Sequence Capture & Particle Tracking

Particle Image Sequence

The PIXCI® Imaging Board captures sequences of images at video rate. For example, the PIXCI® SV5 imaging board, and an RS-170 or NTSC camera, can capture 752x480 images at 30 fps, or can be throttled back for time lapse sequence capture. Images are captured with true pixel accuracy, neither compressed nor approximated, allowing precise analysis of particle position or velocity.

The PIXCI® D2X and CL1 imaging boards support many cameras with higher resolutions or higher frame rates than NTSC/PAL. For example, a PIXCI® D2X and a Dalsa CA-D1-064A camera can capture an image sequence at 2,900 fps. Or, a PIXCI® D2X and Redlake Megaplus 6.3i camera can capture images with 2Kx3K resolution. Overview of Software

After capture, the images can be analyzed by the XCAP Interactive Software, which automatically finds and tracks particles across the image sequence. The tracking parameters can be adjusted to include only particles of a specified mass (area) or a specified velocity.

After analysis, the particle tracks are reported numerically, as well as shown overlaid on the image for convenient visualization.

The image shown is the first of a sequence of nine, of a cylindrical reservoir containing liquid and a tubular heater which drives counter-clockwise rotating convection cells (courtesy of M. Wernet at the Nasa Lewis Research Center). Tracks of several particles are shown; each track is composed of head-to-tail arrows, illustrating the particle's track through the image sequence.