DOCSLIB.ORG

Platform-Independent Mobile Robot Communication

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Platform-Independent Mobile Robot Communication Philipp A. Baer Platform-Independent Development of Robot Communication Software kassel university press This work has been accepted by the faculty of Electrical Engineering and Computer Science of the University of Kassel as a thesis for acquiring the academic degree of Doktor der Ingenieurwissenschaften (Dr.-Ing.). Advisers: Prof. Dr. Kurt Geihs Prof. Dr. Gerhard K. Kraetzschmar Additional Doctoral Committee Members: Prof. Dr. Albert Zündorf Prof. Dr. Klaus David Defense day: 04th December 2008 Bibliographic information published by Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data is available in the Internet at http://dnb.d-nb.de. Zugl.: Kassel, Univ., Diss. 2008 ISBN print: 978-3-89958-644-2 ISBN online: 978-3-89958-645-9 URN: urn:nbn:de:0002-6453 © 2008, kassel university press GmbH, Kassel www.upress.uni-kassel.de Printed by: Unidruckerei, University of Kassel Printed in Germany Für Mutti und Mama. Mutti, du bleibst unvergessen. * 29. September 1923 = 14. Oktober 2008 Contents List of Figuresv List of Tables vii Abstract ix I Introduction1 1 Introduction3 1.1 Motivation.........................................4 1.1.1 Software Structure................................5 1.1.2 Development Methodology...........................5 1.1.3 Communication.................................6 1.1.4 Configuration and Monitoring.........................6 1.2 Problem Analysis.....................................7 1.2.1 Development Methodology...........................7 1.2.2 Communication Infrastructure........................8 1.2.3 Resource Discovery...............................8 1.3 Solution Approach....................................9 1.4 Major Results........................................ 11 1.5 Overview.......................................... 12 2 Foundations 13 2.1 Autonomous Mobile Robots............................... 13 2.1.1 Hardware Architecture............................. 14 2.1.2 Robot Software.................................. 16 2.1.3 Mobile Robot Communication......................... 19 2.2 Model-Driven Software Development......................... 20 2.2.1 Model-Driven Architecture........................... 22 2.2.2 Advantages and Drawbacks.......................... 22 2.3 Service-Oriented Architecture............................. 24 2.3.1 The Essence of a SOA.............................. 24 2.3.2 Advantages and Drawbacks.......................... 25 2.4 Networking......................................... 25 2.4.1 IEEE 802.11 Family............................... 26 2.4.2 IEEE 802.15.1................................... 27 2.4.3 Communication Models and Protocols.................... 27 2.5 Security........................................... 29 2.5.1 Authentication.................................. 29 2.5.2 Encryption..................................... 29 i 3 Related Work 33 3.1 Robot Middleware..................................... 33 3.1.1 Miro........................................ 33 3.1.2 CLARAty...................................... 35 3.1.3 SORA........................................ 36 3.1.4 Player/Stage................................... 36 3.1.5 Orocos and Orca................................. 37 3.1.6 Summary..................................... 39 3.2 Development Frameworks................................ 39 3.2.1 MARIE....................................... 40 3.2.2 Microsoft Robotics Developer Studio..................... 41 3.2.3 CoSMIC...................................... 42 3.2.4 Summary..................................... 43 3.3 Resource and Service Discovery............................ 43 3.3.1 UDDI........................................ 43 3.3.2 Zero-Configuration Networking........................ 45 3.3.3 UPnP Service Discovery............................. 46 3.3.4 Service Location Protocol............................ 47 3.3.5 Field Theoretic Service Discovery for Ad Hoc Networks......... 47 3.3.6 Summary..................................... 48 II Spica 51 4 The Spica Development Framework 53 4.1 Development Methodology............................... 54 4.2 Spica Design Decisions.................................. 55 5 Spica Modelling Language 57 5.1 SpicaML Syntax...................................... 58 5.1.1 Annotations.................................... 59 5.1.2 Semantics..................................... 59 5.1.3 Name Variants.................................. 61 5.2 Basic Concepts of SpicaML............................... 62 5.2.1 URN prefix substitutes............................. 62 5.2.2 Namespace.................................... 62 5.2.3 Identifier Generation.............................. 63 5.3 Specification of Messages................................ 