Gravitational Lensing Accuracy Testing 2010 (GREAT10) Challenge Handbook
  GRavitational lEnsing Accuracy Testing 2010 (GREAT10) is a public image
analysis challenge aimed at the development of algorithms to analyze
astronomical images. Specifically, the challenge is to measure varying image
distortions in the presence of a variable convolution kernel, pixelization and
noise. This is the second in a series of challenges set to the astronomy,
computer science and statistics communities, providing a structured environment
in which methods can be improved and tested in preparation for planned
astronomical surveys. GREAT10 extends upon previous work by introducing
variable fields into the challenge. The "Galaxy Challenge" involves the precise
measurement of galaxy shape distortions, quantified locally by two parameters
called shear, in the presence of a known convolution kernel. Crucially, the
convolution kernel and the simulated gravitational lensing shape distortion
both now vary as a function of position within the images, as is the case for
real data. In addition, we introduce the "Star Challenge" that concerns the
reconstruction of a variable convolution kernel, similar to that in a typical
astronomical observation. This document details the GREAT10 Challenge for
potential participants. Continually updated information is also available from
http://www.greatchallenges.info.
