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Showing 1 to 16 of 16 for “"Pointing Accuracy"”.
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Control and Sensor Development on a Four-Wheel Pyramidal Reaction Wheel Platform
… the effects of conjoining sensors to maximize pointing accuracy. Furthermore, the system will incorporate a star tracker in conjunction with a Simulated Star Field (SSF) to better estimate the PRWP orientation. For the sake of this document, however, the goal is to implement a gyroscope, wheel …
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Development of a CubeSat Instrument for Microgravity Particle Damper Performance Analysis
<p>Spacecraft pointing accuracy and structural longevity requirements often necessitate auxiliary vibration dissipation mechanisms. However, temperature sensitivity and material degradation limit the effectiveness of traditional damping techniques in space. Robust particle damping technology offers …
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Design and utility assessment of attitude control systems for EVA task performance
… from spacecraft systems capable of maintaining pointing stability during critical operations. The addition of single-gimbal control moment gyroscopes (CMGs) to the attitude control system of these spacecraft could substantially improve the stability and pointing accuracy of the platform and …
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Optimal rejection of nonstationary narrowband disturbances for flexible systems
… and optimal allocation of resources, such as pointing accuracy and onboard fuel utilization, are of primary concern in the design and operation of precision pointing spacecraft. Ironically, internal spacecraft instruments and reaction control actuators often act as sources of narrowband …
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Numerical analysis of a tape spring hinge folded about two axes
… is important in ensuring safety, deployment accuracy as well as optimizing cost of the structure. In an effort to learn more about the folding and deployment properties, finite element software, Abaqus\u2122, was used to analyze a hinge using multidirectional bending. The analysis involved …
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Microwave Radiometer (MWR) Evaluation of Multi-Beam Satellite Antenna Boresight Pointing Using Land-Water Crossings, for the Aquarius/SAC-D Mission
… an on-orbit validation of the MWR antenna beam pointing, using calculated MWR instantaneous field of view (IFOV) centers, provided in the CONAE L-1B science data product. This procedure compares L-1B MWR IFOV centers at land/water crossings against high-resolution coastline maps. MWR IFOV …
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Adaptive Control of VSCMGs for Satellite Attitude Tracking
… allow satellites to obtain high levels of pointing accuracy with minimal fuel expenditure. However, uncertainty in these devices can significantly degrade their performance. Additionally, the available bandwidth of the actuators can also degrade performance. In this thesis, we develop …
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Improving attitude determination and control of resource-constrained CubeSats using unscented Kalman filtering
… benefits applications that require precise pointing, such as imaging and active tracking of specific targets, laser communications, and coordinated activity and observations among multiple CubeSats. We were able to achieve better than our pointing error goal of 0.05', and found that the …
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Modeling of a gimbal azimuth drive and simulation of control techniques
… defined. Static performance metrics such as pointing accuracy are easier to predict and can be related to position sensor resolution and compliance in the structure and drive. Dynamic performance metrics such as rate tracking and bandwidth are much more difficult to estimate. These dynamic …
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Integrated modeling and dynamics simulation for the next generation space telescope
… of view of maintaining a milli-arcsecond level pointing accuracy and diffraction limited wavefront performance in the presence of dynamic onboard disturbances during science observations. This is due to the fact that NGST will make extensive use of deployable, inflatable and lightweight …
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Portable optical ground stations for satellite communication
… receive terminals. Arcsecond to sub-arcsecond pointing is required from both the space terminal and the ground station. While existing lasercom ground stations have primarily utilized professional telescopes at observatory-class facilities, making optical ground stations more affordable and …
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A planar comparison of actuators for vibration control of flexible structures
… damping, which, when coupled with the stringent pointing accuracy and vibration control requirements imposed on these systems, bring about interesting control problems. Addressing these problems has called for the use of active vibration control. Up to now, two of the most popular means for …
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Development of Hardware and Efficient, Robust Control Algorithms for a Nanosatellite Reaction Control System
… modulated controllers are proposed for fine pointing control of satellites. Performance of these controllers are studied across a range of disturbance torque magnitudes and pointing accuracy requirements, and compared to existing methods where possible. Successive convexification is studied …
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Computational Methods to Improve Satellite Attitude Determination and Control with a Focus on Autonomy, Generalizability, and Underactuation
… ADCS approaches are designed for constant pointing goals, high accuracy sensors, powerful actuators, or larger, high-inertia satellites. Many modern satellites are small satellites (tens of kilograms or less), with lower-cost actuators and sensors, and may have more complicated attitude …
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International Space Station Remote Sensing Pointing Analysis
… factors contributing to drift and jitter, accuracy of pointing data and target and instrument accuracies. Finally, there is a brief discussion of image processing to address any post error correction options.
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Control de seguimiento solar de alta precisión con autocalibración
… This work describes the development of high accuracy sun tracking control equipment, to be integrated in high concentration photovoltaic systems. In order to achieve the sub degree accuracies required by these photovoltaic concentrators, a new control approach is presented that primarily …