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1
Brengesjö, Carl, and Martine Selin. "Tracking System : Suaineadh satellite experiment." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-52906.
Testo completoAbstract (sommario):
The purpose of this bachelor thesis is to present a tracking system for the Suaineadh satellite experiment. The experiment is a part of the REXUS (Rocket EXperiments for University Students) program and the objective is to deploy a foldable web in space. The assignment of this thesis is to develop a tracking system to find the parts from the Suaineadh experiment that will land on Earth. It is important to find the parts and recover all the data that the experiment performed during the travel in space. The implementation of this thesis investigates two different ways to track and find the experiment. The first way is to locate the experiment module by a Global Positioning System (GPS) and send the coordinates to a satellite modem, controlled by a programmed microprocessor. The other way is by using a radio beacon that sends a speciffic radio frequency. The results of this thesis presents a prototype for the tracking system with a GPS and the satellite modem and code example for the microprocessor. It also presents a working radio freqency beacon system on a Printed Circuit Board. The thesis had some unexpected incidents and had to change some directives. This rendered the work to take longer time then estimated. Despite the difficulties resulted this thesis in a working system to track the experiment.
2
Edwards, David J. "Tracking systems for satellite communications." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379579.
Testo completo
3
Anderson, Mike, Peter Militch, and Hugh Pickens. "AN AUTONOMOUS SATELLITE TRACKING STATION." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/607307.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>In 1998, AlliedSignal Technical Services (ATSC) installed three fully autonomous 13-meter satellite tracking systems for the Integrated Program Office of the National Oceanic
and Atmospheric Administration (NOAA) at the Command and Data Acquisition Station
near Fairbanks, Alaska. These systems track and command NOAA Polar Orbiting Weather
Satellites and Defense Meteorological Satellites.
Each tracking system operates for extended periods of time with little intervention other
than periodic scheduling contacts. Schedule execution initiates equipment configuration,
including establishing the RF communications link to the satellite. Station autonomy is
achieved through use of a robust scheduler that permits remote users and the System Administrator
to request pass activities for any of the supported missions. Spacecraft in the
mission set are scheduled for normal operations according to the priority they have been
assigned. Once the scheduler resolves conflicts, it builds a human-readable control script
that executes all required support activities. Pass adds or deletes generate new schedule
scripts and can be performed in seconds.
The systems can be configured to support CCSDS and TDM telemetry processing, but the
units installed at Fairbanks required only telemetry and command through-put capabilities.
Received telemetry data is buffered on disk-storage for immediate, post-pass playback,
and also on tape for long-term archiving purposes. The system can autonomously support
up to 20 spacecraft with 5 different configuration setups each. L-Band, S-Band and X-Band
frequencies are supported.
4
Sharifi, Mohammad A. "Satellite to satellite tracking in the space-wise approach." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-28337.
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5
Han, Shin-Chan. "Efficient global gravity field determination from satellite-to-satellite tracking." Columbus, Ohio : Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1061995200.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Ohio State University, 2003.<br>Title from first page of PDF file. Document formatted into pages; contains xvii, 198 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Christopher Jekeli, Dept. of Geodetic Science and Surveying. Includes bibliographical references (p. 192-198).
6
Kenington, P. B. "Tracking receiver design for the electronic 'beam squint' tracking system." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235772.
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7
Hansen, Jeremy Roger. "Wide field of view satellite tracking." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0031/MQ65844.pdf.
Testo completo
8
Glim, Carl. "MULTI-USER SATELLITE TRACKING NETWORK SCHEDULING." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/609211.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>The recent proliferation of Low Earth Orbiting (LEO) science, earth resources, and global communication satellites requires a significant number of ground stations for support. A network of satellite tracking ground stations with the ability to support multiple users and communicate with multiple satellites requires a robust scheduling and conflict resolution system. This paper describes an automated scheduling implementation for managing such a commercial, multi-user, multiple satellite, ground station network.
9
Hansen, Jeremy Roger. "Wide field of view satellite tracking." Ottawa : National Library of Canada = Bibliothèque nationale du Canada, 2002. http://www.nlc-bnc.ca/obj/s4/f2/dsk1/tape3/PQDD%5F0031/MQ65844.pdf.
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10
Kim, Jeongrae. "Simulation study of a low-low satellite-to-satellite tracking mission /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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11
Ramírez, Eduardo Díaz. "A MORE EFFICIENT TRACKING SYSTEM FOR THE SANTIAGO SATELLITE TRACKING STATION." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604559.
Testo completoAbstract (sommario):
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada<br>A digital antenna control system has been designed and installed on a pedestal that was formerly
used to drive a VHF array and that has now been replaced with an 11 meter S-Band parabolic
reflector.
In this Paper, the former analog tracking system will be described, showing all the drawbacks
that made it unusable for S-Band. Subsequently, the development and implementation of the
digital S-Band tracking system, using Labview, C++ & digital control theory will be discussed.
Finally, there will be a comparison between the digital and analog system, too.
12
Jawad, Ali J. "An optimised antenna controller for satellite tracking." Thesis, University of Dundee, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243825.
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13
Dedes, George C. "Baseline estimation from simultaneous satellite laser tracking /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487331541708489.
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14
Elster, Jennifer Leith. "Quantification and Tracking of Transplanted Satellite Cells." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195718.
Testo completoAbstract (sommario):
Satellite cells are adult stem cells that contribute to hypertrophy and repair in muscles. It is hypothesized that in muscular dystrophy, the satellite cells population is depleted at a very early age, due to repeated muscle damage and repair. Satellite cell transplantation is a potentially useful therapy for muscle diseases, but the lack of an efficient delivery system has hindered its application. The presented work focuses on two specific aims that address the need for more effective cell delivery methods for cell-based therapy. In Specific Aim 1 enhanced tissue culture techniques, such as heat stress, are used to increase cell survival in satellite cell transplantation studies. Also addressed within this specific aim are methods to label and evaluate performance using real-time PCR techniques.Although much work remains to enhancing the viability of in vitro expanded myoblasts derived from satellite cells, a second important hurdle is the systemic delivery of satellite cells to multiple sites (all muscles, in the case of muscular dystrophies). In vitro and in vivo experiments are being undertaken to explore the physiological role of cell signaling systems involved in directed migration and to determine if these chemokine and growth factors can be manipulated to enhance efficacy of cell-based therapies involving skeletal muscle satellite cells. Specific Aim 2 addresses migration of satellite cells to sites of injury and methods to track transplanted cells within the host. Presented here is the use of FAST SPECT II imaging of 111-Indium oxine radiolabeled satellite cells. The long lifetime of 111-indium oxine and the ability to quantify label using FAST SPECT imaging techniques make this technique ideal for in-vivo tracking of transplanted satellite cells for week long studies. Without in-vivo imaging techniques cell fate studies require sequential animal sacrifice with histological sectioning. This not only increases the number of animals used but also adds a significant inter-animal variability to their assessment. The determination of cell fate after transplantation will have a major impact on cell therapy for treatment of muscle disease as well as other stem cell therapies.
