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CCSDS SPACE LINK EXTENSION SERVICE MANAGEMENT STANDARDS AND PROTOTYPING ACTIVITIESPietras, John 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Consultative Committee for Space Data Systems (CCSDS) is developing standards for the
interface through which spaceflight mission managers request tracking, telemetry, and command
(TT&C) and Space Link Extension (SLE) services from TT&C ground stations and networks. The
standards are intended for use not just by the spaceflight projects and networks operated by the
CCSDS member agencies, but also by commercial networks and networks operated by other
governmental agencies. As part of the process of developing the standards, several prototypes are
under development. This paper presents a summary status of both the emerging service request
standards and the prototypes that implement them.
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ACHIEVING DATA TRANSFER AND SERVICE MANAGEMENT INTEROPERABILITY IN SATELLITE CONTROL NETWORKSSunshine, Carl, Williams, Lance 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A critical area for achieving interoperability between satellite control networks is the means chosen
to interconnect Satellite Operations Centers and remote antenna systems. The CCSDS Space Link
Extension (SLE) services are good candidates for this purpose, but national security space activities
have demanding requirements for accuracy of data transfer, controlled delay, and security, which
may not be fully achievable with the existing recommendations. The US Air Force developed a test
bed to evaluate the SLE protocols during live satellite contacts, for both data transfer and
management functions such as scheduling, configuring ground resources, and status reporting.
Performance was generally satisfactory, but several extensions were found to be necessary. The
SLE services provide a promising basis for use in ground stations to support both legacy Air Force
interfaces and newer standards based satellite control services.
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Satellite Ground Station Cost/Performance AppraisalMassey, David E. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The proliferation of Low Earth Orbiting (LEO) science, earth resources and eventually global communications satellites either in orbit or planned, requires a much lower cost methodology for ground support. No longer is it economically feasible to consider a single, dedicated satellite tracking station to service a LEO spacecraft. An innovative approach is needed to lower the cost of LEO satellite data services thus contributing to the expansion of the commercial space market. This appraisal will cover the performance aspects needed for LEO tracking support and offer a unique and new solution to providing TT&C and payload services.
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Circular Knowledge Creation : A case study of knowledge creation processes within denim companies striving towards circularityPapú Carrone, Natalia Lorena January 2019 (has links)
Background – Circular business models, CBMs, are an emerging topic of interest within the textile and clothing, T&C, sector. They provide a new framework to tackle current environmental and social issues by redesigning a linear model previously base on the assumption of endless availability of fossil fuels and other natural resources. CBMs change these underlying assumptions in order to be regenerative and waste-less. A company´s knowledge has to be aligned with the overarching paradigm and assumptions that guide the business model, hence, the process of creating new knowledge to sustain this shift, appears to be essential. Knowledge creation enables businesses to continuously adapt to new contexts and prevent them from becoming obsolete. As such, it constitutes an enabler to develop the internal capabilities of companies to innovate. Purpose - This study is focused on understanding how knowledge is created within T&C companies in the shift from a linear business model to a circular one. It is of interest for the study to uncover the ways in which knowledge about circularity is created and translated into business practices. Further, it also expects to explore the companies’ main internal barriers identified in this process. Methodology – The research was conducted through a single case study with an abductive approach, building on the theoretical perspective of Nonaka and Takeuchi’s knowledge creation theory and the SECI model for knowledge conversion. Semi-structured interviews with Dutch denim company employees were the basis for collecting primary data, supplemented by secondary data gathered through archival review. The data was analysed qualitatively through thematic content analysis. Findings – Results show that knowledge creation is enabled by personal motivation, company focus on circularity and long-lasting business relationships. Several knowledge creation practices related to the dimensions of socialisation, externalisation, combination and internalisation are identified, while different levels of process and knowledge complexity can be observed within each dimension. Internal barriers hindering circular knowledge creation relate to the complexity of circular concepts, individuals´ time, personal interest and previous knowledge on the topic. System-oriented internal barriers relate to finance, scale and company focus. Further, the role of regulations, as an external system-oriented barrier, is considered of relevance for this research. Practical implications & Research limitations – This thesis creates new insights into a relatively unexplored area, knowledge creation processes in the context of CBMs. Further the specific delimitation to the denim segment within the T&C sector, shares experience and guidance with practical implications for knowledge management, from companies within a segment which has a high degree of product and process innovation compared to other T&C segments.
