On the basis of image cross correlation of brightness distribution and Fast Fourier Translation, the implementation of Particle image Velocimetry was studied.

在图像灰度分布互相关和快速傅立叶变换的基础上，研究了粒子图像测速的实现。

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The Kepler space telescope looks for planets by measuring tiny decreases in the brightness of stars when planets cross in front of them.

VOA: special.2011.02.09

Telescopes such as Kepler search for planets as they transit, or cross in front of, their star, causing telltale dips in the star's brightness.

MSN: News editor