The MegaPrime/MegaCam is the largest instrument ever built for CFHT since the telescope was built in the late 70s. It was a very ambitious and complex project that involved many institutions and companies in France and Canada. The idea was to develop an instrumental facility capable of sampling Mauna Kea superb image quality over a full square degree. After facing some image quality problems during the first 18 months, the instrument delivers since December 2004 pristine image quality throughout the entire field of view (e.g. 98% of the image quality falls within a 0.05 arcsec. range on a 0.5 arcsec. image!).

Programming the CFHTLS with its own set of contraints along with all the other normal Principal Investigator programs turned out to be a complex endeavor. The time constraints within the CFHTLS make it difficult to keep a even balance between the components.

The highest priority for QSO is to keep the balancing of the agencies on track throughout the semester. The CFHTLS is considered as an agency and the internal programming of the various components falls on the coordinators' shoulders.

The recipes developed for the CFH12K mosaic were optimized for MegaCam and high quality pre-processed, photometrically and astrometrically calibrated, data are available at CADC for download. These initial recipes however show some limitations for correcting the fringes on some z' band frames. A new global data release using new recipes is planned for mid-2006.

Elixir does not only pre-process the images, it also derives an astrometric solution for each image and derives photometric zero points for the various filters on a given observing run. Elixir, QSO and DADS combine their data to produce the MetaData, an extra set of information defining precisely the conditions in which the exposure was obtained.

CFHT is now equiped with a solid collection of machines that allow us to sustain a 3 minutes processing time per image. A high degree of automation allows us to carry through the data distribution with the limited manpower available.

See the page "Data Flow" in the "CFHTLS Data Products" section of this site.