15
Chen, Yiqun. "Recovery of terrestrial water storage change from low-low satellite-to-satellite tracking." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196098152.
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16
Nasta, Rodolphe. "TELECOMMUNICATION SATELLITE TELEMETRY TRACKING AND COMMAND SUB-SYSTEM." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607355.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>This paper gives an overview on Telemetry, Tracking and Command (TTC) sub-system
that are used onboard some telecommunication satellites. Then, a description of the
equipments of such a sub-system is given, together with the main performances.
17
French, John. "Satellite technology for tracking birds and sea mammals." Thesis, University of Aberdeen, 1986. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU362526.
Testo completoAbstract (sommario):
Burgeoning world communication networks indicate a period of intense investment in space technology, this makes it a good point in time to pose the question: Is there a satellite location system capable of remotely recording the track of an electronics package made small enough for a bird to carry? Clearly a solution for birds will considerably advance the possibility of tracking other wildlife and indeed almost any artefact. The laws of nature give a finite working lifetime to all earth satellites. This and the steady advance of technology means that satellite systems are deployed and fade from use over a single decade. While replacements for those that malfunction or become exhausted can be launched, improved concepts consistently make periodic system replacement more worthwhile. Among the currently available satellite systems capable of positioning, the Argos data collection and location system is the most suitable for wildlife tracking. A short explanation of Doppler positioning is given and examples of data from remote sensing satellites show some of the background data available. I have briefly cited early studies on Elk, Polar bears, Dolphins, Turtles, Basking shark and Humpback whales. Design work for the bird location package begins in section 3. An experimental harness is tested together with a lightweight pure nickel case for the electronic assembly. Environment effects are considered and wind tunnel tests are made to determine drag and heat loss. Sub-sections 3-1 to 3- 8 complete the work as follows:- High stability oscillator. A circuit with acceptable performance and minimal power input is evolved by investigation of each component. RF power circuits and phase modulator designed for minimal part count are described. Digital encoder, required to generate the PTT identity code etc is described, it uses microminiature components and a CMOS field programmable ROM. A developed version for sensor data input is also described. Antenna, this is designed using a model bird filled with a fluid having similar permittivity and conductivity to living tissue. Impedance and field patterns are measured using a signal source, vector voltmeter, reflectometer, spectrum analyser and specialised test equipment. Power is derived from lithium cells as a result of pulse testing to identify the best type; solar arrays are also investigated. Possible behavioural aberrations due to RF emissions are considered as the RF pulse power is 30 dBs (1000 times) higher than conventional equipment at VHF. It is shown that avian heart-rate is not affected by the RF pulse. Results and conclusions Solutions to engineering problems encountered in applying the design to birds, seals and whales are shown to be successful by the results of field trials. Appendices outline supporting work.
18
Zaheer, Muhammad. "Kinematic orbit determination of low Earth orbiting satellites, using satellite-to-satellite tracking data and comparison of results with different propagators." Thesis, KTH, Geodesi och geoinformatik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142627.
Testo completoAbstract (sommario):
The GPS data from Challenging Mini-satellite Payload (CHAMP) is used for its orbit determination for the epoch day of January 1st 2002. The orbit of CHAMP is computed from the GPS data and ionospheric effects are removed by frequency combination. Further, the orbits of CHAMP for the same epoch day are computed using the satellite tool kit (STK) employing simplified general perturbations (SGP4) and a high precision orbit propagator (HPOP). Results from both techniques (GPS computed orbit and STK computed orbit) are compared. Furthermore, orbits computed using GPS data are also compared with jet propulsion laboratory’s published CHAMP spacecraft orbit and we have found that root mean square difference in ECEF position X component is below 0.01km other than some spikes at poles. The standard deviation of the difference in ECEF position X coordinate is 11.7m. The accuracy of our computed satellite positions (using GPS data) is about 12 metres for other than polar areas. However there are some occasional spikes, especially at poles, having maximum errors (about 0.055 km).
19
Liu, Xianglin. "Global gravity field recovery from satellite-to-satellite tracking data with the acceleration approach /." Delft : NCG Nederlandse Commissie voor Geodesie, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=9789061323096.
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20
Luciani, Daniel Patrick. "System Design and Implementation of the Virginia Tech Optical Satellite Tracking Telescope." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71387.
Testo completoAbstract (sommario):
The Virginia Tech Optical Satellite Tracking Telescope (VTOST) aims to test the feasibility of a commercial off-the-shelf (COTS) designed tracking system for Space Situational Awareness (SSA) data contribution. A novel approach is considered, combining two COTS systems, a high-powered telescope, built for astronomy purposes, and a larger field of view (FOV) camera. Using only publicly available two-line element sets (TLEs), orbital propagation accuracy degrades quickly with time from epoch and is often not accurate enough to task a high-powered, small FOV telescope. Under this experimental approach, the larger FOV camera is used to acquire and track the resident space object (RSO) and provide a real-time pointing update to allow the high-powered telescope to track the RSO and provide possible resolved imagery. VTOST is designed as a remotely taskable sensor, based on current network architecture, capable of serving as a platform for further SSA studies, including unresolved and resolved imagery analysis, network tasking, and orbit determination. Initial design considerations are based on the latest Raven class and other COTS based telescope research, including research by the Air Force Research Lab (AFRL), ExoAnalytic Solutions, and other university level telescope projects. A holistic system design, including astronomy, image processing, and tracking methods, in a low-budget environment is considered. Method comparisons and results of the system design process are presented.<br>Master of Science
21
Joodaki, Gholamreza. "Earth Mass Change Tracking Using GRACE Satellite Gravity Data." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bygg, anlegg og transport, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23969.
