Advanced Microwave Remote Sensing Technologies for Hydrology

Dear Colleagues,

Microwave remote sensing has emerged as a valuable tool for hydrological applications due to its numerous advantages, including all-weather and day-night capabilities, the ability to penetrate clouds and vegetation, and sensitivity to surface water properties like soil moisture and water content. The information obtained from microwave remote sensing plays a crucial role in various aspects of water resource management, flood forecasting, drought monitoring, and climate studies. Recent advancements in microwave remote sensing have further expanded its utility in hydrology. One notable development is the use of signal of opportunity, which repurposes existing microwave transmit signals to extract geophysical parameters from reflected signals. For instance, global navigation satellite systems-reflectometry (GNSS-R) is an emerging remote sensing technique that leverages navigation signals to map global soil moisture fields, vegetation characteristics, and has shown promise for applications such as tropical wetland mapping and operational flood mapping. Another significant mission is the Surface Water and Ocean Topography (SWOT) mission, successfully launched in 2022, which aims to measure river width, slope, water level, and discharge. The data from this mission will significantly improve our understanding of surface water dynamics. Moreover, advancements in passive radiometer technology have led to higher resolution, enabling its application in hydrology with increased accuracy.

Additionally, the progress in computational processing power and infrastructure, particularly with online cloud computing, has made high-performance computing accessible and affordable to a wide range of users. These developments have facilitated widespread access to hydrological data and analysis tools.

In alignment with the advancements mentioned above in microwave remote sensing technology for hydrological applications, this Special Issue aims to gather studies that utilize such data from diverse sources, including ground-based experiments, airborne data acquisition, and space-borne microwave satellite products. By leveraging the capabilities of microwave remote sensing, researchers have the opportunity to delve into various aspects of hydrology. In this context, we invite articles that address the following areas, but not restricted to:

• Soil moisture monitoring;
• Surface water monitoring;
• Snow depth and snow water equivalence estimation;
• Wetland monitoring;
• Groundwater monitoring;
• Precipitation estimation;
• Climate study;
• Data assimilation and modeling;
• Advancement in algorithms (data fusion, machine learning).

This Special Issue is directly relevant to the scope of the journal, with a particular focus on physical modeling and signatures, data assimilation, data fusion, and remote sensing applications, especially in the context of hydrology. The articles included in this issue will contribute to a deeper understanding of the physical processes, facilitate the assimilation of data into hydrological models, explore data fusion techniques, and demonstrate the practical applications of remote sensing technology in addressing hydrological challenges.

Dr. Xiaolan Xu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Remote Sensing is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• soil moisture
• snow water equivalence
• Surface Water and Ocean Topography (SWOT) mission
• GNSS -R
• SoOP (signals of opportunity)
• precipitation
• wetland
• machine learning
• SAR