ALBERT

Description: The commemorative publication of the 150-year anniversary of the foundation of the Geodetic Institute Karlsruhe (GIK) presents the historical overview of the development of the GIK. Current research results are presented and innovations are shown.

Description: In dem vorliegenden Buch wird die Ausgleichung nach dem Total-Least-Squares-Prinzip vorgestellt und auf geodätische Problemstellungen angewandt. Total Least Squares ist ein relativ junges Verfahren im Bereich der Parameterschätzung.Für Geodäten stellt sich die Frage, ob sich Total Least Squares auch bei gängigen Problemstellungen der Geodäsie verwenden lässt und ob sich durch die Ausgleichung nach Total Least Squares im Vergleich zu den traditionellen Verfahren neue Erkenntnisse gewinnen lassen. Um die Arbeitsweise dieses Schätzers nachvollziehen zu können, werden zunächst genau die mathematischen Grundlagen vorgestellt, die in diesem Kontext eine Rolle spielen. Auf Basis dieser Grundlagen wird sowohl die klassische Berechnung einer Ausgleichung nach TLS als auch die eines gemischten TLS-LS-Problems erklärt. Weiterhin wird aufgezeigt, wie ein TLS-Problem in ein Gauß-Helmert-Problem umgewandelt werden kann, um den Kreis der möglichen Anwendungen zu erweitern. Eine kurze Zusammenfassung der wichtigsten konventionellen Modelle erleichtert die Einordnung von TLS, die auch die Entwicklung des mehrdimensionalen Beobachtungstests für Gauß-Helmert-Modelle beinhaltet. An unterschiedlichen Fallbeispielen wird untersucht, wie die Voraussetzungen für die Anwendung von TLS geschaffen werden können und welche Vorteile sich durch die Ausgleichung nach TLS ergeben.

Description: Dieser Band enthält 64 Artikel zu Themengebieten der Geophysik, veröffentlicht durch die Deutsche Geophysikalische Gesellschaft in den Jahren 1976 und 1977.

