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THE ROLE OF RAIN IN POSTCLASSIC MAYA RELIGIOUS BELIEF
Title
THE ROLE OF RAIN IN POSTCLASSIC MAYA RELIGIOUS BELIEF.
Creator
Dao, Lillie, Barber, Sarah, University of Central Florida
Abstract / Description
The concept of religion and its practice within ancient societies across the world is a subject that has fascinated scientists for centuries. The pre-Columbian Maya codices, first-hand Postclassic hieroglyphic documents, have been examined by hundreds of anthropologists. Analysis of these books has led scientist to hypothesize that these manuscripts were vitally connected to the Maya Postclassic belief system. Understanding the central focus of a civilization's religion and how, why and under...
Show moreThe concept of religion and its practice within ancient societies across the world is a subject that has fascinated scientists for centuries. The pre-Columbian Maya codices, first-hand Postclassic hieroglyphic documents, have been examined by hundreds of anthropologists. Analysis of these books has led scientist to hypothesize that these manuscripts were vitally connected to the Maya Postclassic belief system. Understanding the central focus of a civilization's religion and how, why and under what circumstances the religion is practiced truly distinguishes them as a culture. The intent of this thesis is to examine the role of rain in Maya Postclassic religious belief. Through an examination of Postclassic Maya ethnographies, archaeological evidence and the Maya Dresden, Paris and Madrid codices, this thesis evaluates the major theme of rain that is threaded throughout the culture and religion of the Maya people. By cross referencing ethnohistoric, ethnographic and archaeological evidence, it is revealed that rain was a fundamental-part of Maya religious practice as: 1) a symbol of fertility, 2) a phenomenon that people actively sought to control through religious practice and 3) as a fundamental building block of the Maya universe, construed broadly to encompass both the natural and divine elements of the universe.
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Date Issued
2011
Identifier
CFH0004126, ucf:44886
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004126
DEVELOPMENT OF AN OCEANIC RAIN ACCUMULATION PRODUCT IN SUPPORT OF SEA SURFACE SALINITY MEASUREMENTS FROM AQUARIUS/SAC-D
Title
DEVELOPMENT OF AN OCEANIC RAIN ACCUMULATION PRODUCT IN SUPPORT OF SEA SURFACE SALINITY MEASUREMENTS FROM AQUARIUS/SAC-D.
Creator
Aslebagh, Shadi, Jones, W, Wahid, Parveen, Junek, William, University of Central Florida
Abstract / Description
Aquarius/SAC-D is a joint mission by National Aeronautics and Space Administration (NASA) and the Comision Nacional de Actividades Espaciales (CONAE), Argentine Space Agency. The satellite was launched in June 2011 and the prime remote sensing instrument is also named Aquarius (AQ). The main objective of this science program is to provide Sea Surface Salinity (SSS) maps of the global oceans every 7 days for understanding the Earth's hydrologic cycle and for assessing long-term global climate...
Show moreAquarius/SAC-D is a joint mission by National Aeronautics and Space Administration (NASA) and the Comision Nacional de Actividades Espaciales (CONAE), Argentine Space Agency. The satellite was launched in June 2011 and the prime remote sensing instrument is also named Aquarius (AQ). The main objective of this science program is to provide Sea Surface Salinity (SSS) maps of the global oceans every 7 days for understanding the Earth's hydrologic cycle and for assessing long-term global climate change.The Aquarius instrument was built jointly by NASA's Goddard Space Flight Center and the Jet Propulsion Laboratory. It is an active/passive L-band remote sensor that measures ocean brightness temperature (Tb) and radar backscatter, and these quantities are used to infer sea surface salinity.Other environmental parameters (e.g., sea surface temperature, wind speed and rain) also affect the microwave emitted radiance or brightness temperature. The SSS geophysical retrieval algorithm considers all these environmental parameters and makes the Tb corrections before retrieving SSS. Instantaneous rainfall can cause increase roughness that raises the ocean surface Tb. Further short term rain accumulation can produce a fresh water lens that floats on the ocean surface and dilutes the surface salinity.This thesis presents results of a study to develop an oceanic rain accumulation (RA) product that may be valuable to remote sensing engineers and algorithm developers and Aquarius scientists. The use of this RA product, along with in situ ocean salinity measurements from buoys, may be used to mitigate the effects of rain on the SSS retrieval.
