Publication Details
Noise reduction in asteroid imaging using a miniaturized spectral imager
Denoising, Imaging systems, Asteroids, Signal to noise ratio, Image quality, Digital filtering, Hyperspectral imaging, Gaussian filters, Fabry-Perot interferometers
In October 2024, European Space Agencys Hera mission will be launched,
targeting the binary asteroid Didymos. Hera will host the Juventas and
Milani CubeSats, the first CubeSats to orbit close to a small celestial
body performing scientific and technological operations. The primary
scientific payload of the Milani CubeSat is the SWIR, NIR, and VIS
imaging spectrometer ASPECT. The Milani mission objectives include
mapping the global composition and the characterization of the binary
asteroid surface. Onboard data processing and evaluation steps will be
applied due to the limited data budget for the downlink to Earth and to
perform the technological demonstration of a novel semi-autonomous
hyperspectral imaging mission. Before downloading, the image data is
evaluated in terms of sharpness and coverage and processed by
compression. The challenges and their proposed solutions for the data
processing part of the mission are investigated through studies. Since
most noise contributors are unknown until Milani is activated, different
noises are studied based on previous missions and derived from
hyperspectral images taken in a laboratory environment mimicking the
real-life situation. The hyperspectral camera technology in the
laboratory is similar to the one used in the ASPECT imager payload. Both
ASPECT and the imagers utilized in our measurements are based on
employing a Fabry-Pérot interferometer as an adjustable transmission
filter. The imagers are also designed and built by the same party, the
Technical Research Centre of Finland (VTT). Best performing denoising
techniques for each noise type are discussed on the one hand for the
entire datacubes and on the other hand for the spatial domain only since
the mission includes images taken only at specific wavebands. The
advantage of applying denoising for the whole datacube comes from the
internal dependencies between the wavebands, allowing efficient
processing. A trade-off study for several noise reduction algorithms is
presented. The goal is to implement efficient image processing
algorithms with low computational complexity, securing the successful
execution of the mission.
@inproceedings{BUT175828,
author="WOLFMAYR, M. and KAŠPÁREK, T. and KOHOUT, T.",
title="Noise reduction in asteroid imaging using a miniaturized spectral imager",
booktitle="Proceedings Volume 11858, Sensors, Systems, and Next-Generation Satellites XXV; 118580P (2021)",
year="2021",
series="Proceedings of SPIE - The International Society for Optical Engineering",
volume="11858",
pages="1--13",
publisher="SPIE - the international society for optics and photonics",
address="-",
doi="10.1117/12.2600201",
isbn="978-1-5106-4560-8"
}