gateway is used to send near real-time data from a broadband ocean bottom seismic observatory, first during short week-to-months long test deployments but will ultimately be designed for a two-year operational life. Such data from presently unobserved oceanic areas are critical for both national and international agencies in monitoring and characterizing earthquakes, tsunamis, and nuclear explosions. We present initial results from a two short-term OBS test deployments off-shore La Jolla, at water depths of 1000 m and of nearly 4000 m.

  12. LOAC (Light Optical Particle Counter): a new small aerosol counter with particle characterization capabilities for surface and airborne measurements

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Berthet, Gwenael; Jégou, Fabrice; Jeannot, Matthieu; Jourdain, Line; Dulac, François; Mallet, Marc; Dupont, Jean-Charles; Thaury, Claire; Tonnelier, Thierry; Verdier, Nicolas; Charpentier, Patrick

    2013-04-01

    The determination of the size distribution of tropospheric and stratospheric aerosols with conventional optical counters is difficult when different natures of particles are present (droplets, soot, mineral dust, secondary organic or mineral particles...). Also, a light and cheap aerosol counter that can be used at ground, onboard drones or launched under all kinds of atmospheric balloons can be very useful during specific events as volcanic plumes, desert dust transport or local pollution episodes. These goals can be achieved thanks to a new generation of aerosol counter, called LOAC (Light Optical Aerosol Counter). The instrument was developed in the frame of a cooperation between French scientific laboratories (CNRS), the Environnement-SA and MeteoModem companies and the French Space Agency (CNES). LOAC is a small optical particle counter/sizer of ~250 grams, having a low electrical power consumption. The measurements are conducted at two scattering angles. The first one, at 12°, is used to determine the aerosol particle concentrations in 19 size classes within a diameter range of 0.3-100 micrometerers. At such an angle close to forward scattering, the signal is much more intense and the measurements are the least sensitive to the particle nature. The second angle is at 60°, where the scattered light is strongly dependent on the particle refractive index and thus on the nature of the aerosols. The ratio of the measurements at the two angles is used to discriminate between the different types of particles dominating the nature of the aerosol particles in the different size classes. The sensor particularly discriminates wet or liquid particles, soil dust and soot. Since 2011, we have operated LOAC in various environments (Arctic, Mediterranean, urban and peri-urban…) under different kinds of balloons including zero pressure stratospheric, tethered, drifting tropospheric, and meteorological sounding balloons. For the last case, the total weight of the gondola including the PTU sonde, transmission and batteries is below 1 kg. The results obtained during these flights and related campaigns such as the ground-based winter campaign Paris-Fog in Ile de France (fog life circle) and the Pre-ChArMEx/TRAQA summer campaign on the French Mediterranean coast will be presented, as well as future campaigns in which LOAC is involved, especially ChArMEx, (flights in the lower troposphere above the Mediterranean Sea), and Strateole (long duration flights in the tropical stratosphere). Balloon operation of LOAC will tentatively been shown during EGU.

  13. Line-of-Sight Data Link Test Set

    DTIC Science & Technology

    1976-06-01

    spheric layer model for layer refraction or a surface reflectivity model for ground reflection paths. Measurement of the channel impulse response...the model is exercised over a path consisting of only a constant direct component. The test would consist of measuring the modem demodulator bit...direct and a fading direct component. The test typically would consist of measuring the bit error-rate over a range of average signal-to-noise

  14. AGARD Bulletin Technical Programme 1986.

    DTIC Science & Technology

    1985-08-01

    basic research findings are being exploited by the pharmaceutical industry to develop new performance enhancing drugs with limited side effects and to... effects of nutrients on performance will also be considered. SHORT COURSE ( K Subject to final approval by the National Delegates Board at its Fall...coordinated with the AVP. WORKING GROUP The EPP will initiate Working Group-02 on "Near Water Propagation Effects and Modem System Adaptation". This

  15. Wireless, Acoustically Linked, Undersea, Magnetometer Sensor Network

    DTIC Science & Technology

    2010-06-01

    Hull Street, San Diego, CA 92152 mihajlo.tomic@navy.mil, sullivap@spawar.navy.mil, keyko.mcdonald.navy.mil Abstract—This paper presents a magnetometer...sensor node design that consists of a He3 nuclear precession total-field magne- tometer, data acquisition and recording electronics, and acoustic modem...detection range, thereby minimizing the overall number of required nodes to cover a given area. Given the aversion to continuously streaming data via the

  16. Implementation and Testing of the JANUS Standard with SSC Pacific’s Software-Defined Acoustic Modem

    DTIC Science & Technology

    2017-10-01

    Communications Outpost (FDECO) Innovative Naval Prototype (INP) Program by the Advanced Photonic Technologies Branch (Code 55360), Space and Naval Warfare...underwater acoustic communication operations with NATO and non-NATO military and civilian maritime assets. iv ACRONYMS SPAWAR Space and Naval Warfare...the center frequency [1]. The ease of implementation and proven robustness in harsh underwater acoustic communication channels paved the way for

  17. Meeting the Challenges of Regional Security

    DTIC Science & Technology

    1994-02-01

    targets over time, assessing strike damage, and, of course, developing up-to- date maps of crucial urban and industrial areas. Coupled with modem digital ...of huge diverse data bases is key to dissecting criminal infrastructures, and identifying relevant regional and global linkages. New digital processing...cities). They can aid in reaction force planning and training. One 10-inch optical disc can easily store 25 (and display at any scale with 4- digit

  18. Arctic Remote Autonomous Measurement Platform Post CEAREX Engineering Report

    DTIC Science & Technology

    1990-11-01

    consists of an aluminum frame which houses and supports the various electronics modules. This structure is supported in- side a specially constructed... aluminum cylinder for deployment. At the lower end, mechanical and electrical terminations connect the sea cable and the salt water battery. At the...2. Temperature transducer ( Thermometrics ) 3. Pressure Transducer (Sensotec) 4. Processor (Baiscon) 5. A/D converter 6. FSK modem 7. Case and Frame 8

  19. A Proposed Time Transfer Experiment Between the USA and the South Pacific

    DTIC Science & Technology

    1991-12-01

    1 nanosecond, The corrected position will be traris~nitted by both the time transfer modem and the existing TV line sync dissemination process...communications satellite (AUSSAT K1) (Figure 5), With after-the- fact ephemeris correction , this is useful to the 20 nanosecond level. The second...spheric corrections will ultimately reduce ephemeris related time transfer errors to the 1 nanosecond level. The corrected position will be transmitted

  20. High Resolution X-Band SAR Constallation for Risk Management

    DTIC Science & Technology

    2000-10-01

    polarisation has been specified to two unique, alternative SAR-satellite designs which as no specific requirement exists for dual- polarisation combine...dispersion while Fig. 4a). beam -scanning; 5 azimuth power splitters which feed the sub- 2. An architecture borrowed from modem panels...resolution SAR constellation therefore forms an essential Polarisation HH (or VV) component of such an observation system which shall Mean/max revisit < 12/24

  1. Astronaut James Newman works with computers and GPS

    NASA Image and Video Library

    1993-09-20

    STS051-16-028 (12-22 Sept 1993) --- On Discovery's middeck, astronaut James H. Newman, mission specialist, works with an array of computers, including one devoted to Global Positioning System (GPS) operations, a general portable onboard computer displaying a tracking map, a portable audio data modem and another payload and general support computer. Newman was joined by four other NASA astronauts for almost ten full days in space.

