Beta Angle Orbit Type
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DTA Scoring Form
Daytime Astronomy SHADOWS Score Form Date ____/____/____ Student _______________________________________ Rater _________________ Problem I. (Page 3) Accuracy of results Draw a dot on this map to show where you think Tower C is. Tower C is in Eastern US Tower C is in North Eastern US Tower C is somewhere in between Pennsylvania and Maine Modeling/reasoning/observation How did you figure out where Tower C is? Matched shadow lengths of towers A and B/ pointed flashlight to Equator Tried different locations for tower C/ inferred location of tower C Matched length of shadow C/considered Latitude (distance from Equator) Matched angle of shadow C/ considered Longitude (East-West direction) Problem II. (Page 4) Accuracy of results How does the shadow of Tower A look at 10 AM and 3 PM?... Which direction is the shadow moving? 10 AM shadow points to NNW 10 AM shadow is shorter than noon shadow 3 PM shadow points to NE 3 PM shadow is longer than noon shadow Clockwise motion of shadows Modeling/reasoning/observation How did you figure out what the shadow of Tower A looks like at 10 AM and 3 PM? Earth rotation/ "Sun motion" Sunlight coming from East projects a shadow oriented to West Sunlight coming from West projects a shadow oriented to East Sunlight coming from above us projects a shadow oriented to North Sun shadows are longer in the morning than at noon Morning Sun shadows become shorter and shorter until its noon The shortest Sun shadow is at noon Sun shadows are longer in the afternoon than at noon Afternoon Sun shadows become longer and longer until it gets dark (Over, please) - 1 - 6/95 Problem III. -
Mission Design for the Lunar Reconnaissance Orbiter
AAS 07-057 Mission Design for the Lunar Reconnaissance Orbiter Mark Beckman Goddard Space Flight Center, Code 595 29th ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE February 4-8, 2006 Sponsored by Breckenridge, Colorado Rocky Mountain Section AAS Publications Office, P.O. Box 28130 - San Diego, California 92198 AAS-07-057 MISSION DESIGN FOR THE LUNAR RECONNAISSANCE ORBITER † Mark Beckman The Lunar Reconnaissance Orbiter (LRO) will be the first mission under NASA’s Vision for Space Exploration. LRO will fly in a low 50 km mean altitude lunar polar orbit. LRO will utilize a direct minimum energy lunar transfer and have a launch window of three days every two weeks. The launch window is defined by lunar orbit beta angle at times of extreme lighting conditions. This paper will define the LRO launch window and the science and engineering constraints that drive it. After lunar orbit insertion, LRO will be placed into a commissioning orbit for up to 60 days. This commissioning orbit will be a low altitude quasi-frozen orbit that minimizes stationkeeping costs during commissioning phase. LRO will use a repeating stationkeeping cycle with a pair of maneuvers every lunar sidereal period. The stationkeeping algorithm will bound LRO altitude, maintain ground station contact during maneuvers, and equally distribute periselene between northern and southern hemispheres. Orbit determination for LRO will be at the 50 m level with updated lunar gravity models. This paper will address the quasi-frozen orbit design, stationkeeping algorithms and low lunar orbit determination. INTRODUCTION The Lunar Reconnaissance Orbiter (LRO) is the first of the Lunar Precursor Robotic Program’s (LPRP) missions to the moon. -
Final Report Venus Exploration Targets Workshop May 19–21
Final Report Venus Exploration Targets Workshop May 19–21, 2014, Lunar and Planetary Institute, Houston, TX Conveners: Virgil (Buck) Sharpton, Larry Esposito, Christophe Sotin Breakout Group Leads Science from the Surface Larry Esposito, Univ. Colorado Science from the Atmosphere Kevin McGouldrick, Univ. Colorado Science from Orbit Lori Glaze, GSFC Science Organizing Committee: Ben Bussey, Martha Gilmore, Lori Glaze, Robert Herrick, Stephanie Johnston, Christopher Lee, Kevin McGouldrick Vision: The intent of this “living” document is to identify scientifically important Venus targets, as the knowledge base for this planet progresses, and