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SAT (Educational test).

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Comprehensive, Rigorous Prep for the SAT. Every year students pay 600 and more to test prep companies to prepare for the new SAT. Now you can get the same SAT preparation in a book. SAT Prep Course provides the equivalent of a 2-month, 50-hour course. The SAT is challenging but it can be mastered through hard work, analytical thought, and by training yourself to think like an SAT test writer. Many of the exercises in this book are designed to prompt you to think like an SAT test writer. For example, in the SAT math section, you will find Duals. These are pairs of similar SAT problems in which only one property is different. They illustrate the process of creating SAT questions. Features:. * Math: Twenty-two chapters provide comprehensive review of SAT math, including the new concepts from Algebra II. * Reading: Develop the ability to spot places from which questions are likely to be drawn as you read a passage. (pivotal words, counter-premises, etc.). * Writing: Comprehensive analysis of the essay, including writing techniques, punctuation, grammar, rhetoric, and style. * Vocabulary: Learn the essential 4000 SAT words and the 400 high-frequency words. * Mentor Exercises: These exercises provide hints, insight, and partial solutions to ease your transition from seeing SAT problems solved to solving them on your own.

SAT (Educational test) --- College entrance achievement tests

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Every year students pay 600 and more to test prep companies to prepare for the new SAT. Now you can get the same SAT preparation in a book. SAT Prep Course provides the equivalent of a two month, 50 hour course. The new SAT is challenging but it can be mastered through hard work, analytical thought, and by training yourself to think like a SAT test writer.

SAT (Educational test) --- Universities and colleges --- SAT I (Educational test) --- SAT II (Educational test) --- Scholastic Aptitude Test --- Scholastic Assessment Test --- Scholastic Assessment Test I: Reasoning Test --- Scholastic Assessment Test II: Subject Tests --- Examinations --- Entrance examinations

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The search for life beyond our world necessarily involves the search for exoplanets with Earth-like characteristics. The progress of astrophysics now makes it possible to search for po- tentially habitable planets outside the solar system. This is especially achieved by looking for biological signatures in the spectral footprint of planetary atmospheres. This quest is considered to be one of the main objectives of modern astrophysics and exoplanetology.
The scientific community’s interest in exoplanet research has increased in recent years, par- ticularly in direct observation techniques, such as nulling interferometry, which allows exoplan- ets to be detected and resolved directly from their host star. After failing to develop large-scale space-based interferometry missions in the early 2000s, the first task would be to prove the feasibility of this technique in space. This thesis focuses on a Small Sat platform that could achieve this objective of a technological demonstrator. Besides, the mission also has a scientific objective which is to observe the 5 nearest stellar systems that host exoplanets.
This paper focuses on the observation strategy of the proposed platform and in particular on the observation possibilities provided by several orbits. Simulations are carried out for a whole year and the visibility performance of each orbit is studied. These analyses will allow an optimal design mission by maximizing the use of the platform by avoiding as much as possible the occultation times of the targeted stars.

observation strategy --- space-based interferometry --- Small Sat --- orbit design --- exoplanet. --- occultation --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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This master thesis is dedicated to the study of single mode fibers as spatial filter in a space-based nulling interferometer. They are used to decrease the requirements on the wavefront quality that an adaptive system needs to achieve.

In order to do so, a mathematical model of the coupling efficiency of a single mode fiber placed at the focus of a telescope was developed. The model is based on the Gaussian approximation of the fundamental mode LP_01 that is propagated in the single mode fiber. Also, the model is based on the theory of Fourier optics in order to determine the electric field at the input of the fiber. The model allows to compute the coupling efficiency for any static aberrations. Also, the point spread functions of a circular pupil subjected to different aberrations are simulated thanks to the fast fourier transform algorithm.

The study is performed in the waveband [3-7] µm in order to develop a nulling interferometer for exoplanets detections. The diffraction limited performances of the system are analysed. After that, the effect of static aberrations on the coupling efficiency is analysed. Then, the simulation of typical aberrations encountered in space is performed. They represent non common path aberrations (NCPA). 

The simulation of the model proves that the coupling efficiency drops from 81.45% (diffraction limited performance) to 30 % when 120 Zernike polynomials are used to represent NCPA. In order to get a RMS wavefront error below 0.1 rad a deformable mirror capable of reproducing the first 115 Zernike polynomials is needed.

Space interferometry --- Single mode fiber --- Adaptive optics --- Small Sat --- Ingénierie, informatique & technologie > Ingénierie aérospatiale