Using Star Identification Algorithms on ESTCube-2 Star Tracker
Date
2019
Authors
Journal Title
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Publisher
Tartu Ülikool
Abstract
This thesis estimates the feasibility and determines the expected performance characteristics of
a star tracker for ESTCube-2 student satellite. It measures limiting magnitude for the ESTCube-
2 star tracker hardware and estimates the decrease in signal-to-noise ratio due to the spacecraft’s
rotational motion using geometric modelling. The acquired limiting magnitude is used to determine
the optimal parameters to use with the pattern recognition algorithms for star identification
purposes. The work also develops a way of creating and structuring a reference database
in an effective way.
Test results indicate that using the acquired parameters, the star tracker will be able to determine
spacecraft’s attitude for cases of slow rotation up to 5 degrees per second. Results also indicate
capability of attitude determination up to 10 times per second. The spacecraft’s mission also
contains a phase of fast rotation, during which the star tracker will no longer be able to produce
accurate attitude estimates at all times. With the algorithm configurations recommended in
the thesis the ESTCube-2 star tracker could still provide a valuable contribution to the attitude
and orbital control subsystem while experiencing angular velocities greater than 5 degrees per
second. Thus it may outperform state-of-the-art commercial nanosatellite star trackers in that
particular situation.
Description
Keywords
asendituvastus, nanosatelliidid, tähejälgimiskaamera, algoritmid, attitude determination, nanosatellites, star tracker, algorithms