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Full-Text Articles in Engineering
A Roughness Correction For Aquarius Ocean Brightness Temperature Using The Conae Microwave Radiometer, Yazan Hejazin
A Roughness Correction For Aquarius Ocean Brightness Temperature Using The Conae Microwave Radiometer, Yazan Hejazin
Electronic Theses and Dissertations
Aquarius/SAC-D is a joint NASA/CONAE (Argentine Space Agency) Earth Sciences satellite mission to measure global sea surface salinity (SSS), using an L-band radiometer that measures ocean brightness temperature (Tb). The application of L-band radiometry to retrieve SSS is a difficult task, and therefore, precise Tb corrections are necessary to obtain accurate measurements. One of the major error sources is the effect of ocean roughness that "warms" the ocean Tb. The Aquarius (AQ) instrument (L-band radiometer/scatterometer) baseline approach uses the radar scatterometer to provide this ocean roughness correction, through the correlation of radar backscatter with the excess ocean emissivity. In contrast, …
Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek
Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek
Electronic Theses and Dissertations
Forecasts of short term volcanic activity are generated using an event tree process that is driven by a set of empirical statistical models derived through logistic regression. Each of the logistic models are constructed from a sparse and geographically diverse dataset that was assembled from a collection of historic volcanic unrest episodes. The dataset consists of monitoring measurements (e.g. seismic), source modeling results, and historic eruption information. Incorporating this data into a single set of models provides a simple mechanism for simultaneously accounting for the geophysical changes occurring within the volcano and the historic behavior of analog volcanoes. A bootstrapping …
A Microwave Radiometer Roughness Correction Algorithm For Sea Surface Salinity Retrieval, Yazan Henry Hejazin
A Microwave Radiometer Roughness Correction Algorithm For Sea Surface Salinity Retrieval, Yazan Henry Hejazin
Electronic Theses and Dissertations
The Aquarius/SAC-D is an Earth Science remote sensing satellite mission to measure global Sea Surface Salinity (SSS) that is sponsored by the NASA and the Argentine Space Agency (CONAE). The prime remote sensor is the Aquarius (AQ) L-band radiometer/scatterometer, which measures the L-band emitted blackbody radiation (brightness temperature) from the ocean. The brightness temperature at L-band is proportional to the ocean salinity as well as a number of physical parameters including ocean surface wind speed. The salinity retrieval algorithm make corrections for all other parameters before retrieving salinity, and the greatest of these is the increased brightness temperature due to …
Engineering Evaluation Of Multi-Beam Satellite Antenna Boresight Pointing Using Land/Water Crossings, Catherine Susan May
Engineering Evaluation Of Multi-Beam Satellite Antenna Boresight Pointing Using Land/Water Crossings, Catherine Susan May
Electronic Theses and Dissertations
The Microwave Radiometer (MWR) on the Aquarius/SAC-D mission measures microwave radiation from earth and intervening atmosphere in terms of brightness temperature (Tb). It takes measurements in a push-broom fashion at K (23.8GHz) and Ka (36.5 GHz) band frequencies using two separate antenna systems, each producing eight antenna beams. Pre-launch knowledge of the alignment of these beams with respect to the space-craft is used to geolocate the antenna footprints on ground. As a part of MWR’s on-orbit engineering check-out, the verification of MWR’s pointing accuracy is discussed here. The technique used to assess MWR’s pointing involved comparing the radiometer image of …
An Improved Ocean Vector Winds Retrieval Approach Using C- And Ku-Band Scatterometer And Multi-Frequency Microwave Radiometer Measurements, Suleiman Odeh Alsweiss
An Improved Ocean Vector Winds Retrieval Approach Using C- And Ku-Band Scatterometer And Multi-Frequency Microwave Radiometer Measurements, Suleiman Odeh Alsweiss
Electronic Theses and Dissertations
This dissertation will specifically address the issue of improving the quality of satellite scatterometer retrieved ocean surface vector winds (OVW), especially in the presence of strong rain associated with tropical cyclones. A novel active/passive OVW retrieval algorithm is developed that corrects Ku-band scatterometer measurements for rain effects and then uses them to retrieve accurate OVW. The rain correction procedure makes use of independent information available from collocated multi-frequency passive microwave observations provided by a companion sensor and also from simultaneous C-band scatterometer measurements. The synergy of these active and passive measurements enables improved correction for rain effects, which enhances the …
An Improved Hurrican Wind Vector Retrieval Algorithm Using Sea Winds Scatterometer, Peth Laupattarakasem
An Improved Hurrican Wind Vector Retrieval Algorithm Using Sea Winds Scatterometer, Peth Laupattarakasem
Electronic Theses and Dissertations
Over the last three decades, microwave remote sensing has played a significant role in ocean surface wind measurement, and several scatterometer missions have flown in space since early 1990's. Although they have been extremely successful for measuring ocean surface winds with high accuracy for the vast majority of marine weather conditions, unfortunately, the conventional scatterometer cannot measure extreme winds condition such as hurricane. The SeaWinds scatterometer, onboard the QuikSCAT satellite is NASA's only operating scatterometer at present. Like its predecessors, it measures global ocean vector winds; however, for a number of reasons, the quality of the measurements in hurricanes are …
Hurricane Wind Retrieval Algorithm Development For An Airborne Conical Scanning Scatterometer, Santhosh Vasudevan
Hurricane Wind Retrieval Algorithm Development For An Airborne Conical Scanning Scatterometer, Santhosh Vasudevan
Electronic Theses and Dissertations
Reliable ocean wind vector measurements can be obtained using active microwave remote sensing (scatterometry) techniques. With the increase in the number of severe hurricanes making landfall in the United States, there is increased emphasis on operational monitoring of hurricane winds from aircraft. This thesis presents a data processing algorithm to provide real-time hurricane wind vector retrievals (wind speed and direction) from conically scanning airborne microwave scatterometer measurements of ocean surface backscatter. The algorithm is developed to best suit the specifications for the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division's airborne scatterometer Integrated Wind and Rain Airborne Profiler …
Raindrop Size Distribution Retrieval And Evaluation Using An S-Band Radar Profiler, Fang Fang
Raindrop Size Distribution Retrieval And Evaluation Using An S-Band Radar Profiler, Fang Fang
Electronic Theses and Dissertations
Vertical pointing Doppler radar profilers are used to explore the vertical structure of precipitation cloud systems and to provide validation information for use in weather research. In this thesis, a theoretical radar rain-backscatter model was developed to simulate profiler Doppler spectra as a function of assumed rain parameters, of which the raindrop size distribution (DSD) is the fundamental quantity used to describe the characteristics of rain. Also, profiler observations during stratiform rain are analyzed to retrieve the corresponding rain DSD’s. In particular, a gamma distribution model is introduced, which uses Rayleigh scattering portion of the Doppler velocity spectrum to estimate …