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Date Issued
2013
Identifier
CFE0004647, ucf:49906
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0004647
OCEANIC RAIN IDENTIFICATION USING MULTIFRACTAL ANALYSIS OF QUIKSCAT SIGMA-0
Title
OCEANIC RAIN IDENTIFICATION USING MULTIFRACTAL ANALYSIS OF QUIKSCAT SIGMA-0.
Creator
Torsekar, Vasud, Kasparis, Takis, University of Central Florida
Abstract / Description
The presence of rain over oceans interferes with the measurement of sea surface wind speed and direction from the Sea Winds scatterometer and as a result wind measurements contain biases in rain regions. In past research at the Central Florida Remote Sensing Lab, it has been observed that rain has multi-fractal behavior. In this report we present an algorithm to detect the presence of rain so that rain regions are flagged. The forward and aft views of the horizontal polarization σ0 are...
Show moreThe presence of rain over oceans interferes with the measurement of sea surface wind speed and direction from the Sea Winds scatterometer and as a result wind measurements contain biases in rain regions. In past research at the Central Florida Remote Sensing Lab, it has been observed that rain has multi-fractal behavior. In this report we present an algorithm to detect the presence of rain so that rain regions are flagged. The forward and aft views of the horizontal polarization σ0 are used for the extraction of textural information with the help of multi-fractals. A single negated multi-fractal exponent is computed to discriminate between wind and rain. Pixels with exponent value above a threshold are classified as rain pixels and those that do not meet the threshold are further examined with the help of correlation of the multi-fractal exponent within a predefined neighborhood of individual pixels. It was observed that the rain has less correlation within a neighborhood compared to wind. This property is utilized for reactivation of the pixels that fall below a certain threshold of correlation. An advantage of the algorithm is that it requires no training, that is, once a threshold is set, it does not need any further adjustments. Validation results are presented through comparison with the Tropical Rainfall Measurement Mission Microwave Imager (TMI) 2A12 rain retrieval product for one whole day. The results show that the algorithm is efficient in suppressing non-rain (wind) pixels. Also algorithm deficiencies are discussed, for high wind speed regions. Comparisons with other proposed approaches will also be presented.
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Date Issued
2005
Identifier
CFE0000671, ucf:46498
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000671
Investigation of the effect of rain on sea surface salinity
Title
Investigation of the effect of rain on sea surface salinity.
Creator
Santos Garcia, Andrea, Jones, W Linwood, Mikhael, Wasfy, Wahid, Parveen, Junek, William, Asher, William, Wilheit, Thomas, University of Central Florida
Abstract / Description
The Aquarius/SAC-D mission provided Sea Surface Salinity (SSS), globally over the ocean, for almost 4 years. As a member of the AQ/SAC-D Cal/Val team, the Central Florida Remote Sensing Laboratory has analyzed these salinity measurements in the presence of precipitation and has noted the high correlation between the spatial patterns of reduced SSS and the spatial distribution of rain. It was determined that this is the result of a cause and effect relation, and not SSS measurement errors....
Show moreThe Aquarius/SAC-D mission provided Sea Surface Salinity (SSS), globally over the ocean, for almost 4 years. As a member of the AQ/SAC-D Cal/Val team, the Central Florida Remote Sensing Laboratory has analyzed these salinity measurements in the presence of precipitation and has noted the high correlation between the spatial patterns of reduced SSS and the spatial distribution of rain. It was determined that this is the result of a cause and effect relation, and not SSS measurement errors. Thus, it is important to understand these salinity changes due to seawater dilution by rain and the associated near-surface salinity strati?cation. This research addresses the effects of rainfall on the Aquarius (AQ) SSS retrieval using a macro-scale Rain Impact Model (RIM). This model, based on the superposition of a one-dimension eddy diffusion (turbulent diffusion) model, relates SSS to depth, rainfall accumulation and time since rain. To identify instantaneous and prior rainfall accumulations, a Rain Accumulation product was developed. This product, based on the NOAA CMORPH precipitation data set, provides the rainfall history for 24 hours prior to the satellite observation time, which is integrated over each AQ IFOV. In this research results of the RIM validation are presented by comparing AQ and SMOS measured and RIM simulated SSS. The results show the high cross correlation for these comparisons and also with the corresponding SSS anomalies relative to HYCOM.