  2. Breaking Down the Digital Walls: Learning To Teach in a Post-Modem World. SUNY Series, Education and Culture: Critical Factors in the Formation of Character and Community in American Life.

    ERIC Educational Resources Information Center

    Burniske, R. W.; Monke, Lowell

    This book describes how two teachers, half a world apart, created collaborative Internet projects for high school students worldwide. Projects helped develop critical thinking, genuine dialogue, and global understanding in the classroom. Through the development of curricular projects linking classrooms in Malaysia, Japan, Iowa, South Africa, and…

  3. 1982 Federal Acquisition Research Symposium, Integrating Theory and Experience: The Acquisition Research Connection

    DTIC Science & Technology

    1982-05-07

    Technology. March 1981. 114(157. 16-17. Guetzkow, Harold, Kotler , Philip , i Schultz, Randall L, Simulation in social and administrative science...Primitive. Arcnaic and Modem Economies. Edited bv George Dalton. Beacon Press, Boston, 1968, |16) WOGAMAN, PHILIP I,, Tie Great Economic Debate: An...Department of Energy Washington, DC 20585 Mr. Philip M. King Grant and Contract Specialist National Science Foundation 1800 G Street, NW Washington

  4. Construction of a Chemical Sensor/Instrumentation Package Using Fiber Optic and Miniaturization Technology

    NASA Technical Reports Server (NTRS)

    Newton, R. L.

    1999-01-01

    The objective of this research was to construct a chemical sensor/instrumentation package that was smaller in weight and volume than conventional instrumentation. This reduction in weight and volume is needed to assist in further reducing the cost of launching payloads into space. To accomplish this, fiber optic sensors, miniaturized spectrometers, and wireless modems were employed. The system was evaluated using iodine as a calibration analyte.

  5. New Trends in Two-Way Time and Frequency Transfer via Satellite

    DTIC Science & Technology

    1999-12-01

    Recent developments performed with SATRE two-way time transfer ( TWSTFT ) modems resulted in significant performance upgrades and operational...improvements of the TWSTFT method These are aimed to reduce : manpower effort and to provide reliable, real-time data via a centralized monitoring and...collection have been used throughout the experiment INTRODUCTION Two-Way Time and Frequency Transfer via Satellite ( TWSTFT ) is a well established method to

  6. Cooperative processing user interfaces for AdaNET

    NASA Technical Reports Server (NTRS)

    Gutzmann, Kurt M.

    1991-01-01

    A cooperative processing user interface (CUI) system shares the task of graphical display generation and presentation between the user's computer and a remote host. The communications link between the two computers is typically a modem or Ethernet. The two main purposes of a CUI are reduction of the amount of data transmitted between user and host machines, and provision of a graphical user interface system to make the system easier to use.

  7. Communication in Pipes Using Acoustic Modems that Provide Minimal Obstruction to Fluid Flow

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph (Inventor); Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Archer, Eric D. (Inventor)

    2016-01-01

    A plurality of phased array acoustic communication devices are used to communicate data along a tubulation, such as a well. The phased array acoustic communication devices employ phased arrays of acoustic transducers, such as piezoelectric transducers, to direct acoustic energy in desired directions along the tubulation. The system is controlled by a computer-based controller. Information, including data and commands, is communicated using digital signaling.

  8. Two-way satellite time transfer: Overview and recent developments

    NASA Technical Reports Server (NTRS)

    Dejong, Gerrit

    1994-01-01

    The experiment using small earth stations for transatlantic two-way satellite time transfer between the USA and Germany has had its 10th anniversary this year. Pseudo-random noise coded time signals were phase modulated and demodulated at each station using a modem. Recently, during the last two weeks of Aug. 1993, six European time laboratories have used the INTELSAT 307E satellite for line-up tests and preliminary time transfer sessions using the same type of MITREX modem. The need for a uniform format for the exchange of data was felt heavily after these sessions. This problem was foreseen and addressed in international working parties. During Apr. 1993, in Task Group 7/2 of the ITU Radiocommunication Sector, a very intense discussion has taken place about what procedure should be recommended for TWSTFT and what items the header and data lines of the resulting data fields should contain. A difficulty is that two different methods of calibration of the earth station delays exist which result in different sets of delay data to be exchanged. Further study and discussions are necessary. Also, a meeting of the CCDS Working Group on TWSTFT addressed this in Oct. 1993. The outcome of the discussions and the prospect for future developments are presented.

  9. Intranet and Internet metrological workstation with photonic sensors and transmission

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Dybko, Artur

    1999-05-01

    We describe in this paper a part of a telemetric network which consists of a workstation with photonic measurement and communication interfaces, structural fiber optic cabling (10/100BaseFX and CAN-FL), and photonic sensors with fiber optic interfaces. The station is equipped with direct photonic measurement interface and most common measuring standards converter (RS, GPIB) with fiber optic I/O CAN bus, O/E converters, LAN and modem ports. The station was connected to the Intranet (ipx/spx) and Internet (tcp/ip) with separate IP number and DNS, WINS names. Virtual measuring environment system program was written specially for such an Intranet and Internet station. The measurement system program communicated with the user via a Graphical User's Interface (GUI). The user has direct access to all functions of the measuring station system through appropriate layers of GUI: telemetric, transmission, visualization, processing, information, help and steering of the measuring system. We have carried out series of thorough simulation investigations and tests of the station using WWW subsystem of the Internet. We logged into the system through the LAN and via modem. The Internet metrological station works continuously under the address http://nms.ipe.pw.edu.pl/nms. The station and the system hear the short name NMS (from Network Measuring System).

  10. Web servlet-assisted, dial-in flow cytometry data analysis.

    PubMed

    Battye, F

    2001-02-01

    The obvious benefits of centralized data storage notwithstanding, the size of modern flow cytometry data files discourages their transmission over commonly used telephone modem connections. The proposed solution is to install at the central location a web servlet that can extract compact data arrays, of a form dependent on the requested display type, from the stored files and transmit them to a remote client computer program for display. A client program and a web servlet, both written in the Java programming language, were designed to communicate over standard network connections. The client program creates familiar numerical and graphical display types and allows the creation of gates from combinations of user-defined regions. Data compression techniques further reduce transmission times for data arrays that are already much smaller than the data file itself. For typical data files, network transmission times were reduced more than 700-fold for extraction of one-dimensional (1-D) histograms, between 18 and 120-fold for 2-D histograms, and 6-fold for color-coded dot plots. Numerous display formats are possible without further access to the data file. This scheme enables telephone modem access to centrally stored data without restricting flexibility of display format or preventing comparisons with locally stored files. Copyright 2001 Wiley-Liss, Inc.