Testo completoAbstract (sommario):
This project is dealing with the estimation of present-day Earth’s mass transport and its redistribution by using observations from Gravity Recovery and Climate Experiment (GRACE) satellite mission. GRACE measures the gravity fluctuations which are primarily related to redistribution of water around the globe. GRACE data has yield profound new insights into melting rates of ice sheets and mountain glaciers, land hydrology, ocean circulation, and sea level rise. In this project, first, the ice melting rate in the Greenlandic ice sheet is studied. This is done by analyzing the time series of monthly GRACE release 04 gravity field solutions from three different data sets, CSR (Center for Space Research), GFZ (Geoforschungszentrum), and JPL (Jet Propulsion Laboratory) with respect to their long-term temporal changes. The data are de-striped by applying a non-isotropic filter. Also, a method for reducing the leakage effects is developed. As an example, the ice mass balance is estimated of -163 ± 20 Gt/yr based on the CSR release 04 and smoothing by a parameter of a =1013 during April 2002 to February 2010. The results also show that the spatial distribution of the ice mass loss is changing with time and the ice mass loss is accelerating. For example, its acceleration is a rate of -32±6 Gt/yr2 during 2002 to 2011. The second part of this project is concern with the determination of water mass changes in the Nordic Seas. It is determined by analyzing the time series of monthly GRACE level 2 release 04 data from GFZ during October 2002 to October 2010. The striping errors are reduced by using a non-isotropic filter and the data are smoothed by a parameter of a =1014 according to Gaussian smoothing radius of 530 km. The time series of water mass changes are used to study the steric sea height variations over the Nordic Seas during the same period of study. This is done by analyzing the time series of monthly sea level anomaly from ENVISAT (Environmental Satellite) altimetry data, cycles 10 to 93, among the time series of water mass changes. The results show that the interdisciplinary nature of the GRACE measurements have opened up the unique opportunity to enhance our knowledge on the interaction between Earth system components and their response to climate variability. In the last part of this project, variations of the continental total water storage, total groundwater storage, and anthropogenic contributions across the Middle East are studied. By using a mascon analysis method and GRACE level 2 release 05 data from CSR during February 2003 to December 2012, the time series of total water storage, total ground water storage and anthropogenic contributions are estimated over this region. The region is subdivided to seven mascons including Iran, Iraq, Syria, eastern Turkey (east of 35º longitude), northern and southern Saudi Arabia (north and south of 25º latitude), and the region immediately west of Caspian Sea. The total groundwater storage, and anthropogenic contributions are separated from the total water storage by using the CLM4.5 (version 4.5 of the Community Land Model) hydrological model. The results show that Iran with a rate of 25±6 Gt/yr has the most groundwater loss rate during February 2003 to December 2012 in this region. The Iran’s rate of groundwater loss from the GRACE data is supported by an analysis of in situ well data from across Iran. The results also show that the GRACE mission is able to monitor monthly water storage changes within river basins and aquifers that are 200,000 km2 or larger in area, and, can contribute to water management at regional and national scales, and to international policy discussions as well.<br><p> </p><p> </p><p> </p>
22
Barker, Drew R. (Drew Richard) 1981. "Robust randomized trajectory planning for satellite attitude tracking control." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36173.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.<br>Includes bibliographical references (p. 121-125).<br>This thesis presents a novel guidance strategy that uses a randomized trajectory planning algorithm in a closed-loop fashion to provide robust motion planning and execution. By closing the guidance, navigation, and control loop around a randomized trajectory planning algorithm, a robotic vehicle can autonomously maneuver through a field of moving obstacles in a robust manner. The guidance strategy provides executable plans that are robust to known error sources when supplied with an estimate of the initial state, the goal, the predicted locations of obstacles, and bounds on error sources affecting the execution of a planned trajectory. The planning function presented in this thesis extends the Rapidly-exploring Random Tree algorithm to dynamic environments by exploring the configuration- x-time space using a node selection metric based on the maneuvering capability of the vehicle. The guidance strategy and the new randomized trajectory planning algorithm are applied to a challenging satellite attitude guidance problem in simulation.<br>by Drew Richard Barker.<br>S.M.
23
Busch, Chuck E. "Servo Controls for Low S/N Satellite Auto-Tracking." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581627.
Testo completoAbstract (sommario):
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California<br>At very low Signal to Noise receive ratios, a typical Autotrack servo loop exhibits significant servo noise tracking jitter that can degrade the received signal characteristics. The angular jitter can be minimized by a lowering of the autotracking servo loop bandwidth, but at the sacrifice of the servos ability to reject external torque disturbances, such as wind deflections. As satellite downlinks continue to move to higher frequencies, the angular errors caused by either the tracking noise or the wind deflections of a receive antenna will have increasingly negative effect on the quality of the received data. This paper examines the performance of a servo algorithm that maintains the needed wide bandwidth characteristics of wind deflection rejection while achieving the noise smoothing characteristics of a very low bandwidth Autotrack servo response. The control algorithms have been tested on a 13 meter Remote Sensing Satellite tracking system to determine the overall tracking performance of the new implementation. Current results indicate that the new servo configuration achieves the desired results typical of a wide bandwidth system of high wind rejection and low target dynamics tracking errors. At the same time, it provides elimination of slowly changing errors from axis miss-alignments, thermal effects, and gravitational effects and the low RF noise jitter performance typical of a low bandwidth system.
24
Wang, Yue-Jin. "Adaptive data processing satellite positioning." Thesis, Queensland University of Technology, 1994.
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25
Lau, King Shing Albert. "Application of image analysis techniques to satellite cloud motion tracking." Thesis, University of Plymouth, 1992. http://hdl.handle.net/10026.1/1131.
Testo completoAbstract (sommario):
Cloud motion wind (CMW) determination requires tracking of individual cloud targets. This is achieved by first clustering and then tracking each cloud cluster. Ideally, different cloud clusters correspond to diiferent pressure levels. Two new clustering techniques have been developed for the identification of cloud types in multi-spectral satellite imagery. The first technique is the Global-Local clustering algorithm. It is a cascade of a histogram clustering algorithm and a dynamic clustering algorithm. The histogram clustering algorithm divides the multi-spectral histogram into'non-overlapped regions, and these regions are used to initialise the dynamic clustering algorithm. The dynamic clustering algorithm assumes clusters have a Gaussian distributed probability density function with diiferent population size and variance. The second technique uses graph theory to exploit the spatial information which is often ignored in per-pixel clustering. The algorithm is in two stages: spatial clustering and spectral clustering. The first stage extracts homogeneous objects in the image using a family of algorithms based on stepwise optimization. This family of algorithms can be further divided into two approaches: Top-down and Bottom-up. The second stage groups similar segments into clusters using a statistical hypothesis test on their similarities. The clusters generated are less noisy along class boundaries and are in hierarchical order. A criterion based on mutual information is derived to monitor the spatial clustering process and to suggest an optimal number of segments. An automated cloud motion tracking program has been developed. Three images (each separated by 30 minutes) are used to track cloud motion and the middle image is clustered using Global-Local clustering prior to tracking. Compared with traditional methods based on raw images, it is found that separation of cloud types before cloud tracking can reduce the ambiguity due to multi-layers of cloud moving at different speeds and direction. Three matching techniques are used and their reliability compared. Target sizes ranging from 4 x 4 to 32 x 32 are tested and their errors compared. The optimum target size for first generation METEOSAT images has also been found.
