A5085830055- Soil Moisture and Remote Sensing
- Cryospheric studies and observations
- Climate change and permafrost
- Precipitation Measurement and Analysis
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Plant Water Relations and Carbon Dynamics
- Remote Sensing in Agriculture
- Advanced Nanomaterials in Catalysis
- Landslides and related hazards
- Gas Sensing Nanomaterials and Sensors
- Hydrology and Drought Analysis
- Advanced Chemical Sensor Technologies
- Microwave and Dielectric Measurement Techniques
- Geological formations and processes
- Climate variability and models
- Advanced SAR Imaging Techniques
- Remote Sensing and LiDAR Applications
- Remote Sensing and Land Use
- Species Distribution and Climate Change
- Geophysical Methods and Applications
- Soil and Unsaturated Flow
- Geology and Paleoclimatology Research
- Advanced Photocatalysis Techniques
- Rangeland Management and Livestock Ecology
- Land Use and Ecosystem Services
Nanjing University of Information Science and Technology
2017-2023
University of Twente
2021
University of Electronic Science and Technology of China
2013-2015
A good knowledge of the quality satellite soil moisture products is great importance for their application and improvement. This paper examines performance eight satellite-based products, including Soil Moisture Active Passive (SMAP) passive Level 3 (L3), Ocean Salinity (SMOS) Centre Aval de Traitement des Données SMOS (CATDS) L3, Japan Aerospace Exploration Agency (JAXA) Advanced Microwave Scanning Radiometer 2 (AMSR2) Land Parameter Retrieval Model (LPRM) AMSR2 European Space (ESA) Climate...
In this study, the Standardized Precipitation Evaporation Index (SPEI) was applied to characterize drought conditions in Southwest China from 1982–2012. The SPEI calculated by precipitation and temperature data for various accumulation periods. Based on SPEI, multi-scale patterns, trend, spatio-temporal extent of were evaluated, respectively. results explicitly showed a drying trend China. mean values at five time scales all decreased significantly. Some moderate severe droughts captured...
The spatiotemporal distribution of soil moisture over the Tibetan Plateau is important for understanding regional water cycle and climate change. In this paper, surface in northeastern estimated from time-series VV-polarized Sentinel-1A observations by coupling cloud model (WCM) advanced integral equation (AIEM). vegetation indicator WCM represented leaf area index (LAI), which smoothed interpolated Terra Moderate Resolution Imaging Spectroradiometer (MODIS) LAI eight-day products. AIEM...
This paper presents a microwave/optical synergistic methodology to retrieve soil moisture in an alpine prairie. The adequately represents the scattering behavior of vegetation-covered area by defining vegetation and below. Integral Equation Method (IEM) was employed determine backscattering underlying soil. modified Water Cloud Model (WCM) used reduce effect vegetation. Vegetation coverage, which can be easily derived from optical data, incorporated this method account for gap information....
The newest soil moisture-dedicated satellite, the Soil Moisture Active Passive (SMAP) mission, provides global maps of moisture using concurrent L-band radar and radiometer acquisitions. To support ongoing validation activities SMAP products, in this paper, we examined retrieval accuracy four products by well-calibrated dense situ measurements from Little Washita Watershed network, one core sites with intensive ground sampling. include active (3 km), passive (36 active-passive (9 enhanced...
The distribution of soil moisture is important for modeling hydrological and climatological processes to understand the Earth energy cycle balance. major difficulty retrieval in vegetated areas how separate individual scattering contribution moisture, vegetation, surface roughness from backscattered radar signal. In this paper, a semi-empirical method was proposed retrieve Ruoergai prairie using single temporal Radarsat-2 data. It formulated by integrating advanced integral equation model...
Soil moisture is a pivotal hydrological variable that links the terrestrial water, energy, and carbon cycles. In this article, new soil (SM) index (SMI), which aims to capture temporal variability of SM, irrespective cloud cover solar illumination, was developed by using L-band SM active passive (SMAP) radiometer observations. The SMI proposed on basis two key foundations: 1) vegetation roughness have similar effects "depolarization" microwave emission, while enhances polarization...
Soil moisture retrieval is often confounded by the influence of vegetation and surface roughness on backscattered radar signal in vegetated areas. In this study, a semi-empirical methodology proposed to retrieve soil prairie The effect eliminated ratio method water cloud model (WCM), respectively. conditions are characterized leaf area index (LAI), content (VWC), normalized difference (NDVI), enhanced (EVI), To remove dependence roughness, dielectric constant explicitly expressed as function...
Soil moisture is an essential variable in the land surface ecosystem, which plays important role agricultural drought monitoring, crop status and yield prediction. High-resolution radar data can be combined with optical remote-sensing to provide a new approach estimate high-resolution soil over vegetated areas. In this paper, Sentinel-1A Moderate Resolution Imaging Spectroradiometer (MODIS) are retrieve fields. The advanced integral equation model (AIEM) utilized calculate scattering...
Active and passive microwave signatures respond differently to the land surface provide complementary information on characteristics of observed scenes. The objective this paper is explore synergy active radar radiometer observations at same spatial scale constrain a discrete radiative transfer model, Tor Vergata (TVG) gain insights into scattering emission mechanisms over grasslands. TVG model can simultaneously simulate backscattering coefficient emissivity with set input parameters. To...
Nonvolume decorrelation (γ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Nonvol</sub> ) united with the unknown ground contribution will bring a 2-D ambiguity to volume-only coherence, making inversion underdetermined even when multiple baselines are available. In context of random volume over (RVoG) model and three-stage algorithm, this paper theoretically presented varied response different both γ contribution, then proposed new...
In arid prairie, soil moisture has a substantial impact on the prairie resource management. The synthetic aperture radar (SAR) based retrieval is often hampered by vegetation effects backscattering coefficient. A new method been proposed to retrieve using TerraSAR-X data. developed included bare σppsoilo simulation, effect correction, and relationship between establishment. surface was described forward advanced integral equation model. influence eliminated through an empirical ratio method....
Soil moisture is an important state variable of the land surface ecosystem. In this paper, water cloud model (<small>WCM</small>) and advanced integral equation (<small>AIEM</small>) are coupled to retrieve soil using time series Sentinel-1A data moderate resolution imaging spectroradiometer (<small>MODIS</small>) data. Normalized difference vegetation index (<small>NDVI</small>), enhanced (<small>EVI</small>), leaf area...
Active and passive microwave characteristics of diurnal soil freeze-thaw transitions their relationships are crucial for developing retrieval algorithms the liquid water content ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta _{\mathrm {liq}}$ </tex-math></inline-formula> ) freeze/thaw state, which, however, have been less explored. This study investigates these via analysis ground-based...
Potential of constraining semi-empirical model with physically-based simulations has long been recognized. This study contributes to this topic through the assessment backscatter coefficient (o) and soil moisture retrieval using water cloud (WCM) constrained by a discrete scattering model. The WCM is coupled Oh Dubois models, respectively. One year C-band co-polarized o are collected ground-based scatterometer deployed in seasonally frozen Tibetan meadow ecosystem. It found that: i)...
Vegetation optical depth (VOD), as a microwave-based estimate of vegetation water and biomass content, is increasingly used to study the impact global climate environmental changes on vegetation. However, current operational VOD products have coarse spatial resolution (~25 km), which limits their use for agriculture management dynamics monitoring at regional scales (1–5 km). This aims retrieve high-resolution from C-band Sentinel-1 backscatter data over grassland Heihe River Basin in...