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Návrh a implementace algoritmu SLAM pro mobilní robotOndráček, Jan January 2015 (has links)
This diploma thesis deals with the implementation of selected simultaneous locali-zation and mapping (SLAM) algorithm for mobile robot and testing of this algo-rithm. In theoretical part there is a research that describes various existing SLAM algorithms. One of these algorithms is selected for the implementation based on the selected criteria at the end of the research. Practical part of the thesis deals with the implementation of selected SLAM algorithm in particular programming language and with its testing on real data. Computer simulation in which model of the robot travels through the model of Q Building of Mendel University in Brno is created for the purpose of testing.
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System Analysis of a Numerical Predictor-Corrector Aerocapture Guidance ArchitectureRohan Gajanan Deshmukh (10587056) 07 May 2021 (has links)
<p>Aerocapture has been envisioned as a potential orbit
insertion technique for planetary destinations with an atmosphere. Despite not
being flight proven technique, many studies found in the literature and recent
mission proposals have employed aerocapture into their respective mission
designs. The potential varying levels of trajectory dispersions experienced during
atmospheric flight at each destination drives the need for robust and
fuel-efficient guidance and control solutions. Existing guidance algorithms
have relied on tracking precomputed reference trajectories, which are computed
using significant simplifications to the flight mechanics, are not generally
designed to be fuel-efficient, and require tedious performance gain tuning.
When simulated with higher levels of uncertainty, the existing algorithms have
been shown to produce large orbit insertion errors. Furthermore, existing
flight control methodologies have been limited in scope to bank angle
modulation. While some studies have introduced new methodologies, such as drag
modulation and direct force control, they haven’t been tested at the same level
of rigor as the existing methods. Advances in on-board computational power are
allowing for modern guidance and control solutions, in the form of numerical
predictor-corrector algorithms, to be realized. This dissertation presents an
aerocapture guidance architecture based on a numerical predictor-corrector
algorithm. Optimal control theory is utilized to formulate and numerically
obtain fuel-minimizing flight control laws for lifting and ballistic vehicles.
The unified control laws are integrated into a common guidance algorithm. The
architecture is utilized to conduct Monte Carlo simulation studies of
Discovery-class and SmallSat-class aerocapture missions at various planetary
destinations.</p>
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The Principle and Performance Analysis of Spread Spectrum Microwave Unified TT&C SystemJian, Zhang, Futang, Zhang 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Several different kinds of signal are transmitted through only one carrier in microwave unified telemetry tracking & control system(MUTTCS), which has replaced separate system to accomplish all TT&C functions, and has been widely used now. This paper analyses the advantages and disadvantages of general subcarrier frequency-division MUTTCS, then the principle and performances of advanced spread spectrum MUTTCS(SS-MUTTCS) are discussed in detail. The inherent ranging ability of PN code and the speciality of spread spectrum modulation realize the complete unification including measurement of range, velocity and angle as well as telemetry, telecontrol and communication functions. At the same time, the contradiction between range and velocity measurement in precision, resolution and measuring range can be solved. With CDMA technology, the signal and equipment of multi-target or multi-station TT&C can be unified easily. SS-MUTTCS operates under low S/N, low threshold, low power spectrum density and wide spectrum range, so it meet the requirements of electronic warfare and ECM, with high performance of safety, security, anti-intercept and anti-interference. Therefore, SSMUTTCS is becoming an important trend of modern vehicle TT&C system.
