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Radar

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Full-Text Articles in Physical Sciences and Mathematics

Estimating Polarization Purity With Noise, Alex Kostinski, Dan Kestner, Jothiram Vivekanandan Mar 2024

Estimating Polarization Purity With Noise, Alex Kostinski, Dan Kestner, Jothiram Vivekanandan

Michigan Tech Publications, Part 2

We formulate a problem of estimating and monitoring mismatch (unwanted departure from orthogonality) of two ostensibly orthogonal polarization channels in a fully polarimetric general device such as a polarimetric weather radar. A statistical approach is proposed by using thermal noise or, more generally, a 'polarimetric noise' class of sources. The suitable noise class of distributions is shown to be rooted in the complex multivariate Gaussian probability density function (pdf), the latter possessing a uniform pdf on the Poincare sphere (PS), with a probability measure given by a fractional surface area. To that end, we develop a parameter to estimate polarization …

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On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke Jan 2024

On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke

CCPO Publications

Recent studies found that on long time scales there are often unexplained opposite trends in sea level variability between the upper and lower Chesapeake Bay (CB). Therefore, daily sea level and temperature records were analyzed in two locations, Norfolk in the southern CB and Baltimore in the northern CB; surface currents from Coastal Ocean Dynamics Application Radar (CODAR) near the mouth of CB were also analyzed to examine connections between the CB and the Atlantic Ocean. The observations in the bay were compared with daily Atlantic Meridional Overturning Circulation (AMOC) observations during 2005–2021. Empirical Mode Decomposition (EMD) analysis was used …

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A Method For Calculating Lateral Surface Area Of Bistatic Radar Beam Overlap, James I. Murray, Fredrick A. Jenet Jul 2023

A Method For Calculating Lateral Surface Area Of Bistatic Radar Beam Overlap, James I. Murray, Fredrick A. Jenet

Physics and Astronomy Faculty Publications and Presentations

It has been shown that bistatic radars using radio telescopes as receivers can be used to increase the sensitivity of orbital debris measurements over traditional terrestrial monostatic radar. A method to calculate the lateral surface area of a bistatic radar is needed to evaluate the efficacy of a proposed bistatic radar configuration for orbital debris measurements. For over three decades, models of the orbital debris (OD) environment in low Earth orbit (LEO) have been developed to assess the risk posed by OD to spacecraft. While terrestrial radar measures debris 3 mm and larger and in situ measurements provide data for …

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Radar Signatures In Tropical Cyclone Tornadic And Nontornadic Supercells, Michaela Wood May 2023

Radar Signatures In Tropical Cyclone Tornadic And Nontornadic Supercells, Michaela Wood

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Tropical cyclones (TCs) contain highly-sheared environments that are conducive for supercell thunderstorms. These TC supercells sometimes produce tornadoes, often with little warning. Given the often-close proximity of tornadic and nontornadic TC supercells, environments may not be well-distinguished, pointing to the potential value of radar observations. In this study, dual-polarimetric radar signatures of a sample of TC supercells are examined in the context of known supercell structure and microphysics. Tornadic and nontornadic TC supercells are compared with their midlatitude counterparts, and the environments and characteristic structure of these storms are shown to be notably different. An attempt is made to distinguish …

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Relative Importance Of Radar Variables For Nowcasting Heavy Rainfall: A Machine Learning Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos Dec 2022

Relative Importance Of Radar Variables For Nowcasting Heavy Rainfall: A Machine Learning Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos

Institute for ECHO Articles and Research

Highly short-term forecasting, or nowcasting, of heavy rainfall due to rapidly evolving mesoscale convective systems (MCSs) is particularly challenging for traditional numerical weather prediction models. To overcome such a challenge, a growing number of studies have shown significant advantages of using machine learning (ML) modeling techniques with remote sensing data, especially weather radar data, for high-resolution rainfall nowcasting. To improve ML model performance, it is essential first and foremost to quantify the importance of radar variables and identify pertinent predictors of rainfall that can also be associated with domain knowledge. In this study, a set of MCS types consisting of …