  11. Using perceptual rules in interactive visualization

    NASA Astrophysics Data System (ADS)

    Rogowitz, Bernice E.; Treinish, Lloyd A.

    1994-05-01

    In visualization, data are represented as variations in grayscale, hue, shape, and texture. They can be mapped to lines, surfaces, and glyphs, and can be represented statically or in animation. In modem visualization systems, the choices for representing data seem unlimited. This is both a blessing and a curse, however, since the visual impression created by the visualization depends critically on which dimensions are selected for representing the data (Bertin, 1967; Tufte, 1983; Cleveland, 1991). In modem visualization systems, the user can interactively select many different mapping and representation operations, and can interactively select processing operations (e.g., applying a color map), realization operations (e.g., generating geometric structures such as contours or streamlines), and rendering operations (e.g., shading or ray-tracing). The user can, for example, map data to a color map, then apply contour lines, then shift the viewing angle, then change the color map again, etc. In many systems, the user can vary the choices for each operation, selecting, for example, particular color maps, contour characteristics, and shading techniques. The hope is that this process will eventually converge on a visual representation which expresses the structure of the data and effectively communicates its message in a way that meets the user's goals. Sometimes, however, it results in visual representations which are confusing, misleading, and garish.

  12. Pi/4-QPSK modems for satellite sound/data broadcast systems

    NASA Technical Reports Server (NTRS)

    Liu, Chia-Liang; Feher, Kamilo

    1991-01-01

    The use of pi/4-quadrature phase-shift keying (QPSK) modems for satellite sound broadcast systems (SSBS) broadcasting to mobile or portable receivers is proposed. Three different differential detectors (including the FM-discriminator followed by integrate-sample-and-dump filter) and a novel coherent detector are discussed. The degradation caused by the frequency offset between the local oscillator (LO) and the unmodulated carrier (CR) in the baseband differential detector is studied. The performance of both coherently and differentially detected pi/4-QPSK in a Gaussian channel is also studied. It is shown that with a frequency offset of more than 3 percent of the symbol rate, the performance degradation is more than 1 dB at 0.0001. The out-of-band power of the nonlinearly amplified bandlimited pi/4-QPSK signals is reduced from -13 dB to -37 dB if a 2-dB output back-off amplifier is used instead of a hardlimiter. The performance of the pi/4-QPSK is equivalent to that of QPSK, although the pi/4-QPSK has the advantage of less spectrum restoration after nonlinear amplification. The coherent demodulator and differential decoder avoid the three-level detection and achieve the same bit-error-rate performance as DEQPSK with a simple circuit.

  13. Ka-Band, Multi-Gigabit-Per-Second Transceiver

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.; Smith, Francis J.; Harris, Johnny M.; Landon, David G.; Haddadin, Osama S.; McIntire, William K.; Sun, June Y.

    2011-01-01

    A document discusses a multi-Gigabit-per-second, Ka-band transceiver with a software-defined modem (SDM) capable of digitally encoding/decoding data and compensating for linear and nonlinear distortions in the end-to-end system, including the traveling-wave tube amplifier (TWTA). This innovation can increase data rates of space-to-ground communication links, and has potential application to NASA s future spacebased Earth observation system. The SDM incorporates an extended version of the industry-standard DVB-S2, and LDPC rate 9/10 FEC codec. The SDM supports a suite of waveforms, including QPSK, 8-PSK, 16-APSK, 32- APSK, 64-APSK, and 128-QAM. The Ka-band and TWTA deliver an output power on the order of 200 W with efficiency greater than 60%, and a passband of at least 3 GHz. The modem and the TWTA together enable a data rate of 20 Gbps with a low bit error rate (BER). The payload data rates for spacecraft in NASA s integrated space communications network can be increased by an order of magnitude (>10 ) over current state-of-practice. This innovation enhances the data rate by using bandwidth-efficient modulation techniques, which transmit a higher number of bits per Hertz of bandwidth than the currently used quadrature phase shift keying (QPSK) waveforms.

  14. Ultra Small Aperture Terminal for Ka-Band SATCOM

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto; Reinhart, Richard; Lee, Richard; Simons, Rainee

    1997-01-01

    An ultra small aperture terminal (USAT) at Ka-band frequency has been developed by Lewis Research Center (LeRC) for data rates up to 1.5 Mbps in the transmit mode and 40 Mbps in receive mode. The terminal consists of a 35 cm diameter offset-fed parabolic antenna which is attached to a solid state power amplifier and low noise amplifier. A single down converter is used to convert the Ka-band frequency to 70 MHz intermediate frequency (IF). A variable rate (9.6 Kbps to 10 Mbps) commercial modem with a standard RS-449/RS-232 interface is used to provide point-to-point digital services. The terminal has been demonstrated numerous times using the Advanced Communications Technology Satellite (ACTS) and the 4.5 in Link Evaluation Terminal (LET) in Cleveland. A conceptual design for an advanced terminal has also been developed. This advanced USAT utilizes Microwave Monolithic Integrated Circuit (MMIC) and flat plate array technologies. This terminal will be self contained in a single package which will include a 1 watt solid state amplifier (SSPA), low noise amplifier (LNA) and a modem card located behind the aperture of the array. The advanced USAT will be light weight, transportable, low cost and easy to point to the satellite. This paper will introduce designs for the reflector based and array based USAT's.

  15. Early Evolution of Earth's Geochemical Cycle and Biosphere: Implications for Mars Exobiology

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.; Chang, Sherwood (Technical Monitor)

    1997-01-01

    Carbon (C) has played multiple key roles for life and its environment. C has formed organics, greenhouse gases, aquatic pH buffers, redox buffers, and magmatic constituents affecting plutonism and volcanism. These roles interacted across a network of reservoirs and processes known as the biogeochemical C cycle. Changes in the cycle over geologic time were driven by increasing solar luminosity, declining planetary heat flow, and continental and biological evolution. The early Archean C cycle was dominated by hydrothermal alteration of crustal rocks and by thermal emanations of CO2 and reduced species (eg., H2, Fe(2+) and sulfides). Bioorganic synthesis was achieved by nonphotosynthetic CO2-fixing bacteria (chemoautotrophs) and, possibly, bacteria (organotrophs) utilizing any available nonbiological organic C. Responding both to abundant solar energy and to a longterm decline in thermal sources of chemical energy and reducing power, the blaspheme first developed anoxygenic photosynthesis, then, ultimately, oxygenic photosynthesis. O2-photosynthesis played a central role in transforming the ancient environment and blaspheme to the modem world. The geochemical C cycles of early Earth and Mars were quite similar. The principal differences between the modem C cycles of these planets arose during the later evolution of their heat flows, crusts, atmospheres and, perhaps, their blasphemes.