to develop a target database (i.e., scientific significance, priority, description, coordinates, etc.) that could serve as reference for future missions to Venus. This document will be posted in the VEXAG website (http://www.lpi.usra.edu/vexag/), and it will be revised after the completion of each Venus Exploration Targets Workshop. The point of contact for this document is the current VEXAG Chair listed at ABOUT US on the VEXAG website. Venus Exploration Targets Workshop Report 1 Contents Overview ....................................................................................................................................................... 2 1. Science on the Surface .............................................................................................................................. 3 2. Science within the Atmosphere ............................................................................................................... -
Exploring Solar Cycle Influences on Polar Plasma Convection
Comparison of Terrestrial and Martian TEC at Dawn and Dusk during Solstices Angeline G. Burrell1 Beatriz Sanchez-Cano2, Mark Lester2, Russell Stoneback1, Olivier Witasse3, Marco Cartacci4 1Center for Space Sciences, University of Texas at Dallas 2Radio and Space Plasma Physics, University of Leicester 3European Space Agency, ESTEC – Scientific Support Office 4Istituto Nazionale di Astrofisica, Istituto di Astrofisica e Planetologia Spaziali 52nd ESLAB Symposium Outline • Motivation • Data and analysis – TEC sources – Data selection – Linear fitting • Results – Martian variations – Terrestrial variations – Similarities and differences • Conclusions Motivation • The Earth and Mars are arguably the most similar of the solar planets - They are both inner, rocky planets - They have similar axial tilts - They both have ionospheres that are formed primarily through EUV and X- ray radiation • Planetary differences can provide physical insights Total Electron Content (TEC) • The Global Positioning System • The Mars Advanced Radar for (GPS) measures TEC globally Subsurface and Ionosphere using a network of satellites and Sounding (MARSIS) measures ground receivers the TEC between the Martian • MIT Haystack provides calibrated surface and Mars Express TEC measurements • Mars Express has an inclination - Available from 1999 onward of 86.9˚ and a period of 7h, - Includes all open ground and allowing observations of all space-based sources locations and times - Specified with a 1˚ latitude by 1˚ • TEC is available for solar zenith longitude resolution with error estimates angles (SZA) greater than 75˚ Picardi and Sorge (2000), In: Proc. SPIE. Eighth International Rideout and Coster (2006) doi:10.1007/s10291-006-0029-5, 2006. Conference on Ground Penetrating Radar, vol. 4084, pp. 624–629. -
Morphology and Dynamics of the Venus Atmosphere at the Cloud Top Level As Observed by the Venus Monitoring Camera
Morphology and dynamics of the Venus atmosphere at the cloud top level as observed by the Venus Monitoring Camera Von der Fakultät für Elektrotechnik, Informationstechnik, Physik der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr.rer.nat.) genehmigte Dissertation von Richard Moissl aus Grünstadt Bibliografische Information Der Deutschen Bibliothek Die Deutsche Bibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über http://dnb.ddb.de abrufbar. 1. Referentin oder Referent: Prof. Dr. Jürgen Blum 2. Referentin oder Referent: Dr. Horst-Uwe Keller eingereicht am: 24. April 2008 mündliche Prüfung (Disputation) am: 9. Juli 2008 ISBN 978-3-936586-86-2 Copernicus Publications, Katlenburg-Lindau Druck: Schaltungsdienst Lange, Berlin Printed in Germany Contents Summary 7 1 Introduction 9 1.1 Historical observations of Venus . .9 1.2 The atmosphere and climate of Venus . .9 1.2.1 Basic composition and structure of the Venus atmosphere . .9 1.2.2 The clouds of Venus . 11 1.2.3 Atmospheric dynamics at the cloud level . 12 1.3 Venus Express . 16 1.4 Goals and structure of the thesis . 19 2 The Venus Monitoring Camera experiment 21 2.1 Scientific objectives of the VMC in the context of this thesis . 21 2.1.1 UV Channel . 21 2.1.1.1 Morphology of the unknown UV absorber . 21 2.1.1.2 Atmospheric dynamics of the cloud tops . 21 2.1.2 The two IR channels . 22 2.1.2.1 Water vapor abundance and cloud opacity . 22 2.1.2.2 Surface and lower atmosphere . -
