A5089953510- Cryospheric studies and observations
- Millimeter-Wave Propagation and Modeling
- Radio Wave Propagation Studies
- Noise Effects and Management
- Soil Moisture and Remote Sensing
- Acoustic Wave Phenomena Research
- Underwater Acoustics Research
- Hearing Loss and Rehabilitation
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Precipitation Measurement and Analysis
- Geology and Paleoclimatology Research
- Geophysical Methods and Applications
- Climate change and permafrost
- Indoor and Outdoor Localization Technologies
- Power Line Communications and Noise
- Icing and De-icing Technologies
- Ocean Waves and Remote Sensing
- Vibration and Dynamic Analysis
- Wind and Air Flow Studies
- Radioactivity and Radon Measurements
- Probabilistic and Robust Engineering Design
- Atmospheric and Environmental Gas Dynamics
- Speech and Audio Processing
- Arctic and Antarctic ice dynamics
Cold Regions Research and Engineering Laboratory
2016-2025
U.S. Army Engineer Research and Development Center
2017-2024
United States Army
2015-2024
Signature Research (United States)
2023
Atmospheric and Environmental Research
2021
University of Maine
2009-2015
United States Department of the Army
2015
Bucknell University
2012
University of Maine System
2004
Centre National d'Études Spatiales
2001
Abstract. We present the first high-resolution (sub-annual) dust particle data set from West Antarctica, developed Antarctic Ice Sheet (WAIS) Divide deep ice core (79.468° S, 112.086° W), and use it to reconstruct changes in atmospheric circulation over past 2400 years. find a background flux of ~4 mg m−2 year−1 mode size 5–8 μm diameter. Through comparing WAIS record with other records, we observe that coastal lower-elevation sites have higher fluxes coarser distributions (PSDs) than on...
Abstract Interpretation of ice core trace gas records depends on an accurate understanding the processes that smooth atmospheric signal in firn. Much work has been done to understand affecting air transport open pores firn, but a paucity data from trapped bubbles firn‐ice transition region limited ability constrain effect bubble closure processes. Here we present high‐resolution measurements firn density, methane concentrations, nitrogen isotopes, and total content show layering at West...
We describe a microcontroller-based ice core melting and data logging system allowing simultaneous depth coregistration of continuous flow analysis (CFA) (for microparticle conductivity measurement) discrete sample geochemistry microparticles), both supplied from the same melted section. This hybrid employs an parcel tracking algorithm which calculates real-time transport through all portions meltwater handling system, enabling accurate (1 mm) measurements. Signal dispersion is analyzed...
This study examines the links between human perceptions, cognitive biases and neural processing of symmetrical stimuli. While preferences for symmetry have largely been examined in context disorders such as obsessive-compulsive disorder autism spectrum disorders, we examine various these phenomena non-clinical subjects suggest that are distributed throughout typical population part our architecture. In Experiment 1, 82 young adults reported on frequency their behaviors. Subjects also...
Abstract Modern measurement campaigns of man‐made radio frequency (RF) noise have reported results from fixed locations that are assumed to be representative the surroundings. Models derived these measurements include parameters express variability in time and space over very large distances (i.e., differences between cities). Despite rapidly evolving mixture sources, especially modern urban environments, spatial variation RF power at scale streets blocks is essentially unknown high ultra...
A variety of probability density functions (pdfs) have been proposed for scattered signals, which varying analytical advantages and ranges physical applicability. We discuss here modeling with a compound pdf, in basic describing the underlying scattering process, has uncertain parameters or is modulated by variability environment. The modulating pdf are termed hyperparameters. Some previous examples formulations include K-distribution, strong (exponential pdf) gamma mean signal power,...
Abstract A gamma-ray density gauge can provide high-resolution and high-precision measurements of firn ice cores. This study describes the design, energy optimization mass attenuation coefficient calibration Maine Automated Density Gauge Experiment (MADGE), a portable, field-operable used on overland traverses in East Antarctica. The MADGE instrument uses 241 Am source, pulse-mode counting system electronic core diameter calipers to collect (±0.004 g cm −3 ) data from 3–8 are collected at...