  16. Improvement in the technological feasibility of a web-based dietary survey system in local settings.

    PubMed

    Jung, Hyun Ju; Lee, Sang Eun; Kim, Dongwoo; Noh, Hwayoung; Song, Sujin; Kang, Minji; Song, Yoon Ju; Paik, Hee-Young

    2015-01-01

    The feasibility of a dietary survey tool is crucial for successful nutritional assessment via a community survey and for nutritional epidemiology. In 2012, we identified a newly developed computerized dietary survey system, the Diet Evaluation System (DES), which could be successfully applied to a community survey delivered during home visits using notebook computers when the internet environment was adequate, using either a WiBro modem or a smartphone as a tethered modem. In 2013, we retested DES feasibility using various mobile devices and in a larger number of subjects. We conducted a total of 430 interviews, representing two for each of 215 subjects of various ages, using tablet personal computers (PCs) and laptops. In addition, a group discussion with the interviewers was conducted. The interview success rate was improved to 84% (compared to 67% in 2012). Completing each interview took 14 min 1 s, and data processing was conducted automatically. The subjects' age, gender, and the type of mobile device used influenced the DES interview time. This study implies that the DES is an effective one-stop dietary survey system for use in a local setting. The interviewers' group discussion revealed that a one-stop system using the DES is convenient and that DES optimization for tablet PCs and continued database updating is needed.

  17. Evaluation of the MODIS Aerosol Retrievals over Ocean and Land during CLAMS.

    NASA Astrophysics Data System (ADS)

    Levy, R. C.; Remer, L. A.; Martins, J. V.; Kaufman, Y. J.; Plana-Fattori, A.; Redemann, J.; Wenny, B.

    2005-04-01

    The Chesapeake Lighthouse Aircraft Measurements for Satellites (CLAMS) experiment took place from 10 July to 2 August 2001 in a combined ocean-land region that included the Chesapeake Lighthouse [Clouds and the Earth's Radiant Energy System (CERES) Ocean Validation Experiment (COVE)] and the Wallops Flight Facility (WFF), both along coastal Virginia. This experiment was designed mainly for validating instruments and algorithms aboard the Terra satellite platform, including the Moderate Resolution Imaging Spectroradiometer (MODIS). Over the ocean, MODIS retrieved aerosol optical depths (AODs) at seven wavelengths and an estimate of the aerosol size distribution. Over the land, MODIS retrieved AOD at three wavelengths plus qualitative estimates of the aerosol size. Temporally coincident measurements of aerosol properties were made with a variety of sun photometers from ground sites and airborne sites just above the surface. The set of sun photometers provided unprecedented spectral coverage from visible (VIS) to the solar near-infrared (NIR) and infrared (IR) wavelengths. In this study, AOD and aerosol size retrieved from MODIS is compared with similar measurements from the sun photometers. Over the nearby ocean, the MODIS AOD in the VIS and NIR correlated well with sun-photometer measurements, nearly fitting a one-to-one line on a scatterplot. As one moves from ocean to land, there is a pronounced discontinuity of the MODIS AOD, where MODIS compares poorly to the sun-photometer measurements. Especially in the blue wavelength, MODIS AOD is too high in clean aerosol conditions and too low under larger aerosol loadings. Using the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative code to perform atmospheric correction, the authors find inconsistency in the surface albedo assumptions used by the MODIS lookup tables. It is demonstrated how the high bias at low aerosol loadings can be corrected. By using updated urban/industrial aerosol climatology for the MODIS lookup table over land, it is shown that the low bias for larger aerosol loadings can also be corrected. Understanding and improving MODIS retrievals over the East Coast may point to strategies for correction in other locations, thus improving the global quality of MODIS. Improvements in regional aerosol detection could also lead to the use of MODIS for monitoring air pollution.

  18. Audiovisual signal compression: the 64/P codecs

    NASA Astrophysics Data System (ADS)

    Jayant, Nikil S.

    1996-02-01

    Video codecs operating at integral multiples of 64 kbps are well-known in visual communications technology as p * 64 systems (p equals 1 to 24). Originally developed as a class of ITU standards, these codecs have served as core technology for videoconferencing, and they have also influenced the MPEG standards for addressable video. Video compression in the above systems is provided by motion compensation followed by discrete cosine transform -- quantization of the residual signal. Notwithstanding the promise of higher bit rates in emerging generations of networks and storage devices, there is a continuing need for facile audiovisual communications over voice band and wireless modems. Consequently, video compression at bit rates lower than 64 kbps is a widely-sought capability. In particular, video codecs operating at rates in the neighborhood of 64, 32, 16, and 8 kbps seem to have great practical value, being matched respectively to the transmission capacities of basic rate ISDN (64 kbps), and voiceband modems that represent high (32 kbps), medium (16 kbps) and low- end (8 kbps) grades in current modem technology. The purpose of this talk is to describe the state of video technology at these transmission rates, without getting too literal about the specific speeds mentioned above. In other words, we expect codecs designed for non- submultiples of 64 kbps, such as 56 kbps or 19.2 kbps, as well as for sub-multiples of 64 kbps, depending on varying constraints on modem rate and the transmission rate needed for the voice-coding part of the audiovisual communications link. The MPEG-4 video standards process is a natural platform on which to examine current capabilities in sub-ISDN rate video coding, and we shall draw appropriately from this process in describing video codec performance. Inherent in this summary is a reinforcement of motion compensation and DCT as viable building blocks of video compression systems, although there is a need for improving signal quality even in the very best of these systems. In a related part of our talk, we discuss the role of preprocessing and postprocessing subsystems which serve to enhance the performance of an otherwise standard codec. Examples of these (sometimes proprietary) subsystems are automatic face-tracking prior to the coding of a head-and-shoulders scene, and adaptive postfiltering after conventional decoding, to reduce generic classes of artifacts in low bit rate video. The talk concludes with a summary of technology targets and research directions. We discuss targets in terms of four fundamental parameters of coder performance: quality, bit rate, delay and complexity; and we emphasize the need for measuring and maximizing the composite quality of the audiovisual signal. In discussing research directions, we examine progress and opportunities in two fundamental approaches for bit rate reduction: removal of statistical redundancy and reduction of perceptual irrelevancy; we speculate on the value of techniques such as analysis-by-synthesis that have proved to be quite valuable in speech coding, and we examine the prospect of integrating speech and image processing for developing next-generation technology for audiovisual communications.

