Beam selection optimization algorithm for the Satcube Ku.
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Wireless, photonics and space engineering (MPWPS), MSc
Publicerad
2023
Författare
Olsson, Lucas
Saber, Pouria
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The Satcube Ku is a satellite terminal which provides internet access to a user
anywhere on Earth with the help of spot beam technology. For a given position
on Earth, multiple intersecting beams will be present with varying signal strength.
There is the need to distinguish one beam from another in order establish a hierarchy.
The purpose of this master thesis is to investigate a way to rank the available beams
at a position on Earth and develop that into a new beam selection algorithm for the
Satcube Ku terminal. The new algorithm must address both circular and elliptical
HTS-beams as the beams are projected across the surface of the Earth.
There are many limitations to this project and many different approaches have been
presented. The approach is to analyze user data and geospatial data combined with
provided satellite information in order to find important aspects of the problem. A
five step algorithm was ultimately decided. The algorithm takes the user position
as an input and gives a sorted list from highest to lowest carrier-to-noise expected
in that position as output.
The steps are: Step 1: Position and all available beams, Step 2: Beamcenter of
beams, Step 3: CNR value at beamcenter, Step 4: CNR reduction to the user posi tion, Step 5: CNR arranged list based on projection and accuracy. The step 1 was
solved using polygon conversion of the beam contours given by the terminal and
then calculating which polygons the user was inside of. In step 2 the beamcenter
of the beams were estimated by measuring the distance from the polygon center to
a beam center position provided by Intelsat for certain beams. In step 3 the each
beamcenter was given a maximum theoretical value also provided by Intelsat. In
step 4 three different methods were investigated to project what the received CNR
would be at the user position. The methods were Concentric Contour Contraction,
Concentric Elliptical Expansion and Least square fit method. The Concentric El liptical expansion was the most appropriate method available and was used in step
5 for a test position in Gothenburg.
The resulting output was limited to only IS33 and IS37 satellites due to the lack of
information regarding the beam center values. The final list projections compared
to actual measurements performed within 1 dB.
Beskrivning
Ämne/nyckelord
Satellite communication, Algorithm, Python, Data analysis, High-throughput satellite, Satcube Ku