Affiliations: Massachusetts Institute of Technology, Department of
Mechanical Engineering, Room 3-246, Cambridge, MA 02139- 4307, USA. e-mail:
dphart@mit.edu
Abstract: This paper presents a method of accurately determining the
displacement of tracer particles between two images using recursive
correlation. The local correlation value is iteratively arrived at through
successive approximations of local displacement using increasingly smaller
regions of determination. By starting with a large search area and iteratively
narrowing the search restricting the search after each iteration based on the
resulting calculation, very high-resolution PIV processing can be achieved.
Spurious vectors are eliminated and accuracy and processing speed is maintained
by correlating images in compressed (sparse array) format using second-order
spatial correlation. The methodology of this unique image analysis method is
presented along with a discussion of its limitations and applicability.