  19. The DTIC Review. Information Terrorism. Volume 5, Number 1

    DTIC Science & Technology

    2000-03-01

    ABSTRACT: (U) This document describes a PERSONAL AUTHORS: Llinas, James; proposed program of research into theories, Bisantz, Ann; Drury , Colin ; Seong...management computer. Before he finished he transferred more than $12 million to other banks and had access to the $500 billion daily transfer account . 3 By the...modem. The General Accounting Office recently estimated that Pentagon computers experience some 250,000 hacker attacks per year and 5 that 65 percent

  20. Army Communicator. Volume 33, Number 3, Summer 2008. WIN-T: Increasing the Power of Battlefield Communications

    DTIC Science & Technology

    2008-01-01

    Increment 2 will provide unprecedented network connectivity for Brigade Combat Teams while they quickly traverse the battlefield during fast moving... fast . As you know, just working with the Directorate of Information Management with your computer, you need constant patches, up- grades, updates...designed for fast acquisition and requisition. The modem will reacquire bursts within a second for short duration or intermittent blockages. Should the user

  1. Approaches to Polymer Curing and Imaging Via the In Situ Generation of a Catalyst

    DTIC Science & Technology

    1992-04-20

    polyimide can be formulated from a polyamic acid derivative and a photo- precursor of base. Of particular interest are systems that incorporate chemical...amplification. In these systems the initial radiation induced proc- ess, photogeneration of the acid or base catalyst within the polymer film, is...different, new systems better suited for the high demands of modem microlithography have been developed. Issues of particular relevance in the design of

  2. Program Analysis and Design Requirements for tne National Science Center

    DTIC Science & Technology

    1991-02-01

    shell of an old exposition building with secondhand furniture to display exhibit items, to the Ontario Science Center, which is a more modem building...Storage Area Pigeonhole storage cabinets for children’s school books , coats, and boots are provided at the Indianapolis Center. The Ontario center...used shopping carts for school groups to store their coats and books . They do not work well according to center staff and are cumbersome and unsightly

  3. Bridging the Capability Gap for Battle Command On-the-Move

    DTIC Science & Technology

    2005-06-01

    FDM) and synchronous Time Division Multiplexing (TDM) network components. This advantage will become further realized once mobile satellite modem... synchronize the initial network timing . Once a NM receives this beacon, it reports the measured receive signal strength back to the NC using the NM’s...in certain areas of the world. Due to M4’s synchronous network connections, link engineering to manage required distributed network timing is often

  4. Modern Inertial and Satellite Navigation Systems

    DTIC Science & Technology

    1994-05-02

    rotor spins, the harder it is to disturb it. This technique is called spin stabilization and it is commonly used for communication satellites. Moder... using a generalization of the complex number called the quaternion . Modem Inertial and Satellite Navigation Systems page 32. 4.2 Exdrson in Pincile...length by an integer. Positive feedback arises from the use of a lasing medium, a gas, liquid, crystal ions, or any of a number of other possibilities

  5. Counternarcotics Strategies: Effects on Afghanistan Hearts and Minds

    DTIC Science & Technology

    2010-03-16

    the modem world, what little its remoteness may realize. The only period of peaceful centralized rule during its long history was during the rule of...encouraging the growth of pomegranates and of saffron rice as alternative crops that draw buyers outside of Afghanistan. ඌ The present strength of...that a careful and more sophisticated approach must be taken rather than a rush to reward those with criminal histories in light of misunderstood

  6. Second Report of the Multirate Processor (MRP) for Digital Voice Communications.

    DTIC Science & Technology

    1982-09-30

    machine are: * two arithmetic logic units (ALUs)-one for data processing, and the other for address generation, * two memorys -6144 words (70 bits per word...of program memory , and 6094 words (16 bits per word) of data memory , q * input/output through modem and teletype, -15 .9 S-;. KANG AND FRANSEN Table...provides a measure of intelligibility and allows one to evaluate the discriminability of six distinctive features: voicing, nasality, sustention

  7. Performance Results of CMMI-Based Process Improvement

    DTIC Science & Technology

    2006-08-01

    SW-CMM assessment. The statement in row three of Table 7 is from DB Systems GmbH, a major IT provider for the transport and travel industry. As...Its Products Motorola India Electronics Ltd ( MIEL ) was founded in 1991 and had 60 employees in the first year. The organization had grown to 800...practices. MIEL develops and maintains telecom software for Motorola cell phone products, wireless networks, broad band cable modems, and automotive and

  8. Efficient Processing of Acoustic Signals for High Rate Information Transmission over Sparse Underwater Channels

    DTIC Science & Technology

    2016-09-02

    the fractionally-spaced channel estimators and the short feedforward equalizer filters . Receiver algorithm is applied to real data transmitted at 10...multichannel decision-feedback equalizer (DFE)[1]. This receiver consists of a bank of adaptive feedforwad filters , one per array element, followed by a...decision-feedback filter . It has been implemented in the prototype high-rate acoustic modem developed at the Woods Hole Oceanographic Institution, and

  9. Time/Frequency Relationships for an FFT-Based Acoustic Modem

    DTIC Science & Technology

    2010-09-01

    Jenkins II 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING... seawater , and a fluid- like bottom composed of quartz sand. From [11] ............................................18  Table 3.  Transmission loss at the...in St. Andrew’s Bay, Florida [4]. The goal of this sea testing was to observe the effects of natural and man-made noise on network performance in a

  10. Social Structures Affecting Army Performance

    DTIC Science & Technology

    2007-06-01

    hegemonic masculinity in modem war. They argue that the emergence of a new set of state-based practices of war-making during ’the age of democratic...Kestnbaum, M., & Mann, E. (2004, August). Arms and the Man: War and Hegemonic Masculinity at the Turn of the Eighteenth Century. Paper presented at the 9 9...heterosexual and masculine culture of the military and its role in creating and sustaining gender and sexuality stratification in American society, and the

  11. Understanding Attitudes on Gender and Training at the United States Air Force Academy

    DTIC Science & Technology

    2005-01-01

    hypotheses ................................................. 44 3. Correlations among sexism scales and impact of women on the physical fitness standards...fitness standards. Specifically, levels of sexism regarding women in society, the roles of women in combat, women and certain military jobs, and the ...at the United States Air Force Academy. Items 1 to 8 are the Modem Sexism Scale (MSS) developed by Swim, Aikin, Hall, and Hunter (1995), items 9-12

  12. Performance Evaluation of a Prototype Underwater Short-Range Acoustic Telemetry Modem

    DTIC Science & Technology

    2010-09-01

    SR560 Low-Noise Preamplifier – Hewlett Packard (HP) 3314A Function Generator – Phillips PM 3384 Oscilloscope – Dell Latitude D620 notebook...two Stanford Research Systems SR560 low-noise preamplifiers , an IOtech Personal DAQ/3000 Series data acquisition box (DAQ), an HP 3314A function...mono frequency measurements were two B&K 8103 hydrophones, two Stanford Research Systems SR560 low-noise preamplifiers , an IOtech Personal DAQ/3000

  13. Balancing Information Analysis and Decision Value: A Model to Exploit the Decision Process

    DTIC Science & Technology

    2011-12-01

    technical intelli- gence e.g. signals and sensors (SIGINT and MASINT), imagery (!MINT), as well and human and open source intelligence (HUMINT and OSINT ...Clark 2006). The ability to capture large amounts of da- ta and the plenitude of modem intelligence information sources provides a rich cache of...many tech- niques for managing information collected and derived from these sources , the exploitation of intelligence assets for decision-making

