The use of FM pulse imaging scheme to obtain multispectral data from a speckle generating medium is discussed. Its potential for speckle reduction was evaluated by computing correlation coefficients. Measured coefficients were also compared with model predictions. The results are consistent with other published reports and show that significant speckle decorrelation can be achieved with this technique, if one averages frames acquired with center frequencies at the extreme ends of the transducer operating bandwidth, and a small enough Δf. At these extremes, the transducer response is low. This response limitation can, however, be overcome by increasing the linear frequency sweep time duration in the FM pulse imaging scheme. In a frequency dependent attenuating medium, proper choices of f o and Δf spanning the entire operating bandwidth of transducer may be necessary. The flexibility inherent in the FM pulse scheme can be exploited here (Refer to PDF file for exact formulas).
Date of creation, presentation, or exhibit
Department, Program, or Center
Chester F. Carlson Center for Imaging Science (COS)
Rao, Navalgund and Aubry, Mark, "Multispectral ultrasound imaging and analysis of speckle generating medium" (1993). Accessed from
RIT – Main Campus