A5054675899- Geophysics and Gravity Measurements
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- GNSS positioning and interference
- Climate variability and models
- Flood Risk Assessment and Management
- earthquake and tectonic studies
- Hydrology and Watershed Management Studies
- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Soil Moisture and Remote Sensing
- Inertial Sensor and Navigation
- Meteorological Phenomena and Simulations
- Ionosphere and magnetosphere dynamics
- Tropical and Extratropical Cyclones Research
- Geology and Paleoclimatology Research
- Planetary Science and Exploration
- Earthquake Detection and Analysis
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Space Exploration and Technology
- Precipitation Measurement and Analysis
- Methane Hydrates and Related Phenomena
- Underwater Acoustics Research
- Electromagnetic Scattering and Analysis
- Electromagnetic Simulation and Numerical Methods
The Ohio State University
2014-2023
University School
2009
Center For Remote Sensing (United States)
2003-2004
The accuracy of state-of-the-art global barotropic tide models is assessed using bottom pressure data, coastal gauges, satellite altimetry, various geodetic data on Antarctic ice shelves, and independent tracked orbit perturbations.Tide under review include empirical, purely hydrodynamic ("forward"), assimilative dynamical, i.e., constrained by observations.Ten dominant tidal constituents in the diurnal, semidiurnal, quarter-diurnal bands are considered.Since last major model comparison...
An algorithm for detecting coherence in Cyclone Global Navigation Satellite System (CYGNSS) mission delay-Doppler maps (DDMs) is presented. Because CYGNSS DDMs report only the observed power without phase information, uses estimates of "spread" within DDM to flag coherency. Since estimate used a ratio powers differing portions DDM, it less sensitive absolute calibration and GPS C/A code type observed, applied Level-1 uncalibrated DDMs. The basic detector formulation described along with...
Abstract The Ganges–Brahmaputra–Meghna (GBM) river basins exhibit extremes in surface water availability at seasonal to annual time scales. However, because of a lack basinwide hydrological data from situ platforms, whether they are real or historical, management has been quite challenging for the 630 million inhabitants. Under such circumstances, large-scale and spatially distributed model, forced with more widely available satellite meteorological data, can be useful generating high...
Tsunamis often travel long distances without losing power and severely devastate some coastal areas while leaving others with little damage. This unpredictable situation has been a major challenge for accurate timely tsunami forecasting to facilitate early‐warning possible evacuations of affected communities disturbing the lives others. Here we show evidence from satellite altimetry observations 2011 Tohoku‐Oki earthquake‐induced that sheds light on this issue. Three satellites observed same...
The Qinghai-Tibetan plateau (QTP), also known as the Third Pole and World Water Tower, is largest highest with distinct competing surface subsurface processes. It covered by a large layer of discontinuous sporadic alpine permafrost which has degraded 10% during past few decades. average active thickness (ALT) increase rate approximately 7.5 cm·yr−1 from 1995 to 2007, based on soil temperature measurements 10 borehole sites along Highway, 6.3 cm·yr−1, 2006–2010, using profiles for 27...
Abstract. The capabilities of radar altimetry to measure inland water bodies are well established, and several river datasets available. Here we produced a globally distributed dataset, the Global River Radar Altimeter Time Series (GRRATS), using Envisat Ocean Surface Topography Mission (OSTM)/Jason-2 altimeter data spanning time period 2002–2016. We developed method that runs unsupervised, without requiring parameterization at measurement location, dubbed virtual station (VS) level, applied...
Previous studies using satellite radar altimetry to observe inland river and wetland water level changes usually spatially average high-rate (10-Hz for TOPEX, 18-Hz Envisat) measurements. Here we develop a technique apply retracking of TOPEX waveforms by optimizing the estimated retracked gate positions Offset Center Gravity retracker. This study, first time, utilizes stacking data over Louisiana concludes that observed each 10-Hz with along-track sampling ∼660 m exhibit variations,...
We validated Jason-2 satellite altimeter Sensor Geophysical Data Records (SGDR) by retracking 20-Hz radar waveforms over the California coastal ocean using cycles 7–34, corresponding to September 2008–June 2009. The performance of ocean, ice, threshold, and modified threshold retrackers are examined a reference geoid based on Earth Gravitational Model 2008 (EGM08). Over shallow (depth < 200 m), retracker, which is developed for noisy with preleading edge bump, outperforms other retrackers....
A robust method to estimate vertical crustal motions by combining geocentric sea level measurements from decadal (1992 -2003) TOPEX/POSEIDON satellite altimetry and long-term (> 40 years) relative records tide gauges using a novel Gauss-Markov stochastic adjustment model is presented.These results represent an improvement over prior study (Kuo et al. 2004) in Fennoscandia, where the observed are primarily attributed incomplete Glacial Isostatic Adjustment (GIA) region since Last Maximum...