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Differentiating Fissure-Fed Lava Flow Types And Facies Using Radar And Lidar: An Example From The 2014–2015 Holuhraun Lava Flow-Field, Gavin Douglas Tolometti, Catherine D. Neish, Christopher W. Hamilton, Gordon R. Osinski, Antero Kukko, Joana R.C. Voigt Jun 2022

Differentiating Fissure-Fed Lava Flow Types And Facies Using Radar And Lidar: An Example From The 2014–2015 Holuhraun Lava Flow-Field, Gavin Douglas Tolometti, Catherine D. Neish, Christopher W. Hamilton, Gordon R. Osinski, Antero Kukko, Joana R.C. Voigt

Earth Sciences Publications

Distinguishing between lava types and facies using remote sensing data is important for interpreting the emplacement history of lava flow-fields on Earth and other planetary bodies. Lava facies typically include a mixture of lava types and record the collective emplacement history of material preserved at a particular location. We seek to determine if lava facies in the 2014–2015 Holuhraun lava flow-field are discernible using radar roughness analysis. Furthermore, we also seek to distinguish between lava types using high resolution Light Detection and Ranging (LiDAR) data. We extracted circular polarization ratios (CPR) from the Uninhabited Aerial Vehicle Synthetic Aperture Radar and …

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Detecting The Presence Of Electronic Devices In Smart Homes Using Harmonic Radar, Beatrice Perez, Gregory Mazzaro, Timothy J. Pierson, David Kotz Jan 2022

Detecting The Presence Of Electronic Devices In Smart Homes Using Harmonic Radar, Beatrice Perez, Gregory Mazzaro, Timothy J. Pierson, David Kotz

Dartmouth Scholarship

Data about users is collected constantly by phones, cameras, Internet websites, and others. The advent of so-called ‘Smart Things' now enable ever-more sensitive data to be collected inside that most private of spaces: the home. The first step in helping users regain control of their information (inside their home) is to alert them to the presence of potentially unwanted electronics. In this paper, we present a system that could help homeowners (or home dwellers) find electronic devices in their living space. Specifically, we demonstrate the use of harmonic radars (sometimes called nonlinear junction detectors), which have also been used in …

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In Situ Determination Of Dry And Wet Snow Permittivity: Improving Equations For Low Frequency Radar Applications, Ryan Webb, Adrian Marziliano, Daniel Mcgrath, Randall Bonnell, Tate G. Meehan, Carrie Vuyovich, Hans-Peter Marshall Nov 2021

In Situ Determination Of Dry And Wet Snow Permittivity: Improving Equations For Low Frequency Radar Applications, Ryan Webb, Adrian Marziliano, Daniel Mcgrath, Randall Bonnell, Tate G. Meehan, Carrie Vuyovich, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Extensive efforts have been made to observe the accumulation and melting of seasonal snow. However, making accurate observations of snow water equivalent (SWE) at global scales is challenging. Active radar systems show promise, provided the dielectric properties of the snowpack are accurately constrained. The dielectric constant (k) determines the velocity of a radar wave through snow, which is a critical component of time-of-flight radar techniques such as ground penetrating radar and interferometric synthetic aperture radar (InSAR). However, equations used to estimate k have been validated only for specific conditions with limited in situ validation for seasonal snow applications. …

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Bioscatter Transport By Tropical Cyclones: Insights From 10 Years In The Atlantic Basin, Matthew S. Van Den Broeke Jan 2021

Bioscatter Transport By Tropical Cyclones: Insights From 10 Years In The Atlantic Basin, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Tropical cyclones (TCs) can transport birds and insects near their center of circulation. In this study, we examined the maximum altitude, area and density of the radar-derived bioscatter signature across a set of 42 TC centers of circulation sampled from 2011 to 2020. All TC events contained at least one time when a bioscatter signature was present. More intense hurricanes with closed eyes typically had taller and denser bioscatter signatures, and sometimes larger areas dominated by bioscatter. This indicated a larger number of organisms within the circulation of more intense hurricanes, supporting the speculation that those storms were most likely …

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Interpretations Of Lava Flow Properties From Radar Remote Sensing Data, Gavin Douglas Tolometti, Catherine Neish, Gordon R. Osinski, Scott S. Hughes, Shannon E. Kobs-Nawotniak Oct 2020

Interpretations Of Lava Flow Properties From Radar Remote Sensing Data, Gavin Douglas Tolometti, Catherine Neish, Gordon R. Osinski, Scott S. Hughes, Shannon E. Kobs-Nawotniak

Earth Sciences Publications

The surface morphology and roughness of a lava flow provides insight on its lava properties and emplacement processes. This is essential information for understanding the eruption history of lava fields, and magmatic processes beneath the surface of Earth and other planetary bodies such as the Moon. The surface morphology is influenced by lava properties such as viscosity, temperature, composition, and rate of shear. In this work, we seek to understand how we can interpret the emplacement processes and lava properties of lava flows using remote sensing data. Craters of the Moon (COTM) National Monument and Preserve in Idaho hosts a …

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A Polarimetric Radar Analysis Of Cold- And Warm-Based Supercells, Timothy J. Gunkel Mar 2020

A Polarimetric Radar Analysis Of Cold- And Warm-Based Supercells, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Polarimetric analyses of supercell thunderstorms have been increasingly common within the past decade, since operational polarimetric radar data became available in 2013. Although polarimetric signatures within supercell thunderstorms are well known, few have investigated variability in these signatures in differing environments. Polarimetric signatures can provide vital information regarding the microphysical characteristics and processes in supercell thunderstorms. Specific polarimetric signatures of interest are the differential reflectivity (ZDR) column, the low-level polarimetrically inferred hail core, and the ZDR arc. These signatures provide information regarding updraft characteristics, hailfall characteristics, and size sorting processes in the storm- relative inflow. Previous studies …

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The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew V.D. Broeke, Timothy J. Gunkel Jan 2020

The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew V.D. Broeke, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Faculty Publications

Seasonal bird migration occurs on large spatial scales and is influenced by many factors including weather conditions. Weather can include thunderstorms, which may force migrants to land or cause them to reroute a migration path. In this study, a sample of isolated thunderstorms was analyzed from the domains of three weather radars in the central United States to test hypotheses regarding the influence of thunderstorms on the distribution of migrants. Migrating bird density was often reduced in the wake of storms, and this wake reduction was typically more pronounced for larger, more intense and faster- moving storms, particularly in eastern …

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The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew S. Van Den Broeke, Timothy J. Gunkel Jan 2020

The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew S. Van Den Broeke, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Faculty Publications

Seasonal bird migration occurs on large spatial scales and is influenced by many factors including weather conditions. Weather can include thunderstorms, which may force migrants to land or cause them to reroute a migration path. In this study, a sample of isolated thunderstorms was analyzed from the domains of three weather radars in the central United States to test hypotheses regarding the influence of thunderstorms on the distribution of migrants. Migrating bird density was often reduced in the wake of storms, and this wake reduction was typically more pronounced for larger, more intense and faster- moving storms, particularly in eastern …

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Melissa: System Description And Spectral Features Of Pre- And Post-Midnight F-Region Echoes, Fabiano S. Rodrigues, Weijia Zhan, Marco A. Milla, B. G. Fejer, Eurico R. De Paula, Acacio C. Neto, Angela M. Santos, Inez S. Batista Nov 2019

Melissa: System Description And Spectral Features Of Pre- And Post-Midnight F-Region Echoes, Fabiano S. Rodrigues, Weijia Zhan, Marco A. Milla, B. G. Fejer, Eurico R. De Paula, Acacio C. Neto, Angela M. Santos, Inez S. Batista

All Physics Faculty Publications

Most of the low‐latitude ionospheric radar observations in South America come from the Jicamarca Radio Observatory, located in the western longitude sector (∼75°W). The deployment of the 30 MHz FAPESP‐Clemson‐INPE (FCI) coherent backscatter radar in the magnetic equatorial site of São Luis, Brazil, in 2001 allowed observations to be made in the eastern sector (∼45°W). However, despite being operational for several years (2001–2012), FCI only made observations during daytime and pre‐midnight hours, with a few exceptions. Here, we describe an upgraded system that replaced the FCI radar and present results of full‐night F‐region observations. This radar is referred to …

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Seastar: A Mission To Study Ocean Submesoscale Dynamics And Small-Scale Atmosphere-Ocean Processes In Coastal, Shelf And Polar Seas, Christine Gommenginger, Bertrand Chapron, Andy Hogg, Christian Buckingham, Baylor Fox-Kemper, Leif Eriksson, Francois Soulat, Clement Ubelmann, Francisco Ocampo-Torres, Bruno Buongiorno Nardelli, David Griffin, Paco Lopez-Dekker, Per Knudsen, Ole Andersen, Lars Stenseng, Neil Stapleton, William Perrie, Nelson Violante-Carvalho, Johannes Schulz-Stellenfleth, David Woolf, Jordi Isern-Fontanet, Fabrice Ardhuin, Patrice Klein, Alexis Mouche, Ananda Pascual, Xavier Capet, Daniele Hauser, Ad Stoffelen, Rosemary Morrow, Lotfi Aouf, Øyvind Breivik, Lee-Leung Fu, Johnny A. Johannessen, Yevgeny Aksenov, Lucy Bricheno, Joel Hirschi, Adrien C. H. Martin, Adrian P. Martin, George Nurser, Jeff Polton, Judith Wolf, Harald Johnsen, Alexander Soloviev, Gregg A. Jacobs, Fabrice Collard, Steve Groom, Vladimir Kudryavtsev, John Wilkin, Victor Navarro, Alex Babanin, Matthew Martin, John Siddorn, Andrew Saulter, Tom Rippeth, Bill Emery, Nikolai Maximenko, Roland Romeiser, Hans Graber, Aida Alvera Azcarate, Chris W. Hughes, Doug Vandemark, Jose Da Silva, Peter Jan Van Leeuwen, Alberto Naveira-Garabato, Johannes Gemmrich, Amala Mahadevan, Jose Marquez, Yvonne Munro, Sam Doody, Geoff Burbidge Aug 2019

Seastar: A Mission To Study Ocean Submesoscale Dynamics And Small-Scale Atmosphere-Ocean Processes In Coastal, Shelf And Polar Seas, Christine Gommenginger, Bertrand Chapron, Andy Hogg, Christian Buckingham, Baylor Fox-Kemper, Leif Eriksson, Francois Soulat, Clement Ubelmann, Francisco Ocampo-Torres, Bruno Buongiorno Nardelli, David Griffin, Paco Lopez-Dekker, Per Knudsen, Ole Andersen, Lars Stenseng, Neil Stapleton, William Perrie, Nelson Violante-Carvalho, Johannes Schulz-Stellenfleth, David Woolf, Jordi Isern-Fontanet, Fabrice Ardhuin, Patrice Klein, Alexis Mouche, Ananda Pascual, Xavier Capet, Daniele Hauser, Ad Stoffelen, Rosemary Morrow, Lotfi Aouf, Øyvind Breivik, Lee-Leung Fu, Johnny A. Johannessen, Yevgeny Aksenov, Lucy Bricheno, Joel Hirschi, Adrien C. H. Martin, Adrian P. Martin, George Nurser, Jeff Polton, Judith Wolf, Harald Johnsen, Alexander Soloviev, Gregg A. Jacobs, Fabrice Collard, Steve Groom, Vladimir Kudryavtsev, John Wilkin, Victor Navarro, Alex Babanin, Matthew Martin, John Siddorn, Andrew Saulter, Tom Rippeth, Bill Emery, Nikolai Maximenko, Roland Romeiser, Hans Graber, Aida Alvera Azcarate, Chris W. Hughes, Doug Vandemark, Jose Da Silva, Peter Jan Van Leeuwen, Alberto Naveira-Garabato, Johannes Gemmrich, Amala Mahadevan, Jose Marquez, Yvonne Munro, Sam Doody, Geoff Burbidge

Marine & Environmental Sciences Faculty Articles

High-resolution satellite images of ocean color and sea surface temperature reveal an abundance of ocean fronts, vortices and filaments at scales below 10 km but measurements of ocean surface dynamics at these scales are rare. There is increasing recognition of the role played by small scale ocean processes in ocean-atmosphere coupling, upper-ocean mixing and ocean vertical transports, with advanced numerical models and in situ observations highlighting fundamental changes in dynamics when scales reach 1 km. Numerous scientific publications highlight the global impact of small oceanic scales on marine ecosystems, operational forecasts and long-term climate projections through strong ageostrophic circulations, large …

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An Analysis Of Differential Reflectivity Arc Characteristics In 109 Supercell Storms, Matthew Wilson Jun 2019

An Analysis Of Differential Reflectivity Arc Characteristics In 109 Supercell Storms, Matthew Wilson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Differential reflectivity (ZDR)arcs are one of the most prominent dual-polarization features of supercell storms, and are manifest as an arc-shaped area of high ZDR along a supercell’s forward flank reflectivity gradient. Since previous modelling studies have hypothesized that the magnitude of the drop-size sorting by the storm-relative wind which creates the arc signature is related to the strength of the low-level shear and SRH in a storm’s environment, the presence of a strong ZDR arc is often said to indicate that a storm may have the potential to develop strong low-level rotation and potentially become tornadic. …

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Numerical Investigations Of Atmospheric Rivers And The Rain Shadow Over The Santa Clara Valley, Dalton Behringer, Sen Chiao Mar 2019

Numerical Investigations Of Atmospheric Rivers And The Rain Shadow Over The Santa Clara Valley, Dalton Behringer, Sen Chiao

Faculty Publications, Meteorology and Climate Science

This study investigated precipitation distribution patterns in association with atmospheric rivers (ARs). The Weather Research and Forecasting (WRF) model was employed to simulate two strong atmospheric river events. The precipitation forecasts were highly sensitive to cloud microphysics parameterization schemes. Thus, radar observed and simulated ZH and ZDR were evaluated to provide information about the drop-size distribution (DSD). Four microphysics schemes (WSM-5, WSM-6, Thompson, and WDM-6) with nested simulations (3 km, 1 km, and 1/3 km) were conducted. One of the events mostly contained bright-band (BB) rainfall and lasted less than 24 h, while the other contained both BB and non-bright-band …

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Radar Studies Of Height-Dependent Equatorial F Region Vertical And Zonal Plasma Drifts, S. A. Shidler, F. S. Rodrigues, B. G. Fejer, M. A. Milla Feb 2019

Radar Studies Of Height-Dependent Equatorial F Region Vertical And Zonal Plasma Drifts, S. A. Shidler, F. S. Rodrigues, B. G. Fejer, M. A. Milla

All Physics Faculty Publications

We present the results of an analysis of long-term measurements of ionospheric F region E × B plasma drifts in the American/Peruvian sector. The analysis used observations made between 1986 and 2017 by the incoherent scatter radar of the Jicamarca Radio Observatory. Unlike previous studies, we analyzed both vertical and zonal components of the plasma drifts to derive the geomagnetically quiet time climatological variation of the drifts as a function of height and local time. We determine the average behavior of the height profiles of the drifts for different seasons and distinct solar flux conditions. Our results show good agreement …

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Radar Quantification, Temporal Analysis And Influence Of Atmospheric Conditions On A Roost Of American Robins (Turdus Migratorius) In Oklahoma, Matthew S. Van Den Broeke Jan 2019

Radar Quantification, Temporal Analysis And Influence Of Atmospheric Conditions On A Roost Of American Robins (Turdus Migratorius) In Oklahoma, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Radar observations present a way to monitor large, mobile populations across long temporal scales, and are especially valuable when individual scatterers are challenging to count visually. The focus of this study is a large and relatively homogeneous wintertime roost of American Robins (Turdus migratorius) in central Oklahoma. Radar observations are used to estimate the roost population through winter 2010–2011, and the population time series is related to weather variables and radar beam propagation. Radar-estimated roost population gradually increased to an estimated peak of 1.5–2 million individuals from November 2010 to January 2011, and then decreased in a more …

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Multi-Instrumented Observations Of The Equatorial F-Region During June Solstice: Large-Scale Wave Structures And Spread-F, Fabiano S. Rodrigues, Dustin A. Hickey, Weijia Zhan, Carlos R. Martinis, B. G. Fejer, Marco A. Milla, Juan F. Arratia Mar 2018

Multi-Instrumented Observations Of The Equatorial F-Region During June Solstice: Large-Scale Wave Structures And Spread-F, Fabiano S. Rodrigues, Dustin A. Hickey, Weijia Zhan, Carlos R. Martinis, B. G. Fejer, Marco A. Milla, Juan F. Arratia

All Physics Faculty Publications

Typical equatorial spread-F events are often said to occur during post-sunset, equinox conditions in most longitude sectors. Recent studies, however, have found an unexpected high occurrence of ionospheric F-region irregularities during June solstice, when conditions are believed to be unfavorable for the development of plasma instabilities responsible for equatorial spread-F (ESF). This study reports new results of a multi-instrumented investigation with the objective to better specify the occurrence of these atypical June solstice ESF in the American sector and better understand the conditions prior to their development. We present the first observations of June solstice ESF events …

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The National Wildlife Strike Database: A Scientific Foundation To Enhance Aviation Safety, Richard A. Dolbeer, Michael J. Begier, John R. Weller Jan 2018

The National Wildlife Strike Database: A Scientific Foundation To Enhance Aviation Safety, Richard A. Dolbeer, Michael J. Begier, John R. Weller

USDA Wildlife Services: Staff Publications

The U.S. Federal Aviation Administration's (FAA) National Wildlife Strike Database (NWSD) documents reports of civil aircraft collisions with wildlife in USA. The NWSD has been managed by the Wildlife Services Program of the U.S. Department of Agriculture through an interagency agreement since its inception. Although the NWSD includes about 170,000 reports of civil aircraft collisions with wildlife (97% birds) from 1990-2015 (14,000 in 2015), the overriding focus has been the quality control of data entered for over 90 variables ranging from species and numbers of wildlife struck, location and time of day, phase and height of flight, aircraft type, components …

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Aeromagnetic, Gravity, And Differential Interferometric Synthetic Aperture Radar Analyses Reveal The Causative Fault Of The 3 April 2017 MW 6.5 Moiyabana, Botswana, Earthquake, Folarin Kolawole, Estella A. Atekwana, S. Malloy, Dorothy Sarah Stamps, Raphael Grandin, Mohamed G. Abdel Salam, Khumo Leseane, Elisha M. Shemang Sep 2017

Aeromagnetic, Gravity, And Differential Interferometric Synthetic Aperture Radar Analyses Reveal The Causative Fault Of The 3 April 2017 MW 6.5 Moiyabana, Botswana, Earthquake, Folarin Kolawole, Estella A. Atekwana, S. Malloy, Dorothy Sarah Stamps, Raphael Grandin, Mohamed G. Abdel Salam, Khumo Leseane, Elisha M. Shemang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

On 3 April 2017, a Mw 6.5 earthquake struck Moiyabana, Botswana, nucleating at >20 km focal depth within the Paleoproterozoic Limpopo-Shashe orogenic belt separating the Archean Zimbabwe and Kaapvaal Cratons. We investigate the lithospheric structures associated with this earthquake using high-resolution aeromagnetic and gravity data integrated with Differential Interferometric Synthetic Aperture Radar (DInSAR) analysis. Here we present the first results that provide insights into the tectonic framework of the earthquake. The ruptured fault trace delineated by DInSAR aligns with a distinct NW striking and NE dipping magnetic lineament within the Precambrian basement. The fault plane solution and numerical modeling …

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Impact Of Spatial Averaging On Radar Reflectivity At Internal Snowpack Layer Boundaries, N. Rutter, H.P. Marshall, K. Tape, R. Essery, J. King Dec 2016

Impact Of Spatial Averaging On Radar Reflectivity At Internal Snowpack Layer Boundaries, N. Rutter, H.P. Marshall, K. Tape, R. Essery, J. King

CGISS Publications and Presentations

Microwave radar amplitude within a snowpack can be strongly influenced by spatial variability of internal layer boundaries. We quantify the impact of spatial averaging of snow stratigraphy and physical snowpack properties on surface scattering from near-nadir frequency-modulated continuous- wave radar at 12–18 GHz. Relative permittivity, density, grain size and stratigraphic boundaries were measured in-situ at high resolution along the length of a 9 m snow trench. An optimal range of horizontal averaging (4–6 m) was identified to attribute variations in surface scattering at layer boundaries to dielectric contrasts estimated from centimetre-scale measurements of snowpack stratigraphy and bulk layer properties. Single …

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Analyzing Accuracy Of The Lufft Ws600 In Remotely Measuring Precipitation Events, Justin Gay Aug 2016

Analyzing Accuracy Of The Lufft Ws600 In Remotely Measuring Precipitation Events, Justin Gay

STAR Program Research Presentations

The goal of this project was to analyze the accuracy of the Lufft WS600 Weather Sensor in measuring the rate of both liquid and solid precipitation. Measurement accuracy, especially in remote locations, can be difficult to obtain and quantify. Wind, blowing debris, and atmospheric particles can all have the capacity to interfere with instruments that are not being continuously compared to manual observations. Access to quality precipitation data sets are important for both hydrologic and weather forecasting, climate monitoring, and understanding the role of water cycling through ecosystems. Commercially, weather sensors are heavily relied upon by the Federal Aviation Administration …

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Comparison Of Interpolation Technique For Rain Gauge Data Through The Distributed Rainfall-Runoff Model, Byung-Jin So, Ji-Young Yoo, Hyun-Han Kwon Aug 2014

Comparison Of Interpolation Technique For Rain Gauge Data Through The Distributed Rainfall-Runoff Model, Byung-Jin So, Ji-Young Yoo, Hyun-Han Kwon

International Conference on Hydroinformatics

Precipitation estimated from different measuring techniques such as rain gauge, radar and satellite have some similarities, but there are also differences among them. For example, techniques based on radar and satellite data underestimate rainfall than those using rain gauge data. In addition, many different interpolation techniques have been used to measure spatial pattern of precipitation but it is still difficult to have an accurate pattern by any one of them. The differences between the rainfall estimates from different techniques vary seasonally as well as regionally so that the radar or satellites are not directly applied into hydrologic analysis. In this …

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Pcswmm Real Time Flood Forecasting – Toronto, Canada, Mark Randall, Rob James, William James, Karen Finney, Michael Heralall Aug 2014

Pcswmm Real Time Flood Forecasting – Toronto, Canada, Mark Randall, Rob James, William James, Karen Finney, Michael Heralall

International Conference on Hydroinformatics

Flooding in urban areas can cause significant property damage and human injury. Recent extreme precipitation events in the Toronto area have highlighted the need for enhanced warning systems to inform decision making prior to a storm’s arrival. To improve the accuracy and lead time of flood forecasting, Computational Hydraulics International and the Toronto and Region Conservation Authority have developed a high resolution, deterministic, physically-based remote-sensing real-time flood forecasting and web-based decision support system, and applied it to the Don River and Etobicoke Creek watersheds. Using PCSWMM Real-Time, NEXRAD radar data, US EPA SWMM5, HTML5 and Google Maps the system forecasts …

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Floodalert: A Simplified Radar-Based Ews For Urban Flood Warning, Xavier Llort, Rafael Sánchez-Diezma, Alvaro Rodríguez, David Sancho, Marc Berenguer, Daniel Sempere-Torres Aug 2014

Floodalert: A Simplified Radar-Based Ews For Urban Flood Warning, Xavier Llort, Rafael Sánchez-Diezma, Alvaro Rodríguez, David Sancho, Marc Berenguer, Daniel Sempere-Torres

International Conference on Hydroinformatics

Urban floods can be caused by intense rainfall accumulations in short time periods that eventually exceed the capacity of the sewer networks. Despite the efforts made in the last years in all cities to increase the sewer’s capacity many cities are still exposed to these heavy rainfall events. In this work, we present a simplified flood Early Warning System, called FloodAlert, based on the use of radar observations to issue local flood warnings. Although precipitation accumulation estimates based on radar observations may suffer from different sources of error, they may also be the quickest way to obtain a reliable estimate …

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Wibasin: Basin Management Through An Integrated Platform, Xavier Llort, Rafael Sánchez-Diezma, David Sancho, Alvaro Rodríguez, Marc Berenguer, Daniel Sempere-Torres Aug 2014

Wibasin: Basin Management Through An Integrated Platform, Xavier Llort, Rafael Sánchez-Diezma, David Sancho, Alvaro Rodríguez, Marc Berenguer, Daniel Sempere-Torres

International Conference on Hydroinformatics

A key issue in basin and dam management is the correct estimation of accumulated rainfall (observed as well as forecasted) over the catchment (over the characteristic concentration time for critical short-term management, and over longer time periods to anticipate rainfall situations). In this work we present a platform for basin and dam management, called WiBasin, which integrates different sources of precipitation (both observed and forecasted) in a continuous time series of hourly rainfall accumulation fields, having the best precipitation estimation available at each time step. Optimal rainfall estimates used for the past time steps are based on a geostatistical approach …

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Hidromet: A Cloud-Based Ews Platform For Real Time Urban Flood Warning, Alvaro Rodríguez, Xavier Llort, David Sancho, Rafael Sánchez-Diezma, Ramon Bella, Vicente Gomez Aug 2014

Hidromet: A Cloud-Based Ews Platform For Real Time Urban Flood Warning, Alvaro Rodríguez, Xavier Llort, David Sancho, Rafael Sánchez-Diezma, Ramon Bella, Vicente Gomez

International Conference on Hydroinformatics

Urban real time flood’s Early Warning Systems have been traditionally based on the use of punctual precipitation observations (raingauges) to model the sewer network’s behaviour by means of hydraulic models. Since a key issue in the EWS is the leadtime in detecting potential risks, Hidromet takes advantage of radar nowcasting techniques to feed a hydraulic model, not only with observed precipitation by raingauges, but also with forecasted precipitation for the following few hours. Radar nowcasting techniques allow forecasting the precipitation with a high degree of accuracy. This fact, together with the rapid update of the forecasts (typically around 10 minutes), …

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On The Added Value Of Radar Data In Hydrological Modelling And Flood Forecasting, Niels Van Steenbergen, Patrick Willems Aug 2014

On The Added Value Of Radar Data In Hydrological Modelling And Flood Forecasting, Niels Van Steenbergen, Patrick Willems

International Conference on Hydroinformatics

Good quality rainfall data are essential in hydrological modelling and flood forecasting. Classically, rain gauge data are being used as rainfall input for hydrological modelling, but they only provide point information. Because rainfall can be highly variable in space, radar images can provide important additional spatial information, but the quantitative rainfall data quality of these images is often limited. Merging techniques between rain gauge and radar data can provide a solution to this problem. In this research, a simple kriging merging technique, making use of two C-band radars, is tested for the Demer catchment in Belgium. Three periods with different …

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