论文标题
关于PIV测量统计的噪声
On the noise in statistics of PIV measurements
论文作者
论文摘要
本文认为，当使用PIV测量湍流时，它可以视为时间依赖的信号。 “输出”速度由三个主要贡献组成：时间依赖性速度，量化（或像素化）引起的噪声以及噪声贡献的噪声贡献，即审问体积内的速度并不统一。对于后者，它们的差异在此审问体积中取决于粒子或图像的平均数量）。这三个都是通过审讯窗口的有限范围进行空间过滤的。由于上述噪声与单个颗粒（或粒子图像）直接相关，因此不同实现和不同审问量之间的噪声在统计上是独立的。
It is argued herein that when PIV is used to measure turbulence, it can be treated as a time-dependent signal. The `output' velocity consists of three primary contributions: the time-dependent velocity, a noise arising from the quantization (or pixelization), and a noise contribution from the fact that the velocity is not uniform inside the interrogation volume. For both of the latter their variances depend inversely on the average number of particles or images) in this interrogation volume. All three of these are spatially filtered by the finite extent of the interrogation window. Since the above noises are associated directly with the individual particles (or particle images), the noise between different realizations and different interrogation volumes is statistically independent.