This article describes absolute calibration results for both JASON-1 and TOPEX Side B (TSB) altimeters obtained at the Lake Erie site, Marblehead, Ohio, USA. Using 15 overflights, estimated JASON altimeter bias Marblehead is 58 ± 38 mm, with an uncertainty of 19 mm based on detailed error analysis. Assuming that TSB negligible, relative estimates using data from TSB-JASON formation flight period 48 water level gauges around entire Great Lakes confirmed results. Global analyses dual-satellite...
Cycles 4 to 54 of TOPEX data have been analyzed through comparisons with the mean sea surface given on distributed geophysical record (GDR). Two inverted barometer correction procedures were considered for reduction. One used a constant atmospheric pressure all while one adopted use, most computations, introduced cycle average pressure. The maximum difference between two estimates was 3.0 cm clear annual signal. With modified compared Ohio State University (OSU) surface, GDR, estimate three...
The 26 December 2004 Indian Ocean tsunami was the first earthquake of its magnitude to occur since advent both digital seismometry and satellite radar altimetry. Both have independently recorded event from different physical aspects. seismic data has then been used estimate fault parameters, a three‐dimensional ocean‐general‐circulation‐model (OGCM) coupled with information simulate satellite‐observed waves. Here we show that these two datasets consistently provide source using independent...
Measuring sea surface height (SSH) using satellite altimetry in coastal ( from coasts) and shallow water region has long been a challenge since the radar altimeter waveforms are often contaminated by complex topography do not conform to theoretical Brown waveform shapes. The land contamination or variation due ocean dynamics induce spurious peaks that deviate Brown's model as footprint approaches leaves shoreline. These should be mitigated minimize error determination of leading edge...
Abstract This study presents results of Jason-1 (J1) and Jason-2 (J2) radar altimetry absolute calibration (cal/val) over the Marblehead lake water level gauge, with an aid a GPS buoy, in Lake Erie, Great Lakes, North America. The altimeter bias is estimated using height difference between surface situ data each 10-day repeat cycle. estimates for J1 are 81 ± 2 70 mm Geophysical Data Record (GDR) Versions 'B' 'C', respectively, 148 5 147 7 (IGDR) J2, respectively. slightly smaller compared at...
Abstract Two methods to assess ocean tide models, the current method and total discrepancy method, are compared from perspective of their relationship root-mean-square difference tidal sea surface height (total discrepancy). These two identically same when there is only one spatial location involved. When more than involved, at each location, averaged discrepancy. The result always larger or equal that method. Monte Carlo simulation indicates between results increases with increasing...
The use of satellite radar altimetry has long been extended to areas other than the deep-ocean primarily because advances in waveform retracking methodologies.However, algorithms are limited a handful shapes return echoes over assumed known surfaces, while numerous unknown waveforms exist due complexity real-world land cover and surfaces.Measurements surface with seasonal or ephemeral patterns could thus degrade accuracy varying characteristics from corresponding backscatters.In this study,...
This study demonstrates the use of satellite radar altimetry to detect solid Earth deformation signals such as Glacial Isostatic Adjustment (GIA).Our region covers moderately flat land surfaces seasonally covered by snow/ice/vegetation.The maximum uplift ~10 mm yr -1 is primarily due incomplete glacial isostatic rebound that occurs around Hudson Bay, North America.We decadal (1992 -2002) surface height measurements from TOPEX/POSEIDON generate changes time series for 12 selected locations in...
Abstract It has been more than a decade since the last comprehensive accuracy assessment of global ocean tide models. Here, we conduct an evaluation barotropic corrections, which were computed using FES2004 and GOT00.2, other models on Jason-2 altimetry Geophysical Data Record (GDR), with focus selected coastal regions energetic dynamics. We compared nine historical contemporary pelagic tidal constants multiple satellite mission (T/P, ERS-1/-2, Envisat, GFO, Jason-1/-2) sea level anomalies...
We explored the application of satellite radar altimetry for monitoring small inland bodies water and hydrologic studies using a water-detection algorithm, optimally retracked TOPEX/POSEIDON data at 10-Hz sampling, investigated use backscatter to improve land cover classification. The procedure was demonstrated over Manitoba south-western (SW) Ontario, Amazon River Basin study regions. Compared with an L-band synthetic aperture generated water-land mask, algorithm detected more points basin....
The use of satellite radar altimetry has long been extended to areas other than the deep-ocean primarily because advances in waveform retracking methodologies. However, algorithms are limited a handful shapes return echoes over assumed known surfaces, while numerous unknown waveforms exist due complexity real-world land cover and surfaces. Measurements surface with seasonal or ephemeral patterns could thus degrade accuracy varying characteristics from corresponding backscatters. In this...