Project Description

We provide several specializations project aims at exploring how Global Navigation Satellite System Reflectometry (GNSS-R) from a small satellite in a Low Earth Orbit (LEO) can enable solutions to several important challenges for maritime mapping, monitoring, and surveillance

The focus of this project will focus on alternative signals of opportunity for positioning navigation and timing applications based on LEO communication satellites signals such as Starlink.

Having access to an alternative PNT signals is highly beneficial considering the increasing GNSS malicious interference (jamming and spoofing) resent years. A potential future application is Ku-band (downlink signal band of Starlink) reflectometry. The potential added benefit is improving reflectometry compared to GNSS-R (see below). GNSS has 20+ satellites per constellation in medium Earth orbit while Starlink has a constellation over 7 000 (and increasing) satellites in LEO.

About Global Navigation Satellite System Reflectometry (GNSS-R)

GNSS-R operates as a bi-static radar using Earth-illuminating GNSS signals from GPS, GLONASS, Beidou, and Galileo satellites at around 20,000 km altitude. These signals, reflected off the Earth's surface and objects, can be measured by LEO satellite antenna receivers at about 600 km altitude. By installing an GNSS antenna on the zenith side and a GNSS-R antenna on the nadir side of the LEO satellites, 3D positioning of reflective points and analysis of surface in the glistering zone is possible.

Until recently, the primary remote sensing applications of spaceborne GNSS-R focus on the analysis of the sea-state (local wind speed, sea surface roughness, sea altimetry), soil moisture, biomass and vegetation estimation, sea-ice sheets analysis (height, volume, sea/ice index) and tsunami warning. An early study has also shown that oil spills can be detected. We will focus on the ability to detect and localize anomalies near the ocean surface. GNSS interference is also an option.

Impact
Space technology plays a crucial role in achieving various Sustainable Development Goals (SDGs) set by the UN. GNSS-R has the capability to be an all-weather, near real-time detection space-based surveillance system independent clouds and systems based on trust and self-reporting such as AIS. GNSS-R has the potential to allows us to detect and monitor water vessels at sea and localize GNSS inference sources originating from sea or land. This project target

Space technology plays a crucial role in achieving various Sustainable Development Goals (SDGs) set by the UN. GNSS-R has the capability to be an all-weather, near real-time detection space-based surveillance system independent clouds and systems based on trust and self-reporting such as AIS. In Norway, space has a crucial role to play in our collective security and monitoring of critical infrastructure and the Arctic region. GNSS-R has the potential to allows us to detect and monitor water vessels at sea and localize GNSS inference sources originating from sea or land. This project target

• SDG9 Industry, innovation, and infrastructure. The outcomes have an innovative and commercial potential for industry and can contribute both to new space-based infrastructure and protection of existing critical infrastructure beyond GNSS.

• SDG16 Peace, justice and strong institutions. Maritime surveillance and GNSS interference monitoring are both relevant for this.

Tasks and Expected Outcomes
The objective of the project is to investigate the PNT properties of Starlink based on [1]. See also the Institute of Navigation video abstract. The tasks may include

• To a short literature review on signal of opportunity PNT based on LEO communication satellite signals including [1].
• Investigate what equipment will be needed (antenna, SDR etc,) need to decode the Starlink signal
• Singal processing and Doppler tracking.
• Doppler positioning of an antenna based on the subtasks above.

Direct collaboration with other students working on GNSS-R related projects is possible. 

Who We Are Looking For
We are seeking a highly motivated final year student in Cybernetics, Electronics, or a related field with an interest either one or several of the topics

• positioning, navigation and timing (PNT) systems 
• signal processing
• estimation and localization

Experience from subjects such as TTK4150 Sensor Fusion and TTT4275 Estimation, detection and classification, in addition to TTT4150 Navigation systems, will be beneficial for the student in this project. Experience with signal processing techniques is not mandatory. The project will be adapted to the student's background and goals. 

How we work
The student will be part of the NTNU SmallSat lab, a lab which typically hosts 10-20 master's student per semester. At the NTNU SmallSat Lab we encourage collaboration and try to get our group to help each other. To facilitate this, we as well as arrange common lunches and workshops where the students and supervisors can learn from each other. I some project we also implement a development process.

Supervisor(s)
For further questions please contact:

• Torleiv H. Bryne(main supervisor, NTNU/ITK), Roger Birkeland (co-supervisor, NTNU/IES),
• Egil Eide (main supervisor, NTNU/IES), Roger Birkeland (co-supervisor, NTNU/IES).

References(s)
[1] Sharbel Kozhaya, Joe Saroufim, and Zaher (Zak) M. Kassas (2025), NAVIGATION: Journal of the Institute of Navigation March 2025, 72 (1) navi.685; DOI: https://doi.org/10.33012/navi.685