Description: Inhaltsverzeichnis: Journal of Geophysics 42 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0009.pdf"〉Short-Time Variations of Solar Particle Fluxes during the August 1972 Events〈/a〉〈br〉 (Kremser, G., Riedler, W., Kirsch, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0011.pdf"〉Auroral Lyman-Alpha Emission〈/a〉〈br〉 (Dose, V., Schmocker, U., Sele, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0012.pdf"〉The Gravity Field of Northeastern Iceland〈/a〉〈br〉 (Schleusener, A., Torge, W., Drewes, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0016.pdf"〉Parabolic Field Dependence of Kinks Occurring in the Logarithmic Time Plots of Viscous Magnetization〈/a〉〈br〉 (Markert, H., Heller, F., Steigenberger, N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0018.pdf"〉Postulated Rotation of Corsica not Confirmed by New Palaeomagnetic Data〈/a〉〈br〉 (Storetvedt, K. M., Petersen, N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0020.pdf"〉Magnetic Anomalies of the African Red Sea Shelf and Their Implications for the Anomalies of Atlantic Continental Margin〈/a〉〈br〉 (Roeser, H. A.)〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0021.pdf"〉Self-Reversal above Room Temperature due to N-Type Magnetization in Basalt〈/a〉〈br〉 (Schult, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0022.pdf"〉Further Utilization of the Fluxgate Magnetometer in the Palaeomagnetic Laboratory〈/a〉〈br〉 (Hummervoll, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0023.pdf"〉Note on the Reliability of Subjective Processing of Geomagnetic Pulsation-Records in the Range Pc 2–Pc 5〈/a〉〈br〉 (Korschunow, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0024.pdf"〉Die Gesteinsradioaktivität und ihr Einfluß auf das Temperaturfeld in der kontinentalen Kruste〈/a〉〈br〉 (Rybach, L.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0025.pdf"〉A Lithospheric Seismic Profile in Britain〈/a〉〈br〉 (Kaminski, W., Bamford, D., Faber, S., Jacob, B., Nunn, K., Prodehl, C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0026.pdf"〉Rayleigh Channel Waves for the In-Seam Seismic Detection of Discontinuities〈/a〉〈br〉 (Dresen, L., Freystätter, S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0028.pdf"〉Ultrasonic Modelling of a Moving Source〈/a〉〈br〉 (Behle, A., Rohde, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0029.pdf"〉Propagation of Love-Type Waves in Heterogeneous Elastic Layers〈/a〉〈br〉 (Biswas, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0030.pdf"〉Representation and Interpretation of Resistivity Mapping Data in Groundwater Prospecting in Zambia〈/a〉〈br〉 (Töpfer, K. D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0032.pdf"〉The Iranian Long Period Array (ILPA)〈/a〉〈br〉 (Akasheh, B., Eshghi, I., Soltanian, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0033.pdf"〉Appearance of the Atmospheric Scatter Field during a Solar Eclipse〈/a〉〈br〉 (Gerharz, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0034.pdf"〉Technique for Simultaneous Observation of Gravity and Vertical Gradient Data〈/a〉〈br〉 (Thyssen-Bornemisza, S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0035.pdf"〉Modern Standards for Gravity Surveys〈/a〉〈br〉 (Morelli, C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0036.pdf"〉Book Reviews〈/a〉〈br〉 (Schick, R., Rummel, F.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0037.pdf"〉Tunneling of Low-Frequency Waves through the Subcrustal Lithosphere〈/a〉〈br〉 (Fuchs, K., Schulz, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0041.pdf"〉Computation of Reflection Coefficients for Layered Media〈/a〉〈br〉 (Kind, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0042.pdf"〉The Seismic Broadband Recording and Data Processing System FBV/DPS and Its Seismological Applications〈/a〉〈br〉 (Plešinger, A., Horálek, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0045.pdf"〉Intermediate Aseismicity of the Andean Subduction Zone and Recent Andesitic Volcanism〈/a〉〈br〉 (Hanuš, V., Vaněk, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0046.pdf"〉Provisional Seismicity Map of the Republic of Zambia and Its Preliminary Interpretation〈/a〉〈br〉 (Töpfer, K. D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0047.pdf"〉Goethermal Models of the Crust and Uppermost Mantle of the Fennoscandian Shield on South Norway and the Danish Embayment〈/a〉〈br〉 (Balling, N. P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0048.pdf"〉Spatial Characteristics of Giant Pulsations〈/a〉〈br〉 (Hillebrand, O.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0050.pdf"〉Latitude-Dependent Waves and Impulse-Produced Waves〈/a〉〈br〉 (Lanzerotti, L. J., Hasegawa, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0051.pdf"〉Study of the Spatial Variation of the Magnetic Field Intensity on North-South Profiles in Iran in Comparison with the IGRF Model of 1970〈/a〉〈br〉 (Guya, N. H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0053.pdf"〉Seismische Oberflächenwellen〈/a〉〈br〉 (Seidl, D., Müller, S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0055.pdf"〉Crustal Structure of the Central Aegean Sea and the Island of Evia and Crete, Greece, Obtained by Refractional Seismic Experiments〈/a〉〈br〉 (Makris, J., Vees, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0057.pdf"〉Fault-Plane Solution of the Earthquake in Northern Italy, 6 May 1976, and Implications for the Tectonics of the Eastern Alps〈/a〉〈br〉 (Müller, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0058.pdf"〉Pseudo-Single-Domain Effects and Single-Domain Multidomain Transition in Natural Pyrrhotite Deduced from Domain Structure Observations〈/a〉〈br〉 (Soffel, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0059.pdf"〉The Diurnal Variation of the Electron Density of the Mid-Latitude Ionospheric D-Region Deduced from VLF-Measurements〈/a〉〈br〉 (Schäfer, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0061.pdf"〉A Detailed Investigation of the Canadian Cordillera Geomagnetic Transition Anomaly〈/a〉〈br〉 (Dragert, H., Clarke, G. K. C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0065.pdf"〉Magnetotelluric Investigation of a Nearly Circular Saltdome in North Germany〈/a〉〈br〉 (Breymann, U.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0066.pdf"〉Comments on: Postulated Rotation of Corsica not Confirmed by New Palaeomagnetic Data〈/a〉〈br〉 (Westphal, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0067.pdf"〉Reply〈/a〉〈br〉 (Storetvedt, K. M., Petersen, N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0068.pdf"〉Structure of Lunar Impact Craters from Gravity Models〈/a〉〈br〉 (Janle, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0069.pdf"〉A Refined Crustal Model and the Isostatic State of the Scandinavian Blue Road Area〈/a〉〈br〉 (Goldflam, St., Hirschleber, H. B., Janler, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0070.pdf"〉Earth-Flattening Approximation for Body Waves Derived from Geometric Ray Theory – Improvements, Corrections and Range of Applicability〈/a〉〈br〉 (Müller, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0071.pdf"〉On the Variation of Kp at Sector Boundaries〈/a〉〈br〉 (Schreiber, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0072.pdf"〉Probleme bei der Untersuchung von räumlich und zeitlich veränderlichen Medien, dargestellt am Beispiel der Ionosphäre〈/a〉〈br〉 (Dieminger, W., Hartmann, G. K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0073.pdf"〉Heat Flow Map of the Bohemian Massif〈/a〉〈br〉 (Čermák, V.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0074.pdf"〉Palaeomagnetic and Rock Magnetic Investigations of Tertiary Volcanics in Northern Bavaria〈/a〉〈br〉 (Pohl, J., Soffel, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0078.pdf"〉Palaeomagnetism of Upper Jurassic Limestones from Southern Germany〈/a〉〈br〉 (Heller, F.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0079.pdf"〉The Maximum Entropy Approach to Inverse Problems〈/a〉〈br〉 (Rietsch, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0080.pdf"〉Electromagnetic Scale Model Experiments for the Coastline Effect of Geomagnetic Variations〈/a〉〈br〉 (Spitta, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0081.pdf"〉Model Studies on Redox Logging for Minerals〈/a〉〈br〉 (Roy, K. K., Baksi, S. S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0084.pdf"〉Modelling of the Ionosphere and Comparison of the Calculated and Observed Cosmic Radio Noise Absorption over Delhi〈/a〉〈br〉 (Sharma, M. C., Sarma, S. B. S. S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0086.pdf"〉Winter Anomaly in VHF Absorption Studies over Delhi〈/a〉〈br〉 (Sarma, S. B. S. S., Sharma, M. C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0089.pdf"〉In Memoriam Hermann Reich〈/a〉〈br〉 (Closs, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0094.pdf"〉Plasma Disturbances Caused by Helios in the Solar Wind〈/a〉 〈i〉Seiten 581-582 fehlen〈/i〉〈br〉 (Isensee, U.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0095.pdf"〉Radial Variation of the Interplanetary Magnetic Field Between 0.3 AU and 1.0 AU〈/a〉〈br〉 (Musmann, G., Neubauer, F. M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0096.pdf"〉Initial Results from the Helios-1 Search-Coil Magnetometer Experiment〈/a〉〈br〉 (Neubauer, F.M., Beinroth, H. J., Barnstorf, H., Dehmel, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0100.pdf"〉Cosmic Ray Measurements on Board Helios 1 from December 1974 to September 1975: Quiet Time Spectra, Radial Gradients, and Solar Events〈/a〉〈br〉 (Kunow, H., Witte, M., Wibberenz, G., Hempre, H., Mueller-Mellin, R., Green, G., Iwers, B., Fuckner, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0102.pdf"〉A Survey on Measurements of Medium Energy Protons and Electrons Obtained with the Particle Spectrometer E8 on Board of Helios〈/a〉〈br〉 (Keppler, E., Richter, A. K., Richter, K., Umlauft, G., Wilken, B., Williams, D. J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0105.pdf"〉Interaction of Low-Energy (〉80 keV) Protons with the January 6 and 8, 1975, Shock Waves: Helios-1 Observations〈/a〉〈br〉 (Richter, A. K., Keppler, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0107.pdf"〉Helios-1 Faraday Rotation Experiment: Results and Interpretations of the Solar Occultations in 1975〈/a〉〈br〉 (Volland, H., Bird, M. K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0109.pdf"〉Time Delay Occultation Data of the Helios Spacecrafts and Preliminary Analysis for Probing the Solar Corona〈/a〉〈br〉 (Edenhofer, P., Esposito, P. B., Hansen, R. T., Hansen, S. F., Lüneburg, E., Martin, W. L., Zygielbaum, A. I.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0111.pdf"〉Observatons of Zodiacal Light from Helios 1 and 2〈/a〉〈br〉 (Leinert, C., Pitz, E., Hanner, M., Link, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0112.pdf"〉Interpretation of the Optical Properties of Interplanetary Dust〈/a〉〈br〉 (Giese, R. H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0114.pdf"〉Micrometeoroid Data from the First Two Orbits of Helios 1〈/a〉〈br〉 (Grün, E., Fechtig, H., Kissel, J., Gammelin, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0116.pdf"〉Dynamical Effects on Circumsolar Dust Grains〈/a〉〈br〉 (Schwehm, G., Rohde, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1015067948_0042/LOG_0118.pdf"〉Micrometeoroid Orbits Observable by the Helios Micrometeoroid Detector (E 10)〈/a〉〈br〉 (Schmidt, K. D.)〈/li〉 〈/body〉 〈/html〉