26
Kouris, Aristodimos. "An incoherent correlator-based star tracking system for satellite navigation." Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271771.
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Taunton-Clark, John. "The identification and tracking of Agulhas rings using satellite altimetry." Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/21515.
Testo completoAbstract (sommario):
Includes bibliographical references.<br>The methods of analysing, interpreting and computing surf ace geostrophic currents from GEOSAT altimeter data are explained. These methods were implemented in an examination of GEOSAT altimeter data for the period 12 July 1988 to 13 May 1989 with application to the identification and tracking of Agulhas rings in the southeast Atlantic Ocean. A population of as many circulation features of as five anticyclonic (and cyclonic) annular form consistent with that reported for Agulhas rings was identified from the altimeter data. The positive identification of the same feature in subsequent repeat cycles was, however, difficult. The Verna ring was identified as it travelled approximately along the ground track of GEOSAT pass A 158. Its horizontal (approximately 200 km diameter) and vertical (>30 cm sea surface elevation) dimensions confirmed its identity as an Agulhas ring. The translation speed of the Verna ring along pass A 158 was determined as 6.8 cm·s⁻¹ consistent with the speeds reported in the literature. Surface geostrophic speeds calculated from the altimeter-derived sea surface slopes showed maximum anticyclonic speeds of nearly 40 cm·s⁻¹ toward the SW at the northern rim and 25 cm·s-1 toward the NE at the southern edge of the ring.
28
Stone, Christopher E., Keith D. Flint, and Gregory P. Mathis. "THE PHILLIPS LABORATORY’S MOBILE GROUND TRACKING STATION (MGTS)." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/608411.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada<br>Phillips Laboratory's Space Experiments Directorate (PL/SX) is operating
and upgrading the laboratory's premier transportable satellite tracking
station, the Mobile Ground Tracking Station (MGTS) program. MGTS
supports orbital, suborbital, and aircraft missions as a range system capable
of processing and recording multiple data streams. MGTS receives,
processes, displays, and records satellite state-of-health data, infrared images
in a variety of wavelengths, video data, and state vector solutions based on
IR returns from the Miniature Sensor Technology Integration (MSTI)
satellite program.
The program has began in 1990 under BMDO sponsorship, with the intent to
supplement existing test ranges with more flexibility in range operations.
Wyle Laboratories and Systems Engineering and Management Company
(SEMCO) provided the technical expertise necessary to create the first
MGTS system. Autonomy and off-road capability were critical design
factors, since some of the operations envisioned require deployment to
remote or hostile field locations. Since inception, MGTS has supported the
Lightweight Exo-Atmospheric Projectile (LEAP) sub-orbital missions, the
MSTI satellite program, and Air Force wargame demonstrations. In pursuit
of these missions, MGTS has deployed to White Sands Missile Range
(WSMR), NM; Air Force Flight Test Center (AFFTC), Edwards AFB, CA;
Vandenberg AFB, CA; Falcon AFB, CO; and NASA's Wallops Island Flight
Facility, VA, to receive critical mission telemetry data conforming to both
IRIG and SGLS standards. This paper will describe the evolution of the
MGTS program, current hardware configurations and past and future
mission scenarios for the MGTS team.
29
Hernández-Carrascal, María Angeles. "Motion tracking in meteorological satellite imagery for atmospheric motion vector derivation." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553665.
Testo completoAbstract (sommario):
The focus of this thesis is the tracking of apparent motion from sequences of meteorological satellite images, in the context of Atmospheric Motion Vector (AMV) derivation. AMVs are estimates of atmospheric wind, they are routinely produced from visible, infrared window and water vapour (WV) imagery, and they represent a major contribution to the observation of the Earth's atmosphere. This research tackles a number of issues related to the derivation of AMVs from WV imagery, using region-matching methods for tracking motion. WV imagery is particularly challenging, as images typically have a soft appearance, with no edges, no background, and large areas of low contrast. The datasets used in the experiments are real sequences of images in the WV 6.2 urn band from the geostationary satellite Meteosat-9. The underlying approach throughout the thesis is Gaussian multi-scale representation, a sound mathematical framework, developed by the computer vision community, that allows to analyse images at differente scales and to handle partial derivatives in a way deeply connected to the scale. The main contributions of this thesis are: It shows how Gaussian multi-scale representation can be used with WV meteorological satellite imagery, and in particular its value to handle scales and spatial derivatives. It proposes a new method to detect locations of interest, based on a difference of Gaussians, and shows that it performs better than other detectors, including those commonly used in operational AMV derivation schemes, in the experiments carried out with Meteosat-9 imagery. It proposes a group of distances, based on the Sobolev norm HI, which includes a term to evaluate partial derivatives, to quantify the similarity between neighbourhoods, and it shows that these distances produce better results than the widely used £2 norm, especially when the weight given to the derivatives term is relatively large.
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Wichiencharoen, Chugiat. "Recovery of 1⁰-mean anomalies in a local region from a low-low satellite to satellite tracking mission /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487262825074523.
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Bell, John J. (Jack), James Mileshko, Edward L. Payne, and Paul Wagler. "A MULTIFUNCTION SATELLITE BACKHAUL SYSTEM FOR AIRCRAFT FLIGHT TEST APPLICATIONS." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605336.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California<br>This paper will present the design of a network used to receive and record sensor data and provide voice
communications between a flight controller and the pilot of an aircraft undergoing flight testing in remote
areas. The network utilizes a completely self-contained mobile tracking subsystem to receive and relay
the sensor data and cockpit voice in real-time over a geostationary satellite. In addition to the aircraft
tracking and data/voice relay functions, the system also provides local data recording at the mobile station,
telephone and intercom connectivity between the mobile station and the control center, and remote
equipment setup via the satellite link.
32
Habana, Nlingilili Oarabile Kgosietsile. "Gravity Recovery by Kinematic State Vector Perturbation from Satellite-to-Satellite Tracking for GRACE-like Orbits over Long Arcs." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1578042687104082.