64 5.3.1 Structure Characteristics............................ 65 5.3.2 Identification of Data Structures....................... 66 5.3.3 Basic Language Syntax............................. 66 5.3.4 Encoding Rule Interface............................ 67 5.4 Specification of Data Flow................................ 69 5.4.1 Data Management Containers......................... 69 5.4.2 Basic Language Syntax............................. 71 5.5 Specification of Data Filtering............................. 73 5.6 Structure of a SpicaML Model............................. 74 ii Contents 6 Model Transformation 77 6.1 Model Conversion and Representation........................ 78 6.2 Extraction of the Hash, Prefixes, and Namespaces................. 79 6.3 Extraction of Enumerations............................... 79 6.4 Extraction of Data Structures.............................. 80 6.4.1 Message Capabilities.............................. 81 6.4.2 Structure Fields.................................. 84 6.5 Extraction of Modules.................................. 85 6.5.1 Offering Message Types............................. 86 6.5.2 Requesting Message Types........................... 87 6.5.3 Data Management Containers......................... 88 6.5.4 Monitoring Capabilities............................. 89 6.6 Code Generation..................................... 91 6.6.1 StringTemplate Template Engine....................... 91 6.6.2 Spica Code Generation Approach....................... 93 6.7 Code Generation Examples............................... 95 6.7.1 Enumerations................................... 95 6.7.2 Fixed Arrays.................................... 97 6.7.3 Ontology-Supported Code Generation.................... 98 7 Monitoring Framework 101 7.1 Message Format...................................... 102 7.2 Communication Characteristics............................. 103 7.3 Application Interface................................... 104 8 Resource Discovery and Auto-Configuration 105 8.1 Mobile Robots and Discovery.............................. 105 8.2 Geminga Layout Decisions............................... 107 8.3 Geminga Client Negotiation Protocol......................... 107 8.3.1 Protocol Operation................................ 108 8.3.2 Statement Types................................. 108 8.3.3 Application Example............................... 109 8.4 Announcement....................................... 110 8.4.1 Geminga Identifier Generation........................ 110 8.4.2 Resource Type Announcement......................... 111 8.5 Matching.......................................... 112 8.6 Summary.......................................... 113 III Evaluation 115 9 Application 117 9.1 Carpe Noctem Soccer Robots.............................. 118 9.1.1 CaNoSA Architecture.............................. 119 9.1.2 Spica Integration................................. 124 9.1.3 Carpe Noctem Encoding Rules......................... 127 9.1.4 Summary..................................... 127 9.2 Miro............................................. 128 Contents iii 9.2.1 Miro Communication Infrastructure..................... 128 9.2.2 Spica Integration................................. 129 9.2.3 Summary..................................... 130 9.3 Gazebo........................................... 131 9.3.1 Simulation Architecture............................. 131 9.3.2 Spica Integration................................. 133 9.3.3 Summary..................................... 135 9.4 Availability Information................................. 135 10 Evaluation 137 10.1 Applicability........................................ 138 10.1.1 Model Orientation................................ 138 10.1.2 Code Generation................................. 141 10.1.3 Extensibility.................................... 141 10.1.4 Simplification and Weaknesses........................ 142 10.2 Resource Utilisation.................................... 143 10.2.1 Processing Overhead of the Communication Infrastructure....... 143 10.2.2 Memory Footprint................................ 147 10.2.3 Performance.................................... 150 10.3 Distribution......................................... 153 10.3.1 Failure Tolerance................................. 153 10.3.2 Scalability..................................... 153 10.4 Event Orientation..................................... 157 10.4.1 Messaging and Group Communication................... 158 10.4.2 Message-Oriented Communication and Reliability............ 159 10.4.3 Synchronisation and Arbitration....................... 160 10.5 Summary.......................................... 161 11 Conclusions 163 11.1 Requirements Revisited................................. 163 11.1.1 Development Methodology..........................