Description: research

Description: DFG, SUB Göttingen

Description: INHALT: Rastogi, R. G.: Some Aspects of the F2 Region at Medium Latitudes of the Northern and Southern Hemispheres (S. 217); Freiburg, Ch. und W. Kertz: Anordnung von Stabmagneten zur Erzeugung homogener Feldbereiche (S. 227); Schulz, G.: Über ein Refraktionsproblem (S. 236); Haalck, F. und R. Schulze: Die mit dem UTM erreichbare Genauigkeit (S. 246); Brockamp, B.: Zur hypsographischen Kurve des Mondes (S. 271).

Description: research

Description: DFG, SUB Göttingen

Description: Inhalt: Bisztricsány, E.: On the problem of magnitude determination. ; Förtsch, O.: Ergebnisse seismischer Untersuchungen auf Gletschern der Ostalpen. ; Richter, G.: Über die Polarisation von SKS. ; Stefanescu, S. S.: Über die magnetische Wirkung einiger heterogener Medien in der elektrischen Bodenforschung. ; Vogler, G.: Die Grenzen der Anwendung von Erdungsmessern für Aufgaben in der angewandten Geophysik. ; Barta, G.: Über die Säkularbewegung des magnetischen Zentrums und der magnetischen Pole der Erde. ; Kertz, W.: Tages- und jahreszeitliche Variationen des erdmagnetischen äquatorialen Ringstromes. ; Schmucker, U.: Einige Ergebnisse der erdmagnetischen Tiefensondierung in Norddeutschland. ; Volland, H.: Modelle erdmagnetisch induzierter Ströme im inhomogenen Erdinnern. ; Frölich, F.: Zur magnetischen Stabilität von Erdkrustengesteinen. ; Luck, O.: Über den physikalischen Zustand der Materie im Erdinnern, ; Egyed, L. and Stegena, L.: Physical background of a dynamical Earth model, ; Dolezalek, H.: Die Problematik luftelektrisch-synoptischer Betrachtung. ; Israël, H.: Die luftelektrische Unruhe. ; Lucke, O. & Sparrer, H.: Die Gerätekonstante des elektrodynamischen Theodoliten des VEB WTBG, Berlin und die Vermessung der Primärspule mit dem Meßgerät des VEB Carl Zeiß, Jena. ; Reusche, H.-G.: Ein absoluter magnetischer Theodolit. ; Verö, J.: Über einige Ergebnisse des Erdstrom-Observatoriums bei Nagycenk in Ungarn. ; Schulze, R.: Die modernen Askania-Gravimeter: Erfahrungen, Verbesserungen und ihre Leistungsfähigkeit. ; Fanselau, G.: Über quadratische Mittelwerte des geomagnetischen Potentials. ; Grosse, S.: Ergebnisse gravimetrischer Regionalvermessungen im Westerzgebirge. ; Geier, S.: Die Berechnung von geoelektrischen Modellkurven bei beliebiger Elektroden-Anordnung auf horizontal geschichteten Medien. ; Neumenn, W.: Neue Untersuchung der irregulären geomagnetischen Anomalien bei Berggießhübel in Sachsen. ; Noßke, G. & Franke, R.: Einige Erfahrungen bei der geoelektrischen Kartierung von Mineralgängen, Spalten und Verschiebungen im Mittelgebirge. ; Rische, H.: Geschwindigkeitsbestimmung aus reflexionsseismischen Messungen bei Anwendung von Luftschüssen. ;

