Overview
This project develops a novel method to detect small space debris by modelling how debris disturbs ionospheric plasma and how these disturbances can be used to extract debris parameters. While experimental capability will be established, the primary focus is on physics-based modelling and signal interpretation, in collaboration with the European Space Agency (ESA).
About this opportunity
Low Earth Orbit (LEO) is increasingly congested with space debris, particularly fragments smaller than 10 cm that cannot be tracked by conventional radar or optical systems, yet pose significant risk to satellites and future missions. Recent studies have shown that such debris, when travelling at orbital velocities through ionospheric plasma, generates disturbances such as plasma wakes and nonlinear wave structures (e.g. solitons), which can interact strongly with radio-frequency signals (DesJardin & Hartzell, 2023; Bernhardt et al., 2023). These effects offer a fundamentally new pathway for indirect debris detection.
This PhD project will develop a physics-based framework to model how space debris induces disturbances in ionospheric plasma, and how these disturbances can be exploited to infer key debris parameters such as size, velocity, and trajectory. The work will focus on two core areas: (1) forward modelling of plasma–debris interactions under realistic LEO conditions, and (2) inverse modelling and signal interpretation to extract debris characteristics from measured electromagnetic signatures. While an experimental platform will be established to support validation, the primary emphasis of the PhD is on modelling, simulation, and parameter extraction.
The candidate will develop and integrate models of plasma dynamics and electromagnetic wave propagation, drawing on nonlinear plasma theory and microwave/RF signal analysis. They will also explore data-driven approaches, including signal processing and machine learning, to distinguish debris-induced signatures from natural plasma variability. The project will utilise existing datasets from space missions (e.g. COSMIC-2, ESA Swarm) and simulated scenarios to validate detection strategies.
The student will receive interdisciplinary training in plasma physics, electromagnetic modelling, and advanced signal processing, with access to state-of-the-art facilities in RF and microwave engineering and plasma diagnostics at the University of Liverpool. The project is conducted in collaboration with the European Space Agency (ESA), providing opportunities for technical exchange, joint supervision, and research visits to ESA laboratories.
The PhD is structured to support progressive development of expertise. The first year will focus on foundational training, literature review, and initial model development. The second year will concentrate on advanced modelling, simulation, and preliminary validation. The final years will focus on inverse modelling, parameter extraction, system-level analysis, and thesis preparation, with increasing independence and opportunities for publication and international collaboration.
This project offers a unique opportunity to contribute to a high-impact, emerging area at the intersection of space engineering, plasma physics, and sensing technologies, addressing a critical challenge in the sustainability of the space environment.