A5102954209- Ocean Waves and Remote Sensing
- Flood Risk Assessment and Management
- Railway Engineering and Dynamics
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Underwater Acoustics Research
- Oceanographic and Atmospheric Processes
- Hydrology and Watershed Management Studies
- Coastal and Marine Dynamics
- Geophysics and Gravity Measurements
- Mechanical stress and fatigue analysis
- Geotechnical Engineering and Underground Structures
- Tropical and Extratropical Cyclones Research
- Soil Moisture and Remote Sensing
- Advanced SAR Imaging Techniques
- Meteorological Phenomena and Simulations
- Structural Load-Bearing Analysis
- Remote Sensing and LiDAR Applications
- Air Quality Monitoring and Forecasting
- Hydrology and Sediment Transport Processes
- Automated Road and Building Extraction
- Toxic Organic Pollutants Impact
- Railway Systems and Energy Efficiency
- Air Quality and Health Impacts
- Precipitation Measurement and Analysis
- Infrared Target Detection Methodologies
Jet Propulsion Laboratory
2010-2024
Radar (United States)
2023
University of Illinois Urbana-Champaign
2014-2015
California Institute of Technology
2011-2013
Brigham Young University
2006-2010
University at Buffalo, State University of New York
2010
Houston Advanced Research Center
2002-2005
In this paper, we introduce a reprocessing of the entire SeaWinds on QuikSCAT mission. The goal is to create climate data record suitable for studies and incorporate recent algorithm improvements. Three different levels are produced at Jet Propulsion Laboratory: L1B, geolocated, calibrated, backscatter measurements in chronological order by acquisition time; L2A, binned into geographical grid; L2B, gridded ocean surface wind vectors. This only changes L2A L2B data; have not changed L1B...
Abstract The upcoming Surface Water and Ocean Topography (SWOT) mission will measure water surface heights widths for rivers wider than 100 m. At its native resolution, SWOT height errors are expected to be on the order of meters, which prevent calculation slopes use slope‐dependent discharge equations. To mitigate width errors, high‐resolution measurements grouped into reaches (∼5 15 km), where slope estimated. We describe three automated river segmentation strategies defining optimum...
This paper approaches scatterometer image reconstruction as the inversion of a discrete noisy aperture-filtered sampling operation. Aperture-filtered is presented and contrasted with conventional irregular sampling. Discrete from noise-free samples investigated continuous approaches. The approach enables analytical treatment grid resolution effective imposed by operations. case also explored. A estimator based on maximum posteriori (MAP) estimation proposed to recover measurements. noise...
The Surface Water and Ocean Topography (SWOT) satellite AirSWOT airborne instrument are the first imaging radar-altimeters designed with near-nadir low incidence, 35.75 GHz Ka-band InSAR for mapping terrestrial water storage variability. Remotely sensed surface extents crucial assessing such variability, but confounded by emergent inundated vegetation along shorelines. However, because SWOT-like measurements novel, there remains some uncertainty in ability to detect certain land classes....
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Although the SeaWinds scatterometer was not specifically designed to observe tropical cyclones, new high-resolution wind products resolve much of horizontal structure these storms. However, higher resolution (2.5 km) are inherently noisier than standard 25-km near-surface products. These noise levels combined with rain contamination complicate estimation—particularly in cyclones. Fortunately,...
Although QuikSCAT was originally designed to measure winds at a resolution of 25 km, higher wind and rain products have been developed. The 2.5 km ultra high (UHR) allow data be used for applications involving rain, meso-scale phenomena, in coastal applications. This paper overviews unifies the various UHR discusses their advantages limitations as compared each other conventional product. Theory, consequences assumptions, trade-offs are also discussed.
Increasing axle loads of today’s North American heavy haul freight trains have presented numerous engineering challenges for the design and performance concrete crossties fastening systems. Several research studies been conducted to understand path vertical load from wheel/rail interface through system into crosstie with successful results. However, problems arise due failure components caused by high lateral longitudinal in addition loads. Failed are often seen demanding track environments...
Consistent increases in cumulative freight tonnages, combined with the move towards increased higher-speed intercity passenger rail operation, have placed greater demands on North American railroad infrastructure. Concrete sleepers and fastening system components are known to fail at a wide range of life cycle intervals when subjected demanding loading environments. Such failures can cause track geometry defects, require repetitive maintenance procedures, present critical engineering...
One of the main objectives surface water and ocean topography (SWOT) mission, scheduled for launch in 2021, is to measure inland levels using synthetic aperture radar (SAR) interferometry. A key step toward this objective precisely detect areas. In article, we present a method SWOT images. Water detected based on relative brightness nonwater surfaces. varies throughout swath because system parameters (i.e., antenna pattern), as well phenomenology such wind speed roughness. To handle effects...
This paper approaches wind field estimation from scatterometer measurements as the inversion of a noisy nonlinear sampling operation. The forward model is presented and made discrete for practical purposes. Generally, problem ill-posed at high resolution, which means that there are more parameters to estimate than measurements. A Bayesian approach based on maximum posteriori (MAP) proposed regularize problem. allows simultaneous regular samples high-resolution vector directly...
A Bayesian method for estimating wind and rain in hurricanes from SeaWinds at ultra-high resolution is developed. We use a hurricane model to generate prior distributions the speed, direction, rate. The derived data Tropical Rainfall Measuring Mission Precipitation Radar (TRMM-PR). new reduces variability of standard simultaneous estimates while preserving meso-scale detail.
Although SeaWinds was not originally designed to observe tropical cyclones, new higher resolution products resolve much of the horizontal structure these storms. However, (reported at 2.5 km) are inherently noisier than standard 25 km and high rain rates often associated with hurricanes corrupt wind estimates. Fortunately, storms have which can be exploited using a model. This paper develops procedure for hurricane field estimation from instrument ultra resolution. We develop simplified...
This paper considers sampling and reconstruction theory with application to scatterometer image reconstruction. Backscatter imaging is approached as the inversion of a noisy aperture-filtered operation. A estimator based on maximum posteriori probability (MAP) estimation proposed recover conventional samples from samples. Examples SeaWinds Advanced Wind Scatterometer (ASCAT) are presented.
The SeaWinds scatterometer was developed to mea- sure ocean surface winds from space at a resolution of 25 km. Recently, higher (2.5 km) product has proven useful in several applications. However, high wind field estimates are very noisy and this complicates ambiguity selection. current selection proce- dure is initialized (or nudged) by the low (L2B) result which may not produce sufficiently accurate results. This paper describes an entirely new method for initializing selection, especially...
This paper approaches the noise versus resolution tradeoff in wind scatterometry from a fieldwise retrieval perspective. Theoretical considerations are discussed, and practical implementation is developed applied to SeaWinds scatterometer. The approach compared with conventional approaches, as well numerical weather predictions buoys. new method incorporates knowledge of spectrum reduce impact components signal that expected be noisy while enabling reconstruction fine-scale features...