This article describes an experimental procedure for improving the detectability of small defects in composite
laminates based on modifications to the total focusing method (TFM) of processing ultrasonic array data to form an image. The TFM is modified to include the directional dependence of ultrasonic velocity. The maximum aperture angle is limited and a Gaussian frequency-domain filter is applied prior to processing. The parameters of maximum aperture angle, filter centre frequency and filter bandwidth are optimized.