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Date Issued
2016
Identifier
CFE0006175, ucf:51133
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006175
HURRICANE WIND SPEED AND RAIN RATE RETRIEVAL ALGORITHM FOR THE STEPPED FREQUENCY MICROWAVE RADIOMETER
Title
HURRICANE WIND SPEED AND RAIN RATE RETRIEVAL ALGORITHM FOR THE STEPPED FREQUENCY MICROWAVE RADIOMETER.
Creator
Amarin, Ruba, Jones, Linwood, University of Central Florida
Abstract / Description
This thesis presents the development and validation of the Hurricane Imaging Retrieval Algorithm (HIRA) for the measurement of oceanic surface wind speed and rain rate in hurricanes. The HIRA is designed to process airborne microwave brightness temperatures from the NOAA, Stepped Frequency Microwave Radiometer (SFMR), which routinely collects data during NOAA hurricane hunter aircraft flights. SFMR measures wind speeds and rain rates at nadir only, but HIRA will soon be integrated with an...
Show moreThis thesis presents the development and validation of the Hurricane Imaging Retrieval Algorithm (HIRA) for the measurement of oceanic surface wind speed and rain rate in hurricanes. The HIRA is designed to process airborne microwave brightness temperatures from the NOAA, Stepped Frequency Microwave Radiometer (SFMR), which routinely collects data during NOAA hurricane hunter aircraft flights. SFMR measures wind speeds and rain rates at nadir only, but HIRA will soon be integrated with an improved surface wind speed model for expanded utilization with next generation microwave hurricane imagers, such as the Hurricane Imaging Radiometer (HIRad). HIRad will expand the nadir only measurements of SFMR to allow the measurement of hurricane surface winds and rain over a wide swath Results for the validation of HIRA retrievals are presented using SFMR brightness temperature data for 22 aircraft flights in 5 hurricanes during 2003-2005. Direct comparisons with the standard NOAA SFMR empirical algorithm provided excellent results for wind speeds up to 70 m/s. and rain rates up to 50 mm/hr.
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Date Issued
2006
Identifier
CFE0001313, ucf:47024
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001313
Hurricane Imaging Radiometer (HIRAD) tropical rainfall retrievals
Title
Hurricane Imaging Radiometer (HIRAD) tropical rainfall retrievals.
Creator
Alasgah, Abdusalam, Jones, W Linwood, Wahid, Parveen, Mikhael, Wasfy, Gong, Xun, Zec, Josko, University of Central Florida
Abstract / Description
The Hurricane Imaging Radiometer (HIRAD) is an airborne passive microwave remote sensor, developed to measure wind speed and rain rate in hurricanes. This dissertation concerns the development of a signal processing algorithm to infer tropical rainfall from HIRAD radiance (brightness temperature, Tb) measurements.The basis of the rain rate retrieval algorithm is an improved forward microwave radiative transfer model (RTM) that incorporates the HIRAD multi-antenna-beam geometry, and uses semi...
Show moreThe Hurricane Imaging Radiometer (HIRAD) is an airborne passive microwave remote sensor, developed to measure wind speed and rain rate in hurricanes. This dissertation concerns the development of a signal processing algorithm to infer tropical rainfall from HIRAD radiance (brightness temperature, Tb) measurements.The basis of the rain rate retrieval algorithm is an improved forward microwave radiative transfer model (RTM) that incorporates the HIRAD multi-antenna-beam geometry, and uses semi-empirical coefficients derived from an airborne experiment that occurred in the Gulf of Mexico off Tampa Bay in 2013. During this flight, HIRAD observed a squall line of thunderstorms simultaneously with an airborne meteorological radar (High Altitude Wind and Rain Profiler, HIWRAP), located on the same airplane. Also, ground based NEXRAD radars from the National Weather Service (located at Tampa and Tallahassee) provided high resolution simultaneous rain rate measurements.Using NEXRAD rainfall as the surface truth input to the HIRAD RTM, empirical rain microwave absorption coefficients were tuned to match the measured brightness temperatures. Also, the collocated HIWRAP radar reflectivity (dBZ) measurements were cross correlated with NEXRAD to derive the empirical HIWRAP radar reflectivity to rain rate relationship. Finally, the HIRAD measured Tbs were input to the HIRAD rain retrieval algorithm to derive estimates of rain rate, which were validated using the independent HIWRAP measurements of rain rate.