Load more

Recommended publications
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Winter Observing Notes
    Wynyard Planetarium & Observatory Winter Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Tour of the Sky with the Naked Eye NGC 457 CASSIOPEIA eta Cas Look for Notice how the constellations 5 the ‘W’ swing around Polaris during shape the night Is Dubhe yellowish compared 2 Polaris to Merak? Dubhe 3 Merak URSA MINOR Kochab 1 Is Kochab orange Pherkad compared to Polaris? THE PLOUGH 4 Mizar Alcor Figure 1: Sketch of the northern sky in winter. North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. To your right is a group of stars like the outline of a saucepan standing up on it’s handle. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The top two stars are called the Pointers. Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white-hot. 2. Use the Pointers to guide you to the left, to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the right are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris. Check with binoculars. © Rob Peeling, CaDAS, 2007 version 2.0 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Polaris, Kochab and Pherkad mark the constellation Ursa Minor, the Little Bear.
    [Show full text]
  • Early China DID BABYLONIAN ASTROLOGY
    Early China http://journals.cambridge.org/EAC Additional services for Early China: Email alerts: Click here Subscriptions: Click here Commercial reprints: Click here Terms of use : Click here DID BABYLONIAN ASTROLOGY INFLUENCE EARLY CHINESE ASTRAL PROGNOSTICATION XING ZHAN SHU ? David W. Pankenier Early China / Volume 37 / Issue 01 / December 2014, pp 1 - 13 DOI: 10.1017/eac.2014.4, Published online: 03 July 2014 Link to this article: http://journals.cambridge.org/abstract_S0362502814000042 How to cite this article: David W. Pankenier (2014). DID BABYLONIAN ASTROLOGY INFLUENCE EARLY CHINESE ASTRAL PROGNOSTICATION XING ZHAN SHU ?. Early China, 37, pp 1-13 doi:10.1017/eac.2014.4 Request Permissions : Click here Downloaded from http://journals.cambridge.org/EAC, by Username: dpankenier28537, IP address: 71.225.172.57 on 06 Jan 2015 Early China (2014) vol 37 pp 1–13 doi:10.1017/eac.2014.4 First published online 3 July 2014 DID BABYLONIAN ASTROLOGY INFLUENCE EARLY CHINESE ASTRAL PROGNOSTICATION XING ZHAN SHU 星占術? David W. Pankenier* Abstract This article examines the question whether aspects of Babylonian astral divination were transmitted to East Asia in the ancient period. An often-cited study by the Assyriologist Carl Bezold claimed to discern significant Mesopotamian influence on early Chinese astronomy and astrology. This study has been cited as authoritative ever since, includ- ing by Joseph Needham, although it has never been subjected to careful scrutiny. The present article examines the evidence cited in support of the claim of transmission. Traces of Babylonian Astrology in the “Treatise on the Celestial Offices”? In , the Assyriologist Carl Bezold published an article concerning the Babylonian influence he claimed to discern in Sima Qian’s 司馬遷 and Sima Tan’s 司馬談 “Treatise on the Celestial Offices” 天官書 (c.
