In microscale particle velocimetry, the spatial resolution of velocity measurements along the
optical axis is often degraded by signal from tracer particles outside the focal plane.
Structured illumination microscopy particle tracking velocimetry (SIM PTV) can eliminate
most of this out-of-focus signal by using illumination with a non-zero spatial frequency to
preferentially illuminate the in-focus particles. Two such (raw) images can then be combined
to eliminate the background signal and demodulate the image. The objective of this study�…

In microscale particle tracking velocimetry (μPTV) images, the tracer particles beyond the
focal plane can degrade contrast and introduce measurement errors. Structured-illumination
microscale particle tracking velocimetry (SI μPTV) is an imaging technique that adapts
structured-illumination microscopy (SIM) for use in enhancing the axial spatial resolution of
images of tracer particles in a flow. SI μPTV takes two``raw''images modulated with a
sinusoidally varying intensity profile (ie, acquired with``structured''illumination) with a phase�…