Lecturer: Ariel Baron, MSc student, under the supervision of Prof. Pini Gurfil (AE) and Dr. Hector Rotstein (EE)
Location: Classroom 165, ground floor, Library, Aerospace Eng., January 30, 2023
Zoom: click here
Affiliation: Department of Aerospace Engineering
Institute: Technion – Israel Institute of Technology
Seminar Language: The talk will be given in English
Abstract:
In a GNSS-denied environment, it is important to have alternative navigation systems that can provide accurate and reliable positioning, navigation, and timing (PNT) information. This is particularly critical in scenarios where PNT is essential for safety or mission-critical applications, such as in aviation, maritime navigation, and military operations.
This research aims to develop a 4D (position/navigation/time) system by passively receiving downlink signals from large constellations of low Earth orbit satellites, such as OneWeb, Starlink, and GlobalStar. These constellations will not support pseudorange-based navigation because they will not carry atomic clocks and will not broadcast down link signals that support pseudorange measurements. Instead, the system will use carrier Doppler shift as the only navigation observable, using eight or more measurements to determine 3D position, receiver clock offset, velocity, and receiver clock offset rate.
The research focused on a Doppler shift measurement model. Convergence techniques for non-linear optimization were explored and the expected accuracy was evaluated through the development of Geometric Dilution of Precision(GDOP) formulations. A simulator was developed to assess navigation performance in static environments and predictGDOP at any given time and receiver location. Additionally, the research included a hardware implementation on a smart phone device as well as investigation into the effect of atmospheric and orbital errors on the navigation system.
Comments: Light refreshments will be served before the lecture
