Results 51 to 60 of about 723 (178)

A Modified Hierarchical Vision Transformer for Soil Moisture Retrieval From CYGNSS Data

Water Resources Research, Volume 62, Issue 1, January 2026.
Abstract This research introduces a new deep learning (DL) framework, multi‐head self‐attention‐aided vision Transformer (MSA‐ViT), for soil moisture (SM) retrieval using Cyclone Global Navigation Satellite System (CYGNSS) data. We first assess the sensitivity of CYGNSS reflectivity (Γ) $({\Gamma })$ to SM, demonstrating a strong physical linkage ...
Qingyun Yan, Yuhan Chen, Yuanjin Pan, Shuanggen Jin, Weimin Huang   +4 more
wiley   +1 more source

A Unified Optimization Framework for LEO Hybrid Constellations Using an Improved Continuous Coefficient Method

Advances in Astronomy, Volume 2026, Issue 1, 2026.
Low Earth orbit (LEO) constellations are increasingly deployed to provide integrated services such as communication, navigation augmentation, and remote sensing. However, traditional constellation designs—such as Walker, streets‐of‐coverage (SoC), and Flower constellations—rely on distinct parameter sets, making unified optimization of hybrid ...
Lin Pan, Lan Du, Zhongkai Zhang, Lundong Zhang, Zejun Liu, Peiyuan Zhou, Chonghui Li, Jianguo Yan   +7 more
wiley   +1 more source

Leveraging the CYGNSS Spaceborne GNSS‐R Observations to Detect Ionospheric Irregularities Over the Oceans: Method and Verification

Space Weather, 2022
The Global Navigation Satellite System (GNSS) has significantly facilitated the detection of ionospheric irregularities. Nevertheless, the ground‐based GNSS stations are inhomogeneously distributed around the world with large gaps, especially in the vast
Xiaodong Ren, Hang Liu, Dengkui Mei, Pengxin Yang, Zhiyu Zhang, Mohamed Freeshah, Xiaohong Zhang   +6 more
doaj   +1 more source

What's Next for Snow: Insights From the NASA Terrestrial Hydrology Program Community Snow Meeting

Earth's Future, Volume 13, Issue 12, December 2025.
Abstract Earth's snow cover strongly influences the climate system and represents an important resource for agricultural, industrial, and domestic water use. The last decade of snow‐focused research has improved our understanding of snow across scales. These efforts have culminated in new snow measurement instruments and methods, operational models for
Kate Hale, Joachim Meyer, Jack Tarricone, Carrie Vuyovich, Megan Mason, Hans‐Peter Marshall, Keith N. Musselman, Noah P. Molotch, Rashmi Shah, Shadi Oveisgharan   +9 more
wiley   +1 more source

GNSS Reflectometry-Based Ocean Altimetry: State of the Art and Future Trends

Remote Sensing
For the past 20 years, Global Navigation Satellite System reflectometry (GNSS-R) technology has successfully shown its potential for remote sensing of the Earth’s surface, including ocean and land surfaces.
Tianhe Xu, Nazi Wang, Yunqiao He, Yunwei Li, Xinyue Meng, Fan Gao, Ernesto Lopez-Baeza   +6 more
doaj   +1 more source

Detecting Localized Floods in Tropical Regions With CYGNSS SmallSat Constellation: A Proof of Concept From the Maritime Continent

Geophysical Research Letters, Volume 52, Issue 20, 28 October 2025.
Abstract Flooding events are a major contributor to natural disasters across the global tropics. However, reliable flood data are sparse, which limits our ability to understand flood dynamics across spatial and temporal scales. Here, data from the CYGNSS SmallSat constellation are utilized to identify small‐ to regional‐scale flooding events in Sumatra.
Zofia Baldysz, Dariusz B. Baranowski, Piotr J. Flatau, Maria K. Flatau, Clara Chew   +4 more
wiley   +1 more source

Near‐ground microwave radiometry for on‐the‐go surface soil moisture sensing in micro‐irrigated orchards in California

Agrosystems, Geosciences &Environment, Volume 8, Issue 3, September 2025.
Abstract High‐resolution geospatial soil moisture measurements are needed to inform hydrological modeling and to guide water management in agriculture, especially in highly heterogeneous systems such as micro‐irrigated orchards. In this research, we used a Portable L‐band Radiometer (PoLRa) to map very high‐resolution (<2 m) soil surface moisture in ...
Elia Scudiero, Amninder Singh, Gopal R. Mahajan, Dimitrios Chatziparaschis, Jayanta Banik, Konstantinos Karydis, Derek A. Houtz, Todd H. Skaggs   +7 more
wiley   +1 more source

Analysis of GNSS Interference Events Based on TRITON GNSS-R Measurements

Navigation
Although the issue of global navigation satellite system (GNSS) interference has been addressed in the community of satellite navigation, the extent of GNSS interference in the past couple of years has raised serious concerns for air and marine ...
Jyh-Ching Juang, Yung-Fu Tsai
doaj   +1 more source

A Special Collection on Hydrogeodesy in a New Era of Satellites for Better Understanding and Management of Water Resources

Water Resources Research, Volume 61, Issue 9, September 2025.
Abstract Hydrogeodesy is the discipline that measures the Earth's solid and aquatic surfaces and gravity field from space to study water resources and their changes over time. The Special Collections on Hydrogeodesy: Understanding Changes in Water Resources Using Space Geodetic Observations, in Water Resources Research (WRR) and Geophysical Research ...
Fernando Jaramillo, Fabrice Papa, Jida Wang, Shimon Wdowinski, Georgia Destouni, James Famiglietti   +5 more
wiley   +1 more source

Regional Land Surface Conditions Developed Using the High‐Resolution Land Data Assimilation System: Challenges Over Complex Orography Himalayan Region

Meteorological Applications, Volume 32, Issue 4, July/August 2025.
High‐resolution land data assimilation system (HRLDAS) simulations at 2 km resolution from 2011 to 2021 over Uttarakhand. HRLDAS outperforms global and regional analyses by capturing finer spatial heterogeneity, with lower soil moisture error and high soil temperature correlation (0.94) against satellite and in situ observations.
Buri Vinodhkumar, Krishna Kishore Osuri, A. P. Dimri, Sandipan Mukherjee, Sami G. Al‐Ghamdi, Dev Niyogi   +5 more
wiley   +1 more source