Solar Wind Fluence to the Lunar Surface
44th Lunar and Planetary Science Conference (2013) 2015.pdf SOLAR WIND FLUENCE TO THE LUNAR SURFACE. D. M. Hurley1,3, W. M. Farrell2,3, 1JHU Applied Phys- ics Laboratory ([email protected]), 2NASA Goddard Space Flight Center, 3NASA Lunar Science Institute. Monolayers delivered in one lunation Introduction: The unperturbed solar wind bom- 90 bards the dayside of the Moon with electrons, protons, 60 and heavier ions throughout most of a lunation. Ex- cept when the Moon is in the Earth’s magnetotail for a 30 few days each lunation, the solar wind (shocked solar 0 N. Latitude wind in the magnetosheath, and unshocked solar wind -30 beyond Earth’s bow shock) has access to the dayside -60 surface of the Moon. Investigations of how the solar -90 wind could contribute to the composition and optical 0 90 180 270 360 properties of the lunar surface have a long history (e.g. E. Longitude [1-7]. Yet, it is instructive to revisit this issue and ex- Figure 2. The solar wind proton fluence as a function of amine the solar wind interaction piece by piece. selenographic position is shown in terms of fractions of Delivered Flux: The upper limit on the solar wind an equivalent monolayer of OH. The solid lines neglect thermal effects while the dashed lines include thermal as a potential source of OH can be established by as- effects. suming all of the incident solar wind protons are re- tained in the lunar regolith. The quiescent solar wind is implanted 3He as a resource guide. Fig. 2 shows the variable, but has density, n, of ~5 p+cm-3 and velocity, calculated fluence for one lunation assuming a spheri- v, of ~350 km s-1. -
The Observational Analemma
On times and shadows: the observational analemma Alejandro Gangui IAFE/Conicet and Universidad de Buenos Aires, Argentina Cecilia Lastra Instituto de Investigaciones CEFIEC, Universidad de Buenos Aires, Argentina Fernando Karaseur Instituto de Investigaciones CEFIEC, Universidad de Buenos Aires, Argentina The observation that the shadows of objects change during the course of the day and also for a fixed time during a year led curious minds to realize that the Sun could be used as a timekeeper. However, the daily motion of the Sun has some subtleties, for example, with regards to the precise time at which it crosses the meridian near noon. When the Sun is on the meridian, a clock is used to ascertain this time and a vertical stick determines the angle the Sun is above the horizon. These two measurements lead to the construction of a diagram (called an analemma) as an extremely useful resource for the teaching of astronomy. In this paper we report on the construction of this diagram from roughly weekly observations during more than a year. PACS: 01.40.-d, 01.40.ek, 95.10.-a Introduction Since early times, astronomers and makers of sundials have had the concept of a "mean Sun". They imagined a fictitious Sun that would always cross the celestial meridian (which is the arc joining both celestial poles through the observer's zenith) at intervals of exactly 24 hours. This may seem odd to many of us today, as we are all acquainted with the fact that one day -namely, the time it takes the Sun to cross the meridian twice- is in fact 24 hours and there is no need to invent any new Sun. -
HOW to BE CREATIVE with DIRECTIONAL LIGHTING and PORTRAITURE Quick Guide Written by Ludmila Borošová
