SARWater

The first Progress Review Meeting of SarWater is due soon

2026-01-26T11:00:00Z

We are pleased to announce that the first Progress Review Meeting of the SarWater project will be held in Bari (Italy) on 26 March 2026.

During the meeting, we will present the results of the initial review of the key scientific questions related to the understanding of soil moisture and vegetation water content variables, as well as the review of the retrieval algorithms based on multi‑frequency SAR data. A central topic of discussion will be the plan for the validation of SARWATER products, which represents a crucial step toward ensuring their scientific robustness and operational relevance. In this context, the role of NISAR data in SARWATER - and its potential implications for the project plan - will also be addressed.

Look at the first detailed review paper on soil moisture remote sensing and AI!

2026-01-13T11:00:00Z

A new review article, provided by the Jülich team, gives a comprehensive look at the transformative role of Artificial Intelligence in monitoring one of the planet's most critical resources: soil moisture. Published in the International Journal of Applied Earth Observation and Geoinformation, the paper, titled "AI in Soil Moisture Remote Sensing," explores how AI is revolutionizing our ability to understand and manage a key component of the global water cycle.

Soil moisture is a vital variable for everything from agricultural planning and drought monitoring to climate change research. However, accurately measuring it at a global scale has been a persistent challenge. This review highlights how AI techniques are uniquely positioned to overcome the limitations of traditional methods. By discerning complex, data-driven relationships without prior assumptions, AI can significantly improve:

Time series reconstruction
Root zone soil moisture estimation
Spatial scaling and forecasting

The authors describe the current state-of-the-art as a "transformative era" and lay out a roadmap for future research. They emphasize the need to move beyond simply applying AI, towards creating hybrid systems where AI and physical models work in tandem.Key recommendations from the publication include: Embracing Hybrid Models: Combining data-driven AI with physics-based models to ensure results are not just accurate, but also explainable and consistent with scientific laws. Fostering Interdisciplinary Teams: Bringing together remote sensing scientists, data scientists, sensor engineers, and end-users to solve complex challenges and correctly interpret results.

Keeping Pace with Innovation: Harnessing the latest advancements in AI, such as foundation models and generative approaches, to unlock new insights from vast amounts of Earth observation data.

You can access the full publication here: DOI:10.1016/j.jag.2025.10501

SARWater website published

2025-12-18T15:43:00Z

Today, the very first version of the SARWater website has been published for general consumption, including some pending news and general information about the project. RSS feeding is available for subscriptions, with also by-topic sub-sectioning.

Here are some details on the implementation of such a system and its coding, for the most technically inclined readers.

The first publication for the SARWater project

2025-11-27T10:00:00Z

We are proud to announce the first publication funding from the European Space Agency for the SARWATER project! The paper highlights the remarkable progress in soil moisture retrieval achieved through the Sentinel-1 mission and explores exciting prospects for future advancements.

It discusses the application of C-band SAR observations from the Sentinel-1 satellite mission to estimate high-resolution near-surface soil moisture. First, the importance of SAR backscatter monitoring from Sentinel-1 is emphasized. Factors such as the effects of vegetation and surface roughness on the signal, sensor and scattering model limitations, spatial and temporal constraints, and uncertainties, e.g. in data assimilation, pose challenges to its usage. While Artificial Intelligence (AI)-based retrieval methods have shown promise, their interpretability, dependence on large datasets, vulnerability to data quality, and computational burden have been major challenges.

Beyond methods that rely on backscatter, there have been recent works indicating that SAR interferometric observables have the potential to estimate soil moisture, especially in arid and semi-arid regions where these are particularly sensitive to moisture changes. To address these challenges, this paper recommends integrating Sentinel-1 with other satellite mission data for a multi-sensor data integration approach (e.g., Sentinel-2 and Soil Moisture Active Passive - SMAP data), refining physical and semi-empirical models, developing advanced AI techniques able to consider physical principles, and combining with emerging data from other high temporal resolution SAR missions (e.g., NASA-ISRO SAR).

The review concludes with the identification of key research priorities, including the standardization of retrieval frameworks, improved validation efforts on standardized reference sets, and cloud processing for real-time user cases. Overall, the review provides a thorough foundation for understanding, refining, and advancing Sentinel-1 based soil moisture retrieval methods.

Enjoy the reading! DOI:10.1016/j.rse.2025.115146

SARWater at AIT International Conference 2025

2025-11-15T15:00:00Z

SARWater was presented during the Remote sensing of high resolution soil moisture and irrigation applications special session of the XII AIT International Conference, on 12-13-14 November, in Milan.

The presentation highlighted the key scientific challenges for high-resolution (0.1–1.0 km) retrieval of surface soil moisture and vegetation water content from multi-frequency Synthetic Aperture Radar (SAR), and the strategies adopted within the project to overcome them. Preliminary findings from multifrequency SAR datasets acquired over the Apulian Tavoliere in Italy and the Rur catchment in Germany were shown, demonstrating the potential of SARWATER’s approach.

Researchers, professionals, institutional players, and students in remote sensing were involved in the conference and attended the session.

Find more, here

SARWater project kick-off

2025-09-23T15:00:00Z

We are excited to announce that the SAR retrieval of soil and vegetation water content (SARWATER) project kicked off today, the 23rd of September 2025 at ESA ESRIN. SARWATER project responds to the call ESA CfP/5-50086/24/I-DT-bgh, Sentinel User Preparation (SUP) in SAR – Fundamental Scientific Developments (SUPSAR) and will last two years.

The goal of the study is to develop advanced retrieval algorithms for surface soil moisture and vegetation water content at high spatial resolution (~250 m), using multi-mission SAR data at C- and L-band data. A key component of the study is to demonstrate and assess the impacts of the newly developed SARWATER products for hydrological and agricultural applications, i.e. the improvements of root zone moisture and evaporation estimates and the detection and quantification of irrigation extent.

During the meeting, the project partners, CNR-IREA, FJG and UGent illustrated and discussed the activities foreseen in the project. The final prototype products fully validated as well as the demonstration products will be made available to the scientific community.

Stay tuned!