A space-time dynamic model based on image warping

S. Aberg, F. Lindgren and A. Malmberg
Centre for Mathematical Sciences, Division of Mathematical Statistics
Lund University
Box 118, SE-221 00 Lund, Sweden
Phone: +46 46 2227974; Fax: +46 46 2224623
E-mail: s_aberg@maths.lth.se

Abstract
In this paper we present a spatio-temporal dynamic model which can be realized using image warping, a technique used to match images. Image warping is a non-linear transformation which maps all positions in one image plane to positions in a second plane. Using thin-plate splines this transformation is defined by a small set of matching points, a feature that will make this method work even for large data sets. In our case the dynamics of the process is described by warping transformations between consecutive images in the space-time series. Finding these transformations is a trade-off between a good match of the images and a smooth, physically plausible deformation. This leads to a penalized likelihood method for finding the transformation. The deformations that can be describedwith this approach include all affine transformations as well as a large class of non-linear deformations. Our method is applied to the problem of nowcasting radar precipitation.

Keywords: Dynamic models; Spatio-temporal modelling; Image warping; Thin-plate splines

In: McRoberts, R. et al. (eds).  Proceedings of the joint meeting of The 6th International Symposium On Spatial Accuracy Assessment In Natural Resources and Environmental Sciences and The 15th Annual Conference of The International Environmetrics Society, June 28 – July 1 2004, Portland, Maine, USA.

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