The full application and benefits of e-Navigation, as a whole, cannot yet fully be known. Technological developments will continuously change the course national international initiatives in field, lead pace evolution. However, how countries govern support development e-Navigation is very much within realm control. National-level e-navigation governance structures that are capable harnessing innovation supporting needs mariners help ensure only limits to evolution technological. aim this...
Abstract. We present the first high-resolution (sub-annual) dust particle dataset from West Antarctica, developed Antarctic Ice Sheet (WAIS) Divide deep ice core (79.468° S, 112.086° W), and use it to reconstruct past atmospheric circulation. find a background flux of ∼4 mg m−2 yr−1 mode size 5–8 μm diameter. Through comparison with other records, we observe that coastal lower-elevation sites have higher fluxes coarser distributions (PSDs) than on East plateau, suggesting input local sources...
A variety of probability density functions (pdfs) have been proposed for scattered signals, which varying analytical advantages and ranges physical applicability. We discuss here situations modeled by a compound pdf, in basic attributable to the underlying scattering process, has uncertain parameters or is modulated variability environment. The modulating pdf are termed hyperparameters. Some previous examples formulations include K-distribution, strong (exponential pdf) gamma mean signal...
A computational framework is described for modeling acoustic and radio-frequency (RF) signal propagation in complex environments, such as urban, mountainous, forested terrain. In the influences of three-dimensional atmospheric fields terrain variations must be addressed. The approach here involves creation a full environmental data representation (abstraction layer), which can initialized with many different resources, including weather forecasts, digital elevations, landcover types, soil...
Statistical distributions of urban noise levels are influenced by many complex phenomena, including spatial and temporal variations in the source level, multisource mixtures, propagation losses, random fading from multipath reflections. This article provides a broad perspective on varying impacts these phenomena. Distributions incorporating averaging (e.g., gamma noncentral Erlang) tend to be negatively skewed logarithmic (decibel) axes but can positively if process is strongly modulated...
The urban radio-frequency (RF) noise generated by our cities continues to change with time. Although models exist describe the RF as functions of frequency and land use types, very few spatial character on scales city blocks (50–150 m). This work describes a large measurement campaign conducted in Boston, MA. number points collected allowed for calculation correlation field. A simple point source model is then developed, theoretical function derived. Good agreement between experimental data...
The interference of the direct and ground-reflected sound waves is significantly affected by volumetric scattering in atmosphere, such as turbulence forest. In present article, existing theory describing this generalized to three somewhat independent but equally important cases. First, attenuation caused backscattering addressed. Second, extended for statistically quasi-homogeneous which variances length scales temperature wind velocity fluctuations depend on height above ground. Third,...
Abstract The urban radio‐frequency (RF) noise generated by our cities continues to change with time. Although models exist describe the RF as functions of frequency and land use types, very few spatial character or structure on scales city blocks (50–150 m). goal this work is investigate connection between morphology higher‐order statistics field. To achieve goal, a large measurement campaign was conducted in Boston, Massachusetts. Many measurements allowed for calculation correlation power...
We report the results of several field experiments to characterize broadband UHF radiofrequency propagation through mountainous terrain and into deep shadow zones. Utilizing an existing digital broadcast television station (center frequency 497 MHz with a standard 6 bandwidth) as our signal source, we performed spectrum analyzer surveys determine both spatial spectral characteristics signals present within Directional revealed that RF power zones arrives primarily via adjacent topographic...
The White Mountains in New Hampshire provide a location where UHF non-line of sight (NLOS) paths become important. Because line (LOS) are often blocked, reflections from adjacent tree covered slopes, visible to both transmitter and receiver, bistatic propagation path with sufficient intensity. question the reflection mechanism will be discussed using broad band measurements forest models.