Montage An On Demand Image Mosaic Service for the NVO

Montage will deliver a generalized toolkit for generating on demand science grade custom astronomical image mosaics Science grade in this context requires that terrestrial and instrumental features are removed from images in a way that can be described quantitatively Custom refers to user speci ed parameters of projection coordinates size rotation and spatial sampling and whether the drizzle algorithm should be invoked The greatest value of Montage will be its ability to analyze images at multiple wavelengths by delivering them on a com mon projection coordinate system and spatial sampling and thereby al lowing analysis as if they were part of the same multi wavelength image Montage will be deployed as a compute intensive service through exist ing portals It will be integrated into the emerging NVO architecture and run operationally on the Teragrid where it will process the MASS DPOSS and SDSS image collections The software will also be portable and publicly available Introduction What Is Montage Montage is an astronomical image mosaic service It will deliver science grade custom image mosaics according to input speci cations of size WCS projection coordinate system image rotation spatial sampling and background removal Science grade in this context has two de nitions Montage will preserve the astrometric and photometric accuracy of the input images and it will perform background recti cation on the input images in such a fashion that its impact on the photometric quality of the data can be described quantitatively The principal science goal of Montage is to extend the mosaicking capabili ties available to astronomers by supporting the production of multi wavelength images That is images from diverse sources over many wavelengths can be combined into mosaics having common coordinates WCS projection spatial sampling size and image rotation Such mosaics are requisite for analysis tasks such as multi wavelength source extraction and band merging The SIRTF Wide Area Infrared Experiment SWIRE has adopted Montage to support analysis of multi wavelength images of deep SIRTF infrared images and ground based optical and radio images Schedules and Platforms The Montage software will be publicly available through the project website at http montage ipac caltech edu Montage will be designed and devel oped as a portable software package written in ANSI C and supported under current plans on Solaris and Linux x and x and AIX It will be de livered incrementally at roughly six monthly intervals between February and January Early deliveries will emphasize delivery of astromerically and photometrically accurate science grade mosaics while later ones will emphasize speed and throughput On nal delivery Montage will achieve a throughput of square degrees e g thirty degree x degree mosaics or one degrees x degrees mosaic etc per minute on a x MHz R K Processor Origin or machine equivalent with sustained bandwidth to disk of MB sec In August Montage will be deployed as an operational service through the National Virtual Observatory NVO http www us vo org Users will then order mosaics through existing astronomy portals with the calculations performed on the Distributed Terascale Facility http www teragrid org a high performance computational grid provided by the NSF Partnership for Advanced Computational Infrastructure When fully deployed the Teragrid will provide aggregate computational power on the order of Tera ops aggregate disk cache on the order of TB and archival storage capacity of Petabytes