Researcher | Geospatial Data scientist | Microwave data | Remote sensing for Agriculture Intelligence |Certified AI/ML Professional
1mo • Edited
I defended my PhD.
After almost 3 and a half years at Surrey Space Centre, my thesis, “Physics-Informed Multi-Frequency SAR for Depth-Resolved Soil Moisture Retrieval”, has passed, subject to corrections. It asks a deceptively simple question: can radar tell us not just whether soil is wet, but how that moisture is distributed with depth? Across three studies on two continents, I found some answers and a great many more questions.
Thank you to my supervisors, Raffaella Guida and Max Kerslake, for years of patience and sharp questions. Raffaella, thank you for being at every field visit and every collaboration meeting, for the expertise you brought to all of it, and for backing the ideas that went beyond the thesis. You let the research stay mine and made it better.
And thank you to my examiners, Carsten Montzka, Professor Craig Underwood and Nicola Baresi, for a viva that was genuinely enjoyable.
None of the validation work would exist without the people who let me onto their land and into their data. David Wolfe at Wakelyns Agroforestry in Suffolk, thank you for the site access and for teaching me more about agroforestry in one afternoon than I’d got from a year of papers. @Luca Ferrian and Athira Anand Nair, thank you for all the help with site activities and for the long days in the field. Hassan Dashtian at University of Texas, Austin, thank you for opening up TxSON and for the collaboration that followed. Thank you also to @Stephen Williams and Delta-T Devices, whose probes carried the soil moisture measurements, and who answered every technical question quickly and properly.
The photos say it better than I can. Very little of a PhD happens at a desk, and almost none of the good parts do. Thank you to everyone who helped and supported me along the way, and to all my colleagues at Surrey Space Centre.
And here’s the backstory:
In June 2024, a research team from the Surrey Space Centre (SSC), University of Surrey, initiated an important study at Wakelyns. The project is led by PhD student Catherin Sebastian under the supervision of Dr. Raffaella Guida, with contributions from Master student Athira Anand Nair and the SSC technician Luca Ferrian. The objective of the research is to develop and validate a satellite-based methodology for measuring soil moisture at different depths in the soil (up to 1m), which have significant implications for agriculture and environmental science.
From left Luca Ferrian, Dr. Raffaella Guida, Catherin Sebastian and Athira Nair
The team leverages on 12-year long experience, started in preparation for the first UK spaceborne radar mission NovaSAR-1, of combining satellite data for nearly real-time measurements of soil moistures over large areas. The new field campaign in Wakelyns has been organized to collect ground truth that could be used to validate an innovative methodology, based on multi-frequency radar data, to estimate the vertical profile of soil moisture. To verify and complement satellite measurements, the researchers have installed at Wakelyns a meter-long probe that measures soil moisture at different depths. The information is recorded hourly in a data logger.
By integrating satellite observations with on-site measurements, the team can measure soil moisture levels whenever radar satellite coverage is available. This information is valuable for farmers, enabling them to optimize irrigation practices, which promotes both crop health and water conservation.
Wakelyns is particularly suitable for this study due to its long-standing practice of agroforestry – growing trees and crops together – which it has maintained since 1992. Agroforestry systems are known for their effectiveness in storing carbon in the soil.
Recent studies have been exploring the relationship between soil moisture and carbon storage. There’s growing interest in carbon sequestration – the process of capturing and storing atmospheric carbon dioxide in the soil – as a potential strategy to mitigate climate change.
By studying soil moisture at Wakelyns, the project aims to contribute to our understanding of how soil water content may influence carbon storage. This research could provide insights into developing farming practices that are both productive and environmentally beneficial.
This project is part of a broader effort to develop agricultural methods that balance crop productivity, water efficiency, and environmental sustainability. It demonstrates how advanced technology and innovative farming practices can address contemporary agricultural and environmental challenges.
The study is designed as a long-term project. The research team will return to Wakelyns every 3-4 months to collect the accumulated data, ensuring a comprehensive and continuous dataset for their analysis.
