CFHT Legacy Survey Data Access Policy


The set of rules defining the CFHTLS data access policy has been established by the CFHT Board of Directors at its December 2002 meeting. The corresponding document is given hereafter. Some of these rules could change over the duration of the CFHTLS. This page will be updated accordingly.

Note: This page replaces an earlier set of rules established by the CFHT Board of Directors at its December 2001 meeting. Changes were only made on items 4 to 8.

CFHT Board of Directors - December 2002

1. The CFHTLS is based on the concept that all members of the CFHTLS community (defined below) have equal access to the raw and pre-processed images obtained at the telescope and to the subsequent advanced data products produced by the Terapix and CADC processing centers (collectively referred to as the CFHTLS data).  Access will be via registration as a Registered User (defined below).

2. The raw and pre-processed images, and later the advanced data products, will be made available to all Registered Users simultaneously. Individuals responsible for pre-processing and releasing the CFHTLS images will not undertake science analysis in advance of the release to the CFHTLS communities.

3. The CADC shall serve as the primary distribution center that provides general community access to the data.  The CFHT and Terapix may retain private copies of locally produced data for use by their respective scientific staff. Such private data will be identical to that provided to the community through the CADC, and will not to be distributed outside these institutions.

4. The standard image data available for general community distribution will be the pre-processed images produced by the CFHT-NOP data system. Unprocessed (raw) images will also be made available to the CFHTLS community as soon as possible after delivery to the CADC. Release of the pre-processed data will occur as soon as possible after observations and it is anticipated that there will be a release of all of the data from an observing run no later than one month after the run.

5. The first public access to CFHTLS data through the CADC will occur 3 years after the start of the survey and will include the first year of raw and pre-processed data. Access to the second year of CFHTLS data will occur 6 months later. Subsequent data access will occur on a monthly basis, one year after the date of acquisition.

6. Public access to the CFHTLS advanced data products (e.g., catalogues, optimally processed and stacked images) will be made through well defined, scheduled releases. The first such release will occur 3 years after the start of the survey to coincide with the first public access to raw and pre-processed CFHTLS data. The final release of advanced products will occur no later than one year after the end of the Survey.

7. Registered Users agree to protect the proprietary rights of the CFHTLS community by individually not exporting proprietary images to persons other than Registered Users or of making public the data in digital form.

8. Scientific collaborations that make use of CFHTLS data are encouraged. However, the export of CFHTLS proprietary images to external members of a scientific collaboration is permitted only upon the explicit authorization from the CFHT Executive Director, upon advice from the CFHTLS Science Steering Group.

9. The results from all scientific analyses of CFHTLS data are the exclusive property of the individuals responsible for the analyses and may be published in any form at any time in the usual way.

10. The CFHT Executive Director, acting upon advice from the CFHTLS Science Steering Group, may authorize the installation of near real time analysis systems (RTAS's) at the CFHT base facility in Waimea.  Such RTAS's must have limited and clearly stated scientific goals. The fundamental criterion for installing (or maintaining) an RTAS is that follow-up observations are required before results can be obtained from the anticipated general release date in order to achieve a stated science goal.

11. It is understood installed RTAS's may access the data only for the purpose of achieving their stated scientific goals. Images accessed by the RTAS's may not be copied to any transportable media nor exported from the CFHT site by any means.  In the case of the RTAS's, it is anticipated that there will be co-operation and collaboration between groups in the participating communities in the dissemination of detected objects.

12. Users of CFHTLS data should include an acknowledgement in all publications as follows:

This work is based in part on data obtained as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of the National Research Council of Canada and the French Centre national de la recherche scientifique.

Users of the advanced data products should include an acknowledgement in all publications as follows:

This work is based in part on data products produced at the Canadian Astronomy Data Centre and Terapix as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of the National Research Council of Canada and the French Centre national de la recherche scientifique.



Explanatory Note: The CFHTLS community of registered users

The CFHT Executive Director is charged with administering a system of registering eligible persons to become users of the CFHTLS data. In general, only registered individuals will have access to the proprietary CFHTLS data.

The eligibility of individuals to receive proprietary access to the CFHTLS data is extended to:
· All persons engaged in astronomical research residing in France and Canada (includes students and post-doctoral fellows as well as employed professional astronomers as Universities and Research Institutes).
· Members of the CFHT scientific staff.
· Professional astronomers employed at Research Institutes or Universities outside of Canada or France, but who are directly or indirectly supported by either NRC or CNRS, or another French or Canadian agency (e.g., a French Astronomer at ESO, a Canadian astronomer at JAC).

Individuals who do not fit the stated eligibility criteria but nevertheless believe they may be eligible to be included in the CFHTLS community may apply, stating their argument,  to the CFHT Executive Director for authorization to register.

Previously registered users whose status changes to one that no longer fits the stated eligibility criteria will normally be removed from the list of authorized users (their registration will be revoked). Such individuals may appeal to the Executive Director, stating their reasons to continue as a registered user of the CFHTLS.

Notes:

The registration form will contain a statement of the obligations associated with access to the data, especially regarding the proprietary nature of the data (i.e. (6)-(8) above), and the requirement of an acknowledgement (12).