Monday 30.01.2023 | 13:30
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.
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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 andreliable positioning, navigation, and timing (PNT) information. This is particularly critical in scenarios where PNT isessential 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 fromlarge constellations of low Earth orbit satellites, such as OneWeb, Starlink, and GlobalStar. These constellations willnot support pseudorange-based navigation because they will not carry atomic clocks and will not broadcast downlinksignals that support pseudorange measurements. Instead, the system will use carrier Doppler shift as the onlynavigation observable, using eight or more measurements to determine 3D position, receiver clock offset, velocity, andreceiver clock offset rate.
The research focused on a Doppler shift measurement model. Convergence techniques for non-linear optimizationwere 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 asmartphone 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