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"
}