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"Don't Leave the Pad Without It": Using Deployable Assets to Conduct Pre-Launch and On-Orbit TestingMorimoto, Todd, Sargent, Cliff 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / When hundreds of millions of dollars are invested in building, launching, and command/control of modern military space systems, the developers and operators need assurance that when their system achieves orbit, it will be able to "talk" with the ground network, exchanging commands, telemetry and ranging signals. Furthermore, prior to launch they need proof of compatibility with the ground data systems, showing that operational ground-based crypto keys, database parameters, and processing software are in-fact compatible with the spacecraft. This paper describes Air Force Materiel Command (AFMC), Space & Missile Center (SMC) Detachment 2's four classes of deployable test assets, emphasizing deployable's contribution to successful on-orbit performance. With not only the huge dollar investment, but even more important, the ability to execute a vital test or operational mission riding on compatibility, and launch vehicle and on-orbit test and evaluation operations the watchwords are "Don't leave the pad without it."
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Statistical Methods for Launch Vehicle Guidance, Navigation, and Control (GN&C) System Design and AnalysisRose, Michael Benjamin 01 May 2012 (has links)
A novel trajectory and attitude control and navigation analysis tool for powered ascent is developed. The tool is capable of rapid trade-space analysis and is designed to ultimately reduce turnaround time for launch vehicle design, mission planning, and redesign work. It is streamlined to quickly determine trajectory and attitude control dispersions, propellant dispersions, orbit insertion dispersions, and navigation errors and their sensitivities to sensor errors, actuator execution uncertainties, and random disturbances. The tool is developed by applying both Monte Carlo and linear covariance analysis techniques to a closed-loop, launch vehicle guidance, navigation, and control (GN&C) system. The nonlinear dynamics and flight GN&C software models of a closed-loop, six-degree-of-freedom (6-DOF), Monte Carlo simulation are formulated and developed. The nominal reference trajectory (NRT) for the proposed lunar ascent trajectory is defined and generated. The Monte Carlo truth models and GN&C algorithms are linearized about the NRT, the linear covariance equations are formulated, and the linear covariance simulation is developed. The performance of the launch vehicle GN&C system is evaluated using both Monte Carlo and linear covariance techniques and their trajectory and attitude control dispersion, propellant dispersion, orbit insertion dispersion, and navigation error results are validated and compared. Statistical results from linear covariance analysis are generally within 10% of Monte Carlo results, and in most cases the differences are less than 5%. This is an excellent result given the many complex nonlinearities that are embedded in the ascent GN&C problem. Moreover, the real value of this tool lies in its speed, where the linear covariance simulation is 1036.62 times faster than the Monte Carlo simulation. Although the application and results presented are for a lunar, single-stage-to-orbit (SSTO), ascent vehicle, the tools, techniques, and mathematical formulations that are discussed are applicable to ascent on Earth or other planets as well as other rocket-powered systems such as sounding rockets and ballistic missiles.
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Reliability analysis of safety-related digital instrumentation and control in a nuclear power plantGustafsson, Johan January 2012 (has links)
There is so far no consensus on how to develop a reliability model of safety-related digitalinstrumentation and control (I&C) in a probabilistic safety assessment (PSA) of a nuclear powerplant. The objective of this thesis is to evaluate different approaches to model digital protectionsystems in a PSA for a nuclear power plant. This is accomplished by the development of a fault treemodel of the digital protection system for a fictive and simplified nuclear power plant, that act as areference model to be used for evaluation of different design alternatives and modelling principles.Common cause failures and spurious actuation signals are the major contributors to scenariosresulting in a core damage. A PSA model has to be sufficiently detailed in order for this to berepresented in the results. The impact on results such as core damage frequency and importance ofminimal cut sets from different fail-safe, voting logic and signal validation designs are significant,too. To further examine the differences between I&C designs and significance of different PSAmodelling solutions, the degree of realism of the example should be increased. This rapidlyintroduces complexity to the models resulting in a model that is more difficult to review and resultsthat is more difficult to interpret and even much simplified models tend to get rather complex.
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