Testo completo
33
Aaron, Benjamin S. (Benjamin Samuel). "Geosynchronous satellite maneuver detection and orbit recovery using ground based optical tracking." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36175.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.<br>Includes bibliographical references (p. 115-116).<br>Geosynchronous satellite orbit maintenance is a very important issue. Satellites maneuver frequently requiring the ability to detect unknown maneuvers for target satellites and quickly recover an accurate orbit. This study uses angles only ground based optical tracking to detect maneuvers and recover orbits for geosynchronous satellites. Using the Analytical Graphics Inc. Orbit Determination Tool Kit sequential estimation software, a sequential estimation filter was "tuned" and validated in various ways. Then, a parametric study of maneuver size and time required to detect a maneuver was done via simulation. Simulated maneuvers ranging from Av's of 0.01 m/s to 1.0 m/s are discussed. Also examined are multiple methods to recover the orbit after such maneuvers are detected. Orbits are recovered for simulated maneuvers and for a real data case of unknown maneuver size. This work is important towards developing more automatic methods of detecting maneuvers for a large population of active geosynchronous satellites. Specific contributions made by this thesis include the following:<br>(cont.) the process and results of "tuning" of the sequential filter for a geosynchronous satellite using high accuracy ground based optical tracking data, the methods of orbit and covariance validation including an orbit overlap analysis and a statistical method using measurements, a parametric study for maneuver detection, and exploring methods for recovering post maneuver orbits quickly and accurately. With the tuned filter and optical tracking, simulations showed that a Av of 1.0 m/s could be detected as soon as 15 minutes after the maneuver, a Av of 0.1 m/s could be discernible within 6 hours and easily detected by 12 hours, and a Av of 0.01 m/s took from 12 to 24 hours to detect with confidence. The best demonstrated means for post-maneuver orbit recovery utilized a method of estimating the approximate maneuver time using the pre-maneuver filter orbit and an approximate post maneuver orbit followed by the "sprinkling" of a number of maneuvers over that period with Av's of 0 m/s but with finite covariances, and then filtering through that period.<br>by Benjamin S. Aaron.<br>S.M.
34
Torén, Rickard. "Comparing CNN methods for detection and tracking of ships in satellite images." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-167163.
Testo completoAbstract (sommario):
Knowing where ships are located is a key factor to support safe maritime transports, harbor management as well as preventing accidents and illegal activities at sea. Present international solutions for geopositioning in the maritime domain exist such as the Automatic Identification System (AIS). However, AIS requires the ships to constantly transmit their location. Real time imaginary based on geostationary satellites has recently been proposed to complement the existing AIS system making locating and tracking more robust. This thesis investigated and compared two machine learning image analysis approaches – Faster R-CNN and SSD with FPN – for detection and tracking of ships in satellite images. Faster R-CNN is a two stage model which first proposes regions of interest followed by detection based on the proposals. SSD is a one stage model which directly detects objects with the additional FPN for better detection of objects covering few pixels. The MAritime SATellite Imagery dataset (MASATI) was used for training and evaluation of the candidate models with 5600 images taken from a wide variety of locations. The TensorFlow Object Detection API was used for the implementation of the two models. The results for detection show that Faster R-CNN achieved a 30.3% mean Average Precision (mAP) while SSD with FPN achieved only 0.0005% mAP on the unseen test part of the dataset. This study concluded that Faster R-CNN is a candidate for identifying and tracking ships in satellite images. SSD with FPN seems less suitable for this task. It is also concluded that the amount of training and choice of hyper-parameters impacted the results.
35
Chang, Jessica S. M. EngMassachusetts Institute of Technology. "Small satellite optical communication receiver for simultaneous spatial tracking and data demodulation." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123011.
Testo completoAbstract (sommario):
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 71-72).<br>Free-space optical communications in space offer many benefits over established radio frequency based communication links; in particular, high beam directivity results in efficient power usage. Such a reduced power requirement is particularly appealing to small satellites with strict size, weight and power (SWaP) requirements. In the case of free-space optical communication, precise pointing, acquisition and tracking (PAT) of the incoming beam is necessary to close the communication link. Due to the narrow beam of the laser, the critical task of accomplishing PAT becomes increasingly arduous and often requires complex systems of optical and processing hardware to account for relative movement of the terminals. Recent developments in body pointing mechanisms have allowed small satellites to point with greater precision. In this thesis, an approach to a low-complexity PAT system that utilizes a single quad-cell photodetector as an optical spatial sensor is presented in the context of a system which exploits the body pointing capabilities of the spacecraft to perform tracking maneuvers, eschewing the need for additional dedicated optical hardware. The design and validation of this approach is presented, and preliminary results regarding the implementation of this system are discussed. In particular, we examine the implementation of the system on NASA's TeraByte InfraRed Delivery (TBIRD) demonstration.<br>National Aeronautics and Space Administrationunder Air Force Contract No. FA8702-15-D-0001<br>by Jessica S. Chang.<br>M. Eng.<br>M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
36
Narenthiran, Kanagasabapathy. "Optimisation of mobility management for mobile satellite systems resources." Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/798100/.
Testo completo
37
Haddock, Paul C. "TELEMETERY DATA COLLECTION FROM OSCAR SATELLITES." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607347.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>This paper discusses the design, configuration, and operation of a satellite station built for
the Center for Space Telemetering and Telecommunications Laboratory in the Klipsch
School of Electrical and Computer Engineering Engineering at New Mexico State
University (NMSU). This satellite station consists of a computer-controlled antenna
tracking system, 2m/70cm transceiver, satellite tracking software, and a demodulator.
The satellite station receives satellite telemetry, allows for voice communications, and
will be used in future classes. Currently this satellite station is receiving telemetry from
an amateur radio satellite, UoSAT-OSCAR-11. Amateur radio satellites are referred to as
Orbiting Satellites Carrying Amateur Radio (OSCAR) satellites.
38
Lombardo, Marco. "Numerical simulations of the orbit determination of a small sat mission for gravity investigations based on Satellite-to-Satellite Tracking." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18501/.
Testo completoAbstract (sommario):
In the recent years small satellites technology is growing up very fast. The use of a small sized spacecraft allows to reduce the costs of construction and launch without make particular compromise in terms of scientific objectives. Recently the small satellites have been used also as complement in a deep space mission and so new engineering challenges have born.
The purpose of this master thesis rely on a particular small satellites mission concept that would improve the gravity investigations accuracy of a target body but with a lower cost. This mission case is based on the employment of a pair
of small satellites that use the Satellite-to-Satellite Tracking technique to generates the observable quantities used for the orbit determination process and for the scientific analysis. These observables are two-way Doppler data obtained from the frequency shift of a stable microwave carrier transmitted between the two spacecrafts. Through these measurements it is possible to determine the static
and dynamic gravity field of a body. The utilization
of the SST, together with the small satellites technology, would certainly reduce the complexity and the costs, with an increment of estimation accuracy, but with the introduction of new potential engineering problems.
The targets of the proposed SST mission concept are Titan, Enceladus and Europa.
In each of these mission cases the two smallsats are placed on the same orbit, with a given angular separation.
