Intelligent detectors - On-board data reduction for future missions

Autor(en)

Roland Ottensamer, Ahmed Nabil Belbachir, Franz Kerschbaum

Abstrakt

The recent advances in IR detector technology to be operated in space having more channels and higher efficiency lead to scientifically more valuable data, but also to much higher data volumes and rates. So far, most scientific satellites have been able to downlink their plain raw data or have at least compressed them in a lossless manner using algorithms like Rice, but modern missions cannot do so any longer. Given the data rates of next-generation infrared detectors, the typical compression ratios of 2-3 and (in some cases maybe up to 5) are by far not sufficient to lead to reasonable downlink rates. Especially satellites with a very limited lifetime, such as in the IR, cannot afford lengthy downlink periods and must therefore reduce the data to the available amount. Considerations on feasibility and implementation of on-board reduction and compression concepts are given with respect to the PACS (Photodetector Array Camera and Spectrometer) instrument of the Herschel Space Observatory. PACS' on-board software features reduction steps that are usually performed on ground, such as glitch detection and ramp fitting. Experiences from Herschel/PACS can be well applied to subsequent projects with a need for adaptive on-board data processing. Furthermore, from instrument specific lossless compression to sophisticated wavelet transform methods, an overview shall be given about the importance and amount of effort in data reduction, which is a critical component for future instrumental design. Since the complexity of on-board software depends critically on the available processing power, the question for realistic hardware resources is also considered. The major consequence is, that future missions, which will have to conduct destructive reduction steps, will no longer provide raw data to the community, but at least partly reduced data products. Π2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Technische Universität Wien

Journal

Astronomische Nachrichten

Band

326

Seiten

582-583

Anzahl der Seiten

2

ISSN

0004-6337

Publikationsdatum

2005

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/36146b84-f76d-459b-ad85-cde4291688ad