    [Show full text]
  • IAU Division C Working Group on Star Names 2019 Annual Report
    IAU Division C Working Group on Star Names 2019 Annual Report Eric Mamajek (chair, USA) WG Members: Juan Antonio Belmote Avilés (Spain), Sze-leung Cheung (Thailand), Beatriz García (Argentina), Steven Gullberg (USA), Duane Hamacher (Australia), Susanne M. Hoffmann (Germany), Alejandro López (Argentina), Javier Mejuto (Honduras), Thierry Montmerle (France), Jay Pasachoff (USA), Ian Ridpath (UK), Clive Ruggles (UK), B.S. Shylaja (India), Robert van Gent (Netherlands), Hitoshi Yamaoka (Japan) WG Associates: Danielle Adams (USA), Yunli Shi (China), Doris Vickers (Austria) WGSN Website: https://www.iau.org/science/scientific_bodies/working_groups/280/ ​ WGSN Email: [email protected] ​ The Working Group on Star Names (WGSN) consists of an international group of astronomers with expertise in stellar astronomy, astronomical history, and cultural astronomy who research and catalog proper names for stars for use by the international astronomical community, and also to aid the recognition and preservation of intangible astronomical heritage. The Terms of Reference and membership for WG Star Names (WGSN) are provided at the IAU website: https://www.iau.org/science/scientific_bodies/working_groups/280/. ​ ​ ​ WGSN was re-proposed to Division C and was approved in April 2019 as a functional WG whose scope extends beyond the normal 3-year cycle of IAU working groups. The WGSN was specifically called out on p. 22 of IAU Strategic Plan 2020-2030: “The IAU serves as the ​ internationally recognised authority for assigning designations to celestial bodies and their surface features. To do so, the IAU has a number of Working Groups on various topics, most notably on the nomenclature of small bodies in the Solar System and planetary systems under Division F and on Star Names under Division C.” WGSN continues its long term activity of researching cultural astronomy literature for star names, and researching etymologies with the goal of adding this information to the WGSN’s online materials.
    [Show full text]
  • Introduction the Constellations of the Winter
    Introduction The winter sky is an excellent place to begin exploring the constellations that make up the night sky. Orion is the key, or signpost, for locating many of the other constellations in the winter sky. There are two convenient ways to locate all of the main constellations around Orion once Orion is located. Fortunately, Orion is easy to locate and well known to most people. The first way is to follow lines made by pairs of stars in Orion. The second way is to locate the great winter Orion is the key for hexagon of bright star around Orion. cracking the winter sky. The Constellations of the Winter Sky If you live in the northern latitudes and you scan the sky from the southern horizon to the region overhead, you should be able to see the following constellations on a clear winter night: Orion the Hunter, Canis Major the Great Dog, Canis Minor the Little Dog, Taurus the Bull, Auriga the Charioteer, Gemini the Twins and the Pleiades star cluster. (See the map on the next page). In Greek mythology, Orion was a great hunter who eventually offended the gods, especially Apollo. Apollo tricked Artemis, the Goddess of the hunt, into shooting Orion on a bet. When she discovered that she had shot Orion, she quickly lifted him to the heavens and made him immortal, where he now hunts eternally with his two dogs, Canis Major and Canis Minor. In front of him is his prey Taurus the Bull. The myths surrounding Auriga the Charioteer vary, but it is an ancient constellation dating back to at least to the Ancient Greeks.
    [Show full text]
  • Radial Velocity Transit Animation by European Southern Observatory Animation by NASA Goddard Media Studios
    Courtney Dressing Assistant Professor at UC Berkeley The Space Astrophysics Landscape for the 2020s and Beyond April 1, 2019 Credit: NASA David Charbonneau (Co-Chair), Scott Gaudi (Co-Chair), Fabienne Bastien, Jacob Bean, Justin Crepp, Eliza Kempton, Chryssa Kouveliotou, Bruce Macintosh, Dimitri Mawet, Victoria Meadows, Ruth Murray-Clay, Evgenya Shkolnik, Ignas Snellen, Alycia Weinberger Exoplanet Discoveries Have Increased Dramatically Figure Credit: A. Weinberger (ESS Report) What Do We Know Today? (Statements from the ESS Report) • “Planetary systems are ubiquitous and surprisingly diverse, and many bear no resemblance to the Solar System.” • “A significant fraction of planets appear to have undergone large-scale migration from their birthsites.” • “Most stars have planets, and small planets are abundant.” • “Large numbers of rocky planets [have] been identified and a few habitable zone examples orbiting nearby small stars have been found.” • “Massive young Jovians at large separations have been imaged.” • “Molecules and clouds in the atmospheres of large exoplanets have been detected.” • ”The identification of potential false positives and negatives for atmospheric biosignatures has improved the biosignature observing strategy and interpretation framework.” Radial Velocity Transit Animation by European Southern Observatory Animation by NASA Goddard Media Studios How Did We Learn Those Lessons? Astrometry Direct Imaging Microlensing Animation by Exoplanet Exploration Office at NASA JPL Animation by Jason Wang Animation by Exoplanet Exploration Office at NASA JPL Exoplanet Science in the 2020s & Beyond The ESS Report Identified Two Goals 1. “Understand the formation and evolution of planetary systems as products of the process of star formation, and characterize and explain the diversity of planetary system architectures, planetary compositions, and planetary environments produced by these processes.” 2.
