A method for calibrating an ultrasound probe includes directing the probe to receive ultrasonic waves reflected from a target that includes one or more linear elements, which are arranged to intersect the beam plane of the probe at respective intersection points. Signals are received from the probe responsively to the reflected ultrasonic waves, and the probe is aligned by modifying at least one of a position and an orientation of the probe responsively to the signals so that the intersection points occur in a desired location in the beam plane.
