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.
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Showing 1 to 20 of 24 for “"Arecibo"”.
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Improved observational programs for the Arecibo ionospheric observatory
… data taking programs have been completed for the Arecibo Ionospheric Observatory. One will cover the 200-2000 km range and measure electron number densities, temperatures and composition with a time resolution of 25 min. at low altitudes and 1 and one-fourth hrs. at high altitudes. The other …
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Full-profile inversion of ionospheric radar data from Arecibo observatory
… uses a variant of the same approach applied to Arecibo long pulse ISR data collected during the September 2016 topside F-region ISR data campaign. Our description provides details of forward model construction, choice of spline parameters, the optimizing algorithm, and an independent electron …
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Inversion of Arecibo incoherent scatter radar coded long pulse backscatter spectra
Incoherent scatter radar (ISR) at Arecibo Observatory measures the scattering of electromagnetic waves from random density fluctuations of ionospheric plasma particles (electrons and ions). Information about particle temperatures, ion concentrations, and Doppler shifts caused by particle motions …
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Plasma line generation and spectral estimation from Arecibo Observatory radar data
… spectral measurements can be conducted at the Arecibo Observatory, one of the most important centers in the world for research in radio astronomy, planetary radar and terrestrial aeronomy [Altschuler, 2002]. Although ISR measurements have been routinely taken at Arecibo since the early 1960s, …
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Long-pulse incoherent scatter probing of the F-region ionosphere at Arecibo
… experiments probing the F-region ionosphere at Arecibo utilize three types of transmission envelopes having different range-mixing and error statistical models on their corresponding backscattered pulse returns. The binary-coded envelope with wide bandwidth (0.44 ms duration and 220 bauds) …
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Incoherent scatter radar detection of enhanced plasma line in ionospheric E-region over Arecibo
… radar (ISR) observation were conducted at the Arecibo Observatory from December 27, 2005 until January 3, 2006. From plasma line measurements that were taken during this radar campaign, we found that plasma line enhancement was quite frequently seen in the ionospheric E-region. We hypothesized …
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Lidar studies of sporadic sodium layers, gravity waves and density spectra in the mesopause and stratopause regions at Urbana and Arecibo
… observations of a sporadic E layer by the Arecibo 430 MHz incoherent scatter radar and a sporadic Na layer by the UIUC CEDAR Na lidar are presented. The high correlation between the altitude and abundance variation of the two layers is discussed.
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Intense spreading of radar echoes from ionospheric plasmas
… ionospheric plasma bubble was observed over Arecibo Observatory in Puerto Rico, inducing significant range spreading on ionograms. This phenomena may be explained by means of the E x B instability and gravitational Rayleigh-Taylor instability. A derivation of the dispersion relations for X …
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Could global warming affect space weather? : case studies of intense ionospheric plasma turbulence associated with natural heat sources
… ionospheric plasma turbulence over Arecibo on the nights of 22/23 and 23/24 July, 2006. Incoherent scatter measurements by Arecibo radar, airglow measurements using MIT PSFC's all-sky imaging system (ASIS), together with TEC measurements from GPS satellite network provide …
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Investigation of thermal filamentation instability over Gakona, Alaska
… in mid-latitude ionospheric plasmas during Arecibo, Puerto Rico heating experiments in 1997. The geometry of the kilometer-scale parallel plates predicted by thermal filamentation depends on the mode of the transmitted heater wave, as does the threshold to excite this instability. While …
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La Marginal: A Coastal Promenade Park
… for a coastal promenade park in the town of Arecibo, Puerto Rico. The proposal acts as a link between the town, the park and the coastal edge. The coastal promenade park is created as a connector, defined mostly by the concrete walls that resemble the coastal edge. The concrete walls are used …
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Near-optimal inversion of incoherent scatter radar measurements: coding schemes, processing techniques, and experiments
… coding scheme and inversion methodology using Arecibo incoherent scatter radar (ISR) to achieve efficient, and near-optimal estimates of the key ionospheric parameters. In particular, this work considers two aspects of the ISR inversion problem: (i) ISR lag estimates at individual altitudes, …
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Artificial heating of the lower ionosphere
… been heated in a controlled experiment at the Arecibo ionospheric Observatory. Deposition of energy from a 40 Mhz transmitter has approximately doubled the ambient electron temperature at an altitude of 80 km. Energy from the radio wave is deposited in the ionosphere as a result of collisions …
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Ion and electron temperatures in the topside ionosphere
… an analysis of incoherent-scatter data taken at Arecibo, Puerto Rico. Consideration of the energy balance equations gives the theoretical ion and electron temperatures. Two ions, 0+ and H+, are assumed to be the only ions present in the topside ionosphere. Experimental evidence shows that a third …
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Courting Serendipity: The Search for Transient Radio Signals
… Four planetary systems were observed at the Arecibo Observatory. In 15 hours of 327 MHz observations made over the course of nine days in July, 2004, no detections were made.
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An Application and Refinement of the Karst Disturbance Index through Evaluating Variability in Island Karst Disturbance in Puerto Rico
… for other areas. Application of the KDI in Arecibo, Puerto Rico, which is geographically isolated, and highly vulnerable due to its sensitive karst resources, provides an opportunity to test the index in an island setting. This research resulted in two KDI scores for the study area using …
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Tests of Gravity Theories with Pulsar Timing
… timing data from observing campaigns with the Arecibo and Effelsberg telescopes, we will present an update to previous gravity test results from the pulsar-white dwarf binary PSR J1738+0333 . We confirm the validity of General Relativity and set tighter constraints on the parameter space of …
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Excitation of Langmuir wave turbulence in high-frequency (HF) pump waves over Gakona, Alaska
… are compared to observations made at Arecibo, Puerto Rico and Tromso, Norway. Claims are also are supported by incoherent backscatter radar observations made at the HAARP facility in Gakona.
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The Galaxy Velocity Function from MIGHTEE-HI Early Science Data
… previous large-scale H I surveys, namely the Arecibo Legacy Fast ALFA (ALFALFA) survey and the H I Parkes All-Sky Survey (HIPASS). There is general agreement with the ALFALFA and HIPASS results, when taking linewidth broadening into account, given that the MIGHTEE-H I Early Science data is …
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