The Search for Extrasolar Planets by the Means of High Precision Astrometry with the Dual-Feed Interferometer PRIMA

Several hundred extrasolar planets have been discovered until today. The most commonly applied detection methods are indirect and therefore typically limited in determining the whole set of the orbital parameters and in characterizing the specific planets. Among these, astrometry serves as an important complementary technique, as the orbital inclination and the planet's true mass can be derived from the two-dimensional measurements of the host star's reflex motion due to the presence of a companion. The VLTI's dual-feed interferometer PRIMA has been developed to provide high precision differential astrometry at the level of tens of microarcseconds, by which Saturn-like planets around nearby stars would become detectable. This is accomplished by simultaneous phase-referenced fringe tracking on two sources within the isoplanatic angle. Within this thesis the instrument's overall performance during commissioning is examined. Stable fringe tracking on both sources is generally achieved, and the effect of phase referencing is evident. However, phase jumps during the observations are reported, which might be due to phase shift offsets between the spatially modulated reference signals, from which the phases are recovered. These are investigated. An analysis of the discrepancy between the achieved astrometric precisuins on short and long time scales reveals hidden but evident systematic errors

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion