As of October 17, the ~6 month time period for the GREAT3 challenge has begun, with submissions due by April 30, 2014. All 20 challenge branches are available for download.

In February, we revised our metric definitions and recalculated the Q values in all leaderboards, so do not be perturbed if you saw a change in your submission score! A description of the revised metrics, and an explanation for the revision, can be found here: Why_Update_Metrics.pdf.

If there is a tie for a non-zero score, the tie-breaking procedure in the handbook is applied. The winner then gets a single extra tie-break point.

Welcome to the Great3 Leaderboard

Great3 is a data analysis challenge for Weak Gravitational Lensing cosmology. Participants are given a large number of simulated images of distant galaxies and are challenged to compute and submit statistics about the underlying distortions that have affected the images.


This site is where challenge data can be downloaded and results submitted. For information on the challenge, see these sources:

Getting Started

Get the data

See the leaderboards (or submit a new entry to one of them)

See the teams

Team CEA-EPFL is in the lead with 80001 points (on a tiebreak)!