The objectives of this thesis were focused on the analysis of the SST technique, the numerical simulation of the orbit determination of the spacecrafts and the obtainable accuracy of the moon's gravity field estimation. Following these targets different orbital geometries were studied, to identify the most promising configurations.
All the numerical evaluations have been conducted with the astro available at the Radio Science and Planetary Exploration Laboratory of the University of Bologna.
39
Grompone, Alessio A. "Vision-based 3D motion estimation for on-orbit proximity satellite tracking and navigation." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45863.
Testo completoAbstract (sommario):
Approved for public release; distribution is unlimited<br>The main challenge addressed in this work is to develop and validate an algorithm able to track and estimate the relative position and motion of on-orbit, un-modeled targets by using only passive vision. The algorithm developed is based on well-known image processing techniques. To achieve this goal, a number of different approaches were analyzed and compared to assess their performance for a satisfactory design. The code also has a modular general structure in order to be more flexible to changes during the implementation until best performance is reached. Artificially rendered high quality, animated videos of satellites in space and real footage provided by NASA have been used as a benchmark for the calibration and test of the main algorithm modules. The final purpose of this work is the validation of the algorithm through a hardware-in-the-loop ground experiment campaign. The development of the Floating Spacecraft Simulation Test-bed used in this work for the validation of the algorithm on real-time acquisition images was also documented in this thesis. The test-bed provides space-like illumination, stereovision and simulated weightlessness frictionless conditions. Insight on the validity of this approach, describing the performance demonstrated by the experiments, the limits of the algorithm and the main advantages and challenges related to possible future implementations in space applications, were provided by this research.
40
Littlefield, Joanne. "Information for the Elk Herd Debate in Arizona: Tracking Elk Populations by Satellite." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/622258.
Testo completo
41
Gottweis, Jason T. "Fully Transparent Computer Vision Framework for Ship Detection and Tracking in Satellite Imagery." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1547474476811329.
Testo completo
42
Regmi, Bijay. "Database Design and Optimization for Telemetric Aquatic Species-Tracking Systems." ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/honors_theses/118.
Testo completoAbstract (sommario):
Tracking an individual species has always been a challenge for scientists, especially when one has to make sure to not change its natural movement pattern. When the number of individuals being tracked is increased and water is added to the equation, the task becomes next to impossible. But thanks to technologies and tracking methods like telemetry, the task of tracking any species without affecting the natural movement pattern has not only become a reality but easily accessible to scientists. Underwater acoustic telemetry has become a standard tool for fisheries biologist to study the movement pattern of the fish (Heupel). This project develops a minimalistic database designed to meet the needs of the telemetry systems. The database is optimized for storing a large number of datasets generated by the telemetry system and also for the most common queries run against the system.
43
Zhou, Ying Fu. "A study for orbit representation and simplified orbit determination methods." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15895/1/Ying_Fu_Zhou_Thesis.pdf.
Testo completoAbstract (sommario):
This research effort is concerned with the methods of simplified orbit determination and orbit representation and their applications for Low Earth Orbit (LEO) satellite missions, particularly addressing the operational needs of the FedSat mission.
FedSat is the first Australian-built satellite in over thirty years. The microsatellite is approximately 50cm cubed with a mass of 58 kg. The satellite was successfully placed into a low-earth near-polar orbit at an altitude of 780km by the Japanese National Space Development Agency (NASDA) H-IIA launch vehicle on 14, December 2002. Since then, it has been streaming scientific data to its ground station in Adelaide almost daily. This information is used by Australian and international researchers to study space weather, to help improve the design of space computers, communication systems and other satellite technology, and for research into navigation and satellite tracking.
This research effort addresses four practical issues regarding the FedSat mission and operations.
First, unlike most satellite missions, the GPS receiver onboard FedSat operates in a duty-cycle mode due to the limitations of the FedSat power supply. This causes significant difficulties for orbit tracking, Precise Orbit Determination and scientific applications. A covariance analysis was performed before the mission launch to assess the orbit performance under different operational modes. The thesis presents the analysis methods and results.
Second, FedSat supports Ka-band tracking experiments that require a pointing accuracy of 0.03 degree. The QUT GPS group is obligated to provide the GPS precise orbit solution to meet this requirement. Ka-band tracking requests satellite orbital position at any instant time with respect to any of the observation stations. Because orbit determination and prediction software only provide satellite orbital data at a discrete time point, it is necessary to find a way to represent the satellite orbit as a continuous trajectory with discrete observation data, able to obtain the position of the satellite at the time of interest. For this purpose, an orbit interpolation algorithm using the Chebyshev polynomial was developed and applied to Ka-band tracking applications. The thesis will describe the software and results.
Third, since the launch of FedSat, investigators have received much flight GPS data. Some research was invested in the analysis of FedSat orbit performance, GPS data quality and the quality of the onboard navigation solutions. Studies have revealed that there are many gross errors in the FedSat onboard navigation solution (ONS). Although the 1-sigma accuracy of each component is about 20 m, there are more than 11 %positioning errors that fall outside +/-50m, and 5% of the errors are outside the 100mbound. The 3D RMS values would be 35m, 87m, and 173m for the above three cases respectively. The FedSat ONS uncertainties are believed to be approximately three times greater than those from other satellite missions.
Due to the high percentage of outlier solutions, it would be dangerous to use these without first applying data detection and exclusion procedures. Therefore, this thesis presents two simplified orbit determination methods that can improve the ONS. One is the "geometric method", which makes use of delta-position solutions derived from carrier phase differences between two epochs to smooth the code-based navigation solutions. The algorithms were tested using SAC-C GPS data and showing some improvement. The second method is the "dynamic method", which uses orbit dynamics information for orbit improvements.
Fourth, the FedSat ground tracking team at Adelaide use the NORAD TLE orbit for daily FedSat tracking. Research was undertaken to convert an orbit trajectory into these Two Line Elements (TLE). Algorithms for the estimation of TLE solutions from the FedSat onboard GPS navigation solutions are outlined. Numerical results have shown the effects of the unmodelled forces/perturbations in the SPG4 models for the FedSat orbit determination would reach a level of ±1000m. This only includes the orbit representation errors with TLE data sets. The total FedSat orbit propagation should include both the orbit propagation and orbit representation terms. The analysis also demonstrates that the orbit presentation error can be reduced to ±200m and ±100mlevels with the EGM4x4 and EGM10x10 gravity field models respectively. This can meet the requirements for Ka-band tracking. However, a simplified tracking program based on numerical integration has to be developed to replace the SPG4 models.
44
Zhou, Ying Fu. "A Study For Orbit Representation And Simplified Orbit Determination Methods." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15895/.