    [Show full text]
  • The Magic Valley Astronomical Society Notes from the President February
    February Highlights Notes from the President Feb. 1st, 6:45 to 9:00 PM Our first general membership meeting for the New Year will be held at 7:00 P.M. on Satur- Family night telescope day the 12th of February, 2011. We will be meeting at the Herrett Center, on the College of viewing. Centennial Obs. Southern Idaho Campus. Admission: $1.50, free for children 6 and under. Free Tom Gilbertson will host our annual telescope workshop "I Have a New Telescope, Now with paid planetarium admis- What?" If you are new to the hobby or if you have new equipment that you would like as- sion. sistance in learning how to operate, please bring it along (as well as any instruction manu- als) and our members will be happy to provide you with whatever assistance is required. Feb 12th, 7:00 pm to mid- This event is open to the general public and we encourage non-members to join us for this night Monthly Membership evening. General Meeting and Monthly free star party. Members in attendance will pair off with new (or old) telescope owners during the break- out sessions and teach them how to operate their new telescope (or old). We could use a Feb 15th, 7:00 to 9:00 PM lot of help from our members, so that no one has to wait to be helped. We had a good turn Family night telescope out last year and we expect more this year as well. Following the meeting we will take viewing. Centennial Obs. everyone with their telescopes up to the Stargazer’s Deck at the Centennial Observatory Admission: $1.50, free for for a evening of observing.
    [Show full text]
  • • Methods. on 2012 Feb 29, the Extrasolar Planets Encyclopaedia (Exoplanet.Eu) Tabulated 699 Planet Candidates in 558 Plane
    • Context. Young exoplanetary systems with ages τ ≤ 600 Ma (i.e. Hyades-like or younger) provide constraints on the time scale and mechanism of planet formation and on the planet evolution (orbital migration, late heavy bombardment...). Apart from the very young “planet” candidates found by direct imaging (around e.g. HR 8799, 2M1207-39 or AB Pic), some young planet candidates have been found with the radial velocity method, such as HD 70573b (Setiawan et al. 2007) in the Hercules-Lyra subgroup of the Local Association or the controversial TW Hya b and BD+20 1790b (Setiawan et al. 2008; Hernán-Obispo et al. 2010). On the other hand, there may be old exoplanetary systems, whose stars belong to the thick disc or even the Galactic halo (CD-36 1052b, Setiawan et al. 2010). • Aims. We search for bright Hipparcos stars with radial-velocity planets that are member candidates in young moving groups (Montes et al. 2001), such as the Hyades, IC 2391, Ursa Majoris and Castor superclusters and the Local Association (τ = 100-600 Ma), and very young moving groups like β Pictoris or TW Hydrae (τ < 100 Ma). Generally, these stars are discarded from accurate radial-velocity searches based on activity indicators, but there might be young stars that passed the rejection filter (e.g. HD 81040, τ ~ 700 Ma; Sozzetti et al. 2006). We also look for old exoplanet host stars in the Galactic thick disc and the thin-thick transition. • Methods. On 2012 Feb 29, the Extrasolar Planets Encyclopaedia (exoplanet.eu) tabulated 699 planet candidates in 558 planetary systems detected by radial velocity (93 multiple planet systems).
