Bachelor's degree theses

Radio science experiments and precise orbit determination for deep space missions rely on microwave links (Doppler and Range) that are sensitive to the propagation medium. One of the primary sources of error is the Earth's ionosphere, a dispersive medium that introduces a frequency-dependent delay. To achieve the required accuracy for missions like Hera, BepiColombo or Juno, this effect must be modeled and removed. While the standard operational procedure relies on CSP files provided by JPL, these are not always available for all mission phases or ground stations. In such cases, Global Ionospheric Maps (GIM), provided by agencies like JPL in formats such as IONEX (e.g., JPLG, JPLD), serve as the primary alternative to estimate the Total Electron Content (TEC) along the spacecraft's line of sight.

Objective:
The goal of this thesis is to develop a tool to generate ionospheric delay calibrations using different Global Ionospheric Maps (GIM) and compare the results with official JPL-CSP calibration files. The candidate will analyze how different map products and interpolation strategies affect the computed delay, evaluating the impact on the radiometric observables used in radio science experiments.
 
Tasks:
- Study of Ionospheric Effects: Understand the physics of ionospheric delay, the concept of Total Electron Content (TEC), and the dependence of the dispersive delay.
- Data Acquisition: Retrieve IONEX files (Global Ionospheric Maps) from JPL servers and the corresponding official CSP files for a specific mission period.
- Algorithm Development: Implement a tool to:
    -Map the TEC from the IONEX grid to the spacecraft's line of sight.
    -Compute the delay for specific ground station-spacecraft links.
- Validation and Comparison: Perform a statistical comparison between the custom-generated calibrations and the official JPL CSP files, identifying discrepancies and the influence of different map types.
 
Requirements:
- Basic understanding of physics and signal propagation.
- Familiarity with Python or MATLAB for data analysis and visualization.
- Interest in space mission operations and data analysis.

Tutor: Edoardo Gramigna
Topic: Media calibration, Ionosphere delay
Uploaded: 03/03/2026

Some icy moons of the outer Solar System, such as Europa and Enceladus, host plasma environments produced by the interaction between a tenuous atmosphere, cryovolcanic plumes, and magnetospheric plasma. These environments can affect the propagation of radio signals transmitted by a spacecraft. When a radio signal passes through a region containing free electrons, its frequency undergoes a small but measurable variation (plasma-induced Doppler shift). This effect is the basis of radio occultation experiments used in space missions to study planetary atmospheres and ionospheres. Understanding the expected signal arising from the presence of an ionosphere or a plume is essential to assess whether such structures can be detected with onboard radio instruments and to determine the measurement accuracy required to characterize them.

Thesis Objectives
The objective of this thesis is to develop a simplified numerical model of the plasma environment around an icy moon in order to estimate the expected Doppler signal during radio occultation experiments. In particular, the student will build a simple model of the ionosphere and potential plumes and use it to estimate how the presence of free electrons along the radio signal path modifies the frequency observed on Earth. The model will then be used to explore different observation geometries and to assess the level of radio measurement precision required to detect and characterize such structures.

Expected Results
The thesis will lead to the development of a simple numerical tool for simulating the Doppler signal produced by ionospheres and plumes of icy moons during radio occultation experiments. The results will include simulations of the expected signal for different geometric configurations and a quantitative estimate of the sensitivity required for radio instruments to detect and characterize these structures. The work may also provide useful insights for more advanced studies on the interpretation of radio occultations in complex plasma environments.

Tutor: Matteo Fonsetti
Topic: Radio Science, Plasma Physics, Numerical Methods
Uploaded: 17/03/2026

Radio science experiments and precise orbit determination for deep space missions rely on microwave links (Doppler and Range) between spacecraft and ground stations. The signals propagate through the Earth’s atmosphere, where the troposphere introduces a non-dispersive delay that affects the accuracy of the measurements. This delay is commonly divided into a hydrostatic (dry) and a wet component. The hydrostatic component represents the largest fraction of the total tropospheric delay and is typically modeled using empirical formulations based on surface pressure measurements and atmospheric models. However, ground-based water vapor radiometers (WVR) provide direct measurements of atmospheric emission that can be used to estimate tropospheric delays more realistically. Comparing the Zenith Hydrostatic Delay (ZHD) computed through mathematical models with the values retrieved from radiometer measurements can help quantify modeling errors and assess their influence on orbit determination accuracy. Understanding these differences is particularly important for high-precision navigation and radio science experiments for missions such as Hera, BepiColombo, or Juno.

Objective
The goal of this thesis is to analyze and compare the Zenith Hydrostatic Delay (ZHD) estimated through standard atmospheric models with the delay retrieved from radiometer measurements, and to evaluate how the differences propagate into the orbit determination (OD) process. The candidate will investigate the consistency between the two approaches and quantify the impact of hydrostatic delay mismodeling on radiometric observables used in deep space navigation.

Tasks
- Study of tropospheric effects: understand the physics of tropospheric signal propagation, focusing on the separation between hydrostatic and wet components of the delay and their influence on microwave tracking observables;
- Data acquisition & analysis: retrieve radiometer’s measurements of zenith hydrostatic delay. Retrieve meteorological data (pressure, temperature, humidity) to compute the ZHD applying standard models;
- Impact on Orbit Determination: evaluate the differences between the two different ZHD measurements and their impact on the orbit determination process.

Requirements
- Basic understanding of atmospheric physics and signal propagation;
- Familiarity with Python or MATLAB for numerical analysis and visualization;
- Interest in space navigation, radio science, and atmospheric calibration techniques.

Tutor: David Bernacchia
Topic: Media calibration, Tropospheric delay, Orbit determination
Uploaded: 17/03/2026

Radio science experiments for deep space missions rely on highly stable microwave links between spacecraft and Earth-based ground stations. Among the different radiometric observables, Doppler measurements are particularly sensitive to propagation effects along the signal path. When the radio signal travels through the interplanetary medium, fluctuations in the electron density of the solar plasma introduce phase perturbations that manifest as additional noise in the Doppler observable. The resulting effects include phase scintillation and stochastic Doppler noise, which can degrade the quality of radio science measurements. Understanding the characteristics of this noise is important for properly interpreting Doppler data collected during such conditions. The long-duration radiometric dataset from the NASA mission Juno provides an excellent opportunity to study these effects across different solar elongation angles and solar activity conditions.

Objective
The goal of this thesis is to analyze the impact of solar plasma on Doppler radiometric measurements using tracking data from the Juno mission. The candidate will characterize plasma-induced noise affecting the Doppler observable and investigate how its statistical properties depend on the geometry of the observation and solar conditions.

Tasks
- Study of solar plasma effects: understand the physics of radio signal propagation through the solar corona and the interplanetary plasma, with particular focus on phase fluctuations and their impact on Doppler measurements;
- Data processing and analysis: develop analysis tools to collect plasma noise informations from Juno’s radiometric data and perform statistical analysis to determine the impact of solar plasma in Doppler measurements in terms of Allan deviation;
- Interpretation of results: compare the observed Doppler noise characteristics with theoretical expectations and previous studies of solar plasma effects on deep space radio signals.

Requirements
- Basic understanding of physics and electromagnetic signal propagation;
- Familiarity with Python or MATLAB for data analysis and visualization;
- Interest in space plasma physics and radio science experiments.

Tutor: David Bernacchia
Topic: Solar plasma effects, Doppler measurements, Plasma noise analysis
Uploaded: 17/03/2026