Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

There are still many open scientific questions about the moon, including whether humans will one day be able to live there. This book looks at the history of the moon's orbit and the prospects of in situ lunar science, the radiation impact on the lunar surface, the resistance of settlement materials on the moon under the conditions of protecting humans on-site, and the preparation of humans for space missions.

Astronomy. --- Moon. --- Earth (Planet) --- Satellite

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Microvibrations management is a very important task in view of improving the quality of operation of modern satellites. Microvibrations can resonate with the structural modes of the satellite and its components and impact the results of the payload. This master thesis describes the development of a microvibration damper for reaction wheels, which are a great source of these vibrations.
In the introduction, a review of the state of the art is conducted with the aim of determining which existing solutions seem suitable for the current problem. Other solutions are proposed later in this work.
Then, a benchmarking of reaction wheels is performed as well as an analytical modelling of their dynamic behavior, in an attempt to make the analysis of reaction wheels and the subsequent design of a microvibration damper scalable. This work allowed to conclude that this scalability is not possible.
The design of the damper is thus conducted for the reaction wheel of interest. An initial trade-off is performed among all the considered vibration isolation systems. Elastomeric materials and their peculiarities are presented and silicone rubber is chosen for the present design. Finite element simulations are performed with the software Siemens NX in order to study the effect of temperature, shape and dimensions, and to compute the transfer function of the reaction wheel assembly (RWA). Based on these analyses, a baseline solution is defined, consisting of four conical elastomeric dampers providing the required attenuation. Finally, the conclusion discusses the limitations of the proposed solution and some recommendations are made for further improvements.

microvibration --- satellite --- reaction wheel --- damper --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Artificial satellites in navigation --- Artificial satellites in telecommunication. --- Communication satellites --- Communications-relay satellites --- Communications satellites --- Global satellite communications systems --- Satellite communication systems --- Telecommunication satellites --- Telecommunications satellites --- Telstar satellites --- Telecommunication --- Navigation

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Remote-sensing images --- Earth sciences --- Remote sensing --- Earth (Planet) --- Observations --- Images, Remote-sensing --- Satellite images --- Side-looking airborne radar images --- SLAR (Side-looking airborne radar) --- Cartographic materials --- Earth

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Introduction to GNSS Geodesy is a concise reference for beginners and experts in GNSS-based satellite geodesy. It covers all of the important concepts in almost a third of the space of the other GNSS books. Th e book begins with a case study in Augmented Reality to set the stage for what is to come and then moves on to the key elements of GNSS geodesy that make accurate and precise geopositioning possible. For example, it is important to understand the geodetic reference systems and the associated GNSS data processing strategies that enable both accurate and high-precision geopositioning. Chapter 2 gives an overview of GNSS constellations and signals, highlighting important characteristics. Chapter 3 then introduces reference systems in geodesy, covering such topics as time systems, geodetic datums, coordinate systems, coordinate conversions and transformations, and International Terrestrial Reference Frame. Th is lays the framework for the rest of the book. Chapters 4 and 5 dig deep into mathematical formulation of GNSS parameter estimation and observation models. All the concepts are presented clearly and concisely, with diagrams to assist reader comprehension. Chapter 6 describes Continuously Operating Reference Station (CORS) networks and their role in geodesy and definition of reference frames. Various global and regional CORS networks are presented in this section. Th e chapter also covers GNSS data and common formats such as RINEX and RTCM. Chapter 7 introduces the whole cycle of GNSS data processing, including preprocessing, ambiguity fixing, and solution reprocessing methods as commonly used in both epoch solutions and time series data. Th e book concludes with appendices on orbit modelling, GNSS linear combinations, application examples, and an example linear model.

Measuring methods in physics --- Geology. Earth sciences --- Mining industry --- Chemical technology --- Geography --- meetmethoden --- GIS (geografisch informatiesysteem) --- meettechniek --- mijnbouw --- geologie --- Global Positioning System. --- Satellite geodesy.