A plan for scanning an object using an array of ultrasonic transducers is prepared by identifying one or more enabled transducers for each of a plurality of selected grid positions defined on a surface of the object. The identification is made considering a direction of incidence of a planned ultrasonic signal emitted by each transducer, considering the array being positioned at each of the selected positions, and considering a surface normal vector at a grid position that would be impinged by the planned ultrasonic signal. The scan plan is complete when all grid positions defined on the surface of the array are covered by moving the array to all of the selected grid positions. The scan plan is executed by moving the array according to the scan plan while collecting, by the transducers enabled at each selected grid position, eventual responses to the ultrasonic signals from their respective grid positions.