McPhail M J, Fontaine A A, Krane M H, Goss L, Crafton J
Pennsylvania State University, Applied Research Laboratory, State College, PA 16804, USA.
Innovative Scientific Solutions Inc., 2766 Indian Ripple Road, Dayton, OH 45440, USA.
Meas Sci Technol. 2015 Feb;26(2). doi: 10.1088/0957-0233/26/2/025302. Epub 2015 Jan 7.
Color crosstalk and chromatic aberration can bias estimates of fluid velocity measured by color particle shadow velocimetry (CPSV), using multicolor illumination and a color camera. This article describes corrections to remove these bias errors, and their evaluation. Color crosstalk removal is demonstrated with linear unmixing. It is also shown that chromatic aberrations may be removed using either scale calibration, or by processing an image illuminated by all colors simultaneously. CPSV measurements of a fully developed turbulent pipe flow of glycerin were conducted. Corrected velocity statistics from these measurements were compared to both single-color PSV and LDV measurements and showed excellent agreement to fourth-order, to well into the viscous sublayer. Recommendations for practical assessment and correction of color aberration and color crosstalk are discussed.
使用多色照明和彩色相机时，颜色串扰和色差会使通过彩色粒子阴影测速技术（CPSV）测得的流体速度估计产生偏差。本文描述了消除这些偏差误差的校正方法及其评估。通过线性解混展示了颜色串扰的消除。还表明，可以使用比例校准或通过同时处理由所有颜色照明的图像来消除色差。对甘油充分发展的湍流管道流动进行了CPSV测量。将这些测量得到的校正速度统计数据与单色粒子图像测速（PSV）和激光多普勒测速（LDV）测量结果进行了比较，结果表明在直至粘性子层的范围内，四阶精度下二者吻合良好。文中讨论了对色差和颜色串扰进行实际评估和校正的建议。
