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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
381

TELEMETERING SYSTEM FOR THE UA SATELLITE

Hammond, C., Beauvarlet, D., Kipple, A., Condit, R., Firestone, T., Ling, V., Morris, G., Powers, D. 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / This student paper was produced as part of the team design competition in the University of Arizona course ECE 485, Radiowaves and Telemetry. It presents a telemetering system proposed for UASat, a small satellite being designed for launch in the year 2004. The overall system architecture is described, including the transducers used by each subsystem, the command and telemetry packet formats, the antennas and modulation schemes, the link budget, and some hardware recommendations. A discussion of the data analysis is also included.
382

COMMERCIAL-OFF-THE-SHELF TELEMETRY FRONT-END PROTOTYPING

Hogie, Keith, Weekley, Jim, Jacobsohn, Jeremy 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The world of data communication and networking has grown rapidly over the last decade, and this growth has been accompanied by the development of standards that reflect and facilitate the need for commercial products that work together in a reliable, robust, and coherent fashion. To a great extent this commercialization, with its increasing performance and diminishing cost, has not been adapted to the data communication needs of satellites. As budgets and mission development and deployment timelines shrink, space exploration and science will require the development of standards and the use of increasing amounts of off-the-shelf hardware and software for integrated satellite ground systems. The Renaissance project at NASA/Goddard Space Flight Center has engaged in rapid prototyping of ground systems using off-the-shelf hardware and software products to identify ways of implementing satellite ground systems "faster, better, cheaper". This paper presents various aspects of these activities, including issues related to the configuration and integration of current off-the-shelf products using telemetry databases for existing spacecraft, an analysis of issues related to the development of standard products for satellite communication, tradeoffs between hardware and software approaches to performing telemetry front-end processing functions, and proposals for future standards and development.
383

THE CHALLENGES OF LOW-COST, AUTOMATED SATELLITE OPERATIONS

Farmer, Mike, Culver, Randy 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Satellite operations have been inherently manpower intensive since they began over thirty years ago. Since manpower intensive equates to costs, this mode of operations cannot survive in light of government budget cuts and commercial profitability. Two factors are now key for both government and commercial satellite control centers: 1) systems must be highly automated to minimize the operations staff, and 2) these automated systems must be deployed and enhanced at a low cost. This paper describes the three principle challenges which arise in migrating from high-cost, manpower intensive satellite operations to low-cost, automated satellite operations and makes recommendations for solving them.
384

Using Commercial Global Personal Communication System for a Global Test Range

Rogers, Rodney, LeBlanc, James P., Ryerson, David E., Snell, James 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper investigates the feasibility of using commercial satellite constellations to relay telemetry data from flight test vehicles as part of a Global Test Range. The use of a commercial satellite constellation would provide an augmented capability to the test range, providing near real-time data to the data reduction site and test range control at reasonable cost. This includes an analysis of current and proposed commercial communication satellite constellations to determine if any of them would fulfill the needs of a telemetry test range. Preliminary assessment of the communication link between a flight vehicle and the satellite constellations is performed.
385

NETWORKING SATELLITE GROUND STATIONS USING LABVIEW

Mauldin, Kendall 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / A multi-platform network design that is automated, bi-directional, capable of store and forward operations, and low-bandwidth has been developed to connect multiple satellite ground stations together in real-time. The LabVIEW programming language has been used to develop both the server and client aspects of this network. Future plans for this project include implementing a fully operational ground network using the described concepts, and using this network for real-time satellite operations. This paper describes the design requirements, RF and ground-based network configuration, software implementation, and operational testing of the ground network.
386

A NEW SATELLITE COMMUNICATION ANTENNA FOR AEGIS CLASS DESTROYERS

Gonzalez, Daniel G., Richard, Gaetan C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The requirement for a lightweight, quick deployment C-Band satellite communication antenna system for Aegis Class Destroyers has been addressed and this paper describes a novel solution currently being implemented. The new antenna system takes advantage of the low windload properties of the FLAPS™ (Flat Parabolic Surface) reflector and features a broadband FLAPS™ reflector mounted on a lightweight, high performance X-Y positioner. The system is designed in a modular fashion and operates in a shipboard environment without the protection of a radome. The system is stabilized to counteract the ship's motion, operates without counterweights, weighs less than 250 kg and provide communication links in the 3900 to 4100 MHz and 6000 to 6200 MHz frequency bands.
387

AUTONOMOUS ACQUISITION OF ENVIRONMENTAL DATA IN A GLOBAL NETWORK ENVIRONMENT

Grubinger, Michael, Strohmeier, Felix 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the results of a feasibility study undertaken by the University of Salzburg (Austria), investigating the autonomous acquisition of environmental data in a global network. A suggested application which is used as the basis of this paper is a volcano monitoring system which would be able to track the activity of a volcano and act as a disaster warning system. The background Volcano observation data required for such a system is covered, before discussing the concepts for sensor data acquisition, storage and processing. A final analysis is then presented of the opportunities for the transmission by packet radio (both terrestrial and satellite).
388