  14. Prime Item Development Specification for IFF Transponder RT-1063B/APX101(V) CI 650100A. Part I. Revision A.

    DTIC Science & Technology

    1977-08-18

    Antenna Input/Output modem " 𔃾"TELEDYVNE ELECTRONICS DOCUMENT NO. AECA 77-1 DATE March 3j, 1977 REVISI_ A, (Aug 18, 1977) PAGE 1.1-6. OFRL-_.6 30. 2 Mode...ISOLATION REQUIRE- MENTS: None 12. RISE TIME: N/A 13. FALL TIME: N/A 14. PULSE CHARACTER- ISTICS: N/A 15. CAUTION LIGHT ON: ? 56K ohms (Open) 16. CAUTION

  15. Integrated AUTODIN System Architecture Report. Part 2.

    DTIC Science & Technology

    1979-03-01

    Link Modes Protocols and end-to- end host protocols Codes ASCII, ITA#2 ASCII, Others (Trans- parent to network) Speeds 45 thru 4800 bps 110 bps thru 56K ...service facilities such as AMPEs, subscriber access lines, modems , multiplexers, concentrators, interface development to include software design and...Protocol) CODES - ASCII and ITA#2 (others transparent) SPEEDS - 45.5bps - 56K bps FORMATS - AUTODIN II Segment Formats, JANAP 128, ACP 126/127, DOI 103

  16. Feasibility Study for an Air Force Environmental Model and Data Exchange. Volume 1. Model and Data Requirements with Recommendations.

    DTIC Science & Technology

    1983-07-01

    CC6600 FOR 64CPU 56K N s0 so AT123D 102 W L IBM4360 FOR 2 K CLEARY GROUN WATER FLOW 240 C FOR " CLEARY MASS TRANSPORT 222 U C FOR Y *DIURNAL 102 W H L...user support. $250,000 Computer Hardware Principally acquisition of terminals. printers, and modems for distribution to the user commnunity. $100,000

  17. Case Study Analysis of United States Navy Financial Field Activity

    DTIC Science & Technology

    1991-06-01

    and must be continued in order to keep providing quality base administration. The replacement of ten inch magnetic disk with modem data storage media...Equipment Priority: 3 Total Required Total Funded Shortfall Total Funding: 847K 791K 56K Narrative Description of Requirements: This requirement is...Equipment Priority: 3 Total Required Total Funded Shortfall Total Funding: 847K 791K 56K Narrative Description of Requirements: This deficiency would

  18. Armed Forces and National Development in the Case of the Republic of Indonesia

    DTIC Science & Technology

    1990-03-01

    DEVELOPMENT ........... 9 E. THE TARGETS OF NATIONAL DEVELOPMENT ............. 9 Ill. THE HISTORY OF THE INDONESIAN ARMED FORCES .......... 13 A. THE...stability in the economics and politics of Taiwan. Similarly, in the course of history of the nation’s struggle to uphold the proclamation of independence...common history , tradition and culture. Development refers to socio- demographic, structural, and value changes from traditional to modem. It also refers

  19. SDR-Ready Standardized Waveforms for Tactical VHF and UHF Communications for NATO

    DTIC Science & Technology

    2010-09-01

    and noncoherent receiver. Both simulator and modem implementation of the NBWF have been undertaken at CRC Canada. Testing using RF channel...20kbps (100ms interleaver, coherent receiver) User to Legacy 16kbps FSK with Noncoherent Receiver (courtesy J. Nieto, Harris Corp., Rochester NY...NBWF NBWF 20kbps (100ms interleaver, coherent receiver) ST4204 16kbps FSK with noncoherent receiver (courtesy J. Nieto, Harris Corp., Rochester NY

  20. Preparing the Plate Boundary Observatory GNSS Network for the Future

    NASA Astrophysics Data System (ADS)

    Austin, K. E.; Walls, C. P.; Dittman, T.; Mann, D.; Boyce, E. S.; Basset, A.; Woolace, A. C.; Turner, R.; Lawrence, S.; Rhoades, S.; Pyatt, C.; Willoughby, H.; Feaux, K.; Mattioli, G. S.

    2017-12-01

    The EarthScope Plate Boundary Observatory (PBO) GNSS network, funded by the NSF and operated by UNAVCO, is comprised of 1100 permanent GPS and GNSS stations spanning three principal tectonic regimes and is administered by distinct management. The GPS-only network was initially designed for daily data file downloads primarily for tectonic analysis. This low data volume requirement and circa-2004 IP-based cellular/VSat modems provided significant freedom for station placement and enabled science-targeted installation of stations in some of the most remote and geologically interesting areas. Community requests for high-rate data downloads for GNSS seismology, airborne LiDAR surveys, meteorological/GNSS/seismic real-time data flow and other demands, however, require significantly increased bandwidth beyond the 5-20 kB/s transfer rates that were needed as part of the original design. Since the close of construction in September 2008, PBO enhancements have been implemented through additional funding by the NSF (ARRA/Cascadia), NOAA, and NASA and in collaboration with stakeholders such as Caltrans, ODOT, Scripps, and the USGS. Today, only 18 of the original cell modems remain, with 601 upgraded cell modems providing 3G/4G/LTE data communications that support transfer rates ranging from 80-400 kB/s. Radio network expansion and upgrades continue to harden communications using both 2.4 GHz and 5.8 GHz radios. 78 VSAT and 5 manual download sites remain. PBO-wide the network capabilities for 1 Hz & 5 Hz downloads or low latency 1 Hz streaming are 85%, 80% and 65% of PBO stations, respectively, with 708 active 1 Hz streams. Vaisala meteorological instruments are located at 140 sites most of which stream GPS/Met data in real time. GPS-only receivers are being replaced with GNSS receivers and antennas. Today, there are 279 stations in the PBO network with either GLONASS enabled Trimble NetR9 or full GNSS constellation Septentrio PolaRx5 receivers. Just as the scale and geographical density of the PBO project has opened up new and unexpected avenues for geophysical research across disciplines (e.g. atmosphere, meteorology, snow pack, tides, vegetation growth, drought monitoring, etc.), the coming decade under the NGEO banner will undoubtedly present new opportunities as the network continues to be modernized.

  1. New technological developments provide deep-sea sediment density flow insights: the Monterey Coordinated Canyon Experiment

    NASA Astrophysics Data System (ADS)

    O'Reilly, T. C.; Kieft, B.; Chaffey, M. R.; Wolfson-Schwehr, M.; Herlien, R.; Bird, L.; Klimov, D.; Paull, C. K.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Caress, D. W.; Sumner, E. J.; Simmons, S.; Parsons, D. R.; Talling, P.; Rosenberger, K. J.; Xu, J.; Maier, K. L.; Gales, J. A.

