42 research outputs found
Fernerkundung fuer die Umweltueberwachung. T. 2 Beitraege. Stand und Entwicklungstendenzen
The 6th scientific conference of the series on 'State of the art and development trends of remote sensing' organised by the Central Institute for Geophysics was dedicated to the topical subject of 'Remote sensing in environmental monitoring'. The papers deal with the following subjects: New remote sensing systems for environmental monitoring, Sensing of contaminated areas and industrial environmental dangers, landscape and regional sensing, vegetation and forest state sensing. (HM)Die vom Zentralinstitut fuer Physik der Erde organisierte 6. Wissenschaftliche Konferenz der Reihe 'Stand und Entwicklungstendenzen der Fernerkundung' war dem aktuellen Thema 'Fernerkundung fuer die Umweltueberwachung' gewidmet. Die Vortraege, behandeln folgende Themen: 1. Neue Fernerkundungssysteme fuer die Umweltueberwachung, 2. Erkundung von Altlasten und industrielle Umweltgefaehrdungen, 3. Landschafts- und Regionalerkundungen und 4. Vegetation- sowie Waldzustandserkundungen. (HM)Available from TIB Hannover: RA 2879(118.2) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA) GmbH, Bonn (Germany)DEGerman
Die Einmessung der PRARE-Bodenstationen und der neuen SLR-Station im lokalen Netz auf dem Telegrafenberg Potsdam
Available from TIB Hannover: RR 6134(97-03) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Oceanic influence on the seasonal polar motion
Oceanic contributions to the seasonal wobbles of polar motion are evaluated using three different ocean circulation models: (a) the POCM (Parallel Ocean Climate Model); (b) the model by Ponte et al. (1998); (c) the model by Thomas and Suendermann (1998). The excitation ellipses are given at annual, semi-annual and thrice-yearly periods. These ellipse parameters are compared to differences: (excitation from observations) - (atmospheric part). The model by Ponte et al. nearly closes the balance. (orig.)SIGLEAvailable from TIB Hannover: RR 6134(99/10) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Atmospheric oceanic and hydrological contributions to seasonal variations in length of day
In our previous studies, the annual and semiannual residuals derived in the axial angular momentum budget of the solid Earth-atmosphere system reflected significant signals, which must be caused by additional excitation sources. Here, the contribution for the wind term from the atmospheric layer between the 10 hPa and 0.3 hPa levels to the seasonal variations in length of day (LOD) was still missing. Therefore, there is the need to extend the top level into the upper stratosphere up to 0.3 hPa. To investigate the missing wind effects at seasonal time scales, we use the axial atmospheric angular momentum (AAM) data derived for the 10-0.3 hPa layer from 1991 to 1997. Ocean current and mass distribution changes also induce detectable LOD variations. Axial oceanic angular momentum (OAM) functions as generated by oceanic general circulation models (GCMs), namely for the ECHAM3 and the MICOM models, are available from 1975 to 1994 and 1992 to 1994, respectively, to compute the oceanic contributions to LOD changes. Concerning the variations in hydrological angular momentum (HAM) as another excitation source, we use the estimates of the hydrological contribution by Chao and O'Connor (1988). Using the vector representation, we show to what extent the vectors achieve a balance in the global axial angular momentum budget on the seasonal time scales. (orig.)Available from TIB Hannover: RR 6134(2000,5) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Fernerkundung fuer die Umweltueberwachung Beitraege zur Konferenz
Available from TIB Hannover: RA2879(118,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Seasonal length-of-day changes and axial Atmospheric-Angular-Momentum oscillations in their temporal variability
Recently, effective Atmospheric-Angular-Momentum (AAM) functions as calculated from NCEP (formerly NMC) and NCAR Reanalyses have become available from 1968 to 1997. Concerning the wind terms, the top level in the atmosphere used here is 10 hPa. Compared with earlier NMC model versions, which incorporate wind fields up to 100 hPa since 1976 and up to 50 hPa since 1981, the reanalyses have produced improved data series over a longer period than before. The axial AAM component #chi#_3 is associated with changes in Length-Of-Day (LOD). Motivated by better quality and continuity of the series AAM (NCEP) Reanalysis, the problem of the seasonal imbalances in the solid Earth-atmosphere axial angular momentum budget is re-examined. To assess better the estimates of the annual and semiannual oscillations in LOD and AAM and of the residual oscillations derived as difference series between LOD and AAM, the series of LOD data from three analysis centers (IERS, GFZ, JPL) and of AAM data in terms of #chi#_3(W), #chi#_3(P) and #chi#_3(P+IB) from four meteorological centers (NCEP, JMA, ECMWF and UKMO) are used. The main analysis steps were removing gaps, filtering out the seasonal oscillations, calculating optimal estimates of the parameters of the oscillations and calculating the differences series between the LOD and AAM systems as well as the residuals in the axial angular momentum budget in the LOD-AAM systems. The results derived in the different systems show to which extent the variations reflect systematic differences and significant signals, respectively, which is important for future activities in this field. (orig.)Available from TIB Hannover: RR 6134(98/10) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Grundlagenforschung zur Entwicklung und Anwendung von Sensoren fuer die Erfassung und Weiterleitung seismischer Aktivitaeten Abschlussbericht
Up to now there are no seismic sensors for long time high temperature applications available because of the failure of electronics by temperatures above 450 Kelvin. The aim of this project is to search for sensor principles suitable for seismic measurements in extreme environments especially in deep boreholes. A first test model of a mechanical oscillator of such a seismic sensor was developed and investigated. The dynamical behaviour of the oscillator is simulated by use of the finite element program ANSYS. A fiber optic Fabry-Perot-Interferometer represents a suitable principle for single transforming. The project was finished untimely because the institute is closed down. (orig.)Gegenwaertig sind keine seismischen Sensoren, die fuer den Einsatz bei hohen Temperaturen ueber lange Zeitraeume geeignet sind, verfuegbar. Der wesentliche Grund dafuer liegt im Versagen der Elektronik bei Temperaturen ueber 450 Grad Kelvin. Das Ziel dieses Projektes ist die Suche nach Prinziploesungen fuer seismische Sensoren fuer den Einsatz unter extremen aeusseren Bedingungen, speziell in tiefen Bohrloechern. Ein erstes Muster des mechanischen Empfaengers eines solchen seismischen Sensors wurde entwickelt und getestet. Das dynamische Verhalten des mechanischen Schwingers wird mit Hilfe des FEM-Programms ANSYS simuliert. Als geeignetes Prinzip fuer die Signalwandlung erweist sich ein faseroptisches Fabry-Perot-Interferometer. Das Projekt musste vorzeitig auf Grund der Schliessung des Instituts beendet werden. (orig.)Available from TIB Hannover: F94B0327+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman
Die Sicherung der alten Messpfeiler und ihre Rekonstruktion auf dem Dach von Gebaeude A17
Available from TIB Hannover: RR 6134(97-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman