Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation,
2024
Air Force Institute of Technology
Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation, Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael L. Dexter, Andrew Kondrath, Stephen Hinton, Ricardo Davila
Faculty Publications
This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal function is distorted by a displacement map, which is generated using horizontal wind data from a Global Forecast System (GFS) weather file. The vertical windspeed and relative humidity are used to mask the creation of clouds to match realistic large-scale weather patterns over the Earth. Small-scale detail is provided by the fractal functions which are tuned to …
Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector,
2024
Department of Physics, University of Dar es Salaam, P.O Box 35063, Dar es Salaam, Tanzania
Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda
Tanzania Journal of Science
Measurement of angular distribution (AD) of the bremsstrahlung spectral temperature from a full dimension of the Electron Cyclotron Resonance Ion Source (ECRIS) along the beam axis is challenging. To overcome some challenges, this paper presents the AD of the bremsstrahlung spectral temperature measured in a full dimension of the ECRIS along the beam axis using data obtained from the Busan Center of Korea Basic Science Institute (KBSI). The bremsstrahlung spectral temperature from 28-GHz ECR Ion source at the KBSI was measured in six, three, and nine azimuthal angles at the injection, centre, and extraction sides of the ECRIS using three …
Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank,
2024
Air Force Institute of Technology
Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank, Benjamin C. Wilson, Santasri R. Bose-Pillai, Jack E. Mccrae, Steven T. Fiorino, Robert P. Freeman, Laura R. Slabaugh
Faculty Publications
The atmosphere’s surface layer (first 50–100 m above the ground) is extremely dynamic and is influenced by surface radiative properties, roughness, and atmospheric stability. Understanding the distribution of turbulence in the surface layer is critical to many applications, such as directed energy and free space optical communications. Several measurement campaigns in the past have relied on weather balloons or sonic detection and ranging (SODAR) to measure turbulence up to the atmospheric boundary layer. However, these campaigns had limited measurements near the surface. We have developed a time-lapse imaging technique to profile atmospheric turbulence from turbulence-induced differential motion or tilts between …
A Climatology Of North American Monsoon Precipitation Over Arizona From Mrms Data,
2024
Embry-Riddle Aeronautical University
A Climatology Of North American Monsoon Precipitation Over Arizona From Mrms Data, Greta Graeler, Mark Sinclair, Curtis N. James
Publications
The North American Monsoon (NAM) is a seasonal shift in pressure and wind which accounts for over half of the southwest’s annual precipitation. North-central Arizona has variable terrain which influences the location and intensity of convective storms. Severe weather such as strong winds, lightning, and hail can cause loss of life, property, and fires. High spatial and temporal resolution data along with reanalysis data is used to identify convective cells and their motion for the 2015 to 2022 NAM seasons. The heaviest precipitation in north-central Arizona is found over the Bradshaw Mountains and is most active in July and August. …
Investigation Of Surface Chemistry From Electron Irradiation Of Synthetic Schreibersite,
2024
Kennesaw State University
Investigation Of Surface Chemistry From Electron Irradiation Of Synthetic Schreibersite, Tyler Davis
Master's Theses
While phosphorus is one of the key elements for life on Earth, it has relatively low abundance in extraterrestrial environments, making it a target for astronomers and astrobiologists interested in the possibility of life beyond our planet. Schreibersite (Fe,Ni)3P is one of the first P-containing minerals to condense during planetary cooling and one of the primary P-containing minerals in iron and stony-iron meteorites. Therefore, it is a likely P-bearing mineral in cometary cores and dust grains within the interstellar medium and circumstellar envelopes. Experiments in this project were performed with the aim of observing the formation of small …
Kinematic And Dynamic Structure Of The 18 May 2020 Squall Line Over South Korea,
2024
Kyungpook National University
Kinematic And Dynamic Structure Of The 18 May 2020 Squall Line Over South Korea, Wishnu Agum Swastiko, Chia-Lun Tsai, Seung Hee Kim, Gyuwon Lee
Institute for ECHO Articles and Research
The diagonal squall line that passed through the Korean Peninsula on the 18 May 2020 was examined using wind data retrieved from multiple Doppler radar synthesis focusing on its kinematic and dynamic aspects. The low-level jet, along with warm and moist air in the lower level, served as the primary source of moisture supply during the initiation and formation process. The presence of a cold pool accompanying the squall line played a role in retaining moisture at the surface. As the squall line approached the Korean Peninsula, the convective bands in the northern segment (NS) and southern segment (SS) of …
Volumetric Reconstruction Of Ionospheric Electric Currents From Tri-Static Incoherent Scatter Radar Measurements,
2024
University of Bergen
Volumetric Reconstruction Of Ionospheric Electric Currents From Tri-Static Incoherent Scatter Radar Measurements, Jone Peter Reistad, Spencer Mark Hatch, Karl M. Laundal, Kjellmar Oksavik, Matthew David Zettergren, Heikki Vanhamaki, Ilkka I. Virtanen
Publications
We present a new technique for the upcoming tri-static incoherent scatter radar system EISCAT 3D (E3D) to perform a volumetric reconstruction of the 3D ionospheric electric current density vector field, focusing on the feasibility of the E3D system. The input to our volumetric reconstruction technique are estimates of the 3D current density perpendicular to the main magnetic field, $\mathbf{j} \perp$, and its co-variance, to be obtained from E3D observations based on two main assumptions: 1) Ions fully magnetised above the $E$ region, set to 200 km here. 2) Electrons fully magnetised above the base of our domain, set to 90 …
The 2022 Hunga Tonga Volcanic Eruption's Impact On Radio Communications,
2024
Utah State University
The 2022 Hunga Tonga Volcanic Eruption's Impact On Radio Communications, Spencer Brothers
Student Research Symposium
On January 15th 2022, the Hunga Tonga volcanic eruption, Figure 1, ejected unprecedented amounts of water into the stratosphere. The resulting plume may present temporary opportunities for long distance radio communication.
Nowcasting Heavy Rainfall With Convolutional Long Short-Term Memory Networks: A Pixelwise Modeling Approach,
2024
Massachusetts Maritime Academy
Nowcasting Heavy Rainfall With Convolutional Long Short-Term Memory Networks: A Pixelwise Modeling Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Soorok Ryu, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos
Institute for ECHO Articles and Research
The recent decades have seen an increasing academic interest in leveraging machine learning approaches to nowcast, or forecast in a highly short-term manner, precipitation at a high resolution, given the limitations of the traditional numerical weather prediction models on this task. To capture the spatiotemporal associations of data on input variables, a deep learning (DL) architecture with the combination of a convolutional neural network and a recurrent neural network can be an ideal design for nowcasting rainfall. In this study, a long short-term memory (LSTM) modeling structure is proposed with convolutional operations on input variables. To resolve the issue of …
Error Analysis Of Numerical Weather Prediction Forecasts And Remotely Sensed Air Properties,
2024
Coastal Carolina University
Error Analysis Of Numerical Weather Prediction Forecasts And Remotely Sensed Air Properties, Caleb R. Sease
Honors Theses
Communication and sensing technologies are influenced by atmospheric properties such as the air’s index of refraction, humidity, and temperature in the marine atmospheric surface layer (MASL). Recent research has demonstrated that radar can remotely sense the index of refraction in the MASL and, sometimes, numerical weather prediction models (NWP) can be used to aid this process. These developments are important because they allow for larger spatial coverage and finer temporal resolution than is possible with in-situ atmospheric sensors. More recently, on-going research is working toward extending this remote sensing capability to humidity using refraction as an intermediary. In order to …
Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform,
2024
Embry-Riddle Aeronautical University
Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford
Doctoral Dissertations and Master's Theses
Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …
Spectroscopy Of Atmospheres,
2024
Old Dominion University
Spectroscopy Of Atmospheres, Randika Dodangodage
Physics Theses & Dissertations
Spectroscopic methods are used to study planetary and stellar atmospheres. The information obtained from spectroscopic studies provides insight into atmospheric compositions and dynamics, which can be used to model and characterize atmospheres and climates. Laboratory-recorded absorption cross-sections are needed to interpret the recorded spectra of planets and stars. High resolution ethane, neopentane, propene, and n-butane spectra have been recorded, and absorption cross-sections have been provided for different temperatures and total pressures with different broadening gases, including hydrogen, helium, and nitrogen. The Atmospheric Chemistry Experiment (ACE) satellite orbits Earth and records spectra through solar occultation limb observations. HOCl is a chlorine …
Interferometric Imaging With Eiscat_3d For Fine-Scale In-Beam Incoherent Scatter Spectra Measurements,
2024
Embry-Riddle Aeronautical University
Interferometric Imaging With Eiscat_3d For Fine-Scale In-Beam Incoherent Scatter Spectra Measurements, M. Zettergren, Devin Huyghebaert, Björn Gustavsson, Juha Vierinen, Andreas Kvammen, John Swoboda, Ilkka Virtanen, Spencer Hatch, Karl M. Laundal
Publications
The 233 MHz EISCAT_3D radar system currently under construction in northern Fennoscandia will be able to resolve ionospheric structures smaller than the transmit beam dimensions through the use of interferometric imaging. This capability is made possible by the modular design and digitization of the 119 91-antenna panels located at the main Skibotn site. The main array consists of a cluster of 109 panels, with 10 outlier panels producing unique interferometry baselines. In the present study synthesized incoherent scatter radar signal measurements are used for interferometric imaging analysis with the EISCAT_3D system. The Geospace Environment Model of Ion-Neutral Interactions (GEMINI) model …
Ground Electric Field, Atmospheric Weather And Electric Grid Variations In Northeast Greece Influenced By The March 2012 Solar Activity And The Moderate To Intense Geomagnetic Storms,
2024
Democritus University of Thrace (DUTH)
Ground Electric Field, Atmospheric Weather And Electric Grid Variations In Northeast Greece Influenced By The March 2012 Solar Activity And The Moderate To Intense Geomagnetic Storms, Georgios Anagnostopoulos, Anastasios Karkanis, Athanasios Kampatagis, Panagiotis Marhavilas, Sofia-Anna Menesidou, Dimitrios Efthymiadis, Stefanos Keskinis, Dimitar Ouzounov, Nick Hatzigeorgiu, Michael Danakis
Mathematics, Physics, and Computer Science Faculty Articles and Research
In a recent paper, we extended a previous study on the solar solar influence to the generation of the March 2012 heatwave in the northeastern USA. In the present study we check the possible relationship of solar activity with the early March 2012 bad weather in northeast Thrace, Greece. To this end, we examined data from various remote sensing instrumentation monitoring the Sun (SDO satellite), Interplanetary space (ACE satellite), the Earth’s magnetosphere (Earth-based measurements, NOAA-19 satellite), the top of the clouds (Terra and Aqua satellites), and the near ground atmosphere. Our comparative data analysis suggests that: (i) the winter-like weather …
Global Empirical Model Of Sporadic-E Occurrence Rates,
2024
Air Force Institute of Technology
Global Empirical Model Of Sporadic-E Occurrence Rates, Eli V. Parsch
Theses and Dissertations
Encompassing the Earth, the ionosphere presents unique challenges to modern communication, navigation, and surveillance technologies. Intense ionization enhancements known as sporadic-E (Es), can degrade and disrupt signals in unpredictable ways. Much work has been done to understand this phenomenon and more recent efforts have attempted to model its behavior and impacts. However, there have been limited efforts at modeling global Es occurrence rates (OR) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E (fbEs) occurrence rates using a Karhunen-Lo´eve Expansion (KLE) of global fbEs OR climatologies built with Global Positioning System radio occultations (GPS-RO) and …
Investigation Of High-Latitude Gnss Radio Occulation Sporadic-E And Auroral-E Measurements,
2024
Air Force Institute of Technology
Investigation Of High-Latitude Gnss Radio Occulation Sporadic-E And Auroral-E Measurements, Kyle D. Roberts
Theses and Dissertations
Abnormal sporadic-E (Es) occurrences were found in the high latitude regions during a recent climatology study by (Hodos, 2022), that calculated sporadic-E occurrence rates derived from a data set of GPS radio occultation (GPS-RO) and ionosondes. In this study, sporadic-E GNSS-RO techniques are shown to falsely attribute sporadic-E events to auroral-E (Ea) events. A comparative study is conducted on GPS-RO measurement techniques to find false occurrence rates for various RO techniques using a single ionosonde site in Gakona, Alaska. Phase-based RO techniques were found to be more likely to falsely attribute sporadic-E as auroral-E, while amplitude …
Modeling Lightning Flashes In Dissimilar Non-Homogeneous Clouds,
2024
Air Force Institute of Technology
Modeling Lightning Flashes In Dissimilar Non-Homogeneous Clouds, Scott R. Wolff
Theses and Dissertations
A new methodology for near-infrared lightning radiative transfer through clouds is presented. High-resolution weather modeling is used to generate realistic three-dimensional non-homogeneous clouds, which are then used as environments for a Monte Carlo simulation of photon multiple scattering from approximations of lightning flashes. Resultant emissions from the cloud tops are in line with previous studies and satellite observations.
Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density,
2024
Air Force Institute of Technology
Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth
Theses and Dissertations
High frequency (HF) communication is a vital aspect of military communication and is highly reliant upon ionospheric conditions. The variation in electron density within the lowest echelon of the ionosphere, the D-region, can significantly impact HF signals, making communication inconsistent and unreliable for these wavelengths. Despite the D-region’s important, research in this area mainly focuses on understanding the impact of space weather anomalies on the upper ionosphere, particularly its higher layers, with relatively little exploration of the D-region. This region, situated closest to the troposphere and stratosphere, has been definitively linked to solar weather events like solar flares and geomagnetic …
Low-Temperature Laboratory Instrumentation For Investigating Ice Crystal Aggregate Formation In The Atmosphere,
2024
University of North Dakota
Low-Temperature Laboratory Instrumentation For Investigating Ice Crystal Aggregate Formation In The Atmosphere, Victor Ojo, Imteaz Osmani, Hallie Boyer Chelmo
Graduate Research Achievement Day Posters
This study addresses the challenge of achieving controlled low temperatures to investigate and provide information on the precise conditions that promote homogenous (≤-38oC) and heterogenous (≥ -38oC) atmospheric ice crystal formation and aggregation, which disrupt aerospace industries and military activity. I present a preliminary design of a novel temperature control setup for generating levitated ice crystal aggregates within a Dual Balance Electrodynamic Trap (DBET). This preliminary design is called the replica low temperature electrodynamic balance (R-LTDBET). The design integrates chilled-coolant-conveying copper tubes encircling the hollow-square-shaped DBET’s external wall to precisely control its inner chamber temperature while incorporating real-time temperature sensing, …
Analyzing The Effects Of Data Variability & Volume On Predicting Particulate Matter (Pm2.5): Insights From A Machine Learning Approach,
2024
CUNY Hunter College
Analyzing The Effects Of Data Variability & Volume On Predicting Particulate Matter (Pm2.5): Insights From A Machine Learning Approach, Jada A. Macharie
Theses and Dissertations
Accurately predicting PM2.5 concentrations are imperative to the future of public health and environmental policies. Machine learning models incorporating spatial and temporal datasets to predict PM2.5 are often limited by data availability constraints and poor resolution satellite imagery.
