Abstract
PERICLES (Promoting and Enhancing Reuse of Information throughout the Content Lifecycle taking account of Evolving Semantics) is a four year EU FP7 integrated project on digital preservation that began in February 2013. PERICLES aims to ensure the ongoing accessibility of digital material in a constantly changing environment. The project focuses on two case studies, one from space science and the other from digital media and art. Through communities of practice, the project is also exploring how these specific studies can be generalised across a wider set of domains. The space science case study is based on the SOLAR experiment, which generates raw observations of the spectrum of the sun, using
instruments based on the International Space Station (ISS). This raw data are analysed and calibrated by a team of scientists using a complex set of scripts. Calibration is an iterative process running over a number of years. Increased understanding of the behaviour of the instruments and phenomena which may bias the observations (e.g. arrival of vehicles at the ISS) mean that previous calibrations need to be recomputed.
The software platforms on which the data gathering and processing are performed are themselves subject to change. Results obtained from SOLAR are also compared to observations made using different instruments, which are generally based on different technologies. The long duration of the SOLAR
experiment, the need to continuously review and reprocess previous results, and the ongoing evolution of software platforms collectively pose a critical challenge for traditional end-of-life preservation approaches. In this respect, the boundary between active life and end-of-life is not clearly defined. We instead apply a continuum approach where preservation tasks such as appraisal and policy management are much more integrated into active life. The paper will consider two specific issues: Appraisal of experiments, where newer calibrations are compared with older results, and some results are marked as less accurate or reliable; Technology change such as updates to software platforms. For example, a new version of a maths library may increase the accuracy of a data analysis operation. It may consequentially bedesirable to refactor older calibration results to take advantage of this.
instruments based on the International Space Station (ISS). This raw data are analysed and calibrated by a team of scientists using a complex set of scripts. Calibration is an iterative process running over a number of years. Increased understanding of the behaviour of the instruments and phenomena which may bias the observations (e.g. arrival of vehicles at the ISS) mean that previous calibrations need to be recomputed.
The software platforms on which the data gathering and processing are performed are themselves subject to change. Results obtained from SOLAR are also compared to observations made using different instruments, which are generally based on different technologies. The long duration of the SOLAR
experiment, the need to continuously review and reprocess previous results, and the ongoing evolution of software platforms collectively pose a critical challenge for traditional end-of-life preservation approaches. In this respect, the boundary between active life and end-of-life is not clearly defined. We instead apply a continuum approach where preservation tasks such as appraisal and policy management are much more integrated into active life. The paper will consider two specific issues: Appraisal of experiments, where newer calibrations are compared with older results, and some results are marked as less accurate or reliable; Technology change such as updates to software platforms. For example, a new version of a maths library may increase the accuracy of a data analysis operation. It may consequentially bedesirable to refactor older calibration results to take advantage of this.
Original language | English |
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Title of host publication | Proceedings of PV 2015 |
Publisher | EUMETSAT |
Publication status | Published - 2015 |
Keywords
- digital preservation
- space science
- SOLAR experiment