Description: research

Description: DGG, DFG, SUB Göttingen

Description: The quantum yield and reaction threshold for the photochemical dissociation of cyanoacetylene into a hydrogen atom and the cyanoethynyl radical have been determined. The quantum yield at 185 nm is approximately 0.09. The threshold is approximately 240 nm. Combination of this data with literature values shows that production of excited-state cyanoacetylene is the major primary process resulting from irradiation between 185 and 254 nm. Also determined are the relative rate constants for the abstraction of a hydrogen atom from hydrogen, methane, and ethane by the cyanoethynyl radical (k(H2):k(CH4):k(C2H6) = 1:9.3:63). Implications of these results for the proposal that hydrogen abstraction plays an important role in the conversion of methane to ethane and in the protection of unsaturated compounds from photoconsumption in the atmosphere of Titan are discussed.

Description: The atmospheric flow on Io is numerically computed in a flat 2-D axisymmetric geometry for a sublimation atmosphere on the trailing hemisphere subjected to plasma bombardment, UV heating, and IR cooling. Calculations are performed for subsolar vapor pressures of approximately 6.5 x 10(exp -3) Pa (approximately 3 x 10(exp 18) SO2/sq cm) and 6.8 x 10(exp -4) Pa (approximately 4 x 10(exp 17) SO2/sq cm); the latter approximates the vapor pressure of F. P. Fanale et al. (1982). The amount of plasma energy deposited in the atmosphere is 20% of the plasma flow energy due to corotation (J. A. Linker et al., 1988). It is found that plasma heating significantly inflates the upper atmosphere, increasing both the exobase altitude and the amount of surface covered by more than an exospheric column of gas. This in turn controls the supply of the Io plasma torus (M. A. McGrath and R. E. Johnson, 1987). The horizontal flow of mass and energy is also important in determining the exobase altitude; and it is shown that IR cooling can be important, although our use of the equilibrium, cool-to-space approximation for a pure SO2 gas (E. Lellouch et al., 1992) may overestimate this effect. The calculated exobase altitudes are somewhat lower than those suggested by McGrath and Johnson (1987) for supplying the torus, indicating the details of the plasma energy deposition and sputter ejection rate near the exobase, as well as the IR emission from this region need to be examined. In addition, the molecules sublimed (or sputtered) from the surface are transported to the exobase in times short compared to the molecular photodissociation time. Therefore, the exobase is dominated by molecular species and the exobase is supplied by a small region of the surface.

Description: Iapetus shows a greater hemispheric albedo asymmetry than any other body in the solar system. Hapke scattering theory and optical constants measured in the laboratory are used to identify possible compositions for the dark material on the leading hemisphere of Iapetus. The materials considered are poly-HCN, kerogen, Murchison organic residue, Titan tholin, ice tholin, and water ice. Three-component mixtures of these materials are modeled in intraparticle mixture of 25% poly-HCN, 10% Murchison residue, and 65% water ice is found to best fit the spectrum, albedo, and phase behavior of the dark material. The Murchison residue and/or water ice can be replaced by kerogen and ice tholin, respectively, and still produce very good fits. Areal and particle mixtures of poly-HCN, Titan tholin, and either ice tholin or Murchison residue are also possible models. Poly-HCN is a necessary component in almost all good models. The presence of poly-HCN can be further tested by high-resolution observations near 4.5 micrometers.

Description: A thermal model that can be easily adapted to craters of arbitrary shape is developed and applied to high-latitude impact craters on Mercury and the Moon, Chao Meng Fu crater at -87.5 deg L on Mercury, an unnamed bowl-shaped crater at 86.7 deg L on Mercury, and Peary crater at 88.6 deg L on the Moon. For an assumed input topography and grid of surface elements, the model computes for each element the irradiation from direct insolation and reflected and emitted radiation from other elements, taking into account shadowing by walls of the crater, partial obscuration of the solar disk near the poles and the diurnal, orbital, and seasonal cycles. Temperatures are computed over the surface grid as functions of depth and time from the surface to a specified depth and over the pertinent astronomical cycles, including the effects of direct and indirect surface irradiation, infrared radiation, heat conduction, and interior heating. Vapor fluxes and ice recession times are computed as functions of ice depth over the surface grid. Temperatures profiles, vapor fluxes, and ice recession times were computed for flat surfaces not associated with craters near the poles of Mercury and the Moon. It was found that water ice could have existed throughout geologic time within the maximum radar detection depth of recent observation of Mercury (J. K. Harmon and M. A. Slade, 1992, Science 258, 640-643) poleward of approximately 87 - 88 deg L on Mercury and poleward of approximately 73 deg L on the Moon. For Chao Meng Fu crater it was found that approximately 40% of the crater floor is permanently shadowed from direct solar insolation, while the remainder of the crater floor is periodically illuminated by a partially obscured Sun. Temperatures at the upper levels of the south wall can slightly exceed 550 K. Surface temperatures in the permanently shadowed region of the crater floor are under approximately 130 K, which could have allowed water ice to exist throughout geologic time within the radar detection depth of recent observation of Mercury. For small bowl-shaped crater on Mercury, it was found that most of the crater is permanently shadowed from direct solar radiation, except for a narrow semicircular band bordering the north rim. However, temperatures in the permanently shadowed region periodically reach a maximum near approximately 315 K due to efficient heating of the small crater by thermal emission and reflection from the small sunlit region, which periodically reaches temperatures exceeding 630 K. Water ice could not have existed throughout geologic time anywhere in this crater within the radar detection depth. For Peary crater on the Moon, the entire crater floor is permanently shadowed from direct solar insolation with maximum temperature under 120 K. The upper level of the north wall periodically reaches a maximum temperature near 310 K. The low temperatures on the crater floor would have allowed water ice to exist near the surface throughout geologic time, provided that the Moon's obliquity was always as low as it is at present.

Description: We examine the effects of the loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the past 3.8 billion years. Sputtering is capable of efficiently removing species from the upper atmosphere, including the light noble gases; nitrogen and oxygen are removed by photochemical processes as well. Due to diffusive separation (by mass) above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species, with the lighter mass being preferentially lost. For carbon and oxygen, this allows us to determine the size of nonatmospheric reservoirs which mix with the atmosphere; these reservoirs can be CO2 adsorbed in the regolith and H2O in the polar ice caps. We have constructed both simple analytical models and time-dependent models of the loss of volatiles from and supply to the martian atmosphere. Both argon and neon require continued replenishment from outgassing over geologic time. For argon, sputtering loss explains the fractionation of (Ar-36)/(Ar-38) without requiring a distinct epoch of hydrodynamic escape (although fractionation of Xe isotopes still requires very early hydrodynamic loss). For neon, the current (Ne-22)/(Ne-20) ratio represents a balance between loss to space and continued resupply from the interior; the similarity of the ratio to the terrestrial value is coincidental. For nitrogen, the loss by both sputtering and photochemical escape would produce a fractionation of (N-15)/(N-14) larger than observed; an early, thicker carbon dioxide atmosphere could mitigate the nitrogen loss and produce the observed fractionation, as could continued outgassing of juvenile nitorgen. Based on the isotopic constraints, the total amount of carbon dioxide lost over geologic time is probably on the order of tens of millibars rather than a substantial fraction of a bar. The total loss from solar-wind-induced sputtering and photochemical escape, therefore, does not seem able to explain the loss of a putative thick, early atmosphere withput requiring formation of extensive surface carbonate deposits or other nonatmospheric reservoirs for CO2.