    2017-12-01

    The Monterey Coordinated Canyon Experiment (CCE) deployed an array of instruments along the Monterey Canyon floor to characterize the structure, velocity and frequency of sediment flows. CCE utilized novel technologies developed at MBARI to capture sediment flow data in unprecedented detail. 1. The Seafloor Instrument Node (SIN) at 1850 meters depth housed 3 ADCPs at 3 different frequencies, CTD, current meter, oxygen optode, fluorometer/backscatter sensor, and logged data at 10 second intervals or faster. The SIN included an acoustic modem for communication with shore through a Wave Glider relay, and provided high-resolution measurements of three flow events during three successive deployments over 1.5 years. 2. Beachball-sized Benthic Event Detectors (BEDs) were deployed on or under the seafloor to measure the characteristics of sediment density flows. Each BED recorded data from a pressure sensor and a 3-axis accelerometer and gyro to characterize motions during transport events (e.g. tumble vs rotation). An acoustic modem capable of operating through more than a meter of sediment enabled communications with a ship or autonomous surface vehicle. Multiple BEDs were deployed at various depths in the canyon during CCE, detecting and measuring many transport events; one BED moved 9 km down canyon in 50 minutes during one event. 3. Wave Glider Hot Spot (HS), equipped with acoustic and RF modems, acted as data relay between SIN, BEDs and shore, and acoustically located BEDs after sediment density flows.. In some cases HS relayed BED motion data to shore within a few hours of the event. HS provided an acoustic console to the SIN, allowing shore-based users to check SIN health and status, perform maintenance, etc. 4. Mapping operations were conducted 4 times at the SIN site to quantify depositional and erosional patterns, utilizing a prototype ultra-high-resolution mapping system on the ROV Doc Ricketts. The system consists of a 400-kHz Reson 7125 multibeam sonar, a 3DatDepth SL1 subsea LiIDAR, two stereo color cameras, and a Kearfott SeaDevil INS. At a survey altitude of 3 m above the bed, the mapping system provides 5-cm resolution multibeam bathymetry, 1-cm resolution lidar bathymetry, and 2-mm resolution photomosaics. We will describe the design and full capabilities of these novel systems.

  2. Survey of Diego Garcia (BIOT) as a Remote Client for Telemedical Services

    DTIC Science & Technology

    1996-05-28

    4.1 4.2 PICASSO Still-Image Phone ........................................................................... 4.1 4.3 Enhanced CU- SeeMe ...PICASSO sites. Page 4.2 CHAPTER FOUR: Current Telemedical Resources on Diego Garcia 4.3 Enhanced CU- SeeMe A Connectix QuickCam digital camera, the latest...White Pine version of Enhanced CU- SeeMe software and a US Robotics 14.4kbps/28.8 kbps modem were provided to the staff of the Health Services

  3. Advances in Integrating Autonomy with Acoustic Communications for Intelligent Networks of Marine Robots

    DTIC Science & Technology

    2013-02-01

    Sonar AUV #Environmental Sampling Environmental AUV +name : string = OEX Ocean Explorer +name : string = Hammerhead Iver2 +name : string = Unicorn ...executable» Google Earth Bluefin 21 AUV ( Unicorn ) MOOS Computer GPS «serial» Bluefin 21 AUV (Macrura) MOOS Computer «acoustic» Micro-Modem «wired...Computer Bluefin 21 AUV ( Unicorn ) MOOS Computer NURC AUV (OEX) MOOS Computer Topside MOOS Computer «wifi» 5.0GHz WiLan «acoustic» Edgetech GPS

  4. JPRS Report, Soviet Union, Kommunist, No. 2, January 1988.

    DTIC Science & Technology

    1989-03-02

    Stavropolskoye Broiler Production i.e., a process of compensation for losses which occur as Association). the result of basic metabolism and work and, in...young The nutrition of modem man is to a large extent a people, growth. In the course of the digestion of variousThemnuromiseti oeen the ex istig...skimmed milk, approximately 60 percent of which con- master the standards of nutrition as any other type of sists of easily digestible rich protein of

  5. Military Rule and the Problem of Legitimacy: Peru, 1968-1975 and Argentina, 1976-1983

    DTIC Science & Technology

    1992-05-01

    national development. To develop, Peru needed to forge a modem industrial society as well as an efficient agrarian sector. The military’s first step was...while reserving certain ’key industrial sectors to the state." 11 The military government also developed innovative structural reforms designed to do...away with the old elitist and corrupt way of implementing socioeconomic policies. One of these reforms, the Industrial Community, was to result in

  6. Ontological Issues in Higher Levels of Information Fusion: User Refinement of the Fusion Process

    DTIC Science & Technology

    2003-01-01

    fusion question, the thing that is separates the Greek We explore the higher-level purpose offusion systems by philosophical questions and modem day...the The Greeks focused on both data fusion and the Fusion02 conference there are common fusion questions philosophical questions of an ontology - the...data World of Visible Things Belief (pistis) fusion - user refinement. The rest of the paper is as Appearances follows: Section 2 details the Greek

  7. The Prussian Reform Movement: A Case Study in Defense Reform

    DTIC Science & Technology

    1989-09-01

    H ., ed., The German Mind of the 19th Century , Continuum, 1981. Goerlitz, W., History of the German General Staff...set by technology and by the political and social conditions of Prussia in the eighteenth century ."E" ’Frederick H , Miariches Testament von 1768, pp... History of Germany Since 1789. pp. 34-35, Frederick A. Praeger, 1968. "𔃽Holbom, H ., A History of Modem Germany 1648-1840, p. 393, Yale Univ. Press,

  8. Like No. 1 Mike Leavitt, most atop the 100 Most Powerful wield their influence from D.C., and help determine how money is spent.

    PubMed

    Romano, Michael

    2005-08-22

    Modem Healthcare's fourth annual ranking of the 100 Most Powerful People in Healthcare boasts an eclectic group. Those who practice medicine and teach it to others share the list with presidents of companies and the president of the country. Lawmakers and information technology risk-takers round out a roster that mirrors the industry's diversity and highlights the many ways people contribute to healthcare.

  9. A Research Study to Develop an Army-Wide Equal Opportunity Training Model. Volume 1

    DTIC Science & Technology

    1979-03-01

    three areas is detailed below. Personal Discrimination Personal racism (or sexism ) is defined in AR 600-21 in terms of " The acting out of prejudices by...example (6) Diagnosing unit climate on racism / sexism issues (a) unit survey (b) informal feedback (c) personal observation (7) Developing...various communities out of which the modem serviceman emerges. • Group Leadership Practicum-to provide the student with the theory and practice in

  10. Phase I Historic Resources Survey Lowndes Wildlife Management Area Lowndes County, Alabama.

    DTIC Science & Technology

    1998-01-01

    years ago. Terrace E has the same general longitudinal profile and gradient as the modem river channel and has an approximate elevation range of between...to new. Shifts in dominant forest species occurred and large mammals ( megafauna ) such as the mammoth and archaic bison began moderate population...the human population was small during this time, it is likely that their hunting of the large animals ( megafauna ) hastened their extinction. From 3,000

  11. Microwave Tube Reliability

    DTIC Science & Technology

    1976-06-01

    t’ibes discussed demonstrate a 2000-hour life in the laboratory but exhibit only a 200- hour i’fc in systems. The tubes reported on were broadband , helix ...control. Two such critical operations are helix winding and pyrolytic deposition. The ,slow-wave structureof .he modem TWT -is rarely a simple uniform...Il No customer complaint (2) 1I Open helix (1) 1 High harmonics, low power<l) The group A and B -symptoms indicated by the failure report data weL

  12. The Development of the Command and Control Centre for Trial Kondari

    DTIC Science & Technology

    2010-07-01

    the C2 centre inside a blue bubble whose modems have privately assigned IP addresses which are authenticated by Telstra’s radius server. No other sim...cards can communicate on this private network unless authorised by the radius server. The Next IP network is a network bubble within the larger Next...for all machines on the network.  EPLRS Network Manager (ENM) radio – authenticates and manages all the EPLRS radios. The basic plan’s final

  13. International Halley Watch: Discipline specialists for spectroscopy and spectrophotometry

    NASA Technical Reports Server (NTRS)

    Wyckoff, S.; Feston, M. C.; Wehinger, P.

