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Projecte llegit

Títol: Positioning with LEO satellites and software tool for satellite observation

Estudiants que han llegit aquest projecte:

Director/a: OLMOS BONAFÉ, JUAN JOSÉ

Departament: TSC

Títol: Positioning with LEO satellites and software tool for satellite observation

Data inici oferta: 08-03-2022     Data finalització oferta: 08-11-2022


Estudis d'assignació del projecte:
    DG ENG AERO/TELEMÀT
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
Satellite orbit, Keplerian elements, TLE, Software tool, Pointing angles, ECEF coordinates, LLA coordinates, Satellite visibility, Doppler, Kalman filter
 
Descripció del contingut i pla d'activitats:
Currently there are proposals from some companies to put thousands of satellites into the Low Earth Orbit (LEO satellites). This TFG proposal aims to create a software tool that allows to compute (and display in a user's friendly way) which satellites are visible from a specific location (on Earth surface) during an specific time window. The tool should also accept a satellite identifier and return the corresponding time window and pointing angles (azimuth and elevation) to view the satellite (or pointing the antenna) from the user location. It is also envisaged to compute the satellite signal Doppler shift (given the signal frequency) to facilitate the signal demodulation with the use of a software radio receiver. Knowing the Doppler frequency shift it possible to compute the receiver position (Lat.,long.) by means of the Kalman filter.
The data for orbit characterization (Two Line Elements, TLE) must be downloaded (programmatically) from the Celestrak web page (http://celestrak.com). That data is enough to compute the satellite ECEF coordinates at any given time. From the ECEF coordinates it's not difficult to predict the satellite visibility from any specific location on Earth. The student should first develop a Matlab script for testing ideas and algorithms and finally translate it into C# or C++ language. To obtain a user friendly application it is suggested to use the HTML plus JavaScript combination (using JQUERY graphs for example).
 
Overview (resum en anglès):
As the title indicates, the project is divided in two parts:

The first part of this document will explain the development of a LEO positioning system based on Iridium satellites. This system has been implemented in Matlab, and although different methods have been tried, the best results have been obtained with the Extended Kalman Filter. Despite this, there is still place for improvement.

The second part explains the development process of a software tool for satellite observation in the form of a web app called "Satellite Tracker". Specifically it is used for orbit visualization, for LEO satellites just as the Iridium and Starlink constellations or the ISS, and also for GPS satellites. This software also allows for the observation of the Doppler effect, that is produced by the movement of the satellite, and other real-time parameters, just as the user area visibility. His goal is to be useful specially for the students of the subject of Air Navigation, Cartography and Cosmography at EETAC, and also for other students around the world.

The used technologies, in the case of the frontend of the web app, are HTML, CSS, Bootstrap and Javascript, while for the backend, the framework Flask has been used which uses Python as a programming language. To store the necessary data, for the correct operation of the web app, a non-relational database such as MongoDB has been utilized.

Although, some improvements have been presented on both parts of the project, good results have been obtained and the initial goals have been accomplished.

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