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Date Issued
2019
Identifier
CFE0007775, ucf:52379
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007775
RAIN RATE ALGORITHM FOR AQUARIUS/SAC-D MICROWAVE RADIOMETER
Title
RAIN RATE ALGORITHM FOR AQUARIUS/SAC-D MICROWAVE RADIOMETER.
Creator
Menzerotolo, Rosa, Jones, W. Linwood, University of Central Florida
Abstract / Description
Microwave radiometers are used to measure blackbody microwave emissions emitted by natural targets. Radiative transfer theory provides a well founded physical relationship between the atmosphere and surface geophysical parameters and the brightness temperature measured by these radiometers. The atmospheric brightness temperature is proportional to the integral of the microwave absorption of water vapor, oxygen, and liquid water between the top of the atmosphere and the surface. Inverse...
Show moreMicrowave radiometers are used to measure blackbody microwave emissions emitted by natural targets. Radiative transfer theory provides a well founded physical relationship between the atmosphere and surface geophysical parameters and the brightness temperature measured by these radiometers. The atmospheric brightness temperature is proportional to the integral of the microwave absorption of water vapor, oxygen, and liquid water between the top of the atmosphere and the surface. Inverse radiative transfer models use to retrieve the water vapor, cloud liquid and oxygen content in the atmosphere are very well known; however, the retrieval of rain rate in the atmosphere is still a challenge. This project presents a theoretical basis for the rain rate retrieval algorithm, which will be implemented in the Aquarius/SAC-D Microwave Radiometer (MWR). This algorithm was developed based on the radiative transfer model theory for a single layer atmosphere using four WindSat channels. Transmissivity due to liquid water (rain and cloud liquid water) is retrieved from the four channel brightness temperatures, and a statistical regression is performed to relate the rain rate, rain physical temperature and rain height to the liquid water transmissivities at 24 GHz and 37 GHz. Empirical validation results are presented using the WindSat radiometer observations.
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Date Issued
2011
Identifier
CFE0003571, ucf:48911
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0003571
AN IMPROVED MICROWAVE RADIATIVE TRANSFER MODEL FOR OCEAN EMISSIVITY AT HURRICANE FORCE SURFACE WIND SPEED
Title
AN IMPROVED MICROWAVE RADIATIVE TRANSFER MODEL FOR OCEAN EMISSIVITY AT HURRICANE FORCE SURFACE WIND SPEED.
Creator
EL-Nimri, Salem, Jones, Linwood, University of Central Florida
Abstract / Description
An electromagnetic model for predicting the microwave blackbody emission from the ocean surface under the forcing of strong surface winds in hurricanes is being developed. This ocean emissivity model will be incorporated into a larger radiative transfer model used to infer ocean surface wind speed and rain rate in hurricanes from remotely sensed radiometric brightness temperature. The model development is based on measurements obtained with the Stepped Frequency Microwave Radiometer (SFMR),...
Show moreAn electromagnetic model for predicting the microwave blackbody emission from the ocean surface under the forcing of strong surface winds in hurricanes is being developed. This ocean emissivity model will be incorporated into a larger radiative transfer model used to infer ocean surface wind speed and rain rate in hurricanes from remotely sensed radiometric brightness temperature. The model development is based on measurements obtained with the Stepped Frequency Microwave Radiometer (SFMR), which routinely flys on the National Oceanic and Atmospheric Administration's hurricane hunter aircraft. This thesis presents the methods used in the wind speed model development and validation results for wind speeds up to 70 m/sec. The ocean emissivity model relates changes in measured C-band radiometric brightness temperatures to physical changes in the ocean surface. These surface modifications are the result of the drag of surface winds that roughen the sea surface, produce waves, and create white caps and foam from the breaking waves. SFMR brightness temperature measurements from hurricane flights and independent measurements of surface wind speed are used to define empirical relationships between microwave brightness temperature and surface wind speed. The wind speed model employs statistical regression techniques to develop a physics-based ocean emissivity model dependent on geophysical parameters, such as wind speed and sea surface temperature, and observational parameters, such as electromagnetic frequency, electromagnetic polarization, and incidence angle.
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Date Issued
2006
Identifier
CFE0001312, ucf:47019
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001312