    1986-01-01

    Spectroscopic observations of Comets P/Crommelin, P/Giacobini-Zinner and P/Halley are coordinated, preliminary results are delivered to the astronomical community and the data collected from observers throughout the world are archived. The ASU IHW Center has the additional responsibility of maintaining the IHW Electronic Bulletin Board which reports real-time information on the status of Comet P/Halley. Access to this electronic bulletin board via telephone modem connection is available to any astronomer upon request.

  14. Novel Magnetic Devices

    DTIC Science & Technology

    2007-10-12

    Vincent, Magnetism Magnetic Materials (LAW3MO5), Vifia del Mar, Chile, December 11-15, 2005. 5. Nanomagnetism, Ivan K. Schuller, Pan America Advanced Study Institute, PASI 2007, Zacatecas , Mexico , June 19, 2007. 6 ...project explored the design, preparation, measurement and theoretical study of these novel magnetic devices. Modem thin film techniques (sputtering and...results to motion associated with the unstable nature of mechanical contacts In order to exploit BMR from a device point of view (or to make it useful in a

  15. Advanced Modulation and Coding Technology Conference

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The objectives, approach, and status of all current LeRC-sponsored industry contracts and university grants are presented. The following topics are covered: (1) the LeRC Space Communications Program, and Advanced Modulation and Coding Projects; (2) the status of four contracts for development of proof-of-concept modems; (3) modulation and coding work done under three university grants, two small business innovation research contracts, and two demonstration model hardware development contracts; and (4) technology needs and opportunities for future missions.

  16. Department of the Navy Justification of Estimates for Fiscal Year 1987 Submitted to Congress February 1986. Operation & Maintenance, Navy. Book 2. Budget Activity 7: Central Supply and Maintenance.

    DTIC Science & Technology

    1986-02-01

    supported and trained. 242 294 250 .W - Telecommunications lines/ modems / multiplexes/controller 55 62 55 ,. .. CPU/time-sharing usage cycles (MIL) 132 160...46K BBLS 56K BBLS 56K B. Ship Energy 100 82 65 Conservation Savinqs 19K P.BLS 19 K BBLS 19K BBLS *BBLS = Barrels of oil saved n. SHIP SYSTEMS 1. Ship

  17. Voxel-based Immersive Environments Immersive Environments

    DTIC Science & Technology

    2000-05-31

    3D accelerated hardware. While this method lends itself well to modem hardware, the quality of the resulting images was low due to the coarse sampling...pipes. We will use MPEG video compression when sending video over T1 line, whereas for 56K bit Internet connection, we can use one of the more...sent over the communication line. The ultimate goal is to send the immersive environment over the 56K bps Internet. Since we need to send audio and

  18. Continental paleothermometry and seasonality using the isotopic composition of aragonitic otoliths of freshwater fishes

    NASA Astrophysics Data System (ADS)

    Patterson, William P.; Smith, Gerald R.; Lohmann, Kyger C.

    To investigate the applicability of oxygen isotope themometry using fish aragonite, the δ18O values of paired otolith and water samples were analyzed from six large modem temperate lakes. Otoliths are accretionaiy aragonitic structures which are precipitated within the sacculus of fish ears. Deep-water obligate benthic species from the hypolimnion of the Laurentian Great Lakes of North America and Lake Baikal, Siberia, provided cold-water end member values for aragonite δ18O. Warm-water values were obtained from naturally grown warm-water stenothermic species and from fish grown in aquaria under controlled conditions. These two groups, which represent growth over a temperature range of 3.2-30.3°C. were employed to determine the oxygen isotope temperature fractionation relationship for aragonite-water: 103lnα = 18.56 (±0.319)·(103)T-1 K -33.49 (±0.307). Empirical calibration of a fish aragonite thennometry equation allows its direct application to studies of paleoclimate. For example, high-resolution sampling of shallow-water eurythermic species coupled with a knowledge of the isotopic composition of meteoric waters can be used to determine seasonal temperature variation. This approach was tested using a modem shallow-water eurythermic species from Sandusky Bay, Lake Erie. Temperatures calculated from carbonate composition agree with meteorological records from the Sandusky Bay weather station for the same time period.

  19. [Nature as magician: on the Paracelsus heritage of modern medicine].

    PubMed

    Heinz, Schott

    2010-01-01

    The concept of "natural magic" (magia naturalis) was very important for medicine and natural science of the early modem period. It stressed a new scientific world view (Weltanschauung) moving away from "supernatural" (superstitious) perceptions and trying to explain all spectacular marvels as results of natural processes. So, Nature (natura), often personified as a female figure, was considered as a (female) magician. Physicians and naturalists should learn from her art to become able to imitate and accomplish her work. In particular this concept was relevant for the al-chemical and magical medicine as the writings of PARACELSUS show. He perceived like many of his contemporaries Nature as a servant of God producing all things according to his will supplying them with "signatures" indicating the scholar (philosophus) their hidden ("natural") powers. The iconography and emblematics of the early modem period--partly directly influenced by the paracelsian thinking--illustrate in different ways the concept of natural magic. Especially the hierarchy God--Nature--Human and the phenomena of light representing divine wisdom and power were imagined. It is remarkable, that also during the enlightenment in regard to artificial electricity and animal magnetism analogous ideas appeared in connection with the light imagery (ether, fluidum). Finally, the romantic natural philosophy dealt with them intensively, and they stimulated not only natural scientific respectively (neuro) physiological, but also psychological (experimental) research.

  20. Abrupt Climate Change in the Atlantic Ocean During the Last 20,000 Years: Insights from Multi-Element Analyses of Benthic and Planktic Foraminifera and a Coupled OA-GCM

    DTIC Science & Technology

    2005-09-01

    paleoceanographic and terrestrial climate proxies . Greenland ice cores, in particular, provide evidence of large amplitude, very rapid climate change during...received the most attention because it is the largest Holocene excursion in the GISP2 810 record [Alley et al., 1997]. Multiple proxies in Greenland ice...latitude North Atlantic foraminiferal-based proxies such as modem analogue technique [Marchal et al., 2002; Risebrobakken et al., 2003], but

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