1. The Footprint Database and Web Services of the Herschel Space Observatory
- Author
-
Kiss, Csaba, Budavári, Tamás, Valtchanov, Ivan, Exter, Katrina, Teyssier, David, Verdugo, Eva, Varga-Verebélyi, Erika, and Dobos, László
- Subjects
FOS: Computer and information sciences ,Computer science ,media_common.quotation_subject ,FOS: Physical sciences ,02 engineering and technology ,Virtual observatory ,USable ,computer.software_genre ,01 natural sciences ,law.invention ,Telescope ,Computer Science - Databases ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,computer.programming_language ,media_common ,Database ,Search engine indexing ,bepress|Physical Sciences and Mathematics|Computer Sciences ,Databases (cs.DB) ,Astronomy and Astrophysics ,Python (programming language) ,Visualization ,Space and Planetary Science ,Sky ,020201 artificial intelligence & image processing ,Web service ,Astrophysics - Instrumentation and Methods for Astrophysics ,computer - Abstract
Data from the Herschel Space Observatory is freely available to the public but no uniformly processed catalogue of the observations has been published so far. To date, the Herschel Science Archive does not contain the exact sky coverage (footprint) of individual observations and supports search for measurements based on bounding circles only. Drawing on previous experience in implementing footprint databases, we built the Herschel Footprint Database and Web Services for the Herschel Space Observatory to provide efficient search capabilities for typical astronomical queries. The database was designed with the following main goals in mind: (a) provide a unified data model for meta-data of all instruments and observational modes, (b) quickly find observations covering a selected object and its neighbourhood, (c) quickly find every observation in a larger area of the sky, (d) allow for finding solar system objects crossing observation fields. As a first step, we developed a unified data model of observations of all three Herschel instruments for all pointing and instrument modes. Then, using telescope pointing information and observational meta-data, we compiled a database of footprints. As opposed to methods using pixellation of the sphere, we represent sky coverage in an exact geometric form allowing for precise area calculations. For easier handling of Herschel observation footprints with rather complex shapes, two algorithms were implemented to reduce the outline. Furthermore, a new visualisation tool to plot footprints with various spherical projections was developed. Indexing of the footprints using Hierarchical Triangular Mesh makes it possible to quickly find observations based on sky coverage, time and meta-data. The database is accessible via a web site (http://herschel.vo.elte.hu) and also as a set of REST web service functions., Accepted for publication in Experimental Astronomy
- Published
- 2016