Testo completoAbstract (sommario):
This research effort is concerned with the methods of simplified orbit determination and orbit representation and their applications for Low Earth Orbit (LEO) satellite missions, particularly addressing the operational needs of the FedSat mission. FedSat is the first Australian-built satellite in over thirty years. The microsatellite is approximately 50cm cubed with a mass of 58 kg. The satellite was successfully placed into a low-earth near-polar orbit at an altitude of 780km by the Japanese National Space Development Agency (NASDA) H-IIA launch vehicle on 14, December 2002. Since then, it has been streaming scientific data to its ground station in Adelaide almost daily. This information is used by Australian and international researchers to study space weather, to help improve the design of space computers, communication systems and other satellite technology, and for research into navigation and satellite tracking. This research effort addresses four practical issues regarding the FedSat mission and operations. First, unlike most satellite missions, the GPS receiver onboard FedSat operates in a duty-cycle mode due to the limitations of the FedSat power supply. This causes significant difficulties for orbit tracking, Precise Orbit Determination and scientific applications. A covariance analysis was performed before the mission launch to assess the orbit performance under different operational modes. The thesis presents the analysis methods and results. Second, FedSat supports Ka-band tracking experiments that require a pointing accuracy of 0.03 degree. The QUT GPS group is obligated to provide the GPS precise orbit solution to meet this requirement. Ka-band tracking requests satellite orbital position at any instant time with respect to any of the observation stations. Because orbit determination and prediction software only provide satellite orbital data at a discrete time point, it is necessary to find a way to represent the satellite orbit as a continuous trajectory with discrete observation data, able to obtain the position of the satellite at the time of interest. For this purpose, an orbit interpolation algorithm using the Chebyshev polynomial was developed and applied to Ka-band tracking applications. The thesis will describe the software and results. Third, since the launch of FedSat, investigators have received much flight GPS data. Some research was invested in the analysis of FedSat orbit performance, GPS data quality and the quality of the onboard navigation solutions. Studies have revealed that there are many gross errors in the FedSat onboard navigation solution (ONS). Although the 1-sigma accuracy of each component is about 20 m, there are more than 11 %positioning errors that fall outside +/-50m, and 5% of the errors are outside the 100mbound. The 3D RMS values would be 35m, 87m, and 173m for the above three cases respectively. The FedSat ONS uncertainties are believed to be approximately three times greater than those from other satellite missions. Due to the high percentage of outlier solutions, it would be dangerous to use these without first applying data detection and exclusion procedures. Therefore, this thesis presents two simplified orbit determination methods that can improve the ONS. One is the "geometric method", which makes use of delta-position solutions derived from carrier phase differences between two epochs to smooth the code-based navigation solutions. The algorithms were tested using SAC-C GPS data and showing some improvement. The second method is the "dynamic method", which uses orbit dynamics information for orbit improvements. Fourth, the FedSat ground tracking team at Adelaide use the NORAD TLE orbit for daily FedSat tracking. Research was undertaken to convert an orbit trajectory into these Two Line Elements (TLE). Algorithms for the estimation of TLE solutions from the FedSat onboard GPS navigation solutions are outlined. Numerical results have shown the effects of the unmodelled forces/perturbations in the SPG4 models for the FedSat orbit determination would reach a level of ±1000m. This only includes the orbit representation errors with TLE data sets. The total FedSat orbit propagation should include both the orbit propagation and orbit representation terms. The analysis also demonstrates that the orbit presentation error can be reduced to ±200m and ±100mlevels with the EGM4x4 and EGM10x10 gravity field models respectively. This can meet the requirements for Ka-band tracking. However, a simplified tracking program based on numerical integration has to be developed to replace the SPG4 models.
45
Persen, Todd. "FPGA-BASED DESIGN OF A MAXIMUM-POWER-POINT TRACKING SYSTEM FOR SPACE A." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3126.
Testo completoAbstract (sommario):
Satellites need a source of power throughout their missions to help them remain operational for several years. The power supplies of these satellites, provided primarily by solar arrays, must have high efficiencies and low weights in order to meet stringent design constraints. Power conversion from these arrays is required to provide robust and reliable conversion which performs optimally in varying conditions of peak power, solar flux, and occlusion conditions. Since the role of these arrays is to deliver power, one of the principle factors in achieving maximum power output from an array is tracking and holding its maximum-power point. This point, which varies with temperature, insolation, and loading conditions, must be continuously monitored in order to react to rapid changes. Until recently, the control of maximum power point tracking (MPPT) has been implemented in microcontrollers and digital signal processors (DSPs). While DSPs can provide a reasonable performance, they do not provide the advantages that field-programmable gate arrays (FPGA) chips can potentially offer to the implementation of MPPT control. In comparison to DSP implementations, FPGAs offer lower cost implementations since the functions of various components can be integrated onto the same FPGA chip as opposed to DSPs which can perform only DSP-related computations. In addition, FPGAs can provide equivalent or higher performance with the customization potential of an ASIC. Because FPGAs can be reprogrammed at any time, repairs can be performed in-situ while the system is running thus providing a high degree of robustness. Beside robustness, this reprogrammability can provide a high level of (i) flexibility that can make upgrading an MPPT control system easy by merely updating or modifying the MPPT algorithm running on the FPGA chip, and (ii) expandability that makes expanding an FPGA-based MPPT control system to handle multi-channel control. In addition, this reprogrammability provides a level of testability that DSPs cannot match by allowing the emulation of the entire MPPT control system onto the FPGA chip. This thesis proposes an FPGA-based implementation of an MPPT control system suitable for space applications. At the core of this system, the Perturb-and-observe algorithm is used to track the maximum power point. The algorithm runs on an Alera FLEX 10K FPGA chip. Additional functional blocks, such as the ADC interface, FIR filter, dither generator, and DAC interface, needed to support the MPPT control system are integrated within the same FPGA device thus streamlining the part composition of the physical prototype used to build this control system.<br>M.S.E.E.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering
46
Aloi, Daniel N. "Electromagnetic analysis of ground multipath for satellite-based positioning systems." Ohio University / OhioLINK, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1178816934.
Testo completo
47
Warnich, Dirk J. "Tracking collar and infrastructure for leopard research." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71722.
Testo completoAbstract (sommario):
Thesis (MScEng)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: This project targeted the development of a new tracking collar, trap telemetry system
and supporting infrastructure, to aid researchers from the Cape Leopard Trust. Previously
used collar products had all proven insu cient in some capacity and remote monitoring of
trap sites was also required. Tracking collars are used to identify the movement patterns
of the leopards and through the resulting research, assist in protecting this threatened
species. In the development of the tracking collar and trap telemetry system, a high level
system design was rst formulated, identifying major components that would be required.
Alternative methods for implementation were then considered and the most optimal chosen.