Photzy HOW TO BE CREATIVE WITH DIRECTIONAL LIGHTING AND PORTRAITURE Quick Guide Written by Ludmila Borošová HOW TO BE CREATIVE WITH DIRECTIONAL LIGHTING AND PORTRAITURE // © PHOTZY.COM 1 One of the common things we often hear professional Today, we’ll cover the following: photographers say is, “If you are a professional, you avoid shooting at noon.” It is partially true, because experienced • Reasons why photographers avoid shooting in photographers usually customize their schedule in order directional lighting to increase their chances of getting a type of light they • Tips before, during, and after a photoshoot for prefer. That is, usually a soft, beautiful light achieved achieving better outcomes in directional lighting by the golden hour near sunrise or sunset hours. I can’t Recommended Reading: If you’re interested in blame them – I’m one of them, preferring to work in learning more about light and how you can use it to my comfortable space of soft light, no harsh shadows, improve your photography, grab a copy of Photzy’s and beautiful “bokeh.” But what really does bring you bestselling premium guide: Understanding Light Book a step closer to becoming a professional? Being able to Two. shoot amazing pictures regardless of lighting conditions? Adapting to new and uncomfortable situations? The answer is yes, but first of all, you have to seek them. HOW TO BE CREATIVE WITH DIRECTIONAL LIGHTING AND PORTRAITURE // © PHOTZY.COM 2 WHY DO PHOTOGRAPHERS PREFER GOLDEN HOUR LIGHT AND AVOID SHOOTING AT NOON? There are various reasons why this has been the trend over the past years, and it is still a preferred time of day for the majority. -
Astrocalc4r: Software to Calculate Solar Zenith Angle
Northeast Fisheries Science Center Reference Document 11-14 AstroCalc4R: Software to Calculate Solar Zenith Angle; Time at sunrise, Local Noon, and Sunset; and Photosynthetically Available Radiation Based on Date, Time, and Location by Larry Jacobson, Alan Seaver, and Jiashen Tang August 2011 Recent Issues in This Series 10-15 Bluefish 2010 Stock Assessment Update, by GR Shepherd and J Nieland. July 2010. 10-16 Stock Assessment of Scup for 2010, by M Terceiro. July 2010. 10-17 50th Northeast Regional Stock Assessment Workshop (50th SAW) Assessment Report, by Northeast Fisheries Science Center. August 2010. 10-18 An Updated Spatial Pattern Analysis for the Gulf of Maine-Georges Bank Atlantic Herring Complex During 1963-2009, by JJ Deroba. August 2010. 10-19 International Workshop on Bioextractive Technologies for Nutrient Remediation Summary Report, by JM Rose, M Tedesco, GH Wikfors, C Yarish. August 2010. 10-20 Northeast Fisheries Science Center publications, reports, abstracts, and web documents for calendar year 2009, by A Toran. September 2010. 10-21 12th Flatfish Biology Conference 2010 Program and Abstracts, by Conference Steering Committee. October 2010. 10-22 Update on Harbor Porpoise Take Reduction Plan Monitoring Initiatives: Compliance and Consequential Bycatch Rates from June 2008 through May 2009, by CD Orphanides. November 2010. 11-01 51st Northeast Regional Stock Assessment Workshop (51st SAW): Assessment Summary Report, by Northeast Fisheries Science Center. January 2011. 11-02 51st Northeast Regional Stock Assessment Workshop (51st SAW): Assessment Report, by Northeast Fisheries Science Center. March 2011. 11-03 Preliminary Summer 2010 Regional Abundance Estimate of Loggerhead Turtles (Caretta caretta) in Northwestern Atlantic Ocean Continental Shelf Waters, by the Northeast Fisheries Science Center and the Southeast Fisheries Science Center. -
Mission Concept for a Satellite Mission to Test Special Relativity
Mission Concept for a Satellite Mission to Test Special Relativity VOLKAN ANADOL Space Engineering, masters level 2016 Luleå University of Technology Department of Computer Science, Electrical and Space Engineering LULEÅ UNIVERSITY of TECHNOLOGY Master Thesis SpaceMaster Mission Concept for a Satellite Mission to Test Special Relativity Supervisors: Author : Dr. Thilo Schuldt Volkan Anadol Dr. Norman Gürlebeck Examiner : Assoc. Prof. Thomas Kuhn September 29, 2016 Abstract In 1905 Albert Einstein developed the theory of Special Relativity. This theory describes the relation between space and time and revolutionized the understanding of the universe. While the concept is generally accepted new experimental setups are constantly being developed to challenge the theory, but so far no contradictions have been found. One of the postulates Einsteins theory of Relativity is based on states that the speed of light in vac- uum is the highest possible velocity. Furthermore, it is demanded that the speed of light is indepen- dent of any chosen frame of reference. If an experiment would find