A stylus-tracking device may include a piezoelectric receiver or transceiver array on a first side (e.g., underneath) a display. Image data may be acquired from the piezoelectric receiver array. The image data may correspond to signals produced by the piezoelectric receiver array in response to an acoustic signal and/or a mechanical deformation caused by a target object (e.g., a stylus) in contact with a surface, such as a cover glass, proximate a second side of the display. A doublet pattern in the image data may include a first area of having signals below a threshold level and a second area having signals above the threshold level. Based on one or more doublet pattern characteristics, a position of the target object on the surface, a force of the target object on the surface and/or a first direction of movement of the target object relative to the surface may be estimated.