Guoliang Li, Bo Xin, Wei Cui
Model fitting is frequently used in weak lensing studies to determine the shape of galaxies and the point spread function. However, the number of parameters in the model, as well as the number of objects, are often so large as to limit the use of this technique for future large surveys. In this article, we propose a set of algorithms to speed up the fitting process. The process is divided into three distinctive steps: centroiding, ellipticity measurement, and fitting. We demonstrate that we can derive the position and ellipticity of an object analytically in the first two steps and thus leave only a small number of parameters to be derived through model fitting. We assess the efficiency and accuracy of the algorithms with simulated images.
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http://arxiv.org/abs/1203.0571
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