Radio Occultations Using Earth Satellites

Radio Occultations Using Earth Satellites
Author: William G. Melbourne
Publisher: Wiley-Interscience
Total Pages: 680
Release: 2005
Genre: Science
ISBN:

the wave theory foundations of today's radio occultation techniques Forty years ago, the premier radio occultation problem was how to profile the atmosphere and radius of Mars using signals sent by the Mariner 4 spacecraft. Researchers then could rely on ray theory-based techniques for accurate analysis of the thin, uniform Martian atmosphere. Today's radio occultation challenges mostly involve communications platforms—and related data, instrument systems, and applications—in the Earth's own atmosphere. To deal with the density and complexity of this multilayered medium, an analytical framework that goes beyond ray theory is needed. Setting the cutting edge for the field, Radio Occultations Using Earth Satellites: A Wave Theory Treatment develops a purely wave-theoretic approach to occultation analysis. This approach yields more nuanced results than either ray or hybrid (ray/wave) methodologies offer, and proves suitable for the many variables at work in today's problems. This groundbreaking text provides: An introduction to the general theory of radio occultations Development of ray theory and scalar diffraction treatments of radio propagation processes Development of a wave theoretic treatment of the above wave propagation processes The correspondence between wave and ray theories A discussion of how to use a wave-theoretic approach to infer the refractive properties of the propagation medium from a time series set of observations of the propagated wave's phase and amplitude A comprehensive resource that clearly defines the latest topics and methodologies, Radio Occultations Using Earth Satellites is a must-have text for engineers, scientists, students, and managers in satellites communications, navigation, deep space and planetary exploration, aerospace, atmospheric science, physics, and engineering. The Deep Space Communications and Navigation Series is authored by scientists and engineers with extensive experience in astronautics, communications, and related fields. It lays the foundation for innovation in the areas of deep space navigation and communications by disseminating state-of-the-art knowledge in key technologies.

Encyclopedia of Lunar Science

Encyclopedia of Lunar Science
Author: Brian Cudnik
Publisher: Springer Nature
Total Pages: 1287
Release: 2023-05-13
Genre: Science
ISBN: 331914541X

The Encyclopedia of Lunar Science includes the latest topical data, definitions, and explanations of the many and varied facets of lunar science. This is a very useful reference work for a broad audience, not limited to the professional lunar scientist: general astronomers, researchers, theoreticians, practitioners, graduate students, undergraduate students, and astrophysicists as well as geologists and engineers. The title includes all current areas of lunar science, with the topical entries being established tertiary literature. The work is technically suitable to most advanced undergraduate and graduate students. The articles include topics of varying technical levels so that the top scientists of the field find this work a benefit as well as the graduate students and the budding lunar scientists. A few examples of topical areas are as follows: Basaltic Volcanism, Lunar Chemistry, Time and Motion Coordinates, Cosmic Weathering through Meteoritic Impact, Environment, Geology, Geologic History, Impacts and Impact Processes, Lunar Surface Processes, Origin and Evolution Theories, Regolith, Stratigraphy, Tectonic Activity, Topography, Weathering through ionizing radiation from the solar wind, solar flares, and cosmic rays.

System Earth via Geodetic-Geophysical Space Techniques

System Earth via Geodetic-Geophysical Space Techniques
Author: Frank M. Flechtner
Publisher: Springer Science & Business Media
Total Pages: 587
Release: 2010-07-10
Genre: Science
ISBN: 364210228X

Our planet is currently experiencing substantial changes due to natural phen- ena and direct or indirect human interactions. Observations from space are the only means to monitor and quantify these changes on a global and long-term p- spective. Continuous time series of a large set of Earth system parameters are needed in order to better understand the processes causing these changes, as well as their interactions. This knowledge is needed to build comprehensive Earth s- tem models used for analysis and prediction of the changing Earth. Geodesy and geophysics contribute to the understanding of system Earth through the observation of global parameter sets in space and time, such as tectonic motion, Earth surface deformation, sea level changes and gravity, magnetic and atmospheric elds. In the framework of the German geoscience research and development p- gramme GEOTECHNOLOGIEN, research projects related to the theme “Observing the Earth System from Space” have been funded within two consecutive phases since 2002, both covering 3 years. The projects address data analysis and model development using the satellite missions CHAMP, GRACE, GOCE and comp- mentary ground or airborne observations. The results of the rst phase projects have been published in the Springer book, titled “Observation of the Earth System from Space”, edited by Flury, Rummel, Reigber, Rothacher, Boedecker and Schreiber in 2006. The present book, titled “System Earth via Geodetic-Geophysical Space Techniques” summarizes in 40 scienti c papers the results of eight coordinated research projects funded in the second phase of this programme (2005–2008).

Celestial Shadows

Celestial Shadows
Author: John Westfall
Publisher: Springer
Total Pages: 727
Release: 2014-11-19
Genre: Science
ISBN: 1493915355

Much of what is known about the universe came from the study of celestial shadows. This book looks in detail at the way eclipses and other celestial shadows have given us amazing insights into the nature of the objects in our solar system and how they are even helping us discover and analyze planets that orbit stars other than our Sun. A variety of eclipses, transits, and occultations of the mooons of Jupiter and Saturn, Pluto and its satellite Charon, asteroids and stars have helped astronomers to work out their dimensions, structures, and shapes - even the existence of atmospheres and structures of exoplanets. Long before Columbus set out to reach the Far East by sailing West, the curved shadow of the Earth on the Moon during a lunar eclipse revealed that we inhabit a round world, a globe. More recently, comparisons of the sunlit and Earthlit parts of the Moon have been used to determine changes in the Earth's brightness as a way of monitoring possible effects in cloud coverage which may be related to global warming. Shadows were used by the Greek mathematician Eratosthenes to work out the first estimate of the circumference of the Earth, by Galileo to measure the heights of the lunar mountains and by eighteenth century astronomers to determine the scale of the Solar System itself. Some of the rarest and most wonderful shadows of all are those cast onto Earth by the lovely "Evening Star" Venus as it goes between the Earth and the Sun. These majestic transits of Venus occur at most two in a century; after the 2012 transit, there is not a chance to observe this phenomenon until 2117, while the more common sweep of a total solar eclipse creates one of the most dramatic and awe-inspiring events of nature. Though it may have once been a source of consternation or dread, solar eclipses now lead thousands of amateur astronomers and "eclipse-chasers" to travel the globe in order to experience the dramatic view under "totality." These phenomena are among the most spectacular available to observers and are given their full due in Westfall and Sheehan's comprehensive study.