A5032878975- Soil Moisture and Remote Sensing
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Precipitation Measurement and Analysis
- Cryospheric studies and observations
- Climate change and permafrost
- Oceanographic and Atmospheric Processes
- Spacecraft and Cryogenic Technologies
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Geophysical Methods and Applications
- Spacecraft Design and Technology
- Soil and Unsaturated Flow
- Ionosphere and magnetosphere dynamics
- Climate variability and models
- Statistical and numerical algorithms
- Tropical and Extratropical Cyclones Research
- Flood Risk Assessment and Management
- Inertial Sensor and Navigation
- earthquake and tectonic studies
- Planetary Science and Exploration
- Earthquake Detection and Analysis
- Seismology and Earthquake Studies
- Soil Geostatistics and Mapping
- Ocean Waves and Remote Sensing
University of Luxembourg
2016-2025
K.N.Toosi University of Technology
2012
Global navigation satellite system (GNSS) multipath reflectometry (MR) has emerged as a new technique that uses signals of opportunity broadcast by GNSS satellites and tracked ground-based receivers to retrieve environmental variables such snow depth. The is based on the simultaneous reception direct or line-of-sight (LOS) transmissions corresponding coherent surface reflections (non-LOS). Until recently, depth retrieval algorithms only used legacy modernized GPS signals. Using multiple...
The Amazon basin, one of the world's largest and most vital ecosystems, presents a formidable challenge for accurately mapping its extensive surface water extent dynamic seasonal long-term variations. This arises from region's dense vegetation persistent cloud coverage, limiting applicability conventional remote sensing technologies. Spaceborne GNSS-R offers promising avenue to complement existing techniques, due distinctive sensitivity water, vegetation, penetration, coupled with high...
This article presents a review on spaceborne Global Navigation Satellite System Reflectometry (GNSS-R), which is an important part of GNSS-R technology and has attracted great attention from academia, industry government agencies in recent years. Compared with ground-based airborne approaches, number advantages, including wide coverage the ability to sense medium- large-scale phenomena such as ocean eddies, hurricanes tsunamis. Since 2014, about seven satellite missions have been...
Dual-frequency GNSS data from onboard Precise Orbit Determination (POD) antennas has emerged as a promising tool for investigating the time-variable components of Earth's gravity field. Over past two decades, POD Low Earth (LEO) satellites have significantly advanced study long-wavelength CubeSats, commonly used class nanosatellites, now support wide range geodetic and non-geodetic applications while maintaining minimal costs, mass, power requirements. In this context, Spire CubeSats...
Spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) has emerged as a pivotal tool with different land applications, prominently encompassing soil moisture estimation. In contrast to conventional radiometer satellites commonly used for this purpose, GNSS-R offers higher spatiotemporal coverage while maintaining cost-effectiveness. The potential of using Positioning System (GPS) reflections measured by the Cyclone (CYGNSS) mission retrieve been previously demonstrated. 2019,...
Observations recorded by the NASA Cyclone Global Navigation Satellite System (CYGNSS) mission have demonstrated significant sensitivity to soil moisture, motivating development of several moisture products. An assessment these products was conducted CYGNSS science team. The results showed that accuracy each product may vary based on environmental factors such as surface roughness, vegetation, or terrain complexity. varied responses led an effort combine into a single blended product, best...
Geodetic Global Navigation Satellite System reflectometry (GNSS-R) uses ground-based signals of opportunity to retrieve sea levels at an intermediate spatial scale. GNSS-R is based on the simultaneous reception Line-of-Sight (LoS) and its coherent GNSS surface reflection (non-LOS) signals. The scope this paper present geodetic applied level altimetry. Signal-to-Noise Ratio (SNR) measurements from a Commercial Off-The-Shelf (COTS) geodetic-quality station Haiti Coast Guard Base in...
Global navigation satellite system reflectometry (GNSS-R) uses signals of opportunity in a bi-static configuration L-band microwave radar to retrieve environmental variables such as water level. The line-of-sight signal and its coherent surface reflection are not separate observables geodetic GNSS-R. temporally constructive destructive oscillations the recorded signal-to-noise ratio (SNR) observations can be used water-surface levels at intermediate spatial scales that proportional height...
Large-scale near-surface soil moisture can be retrieved from Global Navigation Satellite System Reflectometry (GNSS-R) surface reflectivity observations, which are dependent on the signal incidence angle and therefore need to normalized. Using 4 years of Cyclone GNSS (CYGNSS) data, in this study we propose a new method for normalization, accounting spatially varying effects coherent incoherent scattering. The is based linear regression between gridded reflectivity. We applied normalized...
This paper presents high-precision phase altimetric retrievals using the GNSS reflected signals off of sea-ice under grazing angle geometries collected by Spire Global, Inc. satellite constellation. The region and period selected for this study (Hudson Bay James from January to March 2021) were determined be most suitable steady as starting point analysis covered areas. difference between GNSS-R more than 500 coherent reflection profiles a reference surface (composed DTU mean sea TPXO ocean...
Global Navigation Satellite System Reflectometry (GNSS-R) that uses signals of opportunity in L-band microwave frequency is an optimal system for Earth surface remote sensing. Spaceborne GNSS-R a very promising bistatic radar to detect, estimate and monitor inundation extents as it collects GNSS reflections good spatiotemporal resolution not affected by clouds and, some extent, aboveground vegetation. In this contribution, we propose new method the extent Brazilian Pantanal wetland using...
In this work, Spire Global, Inc. carrier phase of GNSS dual-frequency reflected signals under grazing angle (GG-R) are used for sea surface altimetry over the Java Sea, Indonesia. Processing 714 GG-R coherent profiles from January 2020 to October 2021 is carried out retrieve relative height WGS84 applying two methods remove ionospheric delay: an ionosphere-free combination and smoothing frequency-specific correction based on observations. A substantial improvement ∼ 8 cm observed in root...
Sea Surface Height Anomaly (SSHA) measurements are essential for understanding oceanic dynamics, climate variability, and change impacts. While satellite-based altimetry missions the primary source of such measurements, their spatiotemporal resolution may sometimes be insufficient. This study explores potential Global Navigation Satellite Systems Reflectometry (GNSS-R) as an additional approach SSHA retrieval. It exploits L-Band coherent carrier phase collected by radio occultation receivers...