Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 24 for “"orbital parameters"”.
-
MACPROP: A Revised Program for the Refinement of Satellite Orbital Parameters
Computer programs for the refinement of the orbital parameters of an artificial Earth satellite have been in use since 1957. One of the programs in current use is PROP. This program takes an initial estimate of the orbital parameters of an Earth satellite, together with observations of the …
-
A Feasibility Study for Using the ERAU Échelle Spectrograph to Improve Orbital Parameters of Spectroscopic Binary Systems
… many spectroscopic binaries have poorly defined orbital parameters as they have not been revisited with newer CCD technology since their first observations on photographic plates. This thesis examines the feasibility of using the high-resolution échelle spectrograph at Embry-Riddle Aeronautical …
-
Theoretical statistics of zero-age cataclysmic variables
… of the mass ratios and the distribution of the orbital periods in cataclysmic variables which are forming at the present time are calculated. These systems are referred to as ""zero-age cataclysmic variables"". The results show that 60% of the systems being formed contain helium white dwarfs and …
-
From CubeSats to constellations : systems design and performance analysis
… Our approach of performing a comprehensive orbital altitude and inclination reference point analysis for all subsystems allows us not only to evaluate trades between subsystems when designing a CubeSat that may be manifest in any low-Earth orbit, but the reference point analysis also …
-
Binary pulsars: evolution and fundamental physics
… spin frequency of the pulsar. Measurement of the orbital parameters and system geometry, and in particular the final system masses, thus provide important constraints for theories regarding binary evolution. We present results from an investigation of three binary pulsar systems. PSR J1802-2124 is …
-
The Effect of Orbital Forcing on the MJO’s Amplitude and Phase Speed
… represents the MJO, by changing Earth's orbital parameters. In response to the orbital forcing, boreal winter mean precipitation increases, consistent with a stronger Hadley circulation, and the mean lower-tropospheric westerly winds shift southward over the Indo-Pacific warm pool. The …
-
Observational constraints on the number, albedos, size, and impact hazards of the near-Earth asteroids
… near-Earth asteroids (NEAs) in terms of number, orbital parameters, reflectance spectra, albedos, diameters, and terrestrial and lunar collision rates. I estimate the size and shape of the NEA population using survey data from the Lincoln Near-Earth Asteroid Research project including more than …
-
Optimization of Disaggregated Space Systems Using the Disaggregated Integral Systems Concept Optimization Technology Methodology
… genetic algorithm to simultaneously optimize orbital parameters, payload parameters, and payload distribution for space systems. The solutions produced by the genetic algorithm are evaluated using cost estimation, coverage analysis, and spacecraft sizing modules. A set of validation cases are …
-
Compositional structure in the asteroid belt : results of a spectroscopic survey
… identified as clusters of objects having similar orbital parameters. The targeted region, encompassing the heliocentric distance range of 2.690 to 2.815 AU, contains 14 families that had been previously identified, based on numerous analyses of orbital distributions in this region of the;1 main …
-
Origin and Properties of Elliptical Galaxies in a Hierarchical Universe
… simulations of merging galaxies were tested. Orbital parameters of the merging galaxies are derived self-consistently from large scale N-body simulations, showing that the commonly used parameters are in agreement, but resemble just a small fraction of the possible parameter space. Most of the …
-
Optical and near infrared observations of accretion processes in galactic compact objects
… The observations are used to refine the binary parameters of several Low Mass X-ray Binaries, and to better understand the accretion processes in these systems. Accretion is essential in the formation of stars, planets and solar systems yet remains poorly understood. In this thesis, we present …
-
Continuous gravitational wave searches from neutron stars and exotic sources in ground-based interferometric data
… strategies: targeted searches, where source parameters should be perfectly constrained; narrowband searches, where source position is well constrained but rotational parameters not; and all-sky searches, which scan broad parameter spaces to find unknown sources. Specific attention is given to …
-
Resonance studies of artificial earth satellites
… For such satellites the perturbations of the orbital elements close to resonance are analysed to derive lumped harmonic coefficients. The orbital parameters of 1984-106A have been determined at 43 epochs, during which time the satellite was close to 14th order resonance. Analysis of the …
-
Exploring gravity
… provide insightful constraints on the MBHs' parameters. These could elucidate the formation history of the MBHs and, by association, their host galaxies. The Galactic centre is the most promising source. Its event rate is determined by the stellar distribution surrounding the MBH; the rate is …
-
Innovative water tracers and water isotopes enhance Antarctic research with climate models
… the magnitude of warming when only forced by orbital parameters and greenhouse gas concentrations during that period. Much of the warming can be reproduced by a climate model HadCM3 with a 3000-year freshwater forcing over the North Atlantic. These results highlight the importance of transient …
-
Using Nd Isotopes to understand changes in continental weathering flux in Mid-Pennsylvanian (Desmoinesian) carbonate cycles
… deposits indicates that changes in Earth's orbital parameters are one of the main drivers of climate change on the 104-105 yr time scales, however understanding the relationships between climate change on coeval marine and continental deposits is difficult due to post-depositional erosion …
-
A Feasibility Study On The Implementation Of Satellite-To-Satellite Tracking Around A Small Near-Earth Object
… GRACE and GRAIL missions to establish a range of orbital parameters that can be used to execute a SST mission around a small NEO. Preliminary mission requirements for data collection and orbital correction maneuvers are also established. Additionally, the data are used to determine whether or not …
-
An Investigation Of Climate Patterns On Earth-Like Planets Using The NASA GISS Global Climate Model II
… greenhouse gas emissions trends, planetary orbital parameters, and solar irradiance variations. It is found that the EdGCM interface to the GCM-II 3-D climate model is capable of studying climate patterns on hypothetical Earth-like planets, with some limitations involved. Studying extreme …
-
Effects of starspots activity on optical and near infrared observations of planetary transits
… and the derivations of planetary and stellar parameters. Surface brightness inhomogeneities, such as starspots or bright faculae, on star disc have an intrinsic dependence on wavelength and thus on the stellar colours. The colour dependence of stellar activity may significantly influence the …
-
SALT and TESS monitoring of central stars of planetary nebulae
… CSs and develop constraints to permissible orbital parameters. The High Resolution Spectrograph (HRS) of the Southern African Large Telescope (SALT) was used to collect échelle spectroscopic data over 3 years and The Exoplanet Survey Satellite (TESS) was used to obtain photometric data for …
Page 1 of 2