The historical method of precise orbit determination is a dynamic approach. However, with the improvement of GPS tracking data and associated tracking networks, two newer methods have been developed: reduced-dynamic and kinematic. In addition to orbit determination, alternative methods of gravity field recovery have been developed using kinematic orbits which do not rely on any force modeling. However, one significant drawback of kinematic orbits is that they lack any velocity or acceleration information. These have to be derived numerically. Based on the results of this thesis, the Savitzky-Golay filter, without using a remove-restore procedure, is recommended for deriving kinematic velocities of the GRACE mission. In addition, the numerical differentiation methods are tested to see how well accurately they represent the satellite's acceleration for all three orbit types. Finally, with the kinematic orbits properly reconstructed, the results can also be compared to dynamic and reduced-dynamic orbits through K-Band Ranging residuals. / text

The twin Gravity Recovery and Climate Experiment (GRACE) satellites were successfully launched on March 17, 2002. The mission goal is to make significant improvement in current measurements of the Earth’s gravity field. The satellites are linked by a K-band ranging system, which measures the range change due to the gravitational and non-gravitational accelerations. The non-gravitational accelerations can be obtained by transforming the accelerometer measurements into the inertial frame of reference based on the star camera observations, and will be used to separate gravitational effects in the range changes. However, the accelerometer’s proof mass offset from the center of mass of the spacecraft must be minimized and the misalignment between star camera frame and accelerometer frame must be known accurately in order to reduce the accelerometer data error. In addition, the phase center of the K-band horn must be known to make antenna offset corrections to the range and range change data. The objective of the center of mass calibration is to determine the proof mass offset, and then, to use the center of mass trim assembly mechanism to eliminate this offset. The main purpose of the K-band ranging system calibration is to determine the phase center of the K-band antenna, which will be used to adjust the satellite attitude orientations and make the antenna offset corrections to the K-band ranging system phase measurements. Furthermore, this calibration allows the misalignment between star camera frame and accelerometer frame to be determined. The calibration maneuvers have been designed for the real mission. Estimation algorithms have been developed and complete simulations have been performed. Finally, the real calibration data have been processed. Analysis shows that the proof mass offset has been determined better than the requirement value of 0.1 mm and trimmed well below this value. The boresight error of the K-band horn’s phase center has been determined better than 0.3 mrad and the resultant antenna offset correction error of range and range rate will be much less than the system resolution (10[mu]m ,1[mu]m/ s) and the frame misalignment parameters have been determined better than (0.04o ,1[delta] ) . Overall, the goal of calibrations has been successfully achieved. / text

No description available.

Grace Paley's fiction has suffered from being labeled as (alternately) post-modernist and feminist. There is a critical assumption that post-modernist and feminist works are plotless because they are nontraditional. Plot has been defined in Aristotelian terms, and those terms have colored the thinking of critics who attempt to discuss non-Aristotelian plots. Ironically, even feminist critics who are keenly aware that language is empowerment use the traditional language of literary criticism to describe nontraditional plots.As a result, post-modernist and feminist narrative modes are seen as fragmentary. This judgment often as not is simply a reaction to the Aristotelian emphasis on the unity of plot. Literary "unity" is not, however, an antonym for "fragmentation." To assume that nontraditional works such as Paley's are fragmented is to ignore the stories. The opposite of literary unity is not fragmentation, but amalgamation.Similar critical assumptions are that Paley's work is plotless and carries no implicit meaning. Careful readings of the stories in question lay both of these assumptions to rest. The point here is to make reading and understanding the stories the first priority. To use the stories as merely a chance to apply theory is to do both theory and the stories a disservice. / Department of English

The environmental crisis of the twentieth century challenges Christianity to articulate a theology adequate to support a viable environmental ethic. This dissertation finds such a theology in the thought of American Lutheran theologian, Joseph Sittler. Sittler characterizes his thought, not as a "theology of nature," but as an "incarnation theology applied to nature." Because of the christological and sacramental emphases in his theology, the dissertation demonstrates that the roots for Sittler's environmental concerns are to be found in the Christology and eucharistic theology of the sixteenth century reformer, Martin Luther. But in order to compensate for the emphasis in sixteenth century reformation theology on redemption as the salvation of the individual from sin, Sittler also retrieves the theology of the second century theologian, Irenaeus of Lyons. In his own fight against gnosticism, Irenaeus demonstrates continuity between Creation and redemption as acts of the same God. Thus Sittler develops a "theology for earth," emphasizing the continuity of nature and grace and, using concepts drawn from literature, music, architecture, painting, and modern physics, articulating an "ontology of communion" in which human beings recognize the presence of God in their own participation in the raw materials and processes of the world.

Thesis (Th. M.)--Calvin Theological Seminary, 1988. / Includes bibliographical references (leaves 197-206).

Thesis (M.A.)--Ohio University, August, 2007. / Title from PDF t.p. Includes bibliographical references.

Project (M.A.R.)--Gordon-Conwell Theological Seminary, South Hamilton, MA, 2005. / Abstract and vita. Includes bibliographical references (leaf 52).

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (D. Min.)--Western Theological Seminary, 1994. / Includes abstract and curriculum vitae. Includes bibliographical references (leaves 58-59).