    [Show full text]
  • Lists and Charts of Autostar Named Stars
    APPENDIX A Lists and Charts of Autostar Named Stars Table A.I provides a list of named stars that are stored in the Autostar database. Following the list, there are constellation charts which show where the stars are located. The names are in alphabetical orderalong with their Latin designation (see Appendix B for complete list ofconstellations). Names in brackets 0 in the table denote a different spelling to one that is known in the list. The star's co-ordinates are set to the same as accuracy as the Autostar co-ordinates i.e. the RA or Dec 'sec' values are omitted. Autostar option: Select Item: Object --+ Star --+ Named 215 216 Appendix A Table A.1. Autostar Named Star List RA Dec Named Star Fig. Ref. latin Designation Hr Min Deg Min Mag Acamar A5 Theta Eridanus 2 58 .2 - 40 18 3.2 Achernar A5 Alpha Eridanus 1 37.6 - 57 14 0.4 Acrux A4 Alpha Crucis 12 26.5 - 63 05 1.3 Adara A2 EpsilonCanis Majoris 6 58.6 - 28 58 1.5 Albireo A4 BetaCygni 19 30.6 ++27 57 3.0 Alcor Al0 80 Ursae Majoris 13 25.2 + 54 59 4.0 Alcyone A9 EtaTauri 3 47.4 + 24 06 2.8 Aldebaran A9 Alpha Tauri 4 35.8 + 16 30 0.8 Alderamin A3 Alpha Cephei 21 18.5 + 62 35 2.4 Algenib A7 Gamma Pegasi 0 13.2 + 15 11 2.8 Algieba (Algeiba) A6 Gamma leonis 10 19.9 + 19 50 2.6 Algol A8 Beta Persei 3 8.1 + 40 57 2.1 Alhena A5 Gamma Geminorum 6 37.6 + 16 23 1.9 Alioth Al0 EpsilonUrsae Majoris 12 54.0 + 55 57 1.7 Alkaid Al0 Eta Ursae Majoris 13 47.5 + 49 18 1.8 Almaak (Almach) Al Gamma Andromedae 2 3.8 + 42 19 2.2 Alnair A6 Alpha Gruis 22 8.2 - 46 57 1.7 Alnath (Elnath) A9 BetaTauri 5 26.2
    [Show full text]
  • Double & Multiple Stars — Spring Semester
    ASTR 110L Name: Spring 2006 Double & Multiple Stars — Spring Semester 1. (7 pts.) For each of the double (or multiple) star systems that you are able to observe, sketch and/or write the following characteristics: a. Relative brightness between the two (or more) members (when sketching, use heavier vs. lighter dots) b. Apparent separation of the two (or more) members (sketch separation wider or closer relative to the other systems seen tonight) c. Colors of the two (or more) members (note in writing) d. Any other distinguishing features that you notice. 2. a. (2 pts.) What is a true binary, and how is it different from a purely visual double (also known as an optical double)? b. (1 pt.) What is a spectroscopic binary? 3. a. (1 pt.) Suppose there is a binary system whose orbital plane is exactly “edge-on” as viewed from Earth. How will its appearance vary over the course of one orbit? (You may use simple sketches to illustrate your answer.) b. (1 pt.) Suppose there is a second binary system whose orbital plane is exactly “face-on” as viewed from Earth. How will its appearance vary over the course of one orbit? (You may use simple sketches to illustrate your answer.) c. (1 pt.) The above two situations are special cases. How would you expect the appearance of most binary systems to change over the course of their orbits? (You may use simple sketches to illustrate your answer.) d. (1 pt.) Eclipsing binaries belong to which one of the above special cases? 4. Suppose there are two binary systems, binary system I and binary system II.
    [Show full text]
  • The Skyscraper 2008 01.Indd
    The Skyscraper Vol. 35 no. 1 The monthly publication of The Skyscraper January 2008 January Meeting & Member Presentations FRIDAY, JANUARY 4TH AT NORTH SCITUATE COMMUNITY CENTER Remote and Robotic Observatories, Observe While You Sleep by Bob Napier Amateur Astronomical Society of Rhode Island 3D Astronomy presentation by Gerry Dyck 47 Peeptoad Road North Scituate, RI 02857 40 Years of Comet Observing www.theskyscrapers.org by Rick Lynch President Glenn Jackson DIRECTIONS TO THE COMMUNITY CENTER: From Seagrave Observatory: North 1st Vice President Scituate Community Center is the first building on the right side going Steve Hubbard south on Rt. 116, after the intersection of Rt. 6 Bypass (also Rt. 101) and 2nd Vice President Rt. 116, in N. Scituate. Famous Pizza is on the corner of that intersection. Kathy Siok Parking is across the street from the Community Center. Secretary Nichole Mechnig ANUARY IN THIS ISSUE Treasurer J 2008 PRESIDENT’S MESSAGE 2 Jim Crawford 7:30PM January Meeting North Scituate Community Glenn Jackson F4RIDAY Members at Large Center METEOR SHOWER 2 Jim Brenek PROSPECTS FOR 2008 Joe Sarandrea 7:00PM Public Observing Night Dave Huestis Seagrave Observatory, WINTER DOUBLE STARS: 3 Trustees SATURDAY5 weather permitting GEMINI Tracey Haley Glenn Chaple Bob Horton 7:00PM Public Observing Night Jerry Jeffrey Seagrave Observatory, ULTRAVIOLET SURPRISE 4 PATRICK L. BARRY & TONY S12ATURDAY weather permitting Librarian PHILLIP S Tom Barbish 7:00PM Public Observing Night DECEMBER MEETING 5 Editor Seagrave Observatory, NOTES STEVE HUB B ARD Jim Hendrickson S19ATURDAY weather permitting TREASURER’S REPORT 5 7:00PM Public Observing Night See back page for directions to JIM CRAW FORD Seagrave Observatory, Seagrave Observatory.
    [Show full text]
  • Simulating the Escaping Atmospheres of Hot Gas Planets in the Solar Neighborhood? M
    Astronomy & Astrophysics manuscript no. salz_hdyn_esc c ESO 2018 September 27, 2018 Simulating the escaping atmospheres of hot gas planets in the solar neighborhood? M. Salz1, S. Czesla1, P. C. Schneider2;1, J. H. M. M. Schmitt1 1 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: [email protected] 2 European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands Submitted 16 March 2015 / Accepted 5 November 2015 ABSTRACT Absorption of high-energy radiation in planetary thermospheres is generally believed to lead to the formation of planetary winds. The resulting mass-loss rates can affect the evolution, particularly of small gas planets. We present 1D, spherically symmetric hy- drodynamic simulations of the escaping atmospheres of 18 hot gas planets in the solar neighborhood. Our sample only includes strongly irradiated planets, whose expanded atmospheres may be detectable via transit spectroscopy using current instrumentation. The simulations were performed with the PLUTO-CLOUDY interface, which couples a detailed photoionization and plasma simula- tion code with a general MHD code. We study the thermospheric escape and derive improved estimates for the planetary mass-loss rates. Our simulations reproduce the temperature-pressure profile measured via sodium D absorption in HD 189733 b, but show still unexplained differences in the case of HD 209458 b. In contrast to general assumptions, we find that the gravitationally more tightly bound thermospheres of massive and compact planets, such as HAT-P-2 b are hydrodynamically stable. Compact planets dispose of the radiative energy input through hydrogen Lyα and free-free emission.
    [Show full text]