A system and method for acoustically measuring a curved object are described. A flexible sheet is provided with an array of acoustic transducers. The flexible sheet is wrapped around the curved object such that the acoustic transducers acoustically contact the curved object. The acoustic transducers are used to generate and/or measure acoustic waves at variable locations depending on a shape of the curved object. Spatial coordinates of the acoustic transducers are determined while the flexible sheet is wrapped around the curved object. In particular, the spatial coordinates are determined based on respective subsets of travel times used to calculate respective wave directions of the acoustic waves arriving at respective subarrays from a common origin, e.g. scattering element inside the curved object.