a contradiction of these demands, the theory as such would have to be revised. To challenge the constancy of the speed of light the so- called Kennedy Thorndike experiment has been developed. A possible setup to conduct a Kennedy Thorndike experiment consists of comparing two independent clocks. Likewise experiments have been executed in laboratory environments. Within the scope of this work, the orbital requirements for the first space-based Kennedy Thorndike experiment called BOOST will be investigated. BOOST consists of an iodine clock, which serves as a time reference, and an optical cavity, which serves as a length reference. -
Your Guide to Better Beach Photography by Sarah Vaughn
Your Guide to Better Beach Photography by Sarah Vaughn Shooting at the beach: your kids & clients Tips for full sun, back light & much more The beach and photography is a match made in heaven, with deep blue sky, cotton ball clouds, azure sea, and children laughing and playing in the golden sand. But it’s also one of the most challenging places to shoot. Have you ever tried to take pictures of your children or clients at the beach only to be confronted with full sun, blown hot spots, glare from the water, harsh shadows and lots of messy, sandy people? Beach photography is tricky, for sure. But with a few tips, techniques and practice, there are few locations that can yield as beautiful backdrops and happy, joy-filled subjects. My own love-hate relationship with sun-filled beach photos comes from living on an island in the Indian Ocean for many years. With no sand dunes or structures to filter the light, I learned to navigate beach photography through trial and error. And though a flash and reflector can be your best friend - I’ve chosen today to focus on tips that anyone can use, even if you’ve left your flash at home or couldn’t fit that reflector in your beach bag. Yours, Sarah Vaughn When to shoot First off, not all sun is created equal. When you are at the beach with nothing to block the light, choosing the right time of day is even more important. If you are shooting a family session at the beach, you will likely have control over when and where you schedule it and can select the best conditions for the job. -
Orbit Design Marcelo Suárez
Orbit Design Marcelo Suárez 6th Science Meeting; Seattle, WA, USA 19-21 July 2010 Orbit Design Requirements The following Science Requirements provided drivers for Orbit Design: ¾ Global Coverage: the entire extent (100%) of the ice-free ocean surface to at least ±80° latitude should be observed. ¾ Swath shall be at least 300 km with gaps between the footprints within a swath not exceeding 50 km on average. ¾ Temporal Coverage: In order to provide monthly accurate salinity measurements, grid point should be visited at least 8 times per month (counting both ascending and descending passes) ¾ Radiometer Geometry: Zenith angle of the Sun on the footprint should be greater than 90° (in shadow) to the extent possible. ¾ Instruments should operate in the 600 +100/-50 km altitude range. ¾ Orbit shall have a repeat pattern of less than or equal to 9 days maintained within ± 20 km Orbit Design - Suárez 2of 12 6th Science Meeting; Seattle, WA, USA 19-21 July 2010 Orbit Design The Aquarius/SAC-D Mission Orbit is defined by the following parameters and tolerances: • Mean Semi-major axis: 7028.871 km +/- 1.5 km • Mean Eccentricity: 0.0012 +/− 0.0001 • Mean Inclination: 98.0126 deg + / - 0.001 degrees • Mean Local Mean Time of Ascending Node: 18:00 0 /+5 min • Mean Argument of perigee: 90 deg +/- 5 deg Remarks : Equatorial altitude: 657 km +/- 1.5 km Ground-track Repeat: 7 days Ground-track Separation at Equator: 389 km Ground-track kept within +/- 20 km of nominal along equator Sun-Synchronous Orbit Orbit Design - Suárez 3of 12 6th Science Meeting; Seattle, WA, USA 19-21 July 2010 Leap-frog sampling pattern 389 Km 2724 Km 4 Day 0-7 5 1 2 6 Day 0-7 3 4of 12 19-21 July 2010 Orbit Design - Suárez Seattle, WA, USA 6th Science Meeting; Eclipses Because of the changing position of the Sun with respect to the orbital plane there are yearly Eclipse seasons which take place between May and August at southern latitudes.