THE SPACE IMAGING OPERATIONS CENTER

Clemons, Robert R. 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The next-generation commercial imaging satellites will generate data at several times the rate of current systems. To be commercially successful, these systems must have earth stations as sophisticated as the satellites themselves. Space Imaging has worked with E-Systems to exploit technologies developed over four generations of image processing, analysis and application systems to create a modular, standards-based, earth station for commercial use. A Space Imaging Operations Center can be configured in a variety of ways to provide complete, end-to-end, capabilities, from task generation to receipt of downlink, image processing, and product generation. While it is intended primarily for use with imagery from Space Imaging and other commercial satellites, an Operations Center can also accept, process and manage data from land-based, airborne or seaborne collectors. A sophisticated data management product, Mission Server™, handles and routes all data from signal receipt through final product generation. A unique family of data processing applications permit simultaneous manipulation and analysis of integrated map, image, graphic and text data. Online data storage and archiving are provided by the EMASS® family of products. An Operations Center of any size can accept, process and manage data streams of several hundred megabits per second in real time.
389

INCA Cubesat: A Design Analysis of the Telemetering System

Burgett, Taylor 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The goal of this project is maximize the performance of the telemetering system for the INCA cubesat mission using what we are learning in class to develop tests to figure out the optimal selection of frame scheme, data rate, and modulation technique based on the requirements of the mission. This project will help me learn about different modulation techniques and give me real world experience testing a telemetry system. I will evaluate my results through a comparison of the error rates for the different modulation schemes and do statistical analysis to show the reliability of the data. The results will be useful to any future mission that implements the same satellite communication system including future missions at NMSU.
390

Improved description of Earth's external magnetic fields and their source regions using satellite data

Shore, Robert Michael January 2013 (has links)
In near-Earth space, highly spatio-temporally variant magnetic fields result from solar-terrestrial magnetic interaction. These near-Earth external fields currently represent the largest source of error in efforts to model the magnetic field produced in the Earth’s interior. Starting in 1999, the Decade of Geopotential Field Research (Friis-Christensen et al., 2009) has greatly increased the amount of available low-Earth orbit (LEO) satellite magnetic data. These data have driven many advances in field modelling, yet have highlighted that LEO measurements are particularly susceptible to contamination from external fields. This thesis presents a series of studies attempting to describe the external fields in more detail, in order that they can be more effectively separated from the internal fields in magnetic modelling efforts. A range of analysis methods, different for each study, are applied to satellite and ground-based observatory data. Mandea and Olsen’s (2006) method of estimating the secular variation (SV) of the internal field from satellite data via ‘Virtual Observatories’ (VOs) is applied to synthetic data from the upcoming Swarm constellation satellite mission of the European Space Agency. Beggan (2009) found VOs constructed from CHAMP satellite data to be contaminated with external field signals which appeared to have a significant local time (LT) dependence. I find that utilising the increased coverage of LT sectors offered by the Swarm constellation geometry does not significantly decrease the contamination. Following this surprising result I tested a wide range of methods aimed at reducing the VO contamination from each parameterised external field source region. In anticipation of future studies using real data, I used the results of the tests to provide a more complete description of the external field variations affecting analyses of geographically-fixed magnetic phenomena when using satellite data and spherical harmonic analysis (SHA). Ionospheric electric currents flowing at LEO altitudes are known to violate the assumption of measurements taken in a source-free space, required in SHA-based models of the magnetic field. In order to better describe the electromagnetic environment at LEO altitudes, I use data from the Ørsted and CHAMP satellites to calculate the current density from Amp`ere’s integral. Vector magnetic data from discrete overflights of the two satellites (at different altitudes) are rotated into the along-track frame to define the integral loop and its ‘surface area’, permitting estimation of the predominantly zonal current density flowing in the region between the two orbital paths. I designed selection criteria to extract geometrically-stable overflights spanning the range of LTs twice in the 6 years of mutually available satellite vector data. From these overflights I resolve current densities in the range 0:1 μA=m2, with the distribution of current largely matching the LT progression of the Appleton anomaly. I applied detailed tests to check for biases intrinsic to the method, and present results free of systematic errors. The results are compared with the predictions of the CTIP (Coupled Thermosphere-Ionosphere-Plasmasphere) model of ionospheric composition and temperature, showing a typically good spatiotemporal agreement. I find persistent current intensifications between geomagnetic latitudes of 30 and 50 in the post-midnight, pre-dawn sector, a region which has been previously considered to be relatively free of currents. External fields induce currents in the Earth’s conducting mantle, the magnetic fields of which add to the field measured at and above the Earth’s surface. The morphology of the long-period inducing field is poorly resolved on timescales of months to years, reducing the accuracy of mantle induction studies (a key part of the Swarm mission). I improve the description of its morphology via the method of Empirical Orthogonal Functions (EOFs), which I apply to over a decade of ground-based observatory data. EOFs provide a decomposition of the spatiotemporal structures contained in the magnetic field data, with partitions arising from the data themselves, overcoming the relatively simplistic assumptions made about the inducing field morphology in LT. The results of vector data EOF analyses are presented, but I rely primarily on scalar analyses which are more fitting for this study. I overcome the limitations of the irregular observatory distribution with a novel spatial weighting matrix, combining the output from multiple EOF analyses to greatly improve the data coverage in LT. I find that the seasonal variation of the inducing field is more important than the variation of the symmetric ring current on annual periods, and that dawn-dusk asymmetry should be accounted for to increase the accuracy of mantle conductivity estimates based on data covering the decadal timescales of the solar cycle.

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