Two di erent modes of communication with the collar were envisioned and designed for.
These would be used to transmit logged coordinates obtained from a GPS receiver back to
researchers. A VHF terrestrial radio link was investigated, but an Iridium Satellite based
solution was ultimately selected. An Iridium Satellite communications system was also used
for transfer of trap state data. Ultimately, a working trap telemetry system was delivered
for use by researchers. The tracking collar system had progressed to a working prototype,
requiring miniaturisation and packaging before deployment. A possible packaging solution
was also identi ed. The trap telemetry system, although displaying certain de ciencies,
provided a capability previously unavailable to researchers. With further development, there
is potential for the tracking collar to provide accurate satellite tracking and communications
in a mass and price combination not previously available.<br>AFRIKAANSE OPSOMMING: Hierdie projek het as doel die ontwikkeling van 'n nuwe opsporingshalsband, 'n lokval
telemetriese stelsel en die nodige ondersteunende infrastruktuur daarvoor. As hulpmiddels
vir navorsers van Cape Leopard Trust. Geen van die halsband produkte wat tot nou toe
gebruik is, het voldoen aan al die nodige behoeftes nie, en dit was ook nodig om die
lokvalterreine van 'n afstand te kan monitor. Die opsporingshalsbande word gebruik om
die bewegingspatrone van luiperds vas te stel en die navorsing wat daarop volg, help dat
'n bedreigde spesie bewaar word. Die ontwikkeling van die opsporingshalsband en lokval
telemetriese stelsel het begin met die formulering van 'n ho evlak stelselontwerp waarin
die hoofkomponente wat benodig sou wees ge denti seer is. Alternatiewe metodes van
bewerkstelling is daarna oorweeg en die optimale hiervan is gekies. Twee verskillende
metodes van kommunikasie met die halsband is voorgestel en ontwerp. Hierdie sou gebruik
word om die vasgelegte koordinate wat van 'n GPS ontvanger verkry is, na navorsers terug
te versend. 'n Terrestriale radioverbinding is ondersoek, maar 'n Iridium Satelliet-baseerde
oplossing is uiteindelik verkies. 'n Iridium Satelliet kommunikasie stelsel is ook gebruik
vir die oordrag van data aangaande die lokvaltoestand. Uitendelik is 'n werkende lokval
telemetriese stelsel gelewer vir dir gebruik van navorsers. Die opsporingshalsband stelsel
was nou 'n werkende prototipe, wat slegs verklein en toepaslik verpak moes word voor dit
in gebruik geneem kon word. 'n Moontlike oplossing tot die verpakkingsprobleem is ook
identi seer. Die lokval telemetriese stelsel, hoewel dit steeds tekorte toon, voorsien die
navorsers van voorheen onbekombare inligting. Met verder ontwikkeling is daar potensiaal
vir die opsporingshalsband om akkurate satellietopsporing en kommunikasie te voorsien in
'n kombinasie van laer massa, sowel as prys, soos nog nooit voorheen beskikbaar nie.
48
Mitchell, Marcella B., and Alain Thomas. "A DYNAMIC MULTI-PROTOCOL INTERFACE FOR TT&C SATELLITE BASEBAND PROCESSOR." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/605809.
Testo completoAbstract (sommario):
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>This paper presents the architecture of a new dynamic multi-protocol network interface implemented on a TT&C satellite baseband processor. Today Ethernet is the main connection of the equipment in a satellite system. Various protocols are necessary to optimize support of data exchange and are implemented using several supports such as Serial lines, Ethernet or Internet. The capability to dynamically switch from one service to another, using the most adapted interface, is the key factor for a multi-mission, multi-satellite system.
49
Adanti, Luca. "Calibrazione segmento UHF di una stazione di terra satellitare." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14709/.
Testo completoAbstract (sommario):
Il lavoro di tesi si incentra sulla validazione della catena di ricezione della stazione di terra situata nel Tecnopolo di Forlì. In particolare le attività riguardano l'implementazione della strumentazione necessaria, l'installazione dei vari software necessari allo svolgimento delle varie operazioni e in seguito la verifica del corretto funzionamento della catena di trasmissione e della ricezione di segnali provenienti dai satelliti oggetto di test di puntamento.
50
Afzulpurkar, N. V. "Kinematics, design, programming and control of a robotic platform for satellite tracking and other applications." Thesis, University of Canterbury. Mechanical Engineering, 1990. http://hdl.handle.net/10092/5829.
Testo completoAbstract (sommario):
In order to avoid the keyhole problems associated with present antenna mounting systems and to meet the requirements of acquisition and tracking for high gain and narrow beamwidth antennas, a novel antenna mount system is developed. The antenna is mounted on a microprocessor controlled robotic platform with six degrees of freedom. The mechanism is based on the principles of Stewart platform, which employes six variable length actuators constrained between a fixed base and a movable platform. This antenna mount is especially suitable for high gain antennas using high frequency band widths for marine satellite communications.
The kinematics and geometry of the parallel link mechanism has been studied in detail. The kinematic analysis for the parallel manipulator consists of developing a set of kinematic equations for the six linear actuators in terms of the "world coordinates" (Ф,θ,α,x,y,z). These kinematic equations are then solved for the "machine coordinates'" (L1 ,L2,L3,L4,L5,L6), which are the six actuator lengths. A computer simulation has been done to model the motion of the platform. The simulation has simplified the task of examining various mechanism configurations, the range of motion and the mechanism mechanical constraints.
A six motor controller board based on the motion controller microprocessors has been developed. Limited unipolar pulse width modulated servo drives are used to drive the permanent magnet DC motors of the linear actuators. A desktop computer is used as the host processor to generate the command data. The motion control microprocessors generate the velocity and acceleration profiles and drive the six axes simultaneously. The main control programme residing in the host processor schedules the overall operation. The orbital satellite bearings are calculated on a minicomputer and downloaded to the control desktop computer.
A prototype antenna mount based on the descriptions above was designed, constructed and tested for tracking a high pass and low pass of an orbiting weather satellite, (the NOAA-7). A microwave antenna mounted on the platform was found to be capable of tracking an orbital satellite throughout the visible hemisphere, although the reception tracking has not been inplemented. This antenna mount offers a light weight, structurally strong and fast dynamic response tracking system for land and marine applications.
This parallel robotic mechanism has potential for further applications such as a prepackaged portable communications system which can be deployed rapidly at remote construction sites or during civil defence emergencies. In addition it may be employed as a stabilized platform which can be used for marine VTOL aircraft recovery during rough weather. The application of this antenna mount in a low cost marine satellite communications system is emphasized since the fast dynamic response of the system will eliminate the need for